Optical technologies for antibacterial control of fresh meat on display

Abstract

Ozone and ultraviolet light are techniques used for microbiological control in foods that use different mechanisms of action to complement their antibacterial action. This study aimed to evaluate the complementarity of these antimicrobial techniques in the food safety of beef contaminated with Escherichia coli. The treatments of aqueous ozone and UV-C were evaluated in cycles, with each cycle having a dose of 69 mJ/cm2 of light and 30 s of ozone spray at a concentration of 0.9 ppm, the time between each cycle was 1 h and repeated ten times. The 1.7 Log total of E. coli reductions corresponds to the colony sum of the amount reduced by treatments from the amount proliferated without treatment. The techniques were also evaluated in isolation, obtaining a significant reduction for UV-C Light and for aqueous ozone it maintained the microbial load controlling proliferation. The organoleptic properties of the meat were evaluated by checking the pH, quantification of proteins, and lipid oxidation. It was observed that the treatments did not cause significant changes in the meat samples, showing that the technologies have the potential to preserve food by avoiding an exponential proliferation of microorganisms without modification of their organoleptic properties.