• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.935-941
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• 2022

The purpose of this study was to investigate whether the activity of ginsenoside metabolites and the intestinal immunity antioxidant activity were remarkably improved by lactic acid bacteria fermentation by adding a small amount of ginsenoside to the complex extracts of fruits and vegetables. It was confirmed that the increase in intestinal immunity antioxidant activity due to synergistic effect was observed in the fruit-vegetable extract containing ginsenoside compared to the ginsenoside-only extract or the fruit-vegetable extract. Then, by adding ginsenosides by content, the concentration of ginsenosides that can obtain a synergistic effect according to the fermentation of lactic acid bacteria was determined. As a result, it was confirmed that a synergistic effect was exhibited when lactic acid bacteria were fermented and extracted by mixing ginsenosides in a mass ratio of 3 to 10% with respect to the mass of the fruit-vegetable mixture. As a result, when treated at a concentration of 200 ㎍/ml, the fruit-vegetable complex extract containing ginsenoside metabolites inhibited the generation of NO by about 60% compared to the complex extract containing no ginsenoside, The expression of IL-1β was suppressed by 63%, the expression of IL-6 by 69%, and the expression of TNF-α by 76%, confirming that the intestinal immune antioxidant properties were significantly improved.

• Journal of Microbiology and Biotechnology
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• v.29 no.10
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• pp.1580-1590
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• 2019

Capsaicinoids in red pepper powder are known to show anti-bacterial effects; however, their effects during kimchi fermentation are not known. This study aimed to investigate the effects of various concentrations of capsaicinoids on kimchi fermentation. Five sets of kimchi samples were prepared using 0 mg/kg (control), $98.34{\pm}5.34mg/kg$ (mild), $243.47{\pm}3.71mg/kg$ (medium), $428.63{\pm}30.78mg/kg$ (hot), and $1,320.49{\pm}28.27mg/kg$ (extreme) capsaicinoid. The characteristics of each kimchi sample, including pH, acidity, organic acid, sugars, sugar alcohol, capsaicinoid content, and microbial community were periodically investigated during fermentation. Kimchi with red pepper powder shows significantly higher acidity than control kimchi, whereas pH values were the same. Organic acid in kimchi with red pepper powder was higher than in control kimchi, probably caused by higher lactic acid bacteria (LAB) counts in kimchi samples with red pepper powder. Our results show that addition of red pepper powder decreased Leuconostoc spp. counts in the bacterial community. In particular, Lactobacillus sakei and Leuconostoc gelidum counts increased and decreased, respectively, with increasing capsaicinoid content of red pepper powder added to kimchi. Overall, the results of this study indicate that physicochemical properties and LAB such as L. sakei and L. gelidum are influenced by capsaicinoid content. However, further studies are necessary to investigate the effects of the percentage of red pepper powder in kimchi on fermentation to provide practical guidelines for producing standardized kimchi.

• Journal of Life Science
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• v.30 no.6
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• pp.491-500
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• 2020

Lactic acid bacteria are widely known to prevent and treat intestinal health conditions, heart disease, depression, and obesity. In Korea, such bacteria are commonly consumed through various fermented foods, although most are isolated from kimchi, and research on the lactic acid bacteria in fermented seafood is insufficient. This study was therefore conducted to observe changes in bacterial flora according to the culture date of lactic acid bacteria in the fermentation of traditional Korean Gajami Sikhae produced in Pohang and to isolate the bacteria of probiotic value. The bacteria were periodically isolated and identified from date of preparation to 50 days after preparation to investigate which Lactobacillus are involved in Gajami Sikhae. As fermentation progressed, it was confirmed that Pediococcus sp. and Lactobacillus sp. participate predominantly in the early and later periods of fermentation, respectively. During the entire fermentation period, 170 isolates were screened, and the following five species were found to be involved: Pediococcus pentosaceus, Pediococcus inopinatus, Leuconostoc mesenteroides, Lactobacillus brevis, and Lactobacillus plantarum. Five strains of these species were selected through acid and bile tolerance tests, and their coaggregation, autoaggregation, hydrophobicity, antibacterial, and antioxidant activities were then evaluated. As a result, it is thought that L. brevis GS1022, which has excellent digestive fluid resistance, and P. inopinatus GS316, which has excellent cohesiveness, may be useful as probiotic strains.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.299-304
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• 2019

Yogurt was prepared with different substitution ratio [10, 20, 30, and 50% (w/w)] of skim milk with enzymatically saccharified Korean rice wine lees powder (eKRWLP) and fermented with commercially available mixed lactic acid bacteria (Bifidobacterium longum, Lactobacillus acidophilus, Streptococcus thermophilus) at $40^{\circ}C$ for 18 h. Fermentation characteristics were evaluated in terms of acid production (pH and titratable acidity) and viable cell counts of lactic acid bacteria. The pH of yogurts decreased with increasing eKRWLP substitution ratio of skim milk. After 12 h fermentation, titratable acidities of eKRWLP substitution and control (yogurt made without eKRWLP) were 0.84~1.04% and 0.93%, respectively. The titratable acidities of yogurts prepared with 10 and 20% substitution ratio increased than that of the control yogurt, but titratable acidities of yogurts of 30 and 50% substitution ratio decreased. After 9 h fermentation, the number of viable lactic acid bacterial cell were increased to 8.18~8.24 log CFU/g in all yogurts. In sensory evaluation, there were similar preference for eKRWLP yogurts prepared with 10 and 20% substitution ratio and the control. When eKRWLP substitution and control yogurts fermented for 9 h were incubated at $4^{\circ}C$, their pHs and titratable acidities were slightly changed but the number of viable lactic acid bacteria were well maintained above $10^7CFU/g$ for 11 days in yogurts prepared with 10 and 20% substitution ratio among eKRWLP substitution yogurts. These results suggest that eKRWLP can be used as substituent of skim milk and the optimum substitution ratio is around 10~20%.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.40-46
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• 2013

A variety of nuruk were collected from various provinces in Korea, and their microflora profiles were analyzed at the species level. A total of 42 nuruk samples were collected and when the viable cell numbers in these nuruk were enumerated, the average cell numbers of bacteria, fungi, yeast, and lactic acid bacteria from all nuruk were 7.21, 7.91, 3.49, and 4.88 log CFU/10 g, respectively. There were no significant differences in viable cell numbers of bacteria or fungi according to regions collected. Bacillus amyloliquefaciens and B. subtilis were the predominant bacterial strains in most samples. A significant portion, 13 out of 42 nuruk, contained foodborne pathogens such as B. cereus or Cronobacter sakazakii. There were various species of lactic acid bacteria such as Enterococcus faecium and Pediococcus pentosaceus in nuruk. It was unexpectedly found that only 13 among the 42 nuruk samples contained Aspergillus oryzae, the representative saccharifying fungi in makgeolli, whereas a fungi Lichtheimia corymbifera was widely distributed in nuruk. It was also found that Pichia jadinii was the predominant yeast strain in most nuruk, but the representative alcohol fermentation strain, Saccharomyces cerevisiae, was isolated from only 18 out of the 42 nuruk. These results suggested that a variety of species of fungi and yeast were distributed in nuruk and involved in the fermentation of makgeolli. In this study, a total of 64 bacterial species, 39 fugal species, and 15 yeast species were identified from nuruk. Among these strains, 37 bacterial species, 20 fungal species, and 8 yeast species were distributed less than 0.1%.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.119-127
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• 2013

Twenty-three strains of Leuconostoc species and 45 strains of Weissella species inhibiting the growth of Lactobacillus sakei, one of the most populous lactic acid bacteria in over-ripened kimchi, were isolated from kimchi in our previous study. Among these hetero-fermentative 68 strains, Leuconostoc mesenteroides CK0128, Weissella cibaria CK0633, and W. cibaria KK0797 exhibited a relatively high survival rate in MRS medium, which was adjusted to pH 4.3 using an acid mixture consisting of acetic and lactic acids, and produced a large amount of exopolysaccharides. The culture supernatants of 3 strains were fractionated by a molecular weight cutter and lyophilized. The fractions with a molecular weight smaller than 3,000 Da showed antagonistic activity against Staphylococcus aureus and Lb. sakei. The anti-bacterial substances were very stable to heat treatments ($121^{\circ}C$, 15 min) and active at acidic conditions below pH 5. ${\alpha}$-Amylase, lipase, and proteolytic enzymes (proteinase K and pepsin) did not affect their activities. These non-proteinaceous anti-bacterial substances inhibited the growth of several food pathogens.

• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.23-28
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• 2014

Mul-kimchi was prepared with addition of 0.025, 0.05, and 0.1% (w/v) chlorella powder and fermented at $10^{\circ}C$ for 6 days. Quality characteristics of the Mul-kimchi were evaluated in terms of acid production (pH and titratable acidity) and lactic acid bacterial counts during fermentation. The addition of chlorella powder stimulated the growth of lactic acid bacteria and significantly enhanced the acid production. After 3 days fermentation, titratable acidity of chlorella Mul-kimchi was 0.12-0.14% and was higher than that (0.11%) of Mul-kimchi made without chlorella. The acid production and the number of viable lactic acid bacterial cell increased with increasing the concentration of added chlorella powder. The sensory score of Mul-kimchi added with 0.05% chlorella powder showed the highest values in taste and overall acceptability among the tested Mul-kimchi preparations. When chlorella Mul-kimchi preparations incubated for 3 days were kept at $4^{\circ}C$ for 19 days, their quality characteristics were well maintained through storage period. According to sensory score and storage ability, the optimum concentration of chlorella powder was around 0.05%.

• Journal of Life Science
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• v.31 no.4
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• pp.367-376
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• 2021

This study evaluated the changes in the pH, acidity, lactobacillus and total bacterial counts, and sensory evaluation of Dolsan leaf mustard Kimchi (DLMK) after incubation for 50 days at 4℃ in the presence of one of three lactic acid bacteria (LAB); Weissella kimchii (W.k.), Leuconostoc gelidum (L.g.), and Leuconostoc mesenteroides (L.m.). The pH ranged from 5.12 to 5.62 and the acidity varied from 0.62% to 3.77% upon the addition of a 2% salt solution to the DLMK prepared using the three LAB. Overall, the LAB counts decreased rapidly from day 10 to day 20 of fermentation, whereas the total bacterial count decreased during the 50 days of fermentation. The pH and acidity in the DLMK ranged from 5.22 to 5.61 and from 0.91% to 4.41%, respectively, in the absence of the 2% salt solution. The LAB count decreased until 20 days and then increased thereafter, whereas the total bacterial count decreased until 20 days and then increased until 50 days. The condiments treated with or without the 2% salt solution showed a gradual decrease in appearance, flavor, salinity, hot taste, and overall acceptability as fermentation time increased. In addition, DPPH radical scavenging activity was high for 2% W. k. and 2% L. m., and ACE inhibitory activity was the highest, at 70.38% in the marinated condiments fermented at 10℃ for 8 days. Thus, this condiment production method may be useful for DLMK and other Kimchi types.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.936-949
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• 2018

Changes in microbial community and physicochemical traits of chicken summer sausage made from spent layer thigh added with different level (0%, 0.1%, 0.3%, and 0.5% w/w) of ground chopi (Zanthoxylum piperitum) during manufacture were analyzed. The microbial community was profiled and analyzed by sequencing 16S rRNA gene using Illumina MiSeq. Samples were taken from raw sausage batter, after 15 h of fermentation, 8 h of cooking including cooling down, and 7 d of drying. The final pH of the sausage was reduced by the addition of ground chopi. However, no clear effect on water activity was observed. Ground chopi inhibited the development of red curing color after fermentation as it exhibited antimicrobial effect. However, the effect on species richness and microbial composition after cooking was unclear. Ground chopi delayed lipid oxidation during manufacture and the effect was dependent on the addition level. Fermentation reduced the species richness with a dominancy of lactic acid bacteria. The profile of microbiota in the raw batter was different from other stages, while the closest relationship was observed after cooking and drying. Proteobacteria was predominant, followed by Firmicutes and Bacteroidetes in raw samples. Firmicutes became dominating after fermentation and so forth, whereas other predominant phylum decreased. At genus level, unclassified Lactobacillales was the most abundant group found after fermentation and so forth. Therefore, the overall microbial composition aspects were mainly controlled during fermentation by the abundance of lactic acid bacteria, while bacterial counts and lipid oxidation were controlled by cooking and the addition of ground chopi.

• Applied Biological Chemistry
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• v.31 no.3
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• pp.255-260
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• 1988

The optimum conditions for lactic acid fermentation by Lactobacillus acidophilus in the media containing malt syrup, skim milk or skim milk and malt syrup were studied to develope marketable fermented beverages from barley. The optimum sugar concentration of malt syrup was $10^{\circ}$ Bx. Addition of skim milk to malt syrup enhanced bacterial growth and acid formation. The best flavor of the product was obtained from the media containing 5% skim milk and sterilized at $90^{\circ}C$ for 30 minutes. Optimum temperature and pH for the formentation were $40^{\circ}C$ and 6.0, and bacterial cells grew logarithmically upto 16 hours.