• Preventive Nutrition and Food Science
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• v.12 no.1
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• pp.46-50
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• 2007

Physicochemical properties of commercial long-term fermented kimchies which are widely available in Korea were investigated. The commercial long-term fermented kimchies were fermented almost more than 6 months. Average values for saltiness, pH and acidity of the long-term fermented kimchies were $3.0{\pm}0.5%$, $4.0{\pm}0.2$, and $1.88{\pm}0.76%$, respectively. The long-term fermented kimchi showed similar Leuconostoc sp. and Lactobacillus sp. counts as baechu kimchi ripened properly during fermentation. The amount of Leuconostoc sp. and Lactobacillus sp. of the long-term fermented kimchi were $10^{7\sim8}$ CFU/mL and $10^{4\sim7}$ CFU/mL, respectively. The long-term fermented kimchi showed $0.32{\pm}0.18$ lightness, $1.73{\pm}0.98$ redness, $0.52{\pm}0.31$ yellowness. Long-term fermented kimchi showed higher lightness, redness, yellowness than well-fermented standardized baechu kimchi. Breaking strength of long-term fermented kimchi was higher than that of well-fermented standard baechu kimchi.

• Journal of the Korean Society of Food Culture
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• v.16 no.5
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• pp.431-441
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• 2001

To develop the low-temperature and long-term fermented kimchi, kimchi was prepared according to the recipe of a specific ratio of major and minor ingredients and adjusted its salinity to 3.7%. Prepared kimchi fermented at $15{\pm}1^{\circ}C$ for 24 hours and transferred and fermented in a refrigerator only used to make low-temperature and long-term fermented kimchi at $-1{\pm}1^{\circ}C$ for 30 weeks. During 30 weeks of fermentation the changes in physicochemical and microbiological properties of low-temperature and long-term fermented kimchi were studied. The initial pH of 6.47 decrease gradually and dropped to pH 4.0 after 14 weeks of fermentation, and then it maintained at same level. Acidity increased to 0.49% on 2 weeks of fermentation and kept at 0.47 $\sim$0.50% during 2 to 30 weeks fermentation. Salinity was slightly increased at early stage and started to decrease on 4 weeks of fermentation, and then it did not change. The change of reducing sugar content was closely related to the trend of pH change with a very high correlation coefficient(r =0.912). Lactic acid, citric acid, malic acid, succinic acid and acetic acid were major organic acids contained in low-temperature and long-term fermented kimchi. Vitamin C content decreased at initial stage of fermentation and then slightly increased up to the maximum of 22.3 mg% on 8weeks of fermentation. In color measurement, L value continued to increase during the fermentation and reached at the highest of 55.45 on 22 weeks of fermentation, and a and b values of 3.62 and 4.54 also increased to 31.26 and 37.32 on 30 weeks of fermentation, respectively. Total microbial count increased slowly from beginning and was the highest on 4 weeks of fermentation, and then began to decrease slowly. Count of Lactobacillus spp. was highest after 6weeks, but count of Lactobacillus spp. was highest on 2 weeks of fermentation, and then both showed a slow decrease. Yeast count wasn't increased until 4 weeks of fermentation and then increased rapidly to get the highest on 10 weeks of fermentation.

• Food Science and Preservation
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• v.16 no.6
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• pp.804-809
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• 2009

Recently, many Koreans have started to consume aged kimchi fermented long-term at low temperatures. In the present study, the effect of low temperature ($5^{\circ}C$) on pH, titratable acidity (TA), organic acid level, viable microbial cell count, amino acid concentration, and polygalacturonase activity (PG) during long-term fermentation (46 weeks) of kimchi, were evaluated. After 10 weeks of fermentation, kimchi had a pH of 4.1 and a TA of 1.0%, respectively after 46 weeks fermentation, these values were 3.9 and 1.3%, respectively. Lactic acid, the ratio of lactic acid to acetic acid, and the ratio of Lactobacillus species/Leuconostoc species in kimchi increased as fermentation progressed from 10 weeks to 46 weeks. However, total viable cell counts of aerobic bacteria, yeasts, Lactobacillus species, and Leuconostoc species, free amino acid levels, and PG decreased as the fermentation period was extended from 10 weeks to 46 weeks.

• Journal of the Korean Society of Food Culture
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• v.21 no.3
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• pp.319-324
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• 2006

Volatile compounds in low-temperature and long-term fermented Baechu kimchi were extracted by high vacuum sublimation(HVS), and then analyzed by gas chromatography/mass spectrometry(GC-MS). A total of 62 compounds, including 7 sulfur-containing compounds, 8 terpenes, 5 esters, 8 acids, 15 alcohols, 2 nitrites, 2 ketones, 11 aliphatic hydrocarbons and 4 miscellaneous compounds, were found in low-temperature and long-term fermented Baechu kimchi. Among them, acetic acid and butanoic acid were quantitatively dominant. Aroma-active compounds were also determined by gas chromatography/olfactometry(GC-O) using aroma extract dilution analysis(AEDA). A total of 16 aroma-active compounds were detected by GC-O. Butanoic acid was the most potent aroma-active compound with the highest FD factor($Log_3FD$) followed by linalool, acetic acid, 2-vinyl-4H-1,3-dithin and 3-methyl-1-butanol. The major aroma-active compounds, such as acetic acid and butanoic acid, were related to sour and rancid or notes.

• Journal of the Korean Society of Food Culture
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• v.20 no.4
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• pp.426-432
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• 2005

To develop a low-temperature and long-term fermented Baechu kimchi, kimchi was prepared according to a recipe of specific ratio with major and minor ingredients and adjusted its final salinity to 3.7%. Baechu kimchi fermented at $15{\pm}1^{\circ}C$ 24 hours and transferred them into in a refrigerator only for kimchi, and then continued to ferment at $-1{\pm}1^{\circ}C$ for 30 weeks to make a low-temperature and long-term fermented kimchi. The initial cutting force of 8.45kgf dropped gradually and reached to 5.19kgf after 30 weeks of fermentation. In compression force the gumminess, hardness and chewiness of Baechu kimchi showed a great decrease during the fermentation, but the springiness and adhesiveness increased in slight. Correlation coefficient between the chewiness and gumminess was the highest(r=0.879). In spite of sensory evaluation scores of the appearance and texture were the highest on 0 day of fermentation, the saltiness was evaluated the worst to eat. Scores for sourness and carbonated flavor were the best during 18 to 22 weeks of fermentation, and overall acceptability was the best after 14 weeks of fermentation. Very high correlation coefficients were revealed between the sourness and carbonated flavor(r=0.813) and between the sourness and off-flavor(r=0.805). According to these results we concluded that the best low-temperature and long-term fermented Baechu kimchi prepared with 3.7% salinity and fermented at $15{\pm}1^{\circ}C$ for 24 hours and then transferred into a kimchi refrigerator at $-1{\pm}1^{\circ}C$, and completed the fermentation for 18 weeks.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.924-927
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• 2007

This study addresses the quality characteristics of commercial baechukimchi by analyzing its physicochemical characteristics and sensory properties in relation to fermentation time and temperature. The salinity of baechukimchi increased to 3.01% after 45 days of fermentation at 2 and $5^{\circ}C$, but decreased to 2.81% by 105 days. The pH decreased gradually at the beginning of fermentation, but decreased after 45 days. The acidity differed most between kimchi fermented at $2^{\circ}C$ (0.36%) and $5^{\circ}C$ (0.48%) at 45 days of fermentation. The vitamin C content was 8.47 mg% in kimchi fermented at both 2 and $5^{\circ}C$ on the day of initial production, then peaked after 45 to 60 days at 14.10 mg%, and decreased thereafter. The total microbial count gradually increased during the first 75 days of fermentation. The appearance and overall acceptability of baechukimchi were highest after 90 days of fermentation at $2^{\circ}C$ and after 60 days of fermentation at $5^{\circ}C$.

• Journal of the Korean Society of Food Culture
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• v.4 no.3
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• pp.265-269
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• 1989

Korean traditional fermented foods have been diversely developed to enhance taste and flavor while preserving them on a long term basis. For those furthur utilization and development, more efforts to commercialize these products focusing to the consumer's needs should be proceded. In that sence, the fermented foods might be classified into the bioproduct (biofood) and the sterilized. The former defines the non-sterilized such as Kimchi, Jeotkal (fermented fishes), and Jang (fermented soybean products) so as to include various kinds of microorganisms, enzymes and the unknown bioproducts, while the latter defines the sterilized such as soysauce and vinegars proper to the commercialization. In this paper, present R & D status has been reviewed laying stress on Kimchi, Jeotkal and Jang and the mixed fermentation system by the microflora was suggested as a Korean style model for the future R & D direction in these fields.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.89-90
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• 2001

Kimchi is a traditional fermented vegetable food in Korea. There are about 187 varieties of Kimchi, depending on the ingredients and processing methods used, which are different in microbiological, nutritional, and biochemical characteristics. Much attention for Kimchi has been focused on health and life extension. Kimchi is fermented by the microorganisms which are originally present in the raw vegetable substances.(omitted)

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.70-75
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• 2008

The Chinese cabbage kimchi, baechoo-kimchi, is the most popular type of kimchi in Korea. This study was performed to investigate the changes of index microorganisms (aerobic bacteria, psychrotrophilic bacteria, coliforms, and Escherichia coli), lactic acid bacteria, pH, and acidity of kimchi during the long-term fermentation and ripening. A homemade-style traditional Korean baechoo-kimchi, was prepared from Chinese cabbage, red pepper, green onion, garlic, ginger, and salt-fermented anchovy sauce, and then incubated at $10^{\circ}C$ for 28 days. In the baechoo-kimchi, the number of aerobic bacteria increased with time. The number of psychrotrophilic bacteria maintained their numbers $(10^4CFU/g)$ in the kimchi during the fermentation. Coliforms and E. coli were not detected in the kimchi. The pH of kimchi decreased and the acidity of kimchi increased over time. Lactic acid bacteria, which are representative of fermentative microorganisms in the kimchi process showed rapid growth in the earlier stage of fermentation and increased steadily after 7 days. The counts of lactic acid bacteria were at a level of $10^4CFU/g$ early in the fermentation stage, reaching a level of $10^8CFU/g$ after 14 days, and at this point pH was 4.18 and acidity reached 0.63, indicating that the optimal state of kimchi fermentation. This study suggests that the lactic acid bacteria which were proliferated in kimchi during the ripening and fermentation could contribute to improving the taste and flavor of kimchi and inhibit the growth of pathogenic microorganisms that might exist in kimchi.

• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.335-342
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• 2015

We conducted a study on mukeun (long-term fermented) kimchi ripened over one year in an attempt to develop an alternative salt and improve the quality of low-salt kimchi. However, few studies have focused on mukeun kimchi that has been fermented for a short time in different salinity conditions. Therefore, the aim of this study was to investigate the physicochemical characteristics that occur during the fermentation of mukeun kimchi samples produced with different conditions of salinity and fermentation temperature. Kimchi samples were produced at 3 different salinity levels: 1.6%, 2.4%, and 3.2%. Previous studies revealed that the optimum fermentation time at pH 4.1 was 128 hours at $18^{\circ}C$ and 417 hours at $12^{\circ}C$; furthermore, the samples were stored for 12 weeks under the condition of $-1^{\circ}C$ after fermentation. Total cell increased on week 0 of storage and decreased according to the storage period. Total cell was the highest at 3.2% salinity and had a high value at $18^{\circ}C$ temperature during the storage period. Based on the physiochemical results, mukeun kimchi at a salinity of 3.2% can be fermented for a short time, and low-salt kimchi at a salinity of 1.6% and fermented at $18^{\circ}C$, is similar to mukeun kimchi at 2.4% salinity.