不同冷却方式对冷鲜鸡肉品质的影响

目的 探究不同冷却方式对鸡肉水分分布、蛋白质变性等理化性质的影响.方法 分析风冷、真空冷却和浸没式真空冷却对鸡肉的冷却速率、pH、色差、质构等指标的影响,通过低场核磁共振和差式扫描量热技术分析冷却后鸡肉中水分分布和肌蛋白的变化.结果 风冷的冷却速率最慢,肉色暗沉,且质量损失率高,硬度和剪切力也较大;真空冷却的冷却速率最快,肉色较为鲜艳,其质量损失率、硬度和剪切力也最大;浸没式真空冷却能有效减小鸡肉的质量损失率(P<0.05),肉色最鲜艳,弹性和回复性也最好.通过差式扫描量热法分析可知,3种冷却方式下肌蛋白的变性焓均减小,风冷组的肌球蛋白、肌浆蛋白和肌动蛋白降解最多,真空冷却组的蛋白降解较风冷组更好,浸没式真空冷却组的蛋白降解最小,与对照组无显著差异;由低场核磁共振分析可知,风冷组不易流动水组分显著降低(P<0.05),自由水显著增加(P<0.05),真空冷却自由水组分显著降低(P<0.05),浸没式真空冷却后鸡肉中水分分布与对照组无显著差异.结论 浸没式真空冷却弥补了真空冷却不足,在一定程度上提高了鸡肉品质.

Effects of Different Cooling Methods on the Qualities of Chicken Meat

In order to improve the quality of food freezing, it is necessary to optimize the structural size and internal flow field of impact freezer to optimize its freezing efficiency. Four factors influencing the heat transfer characteristics of the freezer, namely nozzle shape and size, arrangement of jet impingement, variation of nozzle to conveyor belt distance and nozzle spacing, and freezer import and export pressure were reviewed. By reviewing the cases of of CFD technology and experimental research in these four aspects of heat transfer optimization of freezer, the law of heat transfer in this kind of freezer was summarized. This study provides a theoretical support for the optimal design of the new quick freezer.