Nano-microencapsulation of tea seed oil via modified complex coacervation with propolis and phosphatidylcholine for improving antioxidant activity

Abstract

Lipid oxidation of tea seed oil (TSO) limits its development in food industry. Microencapsulation is an effective solution, and nano-size may provide more biological activities for hydrophobic core than micron-size. In this study, by applying two novel types of wall materials, namely ethanol extract of propolis (EEP) and phosphatidylcholine (PC), a modified complex coacervation was proposed to construct EEP-PC-TSO (tea seed oil) nano-microcapsules. The influence of the pH of electrostatic adsorption, homogeneous pressure, and core/wall ratio on the physicochemical properties of the TSO nano-microcapsules, the effect of EEP as bioactive wall material on the oxidative stability of TSO, and the nano particle size on the antioxidant activity of EEP-PC-TSO nano-microcapsules were investigated. The results showed that, due to electrostatic adsorption, EEP-PC-TSO nano-microcapsules (445.23 nm–95.30 nm) were successfully prepared via the modified complex coacervation. The characterization results represented that the nano-microcapsules hold well nano-structure, morphology and interface characteristics. The EEP-PC cross-linked wall provided multifaceted protective effects on the oxidation of TSO in EEP-PC-TSO nano-microcapsules, and the nano-microencapsulation can synergistically improve the antioxidant activity of microcapsules. This nano-microcapsules will provide a potential significance for high-value applications of edible oil in food industry.