• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.745-751
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• 1997

Volatile flavor components of kochujang made from a glutinuous rice by traditional method were analyzed by using purge and trap method during fermentation, and identified with GC-MSD. Fifty-one volatile components including 19 alcohols, 13 esters, 7 acids, 3 aldehydes, 1 alkanes, 2 ketones, 2 amines, 1 benzene, 1 alkene, 1 phenol and others were found in kochujang made by traditional method. The number of volatile components detected immediately after making kochujang were 22 and increased to 41 components after 30 day of fermentation. The most number 51 of volatile components were found after 120 day of fermentation. Twenty-two volatile components were commonly found through the fermentation period such as acetic acid ethyl ester, ethanol, butanoic acid ethyl ester, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol, butanoic acid and ethenone. Peak area(%) of 1-butanol was the highest one among the volatile components at immediately after mashing while ethanol showed the highest peak area after 30 day of fermentation. Although the various types of peak areas of volatile components were shown in kochujang during the fermentation days, acetic acid-ethyl ester, ethanol, butanoic acid-ethyl ester, 1-butanol, 3-methyl-1-butanol and 2-methyl-1-propanol were mainly detected during fermentation. Those might be the major volatile components in kochujang made by traditional method.

• Journal of the Korean Home Economics Association
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• v.23 no.4
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• pp.55-60
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• 1985

This study was carried out to compare the change of free amino acid content in the radish Kimchi added with anchovy pickle sauce with that added with 15% NaCl solution during 30 days fermentation. RESULTS : 1. During the fermentation, the pH of both sample A and B showed the highest values of 7.3 and 7.1, respectively, and then both decreased continually to the lowest value of 4.2 at the 30th day. 2.The salinity in the juice of sample A was higher than that of sample B in all the steps during fermentation, accompanied with a slight decrease of the salinity in both cases with time elapsed. 3. The free amino-type nitrogen content of sample A was nearly duplicated in the final step than in the initial one,while that of sample B showed no significant changes in all the processing period. 4. The free amino acids detected in the both samples were aspartic acid, threonine, serine, proline, glutamic acid, glycine, alanine, tyrosine, cysteine, valine, methinonine, isoleucine, leucine, phenylalanine, $\gamma-aminobutyrix acid(\ulcorner), ornithine, lysine, histidine and arginine. 5. The amounts of proline, arginine were the highest in all free amino acids during fermentation, and tasty components of radish Kimchi seemed to relate to glutamic acid, alanine, isoleucine, leucine, phenylalanine, more deliciousness of Kimchi A and B seemed to derive from amino acids of anchovy pickle sauce added to Kimci A, such as alanine, valine, phenylalanine, lysine.

• Korean journal of food and cookery science
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• v.10 no.1
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• pp.51-56
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• 1994

Conventional Doenjang, improved Doenjang prepared with Asp. oryzae were made to investigate the changes in the lipid content, and the carbonyl compounds during fermentation. Total lipid contents of conventional Doenjang increased slowly during fermentation, and that of the improved Doenjang increased at first, but showed sharp decrease at moment and then increased. Triglyceride contents of all samples decreased remarkedly during fermentation. Conversely, free acid contents increased. From the result of quantitative analysis of fatty acid by gas chromatography, saturated fatty acid ratio of total lipid in conventional Doenjang increased at early stages and then decreased, but unsaturated fatty acid ratio showed the reverse phenomenon. Saturated fatty acid in improved Doenjang increased during the fermentation but unsaturated fatty acid decreased by degrees. The concentration of total and monocarbonyl compounds in the fermented Doenjang were comparably higher than that found in raw Boenjang. Sensory evaluation revealed that off flavor had a negative effect on overall eating quality of Doenjang and total carbonyl content was related to the off flavor.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.691-694
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• 2007

Acetic acid and butyric acid were produced by the anaerobic fermentation of soil mixed with wheat or rice bran. The concentration of acetic acid produced in the wheat and rice bran-treated soil was 31.2mM and 8mM, respectively, whereas the concentration of butyric acid in the wheat and rice bran-treated soil was 25.0mM and 8mM, respectively. The minimal fungicidal concentration (MFC) for all the fungal strains was 40-60mM acetic acid, 20-40mM butyric acid, and 40-60mM mixture of acetic acid: butyric acid (1:1, v/v). Consequently, the efficacy of mixing wheat-bran with soil to control soil diseases was demonstrated.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1163-1169
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• 2004

An unstructured mathematical model is presented for lactic acid fermentation based on the energy balance. The proposed model reflects the energy metabolic state and then predicts the cell growth, lactic acid production, and glucose consumption rates by relating the above rates with the energy metabolic rate. Fermentation experiments were conducted under various initial lactic acid concentrations of 0, 30, 50, 70, and 90 g/l. Also, a genetic algorithm was used for further optimization of the model parameters and included the operations of coding, initialization, hybridization, mutation, decoding, fitness calculation, selection, and reproduction exerted on individuals (or chromosomes) in a population. The simulation results showed a good fit between the model prediction and the experimental data. The genetic algorithm proved to be useful for model parameter optimization, suggesting wider applications in the field of biological engineering.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.1-5
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• 2001

The potential use of spin filter device to retain Propionibacterium acidipropionici in the bioreactor under continuous mode of fermentation, and improve acid productivity, was examined. The yield of propionic acid based on lactose concentration was 51% in batch and 54% in continuous (dilution rate = 0.05 h(sup)-1) operation. The yield in continuous fermentation with cell retention using spin filter of 10 micron size (dilution rate = 0.05 h(sup)-1) was even higher at 70% (w/w). The volumetric productivity under batch and continuous mode of operation were 0.312g L(sup)-1 h(sup)-1 and 0.718g L(sup)-1 h(sup)-1 respectively. Continuous fermentation with cell retention demonstrated even higher volumetric productivities at 0.98g L(sup)-1 h(sup)-1 with out clogging problems. It could be used for utilization of cheese whey to produce propionic acid at higher yield and productivities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.53-60
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• 1999

Possibility of utilization of fig as a source of vinegar was tested. Alcohol fermentation was conducted by inoculation of Saccharomyces bayanus into fig juice. After 5 days of fermentation at 27oC, fig wine with alcohol content of 13.6%. Then fig vinegar was produced by cultivation of Acetobacter sp. E which was isolated from fig vinegar. Optimum concentration of alcohol, starter content and fermentation temperature for the acid production were 8~9%, 5% and 27~30oC, respectively. More acetic acid was produced by adding 0.5% of yeast extract and 0.01% of Ca pantothenate. Adjustment pH of culture broth with acetic acid and shaking cultivation method were not effective in higher yield of acid production. Addition of sulfite up to 50 ppm did not inhibit for acetic acid fermentation. Addition of 1% bentonite or 1% kakishibu was more effective for the clarification of fig vinegar than any other clarifying agents tested. During aging and racking, acidity, absorbance and tannin content of fig vinegar decreased, while redness and yellowness increased. Aged and racked fig vinegar showed higher sensory score than non aged one in the aspects of color and overall acceptability.

• KSBB Journal
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• v.7 no.1
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• pp.33-37
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• 1992

This study is to investigate the ethanol tolerance of yeast strains related to fatty acid composition and intracellular ethanol concentration for various fermentation temperatures. The maximum accumulation of ethanol in the cells was decreased by lowering the fermentation temperature, while unsaturated fatty acid content was increased by decreasing the fermentation temperature. Thus, we found that the increase of ethanol accumulation in cells resulted in the decrease of unsaturated fatty acid content. Therefore, it was suggested that the composition of unsaturated fatty acids in the cell membrane be strongly related to the diffusion of ethanol from cell to medium.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.304-308
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• 2007

This research was conducted to investigate the changes in quality characteristics of meju made with 24-hour germinated soybeans according to fermentation time. The study confirmed that the amino nitrogen content immediately after soaking was 15.5 mg%, and the content rapidly increased in the beginning of the germination process and continued to increase to 312.9 mg% by 48 hours of fermentation. The number of fungi in the whole soybean meju made with 24-hour germinated soybeans was higher than the numbers of bacteria and yeast since the Aspergillus oryzae was inoculated artificially. The content of organic acids, in which the amount of citric acid was highest followed by tartaric acid and malic acid, increased with the fermentation process. The level of free amino acids in the whole soybean meju made from the 24-hour germinated soybeans increased rapidly with fermentation. The free amino acid content after 48 hours of fermentation (2,513.5 mg%) was 5.7 times higher than the content of the soaked germinated soybeans. The content of glutamic acid was highest followed by aspartic acid, lysine, leucine, and proline. The ratio of glutamic acid to the total free amino acids at 48 hours fermentation was 21.2% for the whole soybean meju. It was confirmed that the total isoflavone content, in which the content of genistein was highest followed by daidzein and glycitein, increased at the beginning of the fermentation process, but did not change thereafter.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.167-172
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• 2001

The objective of this study is to investigate identification of lactic acid bacteria and changes of organic acid during aging of traditional Kyungsando Squid sikhe. Lactobacillus brevis SH-1, Lactobacillus plantarum SH-2, and Leuconostoc mensenteroides SH-3, which were isolated from Kyungsando Squid sikhe were selected for fermentation. The viable cell and lactic acid bacteria counts of squid sikhe was increased on fermentation days, and slowly decreased after 10 days of fermentation. The viable cell and lactic acid bacteria counts of standard sikhe at 6 days fermentation was $3.7{\times}10^9$ and $8.2{\times}10^8\;CFU/g$, respectively. The organic acid of squid sikhe consisted of 7 kinds including lactic acid during fermentation. The contents of citric acid, succinic acid, and lactic acid gradually increased during fermentation, and especially, increasing of lactic acid remarkably increased than the different organic acid. The contents of acetic acid and tartaric acid slowly increased after 7 days of fermentation.