면역분석기법을 이용한 서부경남 시판 메주 및 된장에서의 Aflatoxin 생성균 검색

다국어 초록 (Multilingual Abstract)

Generally, non-aflatoxigenic fungi, such as Aspergillus oryzae, and Aspergillus niger are main microflora in Korean traditional fermented foods including Meju and soybean paste, but sometimes, Aspergillus flavus and Aspergillus parasiticus can be contaminated and accumulated aflatoxins during fermentation and storage. So the screening of aflatoxigenic strains in fermented traditional food is very important to improve the sanitary quality of those foods. In this work, we screened aflatoxin producing fungi from commercial Meju and soybean paste in Western Gyeongnam by immunoassay. Samples were randomly purchased from market of the commercial Meju(10 EA) and soybean paste(20 EA) in nine areas of Western Gyeongnam. Of the samples collected, 24 strains and 22 strains of Aspergillus sp. were isolated from Meju and soybean paste, respectively. The isolated strains were cultured on SLS media at 25℃ for 15 days. The cultured broth were extracted with ethyl acetate and were analysed to determine aflatoxin B₁(AFB₁) by direct competitive ELISA(DC-ELISA). Six strains(25%) isolated from Meju, and 2 strains(9%) isolated from saybean paste, were confirmed as aflatoxin producing strains. The average range of aflatoxin productivity of isolates from Meju was 54.6 ± 38.7 ng/ml and that from soybean paste was 11.1 ± 8.6 ng/ml, respectively. Among them, isolated strain No. M-5-4 produced a high level of AFB₁ and showed 98.26 ng/ml of AFB₁. Every isolates were also re-confirmed their AFB₁ productivity by thin layer chromatography(TLC). The TLC results also showed same trend as DC-ELISA results. As the above results, the screening of hazard mycotoxigenic fungi from traditional fermented foods should be necessary for the safety and the application of HACCP system in the food manufactory in Korea.