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Ōsaka, Japan

Ohtsubo Y.,Japan Ecotech Co. | Kurooka H.,Japan Ecotech Co. | Tada H.,Japan Ecotech Co. | Manabe N.,University of Tokyo
Journal of the Food Hygienic Society of Japan | Year: 2014

In Japan, a criterion value of histamine residue in food is not clearly defined and there is no official test method. We examined histamine in fish and fish products according to the food sanitation test guideline (fluorescence derivatization of histamine with dansyl chloride and quantification by LC-FL: the LC-FL method). Positive samples were confirmed by determining dansylated histamine using our developed LC-MS/MS procedure (the LC-MS/MS method) when histamine was detected. Validation was earried out according to the validation test guideline using fresh fish. Recovery tests of histamine from fresh fish spiked at the level of 20 ppm were carried out. The limit of quantification was 5 ppm. The results confirmed that our LC-MS/MS method is applicable for the inspection of fish and fish products. This LC-MS/MS method has a lower false-positive ratio and a higher selectivity than the LC-FL method. Source

Sakamoto K.,Japan Ecotech Co. | Nishizawa H.,Japan Ecotech Co. | Manabe N.,University of Tokyo
Journal of the Food Hygienic Society of Japan | Year: 2012

In Japan, maximum residue limits for pesticides (MRL) in coffee are set on green coffee beans, but not roasted coffee beans, although roasted beans are actually used to prepare coffee for drinking. Little is known about the behavior of pesticides during the roasting process. In the present study, we examined the changes in the concentration of pesticide (organochlorine: γ-BHC, chlordane and heptachlor) residues in coffee beans during the roasting process. We prepared green coffee beans spiked with these pesticides (0.2 and 1.0 μg/g), and the residue levels in the beans were measured before and after the roasting process. We determined the residual rate after the roasting process. γ-BHC was not detectable at all, and more than 90% of chlordane was lost after the roasting (3.1 and 5.1% of chlordane remained in the beans spiked with 0.2 and 1.0 |ig/g of chlordane, respectively). A low level of heptachlor (0.72%) was left in the coffee beans spiked with 1 |ig/g of heptachlor. Disappearance of γ-BHC during the roasting process may be due to the high vapor pressure of γ-BHC, while chlordane has a lower vapor pressure. We also examined the behavior of piperonyl butoxide and atrazine during the roasting process. Piperonyl butoxide behaved similarly to chlordane, but atrazine disappeared after the roasting process, because it is unstable to heat. (Received October 26, 2011). Source

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