Multiclass Pesticide Determination in Olives and Their Processing Factors in Olive Oil: Comparison of Different Olive Oil Extraction Systems

Abstract

The processing factors (pesticide concentration found in olive oil/pesticide concentration found in olives) of azinphos methyl, chlorpyrifos, lambda-cyhalothrin, deltamethrin, diazinon, dimethoate, endosulfan, and fenthion were determined in olive oil production process in various laboratory-scale olive oil extractions based on three- or two-phase centrifugation systems in comparison with samples collected during olive oil extractions in conventional olive mills located at different olive oil production areas in Greece. Pesticide analyses were performed using a multiresidue method developed in our laboratory for the determination of different insecticides and herbicides in olive oil by solid-phase extraction techniques coupled to gas chromatography detection (electron capture detection and nitrogen phosphorus detection), optimized, and validated for olive fruits sample preparation. Processing factors were found to vary among the different pesticides studied. Water addition in the oil extraction procedure (as in a three-phase centrifugation system) was found to decrease the processing factors of dimethoate, alpha-endosulfan, diazinon, and chlorpyrifos, whereas those of fenthion, azinphos methyl, beta-endosulfan, lambda-cyhalothrin, and deltamethrin residues were not affected. The water content of olives processed was found to proportionally affect pesticide processing factors. Fenthion sulfoxide and endosulfan sulfate were the major metabolites of fenthion and endosulfan, respectively, that were detected in laboratory-produced olive oils, but only the concentration of fenthion sulfoxide was found to increase with the increase of water addition in the olive oil extraction process.

Fate of Pesticide Residues on Raw Agricultural Crops after Postharvest Storage and Food Processing to Edible Portions

“…The formation of fenthion sulfoxide during olive oil production was calculated ~5% of the initial fenthion and was correlated with the water addition during oil production process. However, the formation of endosulfan sulphate was not related with the water in oil extraction process (Amvrazi & Albanis, 2008).…”

“…The theoretical processing factors of virgin olive oil by this process range widely (usually range from 4-6) depending on the variety of the olive fruits (oil and water content) and the decanting extraction technology used for oil extraction (Amvrazi & Albanis, 2009;EC, 2005). However, water soluble pesticides such as acephate, dimethoate, methamidophos, omethoate and phosphamidon pass into the aqueous phase during the extraction of oil from olives (Amvrazi & Albanis 2008;Letza-Rizos & Avramides, 1995;Leandri et al, 1993;Ferreira & Tainhan, 1983) and only a small percent is transferred into the oil (e.g. 6.3-8.8% for dimethoate) depending on the water content during the extraction of the olives (Amvrazi & Albanis, 2008).…”

“…However, water soluble pesticides such as acephate, dimethoate, methamidophos, omethoate and phosphamidon pass into the aqueous phase during the extraction of oil from olives (Amvrazi & Albanis 2008;Letza-Rizos & Avramides, 1995;Leandri et al, 1993;Ferreira & Tainhan, 1983) and only a small percent is transferred into the oil (e.g. 6.3-8.8% for dimethoate) depending on the water content during the extraction of the olives (Amvrazi & Albanis, 2008). Other pesticides with lower water solubilities (azinphos methyl, buprofezin, chlorpyrifos, fenthion, deltamethrin, diazinon, endosulfan, quinalphos, -cyhalothrin, methidathion, parathion methyl) were found to concentrate in the oil with a concentration factor of 2-7 (Amvrazi & Albanis 2008;Letza-Rizos & Avramides, 1995;Leandri et al, 1993;Ferreira & Tainhan, 1983) depending on the Kow of the pesticide residue, the oil yield of the extraction procedure and the stability of the pesticide towards volatilization, and hydrolytic and other degradative processes that might take place during the malaxation stage of the procedure.…”

“…6.3-8.8% for dimethoate) depending on the water content during the extraction of the olives (Amvrazi & Albanis, 2008). Other pesticides with lower water solubilities (azinphos methyl, buprofezin, chlorpyrifos, fenthion, deltamethrin, diazinon, endosulfan, quinalphos, -cyhalothrin, methidathion, parathion methyl) were found to concentrate in the oil with a concentration factor of 2-7 (Amvrazi & Albanis 2008;Letza-Rizos & Avramides, 1995;Leandri et al, 1993;Ferreira & Tainhan, 1983) depending on the Kow of the pesticide residue, the oil yield of the extraction procedure and the stability of the pesticide towards volatilization, and hydrolytic and other degradative processes that might take place during the malaxation stage of the procedure. The formation of fenthion sulfoxide during olive oil production was calculated ~5% of the initial fenthion and was correlated with the water addition during oil production process.…”

“…and physicochemical processes (volatilization, absorption etc.). Although these processes usually are leading to reduction of any residues left on crops at harvest (Kaushik et al 2009;Holland et al, 1994), in special cases residues may concentrate in the final product (e.g in the production of dry fruits and unrefined vegetable oil) (Amvrazi & Albanis 2008;Guardia Ruibio et al, 2006;Lentza-Rizos & Avramides, 2006;Lentza-Rizos & Kokkinaki, 2002;Cabras et al, 1997a;Holland et al, 1994;Cabras et al, 1993;Leandri et al, 1993;Ferriera & Tainha, 1983) and/or be formed in more toxic by-products or metabolites of the pesticide parent compound on raw crop (Holland et al, 1994;WHO 1988). These considerations suggest that effects of postharvest practices and food processing should be taken into account on the fate of a pesticide residue during dietary exposure assessments so as to ensure consumer safety from pesticide residues and allow a more realistic calculation of the dietary burden of livestock.…”