• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.2
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• pp.121-126
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• 2018

The purpose of this study was to assess bacteriological hazards in the following 7 kinds of minimally processed shellfish products purchased from Korean seafood retail outlets: raw oysters stored with seawater in polyethylene bags, frozen oysters, raw mussels, frozen mussels, boiled mussels, raw short-necked clam, and frozen short-necked clams, obtained from Korean seafood retail outlets. The total coliform and Escherichia coli counts determined in all samples were detected below regulation limit of the Korean government guidelines (Food Code). In addition, the high-risk bacterial pathogens, Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 were not detected in any samples. Low-risk pathogens such as Staphylococcus aureus and Vibrio parahaemolyticus were detected at levels above $1.0{\times}10^2$ colony forming unit (CFU)/g in some minimally processed shellfish products. Notably, S. aureus was detected in all samples. Raw oysters stored with seawater in polyethylene bags, frozen oysters, and boiled blue mussels are commonly ingested without heating, and therefore these minimally processed shellfish products pose bacteriological hazards. The detection of S. aureus in all shellfish products, an organism indicative of poor personal hygiene, which can grow and multiply during distribution, indicates the necessity of improving the food safety of minimally processed shellfish products.

• Clinical and Experimental Pediatrics
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• v.60 no.7
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• pp.221-226
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• 2017

Purpose: Escherichia coli sequence type (ST) 131, a multidrug-resistant clone causing extraintestinal infections, has rapidly become prevalent worldwide. However, the epidemiological and clinical features of pediatric infections are poorly understood. We aimed to explore the characteristics of ST131 Escherichia coli isolated from Korean children with urinary tract infections. Methods: We examined 114 uropathogenic E. coli (UPEC) isolates from children hospitalized at Chung-Ang University Hospital between 2011 and 2014. Bacterial strains were classified into STs by partial sequencing of seven housekeeping genes (adk, fumC, gyrB, icd, mdh, purA, and recA). Clinical characteristics and antimicrobial susceptibility were compared between ST131 and non-ST131 UPEC isolates. Results: Sixteen UPEC isolates (14.0%) were extended-spectrum ${\beta}-lactamase$ (ESBL)-producers; 50.0% of ESBL-producers were ST131 isolates. Of all the isolates tested, 13.2% (15 of 114) were classified as ST131. There were no statistically significant associations between ST131 and age, sex, or clinical characteristics, including fever, white blood cell counts in urine and serum, C-reactive protein, radiologic abnormalities, and clinical outcome. However, ST131 isolates showed significantly lower rates of susceptibility to cefazolin (26.7%), cefotaxime (40.0%), cefepime (40.0%), and ciprofloxacin (53.3%) than non-ST131 isolates (65.7%, 91.9%, 92.9%, and 87.9%, respectively; P<0.001 for all). ESBL was more frequently produced in ST131 (53.3%) than in non-ST131 (8.1%) isolates (P<0.01). Conclusion: ST131 E. coli isolates were prevalent uropathogens in children at a single medical center in Korea between 2011 and 2014. Although ST131 isolates showed higher rates of antimicrobial resistance, clinical presentation and outcomes of patients were similar to those of patients infected with non-ST131 isolates.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.977-983
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• 2009

The survival and effect of three new probiotic inoculants (Lactobacillus plantarum CCM 4000, L. fermentum LF2, and Enterococcus faecium CCM 4231) on the nutritive value and fermentation parameters of corn silage was studied under laboratory conditions. Whole corn plants (288.3 g/kg DM) were cut and ensiled at $21^{\circ}C$ for 105 days. The inoculants were applied at a concentration of $1.0{\times}10^{9}$ cfu/ml. Uninoculated silage was used as the control. The chopped corn was ensiled in 40 plastic jars (1 L) divided into four groups (4${\times}$10 per treatment). All corn silages had a low pH (below 3.55) and 83-85% of total silage acids comprised lactic acid after 105 days of ensiling. The probiotic inoculants in the corn silages affected corn silage characteristics in terms of significantly (p<0.05-0.001) higher pH, numerically lower crude protein content and ratio of lactic to acetic acid compared to control silage. However, the inoculants did not affect the concentration of total silage acids (acetic, propionic, lactic acids) as well as dry matter digestibility (IVDMD) of corn silages in vitro. In the corn silages with three probiotic inoculants, significantly (CCM 4231, CCM 4000) lower n-6/n-3 ratio of fatty acids was detected than in control silage. Significant decrease in the concentration of $C_{18:1}$, and significant increase in the concentration of $C_{18:2}$ and $C_{18:3}$ was mainly found in the corn silages inoculated with the strains E. faecium CCM 4231 and L. plantarum CCM 4000. At the end of ensiling, the inoculants were found at counts of less than 1.0 log10 cfu/g in corn silages.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.11
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• pp.1781-1794
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• 2018

Objective: This meta-analysis was conducted to evaluate the overall effect of direct-fed microbial (DFM) or probiotic supplementation on the log concentrations of culturable gut microbiota in broiler chickens. Methods: Relevant studies were collected from PubMed, SCOPUS, Poultry Science Journal, and Google Scholar. The studies included controlled trials using DFM supplementation in broiler chickens and reporting log concentrations of the culturable gut microbiota. The overall effect of DFM supplementation was determined using standardized mean difference (SMD) with a random-effects model. Subgroups were analyzed to identify pre-specified characteristics possibly associated with the heterogeneity of the results. Risk of bias and publication bias were assessed. Results: Eighteen taxa of the culturable gut microbiota were identified from 42 studies. The overall effect of DFM supplementation on the log concentrations of all 18 taxa did not differ significantly from the controls (SMD = -0.06, 95% confidence interval [-0.16, 0.04], p = 0.228, $I^2=85%$, n = 699 comparisons), but the 18 taxa could be further classified into three categories by the direction of the effect size: taxa whose log concentrations did not differ significantly from the controls (category 1), taxa whose log concentrations increased significantly with DFM supplementation (category 2), and taxa whose log concentrations decreased significantly with DFM supplementation (category 3). Category 1 comprised nine taxa, including total bacterial counts. Category 2 comprised four taxa: Bacillus, Bifidobacterium, Clostridium butyricum, and Lactobacillus. Category 3 comprised five taxa: Clostridium perfringens, coliforms, Escherichia coli, Enterococcus, and Salmonella. Some characteristics identified by the subgroup analysis were associated with result heterogeneity. Most studies, however, were present with unclear risk of bias. Publication bias was also identified. Conclusion: DFM supplementation increased the concentrations of some beneficial bacteria (e.g. Bifidobacterium and Lactobacillus) and decreased those of some detrimental bacteria (e.g. Clostridium perfringens and Salmonella) in the guts of broiler chickens.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.413-417
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• 2003

To evaluate the antimicrobial activity of green tea against putrefactive microorganism in steamed bread, antibacterial activity of green tea extract against well-known strains of spoilage bacteria (Bacillus subtilis ATCC 6633, Bacillus pulmilus KCTC 3348 and Bacillus cereus IFO 12113) and mold (Aspergillus niger KCCM l1239) in bread was determined using the paper disk method. The green tea extract (GTE) showed the inhibition effects on the growth of all the strains of bacteria and mold at 1, 2, 3% levels. The activity of GTE was stable in the wide range of pH (4~9) and temperature (50~20$0^{\circ}C$). When green tea powder (GTP: 1, 3, 5%) was added to steamed bread increase of total bacterial and mold counts declined during storage at 25"C as the levels of GTP increased. By addition of 5% GTP, mold appeared 1 day late extending shelf life of steamed bread compared to control bread without GTP. Therefore, the levels of GTP added to steamed bread could be more than 5% for extended shelf life and wholesomeness of steamed bread.read.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.643-648
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• 2008

The principal objective of this study was to evaluate the effects of the addition of sourdough to bread dough, specifically with regard to the physicochemical characteristics of bread dough, organoleptic evaluation, and bread storage. Marked increases in lactic acid bacterial counts $10^{9-10}CFU/g$ in dough samples with 30, 50, and 100% of added sourdough to the respective bread dough were observed after the first fermentation period of the dough, but decreases were observed in yeast cells. The highest overall acceptance scores were recorded for the 100% sourdough-added bread, and almost no differences in taste and texture were detected between the regular bread (control bread) and sourdough-added bread on the sensory evaluations, with slightly lower evaluation scores (for sour taste) in the sourdough-added bread. The sourdoughadded bread also showed retarded mold growth in the bread on our storage tests. Six days had elapsed prior to the appearance of mold growth in the sourdough-added bread, whereas three days elapsed in the regular bread. The more sourdough was added to the dough, the less was the total count in bread. Increases of 13.1, 20.9, and 36.2% in the retardation of starch retrogradation of the bread were observed as the result of additional increases in sourdough quantity to bread at 30, 50, and 100%, respectively.

• Journal of the Korean Society of Food Culture
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• v.16 no.5
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• pp.470-477
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• 2001

This study was conducted to investigate the effect of garlic on the fermentation and organoleptic quality of kimchi. For this study, changes in pH, acidity, reducing sugar content and microbial count of kimchi during fermentation were tested and sensory test of fermented kimchi was also conducted. The acidity of kimchi with garlic was increased rapidly more than control kimchi at early stage of fermentation. Though the reducing sugar content was higher in kimchi with garlic than control kimchi, but that of all samples were almost same at mature stage of fermentation. Total bacteria and lactic acid bacterial counts were higher in kimchi with garlic than control kimchi at early stage of fermentation, but those were reversed at final stage of fermentation. By the result of sensory test, garlic was contributed to taste and aroma positively at level of $2{\sim}3g$ garlic to 100g of kimchi.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.1072-1077
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• 2007

Bacterial endospores, especially those of Bacillus and Clostridium genera, are the target of sterilization in various foods. We used Bacillus subtilis ATCC 6633 spores to screen novel antimicrobial substances against spores from medicinal plants. We collected 79 types of plant samples, comprising 42 types of herbs and spices and 37 types of medicinal plants used in traditional medicine in Korea and China. At a concentration of 1%(w/v), only 14 of the ethanol extracts exhibited antimicrobial activity against B. subtilis spores of at least 90%. Crude extracts of Torilis japonica, Gardenia jasminoides, Plantago asiatica, Fritllaria, and Arctium lappa showed particularly high sporicidal activities, reducing the spore count by about 99%. Consideration of several factors, including antimicrobial activity, extraction yields, and costs of raw materials, resulted in the selection of T. japonica, G. jasminoides, A. lappa, and Coriandrum sativum for the final screening of novel antimicrobial substances. Verification tests repeated 10 times over a 4-month period showed that the ethanol extract of T. japonica fruit reduced aerobic plate counts of B. subtilis spores the most, from $10^7$ to $10^4\;CFU/mL$ (99.9%) and with a standard deviation of 0.21%, indicating that this fruit is the most suitable for developing a novel antimicrobial substance for inactivating B. subtilis spores.

• Food Science of Animal Resources
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• v.37 no.1
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• pp.105-113
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• 2017

The effect of fermented spinach extracts on color development in cured meats was investigated in this study. The pH values of raw cured meats without addition of fermented spinach extract or nitrite (negative control) were higher (p<0.05) than those added with fermented spinach extract. The pH values of raw and cooked cured meats in treatment groups were decreased with increasing addition levels of fermented spinach extract. The lightness and yellowness values of raw cured meats formulated with fermented spinach extract were higher (p<0.05) than those of the control groups (both positive and negative controls). The redness values of cooked cured meats were increased with increasing fermented spinach extract levels, whereas the yellowness values of cooked cured meats were decreased with increasing levels of fermented spinach extract. The lowest volatile basic nitrogen (VBN) and thiobarbituric acid reactive substances (TBARS) values were observed in the positive control group with addition of nitrite. TBARS values of cured meats added with fermented spinach extract were decreased with increasing levels of fermented spinach extract and VBN values of curing meat with 30% fermented spinach extract was lower than the other treatments. Total viable bacterial counts in cured meats added with fermented spinach extract ranged from 0.34-1.01 Log CFU/g. E. coli and coliform bacteria were not observed in any of the cured meats treated with fermented spinach extracts or nitrite. Residual nitrite contents in treatment groups were increased with increasing levels of fermented spinach extract added. These results demonstrated that fermented spinach could be added to meat products to improve own curing characteristics.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.14 no.2
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• pp.57-63
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• 2008

The effects of airtight containers and zipper bags on the freshness extension of pine nuts (Pinus koraiensis) were studied at 4 and $25^{\circ}C$. Changes in total microbial growth, 2-thiobarbituric acid(TBA), color, and sensory quality were evaluated during storage. Total bacterial counts of the samples continuously increased over 28 days for airtight containers and 56 days for zipper bags, and then decreased at 70 days because the lack of air could affect the inhibition of the aerobic microbial growth. However no significant differences were observed between airtight containers and zipper bags. TBA values continuously increased with storage time, but there were no significant differences between the airtight containers and zipper bags during storage. Color changes and sensory evaluation analyses showed that the data revealed similar results for both packaging systems over the storage time. Therefore, it has been concluded that airtight containers and zipper bags could be used as a good packaging system to extend the shelf life of pine nuts by controlling the microbial growth, but the packaging systems of the airtight containers and the zipper bags was not significantly affect the quality parameters for 2-thiobarbituric acid(TBA), color, and sensory quality.