不同来源ATP表征冷鲜羊肉新鲜度

【目的】通过系统研究冷鲜羊肉不同来源的三磷酸腺苷（adenosine triphosphate,ATP。包括肉中ATP、微生物ATP、肉表面ATP）在贮藏期间的变化规律,筛选能够表征冷鲜羊肉新鲜度变化的ATP指标,构建菌落总数和挥发性盐基氮预测模型,探究冷鲜羊肉新鲜度的预测新方法。【方法】以小尾寒羊背最长肌为试验材料,在空气密封包装0℃条件下分别贮藏0、1、3、5、7、9、11、13、15、17和21 d,分析冷鲜羊肉贮藏期间新鲜度指标（pH、色泽、挥发性盐基氮、菌落总数）与3种来源ATP（肉中ATP、微生物ATP、肉表面ATP）的变化,利用数据统计评价不同来源ATP的变化规律,并构建新鲜度指标的预测模型。【结果】冷鲜羊肉贮藏期间新鲜度指标菌落总数、挥发性盐基氮均呈现上升趋势,并均在贮藏17 d时超过国家标准限值;肉中ATP呈现不断下降趋势,微生物ATP与肉表面ATP均呈现上升趋势,与新鲜度指标变化趋势保持一致;冷鲜羊肉贮藏期间,肉中ATP、微生物ATP、肉表面ATP含量与菌落总数、挥发性盐基氮的相关系数（R）分别为-0.399、0.910、0.943和-0.357、0.725、0.907。肉表面ATP预测冷鲜羊肉菌落总数的最优模型为Boltzmann拟合模型,其公式为TVC（lg cfu/g）=7.649-4.069/(1+exp(x-5.807)/0.632)（R ²=0.903,P<0.001）,肉表面ATP预测冷鲜羊肉挥发性盐基氮的最优模型为Expedc1拟合模型,其公式为TVB-N（mg/100 g）=2.493*exp(x/3.745)+3.057（R ²=0.888,P<0.001）。【结论】本研究明确了冷鲜羊肉表面ATP与菌落总数、挥发性盐基氮存在显著正相关性,确证了肉表面ATP可以作为冷鲜羊肉新鲜度表征指标;并构建了菌落总数和挥发性盐基氮最优预测模型,为冷鲜羊肉新鲜度快速检测提供了新的思路。

Characterization of Chilled Mutton by ATP from Different Sources

【Objective】 In order to explore a new method for predicting the freshness of chilled mutton, the changes of adenosine triphosphate (ATP in meat, microbial ATP and ATP of meat surface) from different sources during storage were systematically studied, then the ATP that could characterize the change of chilled mutton was screened, and finally the prediction models for the total viable counts and volatile base nitrogen were established. 【Method】 The longissimus dorsi muscle of Small Tailed Han sheep was stored in air sealed packaging at 0℃ for 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, and 21 days, respectively. The freshness indexes (pH, color, volatile base nitrogen, and total viable counts) and ATP from three sources (ATP in meat, microbial ATP, and ATP of meat surface) of chilled mutton were analyzed during storage. The changes of ATP from different sources were evaluated, and the predictive models of freshness indicators were built. 【Result】 The freshness index of total viable counts and volatile base nitrogen in chilled mutton showed an upward trend during storage, and both of them exceeded the national standard limit after 17 days; the ATP in meat showed a decreasing trend, while the microbial ATP and the ATP of meat surface were increased, which was consistent with the change trend of the freshness index; the correlation coefficients (R) between ATP in meat, microbial ATP, ATP of meat surface and total viable counts, total volatile base nitrogen were -0.399, 0.910, 0.943 and -0.357, 0.725, 0.907, respectively. The optimal model for predicting the total viable counts in chilled mutton by ATP of meat surface was Boltzmann, which the formula was TVC (lg cfu/g)=7.649-4.069/(1+exp(x-5.807)/0.632), (R² =0.903, P<0.001); the optimal model for predicting total volatile base nitrogen in chilled mutton by ATP of meat surface was Expedc1, which the formula was TVB-N (mg/100 g)=2.493*exp(x/3.745)+ 3.057 (R²=0.888, P<0.001). 【Conclusion】 The results showed that the ATP of meat surface of chilled mutton had the significant positive correlations with the total viable counts and volatile basic nitrogen, and then confirmed that the ATP of meat surface could be used as an indicator to characterize the freshness of chilled mutton. The optimal prediction model of the total viable counts and volatile base nitrogen could provide a new idea for rapid detection of chilled mutton freshness.