• Food Science and Preservation
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• v.17 no.5
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• pp.586-594
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• 2010

We evaluated changes in the microbiological quality and safety of food items (vegetables, seaweed, and processed food) supplied to elementary school food services to evaluate the distribution/delivery system. Pretreated vegetables, seaweed, and processed food were delivered to schools in refrigerated (${\leq}10^{\circ}C$) vans that made several delivery stops before arriving at the schools. During the distribution stage, total plate and coliforms counts were: bellflower roots $7.6{\times}10^5-6.7{\times}10^6$ and $5.8{\times}10^4-5.2{\times}10^5$ CFU/g; blanched bracken $4.5{\times}10^3-2.1{\times}10^5$, $5.0{\times}10^3-1{\times}10^4$ CFU/g; onion $1.2{\times}10^4-1.4{\times}10^4$, $5.0{\times}10$ CFU/g; soybean sprouts $9.6{\times}10^4-6.3{\times}10^7$ and $1.1{\times}10^3-1.2{\times}10^7$ CFU/g; soybean curd < $10-9.7{\times}10^5$ and < $10-2.3{\times}10^5$ CFU/g; and starch jelly < $10-3.8{\times}10^3$ and <10 CFU/g. Bacillus cereus < $10-4.1{\times}10^2$ CFU/g, Escherichia coli $1.0{\times}10-2.0{\times}10$ CFU/g, and Staphylococcus aureus $1.3{\times}10^2-4.1{\times}10^2$ CFU/g were detected on peeled bellflower, whereas B. cereus < $10-4.1{\times}10^2$ CFU/g, Listeria monocytogenes $1.0{\times}10-4.5{\times}10^2$ CFU/g, and S. aureus $1.8{\times}10^2-4.5{\times}10^2$ CFU/g, were detected on soybean sprouts. Most food items were double-wrapped in vinyl and placed in corrugated cardboard boxes prior to delivery, but the boxes, when placed in vans, were not segregated from other food items being delivered to schools and other destinations.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.2
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• pp.129-136
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• 2011

Microorganisms are the main causative factors of pulpal and periapical diseases, therefore successful endodontic treatment is depend on the effective elimination of intracanal bacterial populations. Many studies have been reported antimicrobial effect of Allyl isothiocyanate (AIT) which the principle ingredient of Horseradish (Armoracia rusticana) root extracts. The purposes of this study are to evaluate the antimicrobial effectiveness of Horseradish root extracts against Enterococcus faecalis in root canals of extracted human teeth and compare to sodium hypochlorite (NaOCl). Extracted human mandibular premolar root canals were infected with E. faecalis for 21 days, and then irrigated with Horseradish root extracts, NaOCl solution and saline. After canal irrigation, first samples (S1) were taken. After first sampling, the canals were additionally incubated 7 days, and then second samples (S2) were taken. The samples were inoculated on EHI agar plate to determine the colony forming units (CFU). 1. Mean values of CFU in S1 were $5.815{\times}10^3$ CFU/ml at Horseradish groups, and $3.465{\times}10^3$ CFU/ml at NaOCI groups. There was no statistically significant differences (p=0.086). 2. Mean values of CFU in S2 were $3.100{\times}10^3$ CFU/ml at Horseradish groups, and $5.252{\times}10^5$ CFU/ml at NaOCI groups. There was statistically significant difference (p<.05). 3. There was no statistically significant differences (p=0.076) between S1 and S2 at Horseradish groups in the mean values of CFU. However, there was statistically significant differences (p<.05) between S1 and S2 at NaOCI groups in the mean values of CFU.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.289-295
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• 2011

Produce, including leafy vegetables, has been implicated in several outbreaks of food illness. To evaluate microbiological safety of lettuce and it's cultivation area, a total of 147 samples were collected from lettuce farms and post harvest facility at Icheon, Gyeonggi province. The collected samples were assessed for presence of sanitary indicator microorganisms (Aerobic plate count, coliform count, Escherichia coli) and foodborne pathogens (Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus). The population of APC was over 4.0 log CFU from most of the samples. While the numbers of APC, and coliform of lettuce at 62 days after transplanting were 4.18 log CFU/g, and 1.00 log CFU/g, respectively, those of 10 days after transplanting were 5.37 log CFU/g, and 2.87 log CFU/g, respectively. B. cereus was highly detected from soil and balance which were contaminated with 3.5 log CFU/g, and 2.6 log CFU/100 $cm^2$, respectively. The number of E. coli recovered from gloves was 3.5 log CFU/hand. However, E. coli O157:H7, Salmonella spp., and L. monocytogenes were not detected. These data suggested that risk management system should be introduced to lettuce farms to enhance safety of lettuce.

• Food Science and Preservation
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• v.20 no.5
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• pp.650-658
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• 2013

Apple juices were sterilized by continuous pulsed electric field (PEF) treatments of pulse width of 25 ${\mu}s$ at electric field intensity of 20.0 kV/cm, and with the varied pulse frequencies of 35 Hz (40 kJ/L), 55 Hz (70 kJ/L), 72 Hz (100 kJ/L) and 85 Hz (130 kJ/L). The PEF treatments of apple juice reduced the microbial counts from 5.3 log CFU/mL of initial state to 3.0 log CFU/mL after PEF treatment at energy density of 130 kJ/L. Also yeast and fungi after PEF treatments were reduced from 5.3 log CFU/mL to 3.0 log CFU/mL and Escherichia coli were from 5.3 log CFU/mL of initial state to 4.7 log CFU/mL to < $10^1$ CFU/mL. The soluble solids and free sugars did not significantly differ (p<0.05) depending on conditions of PEF treatment. The total phenolic contents and antioxidant activity such as the DPPH and ferric reducing antioxidant power (FRAP) by PEF treatments were significantly partly reduced, but the PEF-reduced value came in smaller quantities than the heat treatment at $65^{\circ}C$. The iterative PEF treatments with pulse width of 25 ${\mu}s$ and pulse frequency of 85 Hz at electric field intensity of 20.0 kV/cm showed limited in microbial reduction. Also, total phenolic contents and antioxidant activity such as DPPH and FRAP, significantly decreased depending on treatment numbers of PEF (p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.224-230
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• 2006

Microbial contamination levels and legal preservative appropriation in child foods sampled from the neighborhood of elementary schools were investigated. Contamination levels of total aerobic bacteria in seasoned dried fish slices, bread and snacks, sausages, sugar products and dumplings were $1.70\~6.91,\;1.40\~6.66$, 4.50, $3.48\~5.88$, and $4.79\~4.82\;log_{10}$ CFU/g, respectively. Coliforms in four kinds of foods except for dumplings were $2.30\~6.60,\;4.22\~~5.98$, 2.00, and $2.78\;log_{10}$ CFU/g, respectively. Yeasts and molds in those foods were $0.10\~4.23,\;1.66\~4.91,\;1.46\~1.91,\;1.56\~4.26$, and $1.12\~1.84\;log_{10}$ CFU/g, respectively. S. aureus was isolated in $18\%$ of seasoned dried fish slices ($1.00\~2.84\;log_{10}$ CFU/g), $33\%$ of bread and snacks ($1.70\~1.79\;log_{10}$ CFU/g), $50\%$ of sausages ($3.28\;log_{10}$ CFU/g), $22\%$ of sugar products ($2.16\~2.88\;log_{10}$ CFU/g), and $100\%$ of dumplings $(1.18\~3.31\;log_{10}\;CFU/g)$ B. cereus was isolated in $21\%$ of seasoned dried fish slices $(0.70\~2.48\;log_{10}\;CFU/g)$, $50\%$ of bread and snacks $(0.70\;log_{10}\;CFU/g)$, and $11\%$ of sugar products $(0.30\;log_{10}\;CFU/g)$. Both E. coli and Salmonella spp. were not isolated in all samples. Preservative was only labeled on four products among 15 products but preservative on 13 products including 4 products haying an indication of preservative were not detected. Moreover, $0.30\%$ of sorbic acid was detected in one of Squid products . The results of this study indicated that the hygienic level of child foods in Gyeonggi and Incheon was very poor and need to be improved.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.252-260
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• 2009

Whereas the numbers of childcare centers and kindergartens are increasing rapidly, systematic management to control the food safety of foodservice operation is not yet well established. Samples from 12 centers in Seoul and Gyeonggi Province were collected to assess the microbiological quality of 32 raw materials, 24 cooked foods, 76 food-contact surfaces (knives, cutting boards, dish towels and gloves), 17 employees' hands and 12 air-borne bacteria. The microbiological analyses were performed for aerobic plate counts (APC), Enterobacteriaceae, E. coli and 7 pathogens (B. cereus, C. jejuni, C. perfringens, L. monocytogenes, Salmonella spp., S. aureus, and V. parahaemolyticus). Among raw materials, E. coli ($1.39{\sim}2.08\;\log\;CFU/g$) were detected in 4 out of 6 meats and 7.46 log CFU/g of APC in tofu. High enterobacteriaceae levels of 4.23, 5.14 and 4.19 log CFU/g were found in cucumber salad, steamed spinach with seasonings and steamed bean sprout with seasonings, respectively. No pathogens were found in all samples except for C. perfringens detected from raw spinach and raw lotus root. Only APC and enterobacteriaceae were found in food-contact surfaces. Two of the 23 knives and three of the 24 kitchen boards showed over 500 CFU/$100\;cm^2$ of APC; also, APC levels (5.03 to 5.44 log CFU/g) were detected in 4 of the 12 dish towels. Only one glove showed Enterobacteriaceae (2.44 log CFU/glove) contamination. Enterobacteriaceae were found in 2 employees' hands ($2.37{\sim}4.44\;\log\;CFU$/hand) among the 16 employees. The contamination levels of air-borne bacteria were shown unacceptable in two (2.25 and 2.30 log CFU/petri-film/15 min) out of the 12 kitchen areas. These results suggest that the microbiological hazards in some foods and environments are not well controlled and thus a guideline should be provided to ensure the food safety in childcare center and kindergarten foodservice operations.

• Korean Journal of Organic Agriculture
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• v.19 no.3
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• pp.417-425
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• 2011

This study was conducted to investigate the changes in physicochemical and microbiological properties during fermenting process of farm-made organic liquid fertilizer made of the mixture of organic materials such as blood meal and molasse during fermenting process. The pH level of organic liquid fertilizer during the ermentation decreased from 7.2 to 4.3. The EC of organic liquid fertilizer was increased from 13.9 dS/m to 99.3 dS/m during the fermentation. The total population of aerobic bacteria decreased from $8.2{\times}10^5$ cfu/ml to $3{\times}10^4$ cfu/ml, but Bacillus spp. increased from $2.1{\times}10^2$ cfu/ml to $4.2{\times}10^3$ cfu/ml during the fermentation. Bacterial isolates were obtained from organic liquid fertilizers and identified by fatty acid-base typing. The Genus Bacillus was dominant as fermenting proceeded. The denaturing gradient gel electrophoresis (DGGE) profile showed changes of bacterial communities in organic liquid fertilizers.

• Journal of fish pathology
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• v.20 no.3
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• pp.229-235
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• 2007

Cell number of Vibrio spp. was examined for the surface and bottom sea water harvested from the 9 stations in the Jeonam Archipelago Marine Ranching Ground in 2006～2007. Species population composition and dominant species were analyzed as well. The largest number of Vibrio spp. was detected in summer (June, 2007) among the 4 seasons with the surface and bottom sea water samples of 5.4～93.2 cfu㎖-1 and 1.0～53.1 cfu㎖-1. respectively. In winter (January, 2007), Vibrio spp. was not detected at all except that one station from which 0.2 cfu㎖-1 of Vibrio spp. was counted in the surface sea water sample. Cell numbers were 0～11.9 cfu㎖-1 and 0～8.3 cfu㎖-1, respectively, in the surface and bottom sea water samples retrieved in spring (April, 2007), and the corresponding sea water samples in autumn(November, 2006) were contaminated with 0.1～21.4 cfu㎖-1 and 0～2.9 cfu㎖-1, respectively. Species population composition of Vibrio spp. was found to be V. parahaemolyticus, V. alginolyticus and V. cholerae non-01 among which V. parahaemolyticus and V. alginolyticus were dominant in all seasons. V. alginolyticus was detected from all stations even in the winter season indicating that this species seems to be less temperature dependent than the other Vibrio spp..

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.177-182
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• 2020

This study evaluated the effect of steam heating, gamma irradiation, and ultraviolet (UV) irradiation on microorganism reduction in order to determine an effective sterilization method for red pepper powder. The effect of each treatment on the reduction of thermoduric bacteria and total aerobic bacteria in red pepper powder were as follows: 10 kGy gamma irradiation, reduction of 4 log and 6 log CFU/g, respectively; 12 mW/㎠ UV irradiation (264 nm UV-C), reduction of less than 1 log CFU/g; steam heating at 120℃ for 40 s, reduction of approximately 2 log CFU/g. High-temperature short-time processing at 110℃ for 30 s reduced the total bacterial count in Gochujang solution from 5.70 log CFU/g to 2.26 log CFU/g; at 121℃, the solution was commercially sterile. Steam heating resulted in 1, 2, and 4 log microbial inactivation in garlic, onion, and pepper powder, respectively. Steam sterilization, which consumers prefer over other methods, may be an effective method for reducing microorganisms in spice powders, including those in red pepper powder.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.594-598
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• 2006

The aim of this study was to investigate the prevalence and frequency of food-borne pathogens in unprocessed Products such as grains, tubers, vegetables, and seaweeds. Three hundred and twenty seven samples were purchased from the retail market and the supermarket in the Kyonggi-do and Seoul areas, and washed with running tap water for 4 minutes. The total aerobic bacteria count was approximately 2 to 6 log CFU/g and the highest counts were 6 log CFU/g far lettuce and sesame leaf. The coliform count showed 1-5 log CFU/g and the highest counts were 4 log CFU/g for lettuce and carrot. Escherichia coli was detected in seven samples of white rice, sweet potato, lettuce, sesame leaf, and cabbage. Clostridium perfringens was detected in six samples of brown seaweed, laver, lettuce, and sweet potato. However, Bacillus cereus contamination was found in more than 30% of brown rice, carrot, sweet potato, lettuce and sesame leaf samples, and some of these showed contamination of more than 2.0 log CFU/g. Therefore, these results suggest that pretreatment with sanitizer to remove Bacillus cereus in such products is necessary.