Catalytic Infrared Promoted the Decontamination of Intense Pulsed Light on Green Sichuan Pepper (Zanthoxylum schinifolium)

Abstract

Intense pulsed light (IPL) is an efficient sterilization technology for instantaneous intense UV predominantly, while the decontamination was weakened on green Sichuan pepper (GSP) for “shadow effect.” Catalytic infrared (CIR) has excellent decontamination on uneven surfaces for long-wave diffraction while was prone to cause flavor decline for “thermal effect.” In this study, a combined method of CIR and IPL was attempted to settle the dispute of decontamination effect and flavor decline on GSP. The inactivation kinetics on the change of bacterial enumeration over sterilization time were determined, and the results showed the sterilization effect of IPL on GSP could be improved significantly after CIR pretreatment, which was promoted from 0.65 ± 0.07 to 2.62 ± 0.07 Lg (p < 0.05), and could realize the active bacteria on commercial GSP was below 100 CFU g⁻¹. Moreover, the flavor of GSP was measured on color and aroma changes, volatile oil content, and total alkaloid content, and the antioxidant function was measured on total reducing power, ABTS^+•, and ^•OH⁻ clearance rates. The results showed CIR could give rise to color change and volatile oil decrease of GSP, which indicated that the treatment time of CIR should be restricted in 5 min based on relevant Chinese national standard. CIR and IPL showed a difference to several oxygen free radicals, and the impact could be weakened by a combined method. In conclusion, under the same sterilization rate, CIR pretreatment could promote the decontamination of IPL on GSP and could weaken the influence of CIR or IPL on the quality of GSP.