ABSTRACT
The aim of this study was to determine the non-intentionally added substances--formaldehyde and trace metals--at 4% acetic acid conditions in rubber and metallic packaging/utensils. The temperature effect on migration in rubber and metallic packaging/utensils was monitored at 60 °C and 100 °C under acidic (pH < 3) circumstances. The concentrations were: formaldehyde--23.1 µg kg⻹, lead--13.41 µg kg⻹, cadmium--0.15 µg kg⻹, total arsenic--2.02 µg kg⻹ and nickel--2.92 µg kg⻹ at 60 °C and formaldehyde--148.9 µg kg⻹, lead--17.04 µg kg⻹, cadmium--0.14 µg kg⻹, total arsenic--7.25 µg kg⻹ and nickel--8.7 µg kg⻹ at 100 °C. A significant difference was noticed in formaldehyde and total arsenic between both temperatures (p < 0.01), which was not present in other trace metals. In conclusion, formaldehyde and total arsenic were more sensitive with cooking temperature than the other metals.
Subject(s)
Cooking and Eating Utensils , Food Contamination/prevention & control , Food Packaging , Formaldehyde/analysis , Metals, Heavy/analysis , Metals/chemistry , Rubber/chemistry , Arsenic/analysis , Arsenic/chemistry , Arsenic/toxicity , Cadmium/analysis , Cadmium/chemistry , Cadmium/toxicity , Cooking and Eating Utensils/economics , Cooking and Eating Utensils/standards , Food Packaging/economics , Food Packaging/standards , Formaldehyde/chemistry , Formaldehyde/toxicity , Guidelines as Topic , Hot Temperature/adverse effects , Humans , Hydrogen-Ion Concentration , Lead/analysis , Lead/chemistry , Lead/toxicity , Limit of Detection , Materials Testing , Metals, Heavy/chemistry , Metals, Heavy/toxicity , Nickel/analysis , Nickel/chemistry , Nickel/toxicity , Reproducibility of Results , Republic of Korea , SolubilityABSTRACT
In this study, the quick HPLC-MS/MS method for the simultaneous separation of 2-acetyl-4(5)-tetrahydrox-ybuthylimidazole (THI) and 4-(5)-methylimidazole (4-MI) in alkaline medium was used for caramel color and processed foods in Korea. After a simple sample pretreatment, 51 4-MI-labeled samples were positive for 4-MI and 2 also contained THI. The concentration of 4-MI was 260.5 ~ 24,499.3 µg/kg in caramel color, less than LOD ~ 1,712.5 µg/kg in sauce, 1,242.3, 5,972.2 µg/kg in balsamic vinegar, 2,118.3 ~ 5,802.4 µg/kg in complex seasoning, 82.7 ~ 5,110.6 µg/kg in curry, and 29.9 ~ 464.4 µg/kg in soft drinks. The recovery rate of 4-MI was 97.1 ~ 111.0% in sauce and 81.9 ~ 110.0% in powder and that of THI was 83.6 ~ 106.4% in sauce and 61.2 ~ 99.4% in powder. Our results concluded a safe amount of 4-MI and THI compared to the limit of Korea additive code but the processed foods do not have a limit of caramel color and 4-MI in Korea. Therefore, research and monitoring of 4-MI and THI is needed for processed foods in Korea.
ABSTRACT
The purpose of this study was to investigate the antimicrobial resistance and to characterize the implicated genes in Escherichia coli isolated from commercial fish and seafood. Fish and seafood samples (n=2663) were collected from wholesale and retail markets in Seoul, Korea between 2005 and 2008. A total of 179 E. coli isolates (6.7%) from those samples were tested for resistance to a range of antimicrobial agents. High rates of resistance to the following drugs were observed: tetracycline (30.7%), streptomycin (12.8%), cephalothin (11.7%), ampicillin (6.7%) and ticarcillin (6.1%). No resistances to amikacin, amoxicillin/clavulanic acid and cefoxitin were observed. Seventy out of 179 isolates which were resistant to one or more drugs were investigated by PCR for the presence of 3 classes of antimicrobial resistance genes (tetracycline, aminoglycosides and beta-lactams), class 1, 2 and 3 integrons. Gene cassettes of classes 1 and 2 integrons were further characterized by amplicon sequencing. The tetracycline resistance genes tetB and tetD were found in 29 (41.4%) isolates and 14 (20%) isolates, respectively. The beta-lactam resistance gene, bla(TEM) was found in 15 (21.4%) isolates. The aminoglycoside resistance gene, aadA was found in 18 (25.7%) isolates. Class 1 integron was detected in 41.4% (n=29) of the isolates, while only 2.9% (n=2) of the isolates were positive for the presence of class 2 integron. Two different gene cassettes arrangements were identified in class 1 integron-positive isolates: dfrA12-aadA2 (1.8 kb, five isolates) and aadB-aadA2 (1.6 kb, four isolates). One isolate containing class 2 integron presented the dfrA1-sat-aadA1 gene cassette array. These data suggest that commercial fish and seafood may act as the reservoir for multi-resistant bacteria and facilitate the dissemination of the resistance genes.
