Tests on three common food-borne pathogens (Listeria monocytogenes, a strain of Escherichia coli and Salmonella typhimurium) found that the sterilising effect of blue light was most harmful to L. monocytogenes under acidic conditions, while both alkaline and acidic conditions enhanced the effect on the other two.
A previous study by the same team found that blue LEDs' antibacterial potential was greatest at temperatures of 4-15 degsC.
Research team leader Assistant Professor Yuk Hyun-Gyun said: "Taken together, our two studies point to a potential for preserving acidic foods in combination with chilling temperatures without chemical treatments.
"The next step for us is to apply this LED technology to real food samples such as fresh-cut fruits to investigate whether it can effectively kill pathogenic bacteria without deterioration of food products." The findings were published in the journal Food Microbiology.