两种放牧方式对绒山羊肉抗氧化系统的影响

Effects of Two Grazing Conditions on Antioxidant Defense System in Cashmere Goat Meat

以草场放牧、山地放牧两种方式下的绒山羊背最长肌为实验材料,测定背最长肌的色泽、肌红蛋白含量、丙二醛含量、氧合肌红蛋白相对含量、高铁肌红蛋白相对含量、抗氧化酶活力和总抗氧化能力等指标并进行比较分析。结果表明:草场放牧绒山羊肉的红度、过氧化氢酶活力、谷胱甘肽过氧化物酶活力和自由基清除率均显著高于山地放牧(P<0.05);草场放牧绒山羊肉亮度、黄度、高铁肌红蛋白相对含量、丙二醛含量均显著低于山地放牧(P<0.05),但两种放牧方式绒山羊肉的肌红蛋白含量、氧合肌红蛋白相对含量、超氧化物歧化酶活力和总抗氧化能力没有显著差异(P>0.05)。在草场放牧条件下,绒山羊能摄食大量绿色牧草,并且有适宜的运动量,增加了抗氧化酶的活力和肉色稳定性,自由基的产生和清除达到了平衡,从而使其肉品的抗氧化能力高于山地放牧。

The objective of this study was to investigate the differences in the color, myoglobin（Mb）, malondialdehyde（MDA）, oxymyoglobin（OMb） and metmyoglobin（MMb） contents, antioxidant enzyme activities and total antioxidant capacity of longissimus dorsi muscle（LDM） from cashmere goats subjected to two grazing conditions（pasture and mountainside）. The results showed that redness value, catalase and peroxidase activity and radical scavenging capacity of LDM from pasture-grazed goats were significantly higher than those of mountainside-grazed goats（P〈0.05）, while lightness value, yellowness value, and MMb and MDA contents of LDM from pasture-grazed goats were significantly lower（P〈0.05）. However, as far as Mb and OMb contents and superoxide dismutase activity in goat meat were concerned, no significant difference existed between two grazing conditions（P〉0.05）. Consequently, the meat from pasture-grazed goats had higher antioxidant capacity than the mountainside-grazed goats due to the consumption of abundant amounts of green herbage and appropriate exercise, which helped improve antioxidant enzyme activities and meat color stability and maintain the balance between the generation and scavenging of free radicals.