• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제10권1호
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• pp.115-125
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• 2000

Three major hospitals with over 500 beds located in and near Seoul were surveyed for airbone microorganisms from February 1, 1998 to February 18, 1998. The purpose of the study was to identify and quantify microbiological organisms circulating in the air of three different areas in the hospitals. For the study, a RCS air sampler was utilized equipped with two different collection media, the agar strip GK-A for bacteria and the agar strip HS for fungi. The areas investigated were the intensive care unit (ICU) in the Department of internal medicine, the Newborns room in the Department of Obstetrics, and the microbiology laboratory. The results were as follows; 1. The average numbers of general microbiological particles collected on the agar strip GK-A media were $205CFU/m^3$, $232CFU/m^3$, and $128CFU/m^3$ in each hospitals. The highest concentration of $387CFU/m^3$ was found in the ICU of A hospital at 15:00 during the day. Further analysis of the collected bioaerosols by gram staining, revealed that there were gram positive cocci (89.5%), gram positive bacilli (7.2%), gram negative bacilli (2.8%), and fungi (0.5%), in descending order of frequency. 2. Ten different genes were identified from the agar strip GK-A. The most frequently identified organisms were: the Coagulase negative staphylococcus (55.0%), Micrococcus (21.4%), Enterococcus species(10.4%), and Bacillus species (7.2%). A series of antibiotics susceptibility test were conducted against the aforementioned four(4) organisms. Ninety percent of coagulase negative stapylococcus were sensitive to Penicillins. Pathogenic microbes isolated include: Staphylococcus aureus, Acinetobacter species, Klebsiella pneumonia, Klebsiella oxytoca, and Pseudomonas aeroginosa. 3 Although 56.8% of the microorganisms grown on the strip HS media for fungi could not be identified, some of them were successfully identified. The most frequently found fungi were Aspergillus (35.3%), Yeast or Molds (6.2%), and Penicillium (0.7%). Based on the results obtained from the study, it was concluded that some areas in the hospitals had abnormally high bioaerosol concentrations which could be attributed to human activity. Therefore, it is recommended that periodic assessments of indoor bioaerosols aiming to identify the possible sources should be conducted in order to maintain clean indoor environment in the hospitals.

• Food Science and Preservation
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• 제11권4호
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• pp.530-537
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• 2004

This study was conducted to determine the inactivation effect of electrolyzed water and organic acids either alone or in combination on L. monocytogenes or natural microflora on lettuce. Acidic electrolyzed water completely inactivated L. monocytogenes in broth system within 60 sec, but alkalin electrolyzed water caused approximate 1.7 log CFU/g reduction. However, acidic electrolyzed water reduced only 2.5 log CFU/g of L. monocytogenes on lettuce, and similar antimicrobial effect was observed with alkalin electrolyzed water. In the meantime, acidic and alkaline electrolyzed water caused approximately 2 log CFU/g reduction compared to control, whereas both electrolyzed water combined with $1\%$ organic acids ranged from 2.6 to 3.7 log CFU/g reduction. Among the organic acids, both electrolyzed water combined with $1\%$ citric acid showed the strongest synergistic antimicrobial effect to reduce L. monocytogenes on lettuce as well as total counts, yeast and molds. When antimicrobials, alone or in combination were treated into L. monocytogenes inoculated lettuce at $5^{\circ}C\;and\;15^{\circ}C$ for designed periods, the combined alkalin electrolyzed water with $1\%$ citric acid showed the greatest potential to inhibit growth of the bacteria. According to Scanning Electron Microscopy(SEM), the treatment of electrolyzed alkali water in combination with $1\%$ citric acid highly reduced the growth of the L. monocytogenes compared to single treatment and resulted in causing the destruction of cell membrane.

• Food Science and Preservation
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• 제22권5호
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• pp.758-767
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• 2015

Red pepper powder sensitive to aflatoxins contamination is major ingredients of kimchi. This study was conducted to investigate the effect of lactic acid bacteria (LAB) on the changes in aflatoxin levels during kimchi fermentation. Baechu kimchi was contaminated with aflatoxins ($B_1$, $B_2$, $G_1$, and $G_2$) and inoculated with LAB (Lactobacillus plantarum and Leuconostoc mesenteroides), and the following characteristics were investigated for 8 weeks: pH, titratable acidity, salinity, microbial properties, and aflatoxin levels. The pH decreased rapidly during storage, and the titratable acidity was increased. The salinity of the samples was shown to increase from 2.30 to 2.40%. The total number of aerobic bacteria and lactic acid bacteria in kimchi inoculated with LAB was significantly higher than that of the others. Yeast and molds were detected at approximately 1~3 log CFU/g during storage. Coliforms were detected in the control after 4 weeks, whereas in other samples they were not detected until after 2 weeks. The aflatoxin levels reduced during kimchi fermentation. The average reduction rate of aflatoxin levels during kimchi fermentation was 8.39%, but in kimchi inoculated with Lac. plantarum and Leu. mesenteroides, the rate were 25.16 % and 27.86%, respectively. These results showed that aflatoxins can be removed by LAB during kimchi fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• 제36권1호
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• pp.111-116
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• 2007

We examined the antimicrobial activity of electrolyzed alkaline water against spoilage microorganisms in rice warehouses. Dominant microbial species were isolated from paddy, dust and air samples of three different warehouses located in Gyeongnam. We used electrolyzed alkaline water (EW) manufactured over various treatment times. The acidities (pH) of EW treated for 30 sec, 1, 2, 3, and 4 min were 8.89, 8.91, 9.20, 9.35, and 9.22, respectively. HClO contents were 150.7, 314.2, 191.8, 104.1, and 255.3 ppm, respectively. EW inhibited bacteria, yeasts, and molds; also, it inhibited three yeast species strongly. The antimicrobial effects of EW increased as pH values and HClO contents increased. EW obtained after 30 sec treatment retained the antimicrobial activities after 14 days whereas EW obtained after 1 and 2 min treatments retained the antimicrobial activities after 21 and 24 days, respectively.

• Journal of Food Hygiene and Safety
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• 제27권4호
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• pp.442-448
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• 2012

This study investigated reduction of microbial population, water soluble pigment, capsanthin content, surface color (Hunter L, a, b, ${\Delta}E$), and sensory properties of pepper powder by LED (red, yellow, blue, green) treatments. LED (red, yellow, blue, green) treatment were conducted in 1,000 lux storage at $25^{\circ}C$ for 10 days. The total aerobic bacteria was no significant difference among the control and treated with LED during 10 days. In yellow LED treatment, yeast and molds were decreased about 1.76 log. Surface color such as lightness (L), redness (a), yellowness (b) were showed a decreasing tendency as the storage period. In the overall color difference (${\Delta}E$) of yellow LED treatment was lower less than 3.0. Water soluble pigment was no difference in control and LED treated samples during storage period. Capsanthin content was significantly decreased as storage period was increased, but no significant differences were observed among red and yellow LED treatments. Sensory properties of control was significantly reduced by storage period but yellow and green LED treatments were no significantly differences.

• Applied Biological Chemistry
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• 제50권1호
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• pp.42-47
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• 2007

Effect of chlorine dioxide ($ClO_2$) treatment on the microbial and physicochemical changes of fish paste was investigated. Fish paste samples were treated with 5, 10, and 50 ppm of $ClO_2$ solution, respectively, After $ClO_2$ treatment, fish paste samples were individually packaged and stored at 4$^{\circ}C$. The initial microbial loads of samples were 3.8 log CFU/g in total bacterial count, and 2.5 log CFU/g in yeasts and molds. Microbial growth of fish paste during storage showed that populations of total bacteria, yeast and mold were significantly reduced by $ClO_2$ treatment. In particular, the treatment of 50 ppm $ClO_2$ decreased total bacterial count the most significantly among the $ClO_2$ treated fish pastes. The pH and VBN of fish paste decreased with increasing $ClO_2$ concentration. Thiobarbituric acid reacted substance (TBARS) values of treated fish paste increased during storage, regardless of $ClO_2$ concentration. This study showed that 50 ppm chloride dioxide was the optimum dose level to extend the shelf-life of fish paste.

• Applied Biological Chemistry
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• 제8권
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• pp.45-50
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• 1967

Starch was liquefied by the bacteriological ${\alpha}-amylase$ and saccharified separately by four strains of mold as saccharogenic enzymes, then thise was fermented for research the fermentation rates, the usefulness of application of four strains of mold and the S.P to need in proportion increasing of concentration of mixed-starches for brewing in this experiment. The obtained results were as follows: 1) In the ability of saccharificatien, fermentation and acid resistance, Aspergillus usamii mut shirousamii, which were used to produce the koji, were excellent, however, Rhizopus delemar had heavy pollution in a lot of production of koji, were-as its qualities as enzyme was good. 2) The necessary S.P in proportion to the concentration of mixed-starch for brewing was found in this experiment in which was fermented in the various concentration of the adding S.P and the mixed-starches for brewing. 3) In the experiment of almost manufacture scale, the S.P needed essentially in the saccharogenic formentation was found and the usefulness of the necessary S.P was observed, and in fact in the manufacture scale it was safer to add the S.P more than 1.2% because it must be considered that the ability of enzymes is reduced by heat or acid. 4) The period of fermentation was shorten because the conditions for yeast propagation were excellent as a results of starches being liquefied by bacteriological amylase, and saccharified by molds as saccharogenic enzymes.

• Food Science of Animal Resources
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• 제28권1호
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• pp.76-81
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• 2008

The objective of this study is to evaluate the microbial safety of raw pork used to produce Korean pork jerky. The raw pork samples harbored large populations of microorganisms. In particular, mesophilic bacteria were found to be most numerous $(3.9{\times}10^2-3.9{\times}10^5cfu/g)$ in the samples. Spore-forming bacteria and coliforms were not detected below detection limit. Yeast and molds were detected at $3.8{\times}10^1-5.1{\times}10^2cfu/g$ in the raw pork. Ten samples of raw pork were analyzed for the presence of pathogenic bacteria. Bacillus cereus was isolated from samples B and J and Staphylococcus aureus was isolated from sample B. The B. cereus isolates from raw pork samples were identified with 99.8% agreement and S. aureus isolate was identified with 97.8% agreement according to the API CHB 50 kit.

• Journal of Ginseng Research
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• 제33권4호
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• pp.361-366
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• 2009

This research aims to develop a new drying technology using super-heated steam to reduce the time required for drying ginseng and to enhance its quality. The drying rate of ginseng powder treated with hot-air drying after drying with super-heated steam was about 40% faster than the drying rate of ginseng powder treated with hot-air drying. Minimal difference was found between hot-air drying and hot-air drying after drying with super-heated steam in the general composition of the ginseng powder, such as its crude lipid, crude protein, crude fiber, and ash. Moreover, no difference was found between hot-air drying and hot-air drying after drying with super-heated steam in terms of the ginseng powder's mineral and free sugar contents. The crude saponin contents was 5.43% in the ginseng treated with hot-air drying and 5.4% in the ginseng treated with hot-air drying after drying with super-heated steam. The ginseng powder that was treated with hot-air drying after drying with super-heated steam had a slightly higher redness compared to the ginseng powder that was treated with hot-air drying alone. The number of microorganisms of the ginseng powder treated with hotair drying after drying with super-heated steam showed a reduction of one log cycle in the total bacteria and two log cycles in the yeast molds compared to the ginseng powder treated with hot-air drying alone.

• Food Science and Preservation
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• 제17권2호
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• pp.196-201
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• 2010

Gelatin films containing grapefruit seed extract (GSE) were prepared by incorporating different amounts (0, 0.6, and 1.0%, w/v) of GSE into film-forming solutions. Film elongation was improved by the addition of GSE, but film tensile strength decreased to 31.96 MPa for film containing 1.0% GSE, compared with 46.39 MPa for the control. Incorporation of 1.0% GSE inhibited the growth of pathogenic bacteria such as Escherichia coli O157:H7 and Listeria monocytogenes. Packaging of strawberries with a gelatin film containing 1.0% GSE decreased the levels of total aerobic bacteria and yeast/molds after 12 days of storage by 1.60 and 1.43 log CFU/g, respectively, compared with control values. Sensory evaluation results indicated that packaging of strawberries with GSE-gelatin film resulted in better sensory scores than those of the control. These results indicate that strawberries can be packaged using gelatin film containing GSE, to extend shelf-life.