• KSBB Journal
• /
• v.30 no.1
• /
• pp.33-37
• /
• 2015

Recently, several health benefits of rice wine, makgeolli, were known due to the interest on the traditional Korean liquor and the researches on the rice wine are increasing. Organic acids produced during the process of rice wine fermentation play important roles in the taste and flavor. In this study, we have examined the optimal conditions for lactic acid production in rice koji as a carbon source. Skim milk was also used as a supplementary ingredient for the optimization of lactic acid fermentation. Bacterial growth of Lactobacillus sakei was monitored under this condition. The pH, acidity of the culture and the ethanol tolerance of this bacterium were also tested. Through these experiments, we were able to optimize the growth condition of lactic acid bacteria by the addition of skim milk. This was also able to affect the change of pH, acidity, sugar concentration and alcohol tolerance, which might contribute to the improvement of the quality of rice wine. The optimal condition for the growth was 2 days with 10% (w/v) of skim milk concentration. With these results, it was confirmed that rice koji was an effective carbon source for the growth of lactic acid bacteria.

• Korean journal of food and cookery science
• /
• v.30 no.4
• /
• pp.480-485
• /
• 2014

Brown rice contains both excellent nutritional value and functional advantages. However, its utilization is limited due to its rough texture and higher concentrations of phytic acid compared to white rice. We made brown rice inoculated with Lactobacillus sakei Wikim001 having phytate activity for 12 h (BRWK-12) and 24 h(BRWK-24) at $30^{\circ}C$ and evaluated the quality characteristics in an attempt to solve these problems. The pH of brown rice inoculated with L. sakei Wikim001 was reduced time dependently. A concentration of phytic acid in brown rice inoculated with L. sakei Wikim001 was decreased as compared normal brown rice (BR). BRWK-24 showed significantly high values in the brightness, redness and yellowness (p<0.05). BRWK-24 received higher scores in texture and overall acceptability than those of BR on the sensory evaluation test. Taken together, it is expected that a treatment of L. sakei Wikim001 in brown rice is useful for the development of new fermented brown rice with reduced phytic acid.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.12
• /
• pp.1617-1621
• /
• 2007

The 21 Kimchi samples collected by a contest for the best Kimchi homemaker in Jeonju were analysed to find major microbial composition and the correlation between sensory scores and the microbial properties, which include total microbial numbers, dominant strain number, subdominant strain number, yeast strain numbers, and floral diversity. The most common microbial composition of the Kimchi samples was Leuconostoc mesenteroides as dominant strain, and Lactobacillus sakei as subdominant strain, the pattern of which was also observed in all three Kimchi samples with the highest sensory scores, but not in all three Kimchi samples with the lowest sensory scores. However none of the other examined properties showed any significant correlation to sensory scores. This result means that the taste of fermented Kimchi depends mainly on the composition of bacterial species and that of Leuconostoc mesenteroides as dominant strain and Lactobacillus sakei as subdominant strain is the best for good taste. Yeast strains were found in the range of $3.8{\sim}4.6log\;CFU/g$ from 8 Kimchi samples and all the strains were identified to be Saccharomyces servazzii. However, fungi were not detected from any of the Kimchi. samples.

• Mycobiology
• /
• v.33 no.4
• /
• pp.210-214
• /
• 2005

More than 120 isolates of lactic acid bacteria obtained from Kimchi was screened for antifungal activity against Aspergillus fumigatus. Approximately 10% of the isolates showed inhibitory activity and only 4.16% (five isolates) exhibited strong activity against the indicator fungus A. fumigatus. The five isolates showed a wide rang of antifungal activity against A. flavus, Fusarium moniliforme, Penicillium commune, and Rhizopus oryzae. They were identified by 16S rDNA sequencing as Lactobacillus cruvatus, L. lactis subsp. lactis, L. casei, L. pentosus, and L. sakei. The effect of Lactobacillus on mycelial growth and fungal biomass as well as its ability to produce toxic compounds were determined. The results indicate that the three species, Lactobacillus casei, L. lactis subsp. lactis, and L. pentosus, are active against A. fumigatus.

• Animal Bioscience
• /
• v.36 no.5
• /
• pp.797-809
• /
• 2023

Objective: Many scientists have investigated solutions to reduce microbiological risks in dry-aged meat after the dry-aging technology was revived for high quality and value-added premium meat product in the market. This study aimed to investigate the effect of scoria powder in onggi (Korean earthenware) on the meat quality of pork loins during 21 days of dry aging and to elucidate its mechanism of action. Methods: The pork loins were randomly divided into three groups: aged in vacuum-packaging, onggi containing red clay only (OR), and onggi containing 30% red clay and 70% scoria powder (OS). Microbial analyses (total plate count and Lactobacillus spp.) and physicochemical analyses (pH, shear force, volatile basic nitrogen [VBN], water activity, 2-thiobarbituric acid reactive substances, water content, water holding capacity, cooking loss, and color analysis) of aged meat were conducted. Far-infrared ray emission, quantification of immobilized L. sakei and microstructure of onggi were investigated to understand the mechanism. Results: On day 21, the meat aged in OS exhibited lower pH, shear force, VBN, and water activity than those aged in OR, along with an increase in the number of Lactobacillus spp. OS had a smaller pore diameter than OR, implying lower gas permeability, which could promote the growth of L. sakei. Conclusion: OS improved the microbiological safety and storage stability of pork loin during dry aging by increasing number of Lactobacillus spp. possibly due to low permeability of OS.

• Korean Journal of Microbiology
• /
• v.50 no.1
• /
• pp.73-83
• /
• 2014

The objective of the this study was to investigate the binding capacity and removal ability of lactic acid bacterial strains obtained from Korean soybean paste for mutagenic heterocyclic amines (HCAs) formed during cooking of protein-rich food at high temperature. Among 19 strains identified by carbohydrate fermentation and 16S rRNA sequencing, the live cell or cell-free culture supernatant of Lactobacillus acidophilus D11, Enterococcus faecium D12, Pediococcus acidilactici D19, L. acidophilus D38, Lactobacillus sakei D44, Enterococcus faecalis D66, and Lactobacillus plantarum D70 inhibited the mutagenesis caused by either 3-amino-1,4-dimethyl-5H-pyrido[4,3-b] indole (Trp-P-1) or 3-amino-1-methyl-5H-pyrido[4,3-b] indole (Trp-P-2) in Salmonella typhimurium TA98 and TA100. The bacterial cells of the isolated strains showed greater binding activity than the pure cell wall, exopolysaccharide, and pepetidoglycan. The carbohydrate moieties of the cell wall or protein molecules on the cell surface have a significant role in binding Trp-P-1 and Trp-P-2, since protease, heating, sodium metaperiodate, or acidic pH treatments significantly (P<0.05) reduced the binding efficacy of the tested bacteria. Addition of metal ions or sodium dodecyl sulfate decreased the binding ability of E. faecium D12, L. acidophilus D38, and E. faecalis D66. Therefore, the binding mechanisms of these strains may consist of ion-exchange and hydrophobic bonds. Especially, the high mutagen binding by L. acidophilus D38 and L. plantarum D70 may reduce the accumulation or absorption of Trp-P-1 and Trp-P-2 in the small intestine via increased excretion of a mutagen-bacteria complex.

• Korean Journal of Microbiology
• /
• v.54 no.2
• /
• pp.113-125
• /
• 2018

Purpose of the present study was to investigate the factors affecting the production of antibacterial substances and histamine in rennet curd prepared by inoculation of histamine-producing lactic acid bacteria (LAB) and probiotic LAB. Probiotic Lactobacillus sakei PIL52 and Lactobacillus plantarum FIL20 produced strong antimicrobial agents against histamine-producing bacteria Lactobacillus brevis LAS129, Enterococcus faecium SBP12, and Enterococcus faecalis SBP58. The lactic acid and crude bacteriocin produced from the probiotic LAB inhibited histamine-producing bacteria in a concentration-dependent manner. As the number of probiotic LAB inoculated for the production of rennet curd increased, the antibacterial activity against histamine-producing bacteria was elevated due to the increased amount of lactic acid and crude bacteriocin in the sample. The growth of probiotic LAB as well as histamine-producing bacteria was inhibited by addition of 10% NaCl, thus the antibacterial substances and histamine contents in rennet curd were significantly lower than those of the control (P < 0.05). Meanwhile, the histamine content was not significantly increased when the rennet curd prepared by mixing probiotic LAB and histamine-producing bacteria was stored at $25^{\circ}C$ for 5 days. However, the amount of histamine detected in the rennet curd was significantly (P < 0.05) increased because the antibacterial activity of the bacteriocin produced by the probiotic LAB was decreased at $20^{\circ}C$ for 20 days.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.5
• /
• pp.671-675
• /
• 2008

Based on information about the major microbial composition of kimchi and its relation to the taste, Leuconostoc mesenteroides K2M5 and Lactobacillus sakei K5M3 were selected as kimchi starter candidates. These two strains were found to be safe for industrial use because they showed neither harmful characteristics like ${\beta}$-hemolysis, ammonia and indole formation, and gelatin liquefaction, nor enzymatic activities like phenylalanine deaminase, ${\beta}$-glucuronidase, ${\beta}$-glucosidase, 7${\alpha}$-dehydroxylase and nitroreductase. Starter kimchi made with these strains were better in taste than the conventional kimchi when they are evaluated both by laboratory personnel and the public. Also microbial analysis of starter kimchi showed only starter bacteria after they were fermented to have the optimum acidity. Starter kimchi prepared with these two strains were not much different in physicochemical properties to the conventional kimchi except in that the starter kimchi were much higher in volatile organic acid content such as lactic acid. These results suggest that kimchi quality can be controlled to have consistent properties, both in taste and microbial composition, by using bacterial starters.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.7
• /
• pp.1084-1089
• /
• 2015

To develop high quality citrus products, seven lactic acid bacteria were innoculated onto ground citrus (Citrus unshiu) and cultured for 10 days. On culture days 0, 3, 5, 7, and 10, citrus ferments were withdrawn, and their antimicrobial and angiotensin-I converting enzyme (ACE) inhibitory activities were evaluated. Citrus ferments innoculated with CL-1 and CL-2, which were isolated from kimchi, showed relatively higher antimicrobial activities against food poisoning bacteria. Citrus ferments innoculated with CL-1 and CL-2 also showed stronger ACE inhibitory activities than other ferments. CL-1 and CL-2 showed more than 99% homogeny with Pediococcus acidilactici and Lactobacillus sakei, respectively, by 16S rRNA gene analysis. These results indicate that fermentation with P. acidilactici and L. sakei might contribute to the increased antimicrobial and anti-hypertensive activities of citrus.

• Microbiology and Biotechnology Letters
• /
• v.31 no.2
• /
• pp.129-134
• /
• 2003

The purpose of the present study was to screen the effective of lactic acid bacteria (LAB) as probiotics, which are able to protect aquacultural fish pathogenic bacteria, and investigate their characterization. Twenty strains of lactic acid bacteria were isolated from fish intestine, fermented fish foods and kimchis. These bacteria were screened for antagonistic activity against fish pathogenic bacteria. Seven tested LAB strains were able to inhibit the fish pathogenic bacteria, including Vibrio anguillarum, Edwardsiella tarda, and Streptococcus sp.. Of the probiotic candidates, BK19 strain isolated from fermented pollack viscera indicated the largest inhibition activity. Moreover, this strain showed a resistance over low pH and antibiotic agents. Therefore this probiotic candidate BK19 was finally selected and identified as a probiotic strain. This particular probiotic bacteria was identified as Lactobacillus sakei BK19 by biochemical characteristics and 165 rRNA PCR amplification.