김치 종균 배양용 식용 배지 개발 및 이를 이용한 김치 숙성도 제어 방법

Abstract

To control the fermentation rate of kimchi, we studied the composition of an edible medium for co-culturing of mixed starter including Lactococcus lactis WiKim0098 and Leuconostoc citreum WiKim0096. The effect of kimchi broth ingredients such as dried pollack, seaweed, onion, radish, dried red pepper, green onion, dried mushroom, and dried shrimp on the growth of L. lactis WiKim0098 and Leu. citreum WiKim0096 were evaluated. All ingredients except for dried shrimp inhibited the growth of bacteria. By comparing the bacterial growth and antibacterial activity of M17 medium in which L. lactis grows well, the final edible medium composition was determined as yeast 3% extract, 0.05% ascorbic acid, 1% potassium citrate, and 3% lactose in 1% dried shrimp broth (namely, edible medium 1). Subsequently, to mix-culture Leu. citreum with excellent mannitol-producing ability, various carbon sources were added to edible medium 1, and the growth of Leu. citreum was then measured. Leu. citreum grew well at a concentration of 0.1 to 1% of maltose or fructose in a dose-dependent manner. Based on these results, different concentrations of maltose (0.1, 0.2, or 0.3%) were added to the edible medium to control the growth rate of Leu. citreum. Each of these was added to kimchi and fermented at 10°C for 5 days, and the pH was measured. The kimchi added only L. lactis showed a pH of 5.3, while each treatment group showed a tendency to decrease the pH as the maltose concentration increased to pH 4.9, pH 4.7, and pH 4.5. Consequently, the use of the edible liquid medium developed in this study was able to control the ratio of L. lactis WiKim0098 and Leu. citreum WiKim0096 in co-culturing of kimchi starter. Moreover, the fermentation rate of kimchi was controlled by mixing L. lactis and Leu. citreum, resulting in could control the kimchi ripening.