• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.13-21
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• 2019

A method was developed for the simultaneous detection of an antibiotic fungicide, streptomycin, and its metabolite (dihydrostreptomycin) in agricultural products using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted using methanol adjusted to pH 3 using formic acid, and purified with a HLB (Hydrophilic lipophilic balance) cartridge. The matrix-matched calibration curves were constructed using seven concentration levels, from 0.001 to 0.1 mg/kg, and linearity of five agricultural products (hulled rice, potato, soybean, mandarin, green pepper), with coefficients of determination $(R^2){\geq}0.9906$, for streptomycin and dihydrostreptomycin. The mean recoveries at three fortification levels (LOQ, $LOQ{\times}10$, $LOQ{\times}50$, n = 5) were from 72.0~116.5% and from 72.1~116.0%, and relative standard deviations were less than 12.3% and 12.5%, respectively. The limits of quantification (LOQ) were 0.01 mg/kg, which are satisfactory for quantification levels corresponding with the Positive List System. All optimized results satisfied the criteria ranges requested in the Codex guidelines and the Food Safety Evaluation Department guidelines. The present study could serve as a reference for the establishment of maximum residue limits and be used as basic data for detection of streptomycin and dihydrostreptomycin in food.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.15-21
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• 2013

The detection characteristics of irradiated spices were investigated depending on radiation sources and doses by photostimulated luminescence (PSL) and Thermoluminescence (TL). 6 kinds of spices (turmeric, onion powder, red pepper, basil, parsley, black pepper) were irradiated at 0 to 10 kGy under ambient conditions by both a $^{60}Co$ gamma irradiator and an electron beam (EB) accelerator, respectively. The PSL analysis showed negative results for non-irradiated spices, while irradiated spices gave intermediate and positive value, which presented the limited potential of PSL technique. In TL measurement, TL glow curves on non-irradiated samples appeared at about $300^{\circ}C$ with low intensity. All irradiated samples were easily distinguishable through radiation-specific strong TL glow curves with maximum peak in range of $150{\sim}200^{\circ}C$. TL ratio ($TL_1/TL_2$) obtained by a re-irradiation step could verify the detection result of $TL_1$ glow curves, showing ratios lower than 0.1 in the non-irradiated sample and higher than 0.1 in irradiated ones. Therefore, in PSL measurement, the identification of irradiated spices showed more clear results in electron beam irradiated samples. TL analysis showed obvious difference between non-irradiated and irradiated samples in gamma ray and electron beam irradiated samples.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.30-39
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• 2019

An analytical method was developed for the determination of sedaxane in agricultural products using liquid chromatograph-tandem mass spectrometry (LC-MS/MS). The samples were extracted with acetonitrile and partitioned with dichloromethane to remove the interference, and then purified by using silica SPE cartridges to clean up. The analytes were quantified and confirmed by using LC-MS/MS in positive ion mode using multiple reaction monitoring (MRM). The matrix-matched calibration curves were linear over the calibration ranges ($0.001-0.25{\mu}g/mL$) into a blank extract with $r^2$>0.99. For validation, recovery tests were carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ, n=5) with five replicates performed at each level. The recoveries were ranged between 74.5 to 100.8% with relative standard deviations (RSDs) of less than 12.1% for all analytes. All values were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL 40, 2003) and Food Safety Evaluation Department guidelines (2016). The proposed analytical method was accurate, effective and sensitive for sedaxane determination in agricultural commodities.

• Analytical Science and Technology
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• v.22 no.4
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• pp.345-353
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• 2009

The new anti-impotency analogue was identified in food source. Detection of this analogue was accomplished through screening of food samples by liquid chromatography/photodiode array detector. The spectrum pattern of analogue compound was similar to that observed for hongdenafil which was analogue of sildenafil. This new compound was isolated and purified using the liquid-liquid extraction, thin layer chromatography, column chromatography and preparative HPLC. And then those structure were identified using analytical instruments such as HPLC/PDA, LC/MS/MS and NMR. The compound was given a name to oxohongdenafil which was replaced with acetyl oxoethylpiperazinyl residue instead of sulfonyl piperazine group of sildenafil. The regulation for the abovementioned analogue, oxohongdenafil, was established by Standard of Korean food code.

• Journal of Community Nutrition
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• v.7 no.3
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• pp.141-148
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• 2005

Food handling practices playa key role in the prevalence of food-borne illness. Despite the fact that pregnant women are high risk groups for food-borne disease, little is known about their actual food handling practices at home. The objective of this study was to investigate behaviors regarding food-related hygienic practices of pregnant women. The questionnaire included questions in five major areas : personal hygiene ; adequate cooking ; avoiding cross contamination ; keeping food at safe temperatures ; and avoiding food from unsafe sources. Analysis of 488 questionnaires showed the respondents were unaware of the importance of safe food handling practices. Especially, pregnant women in our study should be encouraged to be careful about either risk of adequate cooking $(2.08\pm0.66)$ and keeping foods at safe temperatures $(2.69\pm0.63)$. Residency and number of children were consistent independent predictors of food handling behaviors. Previous food safety education also was found to have significant effect on food handling practices. TV news and newspapers were considered the most usable sources of food safety information by respondents. The behaviors identified in this study represent ones of particular importance for high-risk populations, like pregnant women. These population characteristics identified in this study could be incorporated in development of food safety educational programs for pregnant women being vulnerable on food-borne illness. Our results could have implications for the design of effective food safety educational efforts. This study indicates the need for continued and improved food safety education and for enforcing systematic food safety education for pregnant women.

• Analytical Science and Technology
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• v.29 no.6
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• pp.255-260
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• 2016

Based on the Korean Health Functional Food Act, health functional foods are dietary supplements containing nutrients or other substances that have nutritional or physiological effects. Since generic health functional food items have been expanded, this project was performed to develop a standardized analytical method of examining such sale items. The method exhibited high linearity in the quercetin calibration curve ($R^2$ > 0.999) over concentrations of $0-40{\mu}g/mL$. The limits of detection and quantitation for quercetin were $0.12{\mu}g/mL$ and $0.36{\mu}g/mL$, respectively, while quercetin recovery was 97.1-105.4 % with standard deviations of 1.15-3.11 %. To verify the accuracy of the analytical methods, the labeled amounts of purchased health functional foods were monitored. The recovery rate for multiple quercetin concentrations ranged from 82.5-105.1 % of the labeled amounts. Thus, the new method was suitable for all cases.

• Food Science and Industry
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• v.43 no.3
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• pp.55-68
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• 2010

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.148-155
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• 2013

Sulfoxaflor is a new active ingredient within the sulfoximine insecticide class that acts via a unique interaction with the nicotinic receptor. The MRLs (maximun residue limit) of sulfoxaflor in apple and pear are set at 0.4 mg/kg and that in pepper is set at 0.5 mg/kg. The purpose of this study was to develop an analytical method for the determination of sulfoxaflor residues in agricultural commodities using HPLC-UVD and LC-MS. The analysis of sulfoxaflor was performed by reverse phase-HPLC using an UV detector. Acetone and methanol were used for the extraction and aminopropyl ($NH_2$) cartridge was used for the clean-up in the samples. Recovery experiments were conducted on 7 representative agricultural products to validate the analytical method. The recoveries of the proposed method ranged from 82.8% to 108.2% and relative standard deviations were less than 10%. Finally, LC-MS with selected ion monitoring was also applied to confirm the suspected residues of sulfoxaflor in agricultural commodities.

• Journal of the Korean Dietetic Association
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• v.13 no.2
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• pp.169-182
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• 2007

We investigated elementary school students' knowledge, behavior, experience and preference of education method related to food safety in order to provide basic information for food safety educational program. A survey study was conducted with 569, fourth and sixth grade students, from two schools in Seoul and Ulsan. Students were asked thirty-two questions regarding food safety knowledge, behavior and experiences as well as their attitude to food safety class and preference for teaching method. The data was analyzed for the frequency analysis, t-test, chi-square test, one-way ANOVA and Pearson correlation using the SPSS/Windows. Results indicated that 91.9 percent of the respondents did not know what unsanitary food is. 67 percent of the respondents did not know the proper method of hand washing. Although the students' level of knowledge and behavior associated with food safety was low, there was meaningful correlation(r =.184, p<.01) between knowledge and behavior. Surprisingly, students in higher grade did not demonstrate an exceeding food safety knowledge and behavior. More than 50 percent of the subjects did not have food safety education either at home or school. 60 percent of the respondents interested in food safety and the majority recognized that a food safety education is needed. Students want to learn about unsanitary food(34.1%), foodborne illness(29.7%), food selection and storage method(21.3%), and personal hygiene(11.2%) through game, role play, and practice in real situation. These results suggest that development of food safety education program is needed through the elementary school year and the education program must include fun activities in which students can participate.

• Safe Food
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• v.2 no.4
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• pp.17-22
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• 2007