• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.151-159
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• 1991

As a part of investigation on causes of drop in egg production in domestic chicken breeding farm, bacteriological contamination on air, feed, drinking water and artificial insemination instruments of randomly selected three farms was surveyed. Total bacterial population in the air was very high in all of the chicken houses tested and was not significantly different among these farms . However, total bacterial counts in the air of the problem house having egg drop problem and colibacillosis was higher than normal house within the problem farm. Bacterial population in the assorted feed was low before or after administration on the normal farm while it was much more increased after administration than before administration on the problem farm. Bacterial population of the drinking water in the source of water supply was very low and has no differences among farms tested. Also, bacterial population in the normal farm was not significantly different between source of water supply and after administration. However, population of total bacteria and coliform bacteria after administration was increased. Bacterial population was much higher in the artificial insemination instrument of problem farm than normal farm. However, this bacterial population in the problem farm was decreased to those of normal farm after these instruments were sanitized.

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.31-43
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• 2014

This experiment evaluated the interaction effect of extreme heat diet(EHD), inverse lighting, and cool water on the growth performance of broiler chickens under extreme heat stress. There were 4 experimental groups (T1: EHD 1, 10:00-19:00 dark, 19:00-10:00 light, cold water $9^{\circ}C$; T2: EHD 2, 10:00-19:00 dark, 19:00-10:00 light, cold water $9^{\circ}C$; T3: EHD 1, 09:00-18:00 dark, 18:00-09:00 light, cold water $14^{\circ}C$; T4: EHD 2, 09:00-18:00 dark, 18:00-09:00 light, cold water $14^{\circ}C$), each group composed of 25 broilers and the experiment was repeated 3 times. EHD 1 contained soybean oil, molasses, methionine and lysine. EHD 2 contained all nutrients of EHD 1 and vitamin C additionally. As a result, T1 and T2 displayed higher body weight increase and diet intake compared to T3 and T4 (p<0.05). The weights of their liver and gizzard were similar but the weights of the thymus and bursa F were higher for T1 and T2 compared to that of T3 and T4 (p<0.05). It was observed that T1 and T2 displayed higher concentrations of blood triglyceride, total cholesterol, HDL-C and blood sugar compared to that of T3 and T4 but LDL-C level was higher for T3 and T4 compared to that of T1 and T2 (p<0.05). T1 and T2 displayed higher levels of immunity substances such as IgG, IgA and IgM compared to T3 and T4 but the blood level of corticosterone displayed to be lower for T1 and T2 compared to T3 and T4 (p<0.05). The T1 and T2 contained a higher amount of fecal lactobacillus compared to that of T3 and T4 but the T3 and T4 contained a higher amount of fecal E. coli, total aerobic bacteria, coliform bacteria compared to that of T1 and T2 (p<0.05). T1 and T2 displayed higher concentrations of cecal acetic acid, propionic acid and total short chain fatty acids compared to T3 and T4 but T3 and T4 displayed higher concentrations of butyric acid, isobutyric acid, valeric acid and isovaleric acid compared to T1 and T2 (p<0.05). These results have been observed that broiler chickens exposed to extreme heat stress with feeding EHD, inverse lighting and cold water would improve blood lipid, and elevate the production of immunity substance, beneficial microorganisms, and short chain fatty acids. This provision would also reduce the blood sugar consumption rate as energy sources and these effects will improve the growth performance of the broilers exposed to extreme heat.

• Food Science and Preservation
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• v.22 no.2
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• pp.232-240
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• 2015

This study investigated the microbiological and nutritional characteristics of bimonthly radish sprouts purchased at a local market. The total bacteria and coliform measurements were highest in summer (June and August) and lowest in winter (February and December). The total phenol content was $16.82{\pm}0.69GAEmg/g$, and it did not significantly differ during the investigation period. The total carotenoid contents were highest in February (about $12.81{\pm}0.49$ ${\beta}$-carotene mg/g) and lowest in April (about $8.09{\pm}1.01$ ${\beta}$-carotene mg/g). However although total glucosinolates content differ between the total crude glucosinolate and the sum of the individual glucosinolates, it was highest in December. The individual glucosinolates were found to have been gucoraphenin, glucoerucin, glucobrassicin and gluconasturtiin in radish sprouts via HPLC analysis. The purchasing time of the glucoraphenin content did not significantly differ. The measured glucoerucin was highest in February and lowest in October. The gucobrassicin and gluconasturtiin were higher in summer than in winter, but did not significantly differ. The antioxidant activity (i.e., the $IC_{50}$ values of the DPPH radical scavenging) was highest in February. In conclusion, the microbial contamination, total carotenoids, and antioxidant activity changed according to the purchasing season, but the total phenolic compounds and total glucosinolates were maintained regardless of the time in the radish sprouts.

• Korean Journal of Agricultural Science
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• v.6 no.2
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• pp.158-165
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• 1979

These studies were carried out to investigate the freshness and bacteria of ultra high temperature processed market milks which treated and distributed in four districts: Kwangju, Daejon, Sungwhan and Seoul, and to elucidate their keeping qualities when stored in refrigerator and at room temperature. Various samples taken from the four districts were tested and the results obtained were as follows. 1. Samples from three districts retained acidities fit for standard for 9 days and those from one district for 5 days when stored at $4^{\circ}C$. However, the periods were shortened to 1 day for samples of the three districts and to same day for those of one district when stored at $20^{\circ}C$. 2. Negative results were obtained from alcohol and boiling tests upto 10 days for samples of the three districts and upto 6 to 7 days for those of one district when stored at $4^{\circ}C$. But positive results were recorded after 2 days for samples of the three districts and after 1 day for those of one district when stored at $20^{\circ}C$. 3. Total viable number of organisms did not exceed the standard limit upto 10 days for sample of one district, up to 7 days for those of two districts and upto 2 days for those of the other when stored at $4^{\circ}C$. But in case of storage at $20^{\circ}C$, samples of one district maintained viable titre below the limit for 1 day and samples of three districts for same day. 4. Initial number of psychrophilic were $4.8{\times}10^3/ml$ on an average. This titre was increased to $6.4{\times}10^7/ml$ gradually during 10 days when stored at $4^{\circ}C$, and to $5.2{\times}10^7/ml$ during 2 days. when stored at $20^{\circ}C$. 5. Number of thermoduric bacteria were below $10^2/ml$ for 10 days in samples of three districts and for 6 days in those of the other when stored at $4^{\circ}C$. However, in case of storage at $20^{\circ}C$, the titre exceeded $10^2/ml$ after 1 day in samples of three districts. 6. No coliform bacteria were detected in all samples from the four districts.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.3
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• pp.127-137
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• 2007

To confirm whether or not the Electrochemical Disinfection System (EDS) meet with the D-2 regulation established by IMO (International Maritime Organization), the biological treatment efficacy of the EDS was assessed using three groups of natural marine plankton (bacteria, $10-50\;{\mu}m$ and $>50\;{\mu}m$ sized organisms). Influent water was passed through the EDS under the flow velocity ($23.8\;m^3/hr$) and test design was consisted of control (no treatment) and experimental (10 ppm and 30 ppm) condition for total residual chlorine (TRC). And the biological condition of the influent water followed the standards established by the guidelines for the approval of ballast water management systems. The disinfection efficacy of the $10-50\;{\mu}m$ sized organisms (phytoplankton) was assessed by three kinds of measurements using photomicroscope, epifluorescence microscope and fluorometer (fumer Designs 10-AU). After being passed through the EDS, all motile phytoplankton lost their motility under photomicroscope, the colour of chlorophyll fluorescence fumed from red into green under epifluorescence, and the high chlorophyll fluorescence (Expt. 1: 6.95, Expt. 2: 7.11) detected by fluorometer decreased into value not detected. These results indicated phytoplankton community was totally killed after electrochemical disinfection treatment. Survivorship of the larger organisms than $50\;{\mu}m$ was determined based on the appendage's movement under a stereomicroscope. Natural assemblage collected from ambient seawater was killed shortly after being passed through the EDS, whereas some Artemia remained alive. However, no live Artemia was found after 24 hour further exposure to each TRC concentration (10 and 30 ppm) under darkness. After electrochemical treatment, the target bacteria such as aerobes, coliform and Escherichia coli were completely killed on the basis of CFU (colony forming unit) on Petrifilm plate ($3\;M^{TM}$) after 48 hr incubation. Moreover, no regrowth was found in the three groups of plankton during five days under additional exposure to the treated water. These results indicated that the disinfection efficiency of the EDS on the three groups of plankton satisfy D-2 regulation.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.799-808
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• 2021

This study was performed to investigate the extent of microbial contamination, the presence of enterotoxin genes, and the antibiotic susceptibility of Bacillus cereus in 58 red pepper plants and 43 environmental samples (soil, irrigation water, and gloves) associated with the plant cultivation. The detected counts of total aerobic bacteria, coliform bacteria, Escherichia coli, Bacillus cereus, and Staphylococcus aureus were lower in these samples, as compared to the regulations of standards for foods; moreover, pathogens, such as E. coli, E. coli O157:H7, Listeria monocytogenes, and Salmonella spp., were not detected. Genes encoding hemolysin BL enterotoxins (hblA, hblC, and hblD) as well as non-hemolytic enterotoxins (nheA, nheB, and nheC) were detected in 23 B. cereus specimens that were isolated from the test samples and had β-hemolytic activity. Interestingly, B. cereus is resistant to β-lactam and susceptible to non-β-lactam antibiotics. However, in this case, the isolated B. cereus specimens exhibited a shift from resistant to intermediate in response to cefotaxime and from susceptible to intermediate in case of rifampin, trimethoprim-sulfamethoxazole, vancomycin, clindamycin, and erythromycin. Therefore, the levels of B. cereus should be monitored to detect changes in antibiotic susceptibility and guarantee their safety.

• Journal of Environmental Health Sciences
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• v.41 no.6
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• pp.397-404
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• 2015

Objectives: The aim of this study is to investigate microbial contamination in the school food service environment for the assessment of microbial food safety. Methods: We collected both swab samples from tables and desks and airborne bacterial samples from an elementary school (School A) and a high school (School B). Heterotrophic plate count, total coliform, Staphylococcus aureus, and Bacillus cereus were measured with selective media to quantify microbial concentration. PCR assay targeting 16S rRNA genes was performed to identify the strains of S. aureus and B. cereus isolated. In addition, we made a food service checklist for the locations to evaluate the food service environment. A Wilcoxon test was employed to examine the differences in microbial concentration between before lunchtime and afterwards. Results: Heterotrophic plate counts showed higher levels after-lunch compared to before-lunch at School B. However, levels of S. aureus were higher in the after-lunch period (p<0.05) in both classrooms and in the cafeteria in School A. B. cereus was only sparsely detected in School B. Several samples from food dining carts were found to be contaminated with bacteria, and facilities associated with food delivery were found to be vulnerable to bacterial contamination. Although microbial concentrations in the air showed little difference between before- and after-lunchtime in the cafeteria in School A, those in classrooms were greater after-lunchtime at both schools. Conclusion: Our results suggested that the microbial safety in schools after lunchtime of concern. Necessary preventive measures such as hygiene education for students and food handlers should be required to minimize microbial contamination during food service processes in schools.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.117-122
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• 2017

The aim of this study was to evaluate the quality characteristics of fresh red paprika treated by electron-beam irradiation at quarantine doses. The initial microbial loads were low with $10^4$ and $10^2$ colony-forming units/g for total aerobic bacteria and coliform, respectively; however, a dose of 1 kGy resulted in load reduction of 1 log cycle. A dose level of more than 1 kGy caused significant decreases in the hardness and carotenoid content parameters. An applied dose level of less than 2 kGy did not affect vitamin C content; however, a decrease of 87-90% was observed after 40-day storage. Samples treated with 2 kGy showed significantly lower acceptance compared to the control, with lower sensory evaluation scores for color and texture. Therefore, e-beam irradiation at dose range of 0.4 and 1 kGy was found to be appropriate for quarantine applications for microbiological control and quality maintenance of paprika.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.659-663
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• 2010

This research aimed to investigate the quality of conventional salted cabbages. Here, we studied the general characteristics and microbiological aspects of purchased salted cabbage samples from 15 companies. The purchased salted cabbages used a sun-dried salt, but two samples used a mixture of sun-dried salt and processed salt. There were 4 times of washing, 3 steps of washing after automatic washing, and 3 steps of washing after bubble washing as washing methods for the salted cabbages and ground water was used as the washing water. Also, three samples received HACCP certification. The salt contained in the purchased salted cabbages ranged from 0.5% to 2.0%, representing low salted cabbages. The pH of the purchased salted cabbages ranged from 5.32 to 6.47, and hardness ranged from 1,997 g to 3,665 g. Rewashing was necessary before using some salted cabbages due to foreign materials such as insects, soil, etc. Total bacterial counts of the purchased salted cabbages ranged from 3.36 log to 6.06 log and coliform bacteria ranged from below 1 log to 6.05 log, whereas other pathogens were not detected.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.667-672
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• 2003

Low-fat, precooked high quality Wanjajun was prepared by treating natural antioxidant herbs and hydrocolloids for quantity production of cook/chill system in foodservice. The proposed Wanjajun was formulated under the consideration of flavor and fat level. Wanjajun was prepared with hydrocolloid such as sodium alginate, car-boxymethyl cellulose (CMC), carrageenan and xanthan gum. Cooking yield, fat retention and water holding capacity of Wanjajun containing hydrocolloidal gums were higher than those of control. L-value of raw product was low in comparison with cooked product, but a-value was higher than that of other cooked product. Colors of raw and cooked products were not different among five kinds of products. pH value of cooked product was higher than that of raw product pH range of cooked products revealed to 6.10~6.23. There was no considerable change in pH value during storage. The coliform group and Staphylococus aureus were not detected during storage. Total bacteria1 counts were close to microbial guidelines for safe condition. Hardness, springness, cohesiveness, gumminess and brittleness of low-fat products were generally lower than those of control product. Hardness, gumminess and brittleness of reheated products were higher than those of preheated products. Flavor, tenderness, juiciness and overall quality were not different between precooked and reheated products. Textural characteristics of products were superior in the order of sodium alginate, xanthan gum, CMC, carrageenan and control product.