Development of a Test Method for Analyzing the Hygienic Performance of Commercial Dishwashers Operating on the Fresh Water Principle

Abstract

In recent years, the aspect of hygiene has become increasingly important in all areas of daily life. Especially in the areas of gastronomy, nursing homes, kindergartens and hospitals, the hygiene aspect is of particular importance. This study deals with the examination of the hygienic performance of commercial dishwashers with a water replacement system (fresh water dishwashers) using Micrococcus luteus DSM 1790 and the carrier material oat flakes as test soil. After rinsing, the soil is detached from the test items using an elution solution. Furthermore, the sump and the back and side walls of the commercial fresh water dishwasher were examined by contact plates to obtain the microbial count. This approach has been tested for functionality in a series of empirical experiments. In addition, the influence of various commercial detergents on results was examined. It was found that the newly developed method emphasizes the difference between the tested programs. Furthermore, it was found that using a program with longer holding times led to a higher germ reduction in the upper basket than in the lower basket.