The evaluation of Malathion and Diazinon residues in pickled olive during preparation and production.

The use of chemical compounds is a very simple and effective way to protect agricultural products, against pests. Increasing the unplanned use of these pesticides is a concern, because the pesticides residue in fruits and vegetables can lead to very dangerous side effects in humans. Olive is one of the most useful and consuming fruits in the Iranian community that can be used as pickled olive. Therefore, in this study, fermentation ability to reduce residues of two commonly used pesticides, Malathion and Diazinon studied, and their changes due to product acidity, pH and salt content during the preparation and fermentation processes were meassured. The results showed that washing and debittering operations reduced Malathion and Diazinon to 73.59 and 93.38%, respectively. However, after 20 days fermentation, their reduction was 63.68% and 69.57%, and after 40 days, at the end of production, this decrease was approximately 90.5% and 97.98%, respectively. The residue of Malathion pesticide was significantly different in fermentation days; 1, 10 and 20 (P<0.05), while the mean value for Diazinon was not significant. Overall, the results showed that the fermentation process had a significant effect on Malathion residue (P<0.05) but did not affect Diazinon residue. Also, fermentation had a significant effect on the percentage of salt, pH and acidity (P<0.05). At the end of the fermentation process, no mould growing was observed, but the yeast grow was showed (CFU/g 1450), much lower than the number that could affect the quality of the product. Generally, the fermentation process effectively reduced the amount of residual pesticides, and the operations carried out in the production of pickled olives are more effective to reduce the amount of pesticide residues than the fermentation process itself.