Here is biologically how the lighting interacts with the pathogens or unwanted cells:
Bacterial cells contain light sensitive compounds that adsorb light in the visible region of the electromagnetic spectrum (400-430 nm), which is mainly blue LED light. Exposure to illumination from blue LED light can start off a process within the cells that ultimately causes the cells to die.
Existing studies on the antibacterial effect of LED illumination evaluated its efficacy by adding photosensitisers to the food samples, or by using a close distance of less than 2 cm between the bacterial suspension and LED light source. These conditions would not be viable for application on food preservation.
Often times the best part of science is that you can use your mind to go beyond the neat factor to actual practical applications.
And below is a cool video of a blue led cube (not sure if this one would work for food but it’s fun!)
thanks to ledlighting-eetimes.com for the great info