Evaluation of pesticide residue in grape juices and the effect of natural antioxidants on their degradation rate

Abstract

Various studies have been drawn toward the beneficial properties of fruit juices because they have several components, such as phenols, vitamins, and flavonoids, with antioxidant effects. However, fruit juices can also contain residues of pesticides used as standard pest control methods in crops. Many of these pesticides are degraded through oxidative mechanisms, and their persistence in juices can be enhanced by antioxidants. This study covers the degradation of four pesticides, aldicarb, demeton-S-methyl, fenamiphos, and methiocarb, to their respective sulfoxide and sulfone in grape juices, water (pH 3.5) and water (pH 3.5) with quercetin (one of the most important flavonoids of grape) added in an attempt to establish whether the presence of antioxidants can affect the degradation rate of pesticides. For this purpose, a multiresidue method based on solid-phase extraction (SPE) was developed for the simultaneous determination of these pesticides and their metabolites in commercial juices. The extraction procedure was carried out in C(18) columns. The subsequent elution of pesticides was performed with dichloromethane prior to the determination by liquid chromatography-tandem mass spectrometry (LC-MS/MS), using two precursor-product ion transitions. Average recoveries for all the pesticides studied were higher than 80%, with relative standard deviations lower than 15% in the concentration range 0.005-0.05 microg/mL, and the quantification limits achieved ranged from 0.1 to 4.6 microg/L. The results demonstrated that degradation was slower in fruit juices and aqueous solutions with quercetin than in water. Several commercial grape juices were also analyzed to establish the levels of these pesticides. Methiocarb, fenamiphos, and demeton-S-methyl were found at low levels in some samples.

Pesticide residue analysis in parsley, lettuce and spinach by LC-MS/MS

“…Food composition and processing have a significant effect on the dissipation of pesticide residues. Pico and Kozmutza (2007) studied the effect of natural antioxidants Ticha et al (2008) and Fenoll et al (2009b) investigated the dissipation of various insecticides and fungicides in apples and in peppers, respectively. They have reported that pesticide residue contents were decreased during storage.…”

Identification of novel anticancer terpenoids from <i>Prosopis juliflora</i> (Sw) DC (Leguminosae) pods

“…herbal infusions to treat various ailments and serious diseases [5]. P. juliflora is an ornamental traditional medicinal tree.…”

Current mass spectrometry strategies for the analysis of pesticides and their metabolites in food and water matrices

“…The most critical variable in SPE is the selection of the sorbent material. Among the packing materials available, reversed-phase octadecyl silica (RP-C18) (Chusaksri, Sutthivaiyakit, & Sutthivaiyakit, 2006;Hengel & Miller, 2007;Perreau et al, 2007;Picó & Kozmutza, 2007;Pitarch et al, 2007;Rodrigues et al, 2007;Esparza, Moyano, & Galceran, 2009) decyl silica (RP-C8) (Rodrigues et al, 2007), Oasis HLB (Gilbert-López et al, 2007a,b;Potter, Mohamed, & Ali, 2007;García-Reyes et al, 2008;Gervais et al, 2008;Ibáñez et al, 2008;Marín et al, 2009), Oasis MCX , cation exchange/reverse phase mixed-mode Nexus ABS (Hengel & Miller, 2007;Hengel & Miller, 2008), graphitized carbon (Pang et al, 2006b), aminopropyl (-NH 2 ) adsorbents with weak anionexchange and polar capabilities (Pang et al, 2006b;Hengel & Miller, 2008), Florisil (Tahboub, Zaater, & Barri, 2006;Zhang et al, 2006;Rissato et al, 2007;Garrido Frenich, Plaza-Bolaños, & Martínez Vidal, 2008) polystyrene-divinylbenzene materials (Marín et al, 2006;Perreau et al, 2007;Rodrigues et al, 2007;Kuster et al, 2008;Nanita, Pentz, & Bramble, 2009) and carbon-nanotubes (Wang et al, 2007b) have been reported (Tables 1 and 2). Recently, comprehensive studies comparing different SPE packing materials have been carried out in water and food matrices (Rodrigues et al, 2007;González-Rodríguez et al, 2008;…”