响应面法优化海鳗酶法脱脂工艺的研究

Optimization of Defatting Technology of Pike Eel by Alkaline Lipase

为了提高海鳗制品的氧化安全性,采用碱性脂肪酶对海鳗片进行脱脂试验,通过响应面试验筛选出该酶的最佳使用条件:酶用量38 U/mL,pH9.7,浸泡时间61 min,鱼液比1∶4(W/V),最适温度30℃。同时比较了脱脂海鳗片与未脱脂海鳗片的抗氧化效果,并通过气相色谱法(GC)考察了酶法脱脂对海鳗脂肪酸含量的影响。结果表明,海鳗片在上述最优脱脂条件下的脱脂率为50.02%,与理论预测值50.60%基本一致。脱脂对海鳗抗氧化酸败有一定的作用。脂肪酸分析结果表明,经过脱脂后,多不饱和脂肪酸相对含量有所增加,特别是二十碳五烯酸(EPA)几乎增加了一倍,说明该脂肪酶对EPA有一定的保留作用,即EPA等不饱和脂肪酸在脱脂过程中破坏较少或不会被破坏。

The defatting effect of Pike eel fillet by alkaline lipase was studied in order to improve the antioxidation safety of Pike eel products.The optimum conditions selected by response surface methodology were as follows： alkaline lipase dosage 38 U/mL,pH 9.7,marinating time 61 min,fish/liquid ratio 1/4（W/V）,temperature 30 ℃.Meanwhile,the antioxidant effects of defatted and not defatted pike eel fillet were compared,and the effects of defatting on Pike eel＇s fatty acid composition were determined by GC.Results： The defatting rate of Pike eel fillet in aforementioned condition is 50.02%,close to the estimated value of 50.60% attained by using regression model.The contents of polyunsaturated fatty acids increase after the defatting,especially the content of eicosapentaenoic acid（EPA） increases almost double,indicating that alkaline lipase could protect EPA,in other words,less or even no destruction arise for the unsaturated fatty acids,such as EPA,in the defatting process.