基于pH值变化的冷藏草鱼肉新鲜度预测模型研究

Study on the Prediction Model of Freshness of Chilled Grass Carp Based on the Changes of pH Value

为研究冷藏草鱼肉在贮藏过程中酸度(pH值)与汁液流失率、色差值、挥发性盐基氮(total volatile basic nitrogen,TVB-N)值、硫代巴比妥酸(thiobarbituric acid,TBA)值、菌落总数等指标之间的关系及变化规律。以市售草鱼作为试验材料,切成鱼段杀菌包装,每24 h测定以上指标。试验结果表明,草鱼肉在4℃下存放10 d,每隔24 h测定的pH值和挥发性盐基氮值呈直线正相关(P<0.01),且更为客观准确,回归方程为Y=33.833X-220.44(P<0.01),决定系数R2=0.9782。通过pH计测定的pH值,可以求出挥发性盐基氮值,此模型可更为快速地测定草鱼新鲜度。

The change rules of pH value,juice loss rate,color difference,total volatile basic nitrogen value(TVB-N),thiobarbituric acid value(TBA),and total bacterial count during storage of refrigerated grass carp were studied,and the relationship between each index was also discussed.The grass carp was cut into segments and packed in germicidal packaging,and the above indexes were measured every 24 h.The results showed that the grass carp at 4℃was stored for 10 days,pH value and volatile based nitrogen were presented linear variation,every 24 h measured pH value and volatile salt based nitrogen a positive correlation(P<0.01)and was more objective and accurate,its fitting regression equation:Y=33.833X-220.44(P<0.01),the coefficient of determination was 0.9782.The pH determination of grass carp pH value can be calculated TVB-N value,determine the freshness of grass carp on the simple and rapid objective.This model can be used to determine the freshness of grass carp more quickly.