• Journal of Biomedical Engineering Research
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• v.9 no.2
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• pp.225-232
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• 1988

Poly (L- lactic acid-co-glycine-L-lactic acid) and Poly (L-lactic acid-co-glycine-L- methyl lactic acid ) have been prepared by ring opening polymerization. The monomer 6, 6-dimethyl morpho-line-2, 5-dione was synthesized by the bromoisobutylation of 2-bromoisobutyryl bromide with glycin e. L-lactide, 6-methyl morpholine-2, 5-diode. and 6, 6-dimethyl morpholine-2, 5-diode have been used as starting materials for polydepsipeptides. The synthesized monomers and copolymers have been identified by NMR and FT-lR spa- ctrophotometer. The thermal propert ies and glass transition temperature(Tg) of the copolymers have been measured by differential scanning calorimetry. The Tg values of poly(L-lactic acid co-glycine-L-lactic acid) system are increased from $53^{\circ}C\; to\; 107^{\circ}C$ with increasing the mole fraction of 6-methyl morpholine-2, 5-diode. And the Tg values of poly(L-lactic acid co-glycine-L-methyl lactic acid) system are increased from $53^{\circ}C\;to\;138^{\circ}C$ with increasing the mole fraction of 6. 6-dimethyl morpholine-2, 5-diode The thermal stability of poly (L-lactic acid-co-glycine-L-methyl lactic acid) is slightly greta text than that of poly(L-lactic acid-co-glycine-L-lactic acid) due to the methyl group.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1190-1197
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• 2016

The acid response of Bifidobacterium longum subsp. longum BBMN68 has been studied in our previous study. The fab gene, which is supposed to be involved in membrane fatty acid biosynthesis, was demonstrated to be induced in acid response. In order to investigate the relationship between acid response and cell membrane fatty acid composition, the acid adaptation of BBMN68 was assessed and the membrane fatty acid composition at different adaptation conditions was identified. Indeed, the fatty acid composition was influenced by acid adaptation. Our results showed that the effective acid adaptations were accompanied with decrease in the unsaturated to saturated fatty acids ratio (UFA/SFA) and increase in cyclopropane fatty acid (CFA) content, which corresponded to previous studies. Moreover, both effective and non-effective acid adaptation conditions resulted in decrease in the C_18:1 cis-9/C_18:1 trans-9 ratio, indicating that the C_18:1 cis-9/C_18:1 trans-9 ratio is associated with acid tolerance response but not with acid adaptation response. Taken together, this study indicated that the UFA/SFA and CFA content of BBMN68 were involved in acid adaptation and the C_18:1 cis-9/C_18:1 trans-9 ratio was involved in acid tolerance response.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.2
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• pp.195-204
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• 1996

This study was conducted to enhance the shelf-life of Kimchi and to make the unique taste of Kimchi by fermentation control. Kimchis, Prepared by win baechu soaked in 10% salt solutions containing 0.2-0.3% organic acids (OS-Kimchi), acetic acid, citric acid (CA-Kimchi), lactic acid, its mixtures and formic acid+acetic acid+fumalic acid+malic acid+citric acid(FAFMC), were examined for pH, titratable acidify, sensory evaluation, the number of total microbe and lactic acid bacteria, content of organic acids and texture during fermentation at 1$0^{\circ}C$. The decrease of pH and the increase in acidity, CA-Kimchi showed lower than those of control and various OS-Kimchi. Total microbe, lactic acid bacteria, content of lactic acid of CA-Kimchi were lower than those of control. The hardness of CA-Kimchi measured instrumentally was higher than that of control. Sensory scores of CA-Kimchi were also lower than those of control, so the Kimchi maintained good crispness and overall taste.

• Preventive Nutrition and Food Science
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• v.20 no.1
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• pp.73-77
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• 2015

As an approach to search for chemopreventive agents, we tested p-coumaric acid, 3-methoxy-p-coumaric acid (ferulic acid), and 3,5-dimethoxy-p-coumaric acid (sinapic acid) in B16/F10 melanoma cells. Intracellular melanin contents were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and cytotoxicity of the compounds were examined by lactate dehydrogenase (LDH) release. p-Coumaric acid showed inhibitory effect on melanogenesis, but ferulic acid increased melanin content, and sinapic acid had almost no effect on melanogenesis. Treatment with ferulic acid resulted in a 2 to 3 fold elevation in the production of melanin. Correlatively, cell viability decreased in a dose-dependent manner when treated with ferulic acid. However, ferulic acid did not affect the LDH release from the cells. Treatment with sinapic acid resulted in a 50~60% elevation in the release of LDH when treated with a $200{\mu}g/mL$ concentration and showed neither cytostasis nor increase of melanin synthesis in a dose-dependent manner. Taken together, p-coumaric acid inhibits melanogenesis, ferulic acid induces melanogenesis, and sinapic acid exerts cytotoxic effects in B16/F10 murine melanoma cells. The results indicate that the addition of methoxy groups to p-coumaric acid shows the melanogenic or cytotoxic effects in melanoma cells compared to the original compound. Therefore, this study suggests the possibility that methoxylated p-coumaric acid, ferulic acid can be used as a chemopreventive agent.

• Food Science and Preservation
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• v.8 no.1
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• pp.60-65
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• 2001

To investigate the effect of Acetobacter on qualities of potato vinegars, potato vinegars were produced through acetic acid fermentation using 3 Acetobacters such as Acetobacter sp. PA97, Acetobacter sp. PA96 and Acetobacter pasterianus JK 99. There were little difference in pH(2.90∼3.09) and total acidities(5.30∼5.60%) of 3 potato vinegars. However potato vinegar(II) fermented by Acetobacter sp. PA96 showed a little difference in color values with other potato vinegars. Except acetic acid in each potato vinegars, the contents of citric acid, oxalic acid, succinic acid were high in potato vinegar(I), malic acid in potato vinegar(II) and lactic acid in potato vinegar(III). The contents of glutamic acid alanine, histidine and proline were high in all potato vinegars. The major volatile components in 3 potato vinegars were acetic acid, isoamyl acetate, isobutyl acetate, 3-methyl-1-butanol, 3-methyl-butanoic acid and phenethyl alcohol. Also composition ratio of volatile components was a little difference among 3 potato vinegars.

• Journal of Plant Biology
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• v.35 no.1
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• pp.25-36
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• 1992

The effects of amphotericin B ($150\;\mu\textrm{g}/ml$) and cycloheximide ($10\;\mu\textrm{g}/ml$) on the biosynthesis of phospholipid and the composition of fatty acids in chloroplasts isolated from ChZorella were analyzed. The contents of the total lipid and phospholipid (PC, PE, PI) in treatment with antibiotics were lower compared with the control. In the whole cell system, the major fatty acids utilized for biosynthesis of phospholipid were palmitic acid (31.96%) and linoleic acid (16.96%) in control while those were palmitic acid (36.15%) and linolenic acid (16.71%) in treatment with amphotericin B. And in treatment with cycloheximide, palmitic acid (31.90%) and stearic acid (15.32%) were used in phospholipid formation. The major fatty acids in chloroplasts were analyzed as to be palmitic acid and linolenic acid in control (33.75%, 18.90%) and in treatment with amphotericin B (36.75%, 9.46%). However, it was shown that the major fatty acids in chloroplasts treated with cycloheximide were palmitic acid (28.01%) and oleic acid (19.27%).9.27%).

• Applied Biological Chemistry
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• v.40 no.2
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• pp.123-127
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• 1997

To improve the quality and prolongation of chopped ginger, they were treated with NaCl, citric acid, ascorbic acid alone or combination of them at $5^{\circ}C$. The browning and stink of chopped ginger were prevented by adding 10% NaCl, $0.5{\sim}2.0%$ citric acid, but the control became severely browned and deteriorated after 1 month storage. The application of 0.5% citric acid maintained citrine color and decreased the activity of polyphenol oxidase(PPO) more significantly compared to 5.0% NaCl or 0.5% ascorbic acid. Ascorbic acid treatment become browned at $1.0{\sim}2.0%$ and easily deteriorated compared to citric acid. Citric acid(0.5%) or ascorbic acid (0.5%) treatment was largely variation of pH compared to NaCl(5.0%)+citric acid(0.5%) or NaCl(5.0%)+ascorbic acid(0.5%) treatment during 8 month storage. The activity of PPO in NaCl(5.0%)+ascorbic acid(0.5%) treatment was elevated after 4 month storage. In chopped ginger, NaCl(5.0%)+citric acid(0.5%)+ascorbic acid(0.25%) treatment was more effective than 5.0%+0.1%+0.1%, 5.0%+0.5%+0.1% during 12 month storage.

• Food Science and Preservation
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• v.7 no.3
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• pp.278-284
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• 2000

The chemical components in freeze dried Korean Gastrodia elata blume powder were analyzed. The proximate composition was composed of moisture(2.12%), crude protein (4.41%), crude fat(1.20%), crude ash(2.25%), crude fiber(4.60%) and N-free extract(85.15%). Free sugar was composed of glucose(1,314mg%), sucrose(1,081mg%) and fructose(869mg%). Total organic acid content was 2,095mg% and composed of succinic acid(1,238mg%), citric acid, malic acid, oxalic acid and fumaric acid in the order. Among the 11 fatty acids detected, linoleic acid was the most predominant one and unsaturated fatty acid was 80.55 area percent. 18 and 39 amino acids were detected from total and free amino acid, respectively. Arginine, asparagine, proline and sarcosine were the major components of free amino acid. The content of crude saponin and total phenol were 3,768mg% and 821mg%, respectively. Ascorbic acid(6.4mg%), vitamin B1(1.2mg%), vitamin B2(1.7mg%) and niacinamide(0.2m%) were detected as soluble vitamins of the powder. The content of vitamin A and vitamin E was 1.22mg% and 0.32%, respectively.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.898-904
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• 2002

The ehtyl acetate-soluble acidic fractions from juice and cake of Rubrs coreanum fruit showed DPPH radical-scavenging activity. Each fraction was purified through silica gel adsorption column chromatography. The compounds in the ethyl acetate-soluble acidic fraction of juice were identified as 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,4,5-trihydroxybenzoic acid, and 3,4-dihydroxycinnamic acid by GC-MS. The compounds in the ethyl acetate-soluble acidic fraction of cake were also identified as succinic acid, 3,4-dihydroxybenzoic acid, citric acid, 3,4,5,-trihydroxybenzoic acid, and 3,4-dihydroxycinnamic acid by GC-MS. Antioxidative activity of the identified compounds were evaluated by DPPH radical-scavenging assay and hydroxyl radical-scavenging activity assay.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.391-396
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• 2009

This study was carried out to investigate the changes in yeast cell number, organic acid and total acid during the fermentation and distribution processes for enhancement of preservation of Makgeolli. Organic acids, including lactic acid, succinic acid, malic acid and citric acid, were increased with fermentation time, while oxalic acid, phosphoric acid and acetic acid were not detected, respectively. Production of organic acids leaded to pH reduction in Makgeolli. In case of Makgeolli kept at $4^{\circ}C$, there was no change in organic acids until 20 days. On the other hand, when observing the change in organic acid of Makgeolli kept at $25^{\circ}C$, concentration of lactic acid was decreased, while citric acid was not detected from the beginning of storage. However, acetic acid was detected from 10th day and rapidly increased at the 25th day. Therefore, it is suggested that the current expiration date (10 days in a cooler) could be extended.