宰后成熟对湖羊肉品质的影响

Effect of Maturation Time After Slaughter on Meat Quality in Hu Sheep

为探究宰后成熟对湖羊肉品质及肌纤维形态的影响,筛选湖羊肉最佳宰后成熟时间,本试验选取6只8月龄湖羊公羊,取背最长肌分别在4℃下成熟0、12、24、36、48、72、96、120、144、168 h时,测定pH值、剪切力、保水能力、挥发性盐基氮(TVB-N)和肉色;在4℃下成熟0、12、24、48、72 h时,测定肌纤维形态。结果显示,宰后成熟过程中,羊肉的剪切力值先上升后下降,嫩度得到了极大改善;保水能力先下降后上升;TVB-N含量持续上升;肌纤维逐渐变得松散,骨架蛋白最终几乎全部断裂。湖羊肉在宰后0~24 h pH值显著下降(P<0.05);12 h时肌纤维骨架蛋白盘曲折叠,24 h时肥大肿胀,肌纤维骨架蛋白空间结构的变化导致肉质变硬,剪切力显著上升(P<0.05),并于24 h时达到最大值;48 h时肌纤维骨架蛋白开始断裂,剪切力显著下降(P<0.05);0~72 h内肌纤维直径不断减小、细胞间隙不断增大,肌肉蒸煮损失率与失水率呈上升趋势,72 h后剪切力变化不显著(P>0.05);72 h时L*值(亮度值)达到最大,此时肉色最亮;TVB-N含量不断上升,并于120 h时超过国家一级鲜肉的标准,肉质变得不新鲜,建议存储时间以72 h为宜,不超过96 h。综合来看,湖羊肉在宰后72 h时嫩度较好,肉色最亮,且符合国家一级鲜肉标准,但此时肉的保水能力较差。

The purpose of this study is to investigate the effect of post slaughter maturation time on the meat quality and muscle fiber morphology in Hu sheep,and to screen for the optimal post slaughter maturation time for Hu sheep meat.Six 8-month-old male Hu sheep were selected for this experiment,and the longissimus dorsi was collected after slaughter.pH,shear force,water holding capacity,total volatile basic nitrogen(TVB-N),and meat color were measured after maturing of the longissimus dorsi at 4℃for 0,12,24,36,48,72,96,120,144,and 168 hours.And after maturation at 4℃for 0,12,24,48,and 72 hours,the morphology of muscle fibers was measured.The results showed that du-ring the maturation process after slaughter,the shear force value of lamb meat first increased and then decreased,and the tenderness was greatly improved;the water retention capacity first decreased and then increased;the TVB-N content continued to rise;the muscle fibers gradually became loose,and the skeleton proteins eventually broke almost completely.The pH of Hu sheep meat significantly decreased within 0-24 hours post-slaughter(P<0.05).At 12 hours,the skeletal proteins of muscle fibers exhibited folding and twisting,while at 24 hours,they became enlarged and swollen.The changes in the spatial structure of muscle fiber skeleton proteins led to a hardening of the meat texture,with shear force significantly increasing(P<0.05)and reaching its peak at 24 hours.At 48 hours,the muscle fiber skeleton protein began to break and the shear force significantly decreased(P<0.05).Within 0-72 hours,the diameter of muscle fibers continuously decreased and the intercellular space continuously increased,the muscle cooking loss rate and drip loss showed an upward trend.And the shear force change was not significant after 72 hours(P>0.05).At 72 hours,the L*value reached its maximum,indicating the brightest red color of the meat.The TVB-N content continued to increase and exceeded the national standard for first-class fresh meat at 120 hours,causing the meat to become stale.It is recommended to store for 72 hours,not exceeding 96 hours.In conclusion,the meat tenderness of Hu sheep is better at 72 hours post-slaughter,exhibiting the brightest red color and meeting the national standard for first-grade fresh meat,although its water retention capacity is relatively poor at this stage.