Stability and Digestive Properties of a Dual-Protein Emulsion System Based on Soy Protein Isolate and Whey Protein Isolate

Research on the preparation of soy protein isolate and whey protein isolate composite nanoparticles and their characteristics in high internal phase Pickering emulsions

This study investigated the role of thermal drive in the formation of soy protein isolate and whey protein isolate (SPI-WPI) complexes, as well as the stability effect of SPI-WPI complexes on high internal phase Pickering emulsions (HIPPEs). The shift in the peaks in the infrared spectrum and the change in fluorescence intensity indicated the interaction between these two proteins, which implies that SPI-WPI is not two dispersed groups of particles. Maximum emulsification activity (10.65 m2/g) and the absolute value of potential (37.87 mV) were achieved at an SPI to WPI mass ratio of 7:3. As the concentration and pH of the SPI-WPI complex increased, the droplets become evenly uniform and compact. It is predicted that the high concentration conditions are more favorable for the formation of a gel network structure. This research provides an effective strategy for HIPPEs stabilization using complex proteins.

Effects of different saccharides glycosylation modified soy protein isolate on its structure and film-forming characteristics

With the serious impact of traditional plastic packaging on the environment, the development of safe, environmentally friendly and degradable packaging materials has become a research hotspot. Glycosylation reaction has been explored by researchers because of its green, efficient and simple. In this study, the film-forming properties of soy protein isolate (SPI) were improved by glycosylation modification. Different types of saccharides (monosaccharides: glucose, fructose, xylose; oligosaccharides: maltose, fructooligosaccharide, xylooligosaccharide; polysaccharide: gum arabic) were introduced into the SPI by moist heat method. The results show that the xylose-modified SPI film has the best performance in mechanical properties and thermal stability, and its tensile strength is increased to 5.1 MPa, and its elongation reached 117.8 %. Structural analysis revealed that glycosylation resulted in a decrease in α-helix content of SPI, while β-sheets and random coils increased, forming a tighter cross-linked network, improving film density and stability. Furthermore, xylose modification significantly reduced the water vapor transmission rate to only 12.64 g/m2·24 h. These modifications significantly enhance the comprehensive properties of SPI films, especially in terms of thermal stability and moisture barrier properties. The correlation analysis between SPI film properties and internal structure shows that glycosylation can change the internal structure of protein and further affect the film properties. The research in this paper provides a theoretical basis for the glycosylation modification of SPI, and provides a new idea for the sustainable development of food packaging materials.

Dual-protein system composed of soy protein and β-lactoglobulin: effect of transglutaminase-mediated crosslinking on its allergenicity and conformation

BACKGROUND

The escalating global prevalence of food allergies has intensified the need for hypoallergenic food products. Transglutaminase (TGase)-mediated crosslinking has garnered significant attention for its potential to reduce the allergenicity of food proteins. This study aimed to investigate the effects of TGase crosslinking on the potential allergenicity and conformational changes in a dual-protein system composed of β-lactoglobulin (β-LG) and soy protein isolate (SPI) at varying mass ratios (10:0, 7:3, 5:5, 3:7 and 0:10 (w/w)).

RESULTS

TGase preferentially crosslinked the 7S and 11S subunits of soy protein, rather than β-LG. Crosslinking treatment reduced the allergenic potential of both soy protein and β-LG, with the degree of reduction depending on the protein ratio. The β-LG5:SPI5 and β-LG7:SPI3 mixtures showed the most significant reduction in antibody reactivity towards soy protein and β-LG, respectively. Additionally, TGase-mediated crosslinking significantly reduced the binding capacity of all dual-protein samples to serum immunoglobulin E from allergic patients, compared to the control group (P < 0.05). The allergenicity reduction was accompanied by structural modifications, including a decrease in β-sheet content, an increase in β-turn and random coil structures, enhanced ultraviolet absorption and intrinsic fluorescence, reduced free sulfhydryl levels and altered intermolecular forces. These changes suggest that TGase-induced crosslinking may disrupt or mask allergenic epitopes, thus lowering allergenicity.

CONCLUSION

TGase crosslinking effectively reduced the allergenic potential of the dual-protein system by inducing structural changes. These findings underscore the potential of TGase in developing hypoallergenic dual-protein food products and provide a scientific foundation for future research and application in the food industry. © 2025 Society of Chemical Industry.

(E,E)-2,4-decadienal improved the stability of gelatin emulsion manufactured by low-energy stirring emulsification

The study investigated the impact of varying concentrations of (E,E)-2,4-dodecenal (DDE; 0, 9, 27, 54, and 81 μg/mL) on the stability of gelatin emulsions prepared via a low-energy stirring emulsification method, which relies solely on simple mechanical stirring. As the concentration of DDE increased, the particle size, emulsifying activity index, emulsion stability index, and viscosity of emulsions first increased significantly (P < 0.05) and then decreased significantly (P < 0.05), indicating that the emulsion stability first improved and then decreased. The highest emulsion stability was observed at a DDE concentration of 27 μg/mL, as evidenced by the highest adsorbed protein content (84.78 %) and the maximum absolute zeta potential value (14.46 mV). These findings suggested that DDE, in combination with low-energy stirring emulsification, improved the stability of gelatin emulsions. The results of protein structure indicated that DDE enhanced the depolymerization of gelatin by disrupting hydrophobic interactions within gelatin aggregates, leading to the exposure of hydrophobic groups on the protein surface. This exposure enhanced the adsorption of gelatin at the oil-water interface, thereby improving the emulsion stability through increased steric hindrance at the interface. Furthermore, DDE reduced the interfacial tension of soybean oil, contributing to further stabilization of the interface.

Effects of mixing ratio on physicochemical, structural properties and application in lycopene-loaded emulsions of blends of whey protein and pea protein

Physicochemical, structural properties and application in lycopene-loaded emulsions of blends of whey protein isolate (WPI) and pea protein isolate (PPI) at varying mass ratios (100/0, 75/25, 50/50, 25/75, 0/100) were investigated. Data indicated that the mass ratios affected the physical, chemical and storage stability of the emulsion by influencing the particle size, zeta-potential, surface hydrophobicity, free sulfhydryl content, and secondary structure of the blends. Particularly, emulsion with a mixing ratio of 75/25 exhibited superior physical stability against salt concentrations (200 and 500 mM), better chemical stability against UV light and heat, and maintained stability over a 30-day storage period. Emulsions stabilized by blends of different ratios exhibited similar digestion behavior, with no significant differences observed in lycopene's transformation stability and bio-accessibility. Data indicated that substitution of whey protein by pea protein is effective in term of emulsifier application and replacement ratio is an important factor need to be considered.

Effect of Whey Protein Isolate and Soy Protein Isolate on Textural Properties and Syneresis of Frozen Traditional Chinese Hot Pot Egg Sausage Gels

Egg sausages, an essential component of traditional Chinese hot pot cuisine, have specific storage requirements and are predominantly distributed through refrigerated channels. A significant consideration in the freezing of egg sausages pertains to syneresis and textural modifications that manifest in the protein gel structure upon thawing. This research investigated the efficacy of incorporating whey protein isolate, soy protein isolate (at concentrations of 0.5%, 1.0%, and 2.0%), and modified cassava starch (at concentrations of 1.0%, 2.0%, and 3.0%) to enhance the textural integrity and mitigate syneresis in frozen egg sausage gels. The research demonstrated that syneresis in frozen egg sausages could be significantly minimized from 9.01% to 1.16% through the incorporation of 3% modified cassava starch and 2% whey protein isolate, to 2.01% with 1.0% soy protein isolate, and to 3.05% with 1.0% whey protein isolate. Furthermore, the combination of modified cassava starch (3%) and whey protein isolate (2%) demonstrated enhanced textural characteristics in frozen egg sausages with 20% additional water content following a 15-day storage period. Notably, egg sausages formulated with 0.5% whey protein isolate exhibited superior sensory attributes, including springiness, texture, and overall acceptability, compared to other formulations. The incorporation of whey protein isolate yielded markedly improved sensory characteristics relative to soy protein isolate additions. The findings indicate that the incorporation of whey protein isolate (0.5-1.0%) in conjunction with modified cassava starch (3%) effectively improves textural properties while reducing syneresis in thawed egg sausages.

Improved qualities of cod-rice dual-protein gel as affected by rice protein: Insight into molecular flexibility, protein interaction and gel properties

Blending plant-based proteins with animal-based proteins to achieve adequate dietary protein intake is a strategy to address dietary deficiencies in the elderly. This research systematically investigated the effect of the ratio of cod protein/rice protein (21:0, 21:1.5, 21:3, 21:4.5, 21:6, 21:7.5, and 21:9) on the gelation properties of dual-protein gels and the underlying dual-protein interaction mechanisms. The results indicated that the myosin heavy chain (MHC) of cod and the glutelin in rice protein are primarily linked by hydrogen bonds, particularly involving Tyr residues, as evidenced by molecular docking and fluorescence quenching results. The addition of rice protein in cod protein promoted α-helix transforming into β-sheet, β-turn and random coil of the original protein solution, which was significantly correlated with molecule flexibility increasing. The decrease in the dual-protein particle size, and rice protein uniformly distributed in a cod protein-based gel network, which promoted the compactness and density of the gel structure. It was found that the hardness and springiness of 21:6 cod-rice protein gel increased by 73.96% and 17.28% compared to single cod gel, respectively. This study provides theoretical basis to the mechanism of dual-protein interaction affecting gel properties from the molecular level.

Advancements in emulsion systems for specialized infant formulas: Research process and formulation proposals for optimizing bioavailability of nutraceuticals

With the rapid advancements in nutrition and dietary management, infant formulas for special medical purposes (IFSMPs) have been developed to cater to the unique nutraceutical requirements of infants with specific medical conditions or physiological features. However, there are various challenges in effectively preserving and maximizing the health benefits of the specific nutraceuticals incorporated in IFSMPs. This review provides an overview of the nutritional compositions of various IFSMPs and highlights the challenges associated with the effective supplementation of specific nutraceuticals for infants. In addition, it emphasizes the promising potential of emulsion delivery systems, which possess both encapsulation and delivery features, to significantly improve the solubility, stability, oral acceptance, and bioavailability (BA) of nutraceutical bioactives. Based on this information, this work proposes detailed strategies for designing and developing model IFSMP emulsions to enhance the BA of specially required nutraceuticals. Key areas covered include emulsion stabilization, selective release mechanisms, and effective absorption of nutraceuticals. By following these proposals, researchers and industry professionals can design and optimize emulsion-based IFSMPs with enhanced health benefits. This review not only outlines the developmental states of IFSMP formulations but also identifies future research directions aimed at improving the physiological health benefits of IFSMPs. This effort lays the theoretical groundwork for the further development of emulsion-type IFSMP in infant formula (IF) industry, positioning the IF industry to better meet the complex needs of infants requiring specialized nutrition.

Composite-structure oleogels constructed by glycerol monolaurate and whey protein isolate: Preparation, characterization and in vitro digestion

The Glycerol monolaurate (GML) oleogel was induced using Camellia oil by slowly raising the temp to the melting point (MP) of GML. Whey protein isolate (WPI) solution with different ratios was composited with GML oleogel by emulsion template methods, forming dense spines and honeycomb-like networks and impressed with an adjustable composite structure. Textural results showed that compared with single GML-based oleogels, the GML/WPI composite oleogels had the advantages of high hardness and molding, and structural stability. The composite oleogels had moderate thermal stability and maximal oil binding (96.36%). In particular, as up to 6 wt% GML/WPI, its modulus apparent viscosity was significantly increased in rheology and similar to commercial fats. Moreover, it achieved the highest release of FFA (64.07%) and the synergy provided a lipase substrate and reduced the body's burden. The resulting composite oleogel also showed intermolecular hydrogen bonding and van der Waals force interactions. These findings further enlarge the application in the plant and animal-based combined of fat substitutes, delivery of bioactive molecules, etc., with the desired physical and functional properties according to different proportions.

Development of Oleogel-in-Water High Internal Phase Emulsions with Improved Physicochemical Stability and Their Application in Mayonnaise

Egg-free mayonnaise is receiving greater attention due to its potential health benefits. This study used whey protein isolate (WPI) as an emulsifier to develop high internal phase emulsions (HIPEs) based on beeswax (BW) oleogels through a simple one-step method. The effects of WPI, NaCl and sucrose on the physicochemical properties of HIPEs were investigated. A novel simulated mayonnaise was then prepared and characterized. Microstructural observation revealed that WPI enveloped oil droplets at the interface, forming a typical O/W emulsion. Increase in WPI content led to significantly enhanced stability of HIPEs, and HIPEs with 5% WPI had the smallest particle size (11.9 ± 0.18 μm). With the increase in NaCl concentration, particle size was increased and ζ-potential was decreased. Higher sucrose content led to reduced particle size and ζ-potential, and slightly improved stability. Rheological tests indicated solid-like properties and shear-thinning behaviors in all HIPEs. The addition of WPI and sucrose improved the structures and viscosity of HIPEs. Simulated mayonnaises (WE-0.3%, WE-1% and YE) were then prepared based on the above HIPEs. Compared to commercial mayonnaises, the mayonnaises based on HIPEs exhibited higher viscoelastic modulus and similar tribological characteristics, indicating the potential application feasibility of oleogel-based HIPEs in mayonnaise. These findings provided insights into the development of novel and healthier mayonnaise alternatives.

The Synergistic Effect of Compound Sugar with Different Glycemic Indices Combined with Creatine on Exercise-Related Fatigue in Mice

In this study, a compound sugar (CS) with different glycemic index sugars was formulated via hydrolysis characteristics and postprandial glycemic response, and the impact of CS and creatine emulsion on exercise-related fatigue in mice was investigated. Thirty-five C57BL/6 mice were randomly divided into five groups to supply different emulsions for 4 weeks: initial emulsion (Con), glucose emulsion (62 mg/10 g MW glucose; Glu), CS emulsion (62 mg/10 g MW compound sugar; CS), creatine emulsion (6 mg/10 g MW creatine; Cr), and CS and creatine emulsion (62 mg/10 g MW compound sugar, 6 mg/10 g MW creatine, CS-Cr). Then, the exhaustion time of weight-bearing swimming and forelimb grip strength were measured to evaluate the exercise capacity of mice, and some fatigue-related biochemical indexes of blood were determined. The results demonstrated that the ingestion of CS significantly reduced the peak of postprandial blood glucose levels and prolonged the energy supply of mice compared to ingesting an equal amount of glucose. Mouse exhaustion time was 1.22-fold longer in the CS group than in the glucose group. Additionally, the supplementation of CS increased the liver glycogen content and total antioxidant capacity of mice. Moreover, the combined supplementation of CS and creatine increased relative forelimb grip strength and decreased blood creatine kinase activity. The findings suggested that the intake of CS could enhance exercise capacity, and the combined supplementation of CS and creatine has a synergistic effect in improving performance.

Evaluation of sono-physico-chemical and processing effects in the mixed sarcoplasmic protein/soy protein isolate system

Since it may be employed to guide the production of high-quality plant protein as a partial substitute for animal protein using sono-physico-chemical effects, it is important to investigate the mixing of animal and plant protein in ultrasound (UID)-assisted processing systems. A study group of sono-physico-chemical processing with five distinct soy protein isolate (SPI)/ sarcoplasmic protein (SPN) ratios was developed in this work. The results showed that adding additional SPN to the mixed protein can increase its sono-physico-chemical impact, and this effect is greatest when the ratio of SPI to SPN is 1:3. The high SPN group's grafting rate rose from 39.13% to 55.26% in comparison to the high SPI content group. Quercetin (Que) may more readily modify SPN than SPI in the "dual protein" system used in this work, highlighting the critical function of plant protein in controlling the effects of UID-assisted processing in the "dual protein" system. Changes in apparent viscosity and microstructure are the primary parameters that affect the severity of sono-physico-chemical effects in SPI/SPN mixed protein systems, in addition to structural variables.