• Journal of the Korean Society of Food Culture
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• v.13 no.3
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• pp.191-196
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• 1998

The influence of organic acid dips on the quality properties, color, cooking quality, textural and sensory properties, and reducing microbial population of LL(Long Life) noodles was studied. The contents of organic acid used were 0.2% based on flour weight and LL noodles were treated by dipping in pH $2.5{\pm}0.1$ for $60{\sim}90sec$. The whiteness of LL noodles treated with dl-malic acid was higher than that of others. The shear extrusion force and hardness of LL noodles treated with dl-malic acid were shown much higher value than those of others except treated with dl-malic acid. acetic acid(=1:1). At cooking quality examination of LL noodles treated with organic acids, weight of cooked LL noodles treated with dl-malic acid was decrease but volume was appeared in vice versa. Extraction amounts of LL noodles treated with dl-malic acid, dl-malic acid : acetic acid(=1:1) during cooking were much smaller than those of others. Total counts of microorganism of LL noodles treated with dl-malic acid,dl-malic acid. acetic acid(=1:1) were disappeared during storage at $30^{\circ}C$ but treated with latic acid, acetic acid were increase during storage. Sensory properties of cooked LL noodles which was treated with dl-malic acid showed quite acceptable.

• Fibers and Polymers
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• v.1 no.2
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• pp.116-121
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• 2000

It has been considered that malic acid, $\alpha$-hydroky succinic acid, could not form crosslinks in the cellulosic materials unless activated by other polycarboxylic acids such as butanetetracarboxylic acid or citric acid because there are only two carboxylic acids per molecule available fur the formation of one anhydride intermediate. However we found that the dicarboxylic malic acid with sodium hypophosphite catalyst without the addition of other crosslinkers was able to improve wrinkle resistance of cotton up to $294^{\circ}$(dry WRA) and $285^{\circ}$ (wet WRA), which is a measure of crosslinking level in cotton. $^1$H FT-NMR, FT-IR and GPC analysis indicated the in-situ formation of an trimeric $\alpha$, $\beta$-rnalic acid with a composition of 1:3 through the esterification between hydroxyl group and one of carboxylic groups in malic acid during curing. The crosslinking of cotton was attributed to the trimeric $\alpha$, $\beta$-malic acid, a tetracarboxylic acid, which can form two anhydride rings during curing. The influence of crosslinking conditions such as concentrations of malic acid and catalyst, pH of the formulation bath, and curing temperature were investigated in terms of imparted wrinkle resistance and whiteness. The addition of reactive polyurethane resin in the formulation slightly increased the mechanical strength retention of crosslinked fabric coupled with additional increase in wrinkle resistance.

• Journal of Microbiology
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• v.45 no.6
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• pp.521-527
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• 2007

Several yeast strains degrading malic acid as a sole carbon and energy source were isolated from Korean wine pomace after enrichment culture in the presence of malic acid. Among them, the strain designated as KMBL 5774 showed the highest malic acid degrading ability. It was identified as Issatchenkia orientalis based on its morphological and physiological characteristics as well as the nucleotide sequences of the internal transcribed spacer (ITS) 1-5.8S rDNA-ITS II region. Phylogenetic analysis of the ITS I-5.8S rDNA-ITS II sequences showed that the KMBL 5774 is the closest to I. orientalis zhuan 192. Identity of the sequences of the KMBL 5774 was 99.5% with those of I. orientalis zhuan 192. The optimal pH of the media for the growth and malic acid degradation by the yeast was between 2.0 and 3.0, suggesting that the strain is an acidophile. Under the optimized conditions, the yeast could degrade 95.5% of the malic acid after 24 h of incubation at $30^{\circ}C$ in YNB media containing 2% malic acid as a sole carbon and energy source.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.263-271
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• 2011

This study was performed to develop duck stock using various nutritional elements in duck bone by the addition of malic acid (0.5%, 1.0%, 1.5% and 2.0%). Moisture contents, b value, and pH were decreased, while the L value, a value, salinity, and sugar contents were increased by increasing the ratio of malic acid. Thirty four types of free amino acid were detected, and the highest individual amino acid content was 1.0%. In a test for different attributes, malic acid content significantly affected properties including color intensity, transparency, acid flavor, savory flavor, acid taste, and savory taste. In the acceptance test, a malic content of 1.0% was preferred for appearance, taste, and overall quality. The optimal malic acid content for maximizing the overall quality of duck stock was 1.0%.

• Microbiology and Biotechnology Letters
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• v.9 no.3
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• pp.139-143
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• 1981

In order to investigate the changes of organic acid contents during the process of apple vinegar, this experiment was conducted by innoculating apple juice with Sarcharomyces cerevisae, and then the apple vinegar were prepared with Acetobacter. aceti and its mutants obtained by the treatment of ultraviolet light and N-methyl-N-nitro-N'-nitrosoguanidine. The organic acids were analyzed by gas chromatography. The contents of malic acid, citric acid and acetic acid in apple juice were 0.73 %, 0.038 % and 0.067%, malic acid, lactic acid and acetic acid in the apple wine 0.114%, 0.10%, and 0.03%, while acetic acid and malic acid in apple vinegar, 4.3 %, and about 0.05 %, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.4
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• pp.252-255
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• 2004

A pfl ldhA double mutant Escherichia coli strain NZN 111 was used to produce succinic acid by overexpressing the E. coli malic enzyme gene (sfcA). This strain, however, produced a large amount of malic acid as well as succinic acid. After the analyses of the metabolic pathways, the fumB gene encoding the anaerobic fumarase of E. coli was co-amplified to solve the problem of malic acid accumulation. A plasmid, pTrcMLFu, was constructed, which contains an artificial operon (sfcA-fumB) under the control of the inducible trc promoter. From the batch culture of recombinant E. coli NZN 111 harboring pTrcMLFu, 7 g/L of succinic acid was produced from 20 g/L of glucose, with no accumulation of malic acid. From the metabolic flux analysis the strain was found under reducing power limiting conditions by severe reorientation of metabolic fluxes.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.922-927
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• 2005

Total and individual organic acid contents of Malus domestica Borkh, cultivars, Tsugaru, Fuji Jonathan (Hong-Ok), and New Jonagold(Sin-Heung) apples, were investigated. Average titratable acidities measured by titration method and total organic acids content determined by HPLC were 241.64-444.52 and 364.23-680.80mg%, respectively. Average total organic acid contents were Jonathan 630.80mg%, New Jonagold 471.04mg%, Fuji 403.80mg%, and Tsugaru 364.23mg%, Contents of DL-malic, citric, fumaric, and quinic acid were 351.98 (Tsugaru)-579.88mg% (Jonathan), 2.14 (Fuji)-12.95mg% (Jonathan), 0.012 (Fuji)-0.060mg% (Jonathan), and 8.91 (Tsugaru)-14.20mg% (Fuji), respectively. Succinic acid was detected only from Jonathan (27.53mg%) and New Jonagold (5.20mg%), while maleic acid was not detected from all cultivars. Ratio of L-malic acid and DL-malic acid contents were 0.98-1.02 in all apple cultivars.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.4
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• pp.375-383
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• 2023

Malic acid-catalyzed transformation has been developed to produce ginsenoside Rg3 which is increasingly in demand as a functional ingredient. The optimization of the conversion of red ginseng saponin (RGS) to ginsenoside Rg3 by acid catalyzed transformation was carried out using Box-Behnken design (BBD) based on Response Surface Analysis (RSM). The main independent variables were malic acid concentration, temperature, and reaction time. Conversion of ginsenoside Rg3 was performed according to BBD model and optimization conditions were analyzed. The concentration of the converted ginsenoside Rg3 ranged from 1.548 mg/L to 4.558 mg/L, and the highest production was obtained under the condition of reacting 1% malic acid, 50 ℃ and 9h. Consequently, The independent variables affecting the production of ginsenoside Rg3 were identified in the following order: malic acid concentration, reaction time and temperature. In addition, it was confirmed that the interaction between malic acid concentration and reaction time had a greater influence than the temperature.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1440-1446
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• 1999

Fourty-two commercial vinegars were analyzed for their non-volatile organic acids, free sugars. amino acids, and volatile compounds. A study was made to characterize commercial vinegars chemically into three kinds of vinegars such as spirit, cider, and brown rice vinegars. Sixteen chemical components were significantly effective for the chemical characterization of commercial vinegars by stepwise discriminant analysis. Those were malic, succinic and lactic acids from the non-volatile organic acids; fructose and glucose from the free sugars; lysine, serine, leucine, valine and alanine from the amino acids; 1-hexanol, acetaldehyde, 3-methyl-1-butanol, 2-methylpropanoic acid, isopropyl butanoate and ethanol from the volatile compounds. Six components including malic acid, lysine, succinic acid, glucose, lactic acid and 1-hexanol were the most significant contributors to the differentiation of commercial vinegars into spirit, cider, and brown rice vinegars. In particular, cider vinegars could be characterized to be abundant in amounts of malic acid and 1-hexanol, whereas brown rice vinegars in amounts of lysine and lactic acid compared to spirit vinegars.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.35-41
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• 2006

Possible application of hurdle technology extention of shelf-life of fresh-cut apples was investigated by evaluating various hurdle factors known to be effective microbial growth inhibitors and their synergistic effects. Fresh-cut apples treated with chitooligosaccharide or grapefruit seed extract (GSE) showed higher microbial counts than those treated with distilled water during latter half of storage period, and at high concentrations. Citric and malic acids showed similar results, although microbial counts of fresh-cut apples treated with 0.75% or higher concentration of citric acid increased at 4 days of storage at $18^{\circ}C$, indicating malic acid is more effective than all hurdles tested for controlling microbial growth. Using ascorbic acid and calcium chloride as additional hurdles to control browning and softening, minimum and maximum compositions of dipping solution were: 0.25 : 0.5 : 0.25% and 0.75 : 1.0 : 0.75% malic acid: ascorbic acid: calcium chloride, respectively.