Abstract: The application of pork fat oxidized by dual enzyme method for improving the flavor of natural pork essence was explored in this work. The optimal enzymatic reaction conditions for preparing oxidized pork fat, as determined using one-factor-at-a-time and orthogonal array design methods based on peroxide value (PV), were 300 μL of lipase, 400 μL of lipoxygenase and pH 8.88. Sensory evaluation revealed that pork essence based on oxidized pork fat obtained from enzymatic oxidation had a full aroma and outstanding characteristic flavor of porcine fat as compared with pork essences prepared from air-oxidized or non-oxidized pork fat. The results of solid phase microextraction coupled with gas chromatography-mass spectrometry (SPME/GC-MS) analysis indicated that these three pork essences had the same major flavor components, which included 1-(2-furanyl)-ethanone, 5-methyl-2-thiophenecarboxaldehyde, 3-methyl-thiophene, 2-pentyl-furan and 2-furfurylthiol. Moreover, pork essence based on enzymatically oxidized fat was richer in 2-methyl-furan and 5-methyl-2-thiophene formaldehyde.

Key words: lipase, lipoxygenase, pork flavor, gas chromatography-mass spectrometry (GC-MS)