• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.236-245
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• 2023

In this study, the quality safety limit period of seven types of bakery bread was analyzed, and their use-by date was calculated. For evaluating product quality, storage conditions were set as 5, 15, 25, and 35℃ for 50 days, and moisture, microorganisms, sensory characteristics, and dominant bacteria were examined. The quality and safety standards followed the Korea Food Code and Korean industrial standards (KS). The results showed that all products stored at 5℃ satisfied the standard for bacterial count for day 50, but the sensory quality was below the standard level. Samples stored at 15℃ showed high variability from 3-39 days. At 25℃, a quality safety limit period of 2-20 days was set, and one sample was found to have the same shelf life. Bread stored at 35 ℃ had the shortest quality safety limit period. Considering a safety factor of 0.87, a use-by date period of 1.7-13.1 days was calculated. Therefore, setting the use-by date according to the product type is necessary, even for the same product category. Among the bread products sold in bakeries, those managed as room temperature products (1-35℃) can be distributed and stored in a temperature range of up to 35℃. Overall, this study demonstrates the importance of setting a quality retention period based on the product characteristics and carefully considering the safety factor.

• Analytical Science and Technology
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• v.35 no.6
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• pp.267-273
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• 2022

In this study, a quality evaluation was conducted to change the sell-by date of fish cakes to the use-by date. For product quality evaluation, storage conditions were set at 5, 10, and 15 ℃, and five tests of pH, acid value, volatile basic nitrogen, bacterial count, and coliform group were performed. As a result of the experiment, the quality safety limit period of fish cakes stored at 5 ℃ was 43 days, that of fish cakes stored at 10 ℃ were 30 days, and that of fish cakes stored at 15 ℃ was 7 days. Among the five test items used for quality evaluation, the quality-limit indicators were acid value, number of bacteria, and coliform groups. The index that determined the quality safety-limit period under the three storage conditions was the bacterial count. The sell-by date of the fish cake used in this experiment was 10 days. However, through quality evaluation, the use-by date at 10 ℃ was 28.5 days, which was calculated by multiplying the 30 days; the quality limit period, by a safety factor of 0.95. However, this study conducted a quality study on one item of fish cakes from a single company, and it was difficult to use the quality safety-limit period and use-by date set in this study universally. To change the sell-by date to the use-by date, extensive quality research on various products will be required. If this system is well established, it can help reduce food waste through proper consumption of food, and consumers will be able to consume food with confidence.

• Korean journal of food and cookery science
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• v.23 no.4 s.100
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• pp.567-578
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• 2007

This study was designed to provide basic data for the application and practical use of vinegar disinfection for raw vegetable preparation in foodservice operations. The test materials were washed and disinfected by three different methods(tap water washing, chlorine water disinfection, vinegar disinfection) and stored at $3^{\circ}C$ and $10^{\circ}C$ for 7 days. Then, their microbiological qualities were compared. Total plate counts increased over the course of the storage period, and all samples, except in the case of tap water washing, remained under the permitted limit until the 7th day of storage. In particular, vinegar disinfection showed the lowest increase in total plate counts(2.35${\sim}$4.03 log CFU/g). While the total plate counts of chlorine and vinegar disinfection were within the 6.00 limit of microbiological safety, the tap water washing treatment passed the permitted limit. The psychrotrophic counts increased steadily over the course of the storage period, and increased least at $3^{\circ}C$, however, the tap water washing showed the most drastic increase, while vinegar disinfection yielded the smallest increase.

• Safety and Health at Work
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• v.6 no.2
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• pp.104-113
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• 2015

Background: Given the long hours on the road involving multiple and interacting work stressors (i.e., delivery pressures, irregular shifts, ergonomic hazards), commercial drivers face a plethora of health and safety risks. Researchers goal was to determine whether and to what extent long-haul trucker work schedules influence sleep duration and quality. Methods: Survey and biometric data collected from male long-haul truck drivers at a major truckstop in central North Carolina over a six month period. Results: Daily hours worked (mean = 11 hours, 55 minutes) and frequency of working over government-mandated daily HOS regulations (23.8% "frequently or always") were statistically significant predictors of sleep duration. Miles driven per week (mean = 2,812.61), irregular daily hours worked (63.8%), and frequency of working over the daily hour limit (23.8% "frequently or always") were statistically significant predictors of sleep quality. Conclusion: Implications of findings suggest a comprehensive review of the regulations and operational conditions for commercial motor vehicle drivers be undertaken.

• Korean Journal of Environmental Agriculture
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• v.31 no.3
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• pp.271-276
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• 2012

BACKGROUND: It is hard to control the agricultural products exceeding MRL (maximum residue limit) before forwarding. Therefore, NAQS (National Agricultural Products Quality Management Service, South Korea) established PHRL (pre-harvest residue limit) on agricultural products during their cultivation periods. This study was performed to set the PHRLs of peach during cultivation period, and also to estimate biological half-lives for residues of clothianidin and fluquinconazole. METHODS AND RESULTS: Two groups of peach were treated under Korean GAP (Good Agricultural Practices) with application time, single and triple treatments. Sample was collected over 14days (each after 0, 2, 4, 6, 8, 10, 12, 14 days. 8times), and clothianidin and fluquinconazole were analyzed by HPLC/DAD and GC/ECD, respectively. CONCLUSION: The biological half-life of clothianidin in single treatment and triple treatment was 5.2days and 7.0days. That of fluquinconazole was also 3.9days and 4.1days, respectively. The PHRL of peach on 10days before harvest was 1.4 mg/kg in clothianidin and 1.8 mg/kg in fluquinconazole.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.159-165
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• 2014

In this study, Krill Eupausia superba oil was extracted using different solvents and supercritical carbon dioxide (SC-$CO_2$). During SC-$CO_2$ extraction, the pressure was set at 40 MPa and temperatures ranged from $40^{\circ}C$ to $55^{\circ}C$. We examined the differences in volatile compounds and safety profiles among extraction methods. Volatile compounds were determined using the thermal desorption system integrated with gas chromatography-mass spectrometry (GC-MS). Heavy metal content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). According to our results 10 volatile compounds were identified in krill sample. After SC-$CO_2$ extraction of oil, the concentrations of volatile compounds decreased, but increased after solvent extraction. In krill, heavy metal concentrations remained within the permissible limit. Moreover, Zn and Fe which have health benefits were detected at high concentrations. During a 90 days storage period at different temperatures, microbial activity was found to be lowest in SC-$CO_2$ extracted residues. Thus, the quality of krill oil and the residues obtained using SC-$CO_2$ extraction was higher and the oil was safer than those obtained using conventional solvent extraction. These results can be applied to the food industry to maintain high quality krill products.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.2
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• pp.31-44
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• 2016

This study analyzed pore water pressure, earth pressure and settlement through field monitoring on the project site in which raising embankments are being built through backside extension, and compared the behaviors of seepage analysis, slope stability analysis and stress-strain during flood water levels and rapid drawdown under steady state and transient condition. The variation of pore water pressure showed an increase during the later period in both upstream and downstream slope, with downstream slope more largely increased than upstream slope overall. The variation of earth pressure increased according to the increase of embankment heights, while the change largely showed in the upstream slope, it was slowly increased in the downstream slope. The settlements largely increased until 23 m as embankment heights increased, and showed very little settlement overall. Under a steady state and transient conditions, the seepage quantity per day and leakage quantity per 100 m of embankment against total storage were shown to be stable for piping. The hydraulic gradient at the core before and after raising embankments was greater than the limit hydraulic gradient, showing instability for piping. The safety factor of upstream and downstream slopes were shown to be very large at a steady state, while the upstream slopes greatly decreased at a transit conditions, downstream slopes did not show any significant changes. The horizontal settlements, the maximum shear strain and stress are especially distributed at the connecting portion of the existing reservoir and the new extension of backside. Accordingly, the backside extension method should be designed and reinforced differently from the cases of other types reservoirs.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.316-324
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• 2022

Ethyl formate (EF) is a potent fumigant replacing methyl bromide. The use of EF is limited to a quarantine process. Appling EF to agricultural field as a safe insecticide in greenhouse give us valuable benefits including less residual concern. In this regard, residual pattern after EF fumigation in greenhouse should be undertaken. In the previous study, we have established agricultural control concentration of EF to control pests in a greenhouse. EF was fumigated at 5 g m^-3 level for 2 h. The concentration of EF inside a greenhouse was analyzed to be 4.1-4.3 g m^-3 at 30 min after fumigation. To prepare an analytical method for residues in cucumber crops and soil in the greenhouse, the limit of detection(LOD) of the method was 100ng g^-1 and the limit of quantitation(LOQ) of this method was 300 ng g^-1. R² values of calibration curves for crops and soil were 0.991-0.997. In samples collected immediately after ventilation, EF concentration was determined to be below LOQ level. In addition, EF level was below LOQ in samples collected at 3 h after ventilation except that leaf samples of melon during the flowering period showed a level of 1,068.9 ng g^-1. Taken together, these results indicate that EF used in quarantine can be applied to agricultural fields without residual issue as an effective fumigant for insect pest control.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.323-331
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• 2007

This study was designed to estimate self-life of Kimbab and sandwiches marketed in convenience store. While the 12 different type of Kimbab (n=6) and sandwiches (n=6) were kept at $10^{\circ}C$ for 72 hours, quality changes including volatile basic nitrogen, aerobic plate count, pathogens detection and sensorial property was monitored, and effective quality indicators were selected. Volatile basic nitrogen, indicator for protein deterioration was slightly increased during storage periods in all samples. E. coli, Staphylococcus aureus, Salmonella spp. and Vibrio parahaemolyticus were not detected from any of samples. Change of aerobic plate count of Kimbab and sandwiches were increased moderately but increased dramatically after 48 hours of storage. Overall acceptability were maintained over 5, purchasing power limit, for 40 hours in 4 general Kimbab, 48 hours in 2 samgak Kimbab and 42 hours in 2 sandwiches. Shelf-life of each item was calculated from regression equation between reference limit from effective quality indicators, aerobic plate count and sensory property, and storage period. Estimated shelf-lives of general Kimbab were $15{\sim}33$ hours, samgak Kimbab were 32 hours and sandwiches were $27{\sim}30$ hours at $10^{\circ}C$ refrigerated condition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.204-208
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• 2009

The withdrawal time of erythromycin in cultured olive flounder was investigated to ensure the food safety of the fish treated with erythromycin. The oral administration of erythromycin was carried out using the experimental diet containing erythromycin (200 mg/kg) daily dose of 40 mg/kg body weight. The 45 day experimental period was broken into 7 days of habituation, 8 days of medication and 30 days of additional feeding without antibiotics. The erythromycin concentration in the flounder muscle had been increased gradually with medication. After 5 days of medication, the concentration increased to its maximum level of 6.05 mg/kg. After discontinuing the antibiotic, the erythromycin concentration decreased drastically and day 9 was below 0.1 mg/kg. The erythromycin concentration had slowly declined from the 6th to the 20th day after medication and disappeared completely after 25 days. From these results, the time needed to reduce the erythromycin level to the 0.2 mg/kg limit adopted by the ED and Japan was suspected to be 4-6 days. Therefore, a reasonable withdrawal time following ED and Japanese regulatory guidelines for erythromycin in the cultured flounder could be estimated to be 10 days.