不同烹饪方式及体外模拟消化环境对鲟鱼蛋白质氧化及消化性的影响

Effect of Different Cooking Treatments and in Vitro Digestion on Protein Oxidation and Digestibility of Sturgeon Fillets

研究水煮、汽蒸、微波、烤箱烤制、油炸5种烹饪方式对鲟鱼肉的脂肪和蛋白质氧化的影响,熟肉在模拟消化过程中后续氧化情况及这些氧化反应与蛋白质消化性的相互关系。结果表明,不同烹饪方式均导致鱼肉的脂质与蛋白质氧化,其中烤制与油炸的样品氧化程度最显著,这些氧化反应会在模拟胃肠道消化过程中进一步加深,尤其在模拟肠消化阶段变化更为强烈。在烹饪与消化过程中,脂质与蛋白质的相互氧化作用也非常明显。此外,不同烹饪方式引起的蛋白质氧化显著影响蛋白质在模拟消化过程中的水解程度。在胃消化阶段,烤制与油炸样品中大分子蛋白氧化聚集形成致密结构,降低了蛋白质消化性;小肠消化后,由于部分小分子肽类(<14 kDa)无法被彻底水解,各类熟制样品的游离氨基值均低于原料肉。

The effects of five different cooking methods （boiling, steaming, microwaving, oven baking and frying） on lipid and protein oxidation and their infiuence on the in vitro protein digestibility of sturgeon fillets were studied. Significant lipid and protein oxidative changes occurred in cooked fish fillets and were much more pronounced in roasted and fried samples. These changes were further reinforced during simulated digestion, especially intestinal digestion. A marked interaction between lipid and protein oxidation was also manifested during cooking and digestion. Furthermore, protein oxidation induced by cooking before digestion had a notable impact on proteolysis during digestion. Roasted and fried samples were less sensitive to pepsin due to polymerization of severely oxidized protein. After the completion of gastrointestinal digestion, there still existed some short peptides in cooked fish, especially roasted and fried fish, which could not be digested thoroughly.