Alternative surface systems and biomonitoring
The aim of this project is the reduction cleaning/service time, the extension of maintenance intervals and the enhancement of processing safety during machining of foodstuff by using anti adhesion surfaces. The work is focused on apertured surfaces and outside surfaces from food processing machines.
To estimate the potential of application it is necessary to evaluate the properties with commercial available and pre-release anti adhesion surfaces regarding the propensity for defilement and the cleanability.
Therefore different surface are used for lab cleaning tests by using stainless steel as a reference.
The cleaning test is organized in three steps:
1. Defilement
2. Cleaning
3. Determination of remaining dirt.
From relevant product categories like proteins, starch and fats representatives like ß-lactoglobuline (part of whey proteins), starch from potatoes and cocoa butter have been used as defilement agents. Furthermore the adhesion of micro organism onto different surfaces is to be investigated. Therefore Pseudomonas fluorescens, Lactobacillus brevis, Bacillus subtilis (spores) and Saccheromyces cerevisiae were selected.
For the simulation of industrial cleaning processes of apertured surfaces a high pressure sputtering (3-20 bar)was used. As cleaning agent water, sodium hydroxide solution and nitric acid were used.
At the beginning of this project the remaining contamination was determined gravimetrically but later more sensitve methods were etablished like the detection of of ß-lactoglobuline via immune fluorescence where the defilement agent was detected with a fluorescent labeled antibody via fluorescence microscopy. Starch was detected by iodine solution, fats were detected by using lipophilic dyes like acridine orange. The detection of micro organisms was done by fluorescence microscopy. The project aims to detect the contamination direct onto surfaces by quantification with automated image analysis. Beside surface properties with respect to cleanability investigations of adhesion properties, abrasion and scratch resistance, Vickers hardness, wettability and impact strength were done. In further cooperations with project members application possibilities for anti adhesion surfaces for foodstuff processing machines were investigated. Selective units has been modified. Within a „Proof of concept“ a comparison between conventional and modified surfaces regarding the expense of cleaning was done with a statement about the potential of cost reduction.
Cooperation partners:
Frauenhofer AVV
Financing:
AiF by IVLV
Contact:
Eschenhagen, Bley