Evaluation of Freshness in Determination of Volatile Organic Compounds Released from Pork by HS-SPME-GC-MS

Freshness is an important parameter for evaluating the quality of pork, which has strong correlation with the characteristic volatile organic compounds (VOCs) in meat. In this study, the pork was stored at a refrigerator, and the VOCs were determined by using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results of HS-SPME-GC-MS measurements were compared to total viable counts, total volatile basic nitrogen, and pH value to determine possible volatile spoilage markers. The pork was stored in a refrigerator up to 5 days at 4 A degrees C and 466 days at -18 A degrees C. The pork became stale at 4 A degrees C when the 2,3-butanedione, 3-methyl butyraldehyde, 3-methyl-1-butanol, and acetoin increased to 26.44, 13.72, 71.56, and 340.48 mu g/L, respectively. These substances can be seen as characteristic compounds of stale pork. The VOCs such as ethyl acetate, ethyl propionate, ethyl butyrate, and ethyl hexanoate had negative correlation (P < 0.05) with the pork freshness, which can be potentially considered as characteristic compounds of fresh pork. Therefore, the selected VOCs can be used as indicators for evaluation of pork freshness, and VOCs could be potentially applied in the development of intelligent refrigerators and refrigerated storehouse.