Applications, Challenges, and Future Trends in Using Light-Based Technologies for Low-Moisture Foods...

Low-moisture foods (LMFs) are prone to microbial contamination. Thermal treatments, although effective, could compromise LMFs quality. Hence, interest in alternative decontamination strategies such as light-based treatments has increased. This manuscript aims to provide insights into using light-based decontamination technologies in LMFs processing by reviewing the 1) microbial contamination issues affecting LMFs, 2) application, mechanisms of action, and process factors affecting light-based decontamination efficacy, and 3) potential challenges and future directions on establishing light-based technologies as a standard LMFs decontamination step. Pathogenic microorganism contamination of LMFs has been well documented in the existing literature. The use of LEDs, UV, and pulsed light (PL) in diverse LMFs categories produced reductions ranging from 0.7 to 4.0. These reductions were facilitated by induced inactivation mechanisms including ROS generation, cell membrane damage, DNA damage, and localized heating. The decontamination efficacy of LEDs, UV, and PL treatments was also affected by factors such as target microorganism, processing conditions, and inherent food matrix characteristics of treated LMFs. The review findings also found critical gaps that need to be addressed such as 1) lack of standardized experiment/validation methodologies, 2) inadequate exposure of LMFs due to shadowing/obstruction, 3) sub-optimal process and light delivery engineering, 4) lack of process validations on scaled-up/commercial equipment, and 5) insufficient techno-economic assessments on cost-effectiveness and throughput capability. The review findings indicate that light-based technologies can be a viable alternative decontamination step for LMFs although they have critical limitations to be addressed before being fully usable in LMFs processing.