Improved functional properties of wheat gluten hydrolysate by covalent conjugation with chlorogenic acid

Appropriate modification of wheat gluten with polyphenols or other natural compounds can greatly increase its functional properties and provide a high-quality protein source at a relative lower price. In this paper, covalent modification of wheat gluten hydrolysate (WGH) was performed with chlorogenic acid (CGA) by free-radical grafting. The structural changes in WGH by conjugating with CGA were characterised by ultraviolet spectrum, FTIR spectroscopy, differential scanning calorimeter (DSC) and fluorescence scanning, as well as physicochemical properties and biological functions. Results showed that WGH-CGA conjugates had higher thermal stability, better emulsifying and foaming capabilities, stronger antioxidant activity and lower allergenicity than the non-conjugated WGH. These findings indicated that the WGH-CGA conjugates had potential use value as functional food materials and additives in the food industry.