Jeotgal is a salty and fermented traditional Korean fish sauce. Unlike most other previous studies that investigated samples purchased from retail markets, this study focused on samples of jeotgal with traceable history to Yeonggwang, a timehonored fishing village in Korea. Three jeotgal samples, which were made from small yellow croakers, largehead hairtail, and miscellaneous fish, were selected based on information obtained from interviews with local craftsmen and literature reviews. Bacterial community profiles of the three jeotgal samples were investigated to identify indicator (and potentially core) bacteria for jeotgal ripening. The 16S rRNA gene-based metagenomic analysis revealed that the dominant phyla and classes, (Gammaproteobacteria, Betaproteobacteria, Bacilli, and Clostridia) of the three different jeotgal were identical, albeit with different composition ratios. Diversification was evident beginning at the order level. Interestingly, each dominant order was mainly comprised of single members even at the genus level. The dominant genera included Halomonas, Tetragenococcus, Halanaerobium, Pseudomonas, Massilia, and Lentibacillus. This observed genus-level heterogeneity suggests that there are diverse bacterial signatures in jeotgal and that these can be used as indicators for jeotgal ripening and/or as starters to increase its sensory quality and functionality.

A γ-aminobutyric acid (GABA) producing microorganism was isolated from Sun-Tae Jeotgal, a Korean traditional fermented seafood. Two thousand presumptive lactic acid bacteria (LAB) isolates were screened for GABA production by thin layer chromatography. One isolate, T118, produced GABA profusely, and identified as Lactobacillus brevis. Growth of Lb. brevis T118 was examined during 120 h cultivation in MRS broth under different conditions. Lb. brevis T118 grew well at 30-37℃, initial pH of 4-7, and up to 5% NaCl (w/v). A gene, gadB, encoding glutamate decarboxylase (GAD) was cloned by PCR. gadC encoding a glutamate/GABA antiporter was cloned and gadC located immediately upstream of gadB, indicating gadCB operon structure. The operon structure was confirmed by reverse transcription (RT)-PCR. gadB was overexpressed in Escherichia coli BL21 (DE3) and recombinant GAD was purified. The size of recombinant GAD was 54.4 kDa by SDS-PAGE, which matched well with the calculated size from the nucleotide sequence.

This study investigated the prevalence of total aerobic bacteria, coliform and food poisoning (Bacillus cereus) bacteria in commercial Jeotgal for the evaluation of microbiological safety. The mean mass of total aerobic bacteria was 4.8±1.4 log CFU/g in Jeotgal. Coliform was detected in 17 (48.6%) of 35 seasoned Jeotgal; 14 (42.4%) of 33 low salted Jeotgal compared with three (16.7%) of 18 general salted Jeotgal; and in three (37.5%) of eight HACCP certificated Jeotgal compared with 14 (32.6%) of 43 non-HACCP certificated Jeotgal. Bacillus cereus was detected in two (12.5%) of 16 non-seasoned Jeotgal compared with 20 (57.1%) of 35 seasoned Jeotgal; in 19 (57.6%) of 33 low salted Jeotgal compared with three (16.7%) of 18 general salted Jeotgal, and in four (50.0%) of eight HACCP certificated Jeotgal compared with 18 (41.9%) of 43 non-HACCP certificated Jeotgal. Overall, our results showed that coliform and B. cereus contamination was highest in the seasoned and low salted Jeotgal. It is necessary to improve the microbiological safety low salted and seasoned Jeotgal. The HACCP system in Jeotgal is reconfirmed for the enhancement of microbiological safety.

본 연구는 전복내장을 이용하여 젓갈을 제조과정 중 이 화학적 변화와 제조된 젓갈의 품질특성에 대하여 조사하였다. 전복내장의 영양학적 성분을 분석한 결과 탄수화물, 단백질 및 미네랄이 풍부하여 젓갈발효에 우수한 성분특성을 갖고 있었다. 젓갈 발효중 pH는 경시적으로 감소하는 경향을 보였으며 염도가 pH 변화에 영향을 미치지 않았다. 휘발성염기질소함량은 발효중 염농도에 따라 현저한 영향을 받았으며 고염발효의 경우 저염발효에 비하여 휘발성염기질소 함량이 현저하게 낮음을 알 수 있었다. 아미노태질소 함량은 발효중 꾸준히 증가하는 경향을 보였으며, 염농도가 낮을수록 높은 값을 보였으나 염농도에 따른 변화는 크지 않음을 알 수 있었다. 발효과정중 protease 활성 변화를 측정한 결과 고염에서 활성이 떨어지는 경향을 보였으며 발효 30 일경 최고 활성을 보였다. 전복내장과 발효 전복내장젓갈의 유리아미노산 함량을 분석한 결과 젓갈 중 7종의 아미노산이 내장에 비하여 낮게 나타났으며 26 종의 아미노산이 높게 나타났다. 전복내장 젓갈의 총유리아미노산 함량은 62.75 mg/g 으로 전복내장 30.37 mg/g에 비하여 약 2배 증가하였다. 관능평가 결과 색과 종합기호도에서 우수하였으며 상품화를 위해서는 맛과 향의 개선이 필요한 것으로 판단되었다. 전복내장젓갈에 대한 최초의 연구논문으로 향 후 타 연구에 기초자료를 제공할 수 있을 것으로 생각된다.

명란젓갈을 0.5, 1, 2 및 5 kGy로 전자선 조사 후 2주간 냉장 저장하면서 전자선 조사가 명란젓갈의 미생물학적 변화와 품질에 미치는 영향을 조사하였다. 저장 중 전자선 조사(약 2 kGy)에 의해 명란젓갈에 존재하는 총 호기성 세균, 효모와 곰팡이 그리고 대장균군의 수가 유의적으로 검출한계() 이하까지 감소함이 확인되었고, 전자선 조사에 의한 미생물의 사멸에 따라 전자선 조사구에서 pH가 유의적으로 높게 유지되었다. 관능적 품질에서 저