• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.2
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• pp.178-184
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• 1990

The lipid components, nitrogenous extracts and amino acids of dark muscle(DM) of ski-pjack (Katsuwonus pelamis) were analyzed and compared with those of white muscle (WM). WM was higher in moisture and crude protein content, and lower in crude lipid and ash content than those of DM. Contents of volatile basic nitrogen in WM and DM were 22.7mg/100g and 46.9mg/100g. Total lipid(TL) of WM and DM consisted of $79.7\%,\;71.9\%$ neutral lipid(NL), $6.8\%,\;9.5\%$ glycolipid(GL), and $13.5\%,\;18.6\%$ phospholipid(PL), respectively NL was mainly com-posed of free fatty acid, triglyceride, and PL was mainly occupied by phosphatidyl ethanolamine, phosphatidyl choline. Also Iysophosphatidyl choline and Iysophosphatidyl ethanolamine were identified in PL. In fatty acid composition of TL, NL, GL and PL, WM revealed higher contents in saturates and monoenes such as 16 : 0, 18 : 1, while DM showed higher contents in polyenes such as 22 : 6 especially. The major fatty acids of these samples were generally 16: 0, 18:0, 18:1, 20:5 and 22 : 6. Contents of total free amino acids from WM and DM were 5,982.3mg/100g and 4,450.7 mg/100g (dry base). Of free amino acids, Tau concentration was much higher in DM than in WM, Ala, Gly, Met, Arg, Thr were also high in DM. But His was much higher in concentration in W. Content of inosinic acid(IMP) in WM(680.9mg/100g) was higher than that of DM(73.1mg/100g). The degradations of IMP proceeded very rapidly in DM. DM contained much higher trimethylamine oxide and trimethylamine than those of WM. The profile of combined amino acids in these samples, were very similar, and main amino acids were Glu, Asp, Lys, Ala, Ile and Arg.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.123-129
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• 1991

The skipjack and Alaska pollack meat were packed in square No. 3B can, and thermally processed at $121.1^{\cir}C$ so far as to reach Fo values of 5, 10 and 20, respectively. Also the another samples which were heated at $98^{\cir}C$ for 30 minutes were prepared. We have examined the changes of nitrogenous extractives and texture by thermal processing at high temperature in both fish meats. Moisture contents of both fish meats decreased slightly with the increasing of Fo values. When the samples were heated at $98^{\cir}C$ and $121.1^{\cir}C$, pH and VBN contents increased markedly in both fish meats; increasing ratio of pH and VBN contents in skipjack meat was larger than those of Alaska pollack meat. Histamine were detected in concentration of 6.1mg/100g, 0.1mg/100g in raw skipjack and Alaska pollack meat, 8.2mg/100g, 0.1mg/100g in Fo 20 samples of these fish meats, respectively. The contents of total free amino acids in skipjack and Alaska polack meat were 984.8mg/100g, 282.3mg/100g, and these total contents decreased slightly with increasing of Fo values. Little changes were observed in free amino acid composition, but only His, Tau, Ala in skipjack meat and Tau in Alaska pollack meat decreased significantly by heat treatment. Also the degredation of IMP were Proceeded during Preparation and heat treatment of samples, and TMAO changed into TMA almost equivalently. In changes of textures, as compared with heating of 98t for 30 minutes; Fo 5 heat treatment became more softened these fish meats.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.459-464
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• 1991

The mackerel meat was packed in square No 3B can, and thermally processed at $121.1^{\circ}C$ to reach Fo values of 5, 10 and 15. On heating at $121.1^{\circ}C$, pH and volatile basic nitrogen content increased markedly, and histamine was detected at concentrations of 3.98 mg/100g in raw meat, 10.45 mg/100g in Fo 5 sample, 7.54 mg/100g in Fo 15 sample, respectively. Total free amino acid content of mackerel meat decreased with increasing Fo values. Little changes were observed in free amino acid composition, but histidine decreased significantly during heat treatment. Degradation of inosine monophosphate was proceeded during preparation and thermal processing of samples, and trimethylamine oxide changed to trimethylamine almost equivalently. In changes of lipid components, peroxide and carbonyl values were increased markedly during heat treatment. When the sample was heated at the Fo values of 5 or higher, content of non-polar lipid(NL) was increased while that of polar lipid(PL) was decreased, and percentages of polyenes such as 22 : 6 decreased with increasing Fo values. The decomposition of polyunsaturated fatty acids in PL were much greater than those in total lipid and NL.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.327-333
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• 1993

The processing conditions and quality of sardine surimi were examined: Raw sardine meat was separated, washed in 0.2% $NaHCO_3$ and 0.15% NaCl solution, and then dewatered by centrifuge. The dewatered sardine meat was chopped, mixed with 20% emulsion curd (soybean protein : water : refined sardine oil=1:5:2.6), 4% sorbitol, 4% sucrose, 0.2% polyphosphate and 0.1% sodium erythorbate by stone mortar. The mixed sardine meat was frozen with contact freezer, packed in carton box and then stored at $-25{\pm}2^{\circ}C$. The moisture, crude protein and lipid contents of the sardine surimi product was 73.3%, 15.0% and 6.9%, respectively. Fatty acid composition of product consisted of 28.8% of saturates, 24.3% of monoenes and 47.7% of polyenes and the major fatty acids were 16:0, 20:5, 18:1, 22:6 and 16:1. The results of changes in POV, TBA value, fatty acids, texture and sensory score of products during frozen storage showed that lipid oxidation and freeze denaturation of product could be retarded, and flavor enhanced by addition 20% emulsion curd and 0.1% sodium erythorbate. In an attempt to apply sardine surimi in producing surimi-based product, it was concluded that pollack surimi could be substituted with sardine surimi up to 40% without showing any significant changes in texture and taste of surimi-based product.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.233-240
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• 1982

Some environmental parameters on the shell-fish farms in Deukryang and Gamagyang Bays during summer in 1981 were determined to find an eutrophication level for the conservation of the farm. Chlorophyll-a content in the seawater in the Deukryang Bay in September was $1.0{\sim}5.0{\mu}g/l$ with an average of $2.5{\mu}g/l$ In the superficial bottom muds, contents of COD were 5-10 mg/g, ignition loss $5-9\%$, phaeophytin pigment $2{\sim}5{\mu}g/g$, and sulfide 0.1-0.3 mg/g dry mud in both bays. High contents of both organic matters and sulfide were found in the innermost area of the Deukryang Bay and in the north western part of the Gamagyang Bay. All quantities including chlorphyll-a in the water are little less than or similar to those of Hansan-Geoje Bay, one of the most productive shellfish farms in the southern coastal waters in Korea . Eutrophication on both water and bottom mud was under way like other shellfish farms but pollution indices on the bottom mud calculated from the data of CODs and phaeophytin pigments shelved 6-11, which is much lower than those of Jinhae Bay and of the Hansan-Geoje Bay. This means that the bottom muds are in an early stage of eutrophication, unlike the Jinhae and Hansan-Geoje Bays though the water, similar to the other bays, shows a middle stage of eutrophication.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.498-504
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• 1989

Processing conditions and food components of frozen seasoned anchovy meat products were investigated. The separated anchovy meat was chopped, mixed with 12.8% emulsion curd, 0.5% table salt, 2.0% sugar, 0.4% sodium bicarbonate, 0.2% polyphosphate, 0.2% monosodium glutamate, 0.3% onion powder, 0.1% garlic powder, 0.1% ginger powder, 3.0% soybean protein, and 0.2% sodium erythorbate by remodeled stone mortar. This seasoned anchovy meat was frozen with contact freezer, Packed in a carton box and then stored at $-25{\pm}2^{\circ}C$. The major fat acids of product were linoleic, oleic, palmitic, docosahexaenoic, linolenic, palmitoleic, eicosapentaenoic acid. Amino acid composition of product were mainly consisted of Glu, Asp, Leu, Lys and Ala. The taste compounds of product were IMP 160.0 mg/100g ; free amino acids such as Glu, His, Ala, Leu 503.7 mg/100g ; total creatinine 158.3 mg/100g and small amounts of betaine, TMAO.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.260-264
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• 1983

Organic matters as COD, ignition loss, phaeophytin pigment, and sulfide in the superficial bottom mud in the shellfish farms during summer in 1981 were determined to find an eutrophication level for the conservation of the farms. Both the Goseong Bay and the Jaran Bay, which are productive shellfish farms, are located along the southern coast of the Korean Peninsula. The Goseong Bay is 8m deep with a narrow mouth and approximately $17.5km^2$ in area, and the Jaran Bay 10m deep with $27.3km^2$. The bottoms are silty. Major shellfishes cultured are the oyster by the off-bottom method and the arkshell in the bottom. COD contents were $12.5{\sim}19.5\;mg/g$ dry mud, ignition loss $6.70{\sim}11.83\%$, phaeophytin pigment $6.8{\sim}11.0{\mu}g/g$ dry mud, and sulfide $0.18{\sim}0.64{\mu}g/g$ dry mud. There were no significant differences in the determined quantities between two bays. All quantities except the sulfide which is a little over than an eutrophication level, 0.3 mg/g dry mud, shows that the bottom muds are in an early stage of eutrophication. In addition, there was no particular increase in quantities of aforementioned four paramenters in comparision with those of 1976. It means that the eutrophication in the Goseong-Jaran Bay makes slow progress.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.393-397
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• 1994

The study was carried out to develop the powdered smoked-dried anchovy products as a natural flavoring substance. The processing conditions, chemical and taste compounds of products were as follows: The raw anchovy were washed, and then boiled 5 minutes in $5{\sim}6%$ NaCl and 1.0% sodium erythorbate solution. Boiled anchovy were smoked in smoking house at $40^{\circ}C$ for 4 hours as the first stage, and then increased temperature up to $80^{\circ}C$ as the second stage, and finally smoked 8 hrs at $80^{\circ}C$ to maintain the moisture content between 9 and 10 percent. The smoked-dried anchovy were pulverized and screened to be 50 mesh of particle size, and finally packed in PET/Al/CPP film bag. The moisture, crude lipid content and salinity of powdered smoke-dried anchovy were 9.4%, 9.6% and 6.9%, respectively. Fatty acid composition of product was mainly consisted of polyenes (43.4%) such as 22 : 6 and 20 : 5, followed by saturates (36.9%), monoenes (19.7%). The principal taste compounds of product were IMP, 466.5 mg/100g; free amino acids such as His, Tau, Pro, Lys, Ala and Glu, 1179.2 mg/100g; non-volatile organic acids such as lactic acid and succinic acid, 617.9 mg/100g; total creatinine, 595.9 mg/100g; small amount of betaine and TMAO. To make a instant soup, it was desirable for taste of products that powdered smoked-dried anchovy were mixed with 20% salt, 4.0% sugar, 3.0% MSG, 1.0% onion powder, 1.0% garlic powder and 1.0% black pepper.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.192-196
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• 1989

This experiment was carried out to compare the difference of lipid components, amino acid composition by size of sea eel. Large sea eel(length 57.5-60.0cm, weight 269.5-300.0g) was higher in moisture and crude protein content, and lower in crude lipid content than those of small sea eel(28.8-31.2cm, 39.5-43.6g). Total lipid(TL) of large and small sea eel were consisted of 89.7%, 93.3% neutral lipid, 8.9%, 5.2% phospholipid, and 1.4%, 1.5% glycolipid, respectively. In fatty acid composition of TL, large fishes revealed higher content in polyunsaturated fatty acids such as 20:5, 22:5, 22:6, while lower in saturates and monoenes such as 16:0, 16:1, 18:1 than those of small fishes. The major fatty acids of these fishes were generally 18:1, 16:0, 22:6, 16:1 and 20:5 in order. Total amino acid contents of large and small sea eel were 17022.7mg/100g, 15409.4mg/100g. And the main amino acids were aspartic acid, glutamic acid, isoleucine, leucine, lysine, arginine. Large fishes was higher in cystine, methionine, tyrosine, phenylalanine content, while lower in aspartic acid, glutamic acid than those of small ones.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.4
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• pp.172-179
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• 1988

A cartridge type hydraulic logic valve consists of simple two port valve whose poppet is closed or opened by means of pressure signal of a pilot line. Accordingly, the logic valve can be used not only for direction, flow and pressure control purpose but also for versatile function valve which enables all above mentioned functions. In addition, the valve has little internal leakage and pressure loss, superior response characteristics and easiness in making small block type valve. The above mentioned good performances being recognized recently, the logic valve has been used widely in the large scale hydraulic system such as a hydraulic press system, for the performance requirements of high speed operation and precise control characteristics. However, there are scarce reports until now, except for a few ones from Aachen Institute of Technology in West Germany, so it is necessary to be studied on development and investigation for practical application. This paper showed that the static and dynamic characteristics of a logic valve when the logic valve is used for directional control, to investigate the relations between the valve operating characteristics and the valve design conditions. From the above mentioned procedure, it was ascertained that the valve operation characteristics obtained by numerical analysis showed good agreements with experimental results. The representative results obtained are as follows; 1. During the valve is closing, the poppet velocity is almost constant in the logic valve. 2. The pilot pressure P sub(3) and the resistance R in the pilot line have much influences on the valve operation time. 3. Spring strength have not such a severe influence on the valve operating time. 4. The operation characteristics of the logic valve can be estimated with good accuracy comparatively by numerical analysis with the equations describing poppet motion.