Gellan gum conjugation with soy protein via Maillard-driven molecular interactions and subsequent clustering lead to conjugates with tuned technological functionality

Nanoemulsions base on the Rice bran albumin-sweet potato leaf polyphenol-dextran complexes: Interaction mechanisms, stability and Astaxanthin release behaviour

In this study, rice bran albumin (RBA), sweet potato leaf polyphenols (SPLPs) and dextran were conjugated through covalent or non-covalent interactions to improve the stability and bioaccessibility of astaxanthin (AST) in emulsion systems. It was shown that the RBA-SPLPs-Dex ternary covalent complex demonstrated higher polysaccharide grafting, looser secondary structure, and exposed hydrophobic groups indicating that they were favourable for emulsion stabilisation. In long-term storage tests, RBA-SPLPs emulsifier modified by 50 mg/mL dextran (Dextran50) showed smaller particle size and cream index, respectively. Besides, the retention of loaded astaxanthin was improved by 59.43 % compared to the unmodified model, along with a strengthened inhibition of lipid oxidation in the storage experiment. Besides, Dextran50 also improved the environmental stress stability of the emulsion and demonstrated more efficient AST release behaviour during intestinal digestion. In conclusion, these emulsion systems stabilised with ternary complexes have great potential for the delivery of lipid-soluble bioactive ingredients.

Effects of Conjugation with Basil Seed Gum on Physicochemical, Functional, Foaming, and Emulsifying Properties of Albumin, Whey Protein Isolate and Soy Protein Isolate

Protein conjugation with the Maillard reaction has received considerable attention in the past decades in terms of improving functional properties. This study evaluated the changes in the techno-functional properties of whey protein isolate (WPI), soy protein isolate (SPI), and albumin (Alb) after conjugation with basil seed gum (BSG). The conjugates were developed via the Maillard reaction. Various analyses including FT-IR, XRD, SEM, SDS-PAGE, DSC, RVA, rheology, zeta potential, emulsion, and foaming ability were used for evaluating conjugation products. Conjugation between proteins (WPI, SPI, Alb) and BSG was validated by FT-IR spectroscopy. XRD results revealed a decrease in the peak of BSG after conjugation with proteins. SDS-PAGE demonstrated the conjugation of WPI, SPI, and Alb with BSG. DSC results showed that conjugation with BSG reduced the Tg of WPI, SPI, and Alb from 210.21, 207.21, and 210.90 °C to 190.30, 192.91, and 196.66 °C, respectively. The emulsion activity and emulsion stability of protein/BSG conjugates were increased significantly. The droplet size of emulsion samples ranged from 112.1 to 239.3 nm on day 3. Nanoemulsions stabilized by Alb/BSG conjugate had the smallest droplet sizes (112.1 and 143.3 nm after 3 and 17 days, respectively). The foaming capacity of WPI (78.57%), SPI (61.91%), and Alb (71.43%) in their mixtures with BSG increased to 107.14%, 85.71%, and 85.71%, respectively, after making conjugates with BSG. The foam stability of WPI (39.34%), SPI (61.57%), and Alb (53.37%) in their mixtures with BSG (non-conjugated condition) increased to 77.86%, 77.91%, and 72.32%, respectively, after formation of conjugates with BSG. Conjugation of BSG to proteins can improve the BSG applications as a multifunctional stabilizer in pharmaceutical and food industries.

Optimization of cold-induced aerated gels formed by Maillard-driven conjugates of SPI-gellan gum as an oil substitute in mayonnaise sauce

This research aimed at characterization of composite cold-set aerated gels composed of SPI-gellan gum Maillard conjugates. The optimized gel was eventually incorporated in mayonnaise sauce as an oil substitute. The optimum conditions were statistically determined as 1.5% SPI, 300 mM CaCl2, and 90 min heating time. All of which resulted 35% glycation degree and high molecular weight conjugates on top of SDS-PAGE injection wells. Increasing CaCl2 concentration enhanced the adsorption of conjugates at air-water interface, decreasing the density but increasing the WHC and hardness. Increasing heating time facilitated gelation which improved gel hardness. The optimized gel was microstructurally homogeneous with increased overrun (20.8%) and H-bonds. The rheological measurements showed viscoelastic gel network which was thermally stable up to 90 °C, besides increasing G', G" and η∗ at 85 °C. Substitution of optimized gel in mayonnaise sauce improved the nutritional value and thermal stability (77.13%), but declined calorie. The substituted mayonnaise sauce was greatly accepted by panelists. Thus, the aerated gel formed at optimum conditions had great structural and mechanical characteristics and its usage as an oil analogue induced a low-calorie mayonnaise sauce with acceptable sensory properties.

Cyclic Continuous Glycation Enhanced Dispersibility of Myofibrillar Protein: Reaction Efficiency and Sites Modification

Reaction efficiency in glycation lacks sufficient attention, leading to the waste of process costs. Cyclic continuous glycation (CCG) is an effective approach to accelerate covalent binding between myofibrillar protein (MP) and glucose. This study elucidated that CCG promoted the exposure of reactive glycated sites in MP with full unfolding of secondary and tertiary structures. Notably, the glycation rate was significantly increased by 65.43%. Physicochemical properties indicated that MP-glucose conjugates with high graft degree exhibited favorable solubility, dispersibility, and thermal stability. Furthermore, proteomics was applied to reveal the glycated sites and products in glycoconjugates of MP. Glycation preferentially acted on the tails of the myosin heavy chain. The glucosylation modification on the head region was enhanced by CCG contributing to the inhibition of the head-head interaction. Overall, this study systematically clarifies the mechanism of CCG, providing a theoretical basis for the application of glycation in innovative meat products.

Effect of Mono- and Polysaccharide on the Structure and Property of Soy Protein Isolate during Maillard Reaction

As a protein extracted from soybeans, soy protein isolate (SPI) may undergo the Maillard reaction (MR) with co-existing saccharides during the processing of soy-containing foods, potentially altering its structural and functional properties. This work aimed to investigate the effect of mono- and polysaccharides on the structure and functional properties of SPI during MR. The study found that compared to oat β-glucan, the reaction rate between SPI and D-galactose was faster, leading to a higher degree of glycosylation in the SPI-galactose conjugate. D-galactose and oat β-glucan showed different influences on the secondary structure of SPI and the microenvironment of its hydrophobic amino acids. These structural variations subsequently impact a variety of the properties of the SPI conjugates. The SPI-galactose conjugate exhibited superior solubility, surface hydrophobicity, and viscosity. Meanwhile, the SPI-galactose conjugate possessed better emulsifying stability, capability to produce foam, and stability of foam than the SPI-β-glucan conjugate. Interestingly, the SPI-β-glucan conjugate, despite its lower viscosity, showed stronger hypoglycemic activity, potentially due to the inherent activity of oat β-glucan. The SPI-galactose conjugate exhibited superior antioxidant properties due to its higher content of hydroxyl groups on its molecules. These results showed that the type of saccharides had significant influences on the SPI during MR.

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.

Behavior of protein-polysaccharide conjugate-stabilized food emulsions under various destabilization conditions

The sensitivity of protein-stabilized emulsions to flocculation, coalescence, and phase separation under destabilization conditions (i.e., heating, aging, pH, ionic strength, and freeze-thawing) may limit the widespread use of proteins as effective emulsifiers. Therefore, there is a great interest in modulating and improving the technological functionality of food proteins by conjugating them with polysaccharides, through the Maillard reaction. The present review article highlights the current approaches of protein-polysaccharide conjugate formation, their interfacial properties, and the behavior of protein-polysaccharide conjugate stabilized emulsions under various destabilization conditions, including long-term storage, heating and freeze-thawing treatments, acidic conditions, high ionic strength, and oxidation. Protein-polysaccharide conjugates are capable of forming a thick and cohesive macromolecular layer around oil droplets in food emulsions and stabilizing them against flocculation and coalescence under unfavorable conditions, through steric and electrostatic repulsion. The protein-polysaccharide conjugates could be therefore industrially used to design emulsion-based functional foods with high physicochemical stability.

Assessing the protection mechanisms on Enterobacter aerogenes ATCC 13048 by potentially probiotic strain Lacticaseibacillus casei XN18: An experimental and modeling study

In this study, Lacticaseibacillus casei XN18 had a remarkable resistant to simulated gastrointestinal conditions, hydrophobicity (38.60%), auto-aggregation (29.80%), co-aggregation (21.10%), adhesion (9.50%), anti-adhesion (24.40-36.90%), antioxidant activity (46.47%), cholesterol assimilation (41.10%), and antimicrobial effect on some pathogenic microorganisms. The modified double layer method, and Enterobacter aerogenes (inhibition zone (IZ) = 9.10 mm) and Listeria monocytogenes (IZ = 14.60 mm) were the most sensitive and resistant pathogens to the probiotic strain. The Lb. casei was sensitive to ciprofloxacin (IZ = 23 mm) and nitrofurantoin (IZ = 25.10 mm), semi-sensitive to imipenem (IZ = 18.80 mm), erythromycin (IZ = 16.90 mm), and chloramphenicol (IZ = 17.90 mm), and resistant to ampicillin (IZ = 9.60 mm) and nalidixic acid (IZ = 9.90 mm). The Lb. casei showed no haemolytic and DNase properties, and it could therefore be used for health-promoting purposes. In the next section, multilayer perceptron (MLP) neural network (NN) and gaussian process regression (GPR) models with k-fold cross validation method were used for predicting the rate of probiotic viability based on three levels of pH and time. The results showed that GPR has the lowest error. The mean absolute percentage error (MAPE), root mean absolute error (RMSE) and coefficient of determination (R²) for GPR and MLP models were 1.49 ± 0.40, 0.21 ± 0.03, 0.98 ± 0.05 and 6.66 ± 0.98, 0.83 ± 0.23 0.82 ± 0.09, respectively. So, the GPR model can be reliably used as a useful method to predict the probiotic viability in similar cases.

Changes in fat uptake, color, texture, and sensory properties of Aloe vera gel-coated eggplant rings during deep-fat frying process

There is a widespread use of deep-fat frying in both domestic and industrial sections, and deep-fat fried foods are extremely popular due to their taste, color, and crispy texture. Human health can be, however, seriously compromised by the excessive consumption of oil, especially saturated fats and trans fatty acids. The use of hydrocolloids in inhibiting oil absorption has garnered considerable attention. This study was therefore aimed to lower the oil absorption in eggplant rings during the deep-fat frying process with the aid of Aloe vera gel coating. The effects of gel concentration (0%, 50%, and 100%), frying time (2, 5, and 8 min), and frying temperature (160°C and 180°C) on the oil uptake, moisture content, texture, color, and sensory properties of the eggplant rings were evaluated. The gel coating led to a decrease in oil uptake (up to 50%), hardness (up to 0.98-fold), ΔE (up to 0.89-fold), and overall acceptance (up to 0.85-fold), and an increase in moisture content (up to 1.47-fold) and lightness (up to 1.14-fold) of the samples. The frying time and temperature also influenced the physiochemical and sensory properties of the eggplant rings. The sample coated with 50% gel and fried at 180°C for 8 min had lower oil content and water loss with the highest acceptance rate in terms of taste, color, odor, texture, and appearance. The Aloe vera gel could be, therefore, a good candidate with high nutritional and economic value to reduce oil uptake in fried food products.