四川省4个牦牛品种肉品质、营养成分及重金属含量的比较分析

Comparative analysis of meat quality,nutrient composition and heavy metal content of 4 yak breeds in Sichuan Province

为了比较不同品种牦牛的肉品质、营养成分及重金属含量,试验选择自然条件下纯放牧、生长发育正常、平均体重为296.88 kg、健康的3.5岁拉日马牦牛、理塘牦牛、亚丁牦牛和色达成年牦牛各6头(公母各半),屠宰排酸24 h后,采集外脊、辣椒条、小黄瓜条3个部位肌肉组织样品进行肉品质(肉色值、pH值、熟肉率及剪切力)的测定,采集外脊组织样品进行氨基酸、矿物质和重金属含量的测定,并比较分析4个品种各指标的差异。结果表明:拉日马牦牛外脊部位和辣椒条部位的L^(*)值、3个部位的a^(*)值和b^(*)值及辣椒条部位与小黄瓜条部位的剪切力最高,外脊部位的pH值及辣椒条部位与小黄瓜条部位的pH值和熟肉率最低;理塘牦牛辣椒条部位的a^(*)值和b^(*)值及外脊部位的pH值最低,小黄瓜条部位的L^(*)值最高;亚丁牦牛外脊部位的pH值和熟肉率及小黄瓜条部位的pH值最高,外脊部位的各肉色值、小黄瓜条部位的b^(*)值及3个部位的剪切力最低;色达牦牛外脊部位的剪切力、辣椒条部位的pH值和熟肉率及小黄瓜条部位的熟肉率最高;外脊部位的熟肉率、辣椒条部位的L^(*)值及小黄瓜条部位的a^(*)值最低。拉日马牦牛肉的总氨基酸(total amino acid,TAA)、非必需氨基酸(non-essential amino acid,NEAA)含量最高,色达牦牛肉必需氨基酸(essential amino acid,EAA)含量最高,理塘牦牛肉的TAA和EAA含量最低;拉日马牦牛、亚丁牦牛和色达牦牛肉的EAA/TAA值在38.36%~38.96%之间,EAA/NEAA值在62.03%~63.89%之间;而理塘牦牛肉的EAA/TAA值和EAA/NEAA值分别为35.89%和55.84%。亚丁牦牛肉的钙含量最高,镁含量最低;亚丁牦牛和色达牦牛肉的铁含量较高;理塘牦牛肉的锌含量最低。4个品种牦牛肉中铅、镉、铬、砷、汞含量均低于国家限量标准值。说明不同品种牦牛的肉品质及营养成分不同,拉日马牦牛肉整体肉色最鲜艳,亚丁牦牛肉最嫩,拉日马牦牛、亚丁牦牛、色达牦牛肉的蛋白质品质较高,且4个品种牦牛肉的重金属含量均达到食用安全国家标准。

In order to compare the meat quality,nutrient composition and heavy metal content of 4 breeds of yak,6 healthy 3.5 year old Larema yak,Litang yak,Yadin Yak and Serda yak with normal growth and development,average body weight of 296.88 kg(half male and half female)were selected under natural conditions.24 h after slaughtering and discharging acid,muscle tissue samples from 3 parts of outer ridge,pepper strip and cucumber strip were collected for meat quality determination(meat color value,pH value,cooked meat rate and shear force),and outer ridge tissue samples were collected for amino acid,mineral and heavy metal content determination,and the differences of various indexes among the 4 varieties were compared and analyzed.The results showed that the L^(*)values,a^(*)values and b^(*)values of 3 parts and the shear force of pepper strip and cucumber strip were the highest,while the pH values of outer ridge,pH values and cooked meat rate of peper strip and cucuber strip parts were the lowest in Larema.The a^(*)values,b^(*)values of pepper strip parts and pH values of the outer ridge parts were the lowest;L^(*)value of cucumber strip part was the highest in Litang yak.The pH value and cooked meat percentage in outer ridge and the pH value of cucumber strip parts were the highest,and the meat color value of outer ridge,b^(*)value in cucumber strip and shear force in 3 parts were the lowest in Yadin Yak.The shear force,pH value and cooked meat rate of pepper strip and cooked meat rate of cucumber strip were the highest in the outer ridge of Serda yak.The cooked meat percentage in outer ridge,L^(*)value of pepper strip and a^(*)value of cucumber strip were the lowest.The total amino acid(TAA)content of Larema yak was the highest;the essential amino acid(EAA)content of Seda yak was the highest,and the TAA and EAA contents of Litang yak were the lowest.The EAA/TAA values of Lachima yak,Yadin yak and Seda yak ranged from 38.36%to 38.96%,and the EAA/NEAA values ranged from 62.03%to 63.89%.The EAA/TAA and EAA/NEAA values of Litang yak were 35.89%and 55.84%,respectively.Yadin yak had the highest calcium content and the lowest magnesium content.Yadin yak and Seda yak had higher iron content.The zinc content of Litang yak meat was the lowest.The contents of lead,cadmium,chromium,arsenic and mercury in 4 varieties of yak meat were all lower than the national limit value.The results showed that the meat quality and nutrient composition of different yaks were different.The meat color of Lachima yak was the brightest;the meat color of yak was the tenderest;the protein quality of Lachima yak,Yadin Yak and Seda yak were higher,and the heavy metal content of the four yaks met the national standards for food safety.