PH dominates the formation of ginkgo seed protein and whey protein composite gels

Abstract

This study aimed to investigate the impact of pH on gelation of ginkgo seed protein isolate (GSPI) and whey protein isolate (WPI). The GSPI-WPI composite gels were made by heating a mixture of 12% (w/v) GSPI and 12% (w/v) WPI in equal parts at 90 °C for 30 min at different pHs. Hardness, springiness, and water holding capacity (WHC) of the composite gels at pH 7.0, 8.0 were improved due to formation of a compacted network by disulfide crosslinking. GSPI-WPI formed weak, particulate gels at pH 3.0 with poor WHC. At pH 6.0, the formation of hydrogen bonding improved the rheology of the composite gels. In short, pH is an important quality determinant of the GSPI-WPI composite gels, which provides a basis for gel modification and application in food.