温度波动对冷却猪肉品质的影响

本文以宰后24 h猪背最长肌为研究对象,研究在4 ℃、0和4 ℃各2 h、4和8 ℃各2 h条件下冷藏0、24、48和72 h对pH、色差、冷藏损失率、蒸煮损失率、剪切力和水分分布状态的影响。结果表明,pH、b*值、冷藏损失率和蒸煮损失率随着冷藏时间的延长显著升高(p<0.05),剪切力显著降低(p<0.05);提高波动温度,pH、b*值、冷藏损失率和蒸煮损失率显著增加(p<0.05),剪切力显著降低(p<0.05)。低场核磁共振结果显示随着冷藏时间增加,T_2b、T₂₁和T₂₂的起始弛豫时间显著延长(p<0.05),P₂₁的峰面积比例降低,P₂₂的峰面积比例增加;降低波动温度,T_2b、T₂₁和T₂₂起始弛豫时间显著降低(p<0.05),P₂₁的峰面积比例升高,P₂₂的峰面积比例减少。综上所述,4、0和4 ℃各2 h冷藏保存有利于冷却肉品质的保持。

Effect of Temperature Fluctuation on the Quality of Chilled Pork

In this paper,the pork longissimus dorsi after 24 h slaughter as raw material,through the analysis of the pH,color,storage loss rate,cooking loss rate,shearing force and low-field nuclear magnetic resonance with different storage times( 0,24,48 and 72 h) and temperature( 4 ℃,0 and 4 ℃ each for 2 h,4 and 8 ℃ each for 2 h).The results showed that: The pH,b*values,storage loss rate and cooking loss rate of the pork longissimus dorsi increased significantly( p < 0.05) with the increasing of storage time,but the shear force decreased significantly( p < 0.05). The pH,b*values,storage loss and cooking loss also increased significantly( p < 0.05) with the increasing of temperature fluctuation,then the shear force decreased significantly( p < 0.05). The result of low field nuclear magnetic resonance technology found that: The T2b,T21 and T22 relaxation times were longer significantly( p < 0.05) with increasing storage time,the peak ratios of P21 were lowered,and the peak ratios of P21 were increased.The T2 b,T21 and T22 relaxation times were shorter significantly( p < 0.05) with the decreasing of storage temperature and temperature fluctuation,the peak ratios of P21 were increased,and the peak ratios of P22 were lowered. To sum up,the quality of the pork longissimus dorsi would be conducive to maintain when the chilled storage at 4,0,4 ℃ for 2 h each.