Noelle Wrubbel

Potentials and Impacts of Low Temperature Electric Household Dishwashing

Abstract To further reduce energy consumption of dishwashing programmes and still obtain satisfying cleaning results, water temperatures in the programme steps are decreased and running times are prolonged. To which extent the cleaning factor duration is able to compensate for temperature has been insufficiently researched until now. This study quantifies the effects of a pre-rinse step, of the duration and water temperatures in different dishwashing programme steps on the cleaning performance and energy consumption in mathematical models. Using those models it is shown that even a (cold) pre-rinse step increases the cleaning performance and that energy consumption is reduced by 25–28% and the cleaning performance decreases, especially on heavily soiled load items and of fatty soilings on plastic surfaces, if the water temperature in the cleaning step is lowered to 30°C.

Qualitative and Quantitative Analysis of Microbial Communities in Household Dishwashers in Germany

Abstract The proper cleaning of used dishes provides an essential means to maintain a sufficient hygiene level on food contact surfaces. However, little is known on the microbiological quality of domestic dishwashers themselves, especially in relation to consumer habits. This study investigated dishwashers in German households to analyse the number and composition of microbial colonisers and their putative impact on dishwashing hygiene. Although the microbiological status of dishwashers appeared to depend on multiple factors, data suggest that a trend towards lower temperatures might effect in a decreased hygiene.

Effects of Relevant Detergent Components on the Cleaning Performance in Low Temperature Electric Household Dishwashing

Abstract Lowering water temperatures in the cleaning step of a dishwashing program to 30°C leads to reduced energy consumption and decreased cleaning performances on persistently soiled dish- and cookware and of fatty soilings on hydrophobic surfaces. This study focusses on the question if the observed decline of the cleaning performance can be compensated for by aligning the formulation of the dishwashing detergent. A Design of experiments-method is used to quantify the effects of detergent components on the cleaning performance in mathematical models. The calculated models are used to adjust the amount of those components in a detergent formulation that increases the cleaning performance in low temperature electric household dishwashing. The modeled formulation has been verified in practical experiments.