宰后贮藏过程中羊肉品质变化

Changes in Quality of Mutton during Post-Slaughter Storage

为研究宰后羊肉贮藏过程中的品质变化,本试验选取湖羊背脊作为研究对象,对其挥发性盐基氮(TVB-N)、肉色、pH值、保水性、剪切力、肌原小片化指数(MFI)、脂肪酸等指标进行测定分析。结果表明:羊肉亮度值(L^(*))和红度值(a^(*))随宰后时间的延长呈先上升后下降的趋势,黄度值(b^(*))则呈先上升后趋于稳定的趋势,氧合肌红蛋白相对含量与a^(*)变化规律一致;宰后羊肉的pH值随着贮藏时间的延长先下降后逐渐升高,36 h时pH值最低,为5.30,60 h后无显著变化;宰后36 h羊肉的蒸煮损失和滴水损失最高,随后减少;羊肉剪切力呈现先上升后下降趋势,宰后36 h达到最大,MFI值呈上升趋势;湖羊背最长肌中共检测出24种脂肪酸,其中有11种SFA、8种MUFA和5种PUFA;随着贮藏时间的延长,SFA和MUFA的相对含量无明显变化,PUFA的相对含量呈现先下降后升高再下降的趋势,60 h达到最大值。综上,随着宰后贮藏时间的延长,羊背最长肌从0 h开始进入僵直到第36小时达到最大,60 h湖羊肉具有较好的加工和食用品质。本试验结果可为湖羊肉生产中品质形成控制技术提供理论指导。

In order to study the quality change of mutton during post-slaughter storage,the back ridge of Hu sheep was selected as test material,and the volatile base nitrogen(TVB-N),meat color,pH value,water retention,shear force,myofibrillar index(MFI),fatty acid and other indicators were measured and analyzed.The results showed that the brightness value(L^(*))and redness value(a^(*))of mutton increased first and then decreased with the prolongation of post-slaughter time,while the yellowness value(b^(*))increased first and then stabilized.The change of relative content of oxymyoglobin was consistent with the change rule of a^(*).The pH value of mutton after slaughter decreased first and then increased gradually with the prolongation of storage time,which was the lowest as 5.30 at 36 h and had no significant change after 60 h.The cooking loss and drip loss of mutton were the highest at 36 h after slaughter,and then decreased.The shear force of mutton increased first and then decreased,and reached the maximum at 36 h after slaughter.The MFI value showed an upward trend.A total of 26 kinds of fatty acids were detected in the longissimus dorsi muscle of Hu sheep,including 11 kinds of saturated fatty acids(SFA),8 kinds of monounsaturated fatty acid(MUFA)and 5 kinds of polyunsaturated fatty acid(PUFA).With the extension of maturation time,the relative content of SFA and MUFA did not change significantly,while that of PUFA decreased first,then increased and decreased again,which reached the maximum at 60 h after slaughter.In summary,with the extension of post-slaughter storage time,the longissimus dorsi muscle of sheep began to stiffen from 0 h and reached the maximum at 36 h;until 60 h,it began to de-stiffen,and then the mutton meat had better processing and edible quality.These results could provide theoretical guidances for quality control technology in Hu mutton production.