• Food Science and Preservation
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• v.24 no.8
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• pp.1180-1187
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• 2017

Zingiber officinale Roscoe, commonly known as ginger, has long been used as a powerful health-promoting antioxidant that supports cellular health of the human body. The objective of this study was to compare the antioxidant and antimicrobial activities of the samples with aging and fermentation. Antioxidant activities of the samples were compared using total phenol, flavonoid contents, ABTS cation radical scavenging activity and DPPH radical scavenging activity. Antimicrobial activities were also examined using the paper disc method and minimum inhibitory concentration (MIC). Acidity of the fermented ginger (FG) with lactic acid bacteria showed a significantly higher value than that of the ginger (GG). The content of 6-gingerol, a bioactive component in ginger, decreased in all fermented gingers but 6-shogaol which is also one of the main valuable ingredients showed the increased content at ginger fermented with Streptococcus thermophilus and Lactobacillus acidphilus. Flavonoid contents of the FG and GG did not show significant differences. However, ABTS cation radical scavenging activity and DPPH radical scavenging activity were 10-30% increased in the samples with fermentation (p<0.05), respectively. The samples of the disc showed an inhibitory effect on growth of gram positive Staphylococcus aureus and Listeria monocytogenes. Zinger with fermentation showed higher antioxidant and antimicrobial activities. Thus, we conclude that aging and fermentation can be a helpful process to increase the functional effects of ginger.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.257-262
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• 2011

The objective of this study was to investigate the changes in the microbial properties of taurine supplemented Kimchi during fermentation at $6^{\circ}C$ for 46 days. Chinese cabbage was brined in 10% salt solution for the control Kimchi and in 10% salt solution containing 1, 2 or 4% taurine (w/w, based on cabbage) for taurine supplemented Kimchi (Taurine I, II, and III groups, respectively). The pH values of all the groups dramatically decreased after 1-day of fermentation. Total numbers of viable cells were highest at 5-days of fermentation for the control, at 9-days of fermentation for Taurine I, and at 23-days of fermentation for Taurine II and III. The highest numbers of lactic acid bacteria were found at 9-days of fermentation for the control and Taurine I, and at 18-days of fermentation for Taurine II, and at 13-days of fermentation for Taurine III. The fermentation periods required to reach the highest numbers of Leuconostoc bacteria for Taurine I, II and III were longer than that for the control, suggesting that taurine might inhibit the growth of Leuconostoc bacteria during Kimchi fermentation. Based on the results obtained from the present study, it is concluded that adding taurine to the production of Kimchi could delay the ripening period of Kimchi.

• Journal of Animal Science and Technology
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• v.49 no.4
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• pp.539-548
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• 2007

The study was carried out to examine combined effects of packaging and electron-beam irradiation on lipid oxidation and meat color of fermented sausages during storage. Fermented and aged sausages were exposed to electron-beam at 2 kGy. The samples were vacuum or aerobic-packaged with the non-irradiated samples at 4±1℃. Regardless of irradiation, the pH values of vacuum-packaged samples was lower than those of aerobic-packaged ones at 14 day (p<0.05). Total microbes and lactic acid bacteria counts significantly decreased during the storage period (p<0.05). And counts of non-irradiated samples were significantly higher than those of irradiated (2 kGy) samples with aerobic packaging. The TBARS values of 2 kGy-irradiated samples were significantly higher than those of non-irradiated samples. The TBARS values of vacuum packaged samples had lower than those of aerobic-packaged ones (p<0.05). Colors (parameters L*, a* and b* values) tended to decrease as the storage period increased. Redness(a*) and yellowness (b*) of 2 kGy irradiated samples were higher than those of non-irradiated ones (p<0.05). In sensory analysis, irradiated (2 kGy) samples with aerobic packaging had higher off-flavor than non-irradiated ones (p<0.05). Therefore, results indicated that irradiation coupled with vacuum packaging may minimize TBARS values of irradiated sausages during storage.

• Polymer(Korea)
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• v.28 no.3
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• pp.211-217
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• 2004

The sol to gel transition of aqueous solution of block copolymers consisting of methoxy poly (ethylene glycol) (MPEG) and biodegradable polyesters such as $\varepsilon$-caprolactone and L-lactide was investigated as a function of temperature. MPEG-PCL was prepared by ring opening polymerization of $\varepsilon$-caprolactone in the presence of HClㆍEt$_2$O as monomer activator at room temperature. Also, MPEG-PLLA was prepared by ring opening polymerization of L-lactide in the presence of stannous octoate at 115$^{\circ}C$. The properties of block copolymers were investigated by $^1$H-NMR, IR, and GPC as well as the observation of thermo sensitive phase transition in aqueous solution. As the hydrophobic block length increased, the sol to gel transition temperature increased and curve of that steepen to lower concentration. To confirm the gel formation at body temperature, we observed the formation of gel in the mice body after injection of 20 wt% aqueous solution of each block copolymer. After surging, we investigated the gelation in mice. The results obtained in this study confirmed the feasibility as biomaterials of injectable implantation for controlled release of drug and protein delivery.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.235-243
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• 2012

We studied the effect of fermented Rhus verniciflua stem bark (FRVSB) extract (used in herbal med-icine by Koreans) on the microbial growth and enzyme activity of 12 soybean-fermenting microorganisms, including Bacillus spp., lactic acid bacteria, yeast, and other harmful bacteria. The ethanol and methanol extracts of FRVSB inhibited the growth of Bacillus subtilis, Bacillus licheniformis, Bacillus cereus, and Zygosaccharomyces rouxii, and in the disk diffusion assay, their inhibition zone diameters were 11.06-12.23, 12.32-18.38, 11.47-11.84, and 13.59-14.21 mm, respectively. The water extract did not show any inhibitory effect. In fact, the water extract addition enhanced the growth of B. subtilis and B. licheniformis by 1.3-4.5 fold and that of B. cereus by 1.2-1.4 fold. However, the water extract did not affect the growth of Lactobacillus plantarum, Lactobacillus mesenteroides, Saccharomyces cer-evisiae, and Escherichia coli. The addition of water extract increased the amylase and protease activity of B. subtilis and B. licheniformis.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.135-146
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• 2022

Obesity is closely associated with profound dyslipidemia, insulin resistance, and fatty liver disease. Recent reports have suggested that alterations in gut microbiota can be linked to diet-induced obesity. In this study, the anti-obesity effects of Weissella confusa WIKIM51 isolated from kimchi were investigated, as evidenced by: i) reduced lipid accumulation and downregulated adipogenesis-related genes in 3T3-L1 adipocytes; ii) suppressed gains in body weight and epididymal fat mass; iii) reduced serum lipid levels, for example, triglyceride and total cholesterol; iv) increased serum adiponectin levels and reduced serum leptin levels; v) downregulated lipogenesis and upregulated β-oxidation-related genes in the epididymal fat; and vi) altered microbial communities. The collective evidence indicate the potential value of W. confusa WIKIM51 as a functional food supplement for the prevention and amelioration of obesity.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.389-398
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• 2009

Development of expression vectors is important for the basic and applied researches on kimchi LAB (lactic acid bacteria). An expression vector, pSJE6c was constructed by inserting P6C promoter sequence from Lactococcus lactis into pSJE, a shuttle vector for E. coli and Leuconostoc species. To test the efficiency of pSJE6c, aga ($\alpha$-galactosidase) and lacZ ($\beta$-galactosidase) genes were expressed in Lactobacillus brevis 2.14. Compared to the pSJE, expression levels of both genes were increased, indicating P6C promoter was better than indigenous promoters. Enzyme activities of L. brevis cells harboring pSJE6caga (pSJE6c with aga) or pSJE6Z (pSJE6c with lacZ) were 1.5-2 fold higher than those with pSJEaga (pSJE with aga) or pSJEZ (pSJE with lacZ). More RNA transcripts were detected in cells harboring pSJE6c based recombinant plasmid. The results indicated that heterologous gene expressions in kimchi LAB could be improved significantly by use of efficient expression vectors.

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.271-279
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• 2021

Sweet pumpkin is rich in minerals such as calcium, phosphorus and fiber, and also contains a large amount of β-carotene, which has antioxidant effects. In this study, Makgeolli containing steaming sweet pumpkin (SP) was manufactured to enhance the antioxidant activity. To prepare the Makgeolli, SP was added in amounts of 5, 10, 20, and 30% (w/w), and the chemical (pH, total acidity, alcohol), microbiological (lactic acid bacteria, yeast) properties, and antioxidant activities (DPPH, ABTS) were examined during fermentation and storage for 9 days. The pH of SP Makgeolli was 4.00-4.23 at day 1 of fermentation, and then the pH gradually decreased as fermentation progressed, showing the lowest results at day 9 (3.28-3.52). At day 1, the total acidity was significantly increased (P<0.05) as the amount of SP (0-30%; 0.09-0.55%) and the total acidity in SP Makgeolli (1.01-1.20) was also rapidly increased by 5 days of fermentation. Alcohol content was significantly increased (P<0.05) as the amount of SP (0-30%; 4.59-5.77%) increased at day 9. The counts of lactic acid bacteria and yeast in SP Makgeolli were 8.0-8.1 and 7.9-7.8.0 CFU/mL, respectively, which was higher than SP 0% at day 9. DPPH and ABTS radical scavenging activities were significantly increased (P<0.05) as the amount of SP (0-30%; 48.29-78.97% for DPPH, 62.12-86.68% for ABTS) increased at day 9. This study suggests that Makgeolli added with SP could be potentially and commercially developed due to its superior microbiological and chemical properties, including high antioxidant activities.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.249-255
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• 2004

Chinese cabbage ('Baechu') Kimchi was fermented at the three different temperatures right after it was prepared. Samples were taken everyday for measuring bacterial populations, pH, and titratable acidity through the whole periods of fermentation up to 50 days. pH values and developed acidity were significantly affected by the fermenting temperatures of 4, 10, and $20^{\circ}C$, suggesting that different bacterial flora has been established by the temperatures exposed. The modified MRS agar containing vancomycin (300 $\mu$g/mL) was used for isolating the vancomycin-resistant LAB strains and 127 isolates were finally obtained. Of the LAB isolates, 13 isolates were subjected to the identification experiments based on the biochemical characteristics and the molecular-typing approach, an ITS-PCR, whether they belong to the genus Leuconostoc or not. The data obtained from API 50 CHL kit resulted that six isolates were identified as the members of Leuconostoc and six as Lactobacillus brevis strains except for a single isolate YKI 30-0401, which was not able to be identified because its biochemical traits were not matched to the database of API 50 CHL kit. It was noted that some isolates were distinct in a couple of some biochemical characteristics compared with those of the reference Leuconostoc species. To overcome the limitations experienced in the commercial identification products above, an ITS-PCR experiment was also conducted for the isolates, resulting that eight isolates belong to Leu. mesenteroides ssp. mesenteroides or dextranicum with a single band of 564 bp, and four to L. brevis strains. The ITS-PCR profiles clearly differentiated the closely-related LAB isolates for which same results were obtained by the biochemical method. This molecular approach, however, failed to produce the amplicons for the YKI 20-1003, leaving the strain unidentified. Judging from the identification data obtained in the Kimchi fermented at $4^{\circ}C$ or $10^{\circ}C$, Leuconostoc spp. including Leu. mesenteroides/dextranicum were likely predominant species in the earlier stage and L. brevis occurred at the high level through the whole period. By contrast, L. brevis, as one of the major flora, possibly lead the fermentation from the beginning in the Kimchi fermented at $20^{\circ}C$.}C$.

• Journal of the Korean Society of Food Culture
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• v.20 no.6
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• pp.709-714
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• 2005

Antibacterial activities of the freeze-dried bamboo sap dissolved into the water or 50% ethanol were determined and antimicrobial activity of bamboo sap dissolved into distilled water was most strong with 15 mm of the diameter of inhibiting clear zone against Listeria monocytogenes ATCC 19114 among gram positive bacteria tested, but it did not inhibit Bacillus subtilis ATCC 6633 at all, and the sap was most greatly inhibited the growth of Shigella dysenteriae ATCC 9361 among gram negative bacteria with 15 mm of the diameter of inhibiting clear zone. Bamboo sap dissolved into 50% ethanol most strongly inhibited the growth of L. monocytogenes ATCC 19114 and it also inhibited the growth of B. subtilis ATCC 6633 which did not show any with the sap dissolved into distilled water. The sap dissolved into 50% ethanol was most greatly inhibited the growth of S. dysenteriae ATCC 9361 among gram negative bacteria with 23 mm of the diameter of inhibiting clear zone, and it inhibited Vibrio parahaemolyticus WSDH 22, Vibrio vulnilicus ATCC 29307 and Escherichia coli O157 WSDH 54 with 16 mm of the diameter of inhibiting clear zone. However, Both of the saps dissolved in distilled water and 50% ethanol did not showed any inhibition against the lactic acid bacteria of Lactobacillus plantarum KCTC and Lactobacillus brevis KCTC. Most of the tested bacteria were more sensitive to the sap dissolved in 50% ethanol than the sap dissolved in distilled water. The lowest minimum inhibitory concentration of the bamboo sap dissolved into 50% ethanol was 0.6 mg eq./disc with L. monocytogenes ATCC 19114, but that of the sap dissolved into distilled water was 0.8 mg eq./disc with Staphylococcus epidermides ATCC 12228, S. dysenteriae ATCC 9361, L. monocytogenes ATCC 19114, Salmonella typhimurium WSU 2380 and V. parahaemolyticus WSDH 22. In a model food system of the sterilized chocolate milk, antibacterial activities of the sap dissolved into 50% ethanol were relatively stronger than those of the sap dissolved into distilled water and the activities against the bacteria tested were very similar each other. These result suggested the bamboo sap can be used as a natural food preservative.