The 17th International
Hydrocolloids Conference

Program Thursday - updated Nov. 3 🖶

Lecture Hall   |   |  
 Time      
  Session Chair: Mingyong Xie    
 8:30- 9:10 P3-241 Stefan Kasapis, Free volume vs molecular interactions in the structure-function relationships of high to low solid food systems    
 9:10- 9:50 P4-247 Aiqian Ye Intragastric colloidal behaviours and restructuring: manipulating the digestive outcomes    
 9:50-10:30 P5-228 Qi Wang Microencapsulation and target delivery of antibiotic alternatives by natural hydrocolloids for organic farming    
10:30-11:00 Break Break Break
  Session Chair: Alejandra Acevedo-Fani Session Chair: Li Day  
11:00-11:30 I7-242 Dan Ramdath, Promoting food-based dietary guidelines to improve carbohydrate quality and chronic disease prevention I9-184 Brad Forrest, Towards a more detailed understanding of dysphagia beverages  
11:30-12:00 I8-237 Yongfeng Ai, Manipulating starch digestibility in human and pet foods through extrusion technology I10-208 Philip Wescombe, Development and application of a new clean label citrus fibre hydrocolloid  
12:00-13:10 Lunch/Poster Lunch/Poster Lunch/Poster
 Time      
  Session chair: Elke Scholten Session chair: Yongfeng Ai Session chair: Munish Puri
13:10-13:30 C31-230. Effect of modified β-lactoglobulin on the stability of algae oil emulsion: storage, environmental and oxidative stability C41-204. In vitro gastric digestion of pea protein using a human stomach simulator: effects of heat treatment C51-195. Texturization of Plant-Based Products: Strengthening Pea Protein Gels with Collagen and Enzymatic Crosslinking
13:30-13:50 C32-212. Temperature-induced Release of Salt from Double Water-in-Oil-in Water Emulsion Made with Coconut Oil. C42-215. Impact of Extraction Processes and Cell Wall Structure on Crude Protein Digestibility of Macroalgal and Microalgal Proteins C52-205. Heat-induced interactions between microfluidized hemp protein particles and caseins or whey proteins
13:50-14:10 C33-123. Evaluation of alginate/lactoferrin composite hydrogel properties as a polyphenol encapsulation agent C43-152. Effects of fibrous structure of textured-vegetable-protein (TVP)-based meat analogues on the protein digestibility and absorption properties C53-200. Quinoa protein fibrillation at pH 7 facilitated by bromelain hydrolysis and CaCl2
14:10-14:30 C34-185. Physicochemical properties of hybrid cheddar cheese gels made from cow-milk and plant protein isolates C44-231. Effect of soybean processing by products (Okara) incorporation on the physicochemical properties and in vitro digestion behavior of tofu gel C54- 149. Synergistic effects of alkaline treatment and mild heating on mung bean protein isolate for enhanced plant‑based meat patty quality
14:30-14:50 C35-131. Molecular Dynamics Simulation of Hydrocolloid Hydration C45-214 Investigation of the gastric digestion behavior of commercial infant formulae using an in vitro dynamic infant digestion model C55-193. Structural changes and the gelling behaviour of plant proteins processed by ultrasound
14:50-15:10 C36-142. Atomic force microscopy of emulsion interfaces and their nanoparticles at the nanoscale C46-227. In vitro digestion and fermentation characteristics of eight kinds of pulses and suggestions for different populations C56-206. Effect of Rheology in High Moisture Extrusion of Commercial Soy Proteins
15:10-15:30 Break Break Break
  Session chair: Lara Matia-Merin Session chair: Yong-Cheng Shi Session chair: Dan Ramdath
15:30-15:50 C37-173. Unraveling microstructure and water behavior in diverse food matrices using low-frequency NMR on proton. C47-105. In-vitro starch digestibility from different types of starch and the effect of phytic acid on starch digestion C57-104. Impact of thermosonication at neutral pH on the structural and physicochemical properties of faba bean protein isolate dispersions
15:50-16:10 C38-235. Utilizing capillary forces to structure protein oleogels. C48-115. Starch structure and food microstructure contribute to reduced starch digestibility and aging of high-amylose wheat food C58-209. Composition, physicochemical, and structural properties of black gram (Vigna mungo) proteins
16:10-16:30 C39-167. Multidimensional spectroscopy reveals the nature and intensity of polysaccharide-polyphenol interactions C49-253. Texture, microstructure, and in vitro digestion of hybrid meat analogues formulated with functionalized pea protein C59-126. Exploring the potential of flour and protein isolates of mung bean, cowpea, and soy for the application in plant-based meat alternatives: A comprehensive analysis of physicochemical, functional, structural, thermal, and nutritional properties.
16:30-16:50 C40-140. Designing of Nanocapsules of Curcumin Using Native Casein Micelles and Their Characterization C60-128. Exploring the impact of bovine milk composition on milk-tea attributes: insights from adjusting protein, carbohydrate, fat, and tea profiles
18:30-22:00 Conference Banquet Conference Banquet Conference Banquet

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184Towards a more detailed understanding of dysphagia beverages

Graham Sworn; Florian Nettesheim; Brad Forrest*

International Flavours & Fragrances Inc.
Dysphagia is a perennial health challenge in the elderly as well as other groups. With aging populations in many regions of the world, the incidence can only be expected to increase. Poor swallow mechanisms in afflicted populations can lead to malnutrition and aspiration pneumonia amongst other morbidities.

Over several years, a body of empirical evidence has emerged supporting that thickening of fluids is an effective intervention in enhancing safe swallowing and reducing the risk of aspiration. In the case of beverages, including water, this has been achieved through use of hydrocolloids - commonly but not exclusively, starches and xanthan.

Whilst progress has been made in describing various thicknesses of foods and beverages from the standpoint of standardised preparation in the nursing environment, quantitative description of optimal rheological properties remains a topic of active investigation.

In this paper we seek to present a review of key learnings in this field and thence demonstrate the place of extensional rheology as an important feature of a fluid proposed for use in enhancing safe swallowing for those suffering oropharyngeal dysphagia.

208Development and application of a new clean label citrus fibre hydrocolloid

Ying Xu1, He Jia22, Philip Wescombe3, Jun Xu1,

1 Inner Mongolia Dairy Technology Research Institute Co. Ltd, Hohhot 010110, China
2National Center of Technology Innovation for Dairy, Hohhot 010110, China
3National Center of Technology Innovation for Dairy - Oceania Innovation Center, Lincoln 7647, New Zealand
Introduction: Cheese is an emerging dairy category in China which has high growth potential but also significant scope for innovation as expectations of what cheese should taste like have not yet be defined for the Chinese consumer. To develop a low-fat cheese suitable for the China market, Yili Group, a leader in the dairy industry within China, has developed a novel clean label citrus fiber with hydrocolloid properties to provide improved taste, texture and melting performance for cheese slices.

Methods: A process to extract citrus fiber from juiced sweet oranges was developed and the properties of the new fiber have been explored using traditional techniques such as measuring the water holding capacity, effects of shear on viscosity and texture, EM for microstructure visualization and finally sensory evaluation. The fiber was then used in a low fat processed cheese and consumer testing carried out compared to a control with no added fiber.

Results: A commercially viable extraction process was developed for the sweet orange citrus fiber. The fiber was found to have higher water retention properties than other tested plant fibers with suitable properties for use in gel formation. Compared to xanthan gum and carboxymethyl cellulose, the citrus fiber had higher texture hardness properties but lower viscosity. It was successfully commercialized into a low fat cheese product with improved consumer perception for texture, melting characteristics in the mouth and moisture content. The citrus fiber was also explored for application in yoghurt to replace starch and pectin expanding the application range of the ingredient.

Discussion: The new citrus fiber has significantly higher water retention with excellent gel thickening properties when compared to other plant fibers. On the palate it is delicate and soft without coarseness or a grainy feel and provides fatty taste. Overall, citrus fiber provides a superior easy to use, clean label replacement for fat or carbohydrates, and has been successfully applied to processed cheese slice manufacture in China with potential for application in yoghurt and ice cream in the future.

237Manipulating starch digestibility in human and pet foods through extrusion technology

Yikai Ren, Fan Cheng, Yongfeng Ai*

Department of Food and Bioproduct Sciences, University of Saskatchewan, Canada
Extrusion is a versatile and effective processing technology that applies mixing, conveying, kneading, shearing, cooking, melting, structuring, and/or shaping to modify raw ingredients as well as to transform them to human foods, pet foods, and animal feeds. During the modification and transformation, starch can play important roles as a gelling agent, binder, texture provider, stabilizer, and energy source. Flours of round pea, lentil, faba bean, and wrinkled pea were utilized as the sole starch source to produce dry pet foods through extrusion, along with rice flour as the control. All the diets were formulated to provide the same levels of starch (~20%) and other nutrients. Wrinkled pea pet foods showed noticeably lower damaged/gelatinized-starch contents and less molecular breakdown than the rice and normal pulse samples, which explained the considerably lower in vitro and in vivo starch digestibility of the former. To further reduce starch digestion, extruded pet foods were prepared using rice (control), round pea, and wrinkled pea flours with rosemary extract (RE) incorporated at levels of 0, 1.0, 10.0, and 30.0 g/kg (designated as RE0, RE1, RE10, and RE30, respectively). RE10 and RE30 significantly decreased in vitro starch digestibility of pet foods, with the highest reduction observed for the high-amylose wrinkled pea sample. Although RE1 did not significantly influence the in vitro and in vivo starch digestibility, this treatment consistently delayed the peak times of postprandial blood glucose responses to all the three extruded diets in beagles. In a separate study, extrusion was combined with high-temperature drying (EHTD) to modify round pea starch: extrusion with 37.5% moisture and a low-temperature profile (< 65°C), followed by immediate heating at 130°C for 1 h. Overall, EHTD increased gelatinization temperatures and decreased gelatinization enthalpy change, lowered pasting viscosity and gel hardness, as well as enhanced enzymatic resistance of pea starch. More interestingly, in a human feeding trial (n = 20 healthy subjects) to determine plasma glucose response over a period of 2 h after consuming water-boiled samples (containing 35 g dry starch), EHTD-modified pea starch displayed 22% reduction (p < 0.01) in plasma glucose incremental area under the curve in comparison with the native sample. This presentation will highlight novel findings of selecting suitable raw materials and designing extrusion processes to control starch digestibility in extruded products.

242Promoting food-based dietary guidelines to improve carbohydrate quality and chronic disease prevention

Dan Ramdath1,2, Simon G. Anderson2, Cyril W.C. Kendall3, Simin Liu4, David J.A. Jenkins3, John L. Sievenpiper3

1Caribbean Public Health Agency
2University of the West Indies, Barbados
3University of Toronto, Canada
4University of California, Irvine, USA.
Introduction: The continued obesity pandemic and its associated risks for non-communicable chronic diseases (NCDs) have been linked to various dietary components, diet quality, and availability of healthy foods. However, several dietary patterns, including the Mediterranean, Portfolio, Nordic, Dietary Approach to Stop Hypertension (DASH) etc., continue to be evaluated for their protective effects against NCD risk. Yet, much remains to be learnt about the impact of specific macronutrients on NCDs, particularly in diverse populations from low-and middle-income countries. Moreover, the abundance of relatively inexpensive calorie-dense foods in a global Westernized environmental culture presents a major challenge for individuals to adopt healthy eating behaviours. In this review, we critically examined available studies to determine carbohydrate quality, which included metrics such as glycemic index (GI), glycemic load (GL), and glycemic control; the LDL-cholesterol lowering effect; and overall diet quality. These metrics were reconciled against morbidity and mortality outcomes including NCD risk reduction.

Methods: Assessment of the available literature with specific emphasis on the roles of healthy dietary patterns in the prevention and management of NCDs

Results: Except for the DASH diet that allows for generous servings of lean meats, the dietary patterns evaluated were all rich in minimally processed whole grains and plant-based foods. The strongest evidence to date comes from the PREDIMED study, one of the largest randomized-controlled foods-based trial of Europeans, demonstrating exceptionally effective of the Mediterranean diet in reducing the incidence of major cardiovascular events while significantly lowering dietary GL and GI. This is consistent with a large of body of literature showing that a diet with a high GI and GL was associated with an increased risk of NCDs and mortality. In parallel, these studies also show that the plant-based, low GI and GL, Portfolio Diet was equally effective in reducing LDL-C, glycemic control and cardiovascular risk. There is currently ongoing implementation of the Portfolio Diet as part of food-based dietary interventions in free-living at-risk individuals; preliminary results show high efficacy in NCD risk reduction. In contrast, diets high in refined carbohydrates, particularly free or added sugars, have been associated with significantly increased NCD risk.

Discussion: Plant-based dietary patterns with small amounts of lean meats, fish and healthy fats improve diet carbohydrate quality, reduce dyslipidemia and are associated with lower NCD risk and a decrease in CVD mortality.

228Microencapsulation and target delivery of antibiotic alternatives by natural hydrocolloids for organic farming

Qi Wang1*, Steve Cui1, Joshua Gong1, Nasser Ibrahim1, Antonet Svircev2, Hanay Anny1

1Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada
2London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
The global environmental crisis and consumer health consciousness have led to increased attention to organic farming. Organic farming not only produces healthier foods, but also leaves fewer chemicals that pollute the waters and soil. Reduction of antibiotic use in agricultural production has been a big challenge to organic farming and the search for using natural bioactive substances to replace conventional antibiotics has intensified. Probiotics, bacteriophage, and essential oils are promising candidates as antibiotic alternatives. Effective protection and delivery of these bioactives to their target sites is a critical step toward the success of such applications. Although encapsulation is shown to be effective in such applications, the selection of encapsulation wall materials that meet organic farming requirements has been a big challenge. This presentation will use two examples to demonstrate the quest for natural hydrocolloids to be applied to encapsulation and delivery of antibiotic alternatives that meet organic farming requirements. One example is for intestinal delivery of essential oils for disease control and improvement of gut health in animals; the other is for delivery of a bacteriophage-based biopesticide for disease control in fruit trees. Various encapsulation techniques, including emulsification, spray drying, and freeze drying are compared and selected according to the respective applications. The results demonstrated that natural hydrocolloids are irreplaceable as encapsulation wall materials for target delivery of bioactive substances as antibiotic alternatives in organic farming.

247Intragastric colloidal behaviours and restructuring: manipulating the digestive outcomes

Aiqian Ye

Riddet Institute, Massey University, New Zealand
Colloidal behaviour of food during digestion plays an important role in the breakdown, gastric emptying, digestibility of food components, which depends on the interaction between the food components and physiological secretion and action. The coagulation and aggregation of milk proteins under gastric conditions to form a structured coagulum is a unique interaction between food source and physiological secretion pepsin and acid. The interaction takes place in various types of food containing milk proteins, such as milk, plant-based milk, infant formulae, gel-type dairy products and emulsion-type beverages, which result in a variety of colloidal phenomena under gastric digestion, for examples, clotting, aggregation, flocculation/creaming and gelation. The protein composition, source, processing treatments and the presence of other food components influence the interactions, hence the colloidal behaviours and the structure of stomach chyme. These colloidal behaviours in the stomach have an impact on the digestion of protein, lipid and other nutrients by controlling the kinetics of protein hydrolysis, disintegration of the formed structure and gastric emptying. This presentation updates our recent work on the interactions between protein and pepsin and the dynamic in vitro digestion of protein and fat from various food products (i.e. dairy and plant-based foods) with various compositions and treatments. This work highlights how various matrices formed under gastric conditions can govern the fate of health by manipulating the macronutrient delivery and digestion of food products.

241Free volume vs molecular interactions in the structure-function relationships of high to low solid food systems

Stefan Kasapis

School of Science, RMIT University, Bundoora West Campus, Melbourne, Vic 3083, Australia
In soft matter physics, the problem of correctly describing the mobility and dynamics of molecular motions in polymers and co-solutes is very difficult. In this context, volume changes and hence free volume is a popular concept due to it being intuitively appealing. Often (but not invariably) is able to explain observed trends correctly, and it is easy for workers in polymer science – coming from many different backgrounds - to use. It appears that beyond free volume there are not many viable alternatives. The concept of configurational entropy and the relation it has to the transformation from the melt state to the rubbery consistency and the glass transition represents probably the only other approach that has often been used as an alternative, but it is much harder to understand and master in the structural properties of biomaterials [1].

Nevertheless, in a pioneering communication [2], Ngai and Plazek pointed out that in physics volume or free volume is not the most fundamental physical quantity one can imagine for use to describe dynamics in a structured system such as a biopolymer network. They argued that intermolecular interactions are more fundamental and the ultimate determining factor, but it is nontrivial to construct a theoretical framework starting from interactions because that is a many body problem. Intermolecular interactions, they said, determine volume but not vice versa. We have recognised in our research that the free volume concept cannot capture all the physics of molecular mobility in food systems of biopolymer, bioactive compound and other co-solutes [3].

Therefore, the present review aims to discuss the aforementioned statements, and in the process to touch upon some interesting physicochemical mechanisms in food systems, in order to recognise limitations in various mechanistic models depending on application. Regarding the application of the concept of the glass transition temperature on molecular transport of bioactive compounds and lipid oxidation in relation to the structural morphology of the delivery vehicle, the concept of free volume is the governing molecular process, as seen for bioactive cargos like nicotinic acid, caffeine and linoleic acid [4]. However, in low- and intermediate-solid food systems, vitamin diffusion through composite biopolymer gels or phenolic compound diffusion through single phase dairy protein preparations argue that free volume is supplanted by intermolecular interactions in the hydrated counterparts as the most fundamental physical quantity [5]. It is possible that a fundamental approach based on molecular interactions will probably validate in the future their application on many problems

  1. References
  2. Jiang, B., Kasapis, S. & Kontogiorgos, V. (2011). Combined use of the free volume and coupling theories in the glass transition of polysaccharide/co-solute systems. Carbohydrate Polymers, 83, 926
  3. Ngai, K.L. & Plazek, D.J. (1995). Identification of different modes of molecular motion in polymers that cause thermorheological complexity. Rubber Chem. Technology, 68, 376.
  4. Kasapis, S. (2008). Recent advances and future challenges in the explanation and exploitation of the network glass transition of high sugar / biopolymer mixtures. Critical Reviews in Food Science and Nutrition, 48, 185.
  5. Sidhu, M.K., Whitehead, F. & Kasapis, S. (2023). Diffusion kinetics of vitamin B6 from phase separated gelatin and agarose gels using blending law modelling. Food Hydrocolloids, 139, 108519.
  6. Ikasari, D., Paramita, V.D. & Kasapis, S. (2023). Mechanical vs calorimetric glass transition temperature in the oxidation of linoleic acid from condensed -carrageenan/glucose syrup systems. Food Hydrocolloids, 139, 108555

104Impact of thermosonication at neutral pH on the structural and physicochemical properties of faba bean protein isolate dispersions

Yinxuan Hu1, Lirong Cheng2*, Elliot Paul Gilbert3, Sung Je Lee1, Zhi Yang1*

1School of Food and Advanced Technology, Massey University, Auckland, 0632, New Zealand
2Riddet Institute, Massey University, Palmerston North, 4472, New Zealand
3Australian Centre for Neutron Scattering, ANSTO, New Illawarra Road, Lucas Heights, NSW 2234, Australia
The effect of thermosonication (TS) (90 °C, 10-30 min) on faba bean protein isolate (FPI) at pH 7 was investigated. The microstructural and techno-functional properties of TS-treated FPI were compared with native FPI or FPI treated with conventional prolonged heating (CH, up to 8 h) at 90 °C. TS treatment effectively converted FPI to elongated fibrillar-like aggregates containing predominant β-sheet secondary structures, as determined by Thioflavin T (ThT) fluorescence and circular dichroism (CD). These elongated particulate aggregates could be formed by disulfide bonds as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Additionally, TS treatment is efficient in disrupting large protein aggregates of FPI, thus improving their solubility. Both TS and CH treatments induced formation of viscoelastic FPI hydrogels, and whose gel strength depends on the type and time of treatment. Hydrogels formation is likely to arise from the entanglement and interaction of elongated particulate aggregates as revealed by small angle neutron scattering (SANS) and scanning electron microscopy (SEM). TS-treated FPI was also used to prepare O/W emulsions and whose structural and physical properties were compared with those stabilised by untreated FPI. At all oil volume fractions (ϕ=0.2, 0.5, and 0.7) and FPI concentrations (1, 3, and 5 wt %), emulsions stabilised by TS-treated FPI exhibited smaller oil droplet size, greater mechanical strength and superior stability compared to those stabilised by untreated FPI. The study suggests that TS treatment is promising in improving techno-functional properties of FPI; further studies are needed to exploit TS-treated plant proteins as a novel food ingredient in food product development.

105In-vitro starch digestibility from different types of starch and the effect of phytic acid on starch digestion

Shu Cheng, Yongmei Sun, Mia Thorburn, Jingying Cheng, Zexin Lei, Timothy A.G. Langrish*

Drying and Process Technology Research Group, School of Chemical and Biomolecular Engineering, The University of Sydney, Camperdown, NSW, 2006, Australia
The starch digestion process has a significant value in the human diet. The in-vitro digestibility of starch has been studied in this work, including the reasons for different starches (potato, corn, and wheat) having different in-vitro digestibilities and the mechanisms for the inhibition of starch digestion by phytic acid. In-vitro starch digestion results show that the digestibility of wheat starch is higher than that for potato starch and corn starch. This study has analysed the particle sizes, degrees of crystallinity and the compositions of the different starches, and a significant difference between the starches that affects digestion is the composition of amylose. Amylose is more slowly digested than amylopectin. Wheat starch has a lower amylose content than corn and potato starch, which may cause wheat starch to have higher digestibility. This study also assesses the effects of phytic acid on starch digestion. In a buffer solution, the pH value is around 6.9, a-amylase activity is high, and the inhibitory effect of phytic acid on starch digestion is not obvious. In water, the pH value is around 4, a-amylase activity is low in this pH environment, and phytic acid has a significant inhibitory effect on starch digestion. This study helps to understand the digestion process of starch and provides two methods to change the digestibility of starch, which may assist in the development of low-glycemic index (low-GI) diets.

115Starch structure and food microstructure contribute to reduced starch digestibility and aging of high-amylose wheat food

Caili Li1,3, Sushil Dhital1,2, Michael J. Gidley1

1The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia
2Department of Chemical and Biological Engineering, Monash University, Clayton, VIC, 3800, Australia
3Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin, 300071, China
Enhancing starch-based food hydrocolloid properties through use of recently commercialised high amylose wheat starch is a promising way to improve food quality and deliver potential health benefits. Incorporation of high amylose wheat flour (HAWF) reduced both the rate and degree of starch digestion in foods (e.g. bread, tortillas, and noodles), and elevated nutritionally beneficial resistant starch (RS) levels. More retained crystalline structure in starch and compact microstructure of the high-amylose wheat food contributed to this. In addition, wheat bread prepared from part or all HAWF with amylose content (AM) 71% or 84% had limited storage-induced changes, including firmness and starch retrogradation. Firmness of bread was positively related to AM content and melting enthalpy of recrystallized amylopectin (ΔHAP). ΔHAP increased significantly on storage for wild type (32% AM), only slightly for 71% AM but not at all for bread with 84% AM. Higher water content was needed to make doughs from HAWF, due to the greater protein content in flour and loose packing of polymers within HAWS granules, and also leads to a more plasticized crumb network and hinders crumb aging.

123Evaluation of alginate/lactoferrin composite hydrogel properties as a polyphenol encapsulation agent

Winda Christina Harlen1,3, Sri Yuliani2, Sangeeta Prakash1, Bhesh Bhandari1.

1School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, Queensland 4072, Australia
2Research Center for Agroindustry, Research Organization for Agriculture and Food, National Research and Innovation Agency, Tangerang, Indonesia
3Widya Mandala Catholic University Surabaya, Surabaya 60265, Indonesia
*Corresponding author. Email: b.bhandari@uq.edu.au
Alginate is a hydrocolloid that is commonly used to encapsulate hydrophilic polyphenols due to its biocompatibility and versatility. Nevertheless, encapsulation with alginate has few drawbacks, such as burst release mechanisms and loss through diffusion during gel formation and storage. Previous studies have demonstrated the compatibility of both lactoferrin-based and alginate-based encapsulation agents, however, limited research has explored the combined use of these polymers as encapsulation agents for hydrophilic polyphenols. Therefore, the aim of this research is to investigate the performance of lactoferrin-alginate combination in the form of composite gel as an encapsulation agent for gallic acid, which represents water-soluble polyphenols. The physical properties of the gel and the diffusion of gallic acid throughout the gel were evaluated. Composite gel with different ratios of sodium alginate-lactoferrin in solid basis were prepared (1:0, 1:1, 2:0, 2:1, 2:2, and 2:3) and evaluated for initial solution viscosity, gel syneresis, gel strength and stiffness, dried gel rehydration and gel porosity properties as well as gel microstructure. The interactions between alginate-lactoferrin and gallic acid were evaluated by zeta-potential analysis and FTIR spectroscopy. It was found that the composite gel with the ratios of alginate to lactoferrin in 2:1 and 2:2 exhibited better gallic acid retention within the gel than that the neat alginate gel due to their smaller gel porosity. More compact structures were created by evenly distributed lactoferrin in the gel system with higher proportion of lactoferrin as observed in the optical and CLSM microscopy images. FTIR analysis revealed hydrogen interactions between lactoferrin and gallic acid phenolic groups. Incorporation of lactoferrin in the alginate composite gel significantly improved the gallic acid retention in gallic acid-loaded gel (87.1-92.2%). Gel electrophoresis analysis demonstrated that the composite alginate-lactoferrin gel effectively prevented the diffusion of compounds with molecular weight greater than 50 kDa. This study provides valuable insight for the development of hydrogel-based encapsulating materials for polyphenols.

Keywords: Alginate composite gel, Lactoferrin, Gel physical properties, Gallic acid diffusion

126Exploring the potential of flour and protein isolates of mung bean, cowpea, and soy for the application in plant-based meat alternatives: A comprehensive analysis of physicochemical, functional, structural, thermal, and nutritional properties.

Malsha Dinali1,2, Jayani Chandrapala1*., Mayumi Silva1., Benu Adhikari1., Lisa Newman1, Rumesh Liyanage2., Isuru Wijesekara2.

1School of Science, RMIT University, Bundoora, VIC 3083, Australia.
2Department of Biosystems Technology, Faculty of Technology, University of Sri Jayewardenepura, Pitipana 10206, Sri Lanka.
*corresponding author (authors in order of importance)
Meat consumption has long been a dietary staple, providing essential nutrients for centuries. However, the global rise in population and income has led to increased meat consumption, particularly processed meats, raising concerns about health and environmental impacts. Animal-based food production negatively contributes to greenhouse gas emissions and deforestation, while excessive meat intake is also associated with health risks such as cancer and heart disease. Ethical concerns about animal welfare also drive interest in meat alternatives. Consequently, there's a growing demand to explore alternative proteins as sustainable and healthy options. While soybean proteins have been predominant in meat alternatives, research now focuses on alternative sources like rapeseed, faba bean, oat, chickpea, pea, and hempseed to diversify options and promote sustainability.

The present study explores the potential of flour and protein isolates from mung bean, cowpea, and soybean as protein sources for plant-based meat substitutes. Functional, structural, pasting, thermal, and nutritional characterization was conducted using Fourier-transform infrared spectroscopy (FTIR), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), scanning electron microscopy (SEM), rapid visco analyzer (RVA), differential scanning calorimetry (DSC), Inductively coupled plasma mass spectrometry (ICP-MS), and chromatographic techniques.

Both flour and protein isolates displayed higher protein content, making them suitable for enriching high-protein meat alternatives. The high water absorption capacity of the flours suggests their potential in flavor retention, enhancing palatability, and extending the shelf life of meat products. Results from the study indicated that flour and protein isolates could serve as valuable nutritional sources closely similar to meat, given their high mineral and amino acid content contributing significantly to human diet and nutrition. Despite variations, both sources could contribute significantly to essential micronutrients, emphasizing their potential in fulfilling dietary requirements, particularly in plant-based diets. SEM images of the flour and protein isolates revealed distinctive surface microstructures. The milling process uncovered starch granules and disrupted protein matrices in flours, while freeze-dried protein isolates exhibited densely clustered irregularly shaped flakes. SDS-PAGE showed that mung beans were characterized by the 8S globulin, cowpea exhibited prominent globulins and minor albumin bands, and soy proteins featured β-conglycinin and glycinin subunits. Understanding these differences is crucial for diverse applications in food science and nutrition. FTIR spectroscopy analysis has also been conducted to support and further identify the structural characteristics where flour and protein isolates revealed unique secondary structures, notably, flour exhibited a notable presence of random coils, while the prevalence of β-structures, especially β-sheets, significantly influenced protein digestibility and thermal stability. Pasting properties of legume flours, including mung bean, cowpea, and soy, exhibited significant differences influenced by factors such as starch content, protein content, and fat composition, playing a crucial role in determining the cooking behaviour and textural attributes of meat alternatives. Furthermore, DSC analysis revealed distinct thermal properties of flour and protein isolates, crucial for thermal processing such as extrusion to ensure protein denaturation, influencing the texture for plant-based meat analogues.

The findings of the study offer valuable insights into the development of plant-based meat alternatives, exploring the enhanced functional performance of flour and protein isolates.

128Exploring the impact of bovine milk composition on milk-tea attributes: insights from adjusting protein, carbohydrate, fat, and tea profiles

Dilema Wijegunawardhana1,2, Jayani Chandrapala1*, Mayumi Silva1, Tuyen Troung2, Rumesh Liyanage3, Isuru Wijesekara4

1 School of Science, RMIT University, Melbourne, Australia
2School of Science, Engineering and Technology, RMIT University, Vietnam
3 Department of Biosystems Technology, Faculty of Technology, University of Sri Jayewardenepura, Homagama, Sri Lanka
4 Department of Food Science and Technology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda, Sri Lanka
Milk tea, a popular beverage worldwide, is enjoyed for its balance of tea and milk constituents, delivering an unparalleled sensory experience. While extensive research has focused on tea types and concentrations, the influence of bovine milk composition on milk-tea properties remains relatively unexplored. This study aims to unravel the intermolecular interactions between milk constituents, including protein, carbohydrates, fat, and tea, on milk-tea attributes, with a particular focus on the modulation of casein:whey ratio, lactose:maltodextrin ratio, fat availability, and tea concentration at different processing stages, including pasteurization, concentration, and spray drying. The study findings revealed that fat-filled milk tea formulations with 90:10 and 75:25 lactose:maltodextrin ratios showed heightened emulsion stability and reduced protein aggregation compared to other tested ratios, such as 100:0, 85:25, and 80:20. These effects stemmed from intensified electrostatic repulsion among particles, minor whey-casein binding facilitated by Maillard reactions, and unchanged protein secondary structures post-concentration. Interestingly, varying lactose:maltodextrin ratios preserved phenolic compounds in fat-filled milk tea post-concentration, attributed to diverse interactions such as electrostatic repulsion and Maillard reactions. Skimmed milk tea formulations exhibited reduced disulfide aggregation and electrostatic interactions with an 80:20 lactose:maltodextrin ratio, showcasing effective protein-lactose interactions. Phenolic compound preservation was enhanced with 90:10 and 80:20 lactose:maltodextrin ratios, attributed to increased whey-whey interactions and Maillard reactions. However, maltodextrin addition did not enhance phenolic retention as observed in fat-filled milk tea formulations. Further investigation involved varying casein:whey ratios, such as 80:20, 70:30, and 60:40, revealing synergistic effects between specific lactose:maltodextrin and casein:whey ratios. Skimmed formulations with 90:10 lactose:maltodextrin and 80:20 casein:whey ratios, and 80:20 lactose:maltodextrin with 70:30 casein:whey ratios, exhibited higher total phenolic content post-concentration. Fat-filled formulations with 90:10 lactose:maltodextrin and 70:30 casein:whey, and 75:25 lactose:maltodextrin and 70:30 casein:whey ratios displayed improved stability post-concentration. Further investigation into tea concentration levels (1%, 2%, 3%, and 5%) revealed higher total phenolic content with 5% tea concentration, indicating a concentration-dependent effect on phenolic content. Interestingly, significant increases in total phenolic content after concentration underscored the effective interplay among lactose:maltodextrin ratios, casein:whey ratios, and tea concentration. These findings suggest that adjusting the composition of bovine milk can enhance the qualities of milk tea after pasteurization and concentration. This opens up opportunities for future research and innovation in developing better beverage formulations.

131Molecular Dynamics Simulation of Hydrocolloid Hydration

E. Joseph, G. Lian, Chuan-Yu Wu

Department of Chemical and Process Engineering, University of Surrey, GU2 7XH, United Kingdom
The hydration properties of hydrocolloids are not only pivotal in determining their functionality in diverse applications such as foods [1], personal care products [2] and pharmaceuticals [3], but also critical in affecting their processibility in product manufacture and storage stability. The molecular mechanisms underlying the hydration behaviour of hydrocolloids are not fully understood, in particular how the molecular conformation of different hydrocolloids affects and responds to hydration. This research investigates the application of molecular dynamics method to simulate hydrocolloid structure and hydration dynamics. Progress has been made in developing a molecular dynamics simulation approach to investigate the conformation change and corresponding mobility and sorption isotherm of hydrocolloid molecules at different temperature and hydration levels. A detailed comparative simulation study has been conducted on corn starch with a focus on deriving water sorption isotherms and diffusivity. Different hydration levels are obtained by simulating Grand Canonical Monte Carlo (GCMC) insertion and deletion moves of water molecules using the python module, grand : Grand Canonical Sampling of Waters in OpenMM software. The MD simulations are performed using GROMACS software. The simulations employed the CHARMM forcefield. The simulated water sorption isotherm has been compared with experimental data obtained from Dynamic Vapor Sorption (DVS) measurements [4] and there is a good agreement.

The simulation results provide detailed insights into molecular interactions, such as self-diffusion coefficient, hydrogen bonding, and sorption characteristics of corn starch under various hydration conditions, all attributed to the inherent molecular structure and conformation changes. The amylose-to-amylopectin ratio is hypothesised to affect their interaction with water molecules. At low relative humidity (RH), water molecules are strongly bound to the starch matrix. As RH increases, more water molecules are available, and they start to occupy the available free spaces and interact more with each other, leading to higher mobility and a sharp increase in the diffusion coefficient. The simulations will also explore the starch-water interface, focusing on how water molecules interact with and affect the starch structural and physical properties.

    References:
  1. M. Krempel, K. Griffin, and H. Khouryieh, 'Hydrocolloids as Emulsifiers and Stabilizers in Beverage Preservation,' in Preservatives and Preservation Approaches in Beverages, Elsevier, 2019, pp. 427-465. doi: 10.1016/B978-0-12-816685-7.00013-6.
  2. 'Synthesis of Carboxymethyl Chitosan and its Rheological Behaviour in Pharmaceutical and Cosmetic Emulsions,' J. Appl. Pharm. Sci., 2017, doi: 10.7324/JAPS.2017.71010.
  3. E. Dickinson, 'Hydrocolloids acting as emulsifying agents - How do they do it?,' Food Hydrocoll., vol. 78, pp. 2–14, May 2018, doi: 10.1016/j.foodhyd.2017.01.025.
  4. G. Peng, X. Chen, W. Wu, and X. Jiang, 'Modeling of water sorption isotherm for corn starch,' J. Food Eng., vol. 80, no. 2, pp. 562-567, May 2007, doi: 10.1016/j.jfoodeng.2006.04.063.

140Designing of Nanocapsules of Curcumin Using Native Casein Micelles and Their Characterization

Ankita Hooda1, Bimlesh Mann2, Rajan Sharma3, Abhishek Dutt Tripathi1, Himanshu Kumar Rai4, Urvashi Vikranta5

1Assistant Professor, Department of Dairy Science and Food Technology, Bananas Hindu University
2ADG, ICAR, New Delhi
3Principal Scientist, Department of Dairy Chemistry, ICAR- NDRI, Karnal
4Technical Assistant, Department of Dairy Science and Food Technology, Bananas Hindu University)
5Doctoral Research Scholar: Department of Dairy Science and Food Technology, Bananas Hindu University
Global demand for functional food is increasing and nanoencapsulation has wide scope in achieving differentiation and enhancing value of foods by incorporating various nutraceutical into food matrices. Casein (80% of total milk protein) is responsible for delivering nutrients to neonates & has excellent functional properties, good digestibility, high nutritional value, shielding ability, is inexpensive & readily available which makes it excellent wall material for nanoencapsulation. These biological & functional properties can only be maintained if size and morphology of casein micelle are preserved. Hence, in the present study native casein micelles from buffalo skim milk were used as wall material for nanoencapsulation of model bioactive compound “CURCUMIN”. Modification in pH to basic & neutral sides was used as a tool to open up casein micelles for encapsulation. The encapsulation efficiency was >99 % for the final product using HPLC based method. The powder properties, analysed by reconstituting it, showed that mean particle size & zeta potential of powder solution (236 ± 14.1 nm, -19.9 ± 0.85 mV) were similar to skim milk (229± 6.38nm, -20.6 ± 0.67 mV). During gastric digestion > 90 % of encapsulated curcumin was retained (5.23 ± 1.28 % & 6.12 ± 0.24 % in wet and dried samples). In the intestinal phase as the time progressed the sample clarified indicating total breakdown of casein protein chain to peptides of smaller length (98.43 ± 1.38 & 98.12 ± 1.49 % in wet and dried samples). It can be clearly seen that most of the characteristic peaks of curcumin disappeared in the secondary derivative spectra after its NE in skim milk which is due to reduced stretching and bending of curcumin bonds due to nanoencapsulation. Blood urea nitrogen levels increased in nanoencapsulated powder treated groups as compared to paracetamol only treated group whereas creatinine, glutamate pyruvatetransaminase and alkaline phosphatase levels decreased in blood serum of mice treated with nanoencapsulated powder after/ before paracetamol treatment. Hence, curcumin was delivered successfully with high bioactivity. The nanocapsules were formed in form of a spray dried powder that is readily dispersible in dairy beverages. The product shows good encapsulation efficiency of >98 % at normal processing conditions of pH, ionic strength, sugar & temperature. This formulation is prepared using food grade additives with minimal processing & shelf stable for 6 months at ambient temperature. It could hence serve as readily dispersible powder, one serving of which has (4 g powder formulation in 200 ml milk) curcumin concentration (30-40 mg) equivalent to house hold preparation of Haldi Doodh [prepared using 500 mg haldi (equivalent to 15 mg curcumin) in 200 ml milk] and with 20% more milk proteins together with enhancement of SNF level by 18%.

142Atomic force microscopy of emulsion interfaces and their nanoparticles at the nanoscale

Lovikka Ville A.1, Chen Lin1, Figueiredo Patrícia I.1, Mikkonen Kirsi S.1,2

1Department of Food and Nutrition, P.O. Box 66, FI-00014, University of Helsinki, Finland.
2Helsinki Institute of Sustainability Science (HELSUS), P.O. Box 4, FI-00014, University of Helsinki, Finland.
Introduction
Liquid-liquid interfaces and interfacially entrapped nanoparticles have a major role in wet nanotechnology and biology. Understanding their behavior requires knowledge of their shape and mechanical properties in the nanoscale. AFM can measure the topography perfectly aligned with mechanical properties and even inflict changes in the sample for simultaneous manipulation and analysis. It can measure liquid-liquid interfaces featuring nanoparticles.[1] While the analysis of nanoparticle-stabilized emulsions, known as Pickering emulsions, have been lacking at the nanoscale,[2] we introduce an innovative AFM protocol for directly measuring real Pickering emulsion droplets and their interfacial nanoparticles at the nanoscale.[3] The behavior of the droplets and their interfacial nanoparticles is studied at varying interaction forces. Special attention is paid to nanoparticles made of lignin, an underutilized soft biomatter.

Methods
Hexadecane-in-water Pickering emulsion (PE) with soft lignin nanoparticles (LNP) or hard silica nanoparticles was prepared via rotor-stator homogenization (Ultra-Turrax) followed by ultrasonication. PE was pipetted on a polyethyleneimine-coated glass slide. After 1-15 minutes, the sample was submerged under water while avoiding strong liquid flows or menisci passing over the sample. The water was exchanged until it appeared clean. The samples were measured using a NanoWizard 4 XP BioScience AFM (Bruker) with QI™ Advanced Imaging mode. Usual setpoints (SP) were 0.05-0.35 nN and 1-12 nN for analysis and manipulation-oriented runs, respectively. If the samples were measured with alternating SPs, a more thorough understanding of their behavior was found. Chosen cantilevers (MSNL, Bruker) had nominal spring constants between 0.01-0.1 N/m which was checked with the thermal excitation method.[4] The data was turned into 3D images with Gwyddion software. The slope data from force-distance curves (stiffness) and adhesion data were overlaid on the images for enhanced visualizations.

Results
Emulsion droplets were successfully attached to the substrate and imaged with AFM in nanoresolution. At low SPs, the samples remained largely unchanged. At SPs exceeding 1 nN, fine-detailed data was lost starting from the smallest particles and eventually from large nanoparticles and the droplets. LNPs could be deformed on the interface unlike silica. Furthermore, the droplets detached from the substrate, they appeared smaller, or they lost their shape depending on, e.g., their particle coverage. Droplets in contact with each other could be merged. The adhesion was larger on the liquid-liquid interface than on the interfacial nanoparticles. The surface stiffness revealed the connectivity of the nanoparticles with their surroundings.

Discussion
AFM was highly successful at depicting the topography and mechanical properties of the Pickering droplets. The overlays and measurement repetitions at different SPs helped identify emulsion components and their connectivity. Nanoparticles and droplets were moved at high SPs. Lignin nanoparticles could be deformed on the interface suggesting that they may be sensitive to high-energy emulsification.

References
[1] Costa L., Li-Destri G., Thomson N.H., Konovalov O. & Pontoni D.; Nano Letters, 2016, 16, 5463–8.
[2] Ho T.M., Abik F. & Mikkonen K.S.; Critical Reviews in Food Science and Nutrition, 2022, 62, 4908–28.
[3] Lovikka V.A., Chen L., Figueiredo P. & Mikkonen K.S.; submitted, 2024.
[4] Butt H.-J. & Jaschke M.; Nanotechnology, 1995, 6, 1–7

149Synergistic effects of alkaline treatment and mild heating on mung bean protein isolate for enhanced plant‑based meat patty quality

Kanokrat Limpisophon1*, Xingfa Ma2, Leonard M.C. Sagis 2., Athiya Nonthakaew1, Pattariga Hirunrattana1

1Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok, 10900, Thailand.
2 Laboratory of Physics and Physical Chemistry of Food, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
*Corresponding author: Kanokrat Limpisophon
This study investigated the impact of a combined alkaline treatment (0.3 or 3.5% Na2CO3) and mild heating (40 or 70°C) on the functional properties of mung bean protein isolate (MBPI), for potential application as an emulsifier in plant-based meat patties, containing vegetable-oil emulsion droplets. The combined treatment improved MBPI's solubility (from 58 to 86%) and emulsifying properties, including its EAI (from 6.37 to 10.89 m2 g-1) and stability coefficient (38 to 96). These improvements suggest the potential for developing more stable protein-stabilized emulsions. This treatment decreased the zeta potential of the protein suspensions from −9 to −19 mV and influenced protein conformation, leading to smaller particles with higher β‑sheet content, which impacted interfacial behavior through increased hydrophobic interactions. Notably, MBPI treated with the most effective combinations (0.3% Na2CO3, 70°C and 0.3% Na2CO3, 40°C) exhibited excellent emulsifying properties, forming stable monolayers at the oil-water interface, which was probably due to the increased surface activity of MBPI as a result of Na2CO3 treatment. Increasing the protein content from 8 to 11% and the oil content from 10 to 30% further reduced emulsion droplet size, especially for MBPI treated with 0.3% Na2CO3 at 70°C (from 5.10 to 2.61 µm), likely due to decreased coalescence. For application in plant-based meat patties, the MBPI suspension prepared with MBPI treated with 0.3% Na2CO3 at 70°C, was homogenized with 30% coconut oil to obtain an emulsion. Incorporating this MBPI emulsion with texturized vegetable protein (TVP) at a weight ratio of emulsion to TVP of 2:1 (w/w) resulted in enhanced patty texture. Patties prepared from improved MBPI by combined alkaline and heat treatment exhibited lower cooking loss (14–23%) as compared to the control (18–28%), resulting in juicier patties. Additionally, these patties, when heated for the same time (20–60 sec) by microwave at 840 watts, demonstrated higher cohesiveness and springiness with lower hardness, indicating improved binding properties. These findings suggest that this synergistic treatment of MBPI has the potential to enhance the quality of plant‑based meat patties.

Keywords: Emulsion, Functional properties, Meat patty alternative, Plant-based protein

152Effects of fibrous structure of textured-vegetable-protein (TVP)-based meat analogues on the protein digestibility and absorption properties

Quanquan Lin1*, Tiantian Sun1, Mengli Sang1, Jianzhong Han1, Aiqian Ye1,2

1School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
2Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
Introduction:
In recent years, there has been a growing global interest in plant-based meat as a significant substitute for traditional meat products. Understanding the digestion and absorption characteristics of plant-based meat is of paramount importance. This study aimed to examine how the fibrous structure of textured-vegetable-protein (TVP)-based meat analogues affected protein digestibility and absorption.

Method:
A series of TVPs with different fibrous structures were prepared by changing starch contents during extrusion. The fibrous structure was evaluated by bulk density, texture, and microstructural analysis. Protein interactions in TVPs were studied using a solubility test. Their digestibility and absorption properties were assessed through an in vitro digestion test and an in vivo trial.

Results:
Structural analysis showed that an increase in starch content from 0% to 20% resulted in a decrease in the cohesiveness of rehydrated TVPs, accompanied by an initial increase followed by a decrease in hardness, springiness, and chewiness, with their peak values observed at a starch content of 10%. Furthermore, increasing starch content led to a reduction in bulk density and an increase in rehydration rate. With the incremental addition of starch increased from 0% to 15%, the fiber structure of TVPs progressively became less dense, with increased gaps between fibers. The fiber structure became disordered when the starch content further increased to 20%. The results showed that hydrogen bonds and hydrophobic interaction were enhanced with the increase in starch content. Moreover, the increase in starch content led to a reduction in the particle size of digesta of TVPs after gastrointestinal digestion, as well as an augmentation in protein hydrolysis and the release of free amino acids. The animal study showed that the variations in the starch content of TVPs did not induce a significant impact on the relative protein efficacy ratio, as well as on the apparent and true protein digestibility. Additionally, after 14 days of dietary intervention, the levels of total amino acids, essential and non-essential amino acids in the serum of rats, as well as the ratio of villus length to crypt depth in the duodenum, exhibited an initial increase followed by a decrease with increasing starch content in TVPs, reaching peak values at a starch content of 10%.

Discussion:
This study demonstrated the starch content of TVPs significantly influenced their fibrous structure and molecular interactions between proteins. The decrease in cohesiveness, the increase in fiber gaps, and the increase in exposed hydrophobic groups and hydrogen bonds synergistically promoted the access of protease to proteins, resulting in enhanced protein digestibility during in vitro digestion with higher starch content. However, findings from the animal trial indicated that the fibrous structure formed with varying starch contents in TVPs did not affect protein digestibility in vivo, but did influence the absorption of amino acids and the microscopic structure of duodenum tissue. This study demonstrated that the biological fate of TVP-based meat analogues was affected by their fibrous structure. These findings may provide valuable insights for the development of TVP-based meat analogue

167Multidimensional spectroscopy reveals the nature and intensity of polysaccharide-polyphenol interactions

Adriana M. Aguilar-Torres1, Jacopo Catalano2, Reinhard Wimmer3, Jacob J. K. Kirkensgaard4, Banny S.B. Correia1, Ivan M. Lopez-Rodulfo1, Mario M. Martinez1,5*

1Department of Food Science, Aarhus University, Aarhus, Denmark
2Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
3Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
4Department of Food Science, University of Copenhagen, Copemhaguen, Denmark
5Food Technology Division, Department of Agricultural Engineering, University of Valladolid, Valladolid, Spain
The bioactivity of polyphenols in the human body depends on the rate, extent, and location of their release in the gastrointestinal tract. Likewise, their bioactivity in extending the shelf life of foods depends on their exposure and release from the matrix polymer (e.g., matrix polysaccharides in shelf-stable films or coatings). Despite the crucial role of polysaccharide-polyphenol interactions in determining the bioactivity of polyphenol-containing foods and biomaterials, the nature and implications of these interactions remain controversial. In this study, we conducted the most comprehensive investigation of polysaccharide-polyphenol interactions to date, using a broad array of advanced spectroscopy techniques. These techniques included unidimensional (1H NMR, FTIR, 1H NMR titration) and bidimensional homonuclear spectroscopy to investigate scalar (J) spin coupling (through-bond interactions, e.g., COSY) and dipole–dipole coupling and spin relaxation (through-space interactions, e.g., NOESY, ROESY). We also examined potential polyphenol-polyphenol and starch-starch aggregation via small-angle X-ray scattering (SAXS). Additionally, the migration (depletion) of polyphenols upon washing was analyzed using LC-ESI-QTOF-MS. Starch, the main energy source in the human diet and one of the most abundant fully biodegradable biopolymers, was chosen as a model polysaccharide. To elucidate structure-function relationships, we investigated maize starch at two different amylose ratios (0 and 70% amylose) and five different polyphenols varying in the number of phenolic rings, -OH groups, and substituents (i.e., caffeic acid, cinnamic acid, gallic acid monohydrate, trans-ferulic acid, and quercetin) using the aforementioned analytical techniques. Results from FTIR, SAXS, and LC-ESI-QTOF-MS revealed that all polyphenols interact with both maize starches, showing a higher affinity for amylopectin. LC-ESI-QTOF-MS indicated that caffeic acid and trans-ferulic acid exhibited the highest binding affinity (p<0.05). Among all polyphenols, trans-ferulic acid showed a significantly higher affinity for amylopectin (p<0.05). Unidimensional and bidimensional homonuclear 1H NMR indicated that the interactions were non-covalent. Furthermore, 1H NMR titration, which was more sensitive to detecting interactions under fast exchange conditions (weak binding), confirmed that hydrogen bonds were involved in the interactions between starch and trans-ferulic acid and gallic acid. We expect that the results of this study will provide guidance for defining component blends and processing conditions to optimize polyphenol functionality in biopolymeric matrices. Additionally, this study offers a compelling analytical workflow for investigating polysaccharide-polyphenol interactions.

173Unraveling microstructure and water behavior in diverse food matrices using low-frequency NMR on proton.

Audrey Gilbert, Sylvie L. Turgeon*

Department of Food Sciences, Institute of Nutrition and Functional Foods (INAF), STELA Dairy Research Centre, Université Laval, Quebec City QC, Canada, G1V 0A6
For a couple of decades, low-frequency NMR on proton has become a method of choice to study water mobility in food matrices. It has been applied on a large spectrum of matrices, from sucrose solutions to complex hydrocolloid mixed systems. This non-destructive method gives quantitative and qualitative information about water distribution and mobility in the matrix, which can relate to matrix microstructure. Measurements of spin-spin relaxation time (T2) using Carr-Purcell-Meiboom-Gill scan sequences are often used to study hydrated matrices with long relaxation times (>1ms). Studies reported 1 to 4 water populations among which the water bounded to macromolecules (bound water), the bulk water (serum from serum), and the separated water (sedimentation, syneresis). The capacity to differentiate those populations depend on the matrices' water content and microstructure.

Experiments realized by our team on different food systems and results from the literature will be used to demonstrate how low-frequency NMR on proton can probe food microstructure in non-fat or low-fat systems. Examples range from fermented milk, mixed polysaccharides, mixed protein-polysaccharide systems (beta-lactoglobulin/xanthan gum hydrogels, fermented milk with dextran or EPS producing strains) and complex foods as legume purée. Water mobility shows similar patterns between these different matrices even though their microstructure and molecular interactions are different in nature. For instance, in yogurt formulations containing either or both fat and stabilisers the serum water mobility correlated with microstructural descriptors of network heterogeneity. The serum water often gets most of the attention in studies as it can be affected by serum solutes (ionic strength, solid content), serum viscosity, and microstructure (porosity, macromolecular density). However, water mobility has also shown its ability to detect and quantify spontaneous serum separation or detect microstructural heterogeneity due to segregative interactions.

Low-frequency NMR on proton when combined with other methods used for microstructure characterization allows to probe water interactions in both model and complex food systems. By revealing water interactions in the matrices, this non-destructive method is a powerful tool to inform on macromolecular interactions and their organization

193Structural changes and the gelling behaviour of plant proteins processed by ultrasound

Natalia Riquelme1, Paulo Díaz-Calderón2, Carla Arancibia1

1 Universidad de Santiago de Chile, Obispo Umaña 050, Estación Central, Chile.
2Universidad de los Andes, Monseñor Álvaro Del Portillo 12455, Las Condes, Chile
The global population's dietary habits are shifting towards consuming more plant-based food products, especially based on plant proteins. However, one of the main challenges of plant proteins is their lower technological functionality compared to animal ones, limiting their use in plant-based products. On the other hand, non-thermal processes, such as ultrasound and extrusion, are promising technologies to modify proteins, enhancing their techno-functional properties. In this work, different plant protein dispersions (pea, lupin, and rice) were subjected to different ultrasound times (US, 0 to 15 min) to analyze changes in their structural features (FT-IR, DSC, and microstructure by Confocal Microscopy) and gelling properties (gel strength and viscoelasticity). The FT-IR spectra showed changes in the protein secondary structure after US treatment, decreasing the relative content of ordered structures (α-helix + β-sheet) and increasing unordered structures (turn + random coil) (50%) with the increase of US time. However, this behavior was protein-dependent, where pea and lupin proteins showed larger structural changes than rice ones. Furthermore, US time led to variations in the denaturation temperature and a gradual enthalpy decrease of pea and lupin proteins (from 1.93 to 1.69 J/g and 3.10 to 1.57 J/g, respectively), indicating lower thermal stability after unfolding. The microstructure of plant proteins revealed a reduction in aggregate size (80%) as US time increased due to their hydrolysis by cavitation, except in rice proteins. On the other hand, weak gels (gel strength of 7.0 g-force) were obtained after 5 and 10 min of US in pea and lupin proteins, respectively. However, no gel formation was observed in rice protein, regardless of US treatment times. Regarding viscoelastic properties, US treatment increased gels' storage and loss moduli, indicating more structured gels at the highest US time (tan 0.3). Finally, our results suggest that ultrasound treatment can modify the structure of plant proteins, improving their gelling properties. However, this effect depends on the type of protein. Enhancing the gelation capacity of pea and lupin proteins by a US treatment can impact positively in the development of plant-based foods.

197Protein isolates made in the lab vs. the factory: a case study with mung bean and chickpea

Simon M. Loveday1,2*; Celyne Halim3

1Commonwealth Scientific and Industrial Research Organisation (CSIRO), Agriculture and Food, Werribee, VIC Australia
2Riddet Institute Centre of Research Excellence, Massey University, Palmerston North, New Zealand
3Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research
Introduction:
Protein isolates deliver functionalities such as gelling, emulsifying, and foaming, and many recent publications are reporting the functionality of new protein isolates produced in the laboratory. Laboratory protein isolation processes are quite different to industrial processes, and therefore isolate functionalities are likely to be different. We examined some of the differences between laboratory isolates and commercial isolates of mung bean and chickpea protein (MPBI and CPPI).

Method:
We tested solubility as a function of pH, dispersibility by static light scattering, and viscosity enhancement in a rapid visco analyzer (RVA). Thermal transitions were evaluated with differential scanning calorimetry (DSC), and powder morphology was examined by scanning electron microscopy (SEM).

Results:
Laboratory isolates were more soluble (e.g. 54%–57% vs. 5%–45% at pH 8) and dispersible than commercial isolates, with the largest DSC endotherms, indicating the least denaturation. Among commercial isolates, we found large differences in solubility, thermal properties, and viscosity enhancement, and minor differences in dispersibility and powder morphology. The hydration protocol had a strong effect on solubility and DSC results, and a moderate effect on RVA results. Comparisons between isolates produced in different laboratories are currently hampered by the use of nonstandard empirical methods for certain functionalities, and we highlight standardized methods for measuring dispersibility and viscosity enhancement.

Discussion:
Protein isolation processes affect isolate functionality via effects on protein denaturation and aggregation, and via the morphology and surface chemistry of isolate powders. This means that findings with laboratory isolates cannot necessarily be extrapolated to commercial counterparts, but also indicates the power of process design to modulate isolate functionality.

199Localized enzymolysis and dual-frequency ultrasound modification of underutilized fava bean protein: Techno-functional, structural, in vitro digestibility, molecular docking, and interrelationship characteristics

Abdur Rehman1, Ibrahim Khalifa1, Song Miao2, Junxia Wang1, Yongjun Zhao1, Qiufang Liang1, Mingming Zhong1, Yufan Sun1, Hafiz Ansar Rasul Suleria3, Xiaofeng Ren1,4*

1School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China.
2Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland.
3School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
4Institute of Food Physical Processing, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China.
This study examined the effect of using dual-frequency ultrasonic therapy (DFUT) and targeted enzymolysis on the physiochemical, structural, and techno-functional properties of the underutilized fava bean protein (FBP) and its hydrolysate (FBPH). FBP was enzymatically hydrolyzed (5-15% DH) to produce FBPH, employing alcalase as the catalyst. The enzymolysis process declined the color brightness, turbidity, and particle size for both non-sonicated and DFUT-treated FBP. Additionally, it increased in the absolute values of zeta potential (P < 0.05). Further, DFUT decreased water holding capacity for both FBP and FBPH compared to the untreated ones. In contrast, DFUT enhanced the oil absorption capacity compared to non-sonicated ones. Additionally, XRD, FTIR, and intrinsic fluorescence spectral analyses demonstrated that FBPH exhibited a greater degree of flexibility and mobility in its secondary structures compared to FBP. The use of diverse DH and DFUT had a significant impact on the intrinsic fluorescence, XRD pattern, secondary structure conformation, and molecular weight of all preparations. FBP and FBPH structures underwent adjustments due to the negative association between β-sheets and α-helix, as suggested by Persson's correlation. Moreover, SEM and CLSM investigations provide convincing evidence that DFUT improves and speeds up the breakdown of proteins' structures, especially at higher DH. The molecular weight of DFUT-treated FBP showed a notable decrease in the SDS-PAGE profile, but there were no discernible differences between DFUT-treated and non-sonicated FBPH. The DFUT-treated FBP-10DH had significantly better in vitro digestibility (85.70%) compared to the non-sonicated FBP-15 (76.63%) and control FBP-0DH (68.57%). This indicates that the DFUT modification effectively improved the digestibility of the hydrolysate. Correlation and molecular docking research suggest that DFUT has different impacts on specific FBP and its FBPH characteristics. Taken together, localized enzymolysis and DFUT can alter the conformation of proteins and their intermolecular interactions with FBP and FBPH, potentially enhancing their functionality and expanding their utilization in the food industry. Given the growing need for functional ingredients such as protein hydrolysate, FBPH produced through DFUT can serve as a functional ingredient in the food and pharmaceutical sectors.

Keywords: Fava bean proteins; Enzymolysis; Dual-frequency ultrasonic therapy; Sonochemically modification’s; In vitro digestibility.

200Quinoa protein fibrillation at pH 7 facilitated by bromelain hydrolysis and CaCl2 coordination

Xiao FENG (Rebecca)

College of Food Science and Engineering/Collaborative Innovation Center for Modern GrainCirculation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
Quinoa protein has high nutritional value, containing all the essential amino acids, but its weak gelling property limits its processing and application. The fibrillar aggregates of plant proteins formed at pH 2 can improve the gelling property, but the fibrils dissociate as the pH values shift. Here, we found that green enzymatic hydrolysis at pH 7 could substitute acid hydrolysis to generate thermal-induced fibrillar aggregates from quinoa protein isolate (QPI). When the enzyme to substrate ratio (E/S) increased to 0.075%, the electrostatic repulsion increased, but the hydrophobic interaction did not vary significantly, and the formation of fibrillar aggregates was favored by the synergistic effect of these two driving forces. Whereas a continuous increase in the E/S resulted in fewer fibrillar aggregates, which was due to the decreased electrostatic repulsion and enhanced hydrophobic interaction. Furthermore, when the E/S was 0.075%, the parallel β-sheet content increased and the length of fibrillar aggregates extended from 175 nm to 327 nm as the concentration of CaCl2 increased from 0 to 120 mmol/L. The unidentate coordination between Ca2+ and carboxyl groups was found for all the samples with CaCl2 addition. However, the increase of CaCl2 concentration to 160 and 200 mmol/L caused fibrillar aggregates to cluster and become shorter due to the electrostatic shielding effects, leading to the decreased gelling properties. Here, we presented an innovative method to prepare QPI fibrillar aggregates at neutral condition, and it showed limited bromelain hydrolysis and appropriate CaCl2 addition could improve the gelation of QPI by regulating its fibrillation

205Heat-induced interactions between microfluidized hemp protein particles and caseins or whey proteins

Sihan Ma, Alejandra Acevedo-Fani, Aiqian Ye, Harjinder Singh

Riddet Institute, Massey University, New Zealand
Commercial hempseed protein (HP) powder is highly aggregated and thermally unstable, but inducing their microparticulation in the presence of milk protein could potentially modify the properties of hemp protein. Therefore, comprehending the heat-induced protein-protein interactions in milk/plant protein systems is critically important. The aim of this study was to explore the interactions between hemp protein particles (HPPs) and whey protein or casein and their impact on protein aggregation during heating.

HPPs were co-heated with whey protein isolate (WPI) or sodium caseinate (NaCN) at 95 °C for 20 min to produce two types of microparticles. Static light scattering technique, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), and transmission electron microscopy (TEM) were applied to investigate the particle size, protein interactions and morphology of created microparticles.

The addition of WPI or NaCN restricted the self-aggregation of HPPs during heat treatment but through different mechanisms. SDS-PAGE indicated the formation of HPPs/WPI complexes via disulphide bonding, whereas no evidence of covalent interactions was found in HPPs/NaCN. TEM showed that both types of microparticles were spherical and of variable diameters. At the second heating cycle, HPPs/WPI microparticles exhibited good heat stability, while HPPs/NaCN microparticles were not thermally stable and formed large protein aggregates which may be because of the dissociation of NaCN during the first cooling stage.

This study shows different mechanisms for restricting heat-induced aggregation of HPPs in the presence of WPI or NaCN. The combination of plant and milk protein could be a feasible strategy for developing microparticulated protein for food applications.

206Effect of Rheology in High Moisture Extrusion of Commercial Soy Proteins

Yu Guang Leong, Yuan Xu, Peter Halley, Jason Stokes*

School of Chemical Engineering, The University of Queensland, Queensland, 4072, Australia
Extrusion of plant proteins is the most common commercial process to produce plant-based meat analogues. Despite the conceptual understanding that the rheology of plant proteins during extrusion has a significant role in affecting the operation of the extruder and the properties of the extrudate, there is a lack of study on demonstrating how rheology can be used as a tool to determine the optimal extrusion parameters for different plant proteins, and how the extrudate properties relate to the rheology of the protein suspension. Here, we study the high pressure-high temperature (HPHT) rheology of three commercial soy proteins (two isolates and one concentrate) and extrude these proteins under high moisture condition. We found that the HPHT rheology of soy protein aqueous mixtures, which is a function of their soluble and insoluble components, correlates significantly with both linear and nonlinear viscoelastic properties of extrudates. This suggests that, by varying the process temperature, solid content, and types of plant protein (exhibiting a certain temperature-dependent rheology), an extrusion process can be tuned to create plant-based meat analogue products with favoured physical properties, meanwhile achieving comparable mechanical properties to their rivals. We expect the rheology-extrusion relationship detailed here to serve as the groundwork for improving the extrusion of plant proteins in the application of meat analogues.

209Composition, physicochemical, and structural properties of black gram (Vigna mungo) proteins

Debashree Roy, Aiqian Ye, Alejandra Acevedo-Fani, Arup Nag, Harjinder Singh

Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
Introduction:
Pulses are an important source of dietary proteins in many countries and often represent a necessary supplement to other protein sources. Among pulses, black gram bean (Vigna mungo) has been recently identified as an untapped legume with unique techno-functional properties. Thus, the objective of this study was to investigate the physicochemical properties of black gram protein concentrates produced by different extraction methodologies.

Methods:
Black gram protein concentrates were produced at a pilot scale using salt-assisted and alkali-based extraction methodologies. The obtained salt-extracted (82% protein) and alkaline-extracted (76% protein) black gram protein concentrates were then analysed for protein composition, changes in physicochemical properties (such as zeta potential, isoelectric point, particle size, solubility), functional properties (foaming and emulsifying), and microstructural arrangements under different conditions.

Results and discussion:
The study revealed that black gram protein concentrates contained all essential amino acids and were abundant in vicilin type of globulin proteins (~40-50kD). The isoelectric pH was found to be around ~4.5. Changes in particle size distribution and solubility of protein dispersions indicated aggregation or dissociation as a function of pH (2-10) and ionic strength (0-1000 mM NaCl) but interestingly no visible protein coagulation was observed. The protein dispersions were found to have higher solubility in the pH range 7.5-10 (alkaline), 2-3 (acidic), and above 200 mM ionic strength, which could be explained by the nature of their electrostatic interactions under different environmental conditions. Preliminary findings showed that black gram proteins have higher foaming capacity than whey and egg white proteins and similar foam stability to whey proteins at pH 6.7. The emulsifying abilities of black gram protein concentrates were found to be dependent on the initial particle size of the dispersions and were similar to whey proteins as observed from confocal scanning microscopy. Similar trends were noted for both salt-extracted and alkaline-extracted black gram proteins. However, transmission electron microscopy revealed that the dispersions of salt-extracted black gram protein concentrates formed larger aggregates and micellar-like structures under certain experimental conditions in contrast to alkaline-extracted black gram protein concentrates, which needs to be investigated further.

Conclusion:
Overall, the study generated new scientific knowledge on the physicochemical characteristics of differently produced black gram protein concentrates. The information will be useful in developing black gram protein concentrates at an industrial scale and for their application in different dairy alternative products.

214Investigation of the gastric digestion behavior of commercial infant formulae using an in vitro dynamic infant digestion model

Faith Bernadette Descallar1, Debashree Roy1, Xin Wang1, Peter Zhu1, Aiqian Ye1, Yichao Liang2, Shikha Pundir2, Harjinder Singh1, Alejandra Acevedo-Fani1*

1Riddet Institute, Massey University, Palmerston North, New Zealand
2Fonterra Research and Development Centre, Palmerston North, New Zealand
Human milk is considered as the primary source of nutrition for growth and development, and other biological support of infants. However, when breastfeeding is not possible, infant formula is the alternative to meet the baby’s nutritional needs. Whey and casein are the two main protein constituents of human milk and infant formula. The ratio of whey to casein in human milk is about 60:40, which most of the whey-dominant commercial infant formulae adapt. However, some product specifically marketed for “hungry babies” are casein-dominant. The difference in the protein ratio is important for the digestibility of infant formula, which may affect their health. In this study, 12 different commercial infant formulae with different components and whey to casein ratios were considered to evaluate how gastric behavior affects the delivery of nutrients to the small intestine.

Each infant formula powder was reconstituted to a fixed 1.7% protein content and differing fat of 3.35-4.55%, and the digestion behaviour was investigated using an in vitro dynamic infant human gastric simulator (iHGS). Analysis of the microstructural arrangements of the protein and lipid, and colloidal stability of food during digestion were elucidated using static light scattering and confocal laser scanning microscopy to measure the particle size and confocal micrographs, respectively. The time-dependent protein hydrolysis was determined by analyzing the protein composition as a function of digestion time using sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE).

Results revealed that casein-dominant formulations had higher degree of aggregation and coalescence and formed bigger curd particles than the whey-dominant formulae. The extensive protein aggregation of casein-dominant infant formulae slowed down the hydrolysis and emptying of caseins from the iHGS. The confocal micrographs showed that oil droplets are entrapped in the curd particles of casein-dominant infant formulae, which also slowed down the gastric emptying of lipids. Additionally, the extent of coagulation was dependent on the source of protein composition. For instance, the casein-dominant goat infant formula had greater degree of aggregation, followed by sheep and cow infant formulae. Conversely, whey-dominant formulations results revealed that infant formulae with the presence of biopolymers as stabilizers increased the viscosity and induced faster flocculation. This altered the rate of protein hydrolysis and emptying of lipids. The pH profile showed that casein-dominant infant formulae have higher buffering capacity than the whey-dominant infant formulae towards the end of the digestion in the HGS. The pH highly correlated with the degree of aggregation but less on the degree of coalescence. Coalescence of fat globules is probably more influenced by the degree of hydrolysis and food matrix assembly.

This study revealed the great impact that protein composition and presence of other components, such as biopolymers, may have on gastric structuring and retention of nutrients in the infant stomach. This information is meaningful for the further development of structurally advanced infant formulae with specific nutritional needs.

215Impact of Extraction Processes and Cell Wall Structure on Crude Protein Digestibility of Macroalgal and Microalgal Proteins

Lirong Chenga, Alice Maoa, Harjinder Singha, Lee Huffmanb, Jacky Zhub, Tom Wheelerc Arup Naga*

aRiddet Institute, Massey University, Palmerston North 4474, New Zealand
bThe New Zealand Institute for Plant and Food Research Ltd, Palmerston North 4442, New Zealand
c Food and Bioactives Group, Cawthron Institute, Nelson 7010, New Zealand
Corresponding author: Dr. Arup Nag A.Nag@massey.ac.nz
This study has investigated the impact of the microstructure of algal biomass and extracted algal protein on crude protein digestibility. Two algae, Pyropia seriata (macroalgae) and Chlorella vulgaris (microalgae), were selected for their distinct differences in cell wall structure and polysaccharides. An in vitro dynamic human gastric simulation (HGS) digestion model was employed, integrated with in vitro static oral and small intestinal models to simulate the human upper digestive tract and peptide absorption.

The microstructure of the algal biomass and protein extracts before and during digestion was examined using confocal laser scanning microscopy. Protein solubility, degradation, and digestibility were quantified using SDS-PAGE and the Kjeldahl method. The study revealed that the cell wall structures of Pyropia seriata and Chlorella vulgaris were sensitive to gastric acidification, releasing proteins at pH 3, thereby allowing digestive enzymes to access macronutrients for hydrolysis. This led to crude protein digestibility values of 76% for Pyropia seriata and 89% for Chlorella vulgaris, comparable to the 78% for commercial pea protein concentrate.

Notably, disruption of the cell structures of protein extracts from Pyropia seriata enhanced protein digestion, increasing crude protein digestibility from 76% to 96%. Conversely, cell disruption of Chlorella vulgaris decreased its digestibility from 89% to 68%, likely due to reduced enzyme accessibility caused by heat-induced protein aggregation arising from pasteurization and spray drying processes.

The crude protein digestibility assessments from the in vitro dynamic digestion model were well-aligned with the Digestible Indispensable Amino Acid Score (DIAAS) determined by an in vivo rat model. These findings offer valuable insights into the modifications of algal biomass and protein microstructures during upper gastrointestinal digestion and validate the use of in vitro models for determining protein nutritional quality. This knowledge supports the potential use of algal biomass and proteins as novel protein sources in future food development.

227In vitro digestion and fermentation characteristics of eight kinds of pulses and suggestions for different populations

Haihua Ji, Yadong Zhong, Ziyi Zhang, Yu Chen, Yanli Zhang, Shuigen Bian, Junyi Yin, Jielun Hu, Shaoping Nie

State Key Laboratory of Food Science and Resources, China-Canada Joint Lab of Food Science and Technology (Nanchang), Key Laboratory of Bioactive Polysaccharides of Jiangxi Province, Nanchang University, 235 Nanjing East Road, Nanchang 330047, China
Introduction: Pulse-based diets are attracting attention for their potential in combating diet-related non-communicable diseases. However, limited research studies have focused on the digestive and fermentative properties of pulses, which are crucial for exerting benefits.

Method: In vitro digestion. In vitro fermentation. Analysis of short-chain fatty acids (SCFAs). Analysis of gut microbiota.

Results: The findings indicated that pulse flours and pastes were low GL food (estimated GL < 10) and had a low degree of protein hydrolysis during simulated gastrointestinal digestion. During in vitro fermentation, pulses flours and pastes decreased the fermentation pH, increased the level of short-chain fatty acids (mainly consisting of valeric acid, followed by acetic acid, propionic acid, butyric acid, isobutyric acid, and isovaleric acid), and positively modulated the microbiota composition over time, specifically reducing the ratio of Firmicutes to Bacteroidetes. In addition, we found that boiling could affect the in vitro digestion and fermentation characteristics of pulses, possibly depending on their intrinsic nutrient characteristics.

Discussion: Nutritional properties of eight kinds of pulses were assessed by simulating in vitro digestion and fermentation in this study. Cooking treatment showed various changes on the characteristics of in vitro digestion and fermentation of pulses, which could be due to variations in structural properties, as well as the microstructure and composition of the pulses. Guided by factor analysis, for different individuals under intaking pulses, cowpea, broad bean, white lentil, and white kidney bean were preferred for diabetic individuals, yellow pea and white lentil were preferred for intestinal homeostasis disorders, white lentil, broad bean, white kidney bean, and cowpea were suitable for obese individuals, in which white lentils was considered healthier and suggested for healthy adults.

230Effect of modified β-lactoglobulin on the stability of algae oil emulsion: storage, environmental and oxidative stability

Wei Tanga,b, Rui Wanga,b, Weilin Liuc, Jianfei Hea,b*, Jianhua Liua,b*

a College of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310014, P. R. China
b Whole Grain Nutritious Food Processing Technology Research and Experimental Base of Ministry of Agriculture and Rural Affairs, Zhejiang University of Technology, Hangzhou, 310014, P. R. China
c School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, P. R. China
Abstract: Using modified protein as an excellent emulsifier for emulsion has become a research hotspot in recent years. The purpose of this study was to improve the stability of algae oil emulsion by using modified β-lactoglobulin (β-Lg) as the excellent emulsifier. The β-Lg was modified through glycation with konjac oligo-glucomannan under optimized time of 48 h (G48β-Lg). Then, the glycated β-Lg was treated by high pressure microfluidization (HPM) at 80 MPa (HG48β-Lg), and further grafted with (-)-epigallocatechin-3-gallate (EGCG) to form the emulsifier (EHG48β-Lg) for stabilizing algae oil emulsion. The algae oil emulsion was characterized by particle size, zeta potential, microstructure and rheology. The interfacial properties of algae oil emulsion were evaluated by interfacial layer thickness and interfacial tension. The stability of algae oil emulsion was comprehensively evaluated by storage, temperature, ionic strength, pH and accelerated oxidation treatment. It was found that after glycation reaction, β-Lg formed a thicker interface layer on the surface of the oil droplets, which had a lower surface tension and could better protect the algae oil from the effects of temperature, ion concentration and pH. In addition, after HPM treatment and EGCG grafting, the antioxidant activity of algae oil emulsion was significantly enhanced due to the expansion of the protein and the grafting of more hydroxylated EGCG. Conclusively, the modification by glycation, HPM treatment and EGCG grafting can make β-Lg become the potential emulsifier that can effectively improve the stability of algae oil emulsions.

Keywords: emulsion, β-lactoglobulin, algae oil, EGCG, high pressure microfluidization,

231Effect of soybean processing by products (Okara) incorporation on the physicochemical properties and in vitro digestion behavior of tofu gel

Qi Meng1, Christos Ritzoulis1,2, Ruijie Wang1, Weiping Jin1, Jianzhong Han1, Weilin Liu1, *

1 School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, PR China
2 Department of Food Science and Technology, International Hellenic University, Alexander Campus, 57400, Thessaloniki, Greece
The incorporation of Okara, a high-fiber soybean processing by product, in tofu can effectively increase the utilization of soybean residue and improve the nutritional value of tofu. In this study, the effects of Okara volume ratio on the physicochemical properties and in vitro semi-dynamic digestion behavior of tofu gel formulated by different coagulants (CaCl2/GDL) were investigated. The results showed that the texture of tofu gel was significantly (P > 0.05) affected by the Okara addition, with 15% Okara in GDL tofu and 2.5% Okara in CaCl2 tofu having highest hardness. The water holding capacity and moisture content of GDL-Okara tofu and CaCl2-Okara tofu showed increasing and then decreasing trends as okara content increased. FTIR results exhibited that the secondary structure of the tofu protein changed at Okara present, with higher content of α-helix and β-sheet. SEM images displayed tofu had most homogeneous and densest gel network and least pores when Okara was 15% in GDL tofu and 2.5% in CaCl2 tofu, respectively. The following in vitro semi-dynamic digestion behavior showed that 2.5% Okara addition retarded the CaCl2 tofu degradation, with smaller changes in particle size, less total amino acids accumulation and microstructure damaged when compared to the tofu gel without Okara addition. This study provided a comprehensive understanding of the gelling and digestion properties of GDL/CaCl2 Okara-tofu.

Keywords: Okara, Tofu, Texture, Coagulants, in vitro semi-dynamic digestion

235Utilizing capillary forces to structure protein oleogels:

Annika Feichtinger, Elke Scholten*

Physics and Physical Chemistry of Foods, Wageningen University, The Netherlands
The ongoing protein transition puts high pressure on the food industry to reformulate their food products into plant-based analogues. Next to plant proteins, also the fat source needs to be plant-based. In many of these products, exotic fats, such as palm oil and shea butter are used, due to their solid character. However, there are several concerns related to deforestation and other sustainable aspects connected to the use of such fats. Alternatives for solid fats are thus desired. A novel category that would increase ingredient flexibility are protein oleogels, in which proteins are used to provide a solid structure to liquid plant oils, such as sunflower, rape seed or olive oil. In such approach, different types of proteins, including whey, soy, pea or potato, are introduced in oil via an intermediate solvent approach, after which a small amount is added to create a protein network. The water forms smaller water bridges between proteins, also known as capillary bridges. Capillary bridge formation is a powerful approach to modify the rheological properties of such oleogels. The small amount of water provides an attractive capillary force to induce protein particle network formation, which increases the gel strength by orders of magnitudes. The network, and the corresponding rheological characteristics, such as gel strength, critical strain, and recoverability, largely depend on the properties of the particles. In the case of protein particles, there is a large variation in their properties, such as the ability to absorb water and swell, the roughness of the particles, particle size, and their internal network, depending on the conditions used to create such protein particles. Little is known about how variations in particle properties affect particle interactions and capillary bridge formation. In this research, we systematically varied these properties to gain more understanding on the particle network formation. By imaging of spherical protein particles of relatively large size (up to 20 μm), we show that even though particles are able to absorb water, enough water was available to form bridges and increase the network strength. In this presentation, we further discuss the specific effects of particle properties such as size, water absorption capacity and surface roughness on capillary suspension rheology. We demonstrate how modification of protein particle properties provide ample opportunities to control the rheological properties of the protein oleogels. In addition, we also discuss how different heat treatments facilitates further network rearrangements, and therefore also alter specific rheological properties.

schematic showing capillary suspention

253Texture, microstructure, and in vitro digestion of hybrid meat analogues formulated with functionalized pea protein

Yunqing Nie1, Youling L. Xiong1,2*, and Jiang Jiang1

1 State Key Laboratory of Food Science and Resources, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
2Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, 40546, USA
Hybrid meat analogues offer an alternative strategy to incorporate plant proteins as a partial substitution for traditional meat formulations, addressing consumer preference as well as the rising environmental and health concerns. However, the low gelling ability of plant protein compared to meat protein presents a challenge for producing a smooth texture and water binding in hybrid meat products. Understanding the molecular interaction of proteins, hydrocolloids, salt, and other ingredients in the mixed system as well as protein digestion is crucial to the success of hybrid meat. The objective of the study is to investigate the complex formulation effects (plant-based ingredients, hydrocolloids, salt levels, etc.) on the textural and microstructural properties of prototype hybrid meat products, and to compare their oxidation stability and in vitro digestion behavior.

Plant-based ingredients, including functionalized pea protein isolate by ultrasonication (UPPI, 30% w/v) and pea flour, were used to substitute lean meat at three levels (ratios 100:0, 75:25, and 50:50). UPPI-based emulsion containing 30% (w/v) canola oil was filled into the hybrid matrix to form emulsion sausages (final 4.5% oil). The salt levels were 0.3 M and 0.6 M NaCl to simulate low- and high-salt product conditions. Fermented celery powder was added as natural nitrite-curing agent. Rheological properties, physical characteristics, microstructure, oxidative stability, and in vitro digestibility of hybrid sausages were examined.

Protein cross-linking was not detected in the pea-meat hybrids. Cooked hybrid emulsion sausages showed a slightly pink cured color, but the chromatic a* value decreased 15–45% with pea protein substitution after cooking. Nonetheless, the lightness (L*) did not change. The hardness and breaking force of hybrid sausages decreased with increasing the substitution ratio, while cohesiveness and deformability were comparable to those of control (no substitution). Consistently, hybrid sausages had a uniform and dense distribution of protein and fat. Moreover, pea protein substitution restricted bulk water mobility (revealed by 1H-NMR) and substantially reduced cooking loss (25–70%, P < 0.05) when compared with all-meat control. Yet, cooked hybrid sausages were susceptible to lipid oxidation during refrigerated storage (TBARS elevated to 2.5 mg malonaldehyde/kg in 14 days) suggesting the necessity for antioxidant protection. In simulated in vitro digestion (1 h pepsin then 2 h pancreatin), approximately 90–95% protein in hybrid sausage was hydrolyzed into short peptides and amino acids, leaving several 15–20 kDa oligopeptides as the remnants

In conclusion, this study demonstrated the potential of using functionalized pea protein substitute and other plant-based ingredients to create hybrid meat sausages with modulated textural properties, rheology, and digestibility, offering a promising approach to the development of sustainable meat alternatives

204In vitro gastric digestion of pea protein using a human stomach simulator: effects of heat treatment

Dan Li a, b, Alejandra Acevedo-Fani b, Ying Ma a, Weihong Lu a, Harjinder Singhb, Aiqian Ye b, *

aSchool of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
bRiddet Institute, Massey University, Private Bag 11 222, Palmerston North, 4442, New Zealand
* Corresponding author: Aiqian Ye, a.m.ye@massey.ac.nz
Introduction Plant proteins have become increasingly desirable due to their sustainability and proposed health benefits. Understanding the behaviour of plant proteins during gastric digestion is crucial for understanding the protein delivery and protein digestibility. This study assessed the physicochemical and structural changes in pea protein (PP) after heat treatment at various temperature and pH values, and how these changes influence the in vitro gastric digestion behaviours in the context of a human gastric simulator.

Methods: The PP samples were adjusted to various pH levels (7.8, 6.8, 6.5, 6.0, 5.5), then heated at different temperatures (60°C, 70°C, 80°C, 90°C, 95°C) for 20 min. The study evaluated the protein solubility, physical stability, microstructure, particle size and ζ-potential of PP solutions. Furthermore, the gastric digestion behaviour of PP and heated PP was investigated using an in vitro dynamic human gastric simulator, respectively. The microstructural changes, physicochemical stability, and protein digestibility were examined using CLSM, dynamic light scattering, and SDS-PAGE.

Results: The particle size of PP decreased after heating at pH 7.8, 6.8 and 6.5, but it increased after heating at pH 6.0 and 5.5. The extent of change was dependent on temperature and time. Solubility increased with heating at pH values of 7.8, 6.8, and 6.5, but decreased with heating at pH 6.0 and 5.5. SDS-PAGE showed that no disulfide bonds were formed in the PP aggregates induced by heating. During dynamic gastric digestion, both PP and heated PP did not undergo extensive aggregation throughout the digestion process, in which the particle size of the heated PP was smaller compared to that of PP. Additionally, the protein hydrolysis rate of the heated PP samples by pepsin was higher than that of PP, which might be due to the decrease in the particle size (increase in surface area of particles) of PP aggregates after heat treatment, which might have increased the accessibility to pepsin.

Conclusion: Heat treatment under certain conditions improved the solubility and decreased the particle size of PP aggregates. Furthermore, heating promoted the digestibility of PP in the stomach. This study explores how heating affects the gastric digestion of PP, highlighting their stability and structural behavior, which could impact nutrient delivery to the next digestion stage.

212Temperature-induced Release of Salt from Double Water-in-Oil-in Water Emulsion Made with Coconut Oil.

Nur Farra Adlina Mohamed Zakhari1, Nur Suaidah Mohd Isa1*, Faridah Yahya1, Nor Hayati Ibrahim1, Kostas Gkatzionis3, Hani el-Kadri2

1 Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia (Corresponding institution)
2 School of Chemical Engineering, University of Birmingham, Edgbaston, United Kingdom.
3Department of Food Science and Nutrition, School of the Environment, University of the Aegean, Lemnos, Greece
Non-communicable diseases (NCD) have been associated with high-salt intake which led to proactive action by the government and industry in obtaining the best strategy for salt reduction in foods. Some of the proposed strategies such as the modulation of salt crystal size and inhomogeneous distribution of salt may not be suitable for high moisture foods due to the water solubility of salt while the incorporation of salt in oil-in-water (O/W) emulsion does not ensure the targeted delivery of salt. Thus, the compartmentalization approach by using water-in-oil-in-water (W1/O/W2) was proposed in this study to elevate saltiness perception by delivering salt to the taste buds and released in ‘bursts’. The controlled release of salt can be achieved through the phase transition of coconut oil with change in temperature (room temperature to body temperature). In this study, emulsion samples were prepared by using a two-step homogenization process at 1:1 ratio of single emulsion (W1/O) to external aqueous phase (W2). The double emulsion was composed of inner aqueous phase (W1) with various concentration of NaCl ranging from 0% to 0.60% w/v, an oil phase that consists of coconut oil with 1.5% w/v of PGPR and the W2 phase that consists of distilled water with 1% w/v of Tween 80. Droplet stability, thermal properties, rheological properties and the release of NaCl from W1/O/W2 emulsions were investigated with change in temperatures and during storage. In addition, the effects of double emulsion on the saltiness perception were also evaluated in model salad dressings through sensory evaluation. Double emulsion prepared with higher salt concentration was found to be most stable with change in temperatures and during 4 weeks of storage whereby significant change (p<0.05) was only observed after 2 weeks of storage in terms of droplet size measurement, viscosity as well as creaming index. The rheological analysis of samples showed a pseudoplastic behavior whereby an increase in viscosity was evident with the increase in salt concentration. Moreover, significant increase (p<0.05) in the percentage of salt released was observed as the temperature increased to 37 and 40°C. In addition, the melting point of samples containing salt were in the range of 25±1°C as compared to samples without salt (23°C). Photomicrographs showed extensive droplet destabilization and increase in the fluorescence intensity of the W2 phase with change in temperature. Sensory analysis through ascending force choice revealed the significant increase (p<0.05) in saltiness perception for W1/O/W2 samples as compared to W1/O. The results obtained indicated that the controlled release of salt from coconut oil-based double emulsions can be achieved with change in temperature due to extensive droplets destabilization whereby this system can potentially be used in the development of low salt food products

185Physicochemical properties of hybrid cheddar cheese gels made from cow-milk and plant protein isolates

Md Abid Hasan Sarker1, Christopher Pillidge1, Jayani Chandrapala1, Roya Afshari2, Harsharn Gill1*

1 School of Science, STEM College, RMIT University, Melbourne, VIC 3083, Australia
2CSIRO Food Innovation Centre, 671 Sneydes Rd, Werribee, VIC 3030, Australia
Plant-based proteins are becoming increasingly popular substitutes for animal-based proteins in food applications. Although plant-based proteins are more environmentally friendly and cheaper to produce, alternatives to animal-protein food products (e.g. vegan meats and cheese) made from plant proteins have limited market value due to generally inferior taste and texture properties. A more useful approach is to combine plant proteins in blended products. Cheese, one of the most frequently consumed protein-rich foods, is an ideal candidate for incorporating plant-based proteins into an animal-based protein gel matrix. Nonetheless, there is presently only limited understanding of the scientific properties of hybrid plant-animal protein gels. Such knowledge is essential to underpin new product development and market opportunities.

In this study, cow milk-plant hybrid cheddar cheese gels were prepared in small-scale cheese vats using a standard mesophilic cheese starter and cheesemaking conditions. Up to 40% of the dairy protein was replaced with plant protein isolates derived from soy, pea, and faba bean.

Key scientific properties of these gels were determined, including gel viscosity, rheology, gel microstructure, changes in protein secondary structures, and particle-size distribution of cheese milk. Colour and moisture content, gel firmness, whey protein percentages and composition and SDS protein-gel profiles were also determined

Initial data showed that incorporating plant proteins increased the average particle size in the cheese milk and its viscosity and reduced the resulting gel strength. FTIR analysis showed changes in spectra in regions corresponding to protein functional groups, indicating the different protein-protein interactions and structural changes. Further detailed results, including gelation kinetics and milk and gel microstructure of gels made from cow milk alone and cow-milk with soy, pea or faba protein, and the corresponding cheesemaking yields, will be presented.

Understanding the cheese gel properties while incorporating plant proteins will underpin the development of hybrid cheeses, which will meet evolving consumer preferences and ensure more sustainable cheese production.

Keywords: Cheddar cheese gel, plant proteins, techno-functional properties, sustainability

195Texturization of Plant-Based Products: Strengthening Pea Protein Gels with Collagen and Enzymatic Crosslinking

Parisa Eslami, Victoria Haritos, Leonie van ‘t Hag

Department of Chemical and Biological Engineering, Monash University, Clayton, VIC, 3800, Australia
The growing interest in plant-based proteins is driven by increasing awareness of health benefits, population growth, freshwater scarcity, and climate change (Pojić et al., 2018; Sá et al., 2020). However, controlling their structural and textural characteristics is still a challenge, leading to extensive research into modifying the properties of plant gels to enhance their textural quality. Among plant-based proteins, pea proteins are particularly promising due to their high quality, well-balanced amino acid profile, and low allergenicity (Schlangen et al., 2023)

In this work, an approach for improving the gelling ability of low-concentration pea protein isolate (PPI) and collagen mixture was investigated. An enzymatic crosslinking agent, transglutaminase (TG), was employed to enhance the gel strength of the mixture. Rheological oscillatory time sweep analysis demonstrated an approximately 100-fold enhancement in gel strength of the PPI (50 mg/mL) and collagen (3 mg/mL) mixture at moderate temperature (≤ 50 ℃) compared to PPI alone, when treated with TG. The presence of a three-dimensional gel network was confirmed using scanning electron microscopy (SEM), while texture analyser confirmed the improved gel strength, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) indicated the successful crosslinking within the protein matrix

The results of this study provide an innovative approach in the development of stronger gels for plant-based products, offering possibilities for making formulations of better-quality products that would be more appealing to consumers. From these technical improvements, this research also offers a promising solution for protein supply in global food industry

References
1Pojić, M., Mišan, A., & Tiwari, B. (2018). Eco-innovative technologies for extraction of proteins for human consumption from renewable protein sources of plant origin. Trends in Food Science & Technology, 75, 93-104.
2Sá, A. G. A., Moreno, Y. M. F., & Carciofi, B. A. M. (2020). Plant proteins as high-quality nutritional source for human diet. Trends in Food Science & Technology, 97, 170-184. https://doi.org/10.1016/j.tifs.2020.01.011
3Schlangen, M., Ribberink, M. A., Taghian Dinani, S., Sagis, L. M. C., & van der Goot, A. J. (2023). Mechanical and rheological effects of transglutaminase treatment on dense plant protein blends. Food Hydrocolloids, 136. https://doi.org/10.1016/j.foodhyd.2022.108261