Development of a predictive model for the reduction of Escherichia coli on the surface of materials as a function of concentration and treatment time with ethanol

Abstract

The purpose of this study was to develop a model that could predict the reduction of Escherichia coli on different surfaces treated with ethanol as a function of concentration and treatment time. The reduction in E. coli on the surfaces of stainless steel, plastic, wood, rubber, glass, and ceramic at various ethanol concentrations (0-70%) after 0-5 min treatment times were evaluated. The contamination levels of E. coli were reduced to 6.73, 5.49, 4.68, 6.38, 5.40, and 6.30 log CFU/cm(2) on the surface of stainless steel, plastic, wood, rubber, glass, and ceramic, respectively, when treated with a maximum concentration (70%) of ethanol for 5 min. Each predictive model was significant (p < 0.05) and the fitness was defined by the lack of fit and probability of normal residuals. Therefore, these models could be used to determine the minimum required ethanol concentrations and treatment times to control E. coli on the surface of various materials.