The interaction between anionic polysaccharides and legume protein and their influence mechanism on emulsion stability

Developing thickened soy protein-based liquid systems: Importance of oil-water interfacial behavior

Rheological properties are critical in the design of dysphagia foods. Interfacial behavior is a critical factor in determining the rheological properties of emulsions. In this study, dysphagia foods were prepared by thickening soy protein-based liquid systems with xanthan gum, guar gum, and pectin. Interfacial behavior in dysphagia foods was focused on using interfacial dilatational rheology and quartz crystal microbalance with dissipation technique. The results showed that xanthan gum/soy protein and pectin/soy protein composite particles exhibited higher dynamic interfacial tension than soy protein particles. The results were opposite for guar gum/soy protein composite particles. Moreover, the thickness and mass of the interfacial layers formed by XG/SP and GG/SP were greater than that of P/SP, with the most stable interfacial microstructure formed by XG/SP. This study reveals the correlation between the physical properties and interfacial behavior of dysphagic foods and provides insights for the development of novel dysphagic foods.

Effect of fatty acid chain length on physicochemical properties and structural characteristics of high-moisture meat analogues based on soy-hemp-wheat protein

Lipids are a crucial factor affecting the quality of meat analogues (MAs). However, there have been no reports on the study of fatty acid (FA) chain length in MAs. Therefore, this study evaluated the effects of different chain length FAs (lauric acid, myristic acid, and stearic acid) on the quality and structure of soy protein isolate (SPI), hemp protein (HP), and wheat gluten (WG) extrudates through methods such as texture, LF-NMR, and SEM. Compared with the control group, as the FA chain length decreased, the hardness and chewiness gradually decreased, and the elasticity gradually increased, especially the lauric acid elasticity increased from 92.51 % to 96.87 %. Compared with the other two FAs, lauric acid enhanced the hydration ability of the extrudate and promoted the formation of intermolecular hydrogen bonds. Overall, the longer the FA chain length, the less it affects the texture and the greater its impact on the fiber structure.

Characterization of the effects of insoluble soybean polysaccharides on the formation and physicochemical properties of soybean isolate protein gel

The effects of insoluble soybean polysaccharides (ISPS) on the formation and physicochemical properties of soybean protein isolate (SPI) gel were studied. As ISPS concentration increased, SPI suspensions showed reduced surface hydrophobicity and zeta-potential and enhanced thermal stability. However, the zeta-potential increased after gel formation. The ISPS decreased the hardness of the 6 % SPI gel, which could be attributed to the fact that ISPS reduced the elasticity of gel network, making the microstructure loose and porous and behaving as a weak gel; however, for the 10 % SPI gel, the ISPS promoted the increase in hardness and exhibited a weaker negative impact on the textural and microstructural properties of SPI gel. Results revealed that ISPS could react with SPI via non-covalent bonds and embedded into the protein network, weakening or strengthening the structure and texture of SPI gel and this impact is related to the mass ratio between these two biopolymers.

Gastrointestinal pH-sensitive Pickering emulsions stabilized by glycosylated zein conjugates ferulic acid nanoparticles: Improving oral bioaccessibility of Coenzyme Q10

Pickering emulsion stabilized by food grade nanoparticles with stimulus response as a targeted delivery system for lipophilic bioactive compounds has attracted people's attention. In this study, ferulic acid was used to modify saccharified zein to prepare pH-sensitive nanoparticles for stabilizing Pickering emulsion. The structure, interface behavior, stability of Pickering emulsion and gastrointestinal digestion characteristics of nanoparticles in vitro were studied. The results showed that covalent embedding of ferulic acid (ZGF-con) effectively improved the surface properties of zein nanoparticles based on glycosylation modification of zein, further regulating their behavior at the oil-water interface. In addition, the particle size of ZGF-con was small (92.93 nm), the wettability was moderate (89.85 °), and it was spherical, with orderly transition of secondary structure, which was conducive to the formation of stable emulsion at the oil-water interface. The stable Pickering emulsion formed by ZGF-con showed ideal emulsification performance, and the electrostatic repulsion between droplets and the formation of a robust spatial network structure promoted the stability of the emulsion. In addition, the encapsulation efficiency of CoQ10 in ZGF-con stabilized Pickering emulsion reached 96.11 %. In vitro simulated digestion, ZGF-con stabilized Pickering emulsion was relatively stable in the gastric acid environment, and slowly released in the small intestine, realizing the small intestine targeted release of CoQ10, which increased its bioaccessibility from 10.57 % to 56.42 %. This study provides an effective strategy for the preparation of pH-sensitive Pickering emulsion to improve the bioaccessibility of hydrophobic active ingredients.

Physicochemical and rheological characterization of plant-based proteins, pectin, and chitin nanofibers for developing high internal phase Pickering emulsions as potential fat alternatives

This study evaluated the properties of lentil protein, pea protein, quinoa protein, and soy protein as natural nanoparticle stabilizers and their interactions with pectin and chitin nanofiber in preparing high internal phase Pickering emulsions (HIPPEs). The globular plant proteins interact with polysaccharides through hydrogen bonding and electrostatic interactions, transforming the structure into complex morphologies, including fibrous and elliptical shapes. These complex nanoparticles exhibited enhanced thermal decomposition stability, and the HIPPEs constructed by them demonstrated significantly improved apparent viscosity and elastic modulus, with a yield stress of 931.9 Pa, showing gel-like viscoelastic characteristics. The complex system not only reduced droplet size but also formed a compact network structure, which enabled the emulsion to maintain excellent stability under heat treatment, long-term storage and high-speed centrifugation. Our findings revealed the promising potential of utilizing plant-based proteins with polysaccharides to prepare HIPPEs for developing fat alternatives.

Study on structure, properties and formation mechanism of cassava starch-faba bean protein heat-induced gel

In this experiment, the effects of different concentrations of cassava starch (CS) on the gel behavior of faba bean protein (FBP) were studied, focusing on the structural characteristics, gel characteristics and physical and chemical characteristics of the gel system. Specifically, with the increase of CS concentration from 4 % to 12 %, the morphology of the sample changed from fluid to gel solid. From the molecular structure, different concentrations of CS affected the secondary and tertiary structures of FBP protein, which made aromatic amino acids move to the surface of protein and promoted the transformation from α-helix to β-sheet. In addition, free sulfhydryl groups are converted into disulfide bonds, which increases the number of hydrogen bonds in the system. Microscopically, high temperature treatment leads to the cracking of CS and FBP structures, which enhances the noncovalent interactions between them, and forms a compact and smaller pore three-dimensional network structure, providing more channels for external moisture to transfer to the inside. From the gel characteristics, the water holding capacity, viscoelasticity and mechanical behavior of the composite gel were improved when the concentration of CS was 6 %-12 %. This work provides reference for the application of cassava starch-faba bean protein gel in specific food and medicine fields.

Soy protein-gellan gum noncovalent complexes stabilized emulsion: Effect of heating and pH on emulsion stability

This paper investigated the effects of heating and pH on the stability of emulsions of non-covalent complexes of gellan gum (GG) and soy protein isolate (SPI). As a result, the GG-SPI complexes stabilized emulsion exhibited a minimum emulsion particle size (945 ± 23 nm), a maximum absolute values of zeta-potential (-32.7 ± 0.81 mV), the highest values of emulsion activity index (EAI) and stability index (ESI) (132 ± 4.7 min) when emulsion was prepared under the following conditions: oil phase ratio of 18 %, polysaccharide-protein proportion of 1:8 (w/w), homogeneous pressure at 80 MPa and homogeneous time at 4 min. GG-SPI emulsion had the best emulsification performance at pH 9.0 and 75 °C owing to the protein defolding occurred, the content of α-Helix increased, hydrophobic groups were exposed, and the number of negative groups on the surface of proteins increased under the high pH and high temperature conditions. The experimental results revealed the key role of heating and pH treatment for protein emulsion stability regulation, which will enrich the application of gellan gum in soy protein emulsions and provide an important theoretical basis for the future application of emulsion modification.

Enhancing emulsification properties of pea protein isolate: Impact of heat treatment and soy hull polysaccharides on conformational modification and stability

In order to investigate the effect of conformational change in pea protein isolate (PPI) on its emulsification properties, soy hull polysaccharides (SHP) were added to modify the conformation following heat treatment at 70-100 °C to improve emulsification. The results of UV and fluorescence spectroscopy indicated that the heat treatment exposed the amino acid residues to a more hydrophobic environment. The mean volume diameter (d4,3) of PPI was reduced from 67.25 ± 3.31 to 45.50 ± 0.62 μm, and secondary structure of protein became more ordered. The addition of SHP enhanced the adsorption of protein at the oil-water interface and reduced the interfacial tension. Interestingly, SHP decreased the short-term (12h) thermal stability index (TSI) from 3.5 to 2.8 in PPI/SHP emulsion treated at 100 °C. These findings validated that heat treatment combined with SHP modification can improve the emulsification of PPI, which positively impacts the development of pea-based products for high temperatures applications.

Effect of ultrasound intervention timing on the formation mechanism and emulsifying properties of chickpea protein isolate-citrus pectin complexes

This study systematically investigated the effects of ultrasonic treatment timing on the formation and emulsifying properties of chickpea protein isolate (CPI) and citrus pectin (CP) complexes. Results showed that introducing ultrasound during the CPI pre-treatment stage significantly enhanced the emulsifying activity and stability of the complexes. Notably, compared with the independent CPI, the emulsifying activity index of CPIU-CP soared from 0.14 m2/g to 0.26 m2/g, while the emulsion stability index increased dramatically from 41.5 % to 95.5 %. Mechanistic studies revealed that ultrasonic treatment disrupted the protein structure of CPI, increasing its surface hydrophobicity and charge, thereby enhancing electrostatic interactions and steric hindrance effects with CP. Consequently, the interfacial properties of the complex were improved, leading to enhanced emulsifying performance. This study provides a novel approach to utilize ultrasound technology to regulate the structure and function of protein-polysaccharide complexes.

Recent advances in fucoidan-based improved delivery systems: Structure, carrier types and biomedical applications

Consumer demand for nutritional supplements has fueled the rapid growth of the functional food market. However, ensuring the stability of functional factors in harsh environments remains a major challenge. The development of encapsulation systems is regarded as an effective method for enhancing the stability of functional factors, encapsulation carriers can offer protection for these functional factors. However, the selection of materials remains a significant constraint in the construction of delivery systems. Therefore, developing new encapsulation materials is crucial for advancing delivery systems, preserving the stability of functional factors, and ensuring public health. Fucoidan, a sulfated marine polysaccharide, has garnered significant attention in the field of encapsulation due to its notable advantages, including its remarkable bioactivity, biocompatibility, and targeted binding properties. Fucoidan-improved delivery systems provide new strategies for encapsulation of functional factors. This review first describes the structure of fucoidan, its modification and lists the applications of modified fucoidan, and assesses its feasibility for enhancing delivery systems. Second, it summarizes several common encapsulation technologies and methods, and outlines various carrier types based on fucoidan. Finally, it elucidates recent advances in the biomedical applications of fucoidan-improved delivery systems. Notably, it also presents the challenges and future prospects of this promising field.

(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.

Edible insect protein concentrates: Optimized salt-assisted extraction methods evaluation

This study explores the extraction of proteins from edible insects such as Tenebrio molitor, Acheta domesticus, and Locusta migratoria using alkaline extraction and acid precipitation (AEAP) as a control method and evaluates the influence of salting-in (NaCl-assisted), salting-out ((NH₄)₂SO₄), and combined salting-in/out techniques on the resulting protein quality and functional properties. We hypothesized that salt-assisted methods would enhance protein extraction efficiency and functionality compared to AEAP. Molecular size distribution analysis confirmed that the salting-out method preferentially aggregated smaller proteins (<30 kDa). FT-IR spectroscopy revealed notable changes in protein secondary structure across extraction methods, while amino acid profiling identified 17 amino acids, with essential amino acids (EAAs) comprising 37.8-44.2 % of total amino acids. Salt-assisted methods significantly increased the zeta potential (up to -62.67 mV) and modulated particle size distribution (180-492 nm) compared to the control samples. Rheological properties varied with extraction techniques, with potential fluid-type transitions. Proteins extracted via salt-assisted methods demonstrated high purity (>70 %), enhanced solubility (>60 % at pH 7.4), improved oil- and water-holding capacities (1.40-8.09 g/g, 2.41-4.4 g/g), and superior emulsifying properties (EAI >47 m2 g-1, ESI >50 %). These findings highlight that salt-assisted extraction methods can improve the quality and functionality of insect protein concentrates, supporting their potential for food-grade applications.

Rice bran protein O/W emulsion enhanced by microfluidization and gum arabic: Physicochemical property, environmental stability, oxidation kinetic

In order to solve the problem of wastage of rice bran resources and make full use of the rice bran protein (RBP) with high nutrition, an oil-in-water (O/W) emulsion was successfully prepared from RBP by dynamic high pressure microjet technology (DHPM) assisted with gum arabic (GA), which provided an effective method for fully exploiting RBP resources. The results indicated that, the emulsion treated under 120 MPa exhibited superior properties. The dispersion of the emulsion droplets was more uniform, the zeta potential was -24.88 ± 0.65 mV, and the emulsion stability index showed a notable increase of 10.80 %. Besides, the rheological properties of the emulsion were improved, demonstrating good viscoelasticity. The oxidation kinetics model was set up by using the emulsion treated with 120 MPa pressure. The equation obtained was c=12865.44e-3123.518T∗t+0.49, which could be utilized to predict the oxidation of rice oil in the emulsion system. This study provided effective support for the processing and utilization of RBP products.

Enhancing 3D food printing precision: Development and interaction behavior of soy protein isolate-konjac glucomannan-xanthan gum composite ink based on hot-melt extrusion

In the field of 3D printing, the physicochemical properties of composite inks are pivotal for constructing accurate printing networks. However, the precise fabrication of molded simulants using food 3D printing technology remains a challenging endeavor. The molecular structure and rheological properties of soybean protein isolate (SPI) make it prone to fracture under high shear stress, compromising printing accuracy and stability. This study aimed to address the deficiencies in precision and stability of existing soy protein-based inks for plant-based meats by developing a food composite ink system that incorporated SPI, konjac glucomannan (KGM), and xanthan gum (XG). The new ink system was designed to capitalize on the interactions between proteins and polysaccharides, as well as the synergistic effects of polysaccharides, to achieve high printing precision and the potential for simulant preparation. The addition of KGM and XG to the ink formulation enhanced the shear-thinning behavior, which was more amenable to the printing process, compared to the control group consisting of SPI alone. The SK1X1 composite ink demonstrated a significant improvement in printing precision by 40 % and in printing stability by 59 %, with final values reaching 99.11 % and 98.51 %, respectively. Additionally, hydrogen bonding was identified as a predominant factor in the gel network structure of SPI-KGM-XG composite inks. The self-assembling behavior of KGM-XG with SPI resulted in a robust spatial network structure, which in turn enhanced the thermal stability of the ink. In conclusion, the SPI-KGM-XG blends were determined to be suitable for use as thermo-extruded edible inks, and the synergistic effect of KGM-XG bolstered the gel properties of the hybrid inks, positioning them as ideal candidates for application in the 3D printing of meat simulants.

Enhanced physicochemical properties and riboflavin delivery ability of soy isolate protein/sugar beet pectin composite freeze-dried gels prepared by double crosslinking strategy

Improving the mechanical strength of protein freeze-dried gels materials has become a research priority in the field of nutrient delivery system development in recent years. In this study, double crosslinking freeze-dried gels were prepared by integrating laccase catalyzed sugar beet pectin (SBP) as a highly active filler molecule into the soybean isolate protein (SPI) thermally induced gel network, followed by freeze-drying. The double crosslinking freeze-dried gels were a porous material and the addition of SBP resulted in the formation of amorphous forms of freeze-dried gels with lower binding energy. The freeze-dried gels with 2.0 % SBP addition had the densest microstructure with the highest density (19.00 mg/cm3) and mechanical strength (180.43 ± 15.27 KPa), and hydrogen bonding, NH, CN, and CO bands were the most important factors to maintain the freeze-dried gels structure. As the concentration of sugar beet pectin increased, the release mechanism of riboflavin underwent a shift from a Fickian to a non-Fickian diffusion mechanism. In addition, the highest bioavailability of riboflavin was found in the freeze-dried gels spiked with 2.0 % SBP. These results will contribute to the development of double crosslinking freeze-dried gels carriers for targeted slow release of hydrophilic bioactive.

Thermal stability of γ-PGA modified fish gelatin emulsion

BACKGROUND

Emulsions are thermally unstable systems. This research aimed to investigate the thermal stability of fish gelatin (FG) oil-in-water emulsions in the presence of poly-γ-glutamic acid (γ-PGA) as an additive after heat treatment. The study assessed how γ-PGA influences the thermal stability of FG emulsions over time, focusing on their properties, structure, and food application potential.

RESULTS

The incorporation of γ-PGA significantly enhanced the thermal stability of FG emulsions, preserving their morphology after heating. Emulsions containing 0.1% γ-PGA showed no significant changes after 24 h at 90 °C, while emulsions without γ-PGA experienced noticeable delamination. Rheological evaluations revealed that the energy storage modulus and loss modulus of FG-γ-PGA emulsions remained consistently higher than those of FG emulsions, regardless of heating duration. Particle size analysis indicated minimal changes for FG-γ-PGA emulsions (413 nm after 24 h) compared to a substantial increase for FG emulsions (1598 nm). After heating, FG-γ-PGA emulsions demonstrated significantly higher emulsifying activity index (EAI) (74 m2 g-1 versus 22.7 m2 g-1) and emulsifying stability index (ESI) (97% versus 76%). Additionally, the texture properties of meat mince formulated with FG-γ-PGA emulsions were comparable to those containing fat, showcasing their potential as a fat replacement.

CONCLUSION

The study concludes that γ-PGA enhances the thermal stability of FG emulsions, maintaining their integrity and improving functional properties under heat treatment. These findings offer valuable insights for the formulation of thermally stable emulsions, presenting promising opportunities for innovative applications in the food industry. © 2024 Society of Chemical Industry.

Hyaluronic acid promotes heat-induced gelation of ginkgo seed proteins

This study aimed to investigate how varying concentrations (0.01-0.5 %, w/v) and molecular weights (50, 500, 1500 kDa) of hyaluronic acid (HA) affect the physicochemical properties of heat-induced ginkgo seed protein isolate (GSPI)-HA composite gel. Incorporating HA increased viscosity (up to 14 times) and charge (up to 23 %) of GSPI-HA aggregates, while reducing particle size (up to 31 %) and improving gel texture, particularly with high molecular weight HA. However, high concentrations (0.5 %, w/v) of HA weakened gel texture. Non-covalent bonds primarily drive the formation of a continuous gel network between HA and GSPI, resulting in small pores and enhanced hydration properties. With increasing HA molecular weight, non-covalent interactions between GSPI and HA increased, leading to improved gel thermal stability. Overall, the study suggests that manipulating the molecular weight and concentration of HA can enhance the gelling properties of GSPI, leading to the development of a diverse array of GSPI-HA composite gels with varied properties.

Recent advances in the plant protein-polyphenol interactions for the stabilization of emulsions

Proteins from plant sources including legumes, cereals and oilseeds are gaining attention due to their suitability for sustainable production, functionality, and positive consumer perception. On the other hand, polyphenols (PPs) are receiving considerable attention as natural ingredients in the human diet due to their potent antioxidant and anti-inflammatory properties. Recent studies indicate that the emulsifying properties of plant proteins (PLPs) can be improved after modification through covalent and/or non-covalent interactions with PPs due to the changes in the conformation and/or the surface chemistry of the proteins. Complexes formed between PLPs-PPs can serve as innovative ingredients for developing novel food products with modified textural properties. Also, Pickering emulsions, multiple emulsions, multilayer emulsions, nanoemulsions, and high internal phase emulsions can be stabilized by such systems to deliver bioactive compounds. This paper reviews the most recent research on the PLP-PP interactions and their role in the stabilization of various emulsion-based systems. A special emphasis is given to modifying the structure and functionality of PLPs and PPs. The challenges and opportunities of applying PLP-PP interactions in emulsion-based systems are also highlighted.

Preparation and properties of β-carotene-loaded sanxan emulsion gel microcapsules

Sanxan has important application value in the field of bioactive substance delivery. However, the current sanxan emulsion gel method has certain limitations in delivering heat-sensitive lipophilic bioactive substances. In this study, the acid-gelling properties of sanxan were utilized to prepare sanxan emulsion gel microcapsules (SEGMs) by extrusion dripping method. The sanxan Pickering emulsion had a particle size of 298.4 nm and an absolute ζ-potential of 48.6 mV, exhibiting better stability. As the concentration of sanxan increased from 0.5 % to 0.9 %, the hardness of SEGMs prepared with gluconolactone as the fixing solution increased by 104.1 %. SEM results showed that oil droplets in the emulsion gels were uniformly distributed in the network of sanxan gels, resulting in smooth and dense wavy structures. Moreover, the porosity of SEGMs could be adjusted by the concentration of sanxan and the oil phase fraction jointly. The in vitro digestion simulation test indicated that SEGMs had a protective effect on β-carotene in simulated gastric fluid, with a release rate of 0.56 %. In simulated intestinal fluid, SEGMs slowly released β-carotene with a release rate of 66.20 %. The results of this study provide theoretical support for the use of sanxan-based emulsion gels or oleogels as lipophilic nutrient delivery systems.

Enhancement of soy protein functionality by conjugation or complexation with polysaccharides or polyphenols: A review

Soy proteins have good nutritional quality and exhibit a range of useful functional attributes, making them a viable option for replacing animal proteins in the development of more sustainable and eco-friendly plant-based food products. Nevertheless, soy proteins are prone to denaturation and/or aggregation under conditions they encounter in some food and beverage products (including certain pH, ionic, and thermal conditions), which adversely impact their functional performance. This problem can often be overcome by covalently (conjugation) or noncovalently (complexation) linking the soy proteins to polysaccharides or polyphenols, thereby expanding their application scope. Compared to soy proteins alone, these conjugates or complexes exhibit enhanced technofunctional performance, including improved solubility, emulsification, foaming, gelling, antimicrobial properties, and antioxidant capacities. Conjugates are typically more stable than complexes, which may be an advantage for some food applications. However, complexes do not require additional regulatory approval, which makes them more suitable for most food applications. This review aims to comprehensively examine the enhancement of soy protein functionality through conjugation or complexation with polysaccharides or polyphenols. The research focuses on how these modifications enhance solubility, emulsification potential, foaming, gelling, and antioxidant properties, reduce the allergenicity of soy proteins, and enable their potential applications in plant-based food development, 3D food printing, fat substitutes, functional food carriers, and hypoallergenic foods.

Physical modification of vegetable protein by extrusion and regulation mechanism of polysaccharide on the unique functional properties of extruded vegetable protein: a review

Development and utilization of high quality vegetable protein resources has become a hotspot. Food extrusion as a key technology can efficiently utilize vegetable protein. By changing the extrusion conditions, vegetable protein can obtain unique functional properties, which can meet the different needs of food processing. However, extrusion of single vegetable protein also exposes many disadvantages, such as low degree functional properties, poor quality stability and lower tissue fibrosis. Therefore, addition of polysaccharide has become a new development trend to compensate for the shortcomings of extruded vegetable protein. The unique functional properties of vegetable protein-polysaccharide conjugates (Maillard reaction products) can be achieved after extrusion due to regulation of polysaccharides and adjustment of extrusion parameters. However, the physicochemical changes caused by the intermolecular interactions between protein and polysaccharide during extrusion are complex, so control of these changes is still challenging, and further studies are needed. This review summarizes extrusion modification of vegetable proteins or polysaccharides. Next, the effect of different types of polysaccharides on vegetable proteins and its regulation mechanism during extrusion is mainly introduced, including the extrusion of starch polysaccharide-vegetable protein, and non-starch polysaccharide-vegetable protein. Finally, it also outlines the development perspectives of extruded vegetable protein-polysaccharide.

Mechanism of sucrose improving the mechanical characteristics of foams stabilized by soy protein isolate/gellan gum/guar gum ternary complex

Sucrose shows the potential of stabilizing foam system. This study systematically evaluated the mechanism by which sucrose improved foaming properties and mechanical characteristics of foams stabilized by soy protein isolate/gellan gum/guar gum ternary complex. Results showed that sucrose could bond to the surface of ternary complex or self-aggregate within the continuous phase, resulting in the neutralization of charges (nearly zero) and an increase in particle size (up to 62.54 μm). The addition of 30 % sucrose reinforced foam system with an increased foamability (305.99 %) but a longer foaming time (10 min) during foaming process. Moreover, the mechanical characteristics, including hardness, elastic strength (Power-law constant) and solid characteristic (frequency exponent), were also significantly enhanced to 1.26 N, 354.7956 and 2.5873, respectively, which were 1.65, 1.94 and 1.11 times than those of foams without sucrose. The microscopic mechanism lied in the reduced water freedom degree caused by sucrose, which generated a compact structural network around bubbles for providing a stable and stiff structure to foams. These findings will provide clear theoretical guidance for regulating mechanical characteristics of aerated foods by using sucrose as structural building blocks.

Study of the mechanism of non-covalent interactions between chlorogenic acid and soy protein isolate: Multi-spectroscopic, in vitro, and computational docking analyses

This study investigated the interaction mechanism between chlorogenic acid (CA) and soy protein isolate (SPI) through multi-spectroscopic and computational docking and analyzed the changes in its functional properties. The results showed that the interaction of CA with SPI changed its UV and fluorescence absorption, and the fluorescence quenching mechanism was static quenching. At the same time, the secondary structure of the protein was altered, with a reduction in α-helix, β-sheet and β-turn. Computer docking analysis showed that CA binds to SPI through hydrophobic interactions, van der Waals forces, and hydrogen bonding to form a more compact complex. In addition, the dose-dependent enhancement of CA improved the functional properties of the complexes, including foaming, emulsification, and antioxidant properties. This study systematically investigated the mechanism of interaction between CA and SPI, which supports further research on food complex systems containing CA and SPI, as well as the application of the complex.

Structural and functional properties of polysaccharides extracted from three Dioscorea species

Dioscorea has a history spanning over 2000 years for both medicinal and edible purposes in China. It contains rich polysaccharides, which are frequently utilized as thickening and stabilizing agents in the food industry. However, there has been relatively little focus on polysaccharides from common Dioscorea species besides D. opposita, such as D. alata and D. esculenta. In this study, non-starch crude polysaccharides were isolated from D. opposita (BD), D. alata (WC), and D. esculenta (GZ). Their structures, physicochemical compositions, and functional properties were characterized and compared. The results indicated three polysaccharides all exhibited characteristic peaks of polysaccharides and possessed triple-helix structures. The Glc (36.78-83.90 %), Man (6.71-26.68 %), and GalA (8.54-10.22 %) were identified as the primary monosaccharide components. In terms of functionality, three polysaccharide solutions demonstrated non-Newtonian flow characteristics and displayed commendable thermal stability. It is worth noting that the antioxidant and emulsifying properties of polysaccharides isolated from D. opposita (BD) and D. alata (WC) were superior to those of D. esculenta (GZ), making them more suitable for use as antioxidants and stabilizers. By comparing polysaccharides derived from different Dioscorea species, this study provides valuable insights into the food, cosmetic, and pharmaceutical industries based on the unique properties of these different polysaccharides.

Effects of molecular weight of hydrolysate on the formation of soy protein isolate hydrolysate nanofibrils: Kinetics, structures, and interactions

Enzymatic hydrolysis prior to protein fibrillation was an effective way to facilitate the formation of nanofibrils. This study aimed to investigate the effects of molecular weights of hydrolysate on the kinetics, structures, and interactions of soy protein isolate (SPI) hydrolysate nanofibrils. The results showed that hydrolysate with molecular weight > 10 kDa showed a distinct fibrillation kinetics curve and a higher apparent rate constant (27.72) during fibrillation, indicating their vital role in determining the fibrillation. Hydrolysate with molecular weight > 10 kDa could form nanofibrils with higher radius gyration (17.11 ± 0.77 Å) due to stronger hydrophobic interaction, showing a stronger fibrillation ability. Hydrolysate with molecular weight within 5-10 kDa exhibited enhanced π-π stacking interactions during fibrillation, thereby promoting the extension of nanofibrils, and contributing to the formation of more nanofibrils. Hydrolysate with molecular weight < 5 kDa tended to randomly aggregate during fibrillation, resulting in a significant loss of cross-β structures in nanofibrils. Therefore, hydrolysate with different molecular weights exhibited synergistic effects during fibrillation.

Comparative study of Maillard reaction and blending between soybean protein isolate and soluble soybean polysaccharide: Physicochemical, structure and functional properties

Soybean protein isolate-soluble soybean polysaccharide (SPI-SSPS) complexes and mixtures with varying SPI/SSPS concentration ratios (1: 1, 2:1, 4:1, 8:1) were prepared by Maillard reaction and blending, respectively, and their physicochemical, structure, and functional properties were compared studied. The physical stability of SPI-SSPS complex, which consisted of CN and CS bonds, was better than that of the SPI/SSPS mixture with electrostatic interactions and hydrogen bonds, and both were superior SPI alone. The complex with SPI/SSPS concentration ratio of 8:1 had the highest grafting degree (33.25 %) and a more ordered structure, making its solubility and emulsifying property lower than the SPI/SSPS mixture; however, the physical and thermal stability of the SPI-SSPS complex was higher than that of the SPI and SPI/SSPS mixture. In particular, the SPI-SSPS complex with a high grafting degree showed a higher thermal denaturation temperature (194.06 °C). This study aimed to provide effective modification methods to utilize soybean processing by-products by modifying soybean protein isolate with soluble soybean polysaccharide.

Insight into low methoxyl pectin enhancing thermal stability and intestinal delivery efficiency of algal oil nanoemulsions

BACKGROUND

Algae oil has garnered widespread acclaim due as a result of its high purity of docosahexaenoic acid (DHA) and excellent safety profile. The present study aimed to develop stable nanoemulsions (NEs) systems containing DHA from algae oil through thermal sterilization by combining modified whey protein concentrate (WPC) with low methoxyl pectin (LMP), as well as to investigate the impact of LMP concentration on the thermal stability and the gastrointestinal delivery efficiency of DHA NEs.

RESULTS

The addition of LMP enhanced the stability of the emulsion after sterilization, at the same time as improving the protective and sustained release effects of DHA in the gastrointestinal tract. Optimal effect was achieved at a LMP concentration of 1% (10 g kg-1 sample), the stability of the emulsion after centrifugation increased by 17.21 ± 5.65% compared to the group without LMP, and the loss of DHA after sterilization decreased by only 0.92 ± 0.09%. Furthermore, the addition of 1% LMP resulted in a substantial reduction in the release of fatty acids from the NEs after gastrointestinal digestion simulation, achieving the desired sustained-release effect. However, excessive addition of 2% (20 g kg-1 sample) LMP negatively impacted all aspects of the NEs system, primarily because of the occurrence of depletion effects.

CONCLUSION

The construction of the LMP/WPC-NEs system is conducive to the protection of DHA in algae oil and its sustained-release in the gastrointestinal tract. The results of the present study can provide reference guidance for the application of algae oil NEs in the food field. © 2024 Society of Chemical Industry.

Encapsulation of lycopene in Pickering emulsion stabilized by complexes of whey protein isolate fibrils and sodium alginate: Physicochemical property, structural characterization and in vitro digestion property

In present study, whey protein isolate fibrils and sodium alginate complexes (WPIFs-SA) were prepared and further used to stabilize Pickering emulsions for lycopene delivery. The optimal interaction between WPIFs and SA occurred at pH 3.0, with a mass ratio of 2:1. Increasing the oil fractions and the content of WPIFs-SA complexes significantly improved Pickering emulsions' stability, concurrently reducing droplet size and increasing viscoelasticity. Meanwhile, it facilitated the formation of a thicker protective layer and a compact network structure around the oil droplets, offering better protection for lycopene against thermal and photo degradation. In vitro digestion studies revealed that as the oil fractions and complex contents increased, the lipolysis degree decreased. The engineered WPIFs-SA Pickering emulsion could be used as an innovative delivery system for the protection and delivery of lycopene.

Synergistic effect of gellan gum and guar gum on improving the foaming properties of soy protein isolate-based complexes: Interaction mechanism and interfacial behavior

Interactions among multi-component play a critical role in modulating the foaming properties of aerated foods. This study evaluated the mechanisms of synergistic improvement of gellan gum (GEG) and guar gum (GUG) on the foaming properties of soy protein isolate (SPI)-based complex. The results showed that the GEG/GUG ratio was closely related to the intermolecular interactions of SPI-based ternary complex and the dynamical changing of its foaming properties. The SPI/GEG/GUG ternary complex with a GEG/GUG ratio of 2/3 exhibited the highest foamability (195 %) and comparable foam stability (99.17 %), which were 32.95 % and 2.99 % higher than that of SPI/GEG binary complex. At this ratio, GUG promoted the interactions between SPI and GEG, and bound to complex's surface through hydrogen bonding, resulting in the increase of particle size and surface charge, and the decrease of surface hydrophobicity. Although this reduced the diffusion of complex onto the air/water interface, it increased permeation rate and molecular rearrangement behavior, which were the potential mechanisms to improve the foaming properties. Additionally, the synergistic effect of GEG and GUG also enhanced the elastic strength and solid characteristics of foam systems. This study provided a theoretical guidance for the targeted modulation of foaming properties of multi-component aerated foods.

Effects of enzymatic hydrolysis combined with glycation on the emulsification characteristics and emulsion stability of peanut protein isolate

Peanut protein isolate (PPI) has high nutritional value, but its poor function limits its application in the food industry. In this study, peanut protein isolate was modified by enzymatic hydrolysis combined with glycation. The structure, emulsification and interface properties of peanut protein isolate hydrolysate (HPPI) and dextran (Dex) conjugate (HPPI-Dex) were studied. In addition, the physicochemical properties, rheological properties, and stability of the emulsion were also investigated. The results showed that the graft degree increased with the increase of Dex ratio. Fourier transform infrared spectroscopy (FTIR) confirmed that the glycation of HPPI and Dex occurred. The microstructure showed that the structure of HPPI-Dex was expanded, and the molecular flexibility was enhanced. When the ratio of HPPI to Dex was 1:3, the emulsifying activity and the interface pressure of glycated HPPI reached the highest value, and the emulsifying activity (61.08 m2/g) of HPPI-Dex was 5.28 times that of PPI. The HPPI-Dex stabilized emulsions had good physicochemical properties and rheological properties. In addition, HPPI-Dex stabilized emulsions had high stability under heat treatment, salt ion treatment and freeze-thaw cycle. According to confocal laser scanning microscopy (CLSM), the dispersion of HPPI-Dex stabilized emulsions was better after 28 days of storage. This study provides a theoretical basis for developing peanut protein emulsifier and further expanding the application of peanut protein in food industry.

Fabrication of soy protein nanoparticles based on metal-phenolic networks for stabilization of nano-emulsions delivery system

The use of soy protein isolate (SPI) nanoparticles as a stabilizer in nano-emulsion systems has garnered significant interest. While metal-phenolic networks (MPNs) have been explored for their multifunctional surface modification capabilities, their integration with food protein-based delivery systems remains less explored. In this study, we attempt to develop a novel strategy to encapsulate cinnamaldehyde using MPNs (EGCG-Fe3+) with self-assembling soy protein nanoparticles (SE-Fe NPs) as a stabilizer for nano-emulsions. UV, Raman, and X-ray photoelectron spectroscopy analyses demonstrated that SE-Fe NPs were generated through metal-phenolic coordination and covalent interactions. SE-Fe NPs had a narrower particle size distribution and enhanced radical scavenging (up to 3.35-fold), as well as thermal stability. Furthermore, the smaller droplet size, higher modulus, higher cinnamaldehyde encapsulation efficiency (from 63.5% to 84.2%), and improved bio-accessibility of SE-Fe NPs stabilized nano-emulsions delivery system demonstrated in this study shows promising future applications in the food industry.

Novel a-linolenic acid emulsions stabilized by octenyl succinylated starch -soy protein-epigallocatechin-3-gallate complexes: Characterization and antioxidant analysis

In this study, octenyl succinylated starch (OSAS)-soy protein (SP)-epigallocatechin-3-gallate (EGCG) complexes were designed to enhance the physical and oxidative stability of α-linolenic acid emulsions. Formations of OSAS-SP-EGCG complexes were confirmed via particle size, ξ-potential, together with fourier transform infrared (FTIR). A mixing ratio of 1:2 for OSAS to SP-EGCG resulted in ternary complexes with the highest contact angle (59.69°), indicating the hydrophobicity. Furthermore, the characteristics of α-linolenic acid emulsions (oil phase volume fractions (φ) of 10% and 20%) stabilized by OSAS-SP-EGCG complexes were investigated, including particle size, ξ-potential, emulsion stability, oxidative stability, and microstructure. These results revealed exceptional physical stability together with enhanced oxidative stability for these emulsions. Particularly, emulsions utilizing complexes having a 1:2 OSAS to SP-EGCG ratio exhibited superior emulsion stability. These findings provide theoretical support to the development of emulsions containing high levels of α-linolenic acid and for the broader application of α-linolenic acid in food products.

Improvement of physicochemical properties and quercetin delivery ability of fermentation-induced soy protein isolate emulsion gel processed by ultrasound

This study aimed to investigate the effects of ultrasonic treatment at different powers on the physicochemical properties, microstructure and quercetin delivery capacity of fermentation-induced soy protein isolate emulsion gel (FSEG). The FSEG was prepared by subjecting soy protein isolate (SPI) emulsion to ultrasonic treatment at various powers (0, 100, 200, 300, and 400 W), followed by lactic acid bacteria fermentation. Compared with the control group (0 W), the FSEG treated with ultrasound had higher hardness, water holding capacity (WHC) and rheological parameters. Particularly, at an ultrasonic power of 300 W, the FSEG had the highest hardness (101.69 ± 4.67 g) and WHC (75.20 ± 1.07%) (p < 0.05). Analysis of frequency sweep and strain scanning revealed that the storage modulus (G') and yield strains of FSEG increased after 300 W ultrasonic treatment. Additionally, the recovery rate after creep recovery test significantly increased from 18.70 ± 0.49% (0 W) to 58.05 ± 0.54% (300 W) (p < 0.05). Ultrasound treatment also resulted in an increased β-sheet content and the formation of a more compact micro-network structure. This led to a more uniform distribution of oil droplets and reduced mobility of water within the gel. Moreover, ultrasonic treatment significantly enhanced the encapsulation efficiency of quercetin in FSEG from 81.25 ± 0.62 % (0 W) to 90.04 ± 1.54% (300 W). The bioaccessibility of quercetin also increased significantly from 28.90 ± 0.40% (0 W) to 42.58 ± 1.60% (300 W) (p < 0.05). This study enriches the induction method of soy protein emulsion gels and provides some references for the preparation of fermented emulsion gels loaded with active substances.

Enhancing rheology and reducing lipid digestion of oil-in-water emulsions using controlled aggregation and heteroaggregation of soybean protein isolate-peach gum microspheres

There is a growing interest in developing highly viscous lipid foods using plant protein and polysaccharide gum-based emulsion technology. However, gaps remain in understanding the rheological, microstructural, and digestive properties of plant proteins like soybean protein isolate (SPI) in combination with various gums. This study investigates how combining SPI and peach gum (PG) affects rheology and lipolysis of oil-in-water (O/W) emulsions containing 20 wt% soybean oil. Emulsions with varying SPI and PG compositions including SPI-PG single and SPI/PG mixed droplet systems were prepared. Heating induced alterations in viscosity (e.g., SPI-PG from 14.88 to 90.27 Pa·s and SPI/PG from 9.66 to 85.32 Pa·s) and microstructure revealing aggregate formation at oil-water interface. The viscosity decreased significantly from the oral to intestinal phase (SPI-PG: 28.10 to 0.19 Pa·s, SPI/PG: 21.27 to 0.10 Pa·s). These changes affected lipid digestion, notably in SPI-PG and SPI/PG emulsions where a compact interface hindered lipolysis during digestion. Interestingly, free fatty acid (FFA) release during small intestinal phase followed a different order: SPI (82.51 %) > SPI-PG (70.77 %) > SPI/PG (63.60 %) > PG (56.09 %). This study provides insights into creating highly viscous O/W spreads with improved rheology, stability, and delayed lipid digestion, offering potential benefits in food product formulation.

Preparation and characterization of tilapia protein isolate - Hyaluronic acid complexes using a pH-driven method for improving the stability of tilapia protein isolate emulsion

This study aimed to investigate the non-covalent complexation between hyaluronic acid (HA) and tilapia protein isolate (TPI) on the stability of oil-in-water (O/W) TPI emulsion. The results showed that HA binds to TPI through electrostatic, hydrophobic, and hydrogen bonding interactions, forming homogeneous hydrophilic TPI-HA complexes. The binding of HA promoted the structural folding of TPI and altered its secondary structure during pH neutralization. The TPI-HA complexes presented significantly improved EAI and ESI (P < 0.05) when the HA concentration was 0.8 % (w/v). Emulsion characterization showed that HA promoted the transfer of TPI to the O/W interface, forming an emulsion with excellent stability, which, combined with the high surface charge and strong spatial site resistance effect of HA, improved TPI emulsion stability. Therefore, non-covalent complexation with HA is an effective strategy to improve the stability of TPI emulsion.

Extraction of Pithecellobium clypearia Benth polysaccharides by dual-frequency ultrasound-assisted extraction: Structural characterization, antioxidant, hypoglycemic and anti-hyperlipidemic activities

In this research, the extraction process of polysaccharides from Pithecellobium clypearia Benth (PCBPs) was optimized using dual-frequency ultrasound-assisted extraction (DUAE). The biological activities of PCBPs were investigated by in vitro antioxidant, hypoglycemic, and anti-hyperlipidemic assay. High-performance anion-exchange chromatography, high-performance gel permeation chromatography, SEM, UV-Vis spectroscopy, and FT-IR spectra were used to analyze the monosaccharide composition, molecular weight, microscopic morphology, and characteristic structure of PCBPs. The results showed that the maximum extraction rate of PCBPs was 9.90 ± 0.16% when the ultrasonic time was 8 min, the liquid-to-material ratio was 32 mL/g, and the ultrasonic power was 510 W. The PCBPs also possessed excellent in vitro antioxidant, hypoglycemic, and anti-hyperlipidemic activities. In addition, the average molecular weight of PCBPs was 15.07 kDa. PCBPs consisted of rhamnose, arabinose, galactose, glucose, xylose, mannose, and glucuronic acid, with the molar ratios of 11.07%, 18.54%, 48.17%, 10.44%, 4.62%, 4.96%, and 2.20%, respectively. Moreover, the results of SEM showed that PCBPs mainly showed a fine spherical mesh structure. The above studies provided a valuable theoretical basis for the subsequent in-depth study of PCBPs.

Fucoidan alleviates the inhibition of protein digestion by chitosan and its oligosaccharides

Chitosan (CTS) and chitosan oligosaccharides (COS) have been widely applied in food industry due to their bioactivities and functions. However, CTS and COS with positive charges could interact with proteins, such as whey protein isolate (WPI), influencing their digestion. Interaction among CTS/COS, FUC, and WPI/enzymes was studied by spectroscopy, chromatography, and chemical methods in order to reveal the role of FUC in relieving the inhibition of protein digestibility by CTS/COS and demonstrate the action mechanisms. As shown by the results, the addition of FUC increased degree of hydrolysis (DH) and free protein in the mixture of CTS and WPI to 3.1-fold and 1.8-fold, respectively, while raise DH value and free protein in the mixture of COS and WPI to 6.7-fold and 1.2-fold, respectively. The interaction between amino, carboxyl, sulfate, and hydroxyl groups from carbohydrates and protein could be observed, and notably, FUC could interact with CTS/COS preferentially to prevent CTS/COS from combining with WPI. In addition, the addition of FUC could also relieve the combination of CTS to trypsin, increasing the fluorescence intensity and concentration of trypsin by 83.3 % and 4.8 %, respectively. Thus, the present study demonstrated that FUC could alleviate the inhibitory effect of CTS/COS on protein digestion.

The effect of octenyl succinic anhydride-modified chitosan coating on DHA-loaded nanoemulsions: Physichemical stability and in vitro digestibility

Octenyl succinic anhydride-modified chitosan (OSA-CS) was synthesized and applied as a coating material to enhance the stability of docosahexaenoic acid (DHA)-loaded nanoemulsion. Due to the presence of the positively charged OSA-CS coating, the nanoemulsion exhibited a high positive zeta potential and two different layers. Compared with natural CS-coated nanoemulsion, OSA-CS-coated nanoemulsion showed improved storage stability (physical and chemical stability) and stability against environmental stresses (ionic strengths, temperatures and pH). Besides, OSA-CS-coated nanoemulsion protected encapsulated DHA from simulated gastric fluid damage better than that of natural CS-coated nanoemulsion, suggesting that OSA-CS-coated nanoemulsion had the potential to deliver more DHA into the small intestine. In conclusion, based on the comparison of two coating materials, natural chitosan and OSA-CS, it was found that the encapsulated nutrient was better protected by the OSA-CS coating. Such a finding will provide insights to broaden the application of modified chitosan in food delivery systems.

Enhanced functional properties of pea protein isolate microgel particles modified with sodium alginate: Mixtures and conjugates

Protein microgels are emerging as versatile soft particles due to their desirable interfacial activities and functional properties. In this study, pea protein isolate microgel particles (PPIMP) were prepared by heat treatment and transglutaminase crosslinking, and PPIMP were non-covalently and covalently modified with sodium alginate (SA). The effects of polymer ratio and pH on the formation of PPIMP-SA mixtures and conjugates were investigated. The optimal ratio of PPIMP and SA was found to be 20:1, with the optimal pH being 7 and 10, respectively. PPIMP-SA conjugates were prepared by Maillard reaction. It was found that ultrasound (195 W, 40 min) enhanced the degree of glycation of PPIMP, with a highest value of 37.21 ± 0.71 %. SDS-PAGE, browning intensity and FTIR data also confirmed the formation of PPIMP-SA conjugates. Compared with PPIMP and PPIMP-SA mixtures, PPIMP-SA conjugates exhibited better thermal stability, antioxidant, emulsifying and foaming properties, which opens up opportunities for protein microgel in various food applications.

Heat-Induced Gelation of Chickpea and Faba Bean Flour Ingredients

This study aimed to investigate the gelling behavior of faba bean (FB) and chickpea (CP) flour between 10 and 20% (w/w) concentration at pH 3.0, 5.0, and 7.0. Both sources formed at pH 3.0 and 5.0 self-standing gels with 12% (w/w) of flour, while 16% (w/w) of flour was required to obtain a gel at pH 7.0. During gelling between 40 and 70 °C, a sharp increase of the elastic modulus G' was observed in both flours, mainly due to water absorption and swelling of the starch, one of the major constituents in the ingredients. Increasing the temperature at 95 °C, G' increased due to the denaturation of globulins and therefore the exposure of their internal part, which allowed more hydrophobic interactions and the formation of the gel. After cooling, both FB and CP gels displayed a solid-like behavior (tan δ ranging between 0.11 and 0.18) with G' values at pH 3.0 and 5.0 significantly (p < 0.05) higher than those at pH 7.0, due to the lower electrostatic repulsions at pHs far from the isoelectric point. The rheological properties were supported by the water binding capacity values, confirming the better gels' strength described by rheological analysis. These results will enhance our understanding of the role of legume flours in formulating innovative and sustainable food products as alternatives to animal ones.

The aggregation behavior between soybean whey protein and polysaccharides of diverse structures and their implications in soybean isoflavone delivery

The use of polysaccharides to recover soybean whey protein (SWP) from whey wastewater is recognized as an effective approach. However, the recovery rate can vary due to differences in the structure and compound ratios of the polysaccharides involved. The interaction between SWP and polysaccharides (sodium alginate, SA; chitosan, CHI; carrageenan, CAR) at different ratio was investigated. We harnessed these complexes to fabricate emulsions aimed at delivering soybean isoflavones. The results showed that the addition of polysaccharides unfolded the structure of SWP. The intermolecular hydrogen bonds within SWP-SA were stronger than those of the other complexes. These structural changes showed consistency across different ratios. The mean particle size of the complexes increased. SWP-SA exhibited the lowest interfacial tension. The emulsion with SWP-SA at 300 W demonstrated superior stability, and the bioavailability of soybean isoflavones increased by 3-6 %. These results shed light on the promising potential of polysaccharide-based strategies for SWP recovery and the effective delivery of soybean isoflavones.

Interfacial engineering method to regulate the performances of bilayer emulsions co-stabilized by casein/butyrylated dextrin nanoparticles and chitosan

In present study, bilayer emulsions with different interfacial structures stabilized by casein/butyrylated dextrin nanoparticles (CDNP), chitosan (CS) and chitosan nanoparticles (CSNP) were prepared to overcome the limitations of conventional emulsions. The effects of chitosan morphology and incorporation sequences on the bilayer emulsions were examined. Bilayer emulsions prepared with CDNP as the inner layer and CS/CSNP as the outer layer were observed to have smaller droplet sizes (1.39 ± 86.74 um and 1.45 ± 7.87 um). Bilayer emulsions prepared with CDNP as the inner layer and CS as the outer layer exhibited the lowest creaming index (2.38 %) after 14 days of storage, indicating excellent stability. Furthermore, bilayer emulsion prepared with CDNP as the inner layer and CS as the outer layer also exhibited a uniform water distribution, excellent protein oxidative stability, and uniformly distributed droplets by the measurement of Low-field NMR, intrinsic tryptophan fluorescence and laser confocal laser scanning microscopy. These results indicated that the study provided a theoretical basis for the development and design of bilayer emulsions with different interfacial structures. This study also provides a new material for the preparation of delivery systems that protect biologically active compounds. Bilayer emulsions are promising for applications in traditional and manufactured food products.

Ovotransferrin Fibril-Gum Arabic Complexes as Stabilizers for Oleogel-in-Water Pickering Emulsions: Formation Mechanism, Physicochemical Properties, and Curcumin Delivery

This project aimed to explore the influence of the interaction between ovotransferrin fibrils (OTF) and gum arabic (GA) on the formation mechanism, physicochemical properties, and curcumin delivery of the oleogel-in-water Pickering emulsion. Cryo-scanning electron microscopy results showed that OTF-GA complexes effectively adsorbed on the oil-water interface, generating spatial hindrance to inhibit droplet coalescence. The texture analysis also proved that OTF-GA complexes endowed oleogel-in-water Pickering emulsion with preferable springiness (0.49 ± 0.03 mm), chewiness (0.43 ± 0.07 mJ), and adhesion (0.31 ± 0.01 mJ). By exploring the coalescence stability, droplet size, and rheological properties of OTF-GA complexes-stabilized oleogel-in-water Pickering emulsion (OGPE), the higher coagulation stability, larger average droplet size (46.22 ± 0.08 μm), and stronger gel strength were observed. The microrheological results also exhibited stronger attraction between the OGPE droplets, a more pronounced solid-like structure, and a slower speed of movement than OTF-stabilized oleogel-in-water Pickering emulsion (OPE). Meanwhile, OGPE significantly enhanced the extent of lipolysis, stability, and bioaccessibility of curcumin, suggesting that it possessed superior performance as a delivery system for bioactive substances. This project provided adequate theoretical references for protein-polysaccharide complexes-stabilized oleogel-in-water Pickering emulsion, and contributed to expanding the application of oleogel-in-water Pickering emulsion in the food industry.

Flavor of extruded meat analogs: A review on composition, influencing factors, and analytical techniques

Meat analogs are anticipated to alleviate environmental and animal welfare concerns as the demand for meat rises. High moisture extrusion is commonly employed to produce meat analogs, and its flavor could influence consumers' choice. To improve the development and market demand of extruded meat analogs, flavor precursors and natural spices have been used in high moisture extrusion process to directly improve the flavor profile of extruded meat analogs. Although there have been many studies on the flavor of high moisture extruded meat analogs, flavor composition and influencing factors have not been summarized. Thus, this review systematically provides the main pleasant and unpleasant flavor-active substances with 79 compounds, as well as descriptive the influence of flavor-active compounds, chemical reactions (such as lipid oxidation and the Maillard reaction), and fiber structure formation (based on extrusion process, extrusion parameters, and raw materials) on flavor of extruded meat analogs. Flavor evaluation of extruded meat analogs will toward multiple assessment methods to fully and directly characterize the flavor of extruded meat analogs, especially machine learning techniques may help to predict and regulate the flavor characteristics of extruded meat analogs.

Formation of pH-responsive hydrogel beads and their gel properties: Soybean protein nanofibers and sodium alginate

Hydrogel beads prepared from protein nanofibers are popular because of their safety, sleek appearance, and protection of biologically active substances. However, extreme external environmental variations, such as pH and temperature, can limit their practical application. To meet the application requirements of hydrogel beads in different environments, non-covalent mixtures of CaCl2 cross-linked soybean protein nanofibers (SNF) and sodium alginate (SA) were used to prepare hydrogel beads. In the present study, the hardness (782.48 g) and elasticity of hydrogel beads formed at SNF/SA = 7:3 and CaCl2 concentration of 0.1 mol/L were the maximum. Furthermore, the water content and pH swelling also reached a peak (98.68 %, 43.85 g/g) due to the best morphology and regular internal network structure. Meanwhile, the pH-responsive hydrogel beads with added anthocyanins were able to respond to the ambient pH under different temperatures and pH conditions and maintained color stability during 96 h of storage (ΔE < 5). In this experiment, a pH-responsive hydrogel bead based on soybean protein nanofiber (SNF) and sodium alginate (SA) was prepared by simple ionic crosslinking. It provides a theoretical and experimental basis for the future application of plant protein nanofibers as pH-responsive hydrogel materials.

Optimization and characterization of high internal phase double emulsion (HIPDE) stabilized by with soybean protein isolate, gallic acid and xanthan gum

This study aims to formulate a stable high internal phase double emulsion (HIPDE) using soybean protein isolate (SPI), gallic acid (GA), and xanthan gum (XG). To prepare HIPDE, W1/O was formulated with the water phase dispersed in the oil phase using polyglycerol polyricinoleate (PGPR) as a stabilizer. Thereafter, W1/O dispersed in W2 (SPI solution) was used. To stabilize the HIPDE, GA was added in W1 (0 or 1 %), XG was added in W2 (0 or 1 %), and the pH of the W phases was adjusted to acidic, neutral, and basic. The samples containing GA in W1 and XG in W2 did not phase out during the storage periods and maintained a higher ζ-potential value, a higher apparent viscosity, and a more sustainable droplet compared to others. These results were derived by the interaction between SPI and XG, SPI and GA, or GA and PGPR. Physicochemical crosslinks were formed, such as gallate-derived groups, SPI-GA complexation (Michael addition, Shiff base reaction), and hydrogen bonding. In conclusion, applying the SPI, GA, and XG to HIPDE would contribute to various industries such as food, medicine, and cosmetics.

Effects of κ-carrageenan on the emulsifying ability and encapsulation properties of pea protein isolate-grape seed oil emulsions

This work investigated the characteristics of pea protein isolate and κ-carrageenan complexes in stabilizing curcumin-loaded emulsions. The complexes structured by electrostatic attraction exhibited biphasic wettability with increased three-phase contact angles close to 90°. Morphological differences in the complexes were the critical factor influencing their emulsifying ability at various pH. As a steric barrier via increasing net negative charge (up to -54.7 ± 2.4 mV) and adsorbed protein content (92.57 %-97.61 %), the interfacial layer could retard droplet coalescence and improve emulsions stability. Rheological tests verified the higher viscoelasticity of emulsions by raising the oil fraction. After 4 weeks of heating treatment, the chemical stability of curcumin was prominently enhanced from 18.6 ± 0.2 % to 64.3 ± 5.7 %. The confirmed synergistic antioxidant activity between grape seed oil and curcumin in emulsions might facilitate the development of specific functional delivery systems in foods.

Effect of polysaccharide concentration on heat-induced Tremella fuciformis polysaccharide-soy protein isolation gels: Gel properties and interactions

The formation of a single soybean protein isolate (SPI) gel is limited by the processing conditions, and has the disadvantages of poor gel property, and it is usually necessary to add other biomacromolecules to improve its property. In this study, we investigated the effects of polysaccharide concentration on gel properties and interaction mechanisms of Tremella fuciformis polysaccharide (TFP)-SPI complexes. It was found that (1) the rheological properties, texture properties, water-holding properties, and thermal stability of TFP-SPI composite gels were improved with the addition of TFP (0.25-2.0 %, w/v) in a concentration-dependent manner; (2) hydrogen bond, the electrostatic interaction, hydrophobic interaction, and disulfide bond in the gel system increased with the increase of TFP concentration; (3) the electrostatic and hydrophobic interactions played an important role in the formation of the TFP-SPI composite gel while hydrogen bond formation was the least contributor to the binary composite gel network. Overall, TFP is not only a critical health food but also a promising structural component for improving the gel properties of SPI.

Ultrasound-assisted fabrication and stability evaluation of okra seed protein stabilized nanoemulsion

The structure and functional properties of okra seed protein (OSP) were characterized, the ultrasonic homogenization process of OSP nano-emulsion was optimized by response surface methodology (RSM), and its stability was also evaluated in this study. The results suggested that OSP was a high-quality plant protein, rich in glutamic acid. The molecular weight of its main subunits distributed in the range of 10-55 kDa, and some subunits were connected by disulfide bonds. Although the water and oil holding capacities of OSP were inferior to those of soy protein isolate (SPI), its emulsifying ability was superior to that of SPI. And the OSP concentration, ultrasonic time and ultrasonic power had obvious effects on the droplet size of nanoemulsion. The optimum process of OSP emulsion was determined as follows: OSP concentration 2.4 %, ultrasonic power 600 W, ultrasonic time 340 s. Under these conditions, the median droplet size of the nanoemulsion was 192.03 ± 3.48 nm, close to the predicted value (191.195 nm). And the obtained nano-emulsion exhibited high stability to the changes of pH, temperature and ionic strength in the environment. Our results can provide reference for the application of OSP, and promote the development of plant protein-based nanoemulsions.

Tunability of Pickering particle features of whey protein isolate via remodeling partial unfolding during ultrasonication-assisted complexation with chitosan/chitooligosaccharide

The potential of ultrasonication-driven molecular self-assembly of whey protein isolate (WPI) with chitosan (CS)/chitooligosaccharide (COS) to stabilize Pickering emulsions was examined, based on CS/COS ligands-induced partial unfolding in remodeling the Pickering particles features. Multi-spectral analysis suggested obvious changes in conformational structures of WPI due to interaction with CS/COS, with significantly higher unfolding degrees of WPI induced by COS. Non-covalent interactions were identified as the major forces for WPI-CS/COS conjugates. Ultrasonication enhanced electrostatic interaction between CS's -NH3 groups and WPI's -COO- groups which improved emulsification activity and storability of WPI-COS stabilized Pickering emulsion. This was attributed to increased surface hydrophobicity and decreased particle size compared to WPI-CS associated with differential unfolding degrees induced by different saccharide ligands. CLSM and SEM consistently observed smaller emulsion droplets in WPI-COS complexes than WPI-CS/COS particles tightly adsorbed at the oil-water interface. The electrostatic self-assembly of WPI with CS/COS greatly enhanced the encapsulation efficiency of quercetin than those stabilized by WPI alone and ultrasound further improved encapsulation efficiency. This corresponded well with the quantitative affinity parameters between quercetin and WPI-CS/COS complexes. This investigation revealed the great potential of glycan ligands-induced conformational transitions of extrinsic physical disruption in tuning Pickering particle features.