(1.烟台大学 生命科学学院, 山东 烟台 264003;2.鲁东大学 食品工程学院, 山东 烟台 264001;3.滨州医学院 药学院, 山东 烟台 264003;4.齐鲁师范学院 物理与电子工程学院, 山东 济南 250200) 收稿日期:2022-07-02 基金项目:山东省自然科学基金青年基金项目(ZR2020QC219)
(1.College of Life Sciences, Yantai University, Yantai 264003, China;2.College of Food Engineering, Ludong University, Yantai 264001, China;3.School of Pharmacy, Binzhou Medical University, Yantai 264003, China;4.Department of Physics and Electronic Engineering, Qilu Normal University, Jinan 250200, China)
Aiming at the risk of hyperlipidemia, hypertension, hyperglycemia and other diseases caused by high fat intake, it was considered to be an effective way to achieve healthy diet without reducing sensory quality by directional design of food emulsion structure and regulating the interaction between food and gastrointestinal fluid to delay the lipid digestion. The physicochemical properties (particle size distribution, thermodynamic properties, rheological properties, etc.) of whey protein micro-gel particle (WPMP) prepared from whey protein concentrate (WPC) by combined heat-shearing treatment under different pH were investigated. The stability of emulsions added with WPMP in the digestive tract and the release rate of free fatty acid (FFA) were measured. The results showed that WPMP prepared at pH 5.5 had the relatively small median particle size of 6.63μm, the highest thermal stability, the lowest fluid index (n=0.06) and the better thixotropy (SR=0.42). The oil droplet size of the emulsion stabilized by WPMP was significantly smaller than that of the emulsion stabilized by WPC (P<0.05). And the minimum oil droplet size of emulsion stabilized obtained at addition of the WPMP prepared at pH 5.5 was 13.28μm. Compared with emulsion stabilized by WPC, WPMP stabilized emulsions had higher stability and lower FFA release rate in simulated gastrointestinal digestive juice. Emulsions stabilized by WPMP prepared under different pH had different FFA release rates. The study confirmed that WPMP had a certain barrier effect on the bile salt interface replacement and lipase-colipase interface adsorption in the digestive tract. Therefore, WPMP had a certain inhibitory effect on the lipid digestion and lipid absorption of emulsions. And it was regulated by the interfacial structure of WPMP. It was hoped that the research results could provide a reference for the directional design of emulsion structure to inhibit lipid digestion.