Interaction of β-conglycinin with catechin-impact on physical and oxidative stability of safflower oil-in-water emulsion

The study aimed at improving the antioxidant activity of β-conglycinin to enhance the oxidative and physical stabilities of safflower oil-in-water emulsion stabilized by β-conglycinin. Heating promoted binding affinity and antioxidant activity of β-conglycinin. Catechin and chlorogenic acid showed higher binding affinities towards unheated (or heated) β-conglycinin than caffeic acid and quercetin. The enhancement efficiencies of the phenolics on the antioxidant activity of unheated (or heated) β-conglycinin decreased in the order of catechin > quercetin > chlorogenic acid > caffeic acid. Hydrophobic force and hydrogen bonding were the important binding forces for the selected phenolics to β-conglycinin. The complexation with catechin has no side effect on interfacial behavior and emulsifying property of β-conglycinin. The use of heated β-conglycinin-catechin complex as an emulsifier for preparing safflower oil emulsion effectively improved the oxidative and physical stabilities of the emulsion treated with lipoxygenase through inhibition of lipid oxidation, protein carbonyl formation and sulfhydryl loss.