• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.123-127
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• 2011

This study was conducted to decrease the microbial hazard in kimchi saline water with microwave plasma sterilization system and to evaluate the inactivation of foodborne pathogens by the microwave plasma sterilization system as a non-thermal treatment. Contamination of coliform, Escherichia coli, and yeasts and molds were detected in the used saline water, and the microbial populations increased as the saline water was reused repeatedly. The $D_{10}$-values of E. coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes by the microwave plasma sterilization system were 0.48, 0.52, and 0.45 cycle, respectively. In addition, the microbial populations of coliform, E. coli, Salmonella spp., total aerobic bacteria, and yeasts and molds in the used kimchi saline water were significantly decreased by treating the saline water using the microwave plasma sterilization system. Therefore, these results suggest that microwave plasma sterilization system can be useful in improving the microbial safety of the used saline water.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.94-101
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• 2018

Although Kimchi has health benefits, food poisoning associated with consumption of Kimchi has been frequently reported. Accordingly, microbiological properties of Kimchi (100 samples) and washing effects on microbial reduction against its ingredients (200 samples) were examined. Total aerobic bacteria, coliforms, Escherichia coli, Bacillus cereus, and Clostridium perfringens were quantified. In addition, B. cereus, Salmonella spp., Enterohemorrhagic E. coli, C. perfringens, Campylobacter jejuni/coli, Staphylococcus aureus, Vibrio parahaemolyticus, Listeria monocytogenes, and Yersinia enterocolitica were analysed qualitatively. Total aerobic bacteria count was approximately 1.4-9.0 log CFU/g, which were highest in ginger (8.8 log CFU/g), and Chonggak Kimchi (9.0 log CFU/g). The range of coliform counts detected in all raw materials was 0.5-7.3 log CFU/g and ginger showed the greatest number 7.3 log CFU/g among others. Contamination was decreased to 0.2-3.2, 0.3-2.7, and 1.0-3.9 log CFU/g for total aerobic bacteria, coliforms, and B. cereus, respectively, after washing. Minimising microbial contamination in Kimchi ingredients is necessary to ensure the safety of Kimchi. These results indicate that washing is a useful method to reduce bacterial contamination in Kimchi.

• Food Science and Preservation
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• v.15 no.5
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• pp.769-773
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• 2008

Aqueous chlorine dioxide ($ClO_2$) treatment of Samgae chicken was evaluated in terms of microbial safety and quality during refrigerated storage. Samgae chicken samples were treated with 0, 50, or 100 ppm of $ClO_2$ solution, and stored at $4^{\circ}C$ for 10 days. $ClO_2$ treatment significantly decreased the populations of total aerobic bacteria. One-hundred ppm $ClO_2$ treatment reduced the initial populations of total aerobic bacteria by 0.73 log CFU/g. The pH and volatile basic nitrogen values of Samgae chicken increased during storage, with no significant between-treatment difference. Sensory evaluation results showed that the quality of chicken treated with $ClO_2$ prior to refrigerated storage was better than that of the control. These results suggest that $ClO_2$ treatment could be useful in improving the microbial safety and quality of Samgae chicken.

• Food Science of Animal Resources
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• v.29 no.3
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• pp.289-295
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• 2009

The aim of this research was to develop predictive models for the growth of spoilage bacteria (total viable cells, Pseudomonas spp., and lactic acid bacteria) on frankfurters and to estimate the shelf-life of frankfurters under aerobic conditions at various storage temperatures (5, 15, and $25^{\circ}C$). The primary models were determined using the Baranyi model equation. The secondary models for maximum specific growth rate and lag time as functions of temperature were developed by the polynomial model equation. During 21 d of storage under various temperature conditions, lactic acid bacteria showed the longest lag time and the slowest growth rate among spoilage bacteria. The growth patterns of total viable cells and Pseudomonas spp. were similar each other. These data suggest that Pseudomonas spp. might be the dominant spoilage bacteria on frankfurters. As storage temperature increased, the growth rate of spoilage bacteria also increased and the lag time decreased. Furthermore, the shelf-life of frankfurters decreased from 7.0 to 4.3 and 1.9 (d) under increased temperature conditions. These results indicate that the most significant factor for spoilage bacteria growth is storage temperature. The values of $B_f$, $A_f$, RMSE, and $R^2$ indicate that these models were reliable for identifying the point of microbiological hazard for spoilage bacteria in frankfurters.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.888-893
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• 2001

Soy sauce has a long history used as a food ingredient. However, hydrolyzed vegetable protein, mono-sodium glutamate, starch syrup, and fructose are added to soy sauce during fermentation for the taste and flavor of product. But consumers have been reluctant to the taste of these artificial additives. In this experiment, anchovy sauce was used to prepare soy sauce to enhance the quality and brine was used as a control. To evaluate the quality of soy sauce added with anchovy, total nitrogen (TN) and soluble nitrogen contents, total soild contents, total sugar reducing sugar. lactic acid content and protease activity were monitored during fer-mentation. Total microbial numbers and lactic acid bacteria were not significantly changed among the cases. Aerobic and anaerobic microorganisms. and lactic acid bacteria were not significantly changed among the cases we studied, For the total sensory test, it was also estimated that the cases using anchovy sauce were superior to the control. From the results mentioned above, we could obtain shorter fermenation period as well as the quality improvement in the case of using anchovy sauce instead of salty water in the fermented soy sauce production.

• Journal of Environmental Health Sciences
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• v.38 no.6
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• pp.510-519
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• 2012

Objectives: This study was conducted in order to evaluate the microbiological contamination of the indoor air of the lunchrooms at child care centers and investigate the toxin genes and toxin production ability of food-borne pathogens. Methods: A total of 64 child care centers were sampled to test total aerobic bacteria, coliform bacteria, fungi, Staphylococcus aureus, Bacillus cereus and Salmonella spp. according to the Korea Food Code. All toxin genes of pathogens were detected using the Polymerase Chain Reaction method. The Sthaph. aureus enterotoxin was detected by a Staphylococcus aureus enterotoxin-reversed passive latex agglutination kit. The heamolysin BL (HBL) and non-heamolytic enterotoxin (NHE) produced by B. cereus were detected using a B. cereus enterotoxin-reversed passive latex agglutination kit and Bacillus diarrheal enterotoxin visual immunoassay kit, respectively. Results: The means of total aerobic bacteria and coliform bacteria were $1.91{\pm}1.84$ log CFU/plate and $0.47{\pm}0.62$ log CFU/plate, respectively. The mean of fungi also showed $0.59{\pm}0.71$ log CFU/plate. Among the pathogenic bacteria tested in this study, Staphy. aureus and B. cereus were detected in four (6.3%) and 21 (32.8%) out of 64 indoor air samples from lunchrooms in child care centers, respectively. All Staphy. aureus tested in this study possessed no toxin genes and did not produce enterotoxin. The detection rate of nheABC, hblCDA, entFM and ces toxin gene in B. cereus was 100, 57.1, 76.2 and 0%, respectively. B. cereus isolates were classified into four groups according to the presence or absence of toxin genes. The nheABC gene was the major toxin gene among B. cereus tested in this study. The HBL was detected in 11 out of 21 B. cereus isolates (52.4%) and three B. cereus isolates produced NHE (14.3%). Conclusion: The results indicated that the contamination by microorganisms in the indoor air of lunchrooms was unqualified to supply safe catering in child care centers. The ongoing control of indoor air quality is required.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.316-319
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• 2011

Biopiles which offer the potential for cost-effective treatment of contaminated soils are above-ground, engineered systems that use oxygen to stimulate the growth and reproduction of aerobic bacteria for degradation of the petroleum constituents adsorbed to soil in excavated soils. This technology involves heaping contaminated soils into piles and stimulating aerobic microbial activity within the soils through the aeration and/or addition of minerals, nutrients, and moisture. Inside the biopile, microbially mediated reactions by blowing or extracting air through the pipes can enhance degradation of the organic contaminants. The influence of a aeration system on the biopile performance was investigated. Air pressure made to compare the efficiency of suction in the pipes showed that there were slightly significant difference between the two piles in the total amount of TPH biodegradation. The normalised degradation rate was, however, considerably higher in the aeration system than in the normal system without aeration, suggesting that the vertical venting method may have improved the efficiency of the biological reactions in the pile.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.532-535
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• 2003

Indigenous bacterial mediation of As in contaminated sediment after biostimulation with a variety of carbon sources was investigated under aerobic and anaerobic conditions. Under the aerobic condition with lactate supply, indigenous bacteria increased the amount of total As extracted from the sediment and most dissolved As existed as As(V). Under the anaerobic, glucose-supplied condition, dissolved As diminished with time likely due to production of As sulfide(s) and subsequent precipitation, which resulted from bacterial reduction of ${SO_4}^{2-}$. The results implied that bacterial natural attenuation of As in subsurface has a potential to be practically applied.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.355-360
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• 2004

Residual contamination levels of natural microflora in strawberries were evaluated. Approximate counts of total aerobic mesophilic bacteria, total coliforms, and lactic acid bacteria were 8, 2, and 3 log CFU/g, respectively, whereas those of Escherichia coli and yeasts/molds were under the detection limit (<10 cells/g). Growth inhibition degrees of total aerobic mesophilic bacteria, total coliforms, and lactic acid bacteria were also evaluated based on three hurdles of preservative, storage temperature, and pH of strawberry paste prepared as model system. Strawberry paste was stored at low ($4^{\circ}C$), room ($20^{\circ}C$), and high ($37^{\circ}C$) temperatures. Potassium sorbate was added as a preservative up to 0.1%. Acidity of strawberry paste was adjusted to pH 4 or 7. During 7-day storage, inhibitory effects of the hurdles against bacterial groups were: storage temperature > pH of strawberry paste > addition of potassium sorbate. Combination of three hurdles most effectively inhibited growth of residual microflora.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.202-206
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• 2014

In this study, the bacteriological survey was examined on ice creams at manufacturing factories in Korea during the summer season of 2011. The nineteen selected among 166 samples by preliminary test were collected from 11 different manufacturing factories in four major manufacturers in May 2011. Samples from ice milk, ice creams, sherbets, and non milk fat ice creams were tested for the total aerobic bacteria, coliform bacteria, and five food borne pathogens, respectively. The results showed that the coliforms including E. coli O157:H7, Salmonella spp., Staphylococcus aureus, Clostridium perfringens, and Listeria monocytogenes were not detected on all the ice creams. The total aerobic bacteria of the packed samples examined ranged between $2.5{\times}10^3$ and $5.5{\times}10^5cfu/g$. One ice cream, two sherbets, and four ice milk samples exceeded the acceptable limits of total aerobic bacteria according to the Korean standards for ice cream ($1.0{\times}10^5cfu/g$) and others ($5.0{\times}10^4cfu/g$). The levels of these microorganisms from ice creams were higher in three original equipment manufacturers than seven self-manufacturers. Three of ten ice creams (30.0%), three of six ice milks (50.0%), and one of two sherbets (50%) exceeded the acceptable limits of total aerobic bacteria, respectively. The personnel hygiene procedures with chocolate and vanilla chip addition from the manufacturing process were the main sources of the microbial contamination of stick-bar type ice creams when being produced in a factory. Improvement of the hazard analysis critical control points (HACCP) system should be introduced into the ice cream factory to improve the microbial quality of the ice cream products in Korea.