• KSBB Journal
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• v.4 no.1
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• pp.40-47
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• 1989

Changes of principal components of crude green tea were determined after 30 min. of heat treatment at 10$0^{\circ}C$, l15$^{\circ}C$, 14$0^{\circ}C$, 16$0^{\circ}C$. Four kinds of free sugars(sucrose, fructose, glucose, raffinose) and an unidentified sugar compound were separated in green tea by using High Performance LiQuid Chromatography (H.P.L.C.). 26-34 peaks were isolated as aroma compounds of green tea by means of Gas Liquid Chromatography(G.L.C). The typical aroma component of green tea such as linalool, furfural, benzyl alcohol and 13 other substances were identified. Contents of most compounds were decreased by heat treatment. Especially contents of free amino acids, free sugars, vitamin C and tannins were decreased remarkably, while those of total nitrogen and soluble nitrogen were hardly changed. The effect of heat treatment on organoleptic quality of tea extracts were examined by sensory evaluation of which result indicated the most favorable tea was produced at 115$^{\circ}C$. The Percentages of loss in contents of total sugars, reducing sugars, vitamin C, free amino acids and tannins at 115$^{\circ}C$ were 17%, 16%, 36%, 12% and 15% respectively, while those were 38%, 53%, 55%, 74% and 23% at 16$0^{\circ}C$.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.297-303
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• 2011

The contents of capsaicinoid, free sugars and organic acids of six varieties of Korean hot pepper, Supermanita, Dokyacheongcheong, Shinseokyeoi, Wangdaebak, Hanbando, and Chungyang, were measured. The sensory evaluations of its extracts were compared in order to investigate the indirect effect or reaction of the composition of taste components on sensory acceptability of Korean hot pepper. The contents of capsaicinoid were considerably from $37.8mg{\cdot}100g^{-1}$ to $164.1mg{\cdot}100g^{-1}$, and the contents of free sugars were from 9.3% to 18.2%, and the contents of organic acids were from 8.1% to 14.7% in Korean hot peppers. Although the pungent sensory evaluation of water extract of pepper powder was completely accordant with instrumental analysis result of capsaicinoid contents, they did not show a significant relationship to the sensory of taste. Multiple regression with capsaicinoid (CAP), total sugars (TS) and total organic acid (TOA) contents increased the correlation coefficient for sensory of taste to r = 0.927 and the coefficient of determination for them to $R^2=0.906$. However, we suggest the more efficient function for it which is composed of two independent variables only. As the result, a regression equation of Y = 0.69 X + 0.11 with $R^2=0.884$ was obtained for quantitative analysis of sensory evaluation of pepper taste by two factors between capsaicinoid and total free sugar.

• Journal of the Korean Chemical Society
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• v.39 no.4
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• pp.257-265
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• 1995

Free amino acids were isolated from milk and their absolute amounts were determined by reversed phase high performance liquid chromatography after derivatization with dansyl chloride. The determination of D- and L-amino acids was based on achiral separation on a C18 column. It was found that milk contained totally 41.00 mg DL-amino acids in 100 mL milk. The level of D-amino acids to L-amino acids was determined by a column-switching system combining an achiral reversed phase separation and chiral chelate additive. The chiral separation was carried out with addition of the chiral Cu(N-benzyl-L-proline)2 chelate to the mobile phase in reversed phase liquid chromatography. It was found that the determination of 16 different amino acids is feasible in the milk sample with a C18 column separation and 12 D-amino acids out of the 16 amino acids can be determined via the column-switching system with chiral separation. 2.05% of D-glutamic acid and 2.93% of D-alanine were found in milk.

• Journal of Mushroom
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• v.12 no.4
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• pp.341-349
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• 2014

The composition and content of amino acid and free amino acid were separately compared in cap and stipe of fruitbody obtained from different color strains in winter mushroom and oyster mushroom strains. The result showed different kinds and amount of amino acids according to the mushroom parts, strains and kinds. Tryptophane was not detected in any mushrooms. Alanine was also not detected in all oyster mushroom strains. The content of glutamic acid was the highest and that of methionine, phenylalanine and cysteine were very low in all mushroom strains. When compared by parts, the ratio of amono acids showed similar tendency in composition. Generally the content of amono acids showed higher in caps than in stipes. The profile and content of free amino acid showed a lot of variation between cap and strip in the intra and inter mushrooms.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.701-708
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• 1996

To evaluate the possibility of using a by-products of skipjack canning as a food or feedstuff, the proximate composition, total and free amino acids, total lipid composition, and nucleotide related compounds were analyzed. The crude protein was highest in dark muscle, while lipid was highest in head. The important total amino acids in by-products were founded to be glycine, glutamic acid, alanine and histidine. The important free amino acids from dark muscle and head were taurine, histidine and anserine. The amounts of histidine, anserine and carnosine in dark muscle was higher than those of cooking drips, head, and raw vicera. The major fatty acids in by-products were palmitic, stearic, oleic and docosahexaenoic acid (DHA). The inosine and hypoxanthine were important nucleotide related compounds in by-products. The results suggests that by-products from skipjack can be used as food sources and feedstuffs especially for marine fish culture.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.2
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• pp.214-220
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• 2008

The purpose of this study was to investigate the quality characteristics of domestic and imported slices of skates Raja kenojei. Four types of slices of skates Raja kenojei were analyzed for proximate composition, extractive nitrogen, free amino acids, and fatty acids. A large amount of TMAO was detected in the domestic slices of skate. Both the domestic and imported skate contained aerobic bacteria, with approximate levels of 6.6 log CFU/g and 5.1${\sim}$6.5 log CFU/g, respectively. The total free amino acids contents of the domestic and imported skates were 579.7 mg and 387.6${\sim}$496.3 mg, respectively; all samples had high levels of taurine, anserine, lysine, alanine, glycine, proline, ${\beta}$-alanine, and histidine. Eleven different saturated fatty acids were found in the domestic skates whereas the impored skate had 7${\beta}$10 different types of saturated fatty acid. In addition, 16 kinds of domestic skate, and 10${\beta}$15 kinds of imported skate were analyzed for unsaturated fatty acid content. From the overall results, the domestic skate proved to be a better source of amino acid, and had higher levels of aerobic bacteria and fatty acids than the imported skate.

• Journal of the Korean Society of Food Culture
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• v.2 no.1
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• pp.25-31
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• 1987

We have examined to evaluate the taste compounds of damchi-jeotguk(concentrated sea mussel extract) which is a kind of traditional processed sea food in Korea. The contents of such compounds as free amino acids, nucleotides their and related compounds, non-volatile organic acid and fatty acid composition were analyzed. The content of total free amino acids was 10520.5mg/100g on dry basis and the major ones were glycine, arginine, aspartic acid and glutamic acid. These amino acids were resulted as 55.7% of total free amino acids in damchi-jeotguk. Hypoxanthine was the highest content($8.77\;{\mu}mole/g$, dry basis) of nucleotides and their related compounds. Free amino acid-N was the most abundant, resulting 53.3% of extractive nitrogen which was 3490.2mg/100g on dry basis and next ammonia-N, nucleotide-N and TMAO-N in order. The major non-volatile organic in damchi-jeotguk were succinic acid(125.5mg/100g, dry basis) and lactic acid 91.9mg/100g, dry basis). In this fatty acid composition of total lipid, polyenoic acid was abundant holding 45.5%. The major fatty acids were 16 : 0, 18 : 2, 22 : 6, 18 : 1 and 20 : 5. It was concluded from the omission test and chemical analysis that the major taste compounds of damchi-jeotguk were free amino acids and non-volatile organic acids.

• Proceedings of the Korean Vacuum Society Conference
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• 2009.02a
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• pp.191.2-191.2
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• 2009

• Proceedings of the Korean Society of Crop Science Conference
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• 2007.11a
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• pp.259.2-259.2
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• 2007

• The Microorganisms and Industry
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• v.20 no.1
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• pp.38-41
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• 1994

아미노산은 발효법, 합성법, 효소법, 추출법 등으로 제조되고 있으며, 아미노산 시장의 대부분을 차지하는 glutamic acid, lysine, methionine, glycine, phenylalanine등의 주요 아미노산은 전통적인 발효법과 합성법에 의해 주로 제조되고 있다(1-3). 표 1에 주요 아미노산의 생산량, 제조법, 용도들을 표시하였다. 최근 고정화효소법 및 화학합성법과 효소법을 병행한 반합성법(hybrid process 또는 chemico-enzymatic process라고도 함) 등의 새로운 아미노산 제조법(3-7)이 개발되어 주목되고 있다. 이러한 새로운 아미노산 제조법은 효소를 촉매라는 시각에서 수행하고 있기 때문에 생물촉매법이라 총칭하며, 생물촉매법은 화학반응으로는 곤란한 반응을 효소반응의 도입에 의하여 효율적으로 수행할 수 있는 특징과 각종 연관 아미노산 화합물을 동시에 제조할 수 있다는 대단히 유리한 장점 때문에 새로운 아미노산 제조법으로 점차 기업화되고 잇는 추세이다. 따라서, 본고에서는 생물촉매를 이용한 아미노산의 새로운 제조법에 대하여 소개하고자 한다.