The water extract of mustard seed was fractionated by solvents with an increase of polarity, and antimicrobial activities of each extracts were examined, and volatile compounds of each extract were identified by GC-MS. When the water extract was fractionated with solvents, the antimicrobial activities were high in the order of chloroform, ethylacetate, hexane, butanol and aqueous layer. In chloroform fraction, 16 volatile compounds, including 2 isothiocyanates such as 3-isothiocyanato- 1-propene and 4-isothiocyanato- 1-butane, 1 nitrile and 4 acids were identified, their contents were higher than other fractions. Twelve, 10, 4 and 7 volatile compounds were identified in ethylaceate, hexane, butanol and water fractions, respectively. The volatile compounds were considerably less in the fractions of butanol and water than others.

To investigate the food preservative effects of mustard seed(Brassica juncea), mustard seed were added to Kimchi. Titratable acidity of Kimchi treated with mustard seed was higher than that of non-treated control at initial stage, but it was lower than control after 2 days of fermantation. The number of bacteria and lactic acid bacteria increased rapidly at the initial stage of fermentation and reached plateau by 2 days of fermentation. The number of bacteria and lactic acid bacteria of Kimchi treated with mustard seed was lower than that of control, and the more mustard seed added the less bacteria and lactic acid bacteria were observed.