Controlled hydrolysis with preheating treatment and glutathione addition for enhanced foaming properties of soy protein isolate

This study investigates the effects of thermal treatment and glutathione addition on soy protein isolate (SPI) before pepsin-driven hydrolysis to obtain desirable hydrolysis with a high yield of soluble protein and good foaming properties. Various properties of SPI hydrolysates were measured to understand the change of SPI molecular composition related to foaming properties. The results revealed that the combination of glutathione and 55 (degrees) C thermal treatment yielded the most favorable SPI hydrolysate, characterized by excellent foaming capability (191.3%) and stability (93.1%), attributed to the highest relative composition (50.2%) of 7S. With the treatment temperature increasing from 55 C-degrees to 75( degrees )C, the reduction of 7S and generation of small molecular weight peptides negatively affected the foaming properties of SPI hydrolysates. The application of glutathione as a modulator, alongside mild thermal treatment, optimizes SPI hydrolysates for applications needing improved foaming and interfacial properties to achieve desirable foaming capability and stability. The study's findings offer promising potential for improving food products and formulations requiring enhanced foaming properties, with applications in industries like bakery and confectionery, leading to better texture, stability, and overall product quality.