反复冻融对猪肉营养成分的影响

摘要

该试验研究了反复冻融5次对猪背最长肌肉营养成分的影响,分析猪肉冻融过程中蛋白质、脂肪、氨基酸、脂肪酸和微量元素含量的变化.结果显示,随着冻融次数的增加,猪肌肉水分、粗脂肪、粗蛋白含量均显著降低(p＜0.05);灰分含量无显著变化(p ＞0.05);WTAA、WEAA和WNEAA含量均极显著下降(p＜0.01),氨基酸组成WEAA/WTAA在40％左右,WEAA/WNEAA在60％以上;冻融处理1次的第一限制性氨基酸为Met+ Cys,其余冻融次数均为Val,必需氨基酸指数(EAAI)为73.71 ～77.42;SFA和PUFA在第1次解冻后变化不显著(p＞0.05),在第2次解冻后极显著降低(p＜0.01),而MUFA无显著变化(p＞0.05);除了必需微量元素Mn和Mo含量未发生显著变化(p＞0.05),其余元素含量均呈显著下降趋势(p＜0.05),但与冻融次数有关.因此,反复冻融会显著影响猪肉的营养价值.%Frozen storage is an important preservation method for meat and meat products.In this study,the effects of freeze-thaw cycles on the nutrient composition of pig longissimus dorsi muscle was investigated and the changes of protein,fat,amino acid,fatty acid and trace element in the process of freeze-thaw cycles were analyzed.The results showed that the contents of water,crude fat and crude protein were significantly decreased (p ＜ 0.05) with freeze-thaw cycles,and the contents of ash did not change significantly (p ＞ 0.05).WTAA,WEAA and WNEAA were significantly decreased (p ＜ 0.01),WEAA / WTAA was about 40％ and WEAA / WNEAA was more than 60％.The first limited amino acid for the first freeze-thaw treatment cycle was Met + Cys,and Val was for the rest of the cycle.The essential amino acid index (EAAI) was 73.71-77.42.SFA and PUFA did not change significantly in the first freeze-thaw (p ＞ 0.05),and decreased significantly after the second freeze-thaw (p ＜ 0.01);MUFA did not change significantly (p ＞0.05).The contents of Mn and Mo did not change significantly (p ＞ 0.05),and the contents of other trace elements were significantly decreased (p ＜ 0.05).Therefore,freeze-thaw cycle can significantly affect the nutritional value of pork.