去势与未去势空山牛肌肉中氨基酸差异分析

Analysis of Amino Acids Differences in the Muscles of Castrated and Uncastrated Kongshan Cattle

中文关键词: 空山牛  牛肉营养成分  牛肉氨基酸含量

英文关键词: Kongshan cattle  nutritional composition of beef  amino acid content in beef

中文摘要:

      分析未去势空山牛和去势空山牛肌肉中氨基酸含量、组成及其分布特点，客观评价其肉品质，为巴中市乃至四川地方黄牛开发利用及牛肉产品的深加工提供科学依据。试验选取 48 月龄的健康未去势空山牛和去势空山牛各 3 头进行屠宰，采集上脑、眼肉、里脊、外脊、辣椒条、米龙、大黄瓜条、小黄瓜条、臀肉、牛霖、胸肉、腹肉、腱子共 13 个部位的肉样，测定其基本营养成分和氨基酸含量，并以联合国粮农组织（FAO）和世界卫生组织（WHO）提出的氨基酸模式为标准进行营养价值评价。结果表明，未去势空山牛和去势空山牛不同部位中粗蛋白质平均含量在 20% 左右，腹肉中粗脂肪含量最高；各部位肌肉中氨基酸含量丰富，未去势空山牛的总氨基酸（TAA）、必需氨基酸（EAA）和非必需氨基酸（NEAA）含量分别达 18.88%、7.45% 和 11.43%，去势空山牛的 TAA、EAA 和 NEAA 分别达 17.37%、6.85% 和 10.49%；未去势空山牛和去势空山牛 EAA/TAA、EAA/NEAA 平均值分别为 39.43%、65.14% 和 39.41%、65.23%，基本符合 FAO/WHO 理想蛋白质模式要求；3 种呈味氨基酸在各部位肌肉中均有分布，分布规律为苦味氨基酸 > 甜味氨基酸 > 鲜味氨基酸，未去势空山牛和去势空山牛中苦味氨基酸占总氨基酸比值高达 39.85% 和 39.65%；各部位肌肉中人体必需氨基酸营养价值评价显示，未去势空山牛和去势空山牛 7 种必需氨基酸评分均高于 FAO/WHO 氨基酸评分标准，其中苏氨酸、异亮氨酸和赖氨酸评分均高出 FAO/WHO 标准模式 2 倍及以上。综上可知，空山牛牛肉蛋白质组成较好，营养价值较高，可作为优质蛋白质来源。

英文摘要:

      This study aimed to analyze the content, composition, and distribution characteristics of amino acids in the muscles of uncastrated and castrated Kongshan cattle, to objectively evaluate their beef quality, and to provide scientific basis for the development and utilization of local yellow cattle breeds in Bazhong City and Sichuan Province, as well as for the deep processing of beef products. The experiment selected three healthy 48-month-old uncastrated Kongshan cattle and three castrated Kongshan cattle, and samples from 13 muscle parts (chuck, ribeye, tenderloin, strip loin, blade, topside, silverside, eye of round, rump, knuckle, brisket, flank, and shank). The basic nutritional components and amino acid content were determined, and the nutritional value was evaluated based on the amino acid pattern proposed by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). The results showed that: the average crude protein content in different muscle parts of uncastrated and castrated cattle was approximately 20%, with the highest crude fat content found in the flank. All muscle parts were rich in amino acids. The total amino acids (TAA), essential amino acids (EAA), and non-essential amino acids (NEAA) content in uncastrated Kongshan cattle reached 18.88%, 7.45%, and 11.43%, respectively, while those in castrated Kongshan cattle were 17.37%, 6.85%, and 10.49%. The ratios of EAA/TAA and EAA/NEAA in uncastrated and castrated cattle averaged 39.43%, 65.14% and 39.41%, 65.23%, respectively, aligning with the FAO/WHO ideal protein model. Three flavor-related amino acids were distributed across all muscle parts, with the order: bitter amino acids > sweet amino acids > umami amino acids. Bitter amino acids accounted for 39.85% and 39.65% of TAA in uncastrated and castrated Kongshan cattle, respectively. Nutritional evaluation of essential amino acids revealed that the scores of seven EAAs in both groups exceeded FAO/WHO standards, with threonine, isoleucine, and lysine scores surpassing the standard by twofold or more. In conclusion, Kongshan beef exhibits excellent protein composition and high nutritional value, serving as a premium protein source.