Investigating the Effect of High Voltage Electric Field on the Pesticide Residue in Tomatoes Using the Thermal Imaging Technique

Providing healthy food for the growing population is one of the most important issues in every country. Pests are one of the main damaging sources of agricultural products. Applying chemical pesticides is a common method employed by growers to address this issue. However, chemical residue not only remains on crops but can also penetrate fruits, vegetables, and even grains. This study aimed to investigate the effect of magnitude and elapsed time of high-voltage electric field (HVEF) application on the reduction of Malathion pesticide residue tissues. Additionally, the possibility of employing thermal imagery to monitor the residual traces of pesticide was evaluated. The effect of the HVEF at four voltage levels, four elapsed periods, and four biological layers of tomato was investigated on the amount of the pesticide residue. In addition to using the thermal imaginary method, the Fourier Transform Infrared spectroscopy (FTIR) method was also used to investigate the reduction of pesticide residues. The results showed that the HVEF significantly reduced the pesticide residue in the 4 kV treatment after 24 h from the time of applying the HVEF. The results of the analysis of FTIR charts and the images obtained from the thermal imaging method showed that the pesticide residue in the product was reduced, and the thermal imaging method can be employed as a low-cost, fast, and reliable method for monitoring the pesticide residue be used. The highest temperature difference between high-voltage treated samples and reference samples in a controlled chamber was 2.1°C at the voltage of 4 kV. By using an HVEF, it is possible to reduce the pesticide residue in tomatoes. The general results show that at a voltage of 4 kV, and 24 h after applying HVEF to the contaminated tomato samples, the maximum amount of pesticide residue has decreased.