Fabrication and characterisation of whey protein isolate-propolis-alginate complex particles for stabilising α-tocopherol-contained emulsions

Dairy proteins are being used as carrier materials for the co-encapsulation and protection of bioactive nutrients because of their emulsification and complexation with polysaccharides. In this study, whey protein isolate (WPI)-propolis and WPI-propolis-algin ate complex particles were fabricated at pH 7.0 and characterised in term of size distribution, z-potential, antioxidant activity, and propolis encapsulation. The encapsulation efficiency of propolis was above 80% when 5 mg mL(-1) WPI was incorporated. Propolis and alpha-tocopherol were further co-encapsulated in sunflower oil emulsions stabilised by the complex particles. About 92% alpha-tocopherol and 72% propolis were co-encapsulated in the inner oil phase and the oil-water interface of emulsions, respectively. Propolis and/or alginate improved the stability of alpha-tocopherol during storage, while sodium alginate counteracted the positive effect of propolis on the vitamin stability during enzymatic hydrolysis. The data gathered here would expand the use of biopolymer-stabilised emulsions for multi-nutraceutical delivery. (C) 2020 Elsevier Ltd. All rights reserved.