• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.4
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• pp.177-183
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• 1987

The catch by the set net fishery from 1971 to 1985 were analyzed in order to reveal its fluctuation characteristics. Generally, the catch increased from 16,787M/T in 1971 to 84,103M/T in 1985 and showed maximum in 1979 with 99,475M/T of catch. This trend was mainly related to the higher production of file fish which accounts for 64% of the total catch in 1979, and the change of catch statistical classification according to the revising of fishery law in 1976. It was also closely related to the variation of the sea water temperature in coastal area. The main fishing period of the set net fishery appeared from October to November. Catch of the set net fishery was led by that in the southern coast before 1976 and by that in the eastern coast from 1977 to 1980, the tendency changed irregular from 1981. Three groups of fishes could be distinguished by principal component analysis of the annual catch. A group showing steady decreasing tendency was composed of the fishes such as whiting, sand fish, hair tail and anchovy. The another group composed of small alaska pollack, round herring, goby, gizzard shad, sand lance and file fish revaled an increasing tendency. The other fishes did not show any annual tendency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.823-828
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• 1998

The objective of this study is to investigate cryoprotective effects of corn starch enzyme hydrolysates of nonsweet and low-calories on denaturation of frozen fish protein. The cryoprotective effects of were examined in Alaska pollack actomyosin solution by changes in SDS-PAGE pattern, solubility, and $Ca^{2+}$-ATPase activity. When samples stored for 0 and 30 days were compared on SDS-PAGE patterns, severe changes in all bands were shown on the control sample regardless of storage temperature, especially in myosin heavy chain (MHC). Not much difference no appeared the electrophoretic pattern in case of the samples containing sucrose at any storage temperature during 30 days of storage. The cryoprotective effect of the hydrolysates were markedly dependant on storage temperature and no MHC band was found in the samples stored at $-5^{\circ}C$. The SDS-PAGE patterns of sample stored at $-20^{\circ}C$, however, completely maintained after 30 days or storage. When the samples were stored at $-5^{\circ}C$, the solubility of the sample containing sucrose was retained at $90\%$ after 30 days of storage, whereas dramatically decreased in other samples. The samples including sucrose, D.E. 10, 15, and 20 revealed $90\%$ in solubility when stored at $-20^{\circ}C$. The tendency of remaining $Ca^{2+}$-ATPase activity was almost shown the same as that of solubility.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.3
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• pp.200-213
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• 1993

A model experiment on a midwater rope trawl net which is used in the North Pacific to catch alaska pollack is carried out in the circulating tank to examine the basic efficiency of the net. The prototype is the net used by M/S Hanil(1, 179GT, 2, 700PS), a Korean trawler. The model net was made according to the Tauti's Similarity Law of Fishing Gear in 1/100 scale by considering the condition of the tank. To measure the basic efficiency of the standard model net, the vertical opening and width between some points marked on the net were measured, and the hydrodynamic resistance were determined. Then the constructive conditions of the net were varied as follows and the factors were measured again to compare the efficiency of those nets with that of the standard net(A-1 type) front weight multiplied 1.5 times: A-2 type. buoyancy and depressing force multiplied 1.7 times: A-3 type. front weight multiplied 1.5 times on A-3 type: A-4 type. depressors rigged at ground rope: B type. cod-end stuffed with cashmylon wad: C type. The results obtained can be summarized as follows: 1. The vertical opening at the center of head rope was steeply decreased with the flow velocity increasing and the vertical opening H(m) can be expressed in H=1.2v super(-1.2)(v : flow velocity in m/sec). The width of the net varied a little when the flow velocity was over 0.4m/sec, and the width of net mouth showed about 37% of the distance between the fore tips of net pendant. The shape of net mouth was almost a circle at 0.2m/sec and then steeply flatted elliptically with the flow velocity increasing and the area of mouth S(m super(2)) can be expressed in S=(1.65-2.3v)$\times$10 super(-2). The hydrodynamic resistance of the net increased almost linearly with the flow velocity increasing and the resistance R(kg) can be expressed in R=3.2$\times$d/l$\times$abv. where d/l denotes the mean of d(diameter of netting twine) and l(length of a leg in a mesh) from wing tip to the end of bag-net except cod-end on the side pannel, and a denotes the strectched circumference of the net at the fore end of a meshed part and b the stretched length of the whole net from wing tip to the end of cod-end. 2. In the condition-varied nets, the vertical opening of head rope showed some increase in every type net except the C type, and the increase showed the greatest in the B type by 30~54%, whereas it showed decrease in the C type by 5~10%. Variation of the area of net mouth showed almost the same tendency as the vertical opening and the increase showed the greatest in the B type by 20%, whereas it showed decrease in the C type by 12%. Hydrodynamic resistance showed some increase in every type compared with the standard net, and the rate of increase indicated 5~10% in the A-2, A-3 and A-4 type, 22% in the B type and 3% in the C type.

• Korean journal of food and cookery science
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• v.21 no.4 s.88
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• pp.440-446
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• 2005

To determine the shelf-life of low salted Myungran-jeot (low salted and fermented Alaska pollack roe), various chemical, microbiological and sensory analyses were carried out with Myungran-jeot stored at 10 days. The lactic acid content was slowly increased in the early stage of storage but then was rapidly increased with lengthening storage period, while pH was decreased during storage. The $NH_2-N$ content was steady at 10 days and peaked at 17 days. The production of VBN was increased to over $30mg\%$ at 19 days. In microbiological tests, the viable cell count and halotolerant bacteria were $1.5\times10^3\;and\;5.5\times10^3CFU/g$, respectively, at the initial state, but they slowly increased to $10^7 CFU/g$ at 17 days. Yeast or fungi did not appear on the surface of Myungran-jeot. Sensory evaluation showed that the original torture of Myungran-jeot in the mouth was a very important indicator for acceptability. Sensory characters and acceptability of Myungran-jeot at 17 days were not significantly different from those of the initial state. From these results, the estimated shelf-life of Myungran-jeot whom sealed with aluminum coated paper, was about 18 days in this study.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.175-180
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• 1998

As a part of investigation for quality improvement of surimi gel from fish with a red muscle by addition of calcium-based powder from fish bone, we investigated the processing condition of calcium-fortified mackerel surumi gel and its quality stability during storage at $5^{\circ}C$. Judging from the results of the soluble calcium content and jelly strength, the reasonable addition concentration of calcium-based powder from Alaska pollack bone for improvement of functional properties in surimi gel was revealed 0.9% on the weight basis of the chopped mackerel meat. The soluble calcium content of the calcium-fortified surimi gel (105.0 mg/100 g) was more than that of the ordinary surumi gel (2.9 mg/100 g). During cold storage of calcium-fortified surumi gel, the moisture contents, amino acid compositions, soluble calcium and phosphorus contents were little changed, the pH, volatile basic nitrogen contents, histamine contents, peroxide values and brown pigment formation were slightly increased and viable cell counts and coliform groups were not detected. The calcium-fortified surimi gel was superior in the lysine and calcium contents, EPA and DHA compositions to the ordinary surumi gel. Judging from the results, it was suggested that calcium-fortified surumi gel was nutritive, functional and safety foods.

• Journal of the Korean Society of Food Culture
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• v.18 no.2
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• pp.139-150
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• 2003

The objective of this study consists in promoting seafood consumption by increasing its intake opportunities for children through analysis of seafood using frequency in the elementary school lunch program. For that purpose, randomly sampled out from elementary schools through the county were 155 dietitians and 5th grade 3581 children, on whom a mail survey was conducted to analyse their seafood using frequency, and preference, and lunch menu by seasons. Results of this study are as follows : The seafood using frequency of the respondents represented the highest value in one or two times a week, while obstacles in seafood use presented high values in the safety of food by 71.6% and children preference by 68.4%. The seafood intake frequency of the respondents showed the highest value in three or four times a week by 34.5% and the places of seafood intake indicated the highest response in the home by 43.5% and then school lunch and dining out. The dietitians responded that children for the most part had not a preference for seafood, whereas the children pointed out average by 46.2%. As for reasons for avoidance of seafood, the dietitians expressed the highest response in it depends cooking methods by 45.8%, while the children because of its peculiar taste and smell by 42.1%. Their required improvement showed the highest response in the taste improvement by 51.8%. The children most preference for seafood that dietitians thought included fried Alaska pollack and shrimp cutlet, while dislikes braised mackerels and seasoned cold jelly fish. Cooking methods frequently used were represented in order of soup, hot soup, and stew, and the children's preferred cooking method was from fried food. Above results suggested that the intention to increase seafood using frequency is needed to at the time of planning the menus so that more seafood-providing opportunities can be given. The development of cooking methods is urgently needed that can change the taste or the smell of seafood, and concurrently with this conveniences be taken into account in eating such as elimination of bones, etc. as early as the states of purchase or checking of seafood. The reflection of the preferred cooking methods is thought to contribute to the enhancement of satisfaction with the seafood as well as to the reduction of food remnants. The recommendation of intake of low preference but nutritionally good seafood is required to be expanded in nutrition education.

• Analytical Science and Technology
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• v.23 no.6
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• pp.595-606
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• 2010

A total 221 samples of the retailed foods collected from 2004 to 2007 was examined to estimate the level of dioxins(29 congeners) by the isotopic dilution method, and the exposure of population of Korean to dietary of dioxins was performed. Dioxins levels were calculated using TEF values established in 1998 and 2005, respectively. The average levels (pg TEQ/g) were less than 0.01 for polished rice, 0.04 (poultry)-0.13 (beef) for meats, 0.04 (milk)-0.05(cheese) for milk and dairy products, 0.13 for egg (york, only) and 0.11 (alaska pollack)-1.35 (pacific mackerel) for fishes. The estimated daily intake of Korean through foods was 0.47 pg TEQ/kg bw/day, and it was estimated as about 11% to tolerable daily intake (TDI; 4 pg TEQ/kg bw/day) of Korea and Japan. Consequently, it was concluded that there was no health risk.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.274-282
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• 2002

The ethanol extract and n-hexane fraction from Hypericum ascyron L. showed strong growth inhibition at 25 ppm on 5 strains of Listeria monocytogenes for 72 hr at $32^{\circ}C$. The purified substance, H2-5-2 fraction, was isolated by silica gel column and preparative thin layer chromatography from n-hexane fraction of Hypericum ascyron L. The H2-5-2 fraction showed a strong bacteriostatic activity on 5 strains of L. monocytogenes at 10 ppm in tryptic soy broth, and the viable cell was reduced 1 log cycle compared to initial cell number. The n-hexane fraction of Hypericum ascyron L. showed strong growth inhibition at 25 ppm on Bacillus cereus and Staphylococcus aureus, and at 50 ppm on Vibrio parahaemolyticus for 72 hr. The purified antimicrobial substance, the H2-5-2 fraction, was assumed as high unsaturated sterol by $^1H-NMR$ and $^{13}C-NMR$. On application test using minced Alaska pollack and ground beef, the n-hexane fraction of Hypericum ascyron L. at the level of 250 ppm was applied at $32^{\circ}C$ and $5^{\circ}C$. At $32^{\circ}C$ storage condition, the antimicrobial substances did not reduced L. monocytogenes ATCC 19113, meanwhile at $5^{\circ}C$ storage condition, L. monocytogenes ATCC 19113 was reduced in viable number.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.769-776
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• 2003

Organic acids, nucleotides and their related compounds (NRCs) of kimchi prepared with salted-fermented fish products (SFFPs) and their alternatives were analyzed at each optimal fermentation (pH $4.2{\pm}0.2$, acidity $0.6{\sim}0.8%$) during fermentation at 20, 10 and $4^{\circ}C$, respectively. The pH and acidity levels of kimchi sharply decreased and increased, respectively until each optimal fermentation period. The levels of organic acids and NRCs in SFFP kimchi were affected by fermentation temperature and the type of additive. Compared with the control, organic acid levels were slightly higher in kimchi with alternative additives, as were NRC rates in kimchi with hydrolysates of oyster and Alaska pollack. Moreover, slightly higher levels of NRC were observed in kimchi with alternative additives than in kimchi with SFFPs. Consequently, these results show that fermentation temperature and the type of additive (SFFPs and their alternatives) affect not only fermentation, but the levels of organic acids and NRCs in kimchi.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.459-465
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• 1997

In order to extend the shelf-life of the low-salted Myungran-Jeot, before immersing alaska pollack roe, the salt solutions was adjusted to pH 7.0 and 4.7, respectively. pH during ripening was somewhat constant, whereas the content of lactic acid was slightly increased, and especially, that of pH 4.7 Myungran-Jeot was increased rapidly in the begining of fermentation period. $NH_2-N$ content of pH 4.7 Myungran-Jeot was increased with increasing fermentation period, whereas those of control and pH 7.0 decreased except the begining of fermentation period. The contents of TMA, TBA, and VBN of pH 4.7 were lower than those of control and pH 7.0. In addition, the mirrobial growth was significantly inhibited in pH 4.7 Myungran-Jeot. The estimated shelflives of control, pH 7.0, and pH 4.7 Myungran-Jeots were about 12, 12, and 16 days, respectively.