不同屠宰活重豫西黑猪的营养成分及肉质特性分析

Analysis of Nutrient Composition and Meat Quality Characteristics of Yuxi Black Pigs at Different Slaughter Live Weights

【目的】探讨豫西黑猪营养成分及肉质性状在不同体重阶段的发育性变化规律。【方法】选取平均体重约为60、75、90、105、120 kg 5个体重阶段的豫西黑猪,每组5头,共25头,每组随机选取3头进行屠宰,公母随机。屠宰后取背最长肌测定眼肌面积、背膘厚、脂肪率、失水率、脂肪酸、氨基酸和胆固醇等指标,测定肌内脂肪含量、脂滴直径和脂滴数目,采集100 g腰大肌测定熟肉率。【结果】豫西黑猪在体重达到120 kg之前,随着屠宰活重的增加,眼肌面积、背膘厚、脂肪率、熟肉率、肌内脂肪含量、肉色、剪切力、脂滴数目和脂滴直径均随之增加。眼肌面积在105、120 kg时均极显著高于60、75 kg(P<0.01),显著高于90 kg(P<0.05);背膘厚在90、105、120 kg时均极显著高于60 kg(P<0.01);肌内脂肪含量在90、105、120 kg时均显著高于60、75 kg(P<0.05);脂滴直径和脂滴数目在75、90、105、120 kg时均显著高于60 kg(P<0.05);脂肪酸中饱和脂肪酸以肉豆蔻酸、棕榈酸、硬脂酸等为主,不饱和脂肪酸以棕榈油酸、油酸、亚油酸等为主,氨基酸种类丰富,组氨酸、酪氨酸、缬氨酸和异亮氨酸含量在120 kg时均显著高于105 kg(P<0.05)。体重与熟肉率、粗蛋白质、肉色、粗脂肪呈极显著或显著正相关(P<0.01;P<0.05);肌内脂肪含量与大理石花纹、粗脂肪、肉色、脂滴直径呈极显著或显著正相关(P<0.01;P<0.05)。【结论】屠宰活重在120 kg时,豫西黑猪肌内脂肪含量适中,大理石花纹丰富,不饱和脂肪酸与饱和脂肪酸比例适宜,鲜味氨基酸含量增加,胆固醇含量较低,肉色鲜嫩,胴体品质和肉品质最佳。

【Objective】 This study was aimed to explore the developmental changes of nutritional components and meat quality characteristics of Yuxi Black pigs at different weight stages.【Method】 5 group Yuxi Black pigs with average body weight of 60,75,90,105 and 120 kg were selected, there were 25 in total, 5 in each group, 3 in each group were randomly selected for slaughter, male and female random.After slaughter, the longissimus dorsi muscle were collected to measure eye muscle area, backfat thickness, fat rate, water loss rate, fatty acid, amino acid and cholesterol, and determine intramuscular fat content, lipid droplet diameter and lipid droplet number.100 g psoas major muscle were used to analyze the cooked meat rate.【Result】 Before the weight of Yuxi Black pigs reached 120 kg, the eye muscle area, backfat thickness, fat percentage, cooked meat rate, intramuscular fat content, meat color, shearing force, number and diameter of fat drop increased with the increase of slaughter live weight.The eye muscle area at 105 and 120 kg were extremely significantly higher than that at 60 and 75 kg(P<0.01),and significantly higher than that at 90 kg(P<0.05).The backfat thickness at 90,105 and 120 kg were extremely significantly higher than that at 60 kg(P<0.01).The intramuscular fat content at 90,105 and 120 kg were significantly higher than that at 60 and 75 kg(P<0.05).The diameter and number of lipid droplets at 75,90,105 and 120 kg were significantly higher than those at 60 kg(P<0.05).The main saturated fatty acids were myristic acid, palmitic acid and stearic acid, while the main unsaturated fatty acids were palmitic acid, oleic acid and linoleic acid.There were abundant types of amino acids, and the contents of histidine, tyrosine, valine and isoleucine at 120 kg were significantly higher than those at 105 kg(P<0.05).The body weight was extremely significantly or significantly positively correlated with cooked meat rate, crude protein, meat color and crude fat(P<0.01 or P<0.05).The intramuscular fat content was extremely significantly or significantly positively correlated with marbling, crude fat, meat color and lipid droplet diameter(P<0.01 or P<0.05).【Conclusion】 When the slaughter live weight up to 120 kg, the intramuscular fat content was moderate, the marbling pattern was rich, the ratio of unsaturated fatty acid to saturated fatty acid was suitable, the content of umami amino acid was increased, the content of cholesterol was lower, the meat color was fresh and tender, and the carcass quality and meat quality were the best.