Review on the loading efficacy of dietary tea polyphenols with milk proteins

Abstract In this review, the structural analysis and the loading efficacies of dietary tea polyphenols (+)-catechin (C), (−)-epicatechin (EC), (−)-epicatechingallate (ECG) and (−)-epigallocatechingallate (EGCG) with milk proteins β-lactoglobulin (β-LG), α-casein (αs1-casein) and β-casein were compared. The multiple spectroscopic results and docking sresults showed that the polyphenol bindings are via hydrophilic, hydrophobic and H-bonding contacts, where larger polyphenols form more stable protein conjugates. The order of protein affinity towards polyphenol was β-casein> α-casein> β-LG. Loading efficacy was 30–50% for polyphenol-protein adducts. The comparison showed milk proteins are capable of transporting tea polyphenols, which increases the bioavailability of these dietary micronutrients in solution.