Abstract:

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.

Key words: electronic nose, chilled pork, volatile odor, freshness, shelf-life