Evaluation of residual levels of benomyl, methyl parathion, diuron, and vamidothion in pineapple pulp and bagasse (smooth cayenne)

The objective of this research was to study the residual levels of benomyl, methyl parathion, diuron, and vamidothion in pineapple bagasse and pulp. Benomyl (benlate), methyl parathion (Folidol 600), diuron (Krovar), and Vamidothion (Kilval 300) were applied pre-harvest to pineapples (smooth cayenne). After harvesting, the fruits were washed (100 ppm sodium hypochlorite) and the pulp was separated from the sub-products (peel, core, tops, and tails). The pulp was not submitted to any heat treatment. The sub-products and the juice expressed from them, were submitted to a blanching process (95 degreesC for 1 min). After separating the juice, the bagasse and pulp were analyzed for residues of diuron and benomyl by high performance liquid chromatography, and for residues of vamidothion and methyl parathion by gas chromatography using a TSD detector. No residues of benomyl, diuron, vamidothion, or methyl parathion were detected in the pulp within the quantification limits of the methods (0.1 mg/kg, 0.1 mg/kg, 0.005 mg/kg, and 0.005 mg/kg, respectively). Only methyl parathion (0.052 mg/kg) and vamidothion (0.021 mg/kg) were detected in the bagasse. The presence of these residues in the bagasse was probably due to the action of the wax found in the peel, which prevented the methyl parathion and vamidothion from dissolving in the juice. According to these results, the pulp was fit for human consumption, as far as pesticide residues were concerned, and the bagasse was fit for animal feed and similar applications, because the residual levels found were below the limits established for these compounds.