Sensory and Microbiological properties of Dongchimi added with Jasoja(Perillae semen)

자소자 첨가 동치미의 관능적 및 미생물학적 특성

An optional ingredient, jasoja(Perillae semen), was adopted to improve the quality of Dongchimi. The final weight percentage of jasoja in Dongchimi was adjusted to 0, 0.25, 0.5, 0.75, or 1.0%, per radish, and sensory and microbiological characteristics were determined during fermentation at 10 for 45 days. The effect was varied depending on the amounts of jasoja, but Dongchimi fermented with 0.5% jasoja was most favored for color, flavor, taste, texture, and overall acceptability in sensory evaluation. According to a quantitative descriptive analysis for the product, the liquid portion of Dongchimi steadily became clearer and less sour in proportion to the amount of added jasoja. However, a strong off-taste was detected from 1.0% treatment. The viable cell numbers of total and lactic acid bacteria drastically increased during the first 2 days, and then gradually increased to their maximum values during fermentation and slowly decreased at the later stage. Dongchimi with 0.5% treatment showed a distinctive high number of microorganisms at the 15th-day of fermentation and this trend was maintained until the completion of fermentation. The lactic acid bacteria isolated and identified from Dongchimi were; Lactobacillus brevis, Lactobacillus plantarum, Leuconostoc mesenteroides, Lactococcus faecalis, and Lactococcus lactis. The combined number of Lactobacillus brevis and Lactobacillus plantarum began to increase right after preparation to as much as 10$\^$7/CFU/㎖, then decreased to 10-10$^3$CFU/㎖ afterward. This study showed that the addition of jasoja retarded the initial fermentation of Dongchimi; however, too much jasoja at above 1% weight level per Chinese radish might accelerate fermentation at the later fermentation stage and shoud be avoided. A comparable fermentation pattern was observed among the samples; however, more acceptable Dongchimi could be prepared by fermenting for 11 to 30 days at 0.5% jasoja concentration per radish.