Chlorpyrifos residue reduction in pistachios using a saponin-rich extract from Saponaria officinalis: An eco-friendly washing approach

• Soapwort extract significantly reduced chlorpyrifos residues in pistachios. • Up to 81% residue reduction achieved using optimized washing conditions. • Saponin-based washing outperformed tap water (12–22% removal). • Optimal treatments: 10% extract for dry nuts, 5% for fresh pistachios. • Eco-friendly biosurfactant wash works effectively at ambient temperature. The widespread use of pesticides in agriculture raises serious food safety concerns due to the persistence of chemical residues in food products. Chlorpyrifos, an organophosphate insecticide, is frequently detected in pistachios and has been reported to exceed maximum residue limits (MRLs) in some cases, posing both health and trade challenges. This study evaluated the effectiveness of a saponin-rich extract from Saponaria officinalis (soapwort) as a natural decontamination agent for reducing chlorpyrifos residues in pistachios. Triplicate pistachio samples (20 g each; Group A: pistachios with hard shells; Group B: fresh pistachios with green hulls) were artificially contaminated with chlorpyrifos and washed under varying conditions of extract concentration (2%, 5%, 10%), washing time (5, 10, 15 min), and temperature (25–55 ° C). Gas chromatography with electron capture detection (GC-ECD) was used for quantification, and UHPLC-MS/MS was used to validate results. Optimal conditions were identified as 10% extract for 15 min in Group A and 5% extract for 15 min in Group B, resulting in 81% and 74.2% reductions in residue, respectively. Washing with water alone achieved only a 12–22% reduction. Increasing the extract concentration beyond 5% in Group B even decreased efficiency., confirming 25 ° C as optimal. UHPLC-MS/MS validation confirmed reductions in residue levels up to 77.4% under optimized conditions. These findings highlight soapwort extract as a promising, eco-friendly alternative to conventional washing methods for pistachios, offering a safe and cost-effective approach that adheres to international residue standards.