Effects of whey protein isolate-dextran glycosylation conjugate and different oils on the dispersion and in vitro digestibility of β-carotene emulsions.

β-carotene is a lipophilic substance with excellent antioxidant activity, but its bioactivity in the gastrointestinal tract is easily destroyed. Glycosylation can improve the emulsifying activity of Whey protein isolate(WPI). In this study, the effects of different oil phases(corn oil, coconut oil, soybean oil) and WPI-dextran(WPI-D) on the stability and digestion efficiency of emulsions loaded with β-carotene were investigated. The glycosylation of WPI with dextran was confirmed by SDS-PAGE and Atomic Force Microscope(AFM). The results of contact angle and surface tension experiments demonstrate that the interfacial properties of WPI-D particles are enhanced, allowing them to adsorb better at the oil-water interface, thereby improving the stability of the emulsion. The in vitro digestion results indicate that different oil phases and glycosylation have effects on the digestion rate of the emulsions and the bioaccessibility of β-carotene. The enhanced steric effect of WPI-D allows for the regulation of the release rate of free fatty acids (FFA). Coconut oil, rich in medium-chain fatty acids, is easily broken down and absorbed during digestion. The release rate of free fatty acids (FFA) is relatively high. This study provides a theoretical basis for controlling the release rate of bioactive substances through the regulation of oil phases and glycosylation.