Partition and digestive stability of α-tocopherol and resveratrol/naringenin in whey protein isolate emulsions

Co-encapsulation of multiple bioactive components is an emerging field that shows promise as an approach to develop functional foods. Hydrophobic components are generally dissolved in the inner oil phase of protein-stabilised emulsions. Some components may co-adsorb to oil droplet surfaces, due to the ligand-binding properties of proteins. In this study, alpha-tocopherol and resveratrol/naringenin were co-encapsulated in emulsions stabilised by whey protein isolate (WPI). alpha-Tocopherol was totally encapsulated and its partitioning inside oil droplets was about 3.3 times that bound by free WPI in the aqueous phase. The total encapsulation efficiency for resveratrol or naringenin was 52% and 58%, respectively. Addition of resveratrol improved digestive stability of alpha-tocopherol, but naringenin did not. Co-encapsulation with alpha-tocopherol had no significant influence on the digestive stability of resveratrol/naringenin. The data gathered here should be useful for the delivery of bioactive components with different solubilities. (C) 2019 Elsevier Ltd. All rights reserved.