BIOPOLYMERS PRODUCED BY CROSS-LINKING SOYBEAN 11S GLOBULIN WITH WHEY PROTEINS USING TRANSGLUTAMINASE

Heterogeneity of biopolymers was determined by cross-linking acetylate d-11S acidic subunits (Ac-11S) of soy protein with alpha-lactalbumin a nd beta-lactoglobulin. The extent of polymerization was determined by electrophoresis and HPLC. Differential scanning calorimetry (DSC) was used to determine thermal properties of starting proteins and biopolym ers. HPLC data demonstrated the absence of biopolymers From Ac-11S, ac etylated alpha-lactalbumin and acetylated beta-lactoglobulin when each was incubated separately with transglutaminase (TG). However, Ac-11S formed biopolymers with alpha-lactalbumin and beta-lactoglobulin when TG was added. TG catalyzed the formation of heterologous and homologou s biopolymers from whey protein isolate (WPI) and soybean 11S globulin (11S). Cross-linking WPI and 11S provided biopolymers with improved h eat stability which may be useful to provide functionality to food pro ducts.