Amino Acid and Fatty Acid Composition and Nutritional Value Evaluation of Different Yak Meat Cuts
HOU Chengli1, LI Xin1, WANG Zhenyu1, HUANG Caiyan1, ZHANG Qiang2, LUO Zhang3, ZHANG Dequan1,*
1.Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Science, Beijing 100193, China; 2.Institute of Animal Husbandry and Veterinary, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa 850000, China; 3.College of Food Science, Tibet Agricultural and Animal Husbandry College, Linzhi 860000, China
Abstract：In order to determine the profiles of amino acids and fatty acids in different cuts of Tibetan yak meat, nine meat cuts including chuck, tenderloin, sirloin, topside, rump, shank, belly, shoulder, brisket were collected from yak carcasses for the measurement of protein content, fat content, ash content, amino acid and fatty acid composition. The results showed that protein contents of all cuts of yak meat ranged from 19.30% to 24.20%; the highest and lowest values were found in sirloin and belly, respectively. Fat contents ranged from 1.03% to 22.47%, significantly higher in belly was than in other parts (P < 0.05); topside, striploin, rump and shoulder contained low contents of fat (less than 1.5%). Among the 18 amino acids determined, glutamic acid was the most abundant, followed by lysine, aspartic acid, leucine and arginine. The content of amino acids in belly was significantly lower than that in other parts (P < 0.05). The proportion of essential amino acids to total amino acids in 9 different parts of yak beef ranged from 39.03% to 40.00%, which was close to the FAO/WHO recommended value. Loin and sirloin met the dietary need for amino acids. Valine was the limiting amino acid in chuck, topside, rump, shank, belly, shoulder and brisket. Total fatty acid contents of different meat cuts were in the following decreasing order: belly > chuck > tenderloin > rump > sirloin > brisket > shoulder > shank > topside. Oleic acid, palmitic acid and stearic acid were the major fatty acids in yak meat with lesser amounts of docosahexenoic acid, eicosapentaenoic acid and other n-3 fatty acids. Cluster analysis classified these 9 meat cuts into three categories: belly, chuck and other parts based on nutrient, amino acid and fatty acid composition. Overall, we concluded that the contents of protein, fat, amino acid, fatty acid and other nutrients in different parts of yak beef were different. These results can provide a theoretical basis for developing yak meat with high nutritional value and for healthy consumption.
2019, Vol. 33 
