• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.349-354
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• 2019

In this study, 30 kinds of long-term and mature Korean soy sauce were collected and classified by the fermentation period, and the components related to taste and sensory characteristics were analyzed. A total of 4 kinds of organic acids were detected. The total organic acid content was in the range of 97.2~341.6 mg%, but did not show the tendency to increase or decrease in proportion to the aging period. The total free amino acid content was within the range of 3,001.0~3,834.7 mg% and showed a tendency to increase in proportion to the ripening period of the soy sauce. The contents of aspartic acid and glutamic acid subsequently increased in the long-term matured soy sauce. The ratio of essential amino acid to total amino acid was 31.6~35.7%, and the ratio of glutamic acid to total amino acid was 19.6~23.9%, respectively. The panel of 20~29-year-old indicated that the longer the aging period of soy sauce, the lower the preference while the panel of 30 or more years indicated that the longer the aging period of soy sauce, the higher the preference. This study was the first to investigate the quality of long-term matured soy sauce in more than one year.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.4
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• pp.57-62
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• 2011

As NPPs' operating times increase, the integrity of nuclear components is continually degraded due to aging effects of systems, structures and components. In addition, for the case of continued operation beyond design life, additional aging effects occurred during the extended operating period lead to more degradation of the integrity of nuclear components. Therefore, it is very important to mange and evaluate the aging to secure the safety of NPPs. Wolsong unit 1 is approaching to its design life of 30 years in 2012. The license renewal documents for continued operation of Wolsong unit 1 Is under reviewing now. In this paper, regulatory technologies for continued operation of Wolsong unit 1 developed by KINS will be introduced. That technologies include the safety review guidelines, regulatory guides for aging management program and regulatory program for audit calculation.

• Food Science of Animal Resources
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• v.36 no.2
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• pp.159-169
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• 2016

Animal muscles are stored for specific period (aging) at refrigerated temperatures, during and after which the living muscles start to convert into meat and thus, attain certain superior properties in the final product. Proteolysis, lipolysis, and oxidation are the major biochemical processes involved during the postmortem aging of meat that affect the tenderness, juiciness, and flavor, as well as sometimes may introduce certain undesirable traits. This review analyzes the role of pre- and post-mortem factors that are important for aging and their effect on the chemical and physical changes in the “dry- and wet-aged meat.” Thus, if the meat processing manufacturers optimize the effects of aging for specific muscles, the palatability, color, and the shelf life of the aged meat products could be significantly enhanced.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.720-728
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• 2014

In order to characterize the quality of Doenjang, fermented Korean soybean paste, subjected to long-term aging, this study performed physico-chemical analyses and sensory evaluation according to aging period (from 1 to 9 years). Regarding the proximate composition of Doenjang according to aging period, moisture, crude protein, crude lipid, crude ash, and salt contents showed little differences among Doenjang samples. Amino-type nitrogen content was 1,046.7 mg% in the 1 year-aged sample, 990.9~996.9 mg% in the 2~5 year-aged samples, and 1,214.1~1,304.8 mg% in the samples fermented more than 5 years. ${\Delta}$E value, reflecting total color differences between the samples, increased according to aging period. Ratios of linoleic and linolenic acids, which are essential fatty acids in soybeans, constituted 55% of total fatty acids, which was the most abundant among all fatty acids. The major free sugar in Doenjang was fructose at a content of 1.6~2.2% in 1~9 year-aged Doenjang. Glycoside form of isoflavones in Meju constituted 77.1%, and the aglycon form constituted 22.9%. However, the glycoside type of isoflavones in soybeans was converted to aglycon type in Doenjang through fermentation and aging. In the sensory evaluation of Doenjang samples, brown color, salt smell, soy sauce flavor, and viscosity all increased according to aging period, whereas sweet flavor, roast smell, beany flavor, salty taste, and acrid taste showed no significant differences. In cluster analysis of the sensory attributes of Doenjang according to aging period, 1 year-aged Doenjang was significantly different between 2 year- and 3~5 year-aged Doenjang.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.225-232
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• 1986

This study was to improve the quality of Kochuzang and utilize red pepper seed. Kochuzang were prepared with the addition of red pepper seed and garlic (2％), compared the changes in the various chemical components and enzyme activity during the aging period of Kochuzang, and also organoleptic values of the products. Enzyme activities of liquefying and saccharogenic amylase, protease and lipase were increased by addition of garlic pulp and the suvival activities of enzyme except liquefying amylase were lasted high the late period of aging. Also the addition of red pepper seed was effective in maintaining the enzyme activities Change of titration acidity and pH of kochuzang were little when red pepper seed was added, but in case of a garlic additive it showed no difference at the late period of aging. Total nitrogen and amino nitrogen were increased by the addition of red pepper seed or garlic until the late period of aging, and ammonia nitrogen also increased during the middle period of againg, but showed no difference at the late period. Alcohol content was decreased by the addition of garlic or red pepper seed. but crude lipid was increased by the audition of red pepper seed. but crude lipid was increased by the addition of red pepper seed. Generally, taste, flavor and color of garlic added group were superior to the non-garlic added group for the products which aged for 10 weeks. Therefore, The quality of Barley Kochuazng may be improved by adding 2％ garlic to the whole red pepper.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.105-108
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• 2018

Beef was dry aged for 40-60 days under controlled environmental conditions in a refrigerated room with a relative humidity of 75%-80% and air-flow. To date, there is little information on the microbial diversity and characteristics of dry aged beef. In this study, we explored the effect of change in meat microorganisms on dry aged beef. Initially, the total bacteria and LAB were significantly increased for 50 days during all dry aging periods. There was an absence of representative foodborne pathogens as well as coliforms. Interestingly, fungi including yeast and mold that possess specific features were observed during the dry aging period. The 5.8S rRNA sequencing results showed that potentially harmful yeasts/molds (Candida sp., Cladosporium sp., Rhodotorula sp.) were present at the initial point of dry aging and they disappeared with increasing dry aging time. Interestingly, Penicillium camemberti and Debaryomyces hansenii used for cheese manufacturing were observed with an increase in the dry aging period. Taken together, our results showed that the change in microorganisms exerts an influence on the quality and safety of dry aged beef, and our study identified that fungi may play an important role in the palatability and flavor development of dry aged beef.

• The Korean Journal of Community Living Science
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• v.19 no.3
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• pp.365-371
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• 2008

This study was conducted to determine the potent physiological activity of traditional wild tea ("Don tea"; coin-shaped tea) as affected by different harvesting times, aging periods and extracting temperatures, No difference in anti-oxidative activities in the harvesting time and extracting temperature of tea leaves was observed. However, short aging periods of Don tea showed high ABTS {2-2-azonobis (3-ethylbenzothiazolin-6-sulphonic acid)} activity, ranging from 71.52 to 79.96%. DPPH (${\alpha},\;{\alpha}-diphenyl-{\beta}-picryl-hydrazyl$) radical scavenging activity of Don tea was 71.10 to 91.40%. Especially, longer aging period and an extracting temperature of $100^{\circ}C$ showed higher DPPH radical scavenging activity. With longer aging periods and an extraction at $90^{\circ}C$, nitrite radical scavenging activity of Don tea ranged from 74.04 to 94.92%. On the other hand, angiotensin 1-converting enzyme (ACE) inhibition activity of Don tea was 59.77-81.97%. It showed higher activity when harvested in June and August, aged for longer periods, and extracted at $100^{\circ}C$. These results suggested Korean traditional Don tea exhibited the highest physiological activity when aged over 8 months.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.570-585
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• 2024

This study focused on understanding the effects of yeast and mold on the sensory properties of dry-cured ham aged at 20℃ and 25℃. Debaryomyces hansenii isolated from Doenjang and fermented sausages, and Penicillium nalgiovense isolated from fermented sausages were utilized. The CIE a^* tended to increase in all treatments as the aging period increased. At 6 weeks of aging, DFD25 showed a significantly higher CIE a^* value than other treatments. The shear force tended to increase in all treatments as the aging period increased. At 6 weeks of aging, among the treatments aged at 25℃, DFD25 showed a low tendency to shear force. The PC1 of the electronic nose was 42.872%. At 25℃, the hexane content was higher and levels of ethanol, propan-2-one, 2,4,5-trimethylthiazole, and limonene were lower than that at 20℃. DFD25 showed significantly higher hexane content and significantly lower limonene content than other treatments. The PC1 of the electronic tongue was 84.529%. All treatments, except for the C starter, exhibited higher salt and lower sour levels at 25℃ compared to 20℃ when the same starter was used. The DFD25 showed the lowest sour taste and a higher tendency of umami than the other treatments. Sensory evaluation revealed that DFD25 had significantly higher scores for texture than C25, whereas no significant differences were observed in other aspects. Therefore, the used starters are considered suitable for aging at 25℃; among them, the DFD starter demonstrates superior qualities and enhanced commercial potential compared to the control.

• Nuclear Engineering and Technology
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• v.40 no.4
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• pp.277-284
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• 2008

Recently, the long-term operation of a nuclear power plant beyond its licensed term has become a worldwide trend as long as the safety of the plant is maintained in the extended period. Kori Unit 1, the oldest PWR in Korea, is the foremost example of this type of long-term operation in Korea. Comprehensive technical evaluation of the long-term operation of this plant was completed to confirm the overall safety of the plant. The technical evaluation included a review of PSR results, an assessment on aging management programs and time limited aging analyses, and a statement of radiological impact on the environment. Based on all of the results of the technical evaluation activities, Kori Unit 1 was approved to operate for an additional 10 years beyond its original design life of 30 years.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.1
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• pp.41-48
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• 2016

To investigate the effect of long-term thermal aging on the microstructural and mechanical characteristics of weldment made of nickel base alloy and its weld metal, an accelerated heat treatment was applied to simulate the process of long-term thermal aging in the operating condition of nuclear power plant. A representative nickel-based weldment with Alloy 600 and Alloy 182 was fabricated and heat-treated at $400^{\circ}C$ for 1,713 h and 3,427 h to simulate the thermal aging for the period equivalent to 15 and 30 years in operating pressurized water reactors, respectively. The microstructural and mechanical characteristics were analyzed by using optical microscopy, scanning electron microscopy and Vickers microhardness measurement. Changes were observed in precipitation behavior and microhardness of each specimen, and these changes were mainly attributed to the change in precipitated morphology and residual stress across the weld during the thermal aging process.