Physicochemical and emulsifying properties of whey protein isolate (WPI)-polydextrose conjugates prepared via Maillard reaction

In this study, whey protein isolate (WPI) and polydextrose (PDX) were used to produce WPI-PDX covalent conjugates via dry-heating Maillard reaction, and their characteristics and functional properties including abilities to emulsify and stabilise the corn germ oil/water emulsions were measured. Compared with WPI alone, the WPI-PDX conjugates had higher water solubility and DPPH radical scavenging ability, and the derived emulsions exhibited good storage stability over 60 days prepared under these conditions: reaction time 24 h, conjugate concentration 4-6%, oil fraction ratio 0.6 and emulsion system pH 3-8. Further, we found that the emulsion possessed the best storage stability under the condition of 4% WPI-PDX conjugates and 0.6% oil fraction. These results provide a potent to prepare a beneficial Maillard conjugation following an optimised reaction condition and highlight the potential use of WPI-PDX conjugates as the emulsifier in food industry.

Automated summary

The WPI-PDX covalent conjugates produced via dry-heating Maillard reaction showed higher water solubility and DPPH radical scavenging ability compared to WPI alone, leading to emulsions with good storage stability over 60 days. The optimal condition for the best storage stability of the emulsion was found to be with 4% WPI-PDX conjugates and 0.6% oil fraction, highlighting the potential use of WPI-PDX conjugates as emulsifiers in the food industry.