冷冻对香猪组织和器官中脂类成分的影响研究

Effect of Frozen Storage on Lipid Composition in Different Tissues and Organs of Mini-pig

为了探明冷冻贮藏对香猪组织和器官中脂类成分的影响,本研究选择3头相同日龄的香猪,选取皮下脂肪、背最长肌及肝脏组织为实验样品,分析冷冻贮藏前后样品的脂肪含量、脂肪与脂肪酸组成、丙二醛含量(TBARS值)。结果显示:冷冻贮藏对各组织的脂肪含量无明显影响;贮藏后皮下脂肪、肌肉和肝脏的磷脂含量均显著下降(P<0.01),其中以肝脏的磷脂含量下降幅度最大(从45.61%下降至34.96%);皮下脂肪、肌肉和肝脏中游离脂肪酸的含量贮藏以后分别增加到原来的6.6倍、7.7倍和9.1倍。-18℃冷藏150d后,各样品的脂肪酸组成差异明显,但中性脂肪的饱和脂肪酸含量都显著升高(P<0.01),而磷脂的多不饱和脂肪酸含量则显著下降(P<0.01),游离脂肪酸的饱和脂肪酸含量大幅度降低(P<0.01)。皮下脂肪、肌肉和肝脏的TBARS值分别为0.7、16.7、120.5mg/kg,且3种组织间差异显著(P<0.01)。研究结果表明,冷冻贮藏中饱和脂肪酸的水解速度相对较慢,而不饱和脂肪酸有大量水解。冷冻贮藏过程中肝脏的脂肪组分最容易发生氧化,其次是肌肉中的脂肪,而皮下脂肪的氧化稳定性最高。

In order to investigate the effect of frozen storage on lipid composition in different tissues and organs of mini-pig,subcutaneous fat,longissimus dorsi muscle and livers from three mini-pigs of the same age were subjected to frozen storage at-18℃for 150 days.Pre-and post-storage samples were determined for their lipid content,lipid composition,fatty acid composition and malonaldehyde content.No obvious change in the lipid content of all the tested tissues and liver before and after storage was observed.However,phospholipid content exhibited a significant decrease （P〈0.01） in all the samples and the biggest decrease （from 45.61% to 34.96%） in the liver of mini-pig was observed.After 150 days of frozen storage,subcutaneous fat,muscle and liver tissues showed 6.6-,7.7-and 9.1-fold increases in fatty acid contents,respectively.In addition,an obvious difference of fatty acid compositions was observed among different tissues.The content of saturated fatty acids （SFA） in neutral lipid increased （P〈0.01）,whereas that of polyunsaturated fatty acids in phospholipid decreased （P〈0.01）,and that of saturated fatty acids decreased to the largest extent （P 0.01）.The TBARS values of subcutaneous fat,muscle and liver tissues were 0.7,16.7 mg/kg and 120.5 mg/kg,respectively,which revealed a significant difference （P〈0.01）.The above results also suggested that the lipolysis of SFA was slower than that of non-SFA during frozen storage.Lipids in liver were the most susceptible to oxidation,followed by those in muscle,and the oxidative stability of subcutaneous fat was the best under the condition of frozen storage.