• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1438-1446
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• 2016

The objectives of this study were to investigate the effects of superheated steam (SHS) treatment on the physicochemical and microbial properties of garlic. The garlic was treated by SHS at temperatures of 100, 150, 200, 250, 300, and $350^{\circ}C$ for 60 s. The moisture content of raw garlic was lower than that of SHS-treated garlic. The total thiosulfinate and pyruvate contents were dramatically reduced by SHS treatments. The antioxidant activities of garlic measured by ferric reducing/antioxidant power, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging assay, and total phenolics content decreased by SHS. The major volatile sulfur compounds of garlic such as diallyl disulfide, allicin, allyl sulfide, diallyl sulfide, and diallyl trisulfide were significantly reduced by SHS. The antimicrobial effects of raw garlic were stronger than those of SHS-treated garlic against three strains of bacteria, including Staphylococcus aureus, Escherichia coli, and Bacillus cereus. However, total aerobic bacteria in garlic were dramatically reduced by SHS from 8.6 to 2.9 log CFU/g. The results from the sensory evaluation show that SHS treatment of garlic above $200^{\circ}C$ provides better acceptably due to reduction of off-flavor and pungency of garlic. These results suggest that superheated steam treatment can used as an efficient process for reducing garlic off-flavor and pungency.

• 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.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.91-97
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• 2011

This study was performed to assess the microbiological quality and potential health risk of fresh-cut produce and organic vegetables sampled from supermarkets and department stores in Korea. A total of 96 samples comprised three types of fresh-cut produce (sprouts, mixed-vegetables, fruit) and three types of organic vegetables (lettuce, perilla leaf, green pepper). The samples were analyzed for total viable cell counts, coliforms, Enterobacteriaceae, Escherichia coli, Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus, Bacillus cereus, and Staphylococcus aureus. The microbiological counts of fruit were very low. Sprouts were highly contaminated by total viable cell counts ($8.3{\pm}0.57$ log CFU/g), Enterobacteriaceae ($7.1{\pm}0.76$ log CFU/g), and coliforms ($4.9{\pm}0.40$ log MPN/g), and showed a high incidence level of B. cereus ($2.9{\pm}0.48$ log CFU/g). Of the fresh-cut produce analyzed, six (13.6%) mixed-vegetable salads were E. coli positive. S. aureus was detected in only one sprout sample and one mixed-vegetable salad, and its contamination levels were under 2 log CFU/g, which is appropriate for Korean standards (<3 log CFU/g) of fresh-cut produce. Of the organic vegetables, lettuces were highly contaminated by total viable cell counts ($6.4{\pm}0.74$ log CFU/g), Enterobacteriaceae ($5.7{\pm}0.98$ log CFU/g), and coliforms ($3.7{\pm}1.72$ log MPN/g). Two (13.6%) organic lettuce and one (7.1%) perillar leaf sample were E. coli positive, and S. aureus was detected in one lettuce and two perilla leaf samples. Salmonella spp., Vibrio parahaemolyticus, and Listeria monocytogenes were not detected in any of the fresh-cut produce or organic vegetables analyzed.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.329-334
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• 2010

Escherichia coli O157:H7 causes hemolytic uremic syndrome and hemorrhagic colitis in humans. The objectives of this study were to produce monoclonal antibody(MAb) against E. coli O157:H7 and to develop an enzyme linked immunosorbent assay(ELISA) for the rapid detection of E. coli O157:H7 in agri-stockbreeding. The characterization of MAb produced from hybridoma cell (HKEC 4G8-5) was validated by ELISA and Western blot. The produced MAb was specific to E. coli O157:H7 and showed weak cross-reaction to Staphylococcus aureus. The detection limit of ELISA based on 4G8-5 MAb was $10^5\;cell/mL$. Although the ELISA could not detect E. coli O157:H7 in the meat and sprout samples inoculated with $1{\times}10^1\;cell$/10 g without enrichment, the same samples after enrichment for 6 hr were confirmed to be positive by ELISA. These results indicated that the ELISA combined with short enrichment (6 hr) is useful tool for rapid screening of E. coli O157:H7 in various samples.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.173-180
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• 2017

This study evaluated the characteristics of rice cookies with varying amounts (0, 250, 500, and 750 mg) of dandelion complex powder. Dandelion powder is considered a functional food with skin-moisturizing and atopic skin improvement effects by KFDA. Quality characteristics of AF343 and rice cookies were measured by determining antimicrobial activities, physical characteristics, sensory evaluation values, and antioxidant activities. An antibiotic susceptibility test of the powder showed positive activities in Escherichia coli (O157:H7), Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes. Rice cookie containing 250-500 mg powder showed significantly increased antioxidant activities compared to controls (p<0.05). However, sensory intensities between the two sample groups were not significantly different. Thus, rice cookies containing 250-500 mg dandelion complex powder were successfully developed to improve antioxidant and antimicrobial qualities. These products may attract the attention of health-conscious consumers in the highly competitive cookie industry.

• Journal of Food Hygiene and Safety
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• v.21 no.3
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• pp.189-195
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• 2006

This research was designed to evaluate the nutritional an microbiol quality assessment of Chungmukimbab purchased from market in Tongyeoung area. Contents of calories, calcium, iron, thiamin and riboflavin in ordinary kimbab and Chungmukimbab were lower than the recommended levels of Korean adult men. So, We suggested that a fruit, beverage and ffod stuff were supplemented to maintain nutritional balance. Total aerobic bacteria and coliform group of just prepared ordinary kimbab and Chungmukimbab samples from market were not significantly different, showing approximately $5.50{\pm}0.38 log_{10} CFU/g,\;2.10{\pm}0.47log_{10}MPN/100g$ in ordinary kimbab, $5.61{\pm}0.42log_{10}CFU/g,\;1.75{\pm}0.34 log_{10} MPN/100g$ in Chungmukimbab, respectively. Total aerobic bacteria of law ingredients of chungmukimbab sample were 3 to $4 log_{10}CFU/g$ in kimbab, seasoning squid and radish roots kimchi, 4 to $5 log_{10}CFU/g$ in boiled fish paste. The coliform groups were 1 to $2 log_{10}$ MPN/100 g in kimbab, seasoning squid and radish roots kimchi, 2 to $3 log_{10}$ MPN/100g in boiled fish paste. Detection rate of E. coli and Staphylococcus aureus counts were 10.0, 12.5% in Chungmu-kimbab, 15.0, 10.0% in seasoning squid, 0, 10.0% in radish roots kimchi respectively, not detected in boiled fish paste samples. During storage at $15^{\circ}C$ for 24 hours, total aerobic counts and coliform groups in ordinary kimbab and Chungmukimbab were increased by the 1.94, $0.97log_{10}CFU/g$, 0.60, 0.72 log10 MPN/100g respectively. Total aerobic counts of Chungmukimbab ingredients increased $0.83{\sim}l.33 log_{10}CFU/g$ at different time

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.203-208
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• 2011

This study was to evaluate the efficacy of sanitizer concentrations and treatment time against two major toad-borne pathogenic microorganisms such as Escherichia coli and Staphylococcus aureus on a stainless steel surface. As a result, stainless steel, treated with 100 ppm of chlorine showed reduction of E. coli(1.56, 1.49, 1.95 log cfu/25 $cm^2$) and S. aureus(0.49, 0.88, 1.27 log cfu/25 $cm^2$) after 0, 5 and 10 min, but none was not detected in treatment with 200 ppm. The population of E. coli(0.73, 0.90, 1.55 log cfu/25 $cm^2$) and S. aureus(0.37, 1.00, 1.45 log cfu/25 $cm^2$) reduced in 35.5% ethanol treated group, but none was not detected in treatment with 70%. The population was reduced E coli(0.28, 0.64, 1.07 cfu/25 $cm^2$) and S. aureus(0.53, 0.87, 0.99 log cfu/25 $cm^2$) by treatment with 45.5 ppm of hydrogen peroxide, but none was not detected in treatment with 91 ppm. Quarternary ammonium compound with 100 ppm was reduced E. coli(0.82, 1.62, 1.71 log cfu/25 $cm^2$) and S. aureus(0.46, 0.93, 1.38 log cfu/25 $cm^2$), but none was not detected in treatment with 200 ppm. Predictive models of sterilization for all 4 disinfectants were suitable to use with $r^2$ value of higher than 0.94. These models may be of use to food services and manufacture of safe products by controlling E. coli and S. aureus without the need for further detection of the organisms.

• 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.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.181-188
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• 2014

The objective of this study was to analyze the microbiological hazards of Astragalus membranaceus Bunge on the post-harvest processing. Samples from processing equipments (cleaner, water, cart, table, tray and packaging machine), personal hygiene (hand) and harvested crops (before washing, after washing, after sorting, and after drying) were collected from four farms (A, B, C, and D) located in Chungchengbuk-do, Korea. The samples were analyzed for sanitary indication bacteria and pathogenic bacteria. First, total aerobic bacteria and coliform in processing facilities were detected at the levels of 0.93~4.86 and 0.33~2.28 log CFU/$100cm^2$ and/mL respectively. In particular, microbial contamination in hand (5.43~6.11 and 2.52~4.12 log CFU/Hand) showed higher than processing equipments. Among the pathogenic bacteria, Bacillus cereus was detected at the levels of 0.33~2.41 log CFU/$100cm^2$, 1.48~3.27 log CFU/Hand and 0.67~3.65 log CFU/g in equipments, hands, and plants and Staphylococcus aureus were detected in cleaner, table, hand and harvested crops (before washing and after sorting) by qualitative test. Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella spp. were not detected. These results indicated that personal hygiene and processing equipments should be managed to reduce the microbial contamination of A. membranaceus Bunge. Therefore, management system such as good agricultural practices (GAP) criteria is needed for hygienic agricultural products.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.279-285
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• 2013

To establish sample preparation method for detection of food-borne pathogens from lettuce, perilla leaves, cucumber, pepper, and cherry tomato, the influences of diluent composition, processing time, and proportion of diluent to sample were examined. Each produce was inoculated with 6.0 log $CFU/cm^2$ of Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus. Each produce was treated with 0.1% peptone water, and D/E neutralizing broth. Processing time of produce was 30, 60, 90, and 120s, and the proportion of diluent to sample was 2 : 1, 4 : 1, 9 : 1, and 19 : 1. The number of bacteria after treatment of D/E neutralizing broth was higher than that of 0.1% peptone water (P<0.05). In cherry tomato, the population of S. typhimurium recovered from treated with D/E broth was higher than that recovered from treated with 0.1% peptone water by 1.05 log $CFU/cm^2$ (P<0.05). No difference in numbers of pathogens was observed in processing time. Optimum proportion of diluent to perilla leaf, iceberg lettuce, cucumber, green pepper, and tomato was 9 : 1, 4 : 1, 2 : 1, 2 : 1, and 2 : 1, respectively. These data suggest that D/E neutralizing broth should be recommend as diluent, and the diluent volume applied to produce should be determined in proportion to produce surface area per weight (g).