• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.136-138
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• 2002

In this work we describe the on-line monitoring technique for the analysis of fumaric acid in biotechnological processes. Fumarase and malate dehydrogenase(MDH) were immobilized on epoxy carrier and integrated into a FIA system. The effects of carrier buffer flow rate, pH, reaction temperature on the immobilized fumarase/MDH were investigated for the development of a fumarate-FIA system. Furthermore the effects of substrates, salts and metabolites dissolved in the sample on the activity of the immobilized enzyme were investigated.

• Journal of the Korean Home Economics Association
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• v.23 no.3
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• pp.75-84
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• 1985

This studies was conducted to elucidate the taste components of shellfishes, producted in Korea. Four kinds of shellfishes including sea mussel, short-necked clam, corb shell and ark ahell were selected according to the higher sales order and cheaper retail price at 50 fish markets in Seoul in August 1982. The results are : Palatable taste of shellfishes should be caused by nucleotide related products, organic acids and free amino acids. Thus taste components found in four shellfishes were succinic, fumaric, and lactic acids as organic acids, glycine, alanine and glutamic acid as free amino acids.

• Journal of the Korean Chemical Society
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• v.20 no.1
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• pp.43-47
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• 1976

The determination of oxalic acid is carried out with Zr(IV)-XO complex by spectrophotometry. The Mechanism of this method in 1∼4N HCl solution is shown below (XO = xylenol orange); Zr(IV)+XO=Zr(IV)-XO+ excess XO, Zr(IV) - XO + oxalate = Zr(IV)-oxalate + XO When oxalic acid is added to Zr(IV)-XO complex(red color), the absorbance of Zr(IV) - XO complex is decreased in proportional to the amount of oxalic acid. The malic, malonic, maleic, fumaric, succinic, folic and glutamic acid did not interfere even if they are present in hundred times of oxalic acid. If they are present in the same amount as oxalic acid, citric and tartaric acid did not interfere but they are interfere when they are present in much more than that of oxalic acid.

• The Korean Journal of Food And Nutrition
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• v.13 no.1
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• pp.71-77
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• 2000

New type yogurt base were prepared from milk added with skim milk powder or purple sweet potato, and fermented by lactic acid bacteria (Streptococcus thermophilus and Bifidobacterium infantis, 1:1, v/v). The yogurt proudcts were evaluated for acid production(pH, titratiable acidity), number of viable cell, viscosity, sensory properties, and color value. The composition of some organic acids was also analyzed by GC. The acid production slightly decrerased by addition with purple sweet potato. There was no significant difference in viable cell counts between control (yogurt added with only skim milk powder) and yogurt added with purple sweet potato, and viable cell counts of all samples were above 9.08 log cfu/ml. Viscosity of yogurt added with purple sweet potato(36,800∼46,000 centipoise) was higher than that of yogurt added with only skim milk powder(32,200 centipoise). The overall sensory score of yogurt added with purple sweet potato(38.6%, dry base) was the best of tested yogurt. The major organic acid of yogurt added with purple sweet potato was lactic acid. its content was 0.997∼1.203%. malic acid, succinic acid, oxalic acid, and fumaric acid were analyzed out a little. Lightness and yellowness decreased by addition with purple sweet potato but redness increased. Total color difference($\Delta$E) with yogurt addition with purple sweet potato and only skim milk powder were very high(above 11.46).

• Journal of Microbiology and Biotechnology
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• v.3 no.4
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• pp.266-269
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• 1993

The production of free non-volatile and volatile organic acids in Kimchi during fermentations at 30, 20 and $5^{\circ}C$, were determined by gas chromatography. The order in the amount of non-volatile organic acid, soon after preparation, was malic, citric, tartaric, pyroglutamic, oxalic, lactic, succinic and ${\alpha}-ketoglutaric$ acids. The major non-volatile acids at the optimum ripening time were malic, tartaric, citric and lactic acids, and as the temperature was lowered, the amount of lactic, succinic, oxalic, pyroglutamic and fumaric acids increased, while that of malic and tartaric acids decreased. The order in the amount of volatile acids at the beginning was acetic, butyric, propionic and formic acids. Among these acids, acetic acid was significantly increased in its amount during fermentation and the Kimchi fermented at low temperature produced more acetic acid than that fermented at high temperature.

• The Korean Journal of Mycology
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• v.11 no.1
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• pp.1-7
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• 1983

Nutritional characteristics and conditions for mycelial yield of Pleurotus ostreatus and Auricularia auricula-judae in shaking culture were investigated. Among the sugar substances, glucose and mannitol showed the good effect for mycelial yield of P. ostreatus, and mannitol and fructose were good for the mycelial yield of A. auricula-judae. Among the various organic acids, fumaric acid were good for the mycelial yield of P. ostreatus and A. auricula-judae. Among the nitrogen sources, peptone and urea showed the good result for mycelial yield of P. ostreatus, and peptone and casamino acid were good for mycelial yield of A. auricula-judae. Among the various amino acids, asparagin and threonine showed the good result for mycelial yield of P. ostreatus, and serine and threonine were good for mycelial yield of A. auricula-judae. Among the various vitamins, folic acid and thiamine were suitable for mycelial yield of P. ostreatus, and folic acid, inositol and riboflavin were suitable for mycelial yield of A. auricula-judae. Mycelial yield of P. ostreatus and A. auricula-judae were enhanced by the addition of $MgSO_4\;and\;KH_2PO_4$ at the concentration of 0.08 and 0.2% respectively. The optimum temperature and pH for mycelial yield were from $25\;to\;30^{\circ}C$ and pH 5.5 to 6.5 in P. ostreatus, and from $25\;to\;30^{\circ}C$ and pH 6.0 to 7.0 in A. auricula-judae.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.857-866
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• 2005

This study was carried out to evaluate changes in taste compounds of seasoned pork with Korean traditional sauces. The samples, pork loins were cut by the shape of cube($5{\time}15{\time}5$cm) and seasoned pork with Korean traditional sauces such as soy sauce base(T1), red pepper sauce base(T2), and soybean sauce base(T3) in the same proportion of meat seasonings, respectively. The seasoned samples were stored, at $1{\pm}1^{\circ}C$ during 28 days. Citric acid and fumaric acid were higher after 14 days of storage for the treatments, seasoned pork with red pepper sauce had higher compared to other treatments. While propionic acid and lactic acid were higher in seasoned pork with soybean sauce compared to other treatments. Free amino acids was higher in seasoned pork with soybean and red pepper sauce compared to seasoned pork with soy sauce. In all treatments, free amino acids was slightly increased with aging periods. 5'-inosine monophosphate(IMP) was decreased, whereas inosine was increased with increase of aging time. Inosine was higher in seasoned pork with soybean and red pepper sauce compared to seasoned pork with soy sauce. In sensory evaluation, aroma, flavor, tenderness and juiciness were increased with aging period increased in all treatments.

• Applied Biological Chemistry
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• v.49 no.4
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• pp.309-314
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• 2006

This study was performed to confirm the physicochemical properties and physiological activities according to cultivar and parts of Ulsan sweet persimmons. The proximate composition of the sweet persimmons was moisture $77.68{\sim}84.65%$, crude ash $0.3{\sim}0.6$, crude fat $0.29{\sim}0.39$ and crude protein $0.52{\sim}0.61%$. Confirmed organic acids and free sugars in sweet persimmons were malic, citric, succinic, and fumaric acids, along with fructose, glucose and sucrose. The major fatty acids were linolenic, vaccenic and palmitic acids. Also, K is the highest mineral in sweet persimmons that accounts for the majority of mineral, more than 60% as $84.9{\sim}103.7mg%$. Contents of vitamin C, total phenolic compounds and flavonoids were the highest in Fuyu peel as 139.91, 169.36 and 60.79mg%, respectively, Electron donating ability and xanthine oxidase inhibition were the highest in Fuyu peel as $30.6{\sim}91.2$ and $26.3{\sim}91.9mg%$, respectively. Nitrite scavenging activity was higher in peel than flesh as $51.0{\sim}76.4mg%$ with slight difference depending on cultivar.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.893-897
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• 2005

Effect of foliar application of stevia extract on strawberry quality was investigated. Soluble solid and free sugar contents of strawberry (SS) cultivated with foliar application of stevia extract were higher, and acidity and organic acid contents were lower than those of control. Free sugars were composed of fructose, glucose, and sucrose. Organic acids were composed of citric, malic, oxalic, succinic, and fumaric acids. Sensory evaluation revealed score of sweetness, sourness, and overall acceptability for SS were higher than those of control.

• 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.