• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.277-284
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• 2012

The objective of this study was to investigate and evaluate microbial contamination levels of leafy greens (perilla leaf and lettuce) and its distributing conditions at different seasons (Feb, May, Aug, and Nov of the year 2011) in order to provide insight into any potential health hazards associated with consumption of these commodities. Leafy greens were collected from a farm located in Geumsan, Chungnam and wholesale markets (WM) and traditional markets (TM) located in Suwon. At the same time, temperature and relative humidity fluctuations experienced by the leafy greens during distribution from the farm to the distribution center were measured by a data logger. The contamination levels of perilla leaf and lettuce were determined by analyzing total plate count. Coliform groups, Bacillus cereus, Escherichia coli, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and Staphylococcus aureus were determined. The contamination levels of total aerobic bacteria, coliform groups and B. cereus in both vegetables sampled during May and August found to be higher than those sampled during February and November. E. coli O157:H7, Salmonella spp., L. monocytogenes were not detected in the vegetables analyzed in this study. There were no significant trends between samples at WM and TM in the contamination levels. Relative humidity of vegetables distributed from the farm to the distribution center showed over 90% during distribution regardless of measured seasons. In the case of background microflora on leafy greens, the density was significantly increased at 20, 30 and $37^{\circ}C$ during storage of 24h. E. coli O157:H7 and B. cereus inoculated on the leaves also showed similar increases in the storage tests. The microbial contamination levels determined in this study may be used as the fundamental data for microbial risk assessment.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.37-44
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• 2020

This study investigated the probability of foodborne illness caused by raw oyster consumption contaminated with high risk Vibrio species such as V. vulnificus and V. cholerae. Eighty-eight raw oyster samples were collected from the south coast, west coast and Seoul areas, and examined for the prevalence of high risk Vibrio species. The growth patterns of V. vulnificus and V. cholerae in raw oysters were evaluated, and consumption frequency and amounts for raw oyster were investigated from a Korean National Health and Nutrition Examination Survey. With the collected data, a risk assessment simulation was conducted to estimate the probability of foodborne illness caused by intake of raw oysters, using @RISK. Of 88 raw oysters, there were no V. vulnificus- or V. cholerae-positive samples. Thus, initial contamination levels of Vibrio species in raw oysters were estimated by the statistical methods developed by Vose and Sanaa, and the estimated value for the both Vibrio spp. was -3.6 Log CFU/g. In raw oyster, cell counts of V. vulnificus and V. cholerae remained unchanged. The incidence of raw oyster consumers was 0.35%, and the appropriate probabilistic distribution for the consumption amounts was the exponential distribution. A risk assessment simulation model was developed with the collected data, and the probability of the foodborne illness caused by the consumption of raw oyster was 9.08×10^-15 for V. vulnificus and 8.16×10^-13 for V. cholerae. Consumption frequency was the first factor, influencing the probability of foodborne illness.

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.7-12
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• 2013

This study presents the influence on growth properties determined using a novel predictive growth model of wild-type Salmonella spp. KSC 101 by variations in the temperature and time during cut packaging in cold, uncooked pork meat. The experiment performed for model development included an arrangement of different temperatures ($0^{\circ}C$, $5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, and $20^{\circ}C$) and time durations (0, 1, 2, and 3 hours) that reflect actual pork-cut and packaging processes. No growth was observed at $0^{\circ}C$ and $5^{\circ}C$, whereas some growth was observed at $10^{\circ}C$, $15^{\circ}C$, and $20^{\circ}C$, with a mean increase of only 0.34 log CFU/g. The growth observed at $20^{\circ}C$ was more robust than that observed at $15^{\circ}C$, but the difference was not statistically significant (p > 0.05). However, compared with PMP (Pathogen Modeling Program), the wild-type Salmonella spp. KSC 101 showed a more rapid growth. We used the Gompertz 4 parameter equation as the primary model, and the exponential decay formula as the secondary model. The estimated $R^2$ values were 0.99 or higher. The developed model was evaluated by comparison of the experimental and predictive values, and the values were in agreement with the ${\pm}0.5$ log CFU/g, although the RMSE (Root mean square error) value was 0.103, which indicates a slight overestimation. Therefore, we suggest that the developed predictive growth model would be useful as a tool for evaluating sanitation criteria in pork cut-packaging processes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.78-90
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• 1993

This study was designed obtain and early detection the workers exposed to excessive copper dust and also to present biological exposure index. The exposed group consisted of 62 male workers at the metallurgy workplaces. To evaluate the degree of individual exposure the copper dust, each personal air sampling was collected. Biological exposures in the exposed group was quantified for the blood and urine copper levels using flameless atomic absorption spectrophotometer. The control group consisted of 70 male adults with the history of nonexposure to copper by the inhalation occupationally. The average concentration of copper in blood and urine of the exposed group was $49.44{\pm}8.90(29.05-80.63){\mu}g/dl$, $39.99{\pm}11.04(29.62-80.63){\mu}g/l$ respectively. The average concentration of air borne copper was $0.48{\pm}0.31(0.03-1.18)mg/m^3$. The average concentration of blood and urine copper in the control group was $42.93{\pm}5.84(25.05-57.85){\mu}g/dl$, $33.02{\pm}13.38(12.00-82.05){\mu}g/l$ respectively. The difference observed in the average concentration of blood and urine copper of the exposed and control groups was statistically significant seperately (blood copper, p<0.05 ; urine copper, p<0.05). The relationship between the individual exposure concentration of air borne copper and the concentration of the blood and urine copper was statistically significant, respectively (blood copper, r=0.54, p<0.05 ; urine copper, r=0.37, p<0.05). The relationship between the working duration and the concentration of blood and urine was not statistically significant respectively (blood copper, r=0.14 ; urine copper, r=0.12). The relationship between the age and the concentration of blood and urine copper was statistically not significant respectively (blood copper, r=013 ; urine copper, r=-0.06). The relationship between blood and urine copper concentration in the exposed group was statistically significant (r=0.62, p<0.05), and the relationship between blood and urine copper concentration in the control group was also statistically significant (r=0.39, p<0.05).

• Journal of Nutrition and Health
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• v.47 no.4
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• pp.300-312
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• 2014

Purpose: This study was performed to examine the sanitary knowledge level and degree of HACCP (hazard analysis critical control point) practice in school culinary staff in order to provide basic information for improving hygiene of school meals. Methods: Exactly 305 culinary staff members were selected from elementary, middle, and high schools in 14 cities and rural areas, including whole administrative districts in Chungnam province. Surveyed schools were selected by convenience sampling, and one subject was selected randomly from each school. Surveys were taken by self-administered questionnaires developed by researchers and questionnaire were distributed and collected by postal mail. Results: Sanitary education administered by school dietitians to culinary staff was more frequent and longer in elementary schools, followed by middle and high schools (p < 0.001). Sanitary knowledge level and degree of HACCP practice, except for a few CCP or CP of culinary staff, were highest in elementary schools and middle school followed by high schools (p < 0.05), respectively. School class was negatively correlated with sanitary knowledge level of culinary staff (p < 0.01), and frequency of sanitary education was positively correlated with sanitary knowledge level of culinary staff (p < 0.01). Sanitary knowledge level of culinary staff was positively correlated with degree of HACCP practice (p < 0.01). School class, daily frequency of meal service, work experience, rice washing machine, and total score of sanitary knowledge were significant variables influencing degree of HACCP practice in culinary staff. Conclusion: The above results show that the following points should be considered to improve hygiene of school meals. Sanitary education should be administered more frequently by school dietitians to culinary staff, especially to those in high schools, which showed the lowest sanitary knowledge level and degree of HACCP practice. In addition, facilities and equipment required for HACCP practice should be supported in small-sized elementary schools.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.432-441
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• 2012

In this study, the transfer rate of wild type Listeria mon, ytogenes (LM) was investigated to establish the standard of safety management during pork meat pr, essing for meat to meat and meat to food contact surfaces contamination at 5 and $10^{\circ}C$. The transfer rate of LM from meat to meat during the pr, essing increased from 0.02% after 30 min to 0.42% after 120 min at $5^{\circ}C$, while for conveyor belt and stainless steel, it decreased from 0.015% and 0.013% after 30 min to 0.002% and 0.0003% after 120 min at $5^{\circ}C$, respectively (p < 0.05). When temperature increased to $10^{\circ}C$, the transfer rates of LM from meat to meat, conveyor belt and stainless steel were the highest at 60 min exposure, and all decreased after 120 min. In reverse, the transfer rate from food contact surface to pork meat was significantly higher than that from pork meat to food contact surface (p < 0.01). Also, the transfer rate to conveyor belt was significantly higher than stainless steel (p < 0.05) and it was highest at 30 min exposure time in both 5 and $10^{\circ}C$. This study indicates that the transfer and adherence rates of LM are influenced by the contact time and temperature. Consequently, these results were utilized to develop a predictive model with a high level of confidence which can lead to prevent cross-contamination during pork meat processing.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.336-344
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• 2010

Considering the increasing trends of the consumption of livestock products in Korea, proper hygienic management and policies for ensuring their safety to protect public health and strengthen consumer confidence are demanded. It is particularly important to manage the livestock distribution processes to provide safe meat and meat products. This study was conducted to examine factors related to the hygiene management of livestock products and to check out the condition of hygienic management in meat markets. To accomplish this, 156 meat markets divided into HACCP-certified and non certified and evaluated for five factors, which received the following scores: facility and equipment management (1.00/2.0 points, 50.0%), storage and transport management (1.93/2.0 points, 96.5%), work place management (0.76/2.0 points, 38.0%), personal hygiene management (0.75/2.0 points, 37.5%), and inspection management (0.22/2.0 points, 11.0%). The results revealed that the scores of HACCP-certified meat markets were significantly higher than those of the non certified markets (p<0.05, p<0.01, p<0.001). These findings suggest that meat markets that are not HACCP-certified must improve hygienic management conditions and educate their employees to improve the safety of livestock products during distribution.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.123-130
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• 2023

Salmonella spp. are prevalent foodborne pathogens that are infective at relatively low concentrations, thus posing a serious health threat, especially to young children and the elderly. In several countries, the management and regulation of Salmonella spp. in food, including seafood, adhere to a negative detection standard. The risk of infection is particularly high when seafood is consumed raw, which underscores the importance of timely detection of pathogenic microorganisms, such as Salmonella. Accordingly, this study aimed to develop a combined pre-treatment and detection method that includes pre-culture and DNA extraction in order to detect five species of Salmonella at concentrations below 10 CFU/mL in seafood. The effectiveness of the proposed method was assessed in terms of the composition of the enrichment (pre-culture) medium, minimum incubation time, and minimum cell concentration for pathogen detection. Furthermore, a practical DNA extraction method capable of effectively handling high salt conditions was tested and found to be successful. Through polymerase chain reaction, Salmonella spp. Were detected and positively identified in shellfish samples at cell concentrations below 10 CFU/g. Thus, the proposed method, combining sample pre-treatment and cell culture with DNA extraction, was shown to be an effective strategy for detecting low cellular concentrations of harmful bacteria. The proposed methodology is suitable as an economical and practical in situ pre-treatment for effective detection of Salmonella spp. in seafood.

• The Journal of Korean society of community based occupational therapy
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• v.10 no.1
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• pp.31-38
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• 2020

Objective : The purpose of this study is to investigate the effects of bilateral chewing exercise applied for 6 weeks on occlusion force and masseter muscle thickness in the elderly living in the community. Methods : This study recruited 25 community residents. All participants performed bilateral chewing exercise using equipment developed for the purpose of oral chewing exercise. The chewing exercise was divided into isometric and isotonic type and applied for about 20 minutes a day, five times a week for six weeks. For the evaluation, the masseter muscle thickness and the maximum occlusion force were measured three times at three week intervals using a portable ultrasound instrument and an occlusion force gauge. Results : As a result of the change in masseter muscle thickness, baseline, 3 weeks later, and 6 weeks later referred to 7.51±0.43, 7.63±0.44, and 7.83±0.46, respectively (F=3.819, p<.05). The post hoc test resulted in a significance between baseline and 6 weeks later (p=0.023). Similarly, as a result of the change in occlusion force, baseline, 3 weeks later, and 6 weeks later referred to 265±9.22, 268±9.57, and 271.59±10.16, respectively (F=3.031, p<.05). The post hoc test resulted in a significance between baseline and 6 weeks later (p=0.048). Conclusion : This study confirmed that bilateral chewing exercise was effective for increasing masseter muscle thickness and occlusion force in the elderly. Therefore, bilateral chewing exercise can be applied as a therapeutic exercise method for improving oral function.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.324-331
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• 2009

Peeled whole onions (PWO) were cleaned at various hypochlorous acid (HA) concentration and steeping time and packed in LDPE bag keeping at $10^{\circ}C$ for 12 days and $35^{\circ}C$ for 3 days, in order eventually to examine microbiology, surface color and sensory quality. At the early stage of storage, it was found that total bacterial counts at H-II keeping at $10^{\circ}C$ after 1 minute steeping were $2.60\;{\pm}\;0.18\;log\;CFU/g$, and those after 3 minutes steeping were $2.10\;{\pm}\;0.18\;log\;CFU/g$ which showed less than the control. The total bacterial counts at H-III were detected after 4 days. The total bacterial counts of PWO treated HA increased as steeping time became longer, HA concentration increased, and storage temperature went down. E. coli was not detected at all treatments. It was also found that during the treatment the L-value showed decreasing trend, but the parameter a- and b- value showed increasing trend. But these trends were mitigated as HA concentration increased. The result of sensory quality evaluation for the appearance showed that the sample stored with $10^{\circ}C$ gained higher evaluation than that with $10^{\circ}C$, while the control and H-III gained highest points significantly (p < 0.05) for the sample keeping at $10^{\circ}C$ after 12 days storage. The sensory odor of onion showed similar to that for the appearance, and the 8-day treatments of H-II and H-III showed no significantly difference (p < 0.05). On the basis of the results above, it is likely to be more effective to prolong the period of circulation of PWO if you use HA over 50 ppm for washing PWO and storage at $10^{\circ}C$. This study will contribute to improve safety and quality in circulation of PWO.