Modification of structure and functionalities of ginkgo seed proteins by pH-shifting treatment

Modification and improvement of protein functionalities are important for expanding the applications of proteins in food. The objective of this study was to investigate the effects of pH-shifting treatments on the structural and functional properties of ginkgo seed protein isolate (GSPI). GSPI was exposed to acidic (pH 2.0-4.0) and basic (pH 10.0-12.0) pHs for 0, 0.5, 1, 2, and 4 h and subsequently neutralized for refolding. The pH-shifting treatments significantly increased GSPI solubility by 43-141% except for the treatment at pH 2.0, which decreased protein solubility by 16-39%. All pH-shifting treatments more than doubled the surface hydrophobicity of GSPI and significantly improved the emulsifying activity. The highest emulsifying activity was observed in the pH 2.0treated GSPI, which was 4.9-fold higher than the control. Acid-induced GSPI degradation likely promoted protein adsorption to the oil-water interface. In summary, the pH-shifting-modified GSPI may serve as a promising emulsifier in various food systems.

Automated summary

This study aimed to investigate the effects of pH-shifting treatments on the properties of GSPI, revealing that such treatments significantly increased protein solubility, surface hydrophobicity, and emulsifying activity, with the highest enhancement observed in GSPI treated at pH 2.0.