• Applied Biological Chemistry
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• v.51 no.4
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• pp.281-287
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• 2008

Effect of combined use of anti-microbial materials, such as alcohol, mustard and chitosan, or pasteurization on the quality of low salted kochujang was investigated during storage at $30^{\circ}C$ for 12 weeks. Activity of amylase decreased during storage, with lower activity in pasteurized kochujang than the other groups. Acidic protease activity increased during storage, but neutral protease activity decreased after 4 weeks. Viable cells of yeast increased during storage, but bacterial counts decreased gradually and did not show any remarkable difference among the test groups. Hunter a-values decreased as storage time increased, whereas L- and b-values decreased after 4 weeks and the degree of increase in total color difference (${\Delta}E$) was low in the supplementary ingredients added kochujang. The moisture contents and water activities decreased during storage with being lower in supplementary ingredients added groups. Titratable acidity of kochujang was decreased after 4 weeks of storage with the highest in combination of the supplementary ingredients added group. Oxidation-reduction potential was low in the supplementary ingredients added kochujang. Total sugar and reducing sugar contents of kochujang decreased during storage, with the highest contents in the supplementary ingredients added group. Ethanol content of kochujang increased during storage, whereas ethanol production was reduced in ethanol added one. Amino-nitrogen and ammonia-nitrogen contents decreased during storage with being lower in kochujang prepared with supplementary ingredients. Therefore, supplementary ingredients added kochujang would be effective for extending shelf-life of kochujang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1596-1603
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• 2007

This study was conducted to improve functional properties of salmon frame extracts using various commercial enzymes (Alkalase 2.4 L FG, Flavourzyme 500 MG, Neutrase 0.8 L and Protamex 1.5 MG). The ACE (angiotensin I converting enzyme) inhibitory activity was the highest ($IC_{50}=0.67mg/mL$) in the product incubated with Neutrase for 4 hrs (N4-treated hydrolysates) among the various extracts incubated with commercial enzymes for different times. However, antioxidant activities of all salmon frame extracts were less than 15%. There were no significant differences in the proximate composition and sensory evaluation of the fish odor and taste. However, N4-treated hydrolysate was improved in the extractive-nitrogen content and transmission compared to the other enzymatic hydrolysates. When compared to commercial Gomtang products, N4-treated hydrolysate was also high in protein, extractive-nitrogen, total amino acid, and calcium contents, while low in taste sensory score. There were no differences in transmission and sensory score on the fish odor between N4-treated hydrolysates and commercial Gomtang.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.876-883
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• 1989

In order to investigate the index component and basis for the shelf-life of the grain share improved Meju, the effect of the storage time and package on the quality of Meju and soy sauce were studied during 90 days storage at $30^{\circ}C$. Also, sensory evaluation for the soy sauces from Meju with various storage time were carried out. During the storage period, moisture content, amylase and protease activity were decreased, on the other hand, the contents of amino-nitrogen and ammonia-nitrogen were increased. Among these components, protease activity was found the major index component for quality control because it was the most important component for soy sauce fermentation and the most changeable component of Meju during the storage period. According to the sensory test, the quality of soy sauce was agreed well with the protease activity of Meju, and the soy sauce from longer storage Meju was inferior organoleptic quality to that from shorter Meju. By the storage quality test, protease activity showed the highest value in 15 days storage Meju and decreased gradually with storage time passed. The basis of protease activity for quality control was 200 (O.D. at 660 nm/g). which was 50% of the initial activity And it was known that the shelf-life of the grain shape improved Meju was about 90 days . It was also shown that the storage in package did not affect noticeably to prolong the shelf-life of Meju on this study.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.321-329
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• 1993

The present study was conducted to elucidate the body modulating function of fermented seafood products. Angiotensin converting enzyme (ACE) acts in blood pressure regulation, converting angiotensin I to the potent vasoconstrictor angiotensin II and inactivating the vasodilator bradykinin to raise blood pressure. Salted and fermented anchovy which is one of the traditional fermented seafood in Korea was tested for inhibitory activity against ACE. ACE inhibitory activity of salted anchovy during the period of fermentation was increased with the elapse of fermentation days until fermentation of 60 days, but thereafter decreased inversely. When the fermented product was extracted with $50\%$ ethanol, the ACE inhibitory activity was the highest. And the ACE inhibitory activity was proportion to the content of $50\%$ ethanol soluble peptide-nitrogen of the fermented product. From the profiles of gel permeation chromatography on a Bio-Gel P-2 of $50\%$ ethanol soluble fraction obtained from salted and fermented anchovy fermented for 60 days at an ambient temperature, the higher activity fractions were C'($IC_{50}=97{\mu}g\;protein/ml$) and D'($IC_{50}=65{\mu}g\;protein/ml$). Amino acid analysis showed that the large quantify of threonine, glutamic acid, lysine for C' and serine, proline for D', respectively.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1427-1433
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• 1999

The Microbiological, chemical and sensory analyses were carried to evaluate the quality of commercial salted and fermented seafoods and to establish a standardization. The results showed that amino nitrogen(AN) and volatile basic nitrogen(VBN) contents were appropriate in evaluating the quality of shrimp jeotkal. In the range of $150{\sim}300\;mg%\;and\;25{\sim}70\;mg%$, AN and VBN contents were highly correlated to sensory scores, respectively. In the case of squid jeotkal, pH and VBN contents were appropriate to evaluate quality. The coefficients of the correlation between pH and sensory evaluation was 0.84 and the sensory acceptability was high and above pH 6.0. In addition, the coefficients of the correlation between VBN contents and sensory evaluation was 0.95, and the sensory acceptability was high but below 30 mg%. In the case of shell-fish jeotkal, the coefficient of the correlation between VBN content and sensory evaluation was 0.94, and sensory acceptability was high but below 40 mg%.

• Korean Journal of Food Science and Technology
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• v.13 no.4
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• pp.319-327
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• 1981

In order to reproduce and improve the Korean traditional Kochujang(fermented hot pepper-soybean paste), traditional and improved Kochujang Koji were prepared according to the standard method investigated in Chunrabookdo area and combined the raw materials of Kochujang by the traditional habit. Amino nitrogen contents were higher in improved Kochujang than in traditional one, those were in the range from 83 to 106 mg% immediately after brewing and 191 to 313 mg% at the end stage of brewing. Water soluble and ammonia nitrogen contents were most high in the improved Kochujang which was mixed with sodium chloride and brewed soysauce as seasoning. The content of reducing sugar of traditional Kochujang was higher than that of improved one during the brewing. Ethyl alcohol contents of all Kochujang samples were 0.04% at the early stage of brewing and that reached above 2.5% after $40{\sim}50$ days brewing.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.570-576
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• 2002

For the utilization of the by-products of whelk processing, whelk internal organ with the addition of commercial proteolytic enzymes - Flavourzyme, Neutrase, Protease NP, Prozyme - were used to make jeotgal, Korean traditional salted and fermented seafood sauce. The products were prepared at salt concentration of 25% with enzyme contents 0.05 and 0.1%. The samples were stored at $10^{\circ}C$ and the chemical properties were evaluated for 6 months. The pH in all samples were decreased from near 6.8 in the beginning stage to 6.1-6.4 in the final stage of incubation. Amino nitrogen of jeotgal increased with enzyme concentration and showed maximum value, 646 mg%, at 0.1% of Flavourzyme. Total nitrogen content was increased till four months, but rapidly decreased after that. Protein degradations of whelk internal organ during maturation of jeotgals were investigated by SDS-PAGE. The patterns of degradation were different with added enzymes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.139-147
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• 1991

The preservative effect of cellophane film packing on the quality of semi-salted and dried mackerel was studied. The product(P) of semi-salted and dried mackerel was prepared from raw mackerel by filleting, cleaning, soaking in 15%9v/w) salt solution for 30min, draining, packing with cellophane film (PT# 300, thickness:$20{\mu}{\textrm}{m}$) and drying for 4 hrs at $40^{\circ}C$ in hot air dryer. The product (C) was also prepared without cellophane film packing after draining. The product (C) and (P) were stored at $5.0{\pm}0.5^{\circ}C$. After processing and during storage, moisture content of product (P) was higher than that of product (C), but contents of VBN(volatile basic nitrogen), amino nitrogen and TMA of product (P) on dry basis were lower than those of product (C). Viable cell count, TBA value, peroxide value and decreasing rate of polyenoic acid of product (P) were also lower than those of product (C). In sensory evaluation, the shelf life of product (C) was about 9 days and that of product (P) was about 14 days. From the results of chemical and sensory evaluation, it was concluded that cellophane film packing was a good condition for preserving the quality of semi-salted and dried mackerel.

• Korean Journal of Agricultural Science
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• v.16 no.2
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• pp.179-200
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• 1989

Mucor miehei rennet(MR) was added as calf rennet(CR) substitutes in the fixed amounts of mixed rennets in making Camembert cheese. The conditions in the variations of chemical composition: water-soluble nitrogen, non-caseinic nitrogen, non-proteinic nitrogen, amino nitrogen, ammoniacal nitorgen, electrophoresis, molecular fractionation, mineral distribution, texture characterisitics, free amino acids and free fatty acids, were checked up with the sensory test and the chesse yields at each ripening period. The results obtained by investigating the utility of Mucor rennet were summarized as follows: 1. CR chesse, MR cheese and the mixed-rennet chesse failed to show any significant difference in their yields of 15%. 2. The contents of protein, fat and ash in MR cheese gave lower value than CR cheese did and with progress of ripening lactose decreased rapidly after 14 days of ripening. The difference among the rate of addition of mucor rennet was not recognized. 3. The WSN contents of 5 fresh sample chesse were from 14.7% to 17.3% and WSN increased from 39.7% to 41.0% with progress of ripening. After 21 days of ripening MR chesse had more WSN than CR cheese did. In NCN and ammoniacal nitrogen MR cheese showed higher value. 4. As the ripening progressed, MR chesse showed more cystein, phenylalanine and proline than CR chesse did but it failed to show any increase in aspartic acid, threonine and glutamic acid etc. 5. In the content of free fatty acid MR chesse showed higher value than CR cheese did and with the progress of ripening fatty acids increased from 8.36 mEq to 26.36 mEq but did not show any significant difference in the cheese types by the coagulant ratio. 6. Ca contents in the sample chesse were 0.238-0.27%, Mg 0.019-0.022%, Na 0.910-1.047%, and K 0.175-0.200%. The important non-sedimentable Ca in casein remained from 61 % to 77% without regard the ripening periods and added-rennets and Mg remained from 59.1% to 92.5% in non-sedimentable and water-soluble conditions. 7. In the fractionation of protein by ultrafilteration, MW> $5{\times}10^4$ decresed from 95% at the beginning period of ripening to 45% and MW< $10^4$ increased from 0.2% to 38% and definite caseinolysis was shown in all samples. 8. All the cheese showed to different electrophoretic patterns for the added-amounts of mucor rennet in the 14 days of ripenig. In the 28 days or ripening, MR cheese kept some bands on the patterns compared with CR cheese. 9. In vitro digestibility increased from 81.48-94.81 % to 94.47-98.61% but failed to show any significant difference in the cheese types by the coagulant ratio. 10. In hardness, MR cheese showed lower value compared with CR cheese as the ripening progressed. 11. The results of the sensory test failed to show any difference in flora rind, feelings in mouth and hands, deep structure, flavor and bitterness between CR Camembert cheese and MR Camembert chesse.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.38-44
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• 2005

In addition to the variation in nitrate accumulation of vegetables due to environmental conditions, there is also a distinct genetic variation. The variation of nitrate accumulation in some cultivars of lettuce and spinach commonly cultivated in Korea was investigated. Ten cultivars for both lettuce and spinach were grown in plastic containers filled with a 1:1 mixture of perlite and vermiculite with application of Hoagland No. 2 nutrient solution of high nitrate content (17.3 mM N) in a greenhouse condition. Plants were harvested four weeks after transplanting four-leaf stage seedlings. Plant growth was measured by fresh and dry matter of shoot, and contents of nitrate and other inorganic ions and organic solutes including sugar, amino acids and organic acids were measured. Large and significant genotypical variations in the nitrate content of the plants were found for both lettuce and spinach, and high negative correlations between nitrate content and fresh or dry weight were found in lettuce and spinach. Variation in nitrate accumulation of lettuce and spinach cultivars was not directly related to the differences in contents of organic and inorganic solutes, and this result indicates that photosynthesis and osmotic regulation are not directly related with the nitrate accumulation. Considering the correlations between nitrate content and plant growth of this study, it can be simply suggested that different cultivars of lettuce and spinach have their own inherited growth and physiological characteristics and also optimum nitrogen level required for the growth. Therefore when available nitrogen in root media is higher than the optimum level required for the inherited growth potential, some of the excess nitrate supplied can be accumulated in plants.