This study investigated the luring effect of the sardine bait, which is used to catch octopus with pot, as the preliminary study for the development of alternative bait for octopus pot. The soaking time for bait was divided into “5 days or less” and “11 days or longer” The number of times octopus entered the pot with bait and the empty pot was investigated under dark adaptation and light adaptation processes and the distribution of tank section was investigated under light adaptation process. The case of “11 days or longer” sardine soaking time showed higher rate of distribution in the section of pot with bait compared to the case of “5 days or less” In the case of “5 days or less” soaking time, the number of times the octopus entered the pot with bait was similar to that it entered the pot without it even during dark adaptation and light adaptation. However, in the case of “11 days or longer”, the octopus entered the pot with bait more quickly than the pot without bait and more frequently during dark adaptation hours. There were cases where the octopus did not enter any pot. In the case of “5 days or less”, with less decomposition of baits, the octopus entered the empty pot more during light adaptation process, and it appeared that the pot was used as a hideout.

This study was attempt to improve the quality of rapid- and low salt-fermented liquefaction of sardine (Sardinops melanoslicta). Effect of pretreatment methods such as water adding, heating, and intermittent NaCl adding on fermented liquefaction of chopped whole sardine were investigated. The divisions of the experimental samples by pretreatment methods were as follows; Sample A (water adding and heating): chopped whole sardine adding 20% water and then adding 3 and 5% NaCl consecutively at the intervals of 3 and 6 hrs during heating for 9 hrs at 50℃ and then fermented at 33℃ for 90 days. Sample B (preheating): chopped whole sardine with 8% NaCl and heating at 50℃ for 9 hrs and then fermented at 33℃ for 90 days. Sample C (control): neither pretreatment methods of water adding nor preheating on chopped whole sardine with 13% NaCl and then fermented at 33℃ for 90 days. Comparison of the appropriate fermentation period, yield of hydrolysate, chemical composition of fermented liquefied products were carried out. The highest content of amino nitrogen appeared at 60 days in the sample A, 75 days in the sample B, and 90 days in the sample C during the fermentation period. The appropriate fermentation period of the sample A was shorten 15 days than the sample B and 30 days than the sample C in the processing of sardine. The product A was lower NaCl (8.5%) and lower histamine content (25mg/100g) than the sample B and C. Possibly, three kinds of pretreatment methods such as water adding, heating, and intermittent NaCl adding, might be recommend as the processing of rapid- and low salt-fermented liquefaction product of chopped whole sardine.

As a part of investigation to use sardine(Sardinops melanoslicta) more effectively as a food source, this study was undertaken the processing condition of rapid- and low salt-fermented liquefaction of sardine. To prepare rapid fermented products, the chopped whole sardine was added 8% NaCl and then preheating treatment at 40℃, 45℃ and 50℃ in the manufactured fermenter(180L) for 9 hrs, and then fermentation at 33℃ for 90 days. The chemical changes such as amino nitrogen(amino-N), volatile basic nitrogen(VBN), and histamine in the hydrolysates of fermented sardine were analyzed as well as viable cell count and organoleptic evaluation during fermentation to compare the quality between control and preheating samples. During fermenting, the amino-N in the hydrolysates increased rapidly during the first 30 days and slowly thereafter. The highest content of amino-N appeared at 75 days in control sample and 60~75 days in preheating samples. The changes of VBN in the hydrolysates increased rapidly during first 15 days in control samples and 30 days in preheating samples. However they were generally low level in preheating samples. Histamine content in the hydrolysates of the control samples increased markedly after 15 days, but preheating samples were generally low level, and then 75~90 days of fermentation reached to the maximum which was about 2.0~3.0 times lower than that of control samples. As for the organoleptic flavor evaluation, the control and preheating at 40℃ samples were unpleasant odor after 15 and 60 days, respectively. But preheating at 45˚ and 50˚ samples were fresh odor after 90 days fermentation.

In order to establish the processing condition of salt-fermented liquefaction of sardine (Sardinops melanoslicta), effect of temperature, pH value, and concentration of salinity on crude enzyme activity of sardine viscera were investigated. The optimum temperature range of crude enzyme activity in sardine viscera was 45~50℃ and the optimum pH value of it was 9.8. According to the concentration of salinity increased the crude enzyme activity in sardine viscera decreased. The relationship between concentration of salinity (X) and the crude enzyme activity (Y) in sardine viscera is shown as follows; Y=-0.01363X+0.7676 (r=-0.88). For the purpose of processing conditions of rapid- and low salt-fermented liquefaction of sardine, changes of viable cell count, histamine content, and volatile basic nitrogen (VBN) in the chopped whole sardine with 8% NaCl during preheating process at 40˚, 45˚ and 50℃ for 48 hrs were analyzed. During preheating, initial viable cell counts of chopped whole sardine were 104-7/g, but they decreased 101-5/g after 48 hrs. Histamine contents during preheating process at 40˚ and 45℃ were gradually increased, whereas at 50℃ were almost the same level after 48 hrs. VBN contents were continuously increased during preheating, but preheating at 50℃ samples were lower level than that of 40˚ and 45℃ ones. For the purpose to accelerate the fermentation and liquefaction of chopped whole sardine, preheating at optimum temperature of crude enzyme activity for 48 hrs was useful processing method and the contents of viable cell count, histamine, and VBN were safety level for food sanitation.

정치망 내외에 있어서 정어리 대형군의 행동조사는 1992년 1월 29일부터 2월 22일 사이에 일본국 석천현 칠미시 연안 정치망어장에서 소나를 이용하여 실시하였고, 소나의 영상기록을 해석하여 얻어진 결과를 요약하면 다음과 같다. 1. 정치망 바깥쪽 부근에서 이동중인 어군의 행동양식은 어군의 각 위치에 따라 다른 행동이 관찰되었고, 부분적인 확대와 축소를 보이면서 어군전체가 이동하였다. 2. 헛통입구로 들어간 어군은 등망방향, 헛통의 등방향, 헛통의 옆줄방향으로 분산되었으며, 그후 헛통의 등방향, 헛통의 옆줄방향, 입구방향의 어군은 등망쪽으로 조밀하게 이동하는 행동양식을 취하면서 입구로부터 외등망까지 이동하였다. 3. 정치망의 안쪽과 바깥쪽에 있어서 어군의 주연부가 확대하는 경우, 최대 이동속도는 바깥쪽에서 277cm/sec, 안쪽에서 176cm/sec이었다.

대형정치망내에 있어서 어군의 행동 조사는 1992년 1월 29일부터 2월 22일 사이에 일본국 석천현 연안 정치망 어장에서 실시하고, 정치망어구의 어획기능에 관해서 해석, 검토하였으며, 얻어진 결과를 요약하면 다음과 같다. 1. 헛통에 출현한 어군수는 17~18시의 일몰시에 가장 많았고, 그후 급격히 감소하는 경향이었다, 이것으로 보아, 헛통에 있어서 어군의 체류시간은 짧고, 비교적 빠르게 원통에 입망했던가 혹은 헛통의 입구로부터 도피했다고 생각된다. 2. 망내에 입망한 정어리소형군의 행동은 측망에 평행한 직선적인 주복이동이 많고, 등망의 부근에서는 방향을 전환하여 헛통의 옆줄에 향하는 행동이 관찰되었다. 3. 망내에 입망한 정어리소형군의 이동속도는 25cm/sec가 최빈치이고, 최대 이동속도는 80cm/sec 이었다.

In order to fractionate sardine oil by different solvents for an effective use of fish oil being subjected to the limit of use, an attempt was to investigate the proper solvents, ratios and fractionation time. The results of the study were as follows: 1. The proper solvent of fractionation using ethanol, isopropyl alcohol, acetone, and hexane was ethanol, and its optimum ratio was 2:1 (ethanol: oil, v/w). The proper time of ethanol fractionation by the ratio (2:1) was 4hr at 10℃, 6hr at 5℃, 8hr at 0℃and 8hr at -5℃, respectively. 2. In the fractionation by stages using the ratio (2:1) at each temperature, the yield of stearine was 8％ at 10℃ (Fraction I), 32％ at 5℃ (Fraction II), 7％ at 0℃ (Fraction III) and 10％ at 0℃ (Fraction IV), respectively. When ethanol fractionation was undertaken at 5℃ by stages, the yield of stearine (Fraction II) was high. 3. Iodine value of Fraction II was 96.8. This result indicated that the hydrogenation process would be simplified by fractionation. 4. The percentage of the decrease of polyenoic acids from original sardine oil to Fraction II oil was from 30.5％ to 13.5％. The major fatty acids of Fraction II were palmitic and oleic acids and these fatty acids were about 52％ of total fatty acids. Therefore, Fraction II, which remained liquid oil at room temperature because solid fat content was 6.9％ at 20℃, would be used as frying oil.