负向近冰点温度下绵羊宰后肌肉主要理化指标变化

以宰后未经速冷处理的绵羊左后大腿为对照组,以宰后经过6h速冷处理的绵羊左后大腿为处理组,在-1～1℃贮存,并对其3～216h内肌肉中糖原、巯基、pH、失水率、游离钙离子浓度、游离氨基酸、游离羟脯氨酸的变化进行了研究。结果表明,在宰后3～216h内处理组的糖原含量、pH、失水率始终显著(P<0.05)高于对照组;处理组巯基含量始终稍低于对照组,游离羟脯氨酸含量处理组稍低于对照组,但差异不显著;游离钙离子浓度、游离氨基酸含量宰后3～48h先下降随后逐渐升高到最大值后转为下降的(p<0.05)变化规律基本一致。并且得出了部分相应的相关方程。利用主成分分析及METLAB软件对肉样的七项指标进行分析可知,在3～216h内糖原含量、pH、失水率、巯基含量、游离氨基酸含量等对肌肉僵直化进程起着重要的作用。所测定的肉样在宰后9h就进入了僵直起始阶段,在宰后48h僵直结束。

Changes of biochemical properties of sheep muscle stored at the temperature close to cryoscopic point

Changes of level of glycogen,sulfhydryl group,pH value,water depletion,free calcium,free amino acid and free hydroxyproline of muscle sample collected from left legs of sheep muscle after slaughter were studied.The samples were divided into two groups.One was the control group stored at the temperature of-1～1℃.The other,the treatment group,treated with-25℃ for 6 hours,then stored at the temperature of-1～1℃.Both of the control group and the treatment group were observed for 216 hours.The results showed that the glycogen concentrations,pH,water depletion rate of the treatment group were significantly higher than the control group(P<0.05);the level of sulfhydryl group of the treatment group was slightly lower than the control group.The free hydroxyproline of the treatment group was slightly lower than the control group.The variation of free calcium concentration and free amino acid of the two groups was much similar.The principal component analysis and METLAB were conducted to indicate influence of properties on rigor setting.Based on the contribution to the rigor setting,the glycogen concentration,level of sulfhydryl group,pH value,water depletion rate and free calcium concentration showed strong influence on the procedure.The rigor mortis stated at the 9th hour after slaughter,and ended at the 48th hour.