• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.197-203
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• 2019

This study was carried out to investigate the effect of chlorine water and plasma gas treatment on the quality and microbial control of Latuca indica L. baby Leaf during storage. Latuca indica L. baby leaves were harvested from a plant height of 10cm. They were sterilized with $100{\mu}L{\cdot}L^{-1}$ chlorine water and plasma-gas (1, 3, and 6hours), and packaged with $1,300cc{\cdot}m^{-2}{\cdot}day^{-1}{\cdot}atm^{-1}$ films and then stored at $8{\pm}1^{\circ}C$ and RH $85{\pm}5%$ for 25days. During storage, the fresh weight loss of all treatments were less than 1.0%, and the carbon dioxide and oxygen concentrations in packages were 6-8% and 16-17%, respectively for all treatments in the final storage day. The concentration of ethylene in the packages fluctuated between $1-3{\mu}L{\cdot}L^{-1}$ during the storage and the highest concentration of ethylene was observed at 6 hours plasma treatment in the final storage day. The off-odor of all treatments were almost odorless, the treatments of chlorine water and 1 hour plasma maintained the marketable visual quality until the end of storage. Chlorophyll content and Hue angle value measured at the final storage day were similar to those measured before storage in chlorine water and 1 hour of plasma treatments. E. coli was not detected immediately after sterilization in all sterilization treatments. After 6 hours of plasma treatment, the total bacteria fungus counts were lower than the domestic microbial standard for agricultural product in all sterilization treatments. The total aerobic counts in the end storage day increased compared to before storage, whereas E. coli was not detected in all sterilization treatments. The sterilization effect against bacteria and fungi was the best in chlorine water treatment. Plasma treatment showed sterilization effects, but within a prolonged period of time. In addition, the sterilization effect decreased gradually. These results suggest that chlorine water and plasma treatment were effective in maintaining Latuca indica L. baby Leaf commerciality and controlling microorganisms during postharvest storage.

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.222-227
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• 2007

The effects of chlorine dioxide ($ClO_2$) treatment on the quality changes of pork and beef were examined. Pork belly and beef tenderloin samples were treated with 30, 50, and 100 ppm of $ClO_2$ solution, respectively, and stored at $4{\pm}1^{\circ}C$. The $ClO_2$ treatment of pork and beef during storage decreased total aerobic bacteria, yeast, and mold counts with increasing concentration of $ClO_2$. The total aerobic bacterial counts for the pork belly treated at 100 ppm of $ClO_2$ increased from 1.48 log CFU/g immediately following treatment to 4.73 log CFU/g after 10 days, while the control increased from 2.19 log CFU/g to 6.22 log CFU/g. For the beef tenderloin, the total aerobic bacterial counts increased from 3.98 log CFU/g to 5.97 log CFU/g after 10 days, and a $ClO_2$ treatment at 100 ppm resulted in an increase from 3.13 log CFU/g to 4.73 log CFU/g. The pH and volatile basic nitrogen (VBN) values of the $ClO_2-treated$ pork and beef, as well as the control groups, increased during storage, and there were no significant changes among the treatments. The thiobarbituric acid reactive substance (TBARS) values of the $ClO_2-treated$ samples were slightly higher than those of the control. Sensory evaluation results showed that the pork and beef samples were not acceptable at day 8 and 6 of storage, respectively. These results indicate that $ClO_2$ treatment could be useful in improving microbial safety and quality of both pork and beef.

• Food Science and Preservation
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• v.20 no.3
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• pp.323-329
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• 2013

Strawberries are among the leading ready-to-eat agricultural products that have superior taste and nutrition. Thus, consumer concerns about the safety of eating strawberries are growing. To evaluate the contamination levels of strawberries according to their cultivation methods (nutriculture, pesticide-free culture and organic farming) and parts [fruit (flesh), stalk (pedunle) and leaf (calyx)], 1,020 parts of strawberry samples were collected at 12 farms in Nonsan-si and quantitatively or qualitatively examined for the indicators of food safety and food poisoning bacteria. The total aerobic bacteria count in the whole samples was 2.3~6.8 ${\log}_{10}$ CFU/g, and coliform bacteria were detected in 14.2% of the whole samples with a contamination level range of 2.1~4.5 log CFU/g. E. coli were detected in 0.9% of the whole samples with a contamination level range of 2.1~2.8 log CFU/g. The analysis of the bacterial levels according to the cultivation methods showed that the total aerobic bacteria and coliform counts were higher in the strawberries that were grown via organic farming than in those that were grown via nutriculture and pesticide-free culture. However, the E. coli counts of the strawberries that were grown via organic farming and via pesticide-free culture were similar and differed from that of the strawberries that were grown via nutriculture. The analysis of the contamination levels according to the parts of the strawberries showed that the total aerobic bacteria, coliform and E. coli counts of the fruits, stalks and leaves of the strawberries did not significantly differ. Staphylococcus aureus was detected in two organically grown strawberries, but Salmonella spp., Listeria monocytogenes and E. coli O157:H7 were not detected in the whole samples. These results show that the bacterial contamination levels of the strawberries differed based on their cultivation methods. Thus, a suitable method of reducing the bacterial contamination levels of strawberries according to their farming methods is needed.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.560-564
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• 2012

This study was undertaken to assess the microbiological quality and prevalence of pathogens in organic vegetables produced in Korea. A total of 189 organically grown vegetable samples (perilla leaf 50, lettuce 50, tomato 39, cucumber 50) were analyzed for the presence of aerobic plate count, Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, and Yersinia enterocolitica. The total aerobic plate counts were in the range of 4.2 to $7.7log\;CFU\;g^{-1}$ for perilla leaf, 5.0 to $8.0log\;CFU\;g^{-1}$ for lettuce, 4.0 to $7.5log\;CFU\;g^{-1}$ for tomato, and 6.6 to $8.6log\;CFU\;g^{-1}$ for cucumber. The highest counts were found in cucumber. E. coli O157:H7, Salmonella spp., S. aureus, L. monocytogenes, and Y. enterocolitica were not detected from any organically grown vegetable samples. This research suggests that continuous monitoring in organic vegetables is required to improve fresh produce safety.

• Food Science and Preservation
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• v.20 no.5
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• pp.699-704
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• 2013

Buckwheat Soksungjang (BS) is a bealmijang manufactured with buckwheat and soybeans. We manufactured BS using Bacillus subtilis HJ18-4 (HJ18-4), which has high enzyme activities and antibacterial effects. HJ18-4 was inoculated in a different process during the BS manufacturing, which was the meju-making time (Treat 1), and the salt water time was added (Treat 2). The physiochemical and microbial characteristics of the BS were analyzed. As a result, the total aerobic counts (7~8 log CFU/mL) in the BS increased after 15 days of fermentation. Especially, Treat 1 showed higher total aerobic counts and amino-type nitrogen (65.38~202.52 mg%) than Treat 2. During the BS fermentation, the reduction of the sugar contents and the enzyme (protease and amylase) activities decreased. In the relative quantitative expression level of PlcR, Treat 1 did not show toxin gene expressions at the end of the fermentation on Day 23. Treat 1 showed suitable B. cereus physiochemical quality characteristics and inhibition effects. When the modified-form type of fermented soybean paste was manufactured with a single starter, it could not reproduce the natural fermentation quality. These results suggest that the addition of a starter (HJ18-4) in the Meju manufacturing process could enhance the quality characteristics of the manufactured BS via natural fermentation and by suppressing B. cereus.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.122-128
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• 2005

Contamination levels of total aerobic bacteria, coliforms, Esherichia coli, Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes of Kimbab and its main ingredients sampled from general and specialized restaurants were compared. Total aerobic bacteria and coliform counts of Kimbab samples from both restaurant types were not significantly different (p>0.05), showing approximately $4\;to\;6\;log_{10}CFU/g$. E. coli counts were significantly higher in kimbab from general restaurants ($65%:\;0.7-2.6\;log_{10}CFU/g$) than those from specialized ones ($8.33%:\;0.70log_{10}CFU/g$), whereas those of S. aureus and B. cereus were not significantly different (p>0.05). L. monocytogenes was not detected in all Kimbab samples. These results indicate hygiene of Kimbab and its main ingredients are deleterious. Contamination levels of pathogens determined in the present study may be used as primary data for microbial risk assessment.

• Food Science and Preservation
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• v.14 no.5
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• pp.487-491
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• 2007

This study was conducted to investigate the effect of treatment with squeous chlorine dioxide and hot water on the germination of radish (Raphanus sativus L.) seeds, and reduction of microbial load on the seeds. Increases in treatment and the concentration of aqueous chlorine dioxide in water resulted in increasing reductions in the counts of total aerobic microbes. Seeds treated with aqueous chlorine dioxide (100 ppm/20min, 200ppm/20min) showed about a 10-fold decrease in microbial loads. Germination of seeds was not adversely affected by any treatment tested, although the germination rate of seeds in the group treated at $55^{\circ}C$ for 20 min was reduced by 10% compared to that of control. Combined treatment with hot water and aqueous chlorine dioxide yielded better out comes in both microbial reduction and seed germination rate than did single treatments. A combined treatment with 100 ppm aqueous chlorine dioxide and hot water($45^{\circ}C$ or $50^{\circ}C$) resulted in about a 100-fold decrease in microbial load whereas germination rate showed only a slight increase to $97.0{\sim}97.7%$. Total aerobic microbial counts in radish seeds were decreased by aqueous chlorine dioxide and hot water treatment in the order. aqueous $CIO_2$+ hot water > aqueous $CIO_2$ > chlorinated water > hot water > control.

• Food Science of Animal Resources
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• v.24 no.2
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• pp.115-120
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• 2004

This study was carried out to investigate the effect of the scalding temperature at slaughtering process on meat quality and storage properties of chicken. The yellowness (b$\^$*/ value) of skin decreased at high scalding temperature (65-67$^{\circ}C$) and WHC (water holding capacity) increased from 67.04％ at low temperature (53-55$^{\circ}C$) to 69.26％ at high temperature. WBS (Warner-Bratzler Shear force) significantly increased from 1.70kg/0.5inch$^2$ to 2.54kg/0.5inch$^2$ as the scalding temperature increased (p＜0.05). TBARS (Thiobarbituric Acid-Reactive Substance) values were 0.25mgMA/kg at low temperature, 0.24mgMA/kg at middle temperature (59-61$^{\circ}C$) and 0.27mgMA/kg on 3 days of storage. Total aerobic counts (TPC) were 4.99 logCFU/mL at low temperature, 4.88 10gCFU/mL at middle temperature and 4.05 logCFU/mL. Although TPC was decreased as the scalding temperature increased. The detection rate of feather at carcass inspection was low as the scalding temperature increased and the detection rate of large feather (＞lcm) was not significantly different between middle temperature and high temperature. Exposed flesh was severe as the scalding temperature increased. In conclusion, meat color and physical properties of chicken were acceptable when the carcasses were scalded at low temperature, but they were microbiologically susceptible and uneasy to remove the feather. The yellowness (b$\^$*/ value) of skin decreased at high scalding temperature, and total aerobic counts (TPC) were decreased as the scalding temperature increased, and easy to remove the feather.

• Food Science and Preservation
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• v.23 no.7
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• pp.913-922
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• 2016

The aim of this study was to develop a new salting condition that included added maltodextrin (MD) and grape seed extract (GSE) to ensure the microbiological safety and quality of salted shredded Korean cabbage. Response surface methodology (RSM) was used to analyze the effects of four independent variables (NaCl concentration, salting duration, MD concentration, and GSE concentration). The following response variables were evaluated: reduction in total aerobic bacteria, yeast, and mold counts; weight loss and salt content; and taste, texture, and overall acceptability of salted shredded Korean cabbage. The optimal salting conditions include a combination of 10.09~10.32% NaCl, 9.45~10.00% MD, and 234~300 ppm GSE in a ternary salting solution and a salting duration of 5.68~5.94 hr. This optimal combination reduced total aerobic bacterial and yeast/molds counts by 3.33 and 1.45 log CFU/g, respectively, while maintaining high sensory scores for taste, texture, and overall acceptability of the salted shredded Korean cabbage. In addition, the optimal conditions yielded more acceptable weight loss and salt content characteristics. The results suggest that use of the optimized combination of salting conditions can improve the microbiological safety and quality of salted shredded Korean cabbage used for commercial kimchi production.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.94-101
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• 2018

Although Kimchi has health benefits, food poisoning associated with consumption of Kimchi has been frequently reported. Accordingly, microbiological properties of Kimchi (100 samples) and washing effects on microbial reduction against its ingredients (200 samples) were examined. Total aerobic bacteria, coliforms, Escherichia coli, Bacillus cereus, and Clostridium perfringens were quantified. In addition, B. cereus, Salmonella spp., Enterohemorrhagic E. coli, C. perfringens, Campylobacter jejuni/coli, Staphylococcus aureus, Vibrio parahaemolyticus, Listeria monocytogenes, and Yersinia enterocolitica were analysed qualitatively. Total aerobic bacteria count was approximately 1.4-9.0 log CFU/g, which were highest in ginger (8.8 log CFU/g), and Chonggak Kimchi (9.0 log CFU/g). The range of coliform counts detected in all raw materials was 0.5-7.3 log CFU/g and ginger showed the greatest number 7.3 log CFU/g among others. Contamination was decreased to 0.2-3.2, 0.3-2.7, and 1.0-3.9 log CFU/g for total aerobic bacteria, coliforms, and B. cereus, respectively, after washing. Minimising microbial contamination in Kimchi ingredients is necessary to ensure the safety of Kimchi. These results indicate that washing is a useful method to reduce bacterial contamination in Kimchi.