包装方式对黄羽肉鸡液氮速冻降温速率的影响

Effect of Packing Method on Rate of Temperature Fall of Liquid Nitrogen Quick-freezing of Y ellow-feather Broilers

液氮速冻是近年来快速发展起来的肉与肉制品速冻方式,为促进液氮速冻技术在黄羽肉鸡屠宰加工生产中的应用,试验对不同包装方式黄羽肉鸡胴体液氮速冻的降温曲线、降温速率、液氮速冻肉鸡的品质进行了测定分析。结果显示:在-70℃箱式液氮速冻条件下,所有包装形式的肉鸡胴体在开始冷冻过程,会呈现先升温,再下降,经过最大冰晶形成区的温度带后,快速降温到-18℃;无包装、普通包装和贴体包装肉鸡达到和通过-1℃→-5℃的时间差异显著(P<0.05);无包装样品冻结速率显著优于其他2种包装样品。无包装肉鸡在液氮速冻时冻结损失率显著高于带包装肉鸡,贴体包装的滴水损失率高于普通包装肉鸡,但蒸煮损失率优于普通包装肉鸡。综合冻结损失和鸡肉品质,贴体包装优于其他两种包装形式。

Liquid nitrogen quick-freezing is a rapidly developing method for quick-freezing meat and meat products in recent years. In order to promote the application of liquid nitrogen quick-freezing technology in yellow-feather broiler slaughtering and processing, the experiment was conducted to analyzs the cooling curve, cooling rate and quality of yellow-feather broilers in different packaging methods. The results showed that under -70 ℃ box-type liquid nitrogen quick-freezing conditions, broiler carcasses in all packaging methods showed a trend of rising, then dropped, and then rapidly cooled down to -18 ℃ after passing through the temperature zone of the maximum ice crystal formation during the freezing process.The time for reaching and passing -1℃ to -5℃ differed significantly for unpackaged, normal-packaged and skin packaging broilers(P<0.05). The freezing loss rate of unpackaged broilers was significantly higher than packaged broilers during the liquid nitrogen freezing process, and the drip loss rate of unpackaged broilers was higher than normalpackaged broilers, the cooking loss rate of skin packaging broilers was lower than normal-packaged broilers. Combining freezing loss rate and chicken quality, the skin packaging method was superior to the other two packaging methods.