• Journal of Life Science
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• v.33 no.4
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• pp.325-333
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• 2023

This study compared and analyzed the microbial composition and physicochemical characteristics of kimchi (gimjang kimchi) and mukeunji (aged kimchi). Commercial kimchi and mukeunji products were purchased through an online market. After an analysis of physicochemical characteristics, the pH of the mukeunji samples was found to be lower and the acidity higher than in the kimchi samples. There was no significant difference in salinity between kimchi and mukeunji, but the sugar content was higher in the kimchi samples. The phylogenetic diversity index, which incorporates phylogenetic difference between species, was significantly higher in mukeunji than in the kimchi. The most dominant order in both groups was Lactobacillales, but several lactic acid bacteria, such as the Pediococcus and Lactobacillus species, which may be more acid tolerant or more competitive, are relatively predominant in mukeunji. Beta set-significance analysis based on two different distance metric results revealed that microbial distributions of population were different at the statistical confidence level (p<0.001). We investigated the effect of respective species on total microbial community using the LEfSe (linear discriminant analysis effect size) mechanism. According to the results of LEfSe testing, a relatively higher abundance of Weissella kandleri in kimchi and a higher abundance of Pediococcus inopinatus in mukeunji have the greatest influence on the differences in microbial structure between the two groups.

• Journal of the Korean Society of Food Culture
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• v.34 no.2
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• pp.217-223
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• 2019

This study aimed to evaluate the characteristic differential between whole cabbage kimchi (pogi kimchi) and sliced cabbage kimchi (mat kimchi) during kimchi fermentation at $6^{\circ}C$. The difference of microbial and physicochemical properties was investigated until 6 weeks. For the changes in the microbial flora, both kimchi samples exhibited a continuous increase in total aerobic bacteria and lactic acid bacteria (LAB) population size up to 2 weeks followed by a stationary phase until 5 weeks. Interestingly, the number of LAB of mat kimchi was overall higher than that of pogi kimchi during kimchi fermentation. We speculate that mat kimchi has in a more advantageous growth condition than pogi kimchi for microbial growth because small kimchi cabbage size appropriately derives nutritional supply in order to increase the LAB growth. During lactic fermentation at $6^{\circ}C$, physicochemical changes in the pH, salinity, and titratable acidity was observed to be no significant differences between two types of kimchi. Furthermore the contents of organic acids such as oxalic acid, citric acid, malic acid, lactic acid, fumaric acid, and acetic acid was not significantly different (p>0.05) between both kimchi samples as well as the contents of total free amino acid.

• Korean journal of food and cookery science
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• v.1 no.1
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• pp.18-26
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• 1985

The effect of 0.05% Sorbic acid on the Kimchi fermentation and stability of ascorbic acid were investigated at 23~$25^{\circ}C$. The results are as follows. 1. Kimchi with sorbic acid showed a higher pH and a lower total acidity in general, as compared with the control Kimchi. 2. Kimchi with sorbic acid contains more ascorbic acid for the fermentation period. Especially showed the higher hydro ascorbic acid than control Kimchi. 3. The Lacticacid bacteria isolated from Baechu Kimchi and Dongchimi are identifi-ed as Leuconostoc mesenteroides, Lactobacillus Plantarum, Lactobacillus brevis, Streptococcus faecalis, Pediococcus pentosaceus. 4. The effect of sorbic acid upon the growth of Lactic acid bacteria and acid prod-ucibility is found least in Lactobacillus Plantarum, and most in Leuconostoc mesenter-oides. 5. The changes of Lacticacid bacteria occured during Kimchi fermentation curbed Leuconostoc mesenteroides most of all in Baechu Kimchi and Dongchimi with sorbic acid, while the least influence was had on Lactobacillus plantarum. Expecially, yeast wae completely curbed. 6. A result of a sensory evaluation reveals that a better taste is derived from the control Kimchi, with a significant difference, in pH4~4.3, whereas from Kimchi with sorbic acia in pH 3.7~3.8.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.30-36
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• 1996

This study was conducted to investigate the changes in chemical, microbial, sensory characteristics and volatile flavor components of wooung(burdock, Arctium lappa, L) kimchi during fermentation at 15$^{\circ}C$, Three types(A, B, C) of wooung kimchi were prepared. Sample A was prepared with basic ingredients, in the other hand, sample B was prepared with all sorts of ingredients. These samples were mixed after salting the sliced burdock with 4% brine for 30min. Sample C was prepared mixing with all sorts of ingredients after blanching the sliced burdock with 2% vinegar solution. pH decreased slowly until 3 day, and then decreased rapidly for 4~7 days in all samples. Total acidity increased gradually in all samples. The changes of pH and total acidity were the sample C and were the greatest in sample B. The reducing sugar contents decreased slowly until 7 day, and decreased rapidly for 8~14 days in sample A and B, and at 10 day in sample C, respectively. The numbers of lactic acid bacteria and total bacteria of sample B were much greater than those of other sample. In sensory evaluation, sample B exhibited the best scores and sample C showed the worst scores in all characteristics. The major volatile components in wooung kimchi were identified as ethanol, hexanal, 2-hexenal, disulfide dl- 2-prophenyl, zingiberene and $\beta$-sesquiphellandrene. The relative amounts of hexanal, 1-hexanol and ethanol were decreased, while the relative amounts of acetic acid ethyl ester, 3-htdroxy-2-butanone and acetis acid were increased gradually during fermentation.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.44-54
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• 2018

To maintain the best quality of kimchi during long-term storage, we developed a fermentation storage mode for the kimchi refrigerator. The optimal kimchi fermentation temperature was determined to be $6^{\circ}C$ with fermentation time of 4-7 days in winter and 3-5 days in spring and fall. Based on these results, the fermentation storage mode conditions were programmed to consist of a fermentation temperature of $6^{\circ}C$ and fermentation times of 111 h in winter and 58 h in spring/fall. When kimchi was stored under the developed fermentation storage mode conditions, the total acidity of kimchi was almost the same as that of the control kimchi (stored $-2-\;-1^{\circ}C$ for 12 weeks). However, the number of lactic acid bacteria (LAB) and Leuconostoc sp. in kimchi were higher ($10^1-10^2CFU/mL$) than those in the control kimchi during storage. In addition, kimchi fermented and stored under the fermentation storage mode clearly received higher scores for overall preference than the control kimchi.

• Food Science and Preservation
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• v.22 no.5
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• pp.758-767
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• 2015

Red pepper powder sensitive to aflatoxins contamination is major ingredients of kimchi. This study was conducted to investigate the effect of lactic acid bacteria (LAB) on the changes in aflatoxin levels during kimchi fermentation. Baechu kimchi was contaminated with aflatoxins ($B_1$, $B_2$, $G_1$, and $G_2$) and inoculated with LAB (Lactobacillus plantarum and Leuconostoc mesenteroides), and the following characteristics were investigated for 8 weeks: pH, titratable acidity, salinity, microbial properties, and aflatoxin levels. The pH decreased rapidly during storage, and the titratable acidity was increased. The salinity of the samples was shown to increase from 2.30 to 2.40%. The total number of aerobic bacteria and lactic acid bacteria in kimchi inoculated with LAB was significantly higher than that of the others. Yeast and molds were detected at approximately 1~3 log CFU/g during storage. Coliforms were detected in the control after 4 weeks, whereas in other samples they were not detected until after 2 weeks. The aflatoxin levels reduced during kimchi fermentation. The average reduction rate of aflatoxin levels during kimchi fermentation was 8.39%, but in kimchi inoculated with Lac. plantarum and Leu. mesenteroides, the rate were 25.16 % and 27.86%, respectively. These results showed that aflatoxins can be removed by LAB during kimchi fermentation.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.4
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• pp.413-422
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• 2013

This study investigates the kimchi from Jangsu area (JSK) and its comparison with commercial kimchi (CMK). We conducted a sensory evaluation for the pH, titratable acidity, salinity, hunter's color values and mechanical characteristics of kimchi. The pH of JSK is significantly higher than CMK throughout the fermentation (p<0.001). At 15 days, JSK reached the stage of optimal maturity for pH 4.23~4.55 and CMK showed pH 3.96~4.00 as conditions after the optimal maturity (p<0.001). From the results of acidity analyses, CMK also showed higher acidity values than JSK (p<0.001), indicating that the rate of fermentation progress was faster in CMK. Salinity of JSK was a litter higher than CMK1 and CMK2 (p<0.001) and JSK indicated significantly higher L, a, b values during fermentation (p<0.001). Moreover, the textural values were significantly higher in JSK2 and JSK3 retaining hardness of the tissues. In the sensory assessment, the color, flavor, crispness, taste, and overall preferences were higher in JSK3 at 15 days and 30 days than CMK. Therefore, it seems necessary for recipe developments of kimchi with local characteristics in order to industrialize kimchi by using alpine crops at Jangsu area.

• Food Science and Preservation
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• v.11 no.1
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• pp.34-37
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• 2004

Calcium powder from whey (WCF) was added to enrich the calcium content of kimchi, and the mixing ratios of it to salted Chinese cabbage were 0.5, 1.0 and 1.5％. Quality characteristics of kimchi such as pH, titratable acidity, reducing sugar content and microbial loads were measured during fermentation at 10$^{\circ}C$. Kimchi samples with WCF showed a higher level in pH and titratable acidity than that of control during fermentation. Kimchi having higher WCF maintained a higher in pH and titratable acidity, and titratable acidity was above 1.0％ about 12 days in kimchi sample with 0.5％ WCF. Reducing sugar content was steadily decrease after 5 days, and control maintained a higher than others. Microbial load was similar until 10 days, but control was lower than kimchi samples with WCF. Based on the titratable acidity, kimchi with WCF had a limitation in shelf life.

• The Korean Journal of Food And Nutrition
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• v.30 no.5
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• pp.1007-1014
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• 2017

To compare functional Chinese cabbage('Amtak' baechu; F1 hybrid cultivar between Brassica rapa and B. perkinensis, AB) with general Chinese cabbage ('Chunkwang' baechu; general spring cultivar, CB), two kinds of kimchi(ABK and CBK) prepared with AB and CB cultivar were fermented at $10^{\circ}C$ for 10 days. Their fermentative characteristics and anti-proliferative activities against mouse carcinoma cell lines were investigated. General kimchi(CBK) showed mature pH on the $6^{th}$ day of fermentation, whereas functional kimchi(ABK) reached pH on the $9^{th}$ day. CBK also exhibited acidity of mature stage on the $6^{th}$ day, but ABK reached mature acidity on the $9^{th}$ day. Although ABK and CBK were salted in the same condition, ABK had lower salinity than CBK, throughout the fermentation time. The highest total bacterial and lactic bacterial counts of CBK showed on the $8^{th}$ day of fermentation, but ABK showed the highest total bacterial and lactic bacterial counts on the $10^{th}$ day. The texture of ABK was harder than CBK for fermentation time. This seems to be corrleated with the slower fermentation rate of ABK. ABK showed significantly higher anti-proliferative activity (54.6% cell viability of control) in B16BL6 at $1,000{\mu}g/mL$. ABK was also higher in anti-proliferative activity than CBK throughout the fermentation time. However, there was no significant difference in the anti-proliferative activity of ABK between the fermentation times. In conclusion, fermentation of ABK showed a better texture, due to the slow fermentation rate and more anti-proliferative activity against mouse carcinoma cell line than those of CBK.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.429-437
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• 2020

This study aimed to investigate the change in physicochemical properties and lactic acid bacterial communities during kimchi fermentation at different temperatures (8, 15, and 25 ℃) using two molecular genetics approaches, multiplex polymerase chain reaction and 16S rRNA gene sequencing. The pH during fermentation at 8, 15, and 25 ℃ decreased from 6.17 on the initial fermentation day to 3.92, 3.79, and 3.48 after 54, 30, and 24 days of fermentation, respectively, while the acidity increased from 0.24% to 1.12, 1.35, and 1.54%, respectively. In particular, the levels of lactic acid increased from 3.74 g/L on the initial day (day 0) to 14.43, 20.60, and 27.69 g/L during the fermentation after 24, 18, and 12 days at 8, 15, and 25 ℃, respectively, after that the lactic acid concentrations decreased slowly. The predominance of lactic acid bacteria (LAB) in the fermented kimchi was dependent on fermentation stage and temperature: Lactobacillus sakei appeared during the initial stage and Leuconsotoc mesenteroides was observed during the optimum-ripening stage at 8, 15, and 25 ℃. Lac. sakei and Lactobacillus plantarum grew rapidly in kimchi produced at 8, 15, and 25 ℃. In addition, Weissella koreensis first appeared at days 12, 9, and 6 at 8, 15, and 25 ℃ of fermentation, respectively. This result suggests that LAB population dynamics are rather sensitive to environmental conditions, such as pH, acidity, salinity, temperature, and chemical factors including free sugar and organic acids.