Residuos de agrotoxicos em morangos e sua redução por lavagem com agua e estocagem em geladeira (5o.C)

AUTOR(ES)
DATA DE PUBLICAÇÃO

1993

RESUMO

According to good agri cultural pract ice (GAP), the pesticides captan, dicofol and mancozeb were applied in strawberries cultivated in experimental fields in simple and double doses. At 0, 1, 4, 7, 14 and 21 day post-harvest intervals the residues of these pesticides were determined after the fruits were washed in running tap water for 1 minute and after storage under refrigeration (5°C) for 3 and 7 days. In another experiment, strawberries were sampled at the Campinas Supply Center (CEASA), and stored and washed similarly to the ones cultivated in experimental fields. In this case, the residues of chlorothalonil, endosulfan I, endosulfan II and endosulfan sulfate were determined, as well as captan, dicofol and mancozeb. The methodology used for the pesticide analysis included visible spectrophotometry and gas liquid chromatography with an electron capture detector Ni63 and megabore and packed columns. For the cultivated strawberries, the water washings significantly reduced the residue s of captan (20 to 94%), dicofol (10 to 55%) and mancozeb (>90%). The removal of captan and dicofol residues increased proportionally to the residual concentration of the pesticides. The residues decreased with the increase of the post-harvest interval. Dicofol presented the longest persistence, remaining in the fruits for more than 28 days. The washing of the strawberries from CEASA removed 28 to 83% of chlorothaloni! residues and 12 to 94% of captan residues. This treatment did not reduce effectively endosulfan residues. The storage in refrigerator resulted in decrease of captan and mancozeb residues; endosulfan and chlorotha1 onil remained stable under this condition. Twenty six percent of the strawberries sampled at CEASA contained residues of endosulfan and chlorothalonil, which are not permitted for use in this fruit, and 23,3% contained residues of captan, although at levels, below its tolerance. Dicofol and mancozeb we re not detected within the limit of quantification of 0,01 and 0,5 mg/kg, respectively. The similarity between the levels of captan found in the fruits cultivated in t he experimental field and those collected at CEASA suggest that the producers applicated this pesticide according to GAP. The results indicate that the decrease of the contamination of strawberries by pesticides through water washing or storage under refrigeration depends mainly on the type of pesticide used and the magnitude of its residues.

ASSUNTO(S)

morango - armazenamento pesticidas - residuos em alimentos espectrofotometria

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