冷却方式对宰后分割牛肉肉用品质的影响

Effects of Cooling Methods on Quality of Beef Cuts after Slaughtering

[目的]研究不同冷却方式对宰后分割牛肉品质的影响,为改善牛肉嫩度,增强食用品质提供理论依据。[方法]以宰后分割牛肉为材料,用快速冷却、常规冷却、延迟冷却3种冷却方式对宰后分割牛肉进行处理,于4℃冷库成熟7 d,考察各冷却方式对牛肉品质的影响。[结果]经快速冷却处理的分割牛肉由于降温速度快,2 h温度降至4℃左右时,p H高于6.2,出现肌肉冷收缩现象,剪切力最大,在成熟过程中嫩化效果不佳(P>0.05),且对肉色影响不大。常规冷却的牛肉降温速率仍较快,且冷却失重较大。延迟冷却后的牛肉因温度较高,可以促进牛肉进入僵直期,随着成熟的进行牛肉的嫩度不断增大,亮度和红度得到改善,虽然冷却损失较快速冷却的牛肉大,但牛肉的嫩度改善程度最大,牛肉的食用品质最佳。[结论]延迟冷却很大程度上改善了牛肉嫩度,增强了牛肉食用品质。

[Objective] To study the effects of different cooling methods on the quality of beef cuts after slaughtering,and provide theoretical basis for improving the beef tenderness and edible quality. [Methods] Taking beef cuts after slaughtering as materials,treatment was carried out by rapid cooling,conventional cooling and delayed cooling to maturate for 7 days at a 4 ℃ cold storage,to evaluate the effects of cooling methods on quality of cut beef. [Results] Due to rapid cooling,the temperature of beef cuts treated by rapid cooling process dropped to 4 ℃in 2 h,p H was higher than 6. 2,cold shrinkage occurred,and shear stress was up to the maximum. The tenderizing effect on beef cuts was not significant during the maturation process（ P 0. 05）,and the effect on cuts color was weak. The cooling speed of beef cuts treated by conventional cooling was still rapid,and beef cuts suffered a large weight loss. Due to the high temperature,the beef cuts treated by delayed cooling entered into stiff stage quickly. Along with the maturity of beef,the tenderness increased,and the lightness and red degree improved. Although the weight loss of beef cuts was greater than the rapid cooling process,the improvement of beef tenderness and consumption quality got up to the maximum. [Conclusion] The beef tenderness and edible quality are both improved by delayed cooling.