Pulsed infrared effect on Aspergillus flavus spores decontamination in saffron

Abstract

This study investigated the effect of pulsed infrared (PIR) radiation as a novel thermal process (low energy consumption) on the decontamination of A spergillus flavus (A. flavus) spores in saffron. Some physicochemical properties including energy consumption, antioxidant activity, total phenolic content, and overall saffron quality. The experimental parameters included PIR power levels (250, 350, and 450 W), sample distances from the radiation source (10, 20, and 30 cm), treatment time (0–20 min), and PIR pulse (1, 2, and 3 pulses/s). Optimal conditions were identified at 350 W PIR power, 10 cm distance, 1.5 min of irradiation, and a pulse frequency of 3 pulses/s, achieving a maximum reduction of 3.769 Log CFU/g (%76.92 reduction) in A. flavus spores. It was observed that PIR utilizes 50% less energy than IR due to its pulsed nature, making it an energy-efficient method. PIR had a less pronounced (%28.8 less) effect on the IC₅₀ of Sargol Negin saffron compared to IR (P < 0.05). The Double Weibull model provided the best fit for predicting microbial population dynamics. Before this study, the application of PIR for decontamination of A. flavus spores in saffron had not been reported. The findings suggest that the PIR method effectively reduce microbial contamination while maintaining the quality of saffron, making it a viable option for ensuring food safety and quality.