不同绵羊品种膻味物质分离、鉴定和比较分析

Extraction,Identification and Comparison of Mutton Flavor Materials from Different Sheep Breeds

为进一步优化4-甲基辛酸和4-甲基壬酸的测定参数和比较不同地域不同绵羊膻味物质的差异,分别采集约6月龄蒙古羊、滩羊、小尾寒羊、同羊皮下脂肪样品,用气相色谱对其分析测定。采用同时蒸馏萃取方法,设定30、45、60、75、90、1051、20 min共7个梯度的蒸馏时间以及0.05、0.10、0.25、0.50、1.02、.0 mL 6个脂肪酸样品的加入量,来确定最佳蒸馏时间和最低脂肪酸添加量对同时蒸馏萃取灵敏度的影响。结果表明,蒸馏时间为90 min、最低脂肪酸加入量为0.5 mL时,4-甲基辛酸和4-甲基壬酸的回收率最高。4个绵羊品种中,小尾寒羊的4-甲基辛酸含量最高,显著高于蒙古羊和同羊(P<0.05);滩羊的4-甲基辛酸含量显著高于蒙古羊(P<0.05);小尾寒羊与滩羊、滩羊与同羊、同羊与蒙古羊的4-甲基辛酸含量差异不显著(P>0.05)。不同地域的绵羊品种对4-甲基壬酸含量的影响差异不显著(P>0.05)。说明,在采用同时蒸馏萃取-气相色谱方法分离测定4-甲基辛酸和4-甲基壬酸时,蒸馏时间为90 min、最低脂肪酸加入量为0.5 mL时,4-甲基辛酸和4-甲基壬酸的回收率效果最好,且不同地域绵羊品种膻味物质含量有一定差异,小尾寒羊脂肪组织中4-甲基辛酸的含量最高。

This research was conducted to investigate optimal parameters for extracting,identifying,and determining 4-methyloctanoic acid and 4-methylnonanoic acid content of sheep adipose tissue and comparing the different content of mutton flavor materials in different sheep breeds raised in different regions.Samples of subcutaneous fat were collected from 4 sheep breeds raised in different regions,including Mongolian sheep（Inner Mongolia Autonomous Region）,Tan sheep（Ningxia Hui Autonomous Region）,Small Tail Han sheep（Henan province） and Tong sheep（Shaanxi province）,and analyzed by using GC.Different distillation time（30,45,60,75,90,105,120 min） and different addition amount（0.05,0.10,0.25,0.50,1.0,2.0 mL） of fatty acid were set when simultaneous distillation extraction（SDE） was adopted for determining the sensitivity of SDE.The results showed that the recovery ratio of 4-methyloctanoic acid and 4-methylnonanoic acid was the highest with the distillation time set at 90 min and the minimum addition amount set at 0.5 mL.Among the four sheep breeds,Small Tail Han sheep had the greatest content of 4-methyloctanoic acid,which was significantly higher（P0.05） than that of Mongolian sheep and Tong sheep.The content of 4-methyloctanoic acid in Tan sheep was greater（P0.05） than that in Mongolian sheep.No difference（P0.05） was found on the content of 4-methylnonanoic acid among the different sheep breeds.It could be concluded that the distillation time setting at 90 min and the minimum addition amount setting at 0.5 mL were the optimal condition for extracting,identifying and determining 4-methyloctanoic acid and 4-methylnonanoic acid by SDE-GC.Moreover,different sheep breeds raised in different regions affected the content of mutton flavor materials in sheep adipose tissue and Small Tail Han sheep had the highest content of 4-methyloctanoic acid.