• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.48-53
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• 1995

Changes in the contents of sugar, organic acid, free amino acid and uncleic acid-related compounds of leaf mustard-Kimchi during fermentation at 5~7$^{\circ}C$ were investigated. The leaf mustard-Kimchi was formulated with 4kg leaf mustard, 120g garlic, 80g ginger, 540ml salted anchovies, 1kg green onion, 200g red pepper powder, 200g ground red pepper, 60g whole sesame and 600ml glutinous rice paste. Changes in pH and acidity were relatively slow. Major free sugars were glucose(0.13%) and maltose(0.42%), and residual sugars(0.03-0.04%) were also detected after 32 days of fermentation. Major free amino acids containing more than 26.5mg% were proline, glutamic acid, alanine and histidine. Contents of total free amino acids increased from 244.8 to 397.2mg% by 24 days of fermentation. Of non-volatile organic acid, lactic acid was the most abundant(119.3mg%), and its content increased markedly after 10 days of fermentation. Other organic acids(below 53.1mg%) observed were malic, oxalic and citric acid. Contents of nucleic acid-related compounds were high in the order of hypoxanthine(22.8mg%), IMP(8.3mg%) and GMP(6.9mg%). Hypoxanthine content increased by 10 days(27.3mg%) and decreased thereafter, while the others decreased gradually during the overall period of fermentation.

• Applied Biological Chemistry
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• v.23 no.2
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• pp.89-105
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• 1980

Soysauce was made in the salt concentrations of 22.0% and 28.5%, and the changing aspects in nucleotides and their related compounds, free amino acids, free sugars and non-volatile amines which are related to the taste components during the fermentation process with a view to examining the taste components in the ordinary Korean soysauce were studied. And then artificial soysauce was prepared by applying the values derived from the analysis and measurement, and its sensory evaluation was performed. As the result of the sensory evaluation of artificial soysauce prepared according to the value of components analyzed from soysauce which had been fermented for fourty days in the salt concentration of 22.0%, it has been found that artificial soysauce was similar in taste to ordinary Korean soysauce. So, the following facts have been found: glutamic acid and aspartic acid have MSG-like taste, and IMP has a synergistic effect with these acids, which play great roles in ordinary Korean soysauce; both free sugars such as galactose and amino acids such as glycine, alanine and lysine have sweet taste; both amines such as tyramine and histamine, and amino acids such as valine, leucine, isoleucine, and phenylalanine have bitter taste; these components, combined with saline taste of salt and sour taste of organic acids, are assumed to form the unique taste in the ordinary Korean soysauce.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.76-81
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• 1990

For the determination of principal taste components in L. chinensis M., A. acutiloba K., S. chinensis B. and A. sessiliflorum S., which were extracted with water and ethanol, contents and composition of free sugars, free amino acids, non-volatile organic acids and tannins were analyzed. The extraction yield of them was high when using the water as an extraction solvent, the optimal ethanol concentration with high yield was in the range of 50-75%. The contents of free amino acids in their extract $(25^{\circ}Bx)$ was high when using the ethanol as the extraction solvent. The amino acid content was in the range of 123-159 mg%. in samples. The free sugar of extracts contained 2-12% in samples which were consisted of glucose, fructose and sucrose. The pH and acidity range of extracts were 4.4-5.1 and 1.01-2.27% respectively, and especially extracts of S. chinensis B. showed to be strong acid as pH 2.9 and addity 11.93%. The composition of non-volatile organic acid in extracts of S. chinensis B. contained citric acid and malic acid 3.90% and 3.92% respectively as major components. The tannin content of extracts was considerably high when extracting with 50% ethanol, especially A. sessiliflorm S. contained $3.35%{\sim}3.85%$.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.980-985
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• 1994

We investigated the quality of soybean paste(Doenjang) fermented by BAcillus brevis. The results obtained were as follows : soybean paste fermented by Bacillus brevis had alkaline pH and yellow ochre color. Dextrinizing activity was about 98 D.P. unit from 5th to 25th day of fermentation at 3$0^{\circ}C$ and after that day somewhat decreased . Saccharifying activity was respectively 6.1, 7.2, 6.8, 6.4 S.P. unit on 5, 15, 25 and 35th day of fermentation. Protease activity suddenly increased after 15th day of fermentation and was 250, 275, 299 unit on15, 25, 35 th day of fermentation , respectively. The most abundant free amino acid was found to be glutamic acid (561.8mg%) in soybean paste fermented by Bacillus brevis. In case of free sugar and non-volatile organic acid, fructose and oxalic acid showed highest content of 10.25mg% on 25th day and 12.20mg% on 15th day. The contents of free amino acids, free sugars, organic acids in soybean paste fermented by B.brevis were most abundant after 25 days of fermentation and this results were similar to that of traditional soybean paste. The odor of soybean paste fermented by Bacillus brevis was improved to be a nice soybean paste odor on 25th day of fermentation. However, sensory evaluation value of the taste of it decreased after 10 th day of fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.68-75
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• 2000

Optimum processing conditions for vinegar fermentation using fig, pear and persimmon were determined. Alcohol contents in the fermentatio broth of crushed fruits of fig, pear and persimmon were 7.5%, 5.1% and 6.8%, respectively. Alcohol contents increased up to 14.3~15.1% by adding 24% of sugar to the fruit juices. The total acidity of 7.04%, 3.30% and 3.66% were obtained for fig, pear and persimmon, respectively, through acetic acid fermentation of fruit juices containing 8% ethanol. Acetic acid yield increased by shaking during fermentation for pear and persimmon broth. Acetic acid yield increased 1.80~1.92 times by adding 0.5% of yeast extract to the fermentation broth of pear and persimmon. After fermentation, each fruit vinegar was clarified up to 93.1~97.4 of light transmittance by using 0.6% of kaki shibu for 4 days at 1$0^{\circ}C$. After aging for 60 days at 1$0^{\circ}C$, the acidity of fruit vinegar decreased slightly. Tannin content of persimmon vineger was remarkably higher than the other, while light absorbance of pear vinegar was higher than the other vinegars. Acetic acid was identified as the main volatile organic acid in the fruit vinegars, while propionic, isobutyric and isovaleric acids were identified as the minors. The content of non-volatile organic acids in the pear vinegar was higher than that in the persimmon vinegar. Sensory evaluation results indicate that the fig vinegar was preferred to the pear vinegar in the aspects of color, flavor and overall acceptability, but the fig vinegar had a strong background taste. Sensory scores of the persimmon vinegar increased significantly by pasteurization, but those of the fig and pear vinegars did not by pasteurization.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.227-233
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• 1986

The compositions and seasonal variations of free sugars and non-volatile organic acids of brown algae, such as Ecklonia cava, Sargassum ringgoldianum and Myagropsis myagroides were investigated by gas chromatography. Four kinds of free sugars, such as xylose, glucose, galactose and floridoside were identified. The most abundant one was floridoside marking 118.7 mg/100 g, 90.9 mg/100 g and 70.0 mg/100 g in Ecklonia cava, Sargassum ringgoldianum and Myagropsis myagroides, respectively. There were not distinguishable seasonal variations in the contents of free sugars in all the samples. In the case of organic acids, nine kinds were identified in Ecklenia cava and major ones were succinic, citric, malic, fumaric, oxalic and lactic acid, of which succinic acid was the most abundant one marking $30.6\%$ of total organic acids. In Sargassum ringgoldianum and Myagropsis myagroides, eight kinds were identified, which major ones were succinic, citric and malic acid in both samples, and they marked $68.4\%$ and $61.1\%$ of total organic acids in Sargassum ringgoldianum and Myagropsis myagroides, respectively. There were not distinct changes in the content of total organic acids according to seasons in all the samples examined. The contents of total organic acics in Ecklonia cava was a little more than Sargassnm ringgoldianum and Myagropsis myagroides.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.107-112
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• 2001

The various components of sigumjang were analyzed according to fermentation time. Aerobic bacteria were increased with fermentation time. Yeasts and molds were increased until 3 days after fermentation and then not changed. Six free sugars, 3 volatile organic acids and 6 non-volatile organic acids were detected. The content of free amino acids was $1,407.9{\sim}3,053.9\;mg%$. Glutamic acid was most abundant component among the amino acids, followed by phenylalanine, arginine and valine. The ratio of essential amino acid was $34.4{\sim}37.0\;mg%$. The content of mineral was $12,966.7{\sim}13,864.5\;mg%$. Potassium was the most abundant in quantity among the minerals in sigumjang except sodium which was added artificially. The principal fatty acids were linoleic acid, palmitic acid and oleic acid. The ratio of unsaturated fatty acids was $76.3{\pm}1.1%$. As a result of sensory evaluation, the highest score was obtained 3 to 5 days after fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.639-646
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• 1997

The contents of free sugars, organic acids, amino acids, total carotenoids and pectin of pumpkin were analysed. Weight percentage of flesh was 84% of total weight. Rind and funicular attachment of seed were 10% and 3.5%, respectively. Major free sugars in pumpkin were fructose, glucose, sucrose. In flesh, fructose and glucose were the major free sugars, corresponding to 87% of total free sugars . Total sugar content in the flesh was three times higher than that in the funicular attachment of seed. Contents and composition of free amino acids were quite different according to the different parts of pumpkin. Non-volatile organic acids in pumpkin was malic, succinic and fumaric acid. The major acid in the flesh and funicular attachment of seed was malic acid and the contents in these parts were 85.2mg% and 226.5mg%, corresponding to 63% and 70% of the total organic acids, respectively. Eigh-tyseven percent of total carotenoids in the pumpkin was in the funicular attachment of seed, amounting 65.3mg%. However flesh and rind contained 6.6mg% and 3.3mg%, respectively. Water soluble pectin consisted 58% of the total soluble pectin in different parts of pumpkin, and soluble Pectin content was higher in funicular attachment of seed than in flesh. The major neutral sugars of the pectin in flesh and funicular attachment of seed were galactose and glucose consisting 45% and 36.5% of total neutral sugars.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.274-279
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• 1995

Seasonal variation of the taste components such as free amino acids, nucleotides, quarternary ammonium bases, and guanidino compounds in warty sea squirt(S. clava) were determined bimonthly from April to October for its food quality contributed in Korean seafood dishes. Fifty to sixty two percentage of the extractable nitrogen was free amino acids, and mainely it composed of taurine, proline, glutamic acid, glycine and glycinebetaine. Among the various taste component, betaine's level was somewhat higher(11~15%) and nucleotides related compounds also followed(5~8%). Most of nitrogenous compounds in the extractives reached to a maximum value in June and AMP content was relatively higher than the other nucleotides. The major organic acids were composed of succinic acid, malic acid, lactic acid and pyroglutaric acid in S. clava. The result of omission test suggested that the taste of S. clava is mainly attributed to free amino acids, betaines, nucleotides and non-volatile organic acid in order.