Postharvest plasma treatment of Barhi dates: Reducing pesticide residue while preserving nutritional value

Abstract

Pesticide residues are available in a broad range of fruits, vegetables, and foods which leave harmful effects on health and environmental sustainability. Most agricultural products exposed to pesticides are marketed shortly after spraying. Palm growers widely use Abamectin and Fenpyroximate to control spider mites. After spraying, some date cultivars such as Barhi date are mostly used as fresh fruit by the consumer without passing the pre-harvest interval (PHI). The efficacy of Gliding Arc Discharge Plasma (GADP) on the degradation of Abamectin and Fenpyroximate pesticides was investigated. The GADP irradiation treatment included 0, 30, 60, 90, and 120s irradiation times applied on the surface of Barhi date fruits sprayed with Abamectin and Fenpyroximate at three different concentrations. The amount of mineral elements, total carbohydrate content, pH, microbial load, Abamectin and Fenpyroximate residue, and optical emission spectroscopy (OES) of plasma were measured. The ANOVA indicated that the impact of the irradiation times was significant on the residue amount of the pesticides in the Khalal stage. The potassium content of Barhi date fruit increased after GADP treatment. Although there were few alterations in the levels of P, Mg, total carbohydrate, and pH. Results show that the microbial load decreased significantly after plasma treatment whilst the lowest microbial load belongs to 120s treatment. Results achieved the largest degradation efficiency of pesticides at 1 ml/L, up to 89.4% and 89.3%, respectively during 120s GADP treatment. Also, the results showed that the degradation efficiency increased with an increase in the treatment time. This study demonstrates effective pesticide degradation in the Barhi date Khalal stage while meeting the Maximum Residue Limit (MRL) criteria. Thus, cold plasma technology presents a promising approach to enhance food safety through effective pesticide degradation on fruit surfaces whilst preserving the fruits' essential mineral content, quality, and extending their shelf life by reducing microbial contamination.