• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.39-44
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• 2011

This study was carried out to examine microbiological contamination of ready-to-eat products and to propose a draft-standard and specifications according to food types. RTE foods were classified into 6 groups including fish products, meat products, breads, rices, salads, and fresh cut foods. The prevalence rates of pathogens detected from all samples were compared among food categories. The pH ranges for all RTE samples were between 3.8 and 7.3. Total aerobic cell counts ranged from 2 to 6 log CFU/g. Bread, rice and fresh-cut foods showed significantly higher counts, which ranged above 4.0 log CFU/g among the samples. Two kinds of rice were above the level of the KFDA Food Code standard for Eschrichia coli. The prevalence rate of E. coli in the rice was 6.7%. For Staphylococcus aureus, one fish product and one bread-product had levels above 2 log CFU/g. Bacillus cereus counts for all samples were below the level of 3 log CFU/g. Listeria monocytogenes was not detected in the samples. Therefore, these data suggest that the primary microbial hazard factors for ready-to-eat foods and risk assessments should focus on E. coli, S. aureus, and B. cereus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1680-1687
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• 2011

This study was performed to determine the effects of pretreatment and drying methods on the quality and physiological activities of garlic powders. Fresh garlic was boiled, baked, steamed or left untreated before hot-air drying or freeze-drying. Electron-donating abilities were higher in the untreated group for each drying method. Relative EDA of baked group was 32.8%, whereas those of the boiling and steaming groups were 12.4% and 20.1%, respectively. Nitrite-scavenging effects were slightly affected by processing methods. Polyphenol content of the processing group was higher in the hot-air drying than freeze-drying group, and it was significantly highest in the untreated freeze-dried group. The value of polyphenol in the baked group was significantly higher than those of the boiling and steaming groups. Tyrosine contents of garlic powder were higher in the hot-air drying than freeze-drying group, and it was significantly highest in the untreated group of each drying method. Antimicrobial activities of the garlic powders were higher in freeze-drying group compared to the hot-air drying group. Therefore, antimicrobial activities of garlic powder were affected by heating treatments.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.209-214
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• 2012

The purpose of this study was to evaluate microbiological contamination of fresh-cut produce salads and raw cabbage toward climate change. Total aerobic bacteria, coliform and Escherichia coli were monitored to get the contamination levels and E. coli O157:H7, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes and Salmonella spp. to detect pathogens with risk of foodborne disease from samples. Collection of 360 samples (180 fresh-cut produce salads and 180 raw cabbage), including 60 samples from each area after setting 3 areas depending on annual temperature and annual rainfall. As a result, total aerobic bacteria and coliform group were different was performed areas in raw cabbage but there was no difference between areas in fresh-cut produce salads. In addition foodborne pathogens including E. coli were not isolated from fresh-cut produce salads.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.478-483
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• 2012

In order to evaluate the microbial safety of the foodstuffs and manus in regards to foodservice operations, the total of 1,051 samples of drinking waters, vegetables, and cooked foods were collected. Total viable count (TVC), coliform group, and pathogens were analyzed. Twenty five percent samples of 441 drinking waters showed high contamination of above 2 log CFU/g TVC. Twenty percent of the waters were contaminated by above one log CFU/g coliform. Forty percent of non-heated food, Moochim, were contaminated by above 5 log CFU/g TVC and 26% of Moochim were contaminated by above 2 log CFU/g coliform. Bacillus cereus and Eschericia coli were detected on boiled rice and kimchi, and B. cereus was detected with a high ratio. Therefore, the foodstuffs and manus regarding foodservice operations appear to be generally safe. However, efficient microbial control for drinking water and Moochim-style food is necessary and in particular, careful management to reduce microbial contamination should be applied to drinking water.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.41-47
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• 2003

In this study, antibacterial activity on the chicken feed supplemented with different concentrations of oriental herbal medicine feed additives (OHMFA) extract was tested for some organisms and their preventive effects on the colonization of Salmonella enteritidis (SE) in broiler chickens were examined. The growth of Bacillus cereus, listeria monocytogenes and Staphylococcus aureus was inhibited on the feed of 0.25% OHMFA and Salmonella spp. and Escherichia coli O157:H7 were inhibited on the feed containing 2.0% level. The broiler chickens fed a forage additived 1.0% level of OHMFA after inoculation of a $10^7CFU/ml$ of SE were increased in weight than the chicken fed forage without OHMFA. The incidence of SE in liver, spleen and cecum of the chickens fed forage with OHMFA was decreased on the 7th days of postinfection and SE was not isolated from the organs of the chickens after the 14th days of postinfection. Serum antibody titers of the chickens were lowered than the control group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.776-781
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• 2010

The properties and bactericidal activities of strongly acidic electrolyzed water (SEW) against food-borne pathogenic bacteria, vegetables and kitchen apparatuses were investigated. The available chlorine concentration, pH and oxidation reduction potential (ORP) of SEW were $35{\pm}1.2\;ppm$, $2.3{\pm}0.2$, and $1,140{\pm}20.4\;mV$, respectively. Five strains of food-borne bacteria with initial cell number of 7.00 log CFU/mL were not detected except Bacillus cereus after treatment with SEW for 60 sec. The numbers of Bacillus cereus were reduced to 2.08{\pm}1.00 log CFU/mL at the same condition. In vegetables, SEW treatment after washing strongly in alkalic electrolyzed water (AEW) showed better bactericidal effects than SEW only. The viable cell on stainless steel bowl ($3.86{\pm}2.49\;\log\;CFU/100\;cm^2$) and cup for water ($2.40{\pm}1.80\;\log\;CFU/100\;cm^2$) were not detected by SEW treatment (35 ppm of available chlorine concentration) for 30 sec, but survival of more than 1.00 log CFU/$100\;cm^2$ of viable cell was shown by washing of sodium hypochlorite solution at the same condition. On the other hand, the coliform group bacteria ($5.08{\pm}4.00\;CFU/100\;cm^2$) were detected on rubber globe only, and more than 2.00 log CFU/$100\;cm^2$ of viable cell and coliform group bacteria on it survived, though it was washed with flowing SEW for 30 sec.

• Food Science and Preservation
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• v.12 no.6
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• pp.558-564
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• 2005

This study was carried out to investigate the cleaning effect of sesame leaf, the sterilization effect and physicochemical properties, treated with various electrolyzed water. Initial physicochemical properties could be kept more than 1 month in electrolyzed oxidizing water(EW-1) of diaphragm type and 15 days in electrolyzed water(EW-2 and EW-3) of non-diaphragm system, there was no significant difference by storage temperature. 4 kinds of microorganism (initial total counts, $10^7\~10^9$ CFU/mL) were sterilized within $0.5\~1$ minutes by electrolyzed water. In fresh sesame leaves, total viable cell count and coliform group in the treatment of electolyzed water were decreased to about $2\~3$ log scale comparing non-treated ones. Especially Bacillus cereus was not detected until 13th day when treated with EW-l. Decaying ratio of sesame leaf appears on day 6 of storage in the untreated but the treatments of electrolyzed water has no sign until day 10 of storage. Change in color difference(${\Delta}E$) during storage was observed the treatments of electrolyzed low-alkaline water(EW-2) and electrolyzed neutral water(EW-3) were very desirable at the level $1\~2$ after day 13 of storage comparative to the untreated Change of Chlorophyll content was biggest decreased to 6.8 $mg\%$ on the untreated and decreased least to 8.35 $mg\%$ on EW-3 treated group on 13th day from initial value of $9.0\~10.3\;mg\%$ The overall sensory evaluation appeared most acceptable in the treatments of EW-2 and EW-3.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1049-1056
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• 2012

The antioxidant activities and antibacterial activities of grape pomace fermented using a variety of useful microorganisms were analyzed. There were several experimental groups: the control, with non-fermented grape pomace; the BS group, fermented by Bacillus subtilis; the LP group, fermented by Lactobacillus plantarum; the LC group, fermented by L. casei; the CU group, fermented by Candida utilis; the Y1 group, fermented by Saccharomyces cerevisiae strain CHY1011; the Y2 group, fermented by S. cerevisiae strain ZP 541; and the M group, fermented by a mixed strain culture of LP, LC, and CU. The yield of freeze-dried powder of fermented grape pomace by BS, LP, LC, CU, Y1, Y2, and M was 10.74%, 9.36%, 8.68%, 9.55%, 7.49%, 9.60%, and 9.71% w/w, respectively. The total polyphenol content of grape pomace showed the highest value in the control, but the fermented LP had higher total polyphenol content than those of other fermented grape pomace. The control and fermented LP had 0.16 mg/mL and 0.28 mg/mL as $IC_{50}$ values on DPPH radical scavenging, and 0.22 mg/mL and 0.53 mg/mL of ABTS radical scavenging activity, respectively. The FRAP value (5 mg/mL) showed the highest value on fermented LP (2.44 mM) but did not show a significant difference in the control group (12.27 mM). The fermented LC showed the antimicrobial activities against B. cereus (11 mm), B. subtilis (11 mm), Staphylococcus aureus (12 mm), Escherichia coli (12 mm), Enterobacter cloacae (10.5 mm), Salmonella enterica (11.5 mm), and Pseudomonas aerugionsa (11 mm) at 5 mg/disc, but the control and other fermented grape pomace did not show antimicrobial activities. Thus, fermented grape pomace by LC is shown to be producing a material that has antibacterial activity. In conclusion, grape pomace fermentation using various lactic acid bacteria strains showed excellent effects in promoting the production of functional materials. Especially, using L. casei exhibited an increase in antibacterial activity, and using L. plantarum exhibited antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.695-702
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• 2017

This study was carried out to investigate the effects of seed vinegar on antioxidant activity and antimicrobial activities of concentrated blueberry vinegar (CBV). Of the nine strains of yeast and six strains of acetic acid bacteria provided by the Microbial Institute for Fermentation Industry, each strain of yeast (Saccharomyces cerevisiae SRCM 100610, showing the highest ethanol content) and acetic acid bacteria (Acetobacter pasteurianus SRCM 101342, showing the highest total acidity) was selected for production of CBVs. Sugar content, pH, total acidity, total phenolic content (TPC), and browning intensity (280 nm and 420 nm) in CBVs using concentrated blueberry juice were $11.05{\sim}12.70^{\circ}Brix$, 2.63~2.98, 1.65~5.72%, 3.03~4.24 mg/mL, 0.95~1.50, and 0.11~0.20, respectively. Sugar content and total acidity of CBVs increased upon addition of seed vinegar, whereas pH, TPC, and browning intensity decreased. Of all CBVs with various additions of seed vinegar, the control showed the lowest $EC_{50}$ values in DPPH radical scavenging assay, ABTS radical scavenging assay, and reducing power (23.80, 19.48, and 79.21 dilution factor, respectively), whereas the 40% seed vinegar group showed the highest clear zone diameter values for Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus (4.31, 4.59, 5.81, and 3.97, respectively). Antioxidant activities of CBVs were closely correlated with their TPC, browning intensity at 280 nm, pH, and total acidity values, showing correlation determination coefficient ($R^2$) values higher 0.82. However, antimicrobial activities of CBVs were closely correlated with their pH and total acidity values, showing higher $R^2$ values more than 0.92. These results suggest that CBVs using concentrated blueberry juice, S. cerevisiae SRCM 100610, and A. pasteurianus SRCM 101342 may be useful as potentially functional foods for enhancing health.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.1-12
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• 2019

The health benefits associated with consumption of fresh produce have been clearly demonstrated and encouraged by international nutrition and health authorities. However, since fresh produce is usually minimally processed, increased consumption of fresh fruits and vegetables has also led to a simultaneous escalation of foodborne illness cases. According to the report by the World Health Organization (WHO), 1 in 10 people suffer from foodborne diseases and 420,000 die every year globally. In comparison to other processed foods, fresh produce can be easily contaminated by various routes at different points in the supply chain from farm to fork. This review is focused on the identification and characterization of possible sources of foodborne illnesses from chemical, biological, and physical hazards and the applicable methodologies to detect potential contaminants. Agro-chemicals (pesticides, fungicides and herbicides), natural toxins (mycotoxins and plant toxins), and heavy metals (mercury and cadmium) are the main sources of chemical hazards, which can be detected by several methods including chromatography and nano-techniques based on nanostructured materials such as noble metal nanoparticles (NMPs), quantum dots (QDs) and magnetic nanoparticles or nanotube. However, the diversity of chemical structures complicates the establishment of one standard method to differentiate the variety of chemical compounds. In addition, fresh fruits and vegetables contain high nutrient contents and moisture, which promote the growth of unwanted microorganisms including bacterial pathogens (Salmonella, E. coli O157: H7, Shigella, Listeria monocytogenes, and Bacillus cereus) and non-bacterial pathogens (norovirus and parasites). In order to detect specific pathogens in fresh produce, methods based on molecular biology such as PCR and immunology are commonly used. Finally, physical hazards including contamination by glass, metal, and gravel in food can cause serious injuries to customers. In order to decrease physical hazards, vision systems such as X-ray inspection have been adopted to detect physical contaminants in food, while exceptional handling skills by food production employees are required to prevent additional contamination.