Effects of jogi, Micropogonias undulatus, addition on the production of volatile compounds in baechu-kimchi

Baechu-kimchi is a traditional vegetable fermented food using kimchi cabbage (Brassica rapa) as the main ingredient. A wide variety of ingredients can be used in kimchi depending on the specific region and even household. Although there have been a lot of studies examining various aspects of kimchi, there has been limited research on kimchi with added fish as a minor ingredient. Therefore, in the present work we aimed to assess changes in the volatile compounds of baechu-kimchi with the addition of seafood used as minor ingredients of kimchi. Sulfur compounds were the most commonly detected volatile compounds; 9 categories of volatile components were detected in total. Altogether, 30 sulfur compounds were detected, and among them, five sulfur compounds: (E)-1-(methyltrisulfanyl)prop-1-ene, 1-(methyldisulfanyl)-1-methylsulfanylpropane, (methyltetrasulfanyl)methane, 1-(methyldisulfanyl)-1-[(E)-prop-1-enyl]sulfanylpropane, and 1,1-bis(methyldisulfanyl)propane, were found only in jogi-added kimchi, thus confirming the influence of jogi addition. Principal component analysis revealed clear distinctions in the volatile compounds as a result of jogi addition as fermentation progressed. Moreover, when confirming the correlation with microbial populations, it was evident that the differentiation in volatile compounds was more attributable to jogi addition than microbial impact. In conclusion, the addition of jogi to baechu-kimchi led to an abundance of volatile compounds by the 20th day of fermentation.