김치 종균 Leuconostoc kimchii GJ2의 특성 규명 및 종균김치의 제조

Abstract

Leuc. kimchi GJ2 isolated from kimchi showed antibacterial activity against various species of gram-positive and gram-negative bacteria. Bacteriocin production was increased from 1600 unit to 3200 unit when Leuc. kimchii GJ2 was cultivated with intracellular extract of antibacterial-sensitive strain, Lactobacillus sakei NJ1. The antibacterial activity was stable at 100℃ for 30 min, but it was unstable over pH 5.0. Leuc. kimchii GJ2 did not produce biogenic amine in decarboxylase agar medium. Thin Layer Chromatogram of the mannitol produced by Leuconostoc kimchii GJ2, Leuconostoc kimchii GJ3, Lactobacillus sakei YY1, Lactobacillus sakei WJ1, Lactobacillus sakei SC1. Leuc. kimchii GJ2 has effect on mannitol production. but, other strains did not produce mannitol. Kimchi was prepared using an induced antibacterial-producing bacterium, Leuc. kimchi GJ2 as a starter. The kimchi was fermented at 6.5℃ for 9 days, and then stored at -1℃ for 112 days. The acidity of the stater kimchi was increased slowly and reached 0.89% by 112 days of storage, whereas non-starter kimchi was 1.01% of the acidity at 112 days of storage. At that time, the dominance rate of Leuc. kimchi GJ2 was 80.62% in the starter kimchi. Amount of produced EPS from the starter kimchi, which was fermented at 6.5 ℃ for 7 days, was 5.07 g/L. Whereas, production of EPS from the non-starter kimchi, whichi was fermented at 6.5 ℃ for 12 days, was 3.72 g/L. The amounts of produced EPS were maintained during the storage of kimchis at -1℃ for 30 days. Tastes of GJ2-starter kimchi was characterized by soft sweetness, refreshed and crisp freshness. Control without starter tasted very sour and smelled bad. Moreover, the control kimchi showed soften of texture upon long-term storage. It was surely recognized that in Kimchi using Leu. kimchii GJ2 as starter, controlled microbial growth or fermentations occurred.