Wheat detection

TABLE 4.16 Recovery, repeatability, and reproducibility for wheat detection"... 

Major Applications Sol-gel matrix, fuel cells, optical sensors, combustion gas detection system, paints, toys, cleaning products, detergents, textiles, " food freshness sensor, iden-tilying fresh and stale rice, wheat, detecting microorganisms, bacterial growth, psychoactive drug, dental materials ... 

Natural occurrence in wheat Detection of aflatoxin-producing isolates of Aspergillus flavus from wheat... 

In our investigations, we also detected the sorption of isoPO from potato, Arabidopsis and wheat, by calcium pectate. Moreover, we observed the binding with calcium pectate of potato PO from the fraction of proteins ionically bound with cell walls. It is likely that the ability of some PO isoforms to bind with pectin ensures the spatial proximity of these enzymes to the sites of the initiation of lignin synthesis and that these "pectin-specific" isoforms take part in this process. 

Yamakawa, H., Akiyama, H., Endo, Y., Miyatake, K., Sakata, K., Sakai, S., Toyoda, M., and Urisu, A. (2007a). Specific detection of wheat residues in processed foods by polymerase chain reaction. Biosci. Biotechnol. Biochem. 71, 2561-2564. 

In Japan, bifenox is the only registered diphenyl ether herbicide. The tolerance and/or maximum residue limits (MRLs) are established at 0.1 mg kg for cereals such as rice grain, barley and wheat, and 0.05mgkg for potatoes (Ministry of Health, Labour and Welfare, Japan). Ibe California Department of Food and Agriculture (CDFA) established the minimum detectable quantity of diphenyl ether herbicides at 0.1 mgkg for bifenox, nitrofen and oxyfluorfen. ... 

Because acceptable recoveries were obtained at O.Olmgkg", the method LOQ is 0.01 mg kg for flucarbazone-sodium and O.Olmgkg" for Af-desmethyl flucarbazone in all wheat samples. Linearity curves in both solvent and matrix blanks were mn from 0.005 to 0.100 mg kg . Because 0.005 mg kg of each analyte was reliably detected, the method limit of detection (LOD) was 0.005 mg kg in all wheat samples. 

When applied to wheat. Compound A was readily detected in soil samples collected beneath the treated canopy. Compound B was detected only sporadically in soil. Due in part to a greater application volume (1000 vs 300 Lha water) and a higher application rate for Compound B, both compounds were more consistently detected in soil following application to apple foliage. It is often difficult to establish dissipation kinetics under these conditions because as residues in the soil dissipate, additional compound may continue to be deposited on the soil, resulting in a complex, variable dissipation pattern. As a result, it is not always practical or advisable to study soil dissipation in the presence of a crop. 

With the extraction procedure we employed (22), ferulic acid was isolated as the most inhibitory component in wheat straw. There could also be other unknown compounds in the straw which would not be evident with this procedure. In addition, we ignored the possible influence of toxin-producing microorganisms. Microorganisms may have influenced the phytotoxicity exhibited by the aqueous wheat extract in Table IX. Although the present study was not concerned with the phytotoxic effects of microbially decomposed wheat straw, an influence of microbial activity on ferulic acid phytotoxicity was observed. From the results shown in Table XI, it appears that the presence of the prickly sida seed carpel enhanced the inhibitory effects of ferulic acid. In addition to ferulic acid in test solutions containing prickly sida seeds with carpels, a second compound, 4-hydroxy-3-methoxy styrene, was also found to be present. This compound is formed by the decarboxylation of ferulic acid and was produced by a bacterium present on the carpel of prickly sida seed. The decarboxylation of ferulic acid was detected in aqueous solutions of ferulic acid inoculated with the bacterium isolated from the carpels of prickly sida seed. No conversion occurred when the bacterium was not present. 

After use, herbicides decompose slowly, and so affect cultivated plants for many years. In 1990, investigations in many regions of the USSR detected herbicides phytotoxic effects, especially among the si/m-triazine class, on different cultivars in many varied situations [13]. These sym-triazine herbicides, such as protrazin, simazin, atrazine, metazin, and prometrin, were used in different oblasts of the Ukraine, Kirgizia, Kazakhstan, Russia and Moldavia in previous years, especially on corn. Residual herbicide aftereffects led to the suppression and death of crops such as winter wheat, oats, barley, rye, potatoes, beets and sugar beets, linen, onions, watermelons and other melons, and sunflowers. 

Pesticides affect the content of microelements and other substances in plants, thus changing their nutritive value, as well as their ability to be stored. This was detected for OCPs in grain and legume harvests. For example, wheat crops treated with some fungicides (zineb, bayleton, and propicanazol) to fight stem rust (Puccirda) produce a lower quality of bread [3]. 

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