Microbial Decontamination in Saffron (<i>Crocus sativus</i> L.) by Cold Plasma Treatment: An <i>In vitro</i> study

Background & Objective: One of the problems associated with exporting traditional bulk saffron during the harvest season is the uncontrolled microbial load.Hence, it is crucial to discover a suitable method for microbial decontamination.Cold plasma technology is a safe, non-thermal, and efficient approach to deactivating different pathogenic microorganisms in different food or agricultural products.Considering the nutritional and medicinal importance of saffron (Crocus sativus L.), the present research aimed to study the efficacy of cold plasma for decontaminating saffron. Materials & Methods:The cold plasma method was used to treat samples of saffron under various conditions (two different gas types, two different pressures, and two different frequencies, but one power, one exposure time, one gas injection, and one temperature).Subsequently, the treatments' microbial load was measured at a probability level of 1% compared to the control. Results:Our results indicated that the microbial load in the treated samples was reduced by cold plasma technology.The highly effective in reducing microbial load was shown in conditions with cold-vacuumed plasma systems, radio frequency energy (RF) with a 13.56 MHz, pressure at 10 -2 Torr, exposure time of 5 min, injected gas with air and argon (50 L min -1 ), the temperature at 25 o C, and power of 30 W. This treatment was highly effective in decreasing microbial load by 46.6%. Conclusion:Hence, the cold plasma technology can be a risk-free approach to reduce the microbial load in spices, particularly saffron.Ultimately, our in vitro results introduce an optimized conditions and primary information for future research on the industrial decontamination of medicinal plants.