• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.75-82
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• 2001

Microorganisms can attach firmly to food contact surface material and the resitance of adherent bacteria differ markedly from planktonic cells. Therefore, adherent cells are a potential contamination problem to the food preparation because of their high resistance. to sanitation and heat treatment. This study was carried out in order to investigate growth and decontamination of Listeria monocytogenes attached to stainless steel, glass and plastic. Listeria monocytogenes cells could attach to all types of surface at three temperatures after contact times for 24 hrs. The numbers of adherent cells were greater at higher temperatures, but not increased with incubation time. When recovery of adherent cells was investigated, after 24 grs, the numbers of adherent cells were about 10$^{7}$ , 10$^{10}$ , 11$^{11}$ at 4$^{\circ}C$, $25^{\circ}C$, 3$0^{\circ}C$ repectively. Planctonic cells decreased by 2 log cycles after exposure to the domestic sanitizer. Adherent cells showed high resistance to domestic sanitizers and that was dependent upon surface materials studied, being greatest on plastic followed by stainless steel and glass. Adherent cells were more resistant to heat treatment than planktonic cells. When adherent cells were exposed to the temperature of 5$0^{\circ}C$, 55$^{\circ}C$, 57.5$^{\circ}C$ for 10 min, their populations did not decrease significantly. When the temprature increased to 6$0^{\circ}C$, cells attached to all types of surfaces were completely inactivated for 10 min.

• Food Science and Preservation
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• v.16 no.6
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• pp.971-976
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• 2009

The consumption of raw sprouts has increased in popularity worldwide because the food is natural and healthy. However, in Korea, nothing is known on the safety standards of sprout producers or changes in the microbial populations of sprouts during sprouting. We evaluated the microbial safety and quality of sprouts during each step in the sprouting process. Bacteriological analysis showed that seeds had a Total Plate Count (TPC) ranging from 3.04 - 5.21 log CFU/g and coliform counts ranging from 1.80 - 3.86 log CFU/g. TPC and coliform counts increased rapidly during the sprouting process to attain values of 6.99 - 8.26 and 3.70 - 7.15 log CFU/g, respectively, regardless of decontamination of seeds with commercial sanitizer. TPC and coliform counts were on high level after sprouts were washed. Escherichia coli was detected in samples of domestic radish sprouts at all stages from seed to storage, rape sprouts in the stages from soaked seed to storage, and red radish sprouts during sprouting, and no sanitizer was used in any of these processes. Untreated red radish sprouts were also positive for Bacillus cereus at all processing steps and Listeria monocytogenes after germination. However, pathogens were not detected at any sprouting stage of seeds treated with sanitizer. It is necessary to carefully control commercial sprouting, and to develop HACCP guidelines applicable to all sprouting processes, commencing at the first step in raw seed production.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.235-242
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• 2007

This study was conducted to investigate the effect of aerosolized chemical sanitizers on inhibiting foodborne pathogens such as Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes. Five domestic commercial sanitizers subjected to five groups of sanitizer (chlorine-based, hydrogen peroxide-based, Iodophor-based, quaternary ammonium-based, and alcohol-based sanitizers) were aerosolized by an aerosol generator into a model cabinet and treated in laboratory media containing three pathogens for 1 h at room temperature. Aerosolized hydrogen peroxide-based and quaternary ammonium-based sanitizers were effective at inhibiting levels of E. coli O157:H7 (ca. 4-9 log reductions) whereas other aerosolized sanitizers such as chlorine-based, Iodophor-based, and alcohol-based sanitizers did not significantly reduced the levels of E. coli O157:H7. For S. typhimurium, the only aerosolized hydrogen peroxide-based sanitizer was effective and resulted in ca. 5-9 log reduction. Aerosolized hydrogen peroxide-based, Iodophor-based, and quaternary ammonium-based sanitizers significantly reduced levels of L. monocytogenes and especially, aerosolized quaternary ammonium-based sanitizer was strongly effective to kill L. monocytogenes, resulted in higher than 8.8 log reduction. And there was no special trend in inhibitory efficacy of sanitizers aerosolized by 1.6 or 2.4 MHz aerosol generators. From these results, aerosolization has great potential for use in commercial applications however it's efficacy could be very different depending on type of sanitizers.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.1042-1047
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• 2005

Effects of sanitizers and disinfectants on microorganisms in food-processing plants were investigated. Chlorine and hydrogen peroxide were most effective, showing approximately 2-3 log reductions, among products tested, whereas alcohol showed less than 1 log reduction. Before using sanitizer and disinfectant in food processing plants, aerobic plate, coliforms, and E. coli counts were about $10^1-10^5,\;10^1-10^2$, and below $10\;CFU/cm^2$, respectively. After use of sanitizer, APC decreased to $10^1-10^2$. The result to confirm sanitizing effectiveness for 2 months using showed that Alcohol compound, QAC, hydrogen peroxide compound were effective against Staphylococcus aureus ATCC 6538 and E. coli ATCC 10536 at recommended usage concentrations, whereas effectiveness of chlorine compound decreased from 8 to 4 log 2 weeks after opening of product. Although sanitizers and disinfectants approved by law showed 5 log reduction in vitro for S. aureus ATCC 6538 and E, coli ATCC 10536, sanitizing effectiveness in food processing plants was very low, and effectiveness decreased once used product was stored.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.671-677
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• 2005

Conformity to legal permission standard of $5\;log_{10}$ CFU/mL reduction of foodborne pathogens or spoilage bacteria such as Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aruginosa, and Enterococcus hirae was examined in 11 domestic commercial sanitizers and disinfectant. One chlorine compound, two iodophor compounds, two peroxide compounds, and three quaternary ammonium compounds (QACs) met advised standard concentration (100%), showing $7\;log_{10}$ CFU/mL reduction, and met legal standard by $5-6\;log_{10}$ CFU/mL reduction at 75% of advised standard concentration. At 10% dilution, one chlorine compound, one iodophor compound, two peroxide compounds, and two QACs satisfied legal standard.