Investigation of the in vitro digestion fate and oxidation of protein-based oleogels prepared by pine nut oil

Pine nut oil (PNO) was gelled by solvent exchange and absorption methods through soy protein-tannic acid covalent hydrogel. The current study aimed to compare the in vitro digestion of oleogels prepared by different methods: solvent exchange (network oleogel [SNO] and particulate oleogel [SPO]) and absorption methods (AO), and probe the effect of oleogelation on oxidation. Results showed that the preparation affected the physicochemical properties of oleogels; during in vitro digestion, lipolysis was delayed for the oleogels as compared to that for PNO, and the extent of lipolysis followed the order of AO > SNO > SPO > PNO. The fatty acid profile in the micelle fraction demonstrated enhanced solubilization of unsaturated fatty acids (UFAs), especially pinolenic acid. During storage, oleogels had lower peroxide, thiobarbituric acid, and conjugated diene values than PNO, indicating superior oxidation stability. Thus, this work provides valuable directions for designing a delivery system to facilitate UFAs digestion and improve the oxidation stability of PNO.