Impact of chemical pesticides on antioxidant constituents and free radical scavenging capacity of pesticide-treated tomato (Solanum lycopersicum L.) fruits

Abstract

Tomato fruits are well-known with abundant antioxidants. However, they are often susceptible to pest attacks. To prevent spoilage, tomato fruits are sprayed with pesticides postharvest. On this basis, the study was conducted to examined impact of pesticide on antioxidant constituents of tomato fruits preserved under pesticides alongside other alternative preservative methods. Tomato fruits grown in a soil-free pesticides were divided into five groups, and each was preserved using different techniques: pesticide spray, freezing, drying, parboiling, and in distilled water which served as a normal control. A mixture of hexane, ethanol, and acetone (2:1:1) was used to extract antioxidant molecules from tomato fruits; the hexane fraction obtained was used to determine the concentration of lycopene, β-carotene, and Vitamins A, C, and E. Antioxidant activities were also investigated. The results of the study revealed that all the methods used in preserving tomato fruit cause alteration in antioxidant molecules, Lycopene in preserved fruits is ≤2.52±0.89mg/g FW (fresh weight) compared to 5.07±0.08mg/g FW (normal control), and β-carotene; ≤1.49±0.09mg/g FW compared to 2.99±0.23mg/g FW (normal control). Vitamin A declined from 30.30±1.79 mg/100g extract (normal control) to ≤28.25±0.49 mg/100g extract (preserved fruits). Vitamin E in normal control is 5.07±0.08 mg/100g extract, declining to ≤4.86±0.04 mg/100g extract (preserved fruits). DPPH radical scavenging by fruits preserved under pesticide is 61–70%; other methods is 70–75%; normal control (81.53%); and ascorbic acid (88.50%). In conclusion, preservation of tomato fruits causes a decline in antioxidant molecules, with pesticides causing a greater loss compared to methods like freezing, drying, and parboiling.