Organophosphorus pesticides are widely used as insecticides and herbicides in agriculture for the control of various insects and weeds. These pesticides are decomposed by various natural conditions in the environment : by hydrolysis, photodegradation on surface of plant, metabolism in plants, and bacteriological degradation in soil. The degradation products of pesticides are potentially ingested by humans with eating agricultural products. In some cases, the toxicity of degradation products shows higher toxicity than the parent compound. Therefore, understanding of degradation pathways of pesticides after their release into the environment is necessary and also evaluation of toxicity of these degradation products is important. This review introduces typically physical degradation patterns of Organophosphorus insecticides in order to know their environmental fate. And furthermore, we focused the photodegradation that is one of the most important factors involved in decomposition of pesticide in the environment. In this review, we introduce the photodegradation mechanism of the Organophosphorus insecticide fenthion in an aqueous solution under UVB irradiation (280-320 nm radiation). Fenthion is photodecomposed by a couple of mechanisms : one is photochemical hydrolysis to form 3-methyl-4-methylthiophenol (MMTP) and dimethyl phosphorothioate, and the other is photo-oxygenation triggered by singlet oxygen (¹O₂) and producing fenthion sulfoxide and 3-methyl-4-methylthiophenol (MMSP). The steady photodegradation products of fenthion in environment were elucidated to be fenthion sulfoxide and MMSP. This review suggests that the toxicological evaluation of degradation products of pesticides is necessary as well as parent pesticide from the viewpoint of human health effect.

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We studied the degradation and fragmentation of DNA molecules of corn during different food production processes. Grits prepared from the genetically modified (GM) corn varieties MON810 and GA21 were processed by frying or using an extruder, a device that treats a slurry of grits with both heating and pressure, followed by a sudden release of pressure to atmospheric conditions through a pinhole, to produce corn snacks. DNA fragments longer than 600 bp could be amplified by PCR for the genomic DNA prepared from fried processed corn grits at temperatures lower than 160℃ for 1 min, while those shorter than 400 bp could be detected from processed grits at 180℃. However, even at 128℃, extruder processing caused severe fragmentation of genomic DNA fragments shorter than 197 bp, and at much higher temperatures no amplified fragments longer than 100 bp could be detected. Grits derived from the GM corn varieties MON810 and GA21 were processed with an extruder at 128℃, and genomic DNAs were prepared from the processed grits. Each transgene of these GM corns and the cornstarch synthase lib (SSIIb) gene, which is used as the control gene for the Japanese official quantification method, were quantified by quantitative TaqMan PCR. The copy number of the SSIIb gene in the processed grits was smaller than that of the transgenes of both MON810 and GA21, which indicated that the SSIIb gene would be easier to fragment than the transgenes with extruder processing. Therefore, the ratio of the copy number of the transgene per internal control SSIIb gene in the processed corn snacks using the extruder might be higher than in the raw materials of corn grits using quantitative TaqMan methods.

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A Rapid GC/MS/MS method was developed using a 10 m-length short column for multi-residue determination of pesticides in agricultural products. Using this method, more than 50 pesticides were successfully analyzed within 8 min. Besides, 107 pesticides were determined in 28 min by the combination of two methods which had independent MS/MS parameters. The method was validated for 107 pesticides at three spike levels (0.01, 0.02, 0.05μg/mL) in five matrices from either spinach, carrot, onion, brown rice or grape fruits. Relationship between the concentration and peak area of each pesticide was linear (r² > 0.92, except for Dieldrin in carrot matrix). The quantification limits were lower than 0.01μg/mL except for Dieldrin and Silafluofen in carrot matrix.

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Genetic variability between the red radish population imported from Yunnan province of China and the population visibly selected three times by anthocyanin content in the field after importation to Japan was analyzed based on AFLP method. Consequently, these two populations formed one group in a phylogenetic tree and no significant difference was found on their nucleotide diversity. These findings presumed us to allow both kinds of seeds to provide for crossing experiment without taking their genetic variability into consideration.

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An HPLC method for the analysis of water-soluble annatto in food was established. Water-soluble annatto was extracted from food samples with 1 % ammonia-70 % ethanol and the extract was then purified with a CIS cartridge after evaporation of ethanol before being subjected to the HPLC analysis. The HPLC conditions were as follows: column, TOSOH TSK gel ODS-80Ts (5μm, 4.6×250 mm) ; column temperature, 40℃ ; mobile phase, acetonitrile-0.01 mol/L trifluoracetic acid (74 : 25) ; flow rate, 1.0 mL/min ; detection wavelength, 454 nm. The average recoveries of the water-soluble annatto were over 71 % from juice and jelly fortified at the concentrations of 1000μg/g. The coefficients of variation were less than 5.3 %. The present method is considered to be useful for the analysis of water-soluble annatto in foods.

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A convenient method for determining erucic (cis-13-docosenoic) acid content in individual seeds of rape is presented. Fatty acid methyl esters were prepared from naked cotyledon (including hypocotyl) of single seeds and were analyzed by high-speed gas chromatography. This method consists of two steps : 1) using rapid methanolysis directly on seed tissue and 2) employing high-speed gas chromatography. Hence, a single seed can be tested in less than ten minutes. This method was used to analyze seeds from high-, low-, and zero-erucic-acid varieties of rape. We found that almost all the seeds from low-erucic-acid varieties produced no erucic acid and a few seeds produced erucic acid.

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