Assessment of the effect of metal-phenolic networks on the IgE/IgG binding capacity and functional properties of whey protein isolates

Whey protein isolate (WPI) is an important food ingredient, but its high allergenicity limit its application. Recently, metal–phenolic networks (MPNs) have been shown to be effective in modifying proteins. The aim of this study was to evaluate the effects of MPNs formed from (−)-epigallocatechin-3-gallate (EGCG) and Fe 3+ on the structure, antibody-binding capacity, and functional properties of WPI. The results showed that MPN modification significantly reduced the antibody-binding capacity of WPI with immunoglobulin E and IgG binding reduced by 76.40 % and 84.74 %, respectively. Multispectroscopy and liquid chromatography–tandem mass spectrometry analyses suggest that this reduction is due to the destruction of conformational epitopes and the masking of linear epitopes by MPNs. Additionally, the introduction of phenolic hydroxyl groups through MPN modification led to conformational unfolding of WPI and reduced surface hydrophobicity, thereby enhancing its antioxidant activity, hypoglycemic ability, and foaming properties. These improvements were more pronounced at higher doses. Specifically, at a dosage of 96 mM, the total antioxidant capacity is 44.01 % and the foaming properties are 104 %. This study provides new insights into the modification of WPI and offers a promising strategy for developing hypoallergenic foods products.