Abstract
Identification and change of microflora during the fermentation of anchovy Engraulis japonica, under the halophilic circumstance were investigated. The change of salinity and pH in meat and juice which decide the environment for microorganism and decomposition of nitrogenous compound which functions as a nutrient source were also discussed by measuring the content of total-N, amino-N, nonprotein-N, TMA and VBN, The fresh anchovy was mixed with rock salt (20 percent w/w) and stocked for six months. Through the fermentation lag phase of viable cells extended for 20 days that was obviously larger compared with other circumstances, hereafter increased to reach the maximum value of $5\times10^4$ total count per gram at 35 day stock. The stationary phase proceeded for 25 days. 540 strains were isolated and among them 11 genus of bacteria, 3 genus of yeasts, were identified and other 2 yeast strains of unidentified. At the initial stage of fermentation, Pseudomonas, and Helobacterium prevalently grew, at the middle stage, they disappeared rapidly and Pediococcus and yeasts completely dominated, where they are assumed to get directly involved with fermentation of fish, The PH value tended to decrease in the progress of fermentation and at 100 day stock it showed the minimum value of 5.5 to 5.6 in both meat and juice. The highest salinity of meat decreased to 18 percent, while in juice it decreased to 28 percent since 50 days stock. The content of total-N in meat gradually decreased to 2.8 percent, while in juice it increased to 2.3 percent at 100 day stock, However nonprotein-N was 1.8 percent and amino-N was 1.1 Percent. Since 100 days stock, the increasing rate of amino-M is too low it could be judged to entered the final stage of fermentation, In the first 20 days stock, the increase of VBN and TMA can be explained by the growth of putrefactive bacteria such as pseudomonas on the meat before salts penetrate into the fish meat, while reincrement after 100 days stock, is explained by decomposition of free amino acid due to the reactions of bacteria and enzymes.
멸치 젓갈의 숙성에 따른 미생물의 종류와 그 상(相)의 변화를 구명하기 위하여 생육 환경을 지배하는 염분농도와 pH의 변화 그리고 영양원인 질소화합물의 분해과정을 total-N, amino-N, protein-N, non-protein-N, TMA, VBN의 측정으로 고찰하였다. 산업적으로 젓갈 제조시기인 1973년 5월 부산 근해산 봄멸치를 인도산 암염율 $22\%$ (w/w) 가하여 $20\~25^{\circ}C$에서 숙성시키면서 약 6개월간 실험한 결과를 요약하면 다음과 같다. 1. viable cell 총균수로 본 lag phase는 약 20일간이었고 이후 급격히 증가하여 35일 경에 최고치 $5\times10^4$/g에 달하였으며 Stationary phase가 약 20일간 유지되었으며 lag phase가 긴 것이 특징이었다. 2. 숙성초기에는 ($0\~30$일) Pseudomonas, Achromobacter, Flavebacterium, Brevibacterium Pedioceccus Sarcina, Micrococcus와 중기에는 Saccharomyces, Torula가 분리되었으며 그 중에서 Pediococcus 가 가장 우세하였다. 3. pH값은 숙성이 진행될수록 하강하다가 100일 경에 $5.5\~5.6$에서 거의 일정하였다. 4. 염분 농도는 육질에서 10일경에 최고치 $21\%$에도 달하였다가 서서히 감소하여 $18\%$에 이르고 것에서는 감소하여 50일 경에 $28\%$를 유지하였다. 5. 질소 화합물의 변화는 육질에서는 total-N이 제조후 10일에 $3.3\%$ 최고치에 달하였다가 감소하여 100인 후에는 $2.8\%$로 거의 평형을 유지하였고 젓국에서는 증가하여 100일 경에 total-N $2.3\%$, non protein-N$1.8\%$, amino-N$1.1\%$에 달하여 완만하게 증가하고 젓죽 및 육질중의 TMA는 악 10일 후에 $9mg\%$에 달하여 평행을 이루다가 100일 이후에는 약간증가했고 VBN은 20일 후에 $80\%$에 달한 후 100일까지는 완만하게 변하다가 120일 후에는 다시 증가하여 젓국에서는 $160mg\%$, 육질에서 $140mg\%$ 었다.