Fabrication and Characterization of Ultrasound and Microwave Pre-Treated Transglutaminase-induced Egg White Protein and Whey Protein Isolate Composite Gel

This study examines the effects of ultrasound and microwave pre-treatments on the gelation properties of egg white protein (EWP) and whey protein isolate (WPI) mixtures in different ratios (3:1, 1:1, and 1:3). Transglutaminase (TGase) was used to induce protein cross-linking, aiming to assess the influence of these treatments on the gel textural stability. The composite gels were prepared in the specified ratios and were characterized for water-holding capacity (WHC) and textural properties. The gel prepared in a ratio of 3:1 (EWP: WPI) exhibited the highest WHC (81.4%), hardness (18.32 g), cohesiveness (0.52), and adhesiveness (- 3.87 g.sec) among all the samples. This standardized mixture was subjected to ultrasound (US) and microwave (M) pre-treatment for the preparation of composite gels. The ultrasound pre-treatment was carried out at four different time durations, i.e., 10, 20, 30, and 40 min, while the microwave pre-treatment was carried out at 3 different power levels, i.e., 100, 180, and 300 W. The pre-treated TGase-induced composite gels were characterized for their physico-chemical and structural characteristic. Both US and M pre-treatments significantly improved the physico-chemical properties, thermo-stability, and microstructure of the gels.