草地放牧藏绵羊不同月份肉品质及脂肪酸特征分析OA北大核心CSTPCD

In order to study the characteristics of meat quality of Tibetan sheep in different periods un-der natural grazing environment,the meat quality indexes,conventional nutritional components and fatty acid composition characteristics of each part of Tibetan sheep ewes in April,June,August and December were analyzed.The results showed that there were differences in the routine indexes and nutritional com-ponents of the muscles of different parts of Tibetan sheep at different time.the shear force,pH1h,meat color 24 h,and fat in April were significantly lower than those in August(P＜0.05).The water loss rate in April was significantly higher than that in August(P＜0.01).The cooked meat rate and protein content in June were significantly higher than those of other months(P＜0.05).The results of nutrient composi-tion analysis of mutton in different periods showed that the water and ash content in April was significantly higher in different parts than in June and August(P＜0.05).Crude protein content in June was significant-ly higher than that in other months(P＜0.05).Fatty acid determination results in different periods show myristic acid(C14:0)and heptadecanoic acid(C17:0)were the highest in different parts of the muscles in December,which was significantly higher than that in April(P＜0.05);pentadecanoic acid(C15:0)and myristic acid Dilute acid(C14:1)and 7 kinds of PUFA were highest in different parts of muscle in April;palmitic acid(C16:0),palmitoleic acid(C16:1),oleic acid(C18:1n9c)were the highest in different parts of muscle in August,which was significantly different from April(P＜0.05);total PUFA,PUFA/SFA,n-3 PUFA,n-6 PUFA and n-6/n-3 PUFA were all significantly higher in different parts in April than in other periods(P＜0.05).In summary,there are certain differences in the meat quality of grazing Tibetan sheep in different periods.August is the time when the meat quality is ideal,which can be used as the best reference time for slaughter.