Novel cleaning process

An alternative process for the cleaning of equipment used for the production of powders has been developed within the scope of a joint research project. This process can be used to minimize the carry-over of allergenic food components.

The new regulation on food labeling for improved protection of the consumers against allergens in food also requires a new approach for the cleaning of machines and vessels. One aspect is the complete elimination of the possibility that allergenic components might be carried over to other product batches, e.g. in the production of bakery mixes or ready mixes for the baking and other industries. Usually this equipment was cleaned after product change-over without water, only governed by hygienic aspects (no water residues in the equipment), sensory quality and the compliance with amounts labeled.

To prevent the presence of free water in the equipment, a process up to now used in biotechnology has been adapted and further developed to meet these specific cleaning requirements. The process bases on a concentrated hydrocolloid solution (among others gelatin) which forms a film after application and can then be removed from the surfaces together with the adhering contaminants. Within the scope of the 30 month project, tests were conducted for optimization of the cleaning solution, its application and removal.

It showed that is was possible to adapt the spraying properties and the wetting behavior to the respective requirements. For example, with the addition of emulsifiers the binding of product residues, in particular fat-containing powders, could be optimized. The solutions for the formation of surface films were applied via two-substance nozzle and compressed air. After a short time, the films could be peel off without any problems. In a practical test of this alternative cleaning method with a plough blade mixer in the technical center at DIL it showed that the carry-over of contaminants can almost be completely prevented with this cleaning process.

Parallel to the development of this method, the project also dealt with methods for the detection of allergenic milk, egg and hazelnut compounds in different food products. Focus was placed on suitable extraction agents and conditions for the winning of the allergenic proteins. It was shown that the composition of the food product is sometimes significantly influencing the discriminatory power and the selectivity of the detection methods.

Within the scope of this research project, scientific and technical principles were developed that were needed for the adaptation and optimization of the new cleaning method to the conditions in the respective company. The DIL can provide equipment and expertise including know-how on allergen analysis in different food systems.

The project was supported within the scope of the “program for promoting joint industrial research (IGF)” by the Federal Ministry for Economy and Technology (via AiF) through the Association for Energy and Environment (VEU) (AiF project no 14805 N) and handled by the following three research organizations: