Dissipation of pesticides during bread-making

In the light of recent increased interest in obtaining data on fate of pesticide residues during processing of food commodities for the more realistic estimates of the dietary intake of the pesticides, the present study was carried out to investigate the dissipation of pesticides during bread-making and the effect of pesticide contamination in the substrate on yeast growth required to mediate the fermentation. The bread was prepared from wheat flour spiked at different concentrations (1, 2, 3 and 4 mg/kg) with six pesticides (endosulfan, hexaconazole, propiaconazole, malathion, chlorpyriphos and deltamethrin) belonging to different chemical families. A simple, rapid analytical procedure for the quantification of analytes of interest in the matrix was developed using gas chromatography with electron capture detector. During bread-making process, considerable loss of pesticides (47–89%) was observed. Pesticide degradation during the process showed negative correlation with concentration of pesticides in wheat flour. The presence of endosulfan, hexaconazole and propiaconazole in the matrix suppressed the growth of the yeast in the range 7.5–33.5%, 12.5–44.7% and 11–40%, respectively. Other pesticides (malathion, chlorpyriphos and deltamethrin) did not show any significant effect on yeast growth. This kind of study is among the critical supporting studies required for the more realistic estimates to be made of the dietary intake of the pesticides and would help formulating regulatory guidelines for management of residues on such products by fixing or re-evaluating MRLs for their quality assurance and control.