• Preventive Nutrition and Food Science
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• v.14 no.2
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• pp.156-161
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• 2009

Effects of extrusion conditions (barrel temperature and moisture content) and fermentation time on the antioxidant properties of root hair of tissue cultured raw mountain ginseng (MG) were investigated. The barrel temperature/ moisture combinations were: $110^{\circ}C$/25% (MG1), $140^{\circ}C$/25% (MG2), $110^{\circ}C$/35% (MG3) and $140^{\circ}C$/35% (MG4). Red ginseng (RG) was also investigated. The contents of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and polyphenolic increased after fermentation in RG and even more in MG, while extruded ginseng samples exhibited little change. The increases noted with MG and RG occurred during the first 4 days of fermentation. DPPH radical scavenging activity decreased after extrusion and was significantly higher in MG (20.93%) than RG (1.63%) on the first day of fermentation. DPPH radical scavenging activity in the barrel temperature/moisture combinations were 19.01% (MG1), 14.45% (MG2), 20.37% (MG3) and 15.78% (MG4). The content of polyphenolic compounds in ginseng samples displayed a similar trend. Acidic polysaccharide in RG and MG1${\sim}$MG4 were higher than MG, but decreased during fermentation. Crude saponin in RG and MG1${\sim}$MG4 decreased after 15 days of fermentation, while increasing in MG.

• Korean Journal of Food Science and Technology
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• v.23 no.6
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• pp.739-744
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• 1991

A palatable paste-type lactic fermented rice (LFR) was prepared by lactic acid fermentation after liquefaction and saccharification of cooked rice. A mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus (1 : 1) produced the LFR of the best quality. A great improvement in quality of the LFR was achieved by 0.02% each ${\alpha}-amylase$ and glucoamylase treatment during the fermentation (simultaneous saccharification and fermentation), which resulted from the increased sourness and sweetness and the decreased size of solid particles contained in the LFR. The resulted LFR was superior in quality. Physical and chemical properties of the LFR were evaluated.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.603-610
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• 2011

This study was performed to examine the physicochemical characteristics and sensory properties of makgeolli with dried citron peel and levels (3, 6, and 9%) of citron (Citrus junos) in makgeolli during fermentation with two-step-brewing. The pH of makgeolli with citron dried peel increased within 5 days of fermentation, and decreased until 11 days of fermentation. Total acidity increased after 3 days of fermentation then decreased after 5 days of fermentation, but continued to increase slightly up to 12 days. Changes in alcohol content and amino acidity increased during fermentation. A sensoryevaluation of appearance, flavor, sourness, sweetness, bitterness, and overall acceptance of makgeolli with citron dried peel showed lower values than those of the control.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.744-751
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• 2013

The objective of this study was to assess the physicochemical and sensory changes of a kefir manufactured by a two-step fermentation (MTY, $1^{st}$ step: $37^{\circ}C$ for 9 h; $2^{nd}$ step: $24^{\circ}C$ for 15 h) and compare it with kefirs produced by two conventional methods (GTY, fermentation at $37^{\circ}C$ for 24 h; KEY, $22^{\circ}C$ for 24 h). Rapid changes in pH and titratable acidity (TA) were observed in samples from all three manufacturing methods during fermentation process and storage period. Lactic acid bacteria (LAB) counts of MTY increased gradually up to 12 h of fermentation, reaching 9.28 Log CFU/mL, with maximum value observed in this experiment of 9.48 Log CFU/mL. The LAB counts of all samples decreased significantly during storage. The highest viscosity was observed for MTY (1750-1771 cPs), compared with the lowest viscosity observed for KEY (1250-1277 cPs). The viscosity of all samples increased slightly during storage (1250-1805 cPs, p<0.05), as well as carbon dioxide content (0.01-1.36%, p<0.05), except for GTY. The most significant increase in alcohol concentration during storage period was seen in MTY from 0.01% to 1.36% (p<0.05). MTY scored significantly higher in most items of the sensory analysis, indicating that the product manufactured by the two-step fermentation method is more acceptable compared with conventionally produced kefirs.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.431-437
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• 2015

In this study, high-acidity cider vinegar (HACV) was produced by alcoholic and acetic acid fermentation of apple concentrate without any nutrients and then the optimum alcohol concentration was determined through a qualitative study. HACV was fermented with different initial alcohol concentrations (6-9%) during the process of acetic acid fermentation. The highest content of reducing sugar, organic acids, and free amino acids was observed at 6% of initial alcohol concentration. Approximately 20 types of volatile compounds were identified by solid-phase microextraction (SPME) and GC-MS. The total volatile content was the highest at 6% of initial alcohol concentration, and the acid content was the lowest at 9% of the initial alcohol concentration. The HACV produced by a two-stage fermentation process was qualitatively better than commercial HACV presenting the highest value at 6% of initial alcohol concentration. Malic acid, aspartic acid, and hexyl acetate were selected as quality index components of HACV production by two-stage fermentation on the basis of correlation between their physicochemical properties and the sensory attributes of HACV.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.466-475
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• 2016

Purpose: This study investigated the quality characteristics and antioxidant effects of Yakju added with rose, camellia, or cockscomb flower during fermentation. Methods: The quality characteristics and antioxidant effects were estimated including pH, amino acidity, total acid, ethanol content, color value, sensory test, electric donating ability, nitrite-scavenging ability, and ferrous ion chelating effect. Results: The pH values of Yakjus added with rose, camellia, or cockscomb flower were decreased after 2 days of fermentation and then increased after 4 days of fermentation, with final pH ranging from 4.15 to 4.27. Total acid content and amino acidity were increased during fermentation. The ethanol content in Yakjus fermented with rose, camellia, or cockscomb flower was rapidly increased after 2 days of fermentation, reaching the maximum content of 19.1% after 8 days of fermentation. In color evaluation, the L values of Yakjus added with rose, camellia, or cockscomb flower did not changes during fermentation, whereas values of a and b were increased. Total phenolic compound contents in Yakjus added with rose, camellia, or cockscomb flower were 0.67, 0.59, and 0.52 mg/mL, respectively. Total flavonoid contents in Yakjus added with rose, camellia, or cockscomb flower were 0.20, 0.09, and 0.26 mg/mL, respectively. In sensory test, the overall acceptability of Yakjus added with cockscomb flower was higher than that of Yakju added with rose or camellia flower. However, the difference was not statistically significant (p<0.05). Electron donating ability and nitrite-scavenging abilities were the highest in Yakjus added with rose flower, whereas ferrous ion chelating effect was the highest in Yakjus added with cockscomb flower. Conclusion: These results indicated that Yakjus added with rose, camellia, or cockscomb flower might have valuable functional properties due to their antioxidant effects.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.2
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• pp.104-110
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• 2011

This study was conducted to improve the food functional and sensory food quality of Hizikia fusiforme by the fermentation of lactic acid bacteria. Seven strains of lactic acid bacteria isolated from traditional Korean fermented food were inoculated and cultivated in H. fusiforme water extract. Among them, Lactobacillus brevis LB-20, isolated from Kimchi, was selected for further study by considering the results of bacterial growth, DPPH radical scavenging activity, and sensory evaluation. No significant differences in proximate compositions (moisture, crude protein, crude fat, and crude ash) were observed by the fermentation of L. brevis LB-20. The most dramatical change was the conversion from glutamate to ${\gamma}$-aminobutyric acid (GABA) in H. fusiforme water extract fermented by L. brevis LB-20. The GABA content increased approximately 60-fold after 48 hr of fermentation. The bacterial fermentation also resulted in low-molecularization of the extract. The particle size of the fermented extract became approximately 4-fold smaller than that of the law extract. In addition, the analysis of volatile flavor compounds using GC/MS revealed that the bacterial fermentation dramatically removed off-flavors such as acetaldehyde, haxanal, diallyl disulphide and 1-penten-2-ol in the H. fusiforme extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.330-335
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• 1995

The purpose of this study was to investigate the effects of onion on the physicochemical, microbiological and sensory properties of Dongchimi. Dongchimi with levels(0, 5, 10, 20%) of onion was fermented at twodifferent temperatures : Group A was fermented at 4$^{\circ}C$ and group B was fermented at 4$^{\circ}C$ after fermentation at room temperature(27$\pm$0.5$^{\circ}C$) for 24 hours. During the fermentation up to 45 days, total acidity increased while pH decreased gradually. Total acidity of group B was relatively higher than that of group A. The content of reducing sugar was reached the maximum value in 6 days of fermentation in the group A and on 3 days in the group B. Especially, the highest content of reducing sugar was shown on the Dongchimi added with 5% onion in the group A and 20% onion in the group B. Vitamin C was reduced in the early stage of fermentation, and increased gradually after 10 days. However, vitamin C of Dongchimi without onion increased rapidly in the early stage of fermentation and remarkably decreased thereafter. After 20 days, vitamin C was maintained in Dongchimi added with 10% onion of both two groups. The number of lactic acid bacteria was reached the maximum value on 1 day in the Dongchimi without onion and on 3 days in the Dongchimi added 5, 10 and 20% onion of group A, while gropu B was reached on 1 days and then decreased thereafter. As a result of the sensory evaluation, Dongchimi added 5% onion in the group A showed the highest scores in texture and overall acceptability. Whereas, in the group B, Dongchimi added 20% onion was the most preferable one.

• Korean journal of food and cookery science
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• v.19 no.4
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• pp.504-510
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• 2003

To optimize the preparation process of Jeung-Pyun, an experiment was derived, using a central composite design, to fmd the optimal mixing conditions. The addition of Paecilomyces japonica powder, the volume of Tak-Ju and the second fermentation time were independent variables, with the pH, volume, color, sensory and texture properties of the Jeung-Pyun selected as response variables. As the Paecilomyces japonica powder and fermentation time were increased, the b values and volume after the second fermentation also increased. The color of the Jeung-Pyun became deeper with increases in the Paecilomyces japonica powder and fermentation time, and was deepest on the addition of 30% Tak-Ju. The pH increased with increasing fermentation time of the Jeung-Pyun, and on the addition of 3% Paecilomyces japonica rapidly increased more than with the other groups. The optimal mixing conditions for the best quality Jeung-Pyun, with restricted conditions above a b value of 3, a color intensity above 3, and a volume of 40mQ and a pH of 4.02-4.04 after the second fermentation, were 4.0%, 20% and 45 mins for the Paecilomyces japonica powder, Tak-Ju and second fermentation time, respectively.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.23-29
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• 1996

This study was conducted to investigate the changes in chemical, microbial and sensory characteristics, and antimutagenicity of buchu(leek, Allium odorum) kimchi during fermentation at 15$^{\circ}C$. Reducing sugar contents and pH of buchu kimchi were decreased during the fermentation. The reduction rate of reducing sugar of glutinous rice paste and shrimp added buvhu kimchi(GSBK) was faster than those of control buchu kimchi(CBK) and glutious rice paste added bucku kimchi(GBK). Acidity increased rapidly until 4 days,a nd optimum acidity (0.6%) of bucku kimchi was reached within 2 day. Also total bacterial and lactic acid bacterial counts greatly increased after 4 days of the fermentation. The numbers of lactic acid bacteria after 8 day- fermentation in CBK and GSBK, and 10 day-fermentation in GBK were the highest values, 4.5$\times${TEX}$10^{8}${/TEX} CFU/ml, 4.8$\times${TEX}$10^{8}${/TEX} CFU/ml and 6.1$\times${TEX}$10^{8}${/TEX} CFU/ml, respectively. In the sensory evaluation, appearance of sample was good at 0 day, taste from overall quality of buchu kimchi were asquired the highest values at 6th day. The methanol extracts from buchu kimchi(GBK) showed antimutagenicity against aflatoxin {TEX}$B_{1}${/TEX}({TEX}$AFB_{1}${/TEX})in Salmonella typhimurium TA100. The inhibition ration were 58~69% with treatment of the 5% methanol extracts, and when the adding concentration increased the effect increased.