Comparison of saffron treated by plasma and gamma irradiation as a novel technique for pesticide residue reduction

This study evaluated the impact of cold plasma technology on microbial, chemical, and pesticide residues in saffron compared to gamma-ray irradiation. Three types of cold plasma, including DBD, FE-DBD, and PECVD, as well as gamma irradiation (10 kGy), were applied to saffron samples. The results first demonstrated that all plasma treatments and gamma irradiation significantly ( p < 0.05) reduced the total microbial load of saffron, with cold plasma showing superior performance in pesticide residue reduction, including insecticides, fungicides, herbicides, and acaricides. However, these decontamination benefits were accompanied by trade-offs in chemical quality: crocin and picrocin levels decreased significantly ( p < 0.05) under both plasma and gamma treatments, while safranal content remained unchanged ( p ≥ 0.05). Regarding antioxidant activity, PECVD plasma caused a significant decrease, gamma irradiation caused a significant increase, and DBD and FE-DBD plasmas showed no significant effect. Both plasma and gamma treatments led to a slight but non-significant increase in total phenolic compounds. Overall, this study suggests that cold plasma, as a novel technology, not only ensures effective decontamination but, due to its non-thermal and non-chemical nature, can be considered a safer and more sustainable alternative to conventional irradiation methods such as gamma irradiation, because, unlike gamma rays, it avoids the potential formation of toxic intermediates while effectively reducing microbial contaminants. • Cold plasma treatments (DBD, FE-DBD, PECVD), similar to gamma irradiation (10 kGy) as a conventional method, were efficient for microbial decontamination of saffron. • Cold plasma proved to be a safer alternative as it is a non-thermal process without radioactive by-products and with better preservation of saffron metabolites. • Cold plasma and gamma irradiation treatments demonstrated dual efficacy in reducing microbial and chemical contaminants, without a noticeable impact on saffron’s antioxidant compounds .