[关键词]
[摘要]
针对单、双脂肪酸甘油酯(亚麻酸)极易氧化的特点,该研究以乳清浓缩蛋白(WPC)、大豆分离蛋白(SPI)、酪蛋白酸钠(SC)和吐温80(T80)为乳化剂制备乳液,考察乳化剂类型对乳液的理化性质、氧化稳定性和消化特性的影响。结果表明,乳液均具有较小的粒径(131.97~224.87 nm),且在两周贮藏期内保持稳定。乳液包载能够提高单、双脂肪酸甘油酯(亚麻酸)的氧化稳定性,相比T80(过氧化值为377.40 mmol/kg),蛋白质对油脂的氧化保护效果更好,其中SPI稳定的乳液过氧化值最低为197.73 mmol/kg。体外模拟消化试验表明,乳化剂类型对游离脂肪酸的释放影响较小,但蛋白稳定的乳液在胃消化阶段更容易发生液滴聚集;亚麻籽油的脂质水解程度最低为23.93%,而单、双脂肪酸甘油酯(亚麻酸)的初始消化速度更快,最终脂解程度更高(46.33%)。因此,蛋白质乳液能有效提高单、双脂肪酸甘油酯(亚麻酸)的氧化稳定性,且单、双脂肪酸甘油酯(亚麻酸)相比亚麻籽油具有更好的消化效率,有望替代亚麻籽油作为人体亚麻酸的食物来源。
[Key word]
[Abstract]
Due to the high susceptibility of mono- and di-glycerides (linolenic acid) to oxidation, emulsions were prepared using whey protein concentrate (WPC), soybean protein isolate (SPI), sodium caseinate (SC), and Tween 80 (T80) as emulsifiers to investigate the effects of emulsifier type on the physicochemical properties, oxidation stability, and digestive characteristics of the emulsions. The results showed that all the emulsions had small particle (131.97~224.87 nm) and remained stable within two weeks of storage. Emulsion encapsulation improved the oxidation stability of mono- and di-glycerides (linolenic acid), while proteins as emulsifiers provided better protection efficiency against the oxidation of lipids than T80 (peroxide value of 377.40 mmol/kg). The SPI-stabilized emulsion had the lowest oxidation value of 197.73 mmol/kg. In vitro-simulated digestion experiments demonstrated that the type of emulsifier had insignificant effect on the release of free fatty acids. However, the protein-stabilized emulsions were more prone to droplet aggregation during the gastric digestion phase. Flaxseed oil had the lowest degree of lipid hydrolysis at 23.93%, while mono- and di-glycerides (linolenic acid) had a faster initial digestion rate and higher final lipid hydrolysis at 46.33%. Therefore, protein-stabilized emulsions can effectively improve the oxidation stability of mono- and di-glycerides (linolenic acid). Compared to linseed oil, mono- and di-glycerides (linolenic acid) have better digestive efficiency, which can be a promising food source of linolenic acid for humans in place of linseed oil.
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[基金项目]
国家自然科学基金面上项目(31972976)