Enhancing bioaccessibility of camellia seed oil through whey protein isolate-quercetin complex stabilized emulsions

Camellia seed oil (CSO) exhibits poor dispersibility and low bioaccessibility during digestion. In this study, a whey protein isolate-quercetin (WPI-Que) complex was developed to fabricate CSO-in-water emulsions. The optimal complex (10 mg Que. was dissolved in 100 mL WPI solution) showed favorable physicochemical and emulsifying properties, and the formation of the complex originated from quercetin-induced conformational changes of WPI structure. Furthermore, the emulsion consisting of 5 g CSO and 10 mL emulsifier solution exhibited a uniform droplet distribution and an absolute zeta potential above 30 mV. More importantly, the emulsion exhibited higher bioaccessibility compared to bulk oil, with the maximum FFA release of 69.33 ± 0.99% and lipolysis rate of 0.0531 min^-1. These findings suggest that the WPI-Que complex can be used as emulsifier for constructing CSO delivery in functional food systems.