不同贮藏温度市售热鲜牛肉新鲜度变化研究

为了探究不同贮藏温度对市售热鲜牛肉新鲜度的影响，试验以市售热鲜牛肉为研究对象（采自4头锦江黄牛背最长肌），测定其在不同贮藏温度（5、15、25和35℃）和相对湿度（relative humidity，RH）为80%条件下，pH、L^*、a^*、b^*值、菌落总数、硫代巴比妥酸（thiobarbituric acid reactive substances，TBARS）和挥发性盐基氮（total volatile basic nitrogen，TVB-N）含量随贮藏时间（0、6、12、24、48、72、96和120 h）的变化情况。结果表明，随着贮藏时间延长，不同贮藏温度处理组热鲜牛肉的pH均呈先降低后上升的趋势，L^*、a^*和b^*值呈先上升后降低趋势，菌落总数、TBARS和TVB-N含量呈上升趋势；且贮藏温度越高，各指标随时间变化的趋势加剧。综合分析各指标的变化规律，为了保证热鲜牛肉的新鲜度和食用安全性，在5、15、25和35℃下贮藏的热鲜牛肉，其货架期分别不能超过96、72、24和12 h。

Study on Freshness Changes of Retailed Hot Fresh Beef at Different Storage Temperature

In order to investigate the freshness changes of retailed hot fresh beef at different storage temperature,Four Jinjiang cattle was selected and the longissimus dorsi were placed at 5,15,25 and 35℃ with relative humidity (RH) 80%.The change of pH,L^*,a^*,b^*,aerobic plate count,thiobarbituric acid reactive substances (TBARS),total volatile basic and nitrogen(TVB-N) value during different storage time (0,6,12,24,48,72,96 and 120 h) were analyzed.The results showed that,with the extension of storage time,the pH was decreased first and increased later.L^*,a^* and b^* values were increased first and decreased later,the number of aerobic plate count,TBARS and TVB-N values all increased during the whole storage period at the diffident storage temperature,and the higher the storage temperature,the faster the variation trend of the related indexes would be.In conclusion,in order to ensure the freshness and safety of the retailed hot fresh beef,the shelf life of fresh beef placed at 5,15,25 and 35℃ should not be exceed 96,72,24 and 12 h,respectively.