Assessment of transglutaminase catalyzed cross‐linking on the potential allergenicity and conformation of heterologous protein polymers

Transglutaminase (TGase)-mediated cross-linking has gained significant attention due to its potential to reduce the allergenicity of food proteins. This study investigates the effects of TGase cross-linking on allergenicity and conformational modifications in a dual-protein system comprising soy protein isolate (SPI) and β-lactoglobulin (β-LG). The results showed that TGase cross-linking effectively decreased the allergenic potential of both SPI and β-LG, with a more pronounced reduction observed in the allergenicity of soy protein in the dual-protein system. SDS-PAGE analysis revealed that the 7S and 11S subunits of soy protein were more easily cross-linked than β-LG. Secondary structure analysis indicated that TGase treatment disrupted β-sheet structures, increased the content of random coils, and enhanced protein flexibility. Ultraviolet absorption and intrinsic fluorescence analyses confirmed these structural alterations, with TGase treatment exposing additional aromatic amino acids. A reduction in free sulfhydryl groups and altered intermolecular forces further corroborated the occurrence of cross-linking. These findings suggest that TGase-mediated cross-linking effectively reduced the allergenicity of SPI and β-LG by modifying their conformations, offering potential strategies for the development of hypoallergenic dual-protein food products. PRACTICAL APPLICATION: This study has practical applications in the food industry to develop hypoallergenic food products, particularly those that combine soy and dairy proteins. By using TGase to cross-link these proteins, the allergenicity can be reduced, resulting in products that are safer for consumers with food allergies.