电子鼻检测不同贮藏温度下猪肉新鲜度变化

采用电子鼻研究冷却猪肉在不同贮藏温度(－ 18、0、4、10、20℃)条件下新鲜度变化规律。选用优化后的进样体积(1500μL)进样，对实验数据进行主成分分析(PCA)、货架期模拟及拟合感官评分的偏最小二乘回归分析(PLS)。结果表明：5 种温度条件下贮藏不同时间肉样挥发性气味差异显著，贮藏温度越高肉样新鲜度发生显著下降时刻越早，预测时间分别为336、180、72、48、18h。对4、20℃条件下电子鼻检测数据与感官评分拟合后进行PLS 分析，相关系数分别高达0.9982和0.9998，表明电子鼻能代替感官评定。逐一选取每一根传感器进行PLS 拟合后发现，TA/2、T40/1、T40/2、P30/2、P40/1、P10/2、P10/1 是对不同新鲜度肉样挥发性气味具有良好特异性响应的传感器。

Electronic Nose for Measurement of Freshness Change of Chilled Pork during Storage at Different Temperatures

Electronic nose was used to measure the freshness change of chilled pork during storage at －18, 0, 4, 10 or 20 ℃. Injection volume of minced samples was optimized to be 1500 μL. Principal component analysis (PCA) of volatile odor of chilled pork was conducted. Electronic nose output signal was plotted as a function of storage time to estimate shelf-life of chilled pork stored at different temperatures. Partial least squares regression (PLS-regression) was employed to analyze correlation between electronic nose output signal and sensory evaluation score of volatile odor of chilled pork stored at 4 or 20 ℃. Results showed that there was a significant difference in volatile odor of chilled pork stored for different time at －18, 0, 4, 10 or 20 ℃. Higher storage temperature resulted in earlier occurrence of significant decrease of freshness. The shelf-life of chilled pork stored at the above temperatures was 336, 180, 72, 48 h and 18 h, respectively. The correlation coefficients between electronic nose output signal and sensory evaluation score of volatile odor of chilled pork stored at 4 and 20 ℃ were as high as 0.9982 and 0.9998, respectively, demonstrating that electronic nose is a reliable alternative to sensory evaluation for analysis of volatile odor of chilled pork. Electronic nose sensors TA/2, T40/1, T40/2, P30/2, P40/1, P10/2 and P10/1 were all found to give excellent specific responses to various characteristic odors of pork.