항콜레스테롤 활성이 우수한 유산균주를 이용한 다시마 발효물의 항산화 특성

Abstract

Lactic acid bacteria (LAB) is the key microbes involved in Kimchi fermentation. The object of this study is to develop LAB fermented Saccharina japonica (Kelp) products using Kelp produced in Gijang. The fermentation was performed by starter microbes of Kimchi fermentation. Kelp was fermented by a seasoned red-pepper mixture that has been used for Kimchi fermentation. After the fermentation, LAB was isolated using LAB culture medium. In order to evaluate the biological functions of LAB strains, its acid tolerance, bile tolerance, antioxidant activity and cholesterol-lowering efficacy were assessed. The antioxidant activities of LAB strains were analyzed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2-azinobis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging assay, oxygen radical absorbance capacity (ORAC) assay and ferric reducing antioxidant power (FRAP) assay. Total 15 kinds of LAB were isolated and all LAB showed excellent acid tolerance, bile tolerance and antioxidant activity. The cholesterol lowering activity of LAB strains was measured in range of 15.50 to 94.77%. Three strains of LAB with outstanding cholesterol lowering activity were selected as Kelp fermentation starter and the antioxidant activity of fermented products was analyzed during fermentation period. Among of the selected LAB, Lactobacillus plantarum D-11 showed the highest increasing rate of antioxidant activity during fermentation period. This study suggests that the LAB strain isolated from Kelp-Kimchi can be a potential source for the development of various Kelp-fermentation products in the future.