Utilization of Intense Pulsed Light for the Microbial Decontamination of Low-Moisture Foods

Abstract

This work aimed to develop a continuous intense pulsed light (IPL) system for the nonthermal pasteurization of low-moisture foods (LMFs). In the last few years, LMFs have been implicated in multiple foodborne outbreaks and caused severe illness in thousands of people. This system should aid in the reduction of food recalls and to assist the food industry to meet the rising consumer demands for safe, minimally processed foods. The approach included evaluating various inoculation methodologies to understand how each one impacts the desiccation tolerance and homogeneity of bacteria following sample equilibration, identifying various treatment parameters and how they affect the efficacy of IPL to eliminate pathogenic bacteria in LMFs, and finally to test the treatment parameters from powdered foods and apply them to a larger, more irregularly shaped food matrix. The results show that IPL can be used to rapidly decontaminate different types of LMFs. Treatment times of less than 30 seconds resulted in ~3-log reduction of Cronobacter sakazakii in nonfat dry milk, and treatment times of 120 seconds resulted in at least a 1.5-log reduction on most microorganisms in hard red wheat (HRW). Results indicate that, especially in HRW, treatment times can be extended without negatively impacting functional properties.