不同年龄梅花鹿肌内脂肪沉积规律及其对风味品质影响

Study on the Pattern of Intramuscular Fat Deposition and Differences Its Influence in Flavor Quality of Sika Deer at Different Ages

旨在揭示不同年龄段梅花鹿肌内脂肪沉积规律,研究肌内脂肪含量对风味品质的影响。分别选取2、3、4岁梅花鹿母鹿,检测不同年龄段梅花鹿肌肉组织特性,并根据肌内脂肪(intramuscular fat, IMF)含量将样品分为高IMF组(IMFH组)和低IMF组(IMFL组),分析其对肌苷酸、脂肪酸含量以及脂肪酸结合蛋白4(FABP4)、脂肪酸合成酶(FASN)、甾醇调节元件结合转录因子1(SREBF1)和乙酰辅酶A羧化酶(ACACA)4种基因表达量。结果表明,梅花鹿肌内脂肪含量随年龄增长逐渐增加(P<0.001),里脊肌内脂肪含量最高(P<0.001),前腱子含量最低(P<0.001);梅花鹿年龄越长,肌纤维密度显著降低(P<0.05),肌苷酸、棕榈油酸(C16:1)、C18脂肪酸、饱和脂肪酸和单不饱和脂肪酸含量显著增高(P<0.05);高肌内脂肪样本肌纤维面积显著高于低肌内脂肪样本(P<0.05),IMFH组4岁龄梅花鹿肌束内肌纤维根数和肌苷酸以及3岁龄梅花鹿C16:1、C18:1和C18:3含量高于IMFL组(P<0.05),肌纤维密度高于IMFL组。油酸(C18:1)和亚麻酸(C18:3)含量高于低肌内脂肪样本(P<0.05);FABP4和SREBF1基因表达量显著高于低肌内脂肪样本(P<0.05),肌内脂肪与多不饱和脂肪酸呈负相关(P<0.05),与单不饱和脂肪酸呈正相关(P<0.05)。综上所述,梅花鹿随年龄增长,肉质嫩度降低,风味物质含量增加,高肌内脂肪组肉质更嫩,FABP4、FASN、SREBF1和ACACA四种基因高效表达和单不饱和脂肪酸含量对肌内脂肪沉积有促进作用。

The aim of this experiment was to reveal the intramuscular fat deposition pattern of sika deer at different ages,and to study the effect of intramuscular fat content on flavor quality.The main tests were Deer at 2,3,4 years old were selected to detect the muscle tissue characteristics,then according to the content of intramuscular fat(IMF)the samples were divided into high IMF group(IMFH group)and low IMF group(IMFL group),to determine its effect on inosinic acid and fatty acid content,and to analyze the expression of four genes,namely,fatty acid binding protein 4(FABP 4),fatty acid synthetase(FASN),sterol regulatory element-binding transcription factor 1(SREBF 1),and acetyl-coenzyme A carboxylase(ACACA)expression of four genes.The results showed that the intramuscular fat content of sika deer increased gradually with age(P<0.001),with the highest intramuscular fat content in the ligamentum teres(P<0.001)and the lowest content in the anterior tendon(P<0.001);As the age of the sika deer grows,the diameter and number of roots of the muscle fibers increased significantly(P<0.05),the density of the muscle fibers decreased significantly(P<0.05),and the contents of myosinic acid,palmitoleic acid(C16∶1),C18 fatty acids,saturated fatty acids and monounsaturated fatty acids content increased significantly(P<0.05);Myofiber diameter area and stearic acid(C18∶0)were slightly lower was significantly higher in the high intramuscular fat samples than in the low intramuscular fat samples(P<0.05).The number of myofiber roots and the content of myosinic acid at 4-year-old,myofiber density,myosinic acid,C16∶1,oleic acid(C18∶1),and linolenic acid(C18∶3)content at 3-year-old in IMFH group were higher than that in the low intramuscular fat samples(P<0.05),while thy myofiber density was nighen;FASN and ACACA gene expression was slightly higher in high intramuscular fat samples than in low intramuscular fat samples(P>0.05),FABP 4 and SREBF 1 gene expression was significantly higher than in low intramuscular fat samples(P<0.05),and intramuscular fat was negatively correlated with polyunsaturated fatty acids(P<0.05)and positively correlated with monounsaturated fatty acids(P<0.05).In this experiment,it was concluded that the meat tenderness of sika deer decreased with age and the content of flavor substances increased,the higher the intramuscular fat content,the more tender the meat,and the efficient expression of four genes,FABP4,FASN,SREBF 1 and ACACA,and the content of monounsaturated fatty acids had a promotional effect on the deposition of intramuscular fat.