青海牦牛肉与秦川牛肉氨基酸和脂肪酸的比较研究

通过青海牦牛肉与秦川牛肉的氨基酸和脂肪酸的比较研究,分析青海牦牛肉品质的特性及其潜在优势.选取秦川牛肉,青南、大通和环青海湖地区的成年牦牛肉以及大通犊牦牛肉进行氨基酸和脂肪酸的相关研究.结果表明:牦牛肉各组的蛋白质含量高于秦川牛肉,但差异不显著(P＞0.05);脂肪含量都低于秦川牛肉,差异极显著(P＜0.01).青南地区成年牦牛肉的必需氨基酸/非必需氨基酸(EAA/NAA)值、必需氨基酸/氨基酸总量(EAA/TAA)值、18∶2cis-12,15、α-亚麻酸、20∶0、多不饱和脂肪酸(PUFA)、必需脂肪酸(EFA)、多不饱和脂肪酸/脂肪酸总量(P∶S)值和n-3多不饱和脂肪酸都显著高于秦川牛肉(P＜0.05或P＜0.01)；16∶0、二十碳五烯酸(EPA)和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).大通成年牦牛肉的赖氨酸、组氨酸和15∶0都显著高于秦川牛肉(P＜0.05或P＜0.01)；月桂酸、亚油酸、PUFA、EFA、n-6多不饱和脂肪酸和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).环湖地区成年牦牛肉的脯氨酸、15∶0、16∶1cis-9、17∶0和18∶2cis-12,15都显著高于秦川牛肉(P＜0.05或P＜0.01)；月桂酸和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).大通犊牦牛肉的色氨酸、肉豆蔻酸、17∶1cis-9、18∶1cis-11、亚油酸、α-亚麻酸、20∶3cis-5,8,11、20∶3cis-7,10,13、花生四烯酸(AA)、EPA、PUFA、EFA、P∶S值、n-3多不饱和脂肪酸和n-6多不饱和脂肪酸都显著高于秦川牛肉(P＜0.05或P＜0.01)；脯氨酸、14∶1cis-9、棕榈酸、17∶0、油酸、SFA、MUFA和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).结论:青海成年牦牛肉的蛋白质和必需氨基酸含量稍高于秦川牛肉,组成与秦川牛相近,但犊牦牛肉的氨基酸含量稍差一些.牦牛肉的n-6/n-3多不饱和脂肪酸比秦川牛肉合理,都在4.0左右,其中犊牦牛肉的P∶S值为1.15,说明牦牛肉的脂肪酸品质优,尤其是犊牦牛肉.

Comparative Studies on Beef Amino Acid Composition and Fatty Acid Composition of Qinghai Yak and Qinchuan Cattle

Meat characteristics and potential superiority of Qinghai yak were analyzed by comparing differences in amino acid composition and fatty acid composition from Qinchuan cattle. Meat samples from Qinchuan cattle and adult yaks in South Qinghai, Datong county and the region around Qinhai Lake were analyzed for amino acid composition and fatty acid composition. The results obtained showed that： 1） protein content was higher in yak meat regardless of the region or the age than in Qinchuan cattle meat, with no statistically significant difference （P 〉 0.05）, while fat content in Qinchuan cattle meat was statistically significantly higher （P 〈 0.01）; 2） the meat of adult yaks from South Qinghai exhibited significantly increased levels of EAA/NAA ratio, EAA/TAA ratio, 18：2 cis-12,15, a-linolenic acid, arachidic acid, eicosapentaenoic acid, polyunsaturated fatty acids （PUFA）, essential fatty acids, PUFA/SFA ratio and n-3 polyunsaturated fatty acids （P 〈 0.05 or P （0.01）, but significantly decreased levels of palmitic acid, EPA and n-6/n-3 ratio （P 〈 0.05 or P （ 0.01）; 3） the meat of yaks from Datong county was statistically significantly higher than Qinchuan cattle meat in the levels of lysine, histidine and pentadecanoic acid （P 〈 0.05 or P 〈 0.01） but significantly lower in the levels of lauric acid, linoleic acid, PUFA, EFA, n-6 PUFAs and n-6/n-3 ratio （P 〈 0.05 or P 〈 0.01）; 4） the meat of adult yaks from the region around Qinghai Lake revealed significantly higher levels of praline, pentadecanoic acid, palmitoleic acid, heptadecanoic acid and C18：2 cis-12,15 and significantly lower levels of laurie acid and n-6/n-3 ratio when compared to Qinchuan cattle meat （P 〈 0.05 or P 〈 0.0 1）; 5） significantly higher levels of tryptophan, tetradecanoic acid, 10-heptadecenoic acid, cis-vaccenic acid, linoleic acid, a-linolenic acid, C20：3 cis-5,8,11, C20：3 cis-7,10,13, arachidonic acid, EPA, PUFA, EFA, PUFA/SFA ratio and n-6/n-3 ratio were found in the meat of yak calves from Datong as well as significantly lower levels of praline, C~4：1 cis-9, palmitic acid, heptadecanoic acid, oleic acid, SFA, MUFA and n-6/n-3 ratio （P 〈 0.05 or P 〈 0.01）. From this study we concluded that the meat of adult yaks from Qinghai contains slightly higher amounts of proteins and essential amino acids than Qinchuan cattle meat despite having similar amino acid composition. Despite containing slightly less amino acids, yak calf meat is more rational in n-6/n-3 ratio than Qinchuan cattle meat, both fluctuating around 4, and shows a PUFA/SFA ratio of 1：1.5, suggesting that yak meat contains high-quality fatty acids, especially the meat of yak calves.