Effects of transglutaminase glycosylated soy protein isolate on its structure and interfacial properties

Abstract

BACKGROUNDS The structural and interfacial properties of soybean protein isolate (SPI) after glycosylation by the transglutaminase method were studied. It is hoped that preliminary explorations will find a new food ingredient and broader application of SPI in the food industry. RESULTS The contents of free amino proves that transglutaminase can insert glucosamine into SPI through its transamination, and realize the enzymatic glycosylated SPI. The results of structure properties showed that a decrease in the content of the α‐helical structure indicates that the rigid structure of the protein is opened and the flexibility is increased. The blue shift of the maximum fluorescence intensity of soy protein isolate‐glucosamine with transglutaminase (SPI‐G) indicates the formation of a new substance; scanning electron microscopy shows that the SPI‐G powder can be seen at a magnification of 2000×, and the protein structure becomes soft. The results of interfacial properties found that enzymatic protein glycosylation exposes the internal hydrophobic groups of SPI, resulting in increased surface hydrophobicity, increased emulsification and emulsification stability, and reduced surface tension. CONCLUSION It shows that SPI‐G effectively improves the interfacial properties of SPI, providing a theoretical basis for the application of enzymatic glycosylation of SPI in the food industry. © 2021 Society of Chemical Industry

Fabrication of Bacterial Cellulose Nanofibers/Soy Protein Isolate Colloidal Particles for the Stabilization of High Internal Phase Pickering Emulsions by Anti-solvent Precipitation and Their Application in the Delivery of Curcumin

“…SPI presented a typical fluorescence emission peak at 340 nm, which was in agreement with a previous study (44). The wavelength of maximum emission did not show a distinct shift in both two types of colloid particles while the fluorescence intensity of colloid particles obviously (p < 0.05) decreased as a result of the presence of BCNs, which was in agreement with the reported result that the protein conformation was altered as a result of the interaction with other biopolymers (45). Moreover, the intensity of A-BCNs/SPI colloidal particles was significantly lower than that of S-BCNs/SPI colloidal particles, indicating that the effect of the anti-solvent precipitation on the protein conformation was more dramatically in comparison with that of a simple complex method.…”

Improved Oxidation Stability of Camellia Oil-in-Water Emulsions Stabilized by the Mixed Monolayer of Soy Protein Isolate/Bamboo Shoot Protein Complexes

“…According to Karaca et al ( 34 ), the more soluble proteins favored to reduce IFT because the proteins could shift to the interface. This phenomenon has also been proven by Zhang et al ( 35 ), who found that the IFT of all the four samples decreased as the SPI content increased, which helped more SPI molecules get adsorbed on the air-water interface.…”

“…As shown in Table 1, SPI had the highest IFT value of 50.72 mN/m. With the increasing ratio of BPC in the complex, the IFT value of the complex decreased to 50.25 also been proven by Zhang et al (35), who found that the IFT of all the four samples decreased as the SPI content increased, which helped more SPI molecules get adsorbed on the airwater interface.…”

Relationship between flexibility and interfacial functional properties of soy protein isolate: succinylation modification

“…8 The interfacial functional properties of proteins are mainly reflected in their emulsification and foaming properties, which are mainly influenced by their molecular flexibility, hydrophobicity, degree of aggregation, and interfacial tension. 9 Li et al 10 showed that the enhanced flexibility of glycosylated proteins contributes to their surface functional properties. Tang and Shen 11 also pointed out that the protein interfacial adsorption rate and interfacial stability could be accelerated by modulating the flexibility of bovine serum albumin.…”

“…Protein flexibility is closely associated with its conformation, reflecting its conformational motility and sensitivity to environmental changes 8 . The interfacial functional properties of proteins are mainly reflected in their emulsification and foaming properties, which are mainly influenced by their molecular flexibility, hydrophobicity, degree of aggregation, and interfacial tension 9 . Li et al 10 .…”