Analysis of quality and volatile components in pickles during natural fermentation

Several quality indexes of pickles including total number of lactic acid bacteria, physicochemical properties and sensory evaluation were detected in order to learn the discipline of quality variation during fermentation. Methods of headspace solid phase micro- extraction ( HS- SPME) and gas chromatograph- mass spectrometry ( GC- MS) were used to detect the volatile components.The results showed that the quality of pickles was the best in the sixth day of fermentation. Type and relative content of volatile components were distinct at different fermentation time.A total of 45 types of volatile components were identified.Relative content of esters was the highest during fermentation which made it a characteristic component in pickles of cabbage. The volatile components were analyzed by method of principal component analysis ( PCA) . It showed that thiocyanic acid methyl ester, ( E) - Hex-4- en- 1- yl butyrate, acetic acid hexyl ester, ( Z) - 3- Hexen- 1- ol, 1- Hexanol, .beta.-Pinene, disulfide dimethyl, dimethyl trisulfide were the main components contributed to the flavor of pickles.