Abstract:In order to study the differences in the volatile flavor compounds of long-terms fermented kohlrabies for different time periods, Sichuan long-term fermented kohlrabies for 6 years (6Y), 8 years (8Y) and 10 years (10Y) were employed in the present study. The volatile flavor compounds of the three long-term fermented kohlrabi were analyzed by gas chromatography-mass spectrometry (GC-MS), combined with multivariate statistical analysis. The results showed that 58 volatile flavor compounds were detected in the three long-term fermented kohlrabies, including 35 acids, 12 alcohols, 5 esters, 4 aldehydes and 2 ketones. During fermentation, the content of esters first declined then increased, the content of acids first increased then declined, and the alcohol content showed a decreasing trend. Acidic compounds were the most abundant volatile flavor compounds in long-term fermented kohlrabi, accounting for 73.05%, 78.07% and 60.42% of the 6Y, 8Y and 10Y fermented kohlrabi, respectively. The content of esters increased from 2.36% to 17.72%. Multivariate statistical analysis showed that there were significant differences in the volatile flavor components of the three long-term fermented kohlrabi. Data analysis showed that various flavor substances underwent different degrees of chemical reactions during the fermentation process, causing the formation of unique flavors of long-term fermented kohlrabi for different years. The present study revealed the changing trend of flavor substances during long-term fermentation of kohlrabi, and provides a theoretical basis for the development of long-term fermented kohlrabi products.
