Pulsed light processing of foods for microbial safety

Abstract

The demand for processed foods and the awareness about food quality and safety are increasing rapidly. The consumers' demand for minimally processed foods and growing competition in the market have made the processors to adopt newer non-thermal technologies that preserve nutrients and sensory properties of the products. Conventionally, heat processing of foods is carried out to convert raw material into value-added product, reduce or eliminate microbial load to improve safety, and extend shelf life. Some of the limitations of thermal processing techniques can be overcome by employing non-thermal processes. High hydrostatic pressure, pulsed electric field, ultrasound, cold plasma, dense phase carbon dioxide, ozone, and pulsed light (PL) processing are gaining popularity in food processing. PL technology is a non-thermal technology, where sterilization and decontamination are achieved by impinging high-intensity light pulses of short durations on surfaces of foods and high-transmission liquids. Although a few reports on the PL technology are available, in-depth studies on this are needed to adopt at a commercial level. The present review provides an overview of light-based processing of foods and covers important aspects such as different PL systems used for processing of foods, mode of action of PL on microbes, the effect of PL on liquid foods, surface decontamination of foods and parameters that affect PL efficacy, combination processing with PL. With the growing demand in non-thermal processing for the technological advancement in the area of generation of light, light-based processing will be a promising technology for microbial load reduction.