Abstract
The optional ingredient jasoja(Perillae semen) was adopted to improve Dongchimi in qualify during fermentation The final weight percentage of jasoja in Dongchimi was adjusted to 0, 0.25, 0.5, 0.75, or 1.0% Per radish. Physicochemical characteristics were determined during fermentation for 45 days at 10$^{\circ}C$. As the fermentation of Dongchimi proceeded, the pH decreased with the increase of total acidity; however, the decreasing rate was slowed down by increasing the level of jasoja. The delayed pH drop of Dongchimi was limited only for the initial period of fermentation and the ultimate pH became almost comparable even for the 1% treatment. The total vitamin C content increased initially to a certain level depending on the level of jasoja, and then decreased later. Dongchimi with 0.5% jasoja contained the highest level of total vitamin C and reducing sugars. In case of 1% treatment, the typical pattern of an initial high content followed by a gradual decrease in reducing sugar was destroyed by a rapid fermentation at the later stage. Turbidity level, along with total solid contents of the liquid part of Dongchimi increased in all treatments as the fermentation proceeded although the extent was rather suppressed by jasoja. As a result of fermentation, the colorimetric lightness values decreased, with the intial increase followed by the decrease at a certain point in redness and yellowness and the increase in color difference values (ΔE). Overall, fermentation with 0.5% jasoja for 11 to 30 days appeared to improve the quality of Dongchimi.