Combining UV-C technology and caffeine application to inactivate Escherichia coli on chicken breast fillets

Abstract

Chicken breast meat is an important vehicle of pathogenic Escherichia coli, which raises public health concerns. The objective of this study was to evaluate and model the combined effects of caffeine and UV-C irradiation on E. coli levels on raw chicken breast fillets. Chicken breast samples were pre-treated with different concentrations of caffeine (0–20 mM/g), inoculated with E. coli (ca. 107-108 cfu/g), and submitted to UV-C irradiation at doses ranging from 0 to 15 J/cm2. E. coli inactivation increased by increasing both caffeine concentrations and UV-C doses. Reductions of more than 5-logs were observed in caffeine-free samples at UV-C doses higher than 12 J/cm2, while the pre-treatment of samples with caffeine at 20 mM/g resulted in undetectable levels of E. coli after UV-C treatments at doses higher than 6 J/cm2. The Weibull model coupled with a linear secondary model was suitable to fit the inactivation data (RMSE = 0.48, R2adj = 0.95) and can be used to predict E. coli inactivation as a function of caffeine concentrations and UV-C doses. Thus, the model generated in this study can be applied by food-business operators for decision-making and for process optimization. Overall, the results derived from this study revealed that caffeine application on chicken breast samples helps to reduce the UV-C doses required to reach desired levels of E. coli inactivation.