UV-C irradiation as an alternative treatment technique: Study of its effect on microbial inactivation, cytotoxicity, and sensory properties in cranberry-flavored water

The impact of UV-C irradiation at 254 nm on microbial inactivation, cytotoxicity, and sensory properties of cranberry-flavored water (CFW) was studied using a continuous flow-through system. Two different bacterial outbreak strains, Escherichia coli ATCC 700728 and Salmonella enterica serovar Muenchen ATCC BAA 1764, were inactivated by > 5 log(10) CFU/mL at an UV-C fluence of 12 mJ.cm(-2) and 16 mJ.cm(-2) from an initial concentration of approximately 8 log CFU.mL(-1) with D values of 2.11 and 3.14 mJ.cm(-2), respectively. Cytotoxicity evaluation of CFW in human endothelial cells (EA.hy926) demonstrated no toxic effects up to a maximum delivered UV-C fluence of 120 mJ.cm(-2). Quantitative Descriptive Analysis (QDA) was performed to evaluate the sensory attributes of UV-C irradiated CFW at two (30 and 120 mJ.cm(-2)) UV-C fluence levels. Our results suggested that UV-C irradiated CFW had no significant difference (p > 0.05) in sensory attributes up to a fluence of 30 mJ.cm(-2) which is below the FDA-recommended UV-C fluence (40 mJ.cm(-2)) for the inactivation of E. coli and Salmonella. Overall, this research suggests that UV-C treatment of CFW can achieve effective microbial inactivation, without the generation of cytotoxic effects, and also can retain its sensory attributes. These results demonstrated that UV-C irradiation can be an alternative treatment technique in processing of beverages while maintaining food safety and quality.