• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1467-1474
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• 2013

To develop a starter culture system for the fermentation of mukeunji, we introduced lactic acid bacteria and yeast isolated from mukeunji into kimchi fermentation as a single or a mixed culture. On evaluating mukeunji flavor, we found that the mixed starter kimchi prepared with two strains, ML17 and MY7, gave the best sensory score. These strains were identified as Lactobacillus (Lb.) curvatus ML17 and Saccharomyces (S.) servazzii MY7 by molecular identification method. The fermentative characteristics of starter kimchi were investigated by measuring changes in the physicochemical and microfloral characteristics during the fermentation. The decrease in pH and increase in acidity in the starter kimchi were faster compared to respective values of control kimchi. There was a gradual decrease in hardness of starter kimchi, which was still slow compared to hardness decrease in control kimchi. Microbial analysis of starter kimchi revealed that Lb. curvatus ML17 and S. servazzii MY7 were the dominant organisms during the entire fermentation period. The lactic acid and citric acid contents of starter kimchi were higher than those of the control kimchi after 90 days of fermentation. By sensory evaluation, the starter kimchi scored higher in appearance, mukeunji flavor, sourness, carbonated flavor, savory taste, texture, and overall acceptability, but lower in off-flavor than the control kimchi.

• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.22-31
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• 1999

Saccharomyces fermentati and Leuconostoc mesenteroides were isolated from a traditional kimchi, and then the Leu. mesenteroides was mutated to the acid-tolerant mutant Leu. mesenteroides M-l00. In the result of growth properties in MRS broth with various pHs adjusted with HCl and acid solution (latic acid:acetic acid=1:2), an acid-tolerant mutant Leu. mesenteroides M-100 showed more increased ability for growth than its wild strain at various temperatures. The strains were used as starters for the fermentation of kimchi. The experiments were performed with classified experimental groups (Group I, control kimchi; Group II, addition of YK-19 only; Group III, addition of M-100 only; Group IV, addition of mixture of M-100 and YK-19), and their pH, total acidity, reducing sugars content, organic acid productivity, organoleptic tests, and microfloral changes were compared. As a result, in pH and acidity, the optimal ripening period of Group IV was about 13.5 days (i.e. from the 8.5 to 22 days of fermentation). This result indicates that the optimal ripening period of Group IV was about 1.5 times longer than that of Group I. Furthermore, Group IV was edible to 28 days of fermentation. In addition, high contents of succinc acid was observed in Group IV. Group IV was also highly ranked on the organoleptic test. During the fermentation of kimchi, the number of Leuconostoc sp. in group I reduced after 7 days; however, the number of Leuconostoc sp. in Group II, III, and IV decresed after 14 days of fermentation. An especially high number of Leu. sp. was observed in Group IV, and this gave better flavor of kimchi than any other during the whole fermentation period. Citric acid, tartaric acid, succinic acid, fumaric acid, and lactic acid were detected in the kimchi, and a significant increase in the concentration of lactic acid during fermentation was observed in the all experimental groups.

• Food Science and Preservation
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• v.18 no.5
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• pp.786-794
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• 2011

To investigate the sanitary-quality level of commercial kimchi in South Korea, the pH, acidity, and microbial-flora changes in the kimchi were determined. Samples of kimchi produced by three different manufacturers (a small grocery store, a small/medium-sized enterprise, and a large food company) were collected. Freshly made kimchi was purchased and fermented at $10^{\circ}C$ for 10 days. The pH of the commercial kimchi on the purchased day was approximately pH 5.8, and that on the $10^{th}$ day of fermentation was ${\simeq}pH$ 4.1. The kimchi purchased from a large company showed a more rapid decline in pH level during fermentation. The saltiness of the kimchi purchased from a medium-sized company was slightly higher than those of the other commercial kimchi samples. The saccharinity index of the kimchi produced by a small grocery store was higher than those of the other samples, and its value deviation was also higher than those of the other commercial kimchi samples. A higher total viable-cell count and a higher lactic-acid bacteria (LAB) count were detected in the kimchi from the large food company at the beginning of fermentation compared to the samples of the two other kimchi manufacturers. The highest cell numbers of gram-positive bacteria (except LAB) and coliform bacteria were detected from the small-grocery-store kimchi, but the coliform bacteria count gradually decreased during fermentation although such bacteria were still detected until the $10^{th}$ day of fermentation. In contrast, coliform bacteria were not detected in the samples from the medium-sized and large food companies. Yeast, which is detected in over-ripened kimchi, was detected in the unfermented kimchi from the small grocery store, which had a below-0.36% acidity level. The gram-positive bacteria (except LAB) that were detected in all the tested commercial kimchi samples were determined to be Bacillus spp., and the gram-negative bacteria were determined to be Escherichia coli, Enterobacter spp., Sphingomonase spp., and Strenophomonas spp. The proportions of all the aforementioned bacteria in the kimchi samples, however, were different depending on the samples that were taken. These results indicate that a more sanitary kimchi production process and a more systematic kimchi production manual should be developed to industrialize and globalize kimchi.

• Korean journal of food and cookery science
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• v.31 no.6
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• pp.725-732
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• 2015

This study was conducted to evaluate the effects of ethanol on the prolongation of the shelf-life of kimchi paste. Kimchi paste was prepared by adding 0.5~3.0% ethanol, and then stored at $4^{\circ}C$ for 35 days. The retardation of kimchi paste fermentation was evaluated by measuring chemical, microbial, and sensory characteristics. Titratable acidity and pH showed a slight difference, depending on the ethanol concentration. The titratable acidity showed the low content in kimchi paste with 3.0% ethanol during fermentation, whereas the pH showed a reverse tendency, indicating that fermentation was inhibited under a high ethanol concentration. The changes in the sugar-reduced contents were similar to that of the pH. The growth of microorganisms such as total aerobic bacteria, lactic acid bacteria, yeasts and molds in kimchi paste during fermentation were inhibited by ethanol, and the addition of 3.0% ethanol was most effective to inhibit the microbial growth. The number of coliform bacteria was decreased during fermentation of kimchi paste and not detected in any sample at 35 days, except for kimchi paste with 3.0% ethanol. In sensory evaluation, the addition of 0.5~1.5% ethanol in kimchi paste was showed no significant difference on sensory properties compared to the kimchi paste without ethanol (p<0.05). As a result, it is considered that the addition of 1.5% ethanol is the most appropriate to maintain the quality of kimchi paste, without the changing the flavor.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.924-931
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• 2004

A bacteriocin-producing lactic acid bacterium, which strongly inhibited the Lactobacillus plantarum recognized as an important acid spoilage microorganism in kimchi fermentation, was isolated from kimchi. From morphological, physiological, sugar fermentation, biochemical tests, and l6S rDNA sequencing results, the isolate was identified as an Enterococcus sp. and designated as Enterococcus sp. K25. The bacteriocin produced by Enterococcus sp. K25 inhibited several Gram-positive bacteria, including Lb. plantarum, whereas it did not inhibit Gram-negative bacteria and yeasts. Optimal temperature and pH for the bacteriocin production were $25^\circ{C}$ and 5.5, respectively. Enterococcus sp. K25 was applied to kimchi manufacturing alone and together with other preservatives (i.e., chitosan and fumaric acid). In addition, growth of lactic acid bacteria, pH, and titratable acidity (TA) were measured during aging at $5^\circ{C}$ and $10^\circ{C}$. Inoculation of Enterococcus sp. K25 together with fumaric acid showed the most synergistic effect on extension of kimchi shelf-life. Compared to control (no addition), the treatment prolonged the kimchi shelf-life up to 6 days, whereupon the eight-point TA value recognized as the edible limit was reached.

• Food Science and Preservation
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• v.3 no.1
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• pp.33-38
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• 1996

To investigate the food preservative effects of mustard seed(Brassica juncea), mustard seed were added to Kimchi. Titratable acidity of Kimchi treated with mustard seed was higher than that of non-treated control at initial stage, but it was lower than control after 2 days of fermantation. The number of bacteria and lactic acid bacteria increased rapidly at the initial stage of fermentation and reached plateau by 2 days of fermentation. The number of bacteria and lactic acid bacteria of Kimchi treated with mustard seed was lower than that of control, and the more mustard seed added the less bacteria and lactic acid bacteria were observed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.869-874
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• 1998

The effect of chitosanoligosaccharide(CTO) on kimchi fermentation was investigated to see the optimal CTO concentration adding into Kimchi. Lactobacillus plantarum and Leuconostoc mesenteroides were cultured in flasks under the condition of various CTO concentrations. In the case of Lactobacillus plantarium, the growth was inhibited in the degree with 52, 79 and 100% at the concentration of 0.005, 0.007, 0.05% CTO after 14 hours culture, respectively. The growth of Leuconostoc mesenteroides was significantly inhibited in the degree with 7,33 and 90% at the concentration of 0.002, 0.003 and 0.004% CTO after the culture, respectively. Kimchi was formulated with variious CTO concentrations(0.005~0.2%) and fermented at 2$0^{\circ}C$ during 12 days. The fermentation periods were increased 2~6 times more than that of control(0% CTO). Also, off-flavour by adding CTO was insignificant in all the kimchi samples.

• Journal of Microbiology and Biotechnology
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• v.29 no.4
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• pp.558-561
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• 2019

This study aimed to understand the survival and growth patterns of bacteriophage-sensitive Weissella and Leuconostoc strains involved in kimchi fermentation. Dongchimi kimchi was prepared, and Weissella and Leuconostoc were co-cultivated in the dongchimi broth. Weissella cibaria KCTC 3807 growth was accompanied by rapid lysis with an increase in the bacteriophage quantity. Leuconostoc citreum KCCM 12030 followed the same pattern. The bacteriophage-insensitive strains W. cibaria KCTC 3499 and Leuconostoc mesenteroides KCCM 11325 survived longer under low pH as their growth was not accompanied by bacteriophages. The bacteriophage lysate of W. cibaria KCTC 3807 accelerated and promoted the growth of Leuconostoc. Overall, our results show that bacteriophages might affect the viability and population dynamics of lactic acid bacteria during kimchi fermentation.

• Journal of Nutrition and Health
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• v.18 no.1
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• pp.36-45
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• 1985

The effects of glucose, lactose, sucrose, and potato starch on kimchi fermentation and on the stability of ascorbic acid were investigated at $7^{\circ}C$. Kimchi samples with the sugars showed the higher PH and lower total acidity until 9th day of fermentation than kimchi without sugar. Changes in the pH and total acidity were not significantly different among the samples after the 12th day. Addition of the sugars did not show any effects on the growth of lactobacilli through the fermentation period. The amounts and changes in ascorbic acid content during the fermentation did not differ significantly between the control and sugar - added samples. Ascorbic acid in most samples decreased continuously by the 9th day of fermentation. After then the vitamin increased in all the samples and then again decreased slowly after 18th day. From the multiple comparison tests the 10- panel members indicated the better flavor of sugar - added samples than control sample. However the differences in flavor were not significant.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.348-355
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• 2021

Bacteriophages (phages) are known determinants of kimchi microbial ecology. Lactobacillus plantarum is related to kimchi over-acidification during the late stages of kimchi fermentation. A phage infecting Lac. plantarum was isolated from kimchi and characterized. The phage population for kimchi in a market was 2.3 log particles/mL, which corresponded to 32% of the bacterial population on a log scale. The isolated phage was designated as ΦLP12116. ΦLP12116 which belonged to the Siphoviridae family and has a very narrow host range, infecting only Lac. plantarum. The phage was stable at a lactic acid concentration of 1.0% and pH 4.0 at 4℃, indicating that it could survive in kimchi. In the kimchi extract broth treated by the phage, the growth of Lac. plantarum KCCM 12116 was inhibited by 2.2 log CFU/mL compared to the growth in non-phage-treated broth. Therefore, this study suggests that the growth of Lac. plantarum, which is known as an acid-producing strain during late fermentation in kimchi, may be controlled using the phage.