The structuring mechanism and in vitro digestion of novel EPA-rich medium- and long-chain triacylglycerol oleogels

In this study, fish oil (FO) and medium-chain triglyceride (MCT) was used to synthesize eicosapentaenoic acid (EPA) -rich medium- and long-chain triacylglycerol (MLCT). From the perspective of MLCT profile, the effects of MLCT (oil phase) on crystal structure, non-covalent interaction and in vitro digestion of monoglyceride oleogel were examined. The MML and LLM type triglycerides (MML structured triglycerides containing two medium-chain fatty acids and one long-chain fatty acid, LLM structured triglycerides containing one medium-chain fatty acid and two long-chain fatty acids) appeared in MLCT, but were not detected in FO and PM (physical mixture of MCT and FO). The TAG molecules in MLCT deeply participate in oleogel network construction through hydrogen bonding and van der Waals forces, which changed oleogel crystallization behavior. The G′, hardness, melting point of oleogels were FO-G > PM-G > MLCT-G > MCT-G. Final free fatty acid released level of oleogels were MLCT-G (90.01%) > MCT-G (75.30%) > PM-G (69.97%) > FO-G (67.07%). The newly generated MML and LLM in MLCT weaken oleogel structure and facilitate the digestion of fatty acids. • A novel EPA-rich medium- and long-chain triacylglycerol oleogel was constructed. • The properties of MLCT oleogel was highly dependent on triglyceride profile. • Medium and long chain triacylglycerol oleogel had the highest degree of lipolysis. • Newly generated triglyceride profiles (MML and LLM) weaken the oleogel structure.