Chlorpyrifos Pesticide Removal from Black Grapes Using Plasma-Activated Water Produced by Plasma Bubbling Technology

Abstract

This study is aimed at evaluating the ability of plasma-activated water (PAW) to reduce the chlorpyrifos pesticide residue in black grapes. Raw black grapes were spiked with a known concentration (10, 15, and 20 ppm) of chlorpyrifos (20% EC) and bubbled with 120 V air plasma at three different time intervals (5, 10, and 15 min). GC-MS analysis of these plasma-bubbled grapes showed up to 65.25% reduction (20 ppm sample) in chlorpyrifos content after 15 min of treatment. However, the treatment also reduced the grape juice’s ascorbic acid ($19.97\pm 2.69$ to $9.15\pm 2.02$ mg/ml), antioxidant scavenging activity ($77.42\pm 2.97$ to $53.30\pm 4.77\%$), total flavonoids ($3.00\pm 0.53$ to $2.61\pm 0.57$ mg QE/ml), total soluble solids ($14.23\pm 1.96$ to $11.95\pm 1.86$°), total suspended solids ($1.95\pm 0.16$ to $1.80\pm 0.03$ g/l), and turbidity ($246.63\pm 11.42$ to $224.1\pm 24.85$ NTU). Meanwhile, other physicochemical attributes such as pH, titrable acidity, total phenol content, color index, and texture values had slight changes after plasma bubbling. Thus, plasma bubbling proved to be an effective method to remove the chlorpyrifos pesticide present in grapes, and the techniques also preserve the quality of the commodity.