Fabrication of whey protein isolate fibrils-gallic acid complex high internal-phase Pickering emulsions: Dual functionality as a fat substitute and antioxidant

Abstract

This study develops high internal-phase Pickering emulsions using whey protein isolate fibrils complexed with gallic acid to replace fat and enhance antioxidant properties in food. Hydrophobic interactions and hydrogen bonding stabilized complexes, with zeta potential increasing from 26.56 ± 0.18 mV to 36.86 ± 0.61 mV as gallic acid concentration rose from 0.05 wt% to 0.5 wt%. The DPPH radical scavenging capacity peaked at 86.47 ± 0.40 % at 0.5 wt% GA. Emulsions stabilized with 0.5 wt% gallic acid exhibited the highest viscosity (3.37 Pa·s), smallest particle size, and superior mechanical strength. When used as a butter substitute in cookies, these emulsions reduced thiobarbituric acid values from 1.69 ± 0.02 mg MDA /kg to 0.88 ± 0.06 mg MDA/kg as substitution increased from 25 % to 100 % (p < 0.05). These findings demonstrate the potential of the complexes in creating multifunctional emulsions for healthier, sustainable food products.