• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.218-221
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• 2004

Irradiated red pepper powder (IRPP) was tested for its ability to retard fermentation and to maintain a high quality of Kimchi by the reduction of the initial microbial load. Kimchi containing IRPP at the doses of 0, 5, 10, 15, or 20 kGy was prepared. Quality indices for Kimchi in this study were pH, titratable acidity, reducing sugar content, total microbial count, lactic acid bacterial load, and sensory evaluation. Based on the pH and titratable acidity, the Kimchi with IRPP showed a retarded fermentation until 15 days. The number of the total aerobes and lactic acid bacteria of the Kimchi with IRPP were lower by about 1 log CFU/mL compared to control at day 0, however, the counts increased to 8.5 log CFU/mL after 10 days, which was similar to the control group. Kimchi that was fermented with 5 kGy IRPP was better than control and other treatments in odor and color, whereas the control scored highest in taste. Addition of IRPP showed a limited retardation of Kimchi fermentation without other quality deterioration.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1680-1685
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• 2003

Antimutagenicity of milk cultured with lactic acid bacteria isolated from dadih on the mutagenicity of heated salty and sweet tauco was examined using streptomycin dependent (SD) 510 strain of Salmonella typhimurium TA 98 as a tester culture. Cultured milk samples exhibited widely antimutagenic activity against mutagenic heated salty and sweet tauco. Lc. lactis subsp. lactis R-22, Lc. lactis subsp. casei R-35, Lc. lactis subsp. casei R-52 and E. faecalis subsp. liquefaciens R-55 exhibited no inhibitory effect on the mutagenic heated salty tauco. Mutagenicity of heated sweet tauco was inhibited by cultured milks stronger than that of heated salty tauco. Milk cultured with Lc. lactis subsp. cremoris R-48, Leuc. mesentroides R-51 and Lc. lactis subsp. casei R-68 showed high inhibition against the mutagenicity of both heated salty and sweet taucos. Antimutagenic activity of the cultured milks against mutagenic heated tauco was attributed to the bacterial cells. Among the three strains which showed high antimutagenicity, only Leuc. mesentroides R-51 was tolerant to both acid and bile; so this strain can be used as probiotic in preventing the occurrence of mutagenesis caused by mutagenic heated food like tauco.

• Korean Journal of Veterinary Service
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• v.22 no.4
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• pp.411-418
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• 1999

In this studies, the ability of chlorine and lactic acid to reduce bacterial population of the pathogenic microorganisms were examined on artificially inoculated chicken skin. About 10$^{5}$ cells of staphylococcus aureus, salmonella enteritidis, listeria monocytogenes and escherichia coli O157:H7 were inoculated in chicken skin. The contaminated samples were washed for 1 min with sodium hypochlorite solutions that contained 2, 5, 10, 20 and 50mg/$\ell$ available chlorine and counted number of the agents. Viable population were no significantly difference (p$\geq$0.05) between concentration of chlorine and strains of the pathogens. In the samples inoculated with pathogens were washed in 20mg/$\ell$ chlorine and then stored at $^5{\circ}C$ for up to 10 days, the initial counts of psychrotrophs and aerobic plate counts were 4.02 to 4.36 log cfu/$\textrm{cm}^2$ and increased slightly in course of time. But 10 days after, the pathogens were a little reduced from 3.66~4.91 log cfu/$\textrm{cm}^2$ to 2.54~4.66 log cfu/$\textrm{cm}^2$. In the case of washed skin with solution of 20mg/$\ell$ chlorine and 0.5% lactic acid then store at $^5{\circ}C$ for up to 10 days, population of psychrotrophs and aerobic plate counts on chicken skin were markedly reduced immediately after treatment, but the numbers of contaminants were slightly increased after 6 and 8 days. Specifically, numbers of St aureus, S enteritidis, L monocytogenes and E coli O157:H7 were reduced to 0.5, 0.4, 0.3 and 1.15 log cfu/$\textrm{cm}^2$ after 10 days of storage, respectively, on aerobic plate counts.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.365-365
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• 2017

Yogurt is a food produced by bacterial fermentation of milk and the bacteria used to make it are known as "yogurt cultures". Most of them belong to probiotics such as Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus bacteria. Domestic fermented milk market is increasing and about 30 companies are producing yogurt. The purpose of this study was to analyze the quality characteristics of domestic commercial semisolid type yogurt. We collected 20 types of commercial yogurt at local markets. Physicochemical properties including pH, sugar content, acidity, viscosity and microbial characteristics of lactic acid bacteria counts were measured. The yogurt showed pH 4.5, 7.4~18.1% of sugar contents, 0.6~1.3% of total acids and 282~748 cP of viscosities. In the microorganism populations, lactic acid bacteria count were 6.5~11.5 Log CFU/mL and anaerobic lactic acid bacteria count were 7.2 ~ 11.1 Log CFU/mL. The quality characteristics were different depending on the constituents of the sample and the microorganisms used. These results are related to the quality characteristics of yogurts which are useful information about identifying new trends in domestic fermented milk industry.

• Korean journal of food and cookery science
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• v.17 no.3
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• pp.211-217
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• 2001

The objective of this study was to evaluate the effect of functional herbal foods on the growth of intestinal lactic acid bacteria. When Bifidobacterium breve and human intestinal microflora were inoculated in the general anaerobic medium which contained each functional food water extract, most of functional herbal foods induced the growth of lactic acid bacteria by decreasing pH of the broth. The pH decreasing effects of Liriipe platyphylla and Platycodon grandiflorum were excellent. The growth of lactic acid bacteria effectively inhibited the bacterial enzymes, $\beta$-glucosidase and $\beta$ -glucuronidase. Eugenia caryophyllata and Liriipe platyphylla potently inhibited the productivity of P -glucosidase of B. breve and human intestinal bacteria. Cinnamomum cassia, Gardenia jasminoides and Platycodon grandiflorum potently inhibited the productivity of $\beta$-glucuronidase of human intestinal bacteria. The growth component isolated from Platycodon grandiflorum was sucrose (compound B).

• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.10-17
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• 2023

Dairy products are extensively used as carriers of probiotic strains that have potential health benefits. Assessment of the viability of probiotic strains during manufacturing is important to ensure that products meet recommended levels. Hence, the method for accurately quantifying lactic acid bacteria (LAB) in probiotic or dairy products is required. The present study aims to examine the performance of de-Man Rogosa Sharpe (MRS), plate count agar with bromocresol purple (PCA with BCP), and glucose blood liver (BL) agars recommended in the Korea Food Code guidelines for counting LAB. Analysis of the performance of culture media containing 19 lactic acid bacterial species commonly encountered in probiotic and dairy products showed no statistically significant difference between 18 reference strains and three culture media (p > 0.01). Furthermore, the suitability of three culture media was verified for the quantitative assessment of LAB in 25 probiotic and dairy products. The number of LAB in three culture media was determined to be more than 10⁷ colony-forming unit (CFU)/ml for fermented milk products and 10⁸ CFU/ml for condensed fermented milk and probiotic products, indicating that they all satisfied the Korea Food Code guidelines. Moreover, there was no statistically significant difference in the amount of LAB counted in all three culture media, suggesting that they can be used to isolate or enumerate LAB in commercial products. Finally, three culture media will be useful for isolating and enumerating LAB from fermented foods as well as gut microflora.

• Journal of Dairy Science and Biotechnology
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• v.25 no.1
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• pp.15-20
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• 2007

Effects of gamma irradiation on chemical, microbiological, and immunological changes of Queso Blanco cheese were investigated. Although Queso Blanco cheese was made by heat pasteurization at 85$^{\circ}$C and addition of acid without lactic starter culture, total bacterial counts and lactic acid bacterial counts of control cheese were 7.65${\pm}$0.04 and 7.64${\pm}$0.02 log CFU/mL, respectively. It was thought that this microbial growth was due to the incomplete inactivation of raw milk by the heat treatment, resulting into growth during the pressing and the drying process. It demonstrated the possibility that if heat- and acid-resistant hazard microbes are present in raw milk, they can grow during the processes. Lactic acid bacterial counts of the irradiated cheese were 5.45${\pm}$0.02 log CFU/mL at 1kGy, 2.12${\pm}$0.12 log CFU/mL at 2kGy, and not detected at 3kGy or higher doses. The reduction of antigenicity by gamma irradiation was not found. It might be caused by the fact that most whey proteins of milk, a major antigen in milk, were already denaturated by heat process and removed during the draining.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.332-336
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• 2017

This study was conducted to investigate the effect of addition of lactic acid bacteria inoculants on quality of rye silage harvested at early heading stage. The nutritive values in lactic acid bacteria (LAB) inoculated group showed similar results to control. The pH of rye silage in LAB inoculation significantly decreased as compared to control (p<0.05). In addition, the content of lactic acid in LAB inoculation significantly increased (p<0.05), but the content of acetic acid in LAB treatments decreased. In addition, lactic acid bacterial counts in LAB inoculation significantly increased as compared to control (p<0.05). Therefore, we suggest that rye silage could be improved by LAB inoculation.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.220-233
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• 2019

Bacterial lysates have become a common ingredient for natural health care. Lactic acid bacteria (LAB) could serve as potential candidates for lysate production: the lactic acids produced by LAB have been utilized for their moisturizing, antimicrobial, and rejuvenating effects, while other substances provide topical benefits and health effects for the skin. Our study aimed to obtain lysate from a LAB S. macedonicus MBF 10-2 through an optimized fermentation using the Response Surface Methodology. Strain MBF10-2 was cultivated in a 2L fermenter tank in de Man Rogosa and Sharpe (MRS) medium and in plant-based peptone modified MRS, i.e. Soy-peptone and Vegitone. The duration and the medium composition (dextrose and soy peptone or proteose peptone) were adjusted to obtain an optimum production of cell lysate. Central Composite Design was employed for Design Expert 7.0.0 by adjusting 3 factors: dextrose (1%, 1.5%, 2%, 2.5%, 3%), soy or proteose peptone (0.5%, 0.75%, 1%, 1.25% and 1.5%), and duration of fermentation (8, 10, 12 14, and 16 h for MRS-Soy peptone and 15, 17, 19, 21, and 23 h for MRS Vegitone). Bacteriocin-Like Inhibitor Substance activity of lysate and pH were used as indicators. The optimum condition for lysate production using MRS Soy Peptone and Vegitone are as follows: dextrose concentration 2.5%, plant-based peptone 1.25%, while optimum fermentation duration were 11.18 h (MRS Soy Peptone) and 17 h (MRS Vegitone) with a starter concentration of 10% at $OD_{600nm}$ $0.2{\pm}0.05$. However, the standard MRS medium produced better quality lysate compared to MRS plant-based peptones.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.12
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• pp.1873-1881
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• 2019

Objective: Information regarding the vitamin content of silage is limited. This study investigated the changes in the vitamin content of alfalfa and Chinese leymus silages with or without a lactic acid bacterial inoculant. Methods: Alfalfa at the early flowering stage and Chinese leymus at the full-bloom stage were harvested. The treatments for each forage type were control (deionized water only) and $1{\times}10^6$ colony-forming units Lactobacillus plantarum (LP)/g fresh matter. After 45 days of ensiling, all silages were sampled for evaluating the vitamin content, fermentation quality and chemical composition. Results: The LP inoculant decreased the pH value and ammonia nitrogen content of the alfalfa and Chinese leymus silages and significantly (p<0.05) increased the lactic acid, acetic acid concentrations and Flieg's points. Prior to ensiling, the levels of five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, and pyridoxine) and ${\alpha}$-tocopherol in alfalfa were significantly (p<0.01) higher than those in Chinese leymus. Ensiling decreased the levels of the five B-group vitamins in both alfalfa and Chinese leymus while increasing the ${\alpha}$-tocopherol content of Chinese leymus. The thiamin, riboflavin, niacin and pantothenic acid levels in the LP-treated silage were significantly (p<0.05) lower than those in the untreated silage for the alfalfa and Chinese leymus. The ${\alpha}$-tocopherol content in the LP-treated alfalfa silage was significantly (p<0.05) higher than that in the untreated alfalfa silage. There was no significant (p>0.05) difference in pyridoxine content between the untreated and LP-treated silages for both forages. Conclusion: With or without LP inoculation, the levels of the five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, and pyridoxine) in alfalfa and Chinese leymus decreased after 45 days of ensiling, while the ${\alpha}$-tocopherol content of Chinese leymus increased. The LP inoculant improved the fermentation quality of both the alfalfa and Chinese leymus silages but increased the thiamin, riboflavin, niacin, and pantothenic acid loss in the two forages after fermentation.