• Journal of Biosystems Engineering
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• 제41권4호
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• pp.365-372
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• 2016

Purpose: Tea is the most frequently consumed drink worldwide, next to water. About 75% of the total world tea production includes black tea, and withering is one of the major processing steps critical for the quality of black tea. There are two types of tea withering methods: physical and chemical withering. Withering can be achieved by using tat, tunnel, drum, and trough withering systems. Of these, the trough withering system is the most commonly used. This study focuses on the different types of withering, their effect on the various quality attributes of tea, and other aspects of withering methods that affect superior quality tea. Results: During physical withering, tea shoots loose moisture content that drops from approximately 70-80% to 60-70% (wet basis). This leads to increased sap concentration in tea leaf cells, and turgid leaves become flaccid. It also prevents tea shoots from damage during maceration or rolling. During chemical withering, complex chemical compounds break down into simpler ones volatile flavor compounds, amino acids, and simple sugars are formed. Withering increases enzymatic activities as well as the concentration of caffeine. Research indicates that about 15% of chlorophyll degradation occurs during withering. It is also reported that during withering lipids break down into simpler compounds and catechin levels decrease. Improper withering can cause adverse effects on subsequent manufacturing operations, such as maceration, rolling, fermentation, drying, and tea storage. Conclusion: Freshly harvested leaves are conditioned physically and chemically for subsequent processing. There is no specified withering duration, but 14-18 h is generally considered the optimum period. Proper and even withering of tea shoots greatly depends on the standards of plucking, handling, transportation, environmental conditions, time, and temperature. Thus, to ensure consumption of high quality tea, the withering step must be monitored carefully.

• Journal of the Korean Society of Food Culture
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• 제10권1호
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• pp.11-17
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• 1995

The changes in life style these days appear in many ways. Many housewives turn away from home preparation of the time consuming traditional foods, such as Andong Sikhe. The importance, however, of succeeding the traditional cuisines is getting appreciated widely now a days. A traditional Andong Sikhe in Korea, was prepared and fermented at $5^{\circ}C$ in order to analyze the taste and flavor compounds. Major flavor components were identified as camphene, sabinene, 1-(1,5-dimethyl-4-hexyl)-4-methyl-benzene, ${\alpha}-zingibirene$, farnesene, 2,6-bis(1,1-dimethylethyl)-4-methyl-phenol, ${\beta}-sesquiphellandrene$, calalene, tetradecanoic acid, hexadecanoic acid and 9,12-octadecanoic acid by GC and GC/MS. Lactic acid and increased from 0.49 mg/100 g in the initial stage to 19.37 mg/100 g at the 6 days of storage. The pH of product decresed to 3.7 from 5.4 after the 6 days of storage but the total acidty reached to 0.41% during fermentation and storage at $5^{\circ}C$.

• Applied Biological Chemistry
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• 제41권7호
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• pp.510-515
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• 1998

Effect of freezing of soybean and addition of mugwort on the flavor development and the changes of chemical compositions in Chungkookjang was investigated. The changes in the amount of amino-type N, the activities of ${\alpha}-amylase$ and protease, and the content of volatile compounds were determined during aging of Chungkookjang. During ripening, a little higher protease activity was detected in Chungkookjang made of frozen soybean than in that made of non-frozen soybean. However, the profile of ${\alpha}-amylase$ activity of Chungkookjang made of frozen soybean was very similar to that of Chungkookjang made of non-frozen soybean. The amount of amino-type N increased gradually with the ripening period and decreased after 21 days of ripening. The amount of amino-type N was slightly higher in Chungkookjang made of frozen soybean than in that made of non-frozen soybean. Addition of mugwort had little effect on the enzyme activities and the amino-type N content. The mugwort added in Chungkookjang reduced the production of cis-3-hexenol which is responsible for the unpleasant odor, and freezing of soybean enhanced the production of 2, 6-dimethyl pyrazine which is contribute to the taste. According to sensory evaluation, flavor was the highest after the 14 days of ripening and addition of mugwort increased significantly the flavor in both Chungkookjang prepared with frozen soybean and Chungkookjang with non-frozen soybean. However, the effect of freezing of soybean on the flavor was not significant.

• Journal of the Korean Society of Food Science and Nutrition
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• 제44권4호
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• pp.564-572
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• 2015

Nutritional compositions, volatile compounds, and sensory attributes of Cynanchi wilfordii Radix were analyzed in order to examine its practical utilization as a food resource. In the proximate analysis, protein and lipid contents were shown to be 14.6 and 5.0 mg/100 g, respectively, in C. wilfordii Radix. Potassium was the most predominant mineral (809 mg/100 g), as determined by inductively coupled plasma-optical emission spectrometry in parallel with microwave acid digestion. Total phenolic content was found to be 410 mg/100 g. Further, arginine and linoleic acid were the most abundant amino acid and fatty acid of C. wilfordii Radix, respectively. To examine its functional properties, classical 2,2-diphenyl-1-picrylhydrazyl (DPPH) analysis was performed. As a result, the concentration of C. wilfordii Radix required to scavenge 50% of DPPH radicals was 1.16 mg of dried material. Lastly, in olfactory and sensory tests, ${\beta}$-eudesmol (woody odor) was the major flavor compound responsible for the bitter taste and sensory attributes of C. wilfordii Radix. Taken altogether, the above results provide important preliminary results for utilization of C. wilfordii Radix as a food resource.

• Korean Journal of Food Science and Technology
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• 제30권1호
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• pp.54-61
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• 1998

Samjangs (Korean-style mixture of soybean paste) were prepared using magjang, traditional doenjang (Korean style soybean paste), and mixture of traditional doenjang and magjang (a kind of Korean style soybean paste) as a main composition. Charateristics including volatile compounds were investigated. Total sugar in samjang by using magjang was higher than that of other treatment while reducing sugar of the mixed treatment was high. Glutamic acid $(230.6{\sim}310.9\;mg/100\;g)$ was highest among free amino acids. Hunter color values of samjang with magjang was lower than those of others. Volatitle flavor components of smajang were identified with GC and GC-MSD. Fifty four components including 11 alcohols, 7 esters, 13 acids, 3 aldehydes, 4 alkanes, 4 phenols, 3 pyrazine and others were found in samjangs. Ethanol, acetic acid ethyl ester, 3-methyl butanoic acid, 2,4-hexadienoic acid and acetic acid might be major volatile components considering of high peak area. Pentanoic acid methyl ester and 4-methoxy-2-buten-1-ol were higher than other components in samjang with magjang while 2-methyl-1-propanol, butanoic acid and 3-methyl butanoic acid were in samjang with traditional doenjang and ethanol, acetic acid ethyl ester and 2,4-hexadienoic acid were in the mixed treatment.

• Korean Journal of Food Science and Technology
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• 제5권3호
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• pp.183-187
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• 1973

Soong-Neung is a Korean traditional beverage served after meals and is made from Soong-Neung producing rice (Noo-Roon-Bap) which is cooked and toasted rice produced on the bottom of the container during the rice cooking process. In order to study the chemical changes occurring in Soong-Neung producing rice with temperature$(20{\sim}220^{\circ}C)$ during the cooking process, thermal analysis, total sugars, total nitrogen, reducing sugars, water soluble nitrogen, total acid, carbonyl content, phenolic compounds were determined. Thermal analysis showed that decrease of weight and endothermic reaction caused by evaporation of water in the sample appeared at $95{\sim}130^{\circ}C.$ The production of volatile compounds increased gradually beginning at $130^{\circ}C$, however, those compounds increased markedly at $160^{\circ}C$ and above. Maximum absorption of ultraviolet spectra of an aqueous distillate occurred at about $273m{\mu}$. Organoleptic analysis showed that an acceptable flavor was produced in the temperature range of $125{\sim}155^{\circ}C.$

• The Korean Journal of Food And Nutrition
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• 제19권4호
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• pp.466-472
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• 2006

In order to develop materials of crab-like flavorant, taste compounds including physicochemical characteristics were analyzed in red snow crab cooker effluent(RSCCE) and hepatopancreas. The $30\;^{\circ}Brix$ was a suitable condition in from 1.5 to $40\;^{\circ}Brix$ RSCCE by sensory evaluation. Lactic acid and succinic acid were major compounds in non-volatile organic acids detected in both $30\;^{\circ}Brix$ RSCCE and hepatopanceras. The 5 compounds such as AMP, HxR, IMP, ATP and GMP were major in ATP related compounds of $30\;^{\circ}Brix$ RSCCE, whereas 3 compounds including IMP, GMP and Hx in hepatopanceras. The content of total free amino acids in hepatopancreas was 5.6 times higher than in $30\;^{\circ}Brix$ RSCCE. The major compounds in $30\;^{\circ}Brix$ RSCCE were followed by methionine, lysine, arginine, valine, histidine, alanine, hydroxy proline, and glycine in that order, whereas methyl histidine, leucine, alanine, glutamic acid, glycine, valine, threonine, taurine, isoleucine, and serine were followed in hepatopancreas. By adding 0.5%(w/w) hepatopancreas in $30\;^{\circ}Brix$ RSCCE, crab meat-like odor was kept high level by sensory evaluation.

• Korean Journal of Food Science and Technology
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• 제20권6호
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• pp.774-779
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• 1988

The essential oil of Artemiisa lavandulaefolia DC was analyzed by gas chromatography/mass spectrometry (GC/MS). The oil was stored at different conditions for 6 weeks and the changes of color and chemical composition during storage were checked by GC/MS. The experimental results were as follows; (1) More than 186 chemicals were detected by GC. Major components were 1,8-cineol, thujone, camphor, borneol, coumarin, 2,3-dihydrobenzofuran and ${\beta}-biasbolene$. In this study, 3,3,6-trimethyl norpinanol, ${\beta}-farnesene,\;{\alpha}-curmene$ and 7-methoxy coumarin were detected as new compounds in Artemisia species. (2) It was proved that temperature and/ or light had and important effect on the changes of color and volatile components of the essential oil. The relative amounts of limonene and 1.8-cineol were decreasad, on the other hand, ${\beta}-phellandrene\;and\;{\alpha}-terpineol$ were increased during storage.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제50권6호
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• pp.656-661
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• 2017

To develop a highly value-added product from extract from small and damaged sea mussels Mytilus edulis, we prepared two types of sea mussel sauce (MS): bottled (BMS) and retort pouched (RMS). We investigated the processing conditions, quality metrics and flavor compounds in each type of sauce. We found that the most appropriate base formulation for both BMS and RMS consisted of 40.0% SME (Brix $30^{\circ}$), 15.0% sugar, 6.0% salt, 4.0% monosodium glutamate, 4.0% soy sauce, 3.5% starch, 3.0% yeast extract, 3.5% wheat flour and 21.0% water. The crude protein, salinity, volatile basic nitrogen and amino-nitrogen content of the BMS and RMS were 8.7% and 8.8%, 9.3% and 9.2%, 24.9 and 31.4 mg/100 g, and 468.5 and 455.1 mg/100 g, respectively. For comparison, the ranges of these values in commercial oyster sauces (COS) are 4.7-7.5%, 10.7-12.0%, 8.2-12.5 mg/100 g, and 225.7-448.2 mg/100 g, respectively. The total free amino acid content of RMS and Premium COS was 7,215.7 and 6,160.7 mg/100 g, respectively, and the main free amino acids were glutamic acid, taurine, glycine, alanine, arginine, proline and lysine. These results demonstrate that BMS and RMS have favorable organoleptic qualities and good storage stability compared to COS, and are suitable for commercialization as high-flavor seasoning sauces.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제15권8호
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• pp.5176-5185
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• 2014

This study was conducted from 2010 to May 2012 to determine the volatile flavor compositions, biological activity and components of A. monanthum from different regions in Korea. The flavors of A. monanthum were extracted by SPME methods and it contained forty-two compounds that included mainly hydrocarbons and acids. The cancer cell growth inhibition activities of A. monanthum on the cancer cell (HaCaT, HepG2, HCT116, PC3) line were increased in a dose-dependent manner and the hexane fraction showed the highest antiproliferation effects. A. monanthum also showed the highest antioxidant activity. The results suggest that A. monanthum can be used as bioactive and functional materials.