An Overview of the Application of Blue Light-Emitting Diodes as a Non-Thermic Green Technology for Microbial Inactivation in the Food Sector

Abstract

Blue light is an emerging technology used for the decontamination of food contact surfaces and products. It is based on the activation of photosensitizers by light, determining the release of reactive oxygen species (ROS). ROS causes damage to bacterial cells leading to cell death. Several types of microbes may be treated, such as bacteria, yeasts, moulds and viruses, in planktonic or biofilm form. Blue light technology is affected by several factors: light parameters (i.e., irradiance, dose, wavelength), microbial parameters (i.e., pH, temperature, initial inoculum, grade of biofilm maturation) and surface parameters (i.e., material, roughness, and optical properties). In addition, it may be used alone or coupled with other technologies. The use of blue light shows several advantages, such as safety for food operators, and a lower release of chemicals in the environment. Moreover, it seems unlikely for bacteria to develop resistance to the blue light application.

Effectiveness of Ultra-High Irradiance Blue-Light-Emitting Diodes to Control Salmonella Contamination Adhered to Dry Stainless Steel Surfaces

“…In addition to the inactivation induced by photochemical effects, when delivered at high energy densities, blue LEDs may also induce photothermal damage to microbial cells [ 36 , 46 ], thereby contributing to pathogen inactivation. Due to the damage to multiple cellular components, it may be difficult for bacteria to develop resistance to blue-light-based treatments [ 47 ], which makes it a promising intervention to improve food safety.…”

On the Possibility of Using 5-Aminolevulinic Acid in the Light-Induced Destruction of Microorganisms

“…These include natural chemicals such as curcumin, hypericin, and chlorophyllin, as well as classes of pigments such as phenothiazinium, porphyrins, chlorites, and phthalocyanines [14]. Excellent articles [15,16] provide a summary of data on light sources that can be used in aPDI.…”

“…Shemin and Rittenberg presented the first study on the incorporation of nitrogen atoms derived from glycine into heme in 1945. Shemin conducted research on his own heme, ingesting 15 N-labelled glycine which resulted in the 15 N-incorporation into his heme [28].…”