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He W.,Xuchang University | He W.,U.S. Food and Drug Administration | Jia H.,Xuchang University | Yang D.,Xuchang University | And 6 more authors.
ACS Applied Materials and Interfaces | Year: 2015

The ability of nanostructures to facilitate the generation of reactive oxygen species and charge carriers underlies many of their chemical and biological activities. Elucidating which factors are essential and how these influence the production of various active intermediates is fundamental to understanding potential applications of these nanostructures, as well as potential risks. Using electron spin resonance spectroscopy coupled with spin trapping and spin labeling techniques, we assessed 3 mixed metal sulfides of varying compositions for their abilities to generate reactive oxygen species, photogenerate electrons, and consume oxygen during photoirradiation. We found these irradiated mixed metal sulfides exhibited composition dependent generation of ROS: ZnIn2S4 can generate •OH, O2-• and 1O2; CdIn2S4 can produce O2-• and 1O2, while AgInS2 only produces O2-•. Our characterizations of the reactivity of the photogenerated electrons and consumption of dissolved oxygen, performed using spin labeling, showed the same trend in activity: ZnIn2S4 > CdIn2S4 > AgInS2. These intrinsic abilities to generate ROS and the reactivity of charge carriers correlated closely with the photocatalytic degradation and photoassisted antibacterial activities of these nanomaterials. (Figure Presented) © 2015 American Chemical Society.


Lee W.,Hokkaido University | Koh S.-H.,Korea forest Research Institute | Choi W.I.,Korea forest Research Institute | Jung C.S.,Korea forest Research Institute | And 8 more authors.
Journal of Asia-Pacific Entomology | Year: 2012

A total of 103 barcode (mitochondrial COI) sequences were newly provided for 77 forest insect pests from 66 genera belonging to Coleoptera, Hemiptera, and Lepidoptera. All 77 species had distinct COI sequences, revealing low intraspecific genetic divergence (< 1.20%) and high interspecific genetic divergence (> 7.30%). Among the 66 genera, 32 COI sequences of 25 species belonging to 16 genera were compared with 280 COI sequences of 117 species belonging to the same 16 genera archived in GenBank, showing that most species were clearly distinguished by barcode sequences. Based on these results, we conclude that a DNA barcode is effective for identifying forest insect pest species. © 2012.


Hong S.I.,Korea University | Kim J.Y.,Food Safety Bureau | Cho S.Y.,Korea University | Park H.J.,Korea University
Food Chemistry | Year: 2010

The objective of this study was to investigate the effects of gamma irradiation on changes in oleic acid of methyl oleate as well as of beef and olive oil. The samples were irradiated at doses ranging from 0 to 60 kGy and the fatty acid composition was then analyzed by GC-FID and GC-MS. Gamma irradiation upon methyl oleate induced the formation of trans octadecenoic acid and stearic acid in a dose dependent fashion, while it decreased the amount of oleic acid. These findings indicate that the 9-cis structure is responsible for the formation of trans and saturated configurations. Additionally, the formation of stearic acid was facilitated by high temperature during the irradiation. Conversely, irradiation dose and temperature during irradiation had no significant effect (p > 0.05) on the amount of trans or saturated fatty acids in the beef and olive oil. © 2009 Elsevier Ltd. All rights reserved.


Kim M.O.,Center for Food and Drug Analysis | Hwang H.S.,Center for Food and Drug Analysis | Lim M.S.,Center for Food and Drug Analysis | Hong J.E.,Center for Food and Drug Analysis | And 4 more authors.
Korean Journal of Food Science and Technology | Year: 2010

This survey was carried out to estimate pesticide residue levels in commercial agricultural products in the year 2009. Residues were examined in 16 commodities (rice, foxtail millet, buckwheat, kidney beans, peanuts, sesame, oranges, grapefruit, kiwifruit, spinach, perilla leaves, leeks, garlic stem, garlic, ginger, and oak mushroom) collected from 22 provinces in Korea. Analyses were performed by multi-methods capable of detecting up to 60 pesticides by LC/MS/MS. A total of 510 samples were collected and analyzed. Of the samples, 96.1% contained no detectable pesticide residues. Detectable residues at or below the MRLs were found in 3.5% of the samples. However, in 0.4% of the samples (spinach and leeks), residue (ethaboxam and fluquinconazole) levels exceeded the MRLs. Furthermore, intake assessments of 7 kinds of pesticide residues were carried out, excluding those exceeding the MRLs. The results showed that the ratios of EDI (estimated daily intake) to ADI (acceptable daily intake) were 0.0001-0.0006%, which indicates that the detected pesticide residues were in a safe range. It is concluded that residual pesticides in agricultural products are properly controlled in Korea. © The Korean Society of Food Science and Technology.


Choi M.-H.,Duksung Womens University | Youn S.-J.,Duksung Womens University | Ahn Y.-S.,Food Safety Bureau | Seo K.-J.,Risk Prevention Policy Bureau | And 2 more authors.
Journal of the Korean Society of Food Science and Nutrition | Year: 2010

This study investigated consumer's recognition of food labeling in order to contribute to the development of food labels which are more informative to consumers. The questionnaires had been collected from 120 male and female customers living in Seoul with the age between 10's and 60's from November 2nd to November 7th 2009. For checking the food label at the time of purchase, 58.3% of the consumers checked the food label and the main reason for checking the food label was to confirm sell-by date (60.1%). Sixty percent of the consumers were satisfied with the current food labeling. Among those who are not satisfied, 30.6% complained about difficult terms to understand and 25.8% were dissatisfied with insufficient information. In every age group, most people were not satisfied with labeling on food ingredient and additives, followed by date of manufacture and sell-by date. 53.1% of consumers demanded to label date of manufacture and sell-by date together. For more clear information, consumers wanted use-by date (47.5%) rather than sell-by date (23.3%). 56.7% of consumers was dissatisfied with warning information such as allergic warning and the reasons for dissatisfaction were poor visibility (37.5%) and insufficient information (33.4%). Moreover most consumers (90.0%) showed little knowledge on irradiation. To improve of the food labeling standards into consumer-oriented standards, both amendment of the food labeling standards and consumer education will be necessary.


Im M.-H.,Food Safety Bureau
Journal of the Korean Society for Applied Biological Chemistry | Year: 2013

All countries worldwide are experiencing difficulties in setting maximum residue limits (MRLs) for pesticide residues in food commodities due to prohibitive costs, labor, and other expenses. The Codex Alimentarius (Codex) is actively engaged in revising the classification of food commodities that are grown in small areas; however, setting MRLs for all agricultural commodities has not been effective. Modified food classifications for groups of agricultural commodities were established for setting MRLs of pesticides for each food commodity. Codex accepted various countries' opinions that the old food classification of commodities can no longer be applied to the present food classifications; therefore, from 2009, Codex started to revise their food classifications. To set pesticide MRLs for agricultural products grown in small fields, groups of agricultural commodities were subdivided, and new food classifications were used. The food classification revised by Codex made it easy to set up group MRLs. After the Codex food classification was revised, jujube and persimmon, which were previously classified as tropical fruits, were grouped as pome fruits and stone fruits based on the opinion of the Korea Food & Drug Administration (KFDA). In addition, KFDA submitted more comments on the classification of various vegetables. As a result, Korean vegetables were included in the food classification by Codex. The current Codex food classifications in Korea still have not adopted a group-specific subdivision system that is already used in Codex and the US internationally harmonized food classification revisions by Codex might resolve the difficulty of setting up pesticide MRLs for agricultural commodities such as vegetables in Korea. Consequently, food classifications in Korea, which are in harmony with the Codex food classification, will be of great help in setting the group MRLs for the minor crops of Korea. © 2013 The Korean Society for Applied Biological Chemistry.

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