Evaluation Of Ozone Treatment for Reduction of Pesticide Residues in Guntur Chilli (Capsicum Annuum L.)

Guntur chilli (Capsicum annuum L.) is one of India’s most important spice crops, contributing around 25% of global chilli production and supporting a significant export market. However, the widespread and frequently unregulated use of organophosphate pesticides—especially ethion—during farming raises serious food safety concerns, as residue levels commonly surpass the 0.5 mg kg⁻¹ maximum limit set by the Food Safety and Standards Authority of India (FSSAI). This study investigated the potential of ozone (O₃) treatment as a non-thermal, eco-friendly method to reduce both ethion residues and aflatoxin contamination in dried whole and ground Guntur chilli.
Chilli samples were contaminated with ethion at 9.918 mg kg⁻¹ and exposed to ozone generated by a Faraday high-concentration unit operating at full capacity with an airflow of 14 LPM, for durations ranging from 3 to 8 hours. Residual pesticide levels were measured using Gas Chromatography–Mass Spectrometry (GC-MS). Colour changes were assessed using a Konica Minolta CM-5 spectrophotometer under the CIELAB system (L, a, b), while HPLC with fluorescence detection was employed to evaluate aflatoxin reduction. Additionally, proximate analysis—focusing on ash and moisture content—was conducted to determine any effects on
nutritional quality.
Ozone treatment successfully lowers the levels of compounds detected via GC-MS, but its effectiveness changes in a non-linear manner over time. The pattern of results showing alternating decreases and increases points to a complex degradation process involving multiple stages. An 8-hour exposure yields the best outcome, achieving a peak reduction of 40.27%. Colour measurements revealed minimal impact on visual quality, with the 5-hour exposure yielding the best retention of natural colour. Aflatoxin levels dropped by as much as 83.57% following 7 hours of ozonation, highlighting the method’s effectiveness against multiple contaminants. Ash content remained within FSSAI standards across all samples, indicating no adverse effect on the product’s physicochemical properties.
The findings demonstrate that ozone treatment is a promising, chemical-free, and scalable post-harvest solution for reducing pesticide and mycotoxin loads in dried chillies. It offers practical benefits for meeting food safety regulations, enhancing consumer protection, and supporting the sustainability of India’s chilli export industry.