• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1115-1119
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• 1999

Chitosan was used to treat lavers during the production of dried lavers. In the procedure of washing the harvested lavers, the lavers were treated with various solutions of 0.1 and 0.01% of 30 cp chitosan and of 0.005 and 0.04% of 90 cp chitosan. Then treated lavers were processed as usual for the production of dried lavers. Significant differences between chitosan-treated and non-treated lavers were observed in flavor, in total microbial counts, and in the number of coliform microorganisms. Off-flavor of dried lavers was reduced significantly by treating with chitosan. Total microbial count was $3.7{\times}10^{4}$ cells/g in the non-treated dried lavers, but they were $5.7{\times}10^{3}$ cells/g and $2.1{\times}10^{3}$ cells/g, respectively, in the dried lavers treated with 0.01% and 0.1% of 30 cp chitosan. The number of coliform microorganisms was 240 cells/g in non-treated dried lavers. However, coliform microorganisms were not detected in the dried lavers treated with 0.1% of 30 cp chitosan. When the dried lavers were used to make Kimbab (rice rolled with laver), the number of total microorganisms increased very slowly during storage time at $20^{\circ}C$ in the Kimbab rolled with chitosan-treated dried lavers compared to that in the Kimbab rolled with non-treated dried lavers.

• Animal cells and systems
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• v.3 no.2
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• pp.153-159
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• 1999

In an artificial pH-gradient batch culture system, the effects of acidification on the species composition of a heterotrophic bacterial community were analyzed. As a result of this study, it was found that total bacteria numbers were not affected by acidification and that the population of hetero-trophic bacteria decreased as pH became lower. The heterotrophic bacteria isolated from the entire pH gradient were 12 genera and 22 species. Among them, 64% were gram negative and 36% were gram positive bacteria. As pH decreased, the distribution rate of gram negative bacteria increased while that of gram positive bacteria decreased. The diversity of genera decreased from 13 to 5 as pH decreased from 7 to 3. The G+C content of all of the 202 isolated strains varied from 22.8 to 77.0%, and increased in interspecies of same genus as pH decreased. As a result of clustering analysis, the diversity index of species ranged from 1.13 to 2.37, and it had lower indices as pH decreased. In order to evaluate the diversity of numbers of sample of different size, a rarefaction method was used to analyze the expected number of species appearance according to pH. The statistical significance of species diversity was verified by the fact that the number decreased at lower pH.

• Preventive Nutrition and Food Science
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• v.12 no.3
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• pp.167-172
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• 2007

This study was conducted to determine the effect of hygienic processing (HP) on the reduction of microorganisms during manufacturing of saengshik with two vegetables (carrots and cabbage) and two grains (barely and glutinous rice) compared to general processing (GP). For GP, distilled water was used for washing raw materials and equipment. For HP, aqueous ozone (3 ppm) in combination with 1% citric acid and 70% alcohol were used for washing raw materials and the equipment, respectively. In carrots, after cutting, total aerobic bacteria (TAB), yeast and mold (YM) and coliforms were significantly increased to 5.19, 8.04 and 2.08 ($log_{10}$ CFU/g), respectively (p<0.05). Washing effectively reduced the increased microorganisms from cross contamination during cutting, but cross contamination increased with subsequent GP drying and milling procedures to 8.56, 8.27 and 3.71 ($log_{10}$ CFU/g) for TAB, YM and coliforms, respectively (p<0.05). On the other hand, HP washing of carrots with 3 ppm ozone in combination with 1% citric acid showed higher antimicrobial effect than GP washing, significantly decreasing the number of microorganisms (p<0.05). Further cross contamination did not occur through drying and milling due to cleaning the equipments with 70% alcohol prior to processing. After milling, the number of TAB, YM and coliforms were significantly decreased to 3.89, 4.47 and not detectable level ($log_{10}$ CFU/g), respectively (p<0.05). Similar results were observed in cabbage and grains. During storage for two months at different temperatures (22 or $4^{\circ}C$), there were no changes in numbers of spoilage microorganisms in the packaged saengsik after either processing. This suggests the importance of HP for the reduction of microorganisms during saengsik production, and demonstrates the effectiveness of disinfection at each processing stage in minimizing contamination levels to enhance microbial safety of saengshik products.

• Journal of Food Hygiene and Safety
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• v.15 no.1
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• pp.25-29
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• 2000

General composition and microbial load of brine recycled to 6 times for Chinese cabbage salting and the quality of Kimchi using every brined cabbage were investigated. The concentration of salt(NaCl) in brine after soaking dropped 1.35-2.49% and pH of the brine changed significantly until 4 times recycling. The acidities were increased as number of recycling increased. The total viable cell count in recycled brine increased from 1.58$\times$10$^{6}$ /mL in the first soaking brine to 2.3$\times$10$^{9}$ /mL in 4th soaking brine which was highest in number. The pure soluble solid and vitamin C content in brine were accumulated to 0.93% and 0.55 mg% respectively after 6th recycling. The pH, acidity and sensory evaluation results of Kimchi prepared by Chinese cabbage salted by each brine recycled 6 times showed no significant difference. It means there is a possiblity reusing brine for salting of cabbage for the preparation of Kimchi to 6 times.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.216-221
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• 2007

Microbiological, chemical and sensorial quality changes of kimchi, which was manufactured with sanitized materials by ozone and gamma irradiation, were investigated during storage. The number of total aerobic bacteria in control was increased rapidly by storage and decreased after 10 days of storage. However, the kimchi which was manufactured with materials treated with ozone or gamma irradiation showed a lower rate of increase. The number of lactic acid bacteria was lower in control than in treatments. Gamma irradiation of 3 or 5 kGy showed the lowest change of microbial population in kimchi during storage. pH, acidity and sensory quality were also rapidly changed in control whereas those of ozone or irradiation treated sample was slower. Therefore, cold pasteurization of materials before kimchi manufacturing provide a slower fermentation, resulting into the extension of storage quality for kimchi.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.193-203
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• 1998

20 Subjects with clinical diagnosis of adult periodontitis with sites having average pocket depth of 4mm were selected for the study. After scaling and root planing of those sites, 30% minocycline-HCI contained in biodegradable device were inserted in one group, scaling and root planing was carried out in another group and the last group was without any periodontal treatment. the difference between the group was detemined by pocket dept, bleeding on prbing, attachment level, distribution of subgingval plaque bacteria. Conclusion was made for the comparisons between baseline and 4 week and the groups. 1. In analysis of pocket depth, there was significant sifference in scaling and root planing group only. 2. Both the scaling and root planing group and minocycline group showed significant decrease in bleeding on probing. 3. There was significant increase in the attachment level in scaling and root planing group, but no difference was foundbetween the groups. 4. There was significant decrease in the total number of subgingival bacteria in all groups and the number of motile bacteria decreased significantly in the minocycline group. These result indicate that insertion of Minocycline-HCI at the base of periodntal pocket was useful as an additional aid of mechanical trarment at the point of periodontal pocket, bleeding on probing, attachment level, microbial distribution.

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

• Food Science of Animal Resources
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• v.40 no.4
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• pp.541-550
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• 2020

The use of yeast assist kefir fermentation, but also can cause food spoilage if uncontrolled. Hence, in this study, the microbial composition of an existing commercial kefir starter was modified to produce a functional starter, where Lactobacillus acidophilus KCNU and Lactobacillus brevis Bmb6 were used to replace yeast in the original starter to produce non-yeast kefir-like fermented milk. The functional starter containing L. acidophilus KCNU and L. brevis Bmb6 demonstrated excellent stability with 10¹⁰ CFU/g of total viable cells throughout the 12 weeks low-temperature storage. The newly developed functional starter also displayed a similar fermentation efficacy as the yeast-containing control starter, by completing the milk fermentation within 12 h, with a comparable total number of viable cells (10⁸ CFU/mL) in the final products, as in control. Sensory evaluation revealed that the functional starter-fermented milk highly resembled the flavor of the control kefir, with enhanced sourness. Furthermore, oral administration of functional starter-fermented milk significantly improved the disease activity index score by preventing drastic weight-loss and further deterioration of disease symptoms in DSS-induced mice. Altogether, L. acidophilus KCNU and L. brevis Bmb6 have successfully replaced yeast in a commercial starter pack to produce a kefir-like fermented milk beverage with additional health benefits. The outcome of this study provides an insight that the specific role of yeast in the fermentation process could be replaced with suitable probiotic candidates.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1347-1356
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• 2013

Tricholoma matsutake, an ectomycorrhiza that has mutual relationships with the rootlet of Pinus denisflora, forms a fruiting body that serves as a valuable food in Asia. However, the artificial culture of this fungus has not been successful. Soil fungi, including T. matsutake, coexist with many other microorganisms and plants; therefore, complex microbial communities have an influence on the fruiting body formation of T. matsutake. Here, we report on the structures of fungal communities associated with the fairy ring of T. matsutake through the pyrosequencing method. Soil samples were collected inside the fairy ring zone, in the fairy ring zone, and outside the fairy ring zone. A total of 37,125 sequencing reads were obtained and 728 to 1,962 operational taxonomic units (OTUs) were observed in the sampling zones. The fairy ring zone had the lowest OTUs and the lowest fungal diversity of all sampling zones. The number of OTUs and fungal taxa inside and outside the fairy ring zone was, respectively, about 2 times and 1.5 times higher than the fairy ring. Taxonomic analysis showed that each sampling zone has different fungal communities. In particular, out of 209 genera total, 6 genera in the fairy ring zone, such as Hemimycena, were uniquely present and 31 genera, such as Mycena, Boletopsis, and Repetophragma, were specifically absent. The results of metagenomic analysis based on the pyrosequencing indicate a decrease of fungal communities in the fairy ring zone and changes of fungal communities depending on the fairy ring growth of T. matsutake.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.3
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• pp.292-299
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• 2005

Six kinds of spirulina added dressing $(0\~1.09\%)$ were prepared and their rheological, physical and sensory characteristics were evaluated The hardness and adhesiveness of spirulina-added salad dressing were increased with the added amounts of spirulina. Viscosity of spirulina-added salad dressing was not significantly different up to $0.28\%$ whereas that of dressing added more than $0.55\%$ spirulina significantly increased, compared with that without spirulina. Emulsion stability of all of spirulina-added salad dressings was $40\%$ Antioxidant activities of spirulina-added salad dressing increased with spirulina increased: $IC_{50}$ values of DPPH radical scavenging activity and lipid peroxidation inhibition activity of $0.28\%$ added-dressing were 104.98 mg/mL and $6.71{\mu}g/mL$ of TBARS, respectively, which were higher than those of mayonnaise. The fat globule size of $0.28\%$ spirulina-added salad dressing was distributed within $0.5\~4.0{\mu}m$, of which $85.6\%$ of total fat globules were consisted of the size of less than $1.5\{\mu}m$. Total microbial number of salad dressing was 6.2log(CFU/mL), but E coli was not detected Sensory preference test of spirulina-added salad dressing showed that scores of appearance, flavor, viscosity and over-all preference for $0.28\%$ added-dressing were the highest with 7.83, 7.50, 5.33 and 7.97, respectively. Based on these results, spirulina-added salad dressing might have heath promoting effect showing antioxidant activity, and the most appropriate concentration of spirulina for salad dressing was $0.28\%$.