Drenaje agricola

Food Chemistry 65 (1999) 509±514

Behavior of pesticides in tomatoes during commercial and home preparation
A.A.K. Abou-Arab
Food Technology Department, National Research Center, Dokki, Cairo, Egypt Received 30 June 1998; accepted 28 September 1998

Abstract Monitoring of pesticide residues in Egyptian tomatoes and its products was studied. The average contents of HCB, lindane, dieldrin,heptachlor epoxide and DDT derivatives were detected at levels 0.009, 0.003, 0.006, 0.008 and 0.083 mg/kg, respectively. On the other hand, the levels of dimethoate, profenofos and pirimiphos-methyl were 0.461, 0.206 and 0.114 mg/kg, respectively. In ketchup and paste samples, most organochlorine and organophosphorus pesticide residues were not detectable. The distribution patterns of pesticideresidues within the cuticular and subcuticular tissues in tomatoes were also studied. The skin samples were found to contain the highest levels of HCB, lindane, dieldrin and DDT derivatives. The investigation also indicated that washing with water and/or detergent solution were necessary to decrease the intake of pesticide residues. Freezing, as well as juicing and peeling, were necessary toremove pesticide residues in the skin. Cooking of tomatoes (including processing tomato to paste) helped to eliminate most pesticide residues from contaminated tomatoes. # 1999 Published by Elsevier Science Ltd. All rights reserved.

1. Introduciton Vegetables and fruits are susceptible to insect and disease attacks, so pesticides are widely used. Therefore, residues of pesticide could e€ect theultimate consumers especially when freshly consumed. Many studies were carried out on pesticide residues in vegetables and fruits. It was reported that the main residues were HCB, lindane, heptachlor and its epoxide, DDT and its derivatives, as well as malathion, pirimiphos-methyl, profenofos and dimethoate (Abou-Arab, Soliman, Amra, & Naguib, 1995; Abou-El-Ghar, 1961; El-Lakwah, Hamed, Darwish,& Shams El-Din, 1995). Tomato fruits are considered to be an important crop in Egypt. The average yield per feddan is relatively low under the Egyptian conditions and this may be due to many factors, including insect infestation (El-Nabarawy, Abou-Donia, & Amra, 1992). The objectives of this study were to study: (1) the levels of pesticide residues in Egyptian tomatoes and its products; (2)distribution pattern of pesticide residues within the cuticular and subcuticular tissues of tomato fruits, and, (3) e€ect of washing procedures well as processing of tomatoes, on pesticide residues.

2. Materials and Methods 2.1. Samples Fifty tomato fruit samples and 25 samples of each ketchup and paste were collected randomly from di€erent regions in Great Cairo Governorate (Cairo, Giza andKalubia). To study the distribution pattern of pesticide residues within the di€erent tissues of the contaminated tomatoes, 25 samples each of skin, pulp, seeds, and juice were collected. Washing by acetic acid and sodium chloride at levels of 2, 4, 6, 8 and 10%, as well as tap water, freezing at À10 C (for 1, 3, 6, and 12 days), juicing, peeling, and home canning at 100 C for 30 min, wereapplied to tomato fruit samples polluted by HCB, lindane, p.p-DDT, dimethoate, profenofos and pirimiphos-methyl at levels about 1.0 mg/kg. 2.2. Standards Pesticide standards of hexachlorobenzene (HCB), lindane, aldrin, dieldrin, heptachlor, heptachlor epoxide; chlordane, Endrin, 1,1,1-tri-chloro-2,2 bis (p-chlorophenyl) ethane (p.p- DDT); 1-(o-chlorophenyl)-1-(p-

0308-8146/99/$ - see front matter #1999 Published by Elsevier Science Ltd. All rights reserved. PII: S0308 -8 146(98)00231 -3

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A.A.K. Abou-Arab / Food Chemistry 65 (1999) 509±514

chlorophenyl)-2,2,2-tri-chloroethane (o. p-DDT), 1, 1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p. p-DDE), 1(o-chlorophenyl)-1-(p-chlorophenyl)-2,2-dichloro-ethylene (o.p-DDE), 1,1-di-chloro -2,2 bis (p-chloro-phenyl) ethane (p.p-DDD),...