当雄牦牛肉的营养和风味特性

以市售西门塔尔牛肉（下文简称“市售牛肉”）作为对照组，研究当雄牦牛肉的营养和风味特性。采用高效液相色谱、气相色谱-质谱联用、凯氏定氮等方法分别分析当雄牦牛肉和市售牛肉中蛋白质、氨基酸、脂肪酸、挥发性风味物质、矿物质和维生素差异。结果表明：当雄牦牛肉中蛋白质含量（22.89 g/100 g）显著高于市售牛肉（P＜0.05），剪切力及蒸煮损失率显著低于市售牛肉（P＜0.05）；当雄牦牛肉中VB1、VE含量显著高于市售牛肉（P＜0.05），2 种牛肉中的VB2、VA含量无显著差异；当雄牦牛肉中总氨基酸、必需氨基酸、总脂肪酸及不饱和脂肪酸含量均显著高于市售牛肉（P＜0.05）；微量元素分析结果发现，当雄牦牛肉中锰、硒、镁、铁、钙元素的含量均显著高于市售牛肉（P＜0.05）；当雄牦牛肉及市售牛肉中分别检测出58、43 种挥发性风味物质，牦牛肉中醇类和酯类的种类及含量均高于市售牛肉，而市售牛肉中酚类、醛类、酮类及含氮化合物的含量均较高。因此，当雄牦牛肉具有较好的食用营养品质。

Nutritional and Flavor Characteristics of Yak Meat from Dangxiong,Tibet

The nutritional and flavor characteristics of yak meat from Dangxiong, Tibet were evaluated and compared with those of commercial Simmental cattle meat. High-performance liquid chromatography, gas chromatography-mass spectrometry, and the Kjeldahl method were used to analyze the contents of vitamins, volatile flavor substances, proteins, fatty acids, amino acids and minerals in the meat samples. Results showed that the content of protein in Dangxiong yak meat was 22.89 g/100 g, which was significantly higher than that of commercial beef (P < 0.05), and the shear force and cooking loss were significantly lower than those of commercial beef (P < 0.05). The contents of vitamin B1 and vitamin E in yak meat were significantly higher than those of commercial beef (P < 0.05). Yet there were no significant differences in the contents of vitamin B2 and vitamin A (P > 0.05) between the two meats. The amounts of total amino acids, essential amino acids, total fatty acids and unsaturated fatty acids in yak meat were significantly higher than in commercial beef (P < 0.05). Trace element analysis showed that the contents of manganese, selenium, magnesium, iron and calcium in yak meat were significantly higher than those in commercial beef (P < 0.05). A total of 58 and 43 volatile flavor substances were detected in yak meat and commercial beef, respectively. The numbers and amounts of alcohols and esters in yak meat were higher than in commercial beef. Phenols, aldehydes, ketones and nitrogen-containing compounds were more abundant in commercial beef. Consequently, Dangxiong yak meat had better eating and nutritional quality.