脂肪酸不饱和度对带鱼肌球蛋白凝胶特性的影响

Effect of Fatty Acid Unsaturation on Gel Properties of Hairtail Myosin

为了研究脂肪酸不饱和度对肌球蛋白凝胶特性的影响,分析了添加四种不同饱和度的脂肪酸(硬脂酸、油酸、亚油酸和α-亚麻酸)后,带鱼肌球蛋白凝胶强度、持水性、化学作用力、流变特性、凝胶电泳、蛋白质二级结构等指标的变化规律。结果表明,肌球蛋白的凝胶强度和持水性会随着脂肪酸不饱和度的增加,呈先升高后降低的趋势,其中肌球蛋白-亚油酸复合体系的凝胶强度和持水性最高,与对照组相比分别提高了59.73%和15.73%。流变和电泳图谱结果显示,添加脂肪酸后肌球蛋白的储能模量(G’)和耗能模量(G’’)均高于对照组,且随着脂肪酸不饱和度的增加呈先增加后降低的趋势,并在肌球蛋白-亚油酸组达到最大值,而蛋白组成无显著性变化。红外光谱结果显示,脂肪酸不饱和度对肌球蛋白分子骨架没有明显影响,但硬脂酸、油酸和亚油酸会促使肌球蛋白构象朝不规则方向转变。综上,脂肪酸不饱和度对肌球蛋白的凝胶特性具有显著性影响,其中亚油酸改善带鱼肌球蛋白凝胶性能的效果最好。

In order to investigate effects of fatty acid unsaturation on the gel properties of myosin,four kinds of fatty acids(stearic acid,oleic acid,linoleic acid,andα-linolenic acid)with different saturation was added into hairtail myosin.The changes of gel strength,water holding capacity,chemical forces,rheological properties,gel electrophoresis and protein secondary structure of myosin were analyzed.The results showed that gel strength and water holding capacity of myosin increased first and then decreased with the increasing of fatty acid unsaturation.The gel strength and water holding capacity of myosin-linoleic acid composite system were the highest,increasing by 59.73%and 15.73%compared with control group,respectively.The results of the rheological and electropherogram indicated that the storage modulus(G')and loss modulus(G'')of myosin containing fatty acids were higher than that of control group.The G'and G''increased first and then decreased with the increasing of fatty acid unsaturation,and reached the maximum value in the myosin-linoleic acid group.However,there was no significant change in protein composition among all the groups.Infrared spectroscopy showed that the unsaturation of fatty acid had no obvious effect on the molecular backbone of myosin,but stearic acid,oleic acid,and linoleic acid promoted the conformation transform of myosin to irregular direction.In summary,fatty acid unsaturation had a significant effect on the gel properties of myosin,and linoleic acid was the best at improving the gel properties of hairtail myosin.