A project was recently completed here at IFL where it was investigated whether it is possible to use less detergent for routine cleaning of fish processing equipment, but with the same result. Reducing the concentration of detergents can mean financial efficiency for the fish processing companies and not least more environmentally friendly working methods.
To find out, a series of experiments were set up examining several aspects of the general cleaning process, which were: Type of surface (stainless steel and plastic), temperature of rinsing water (8 or 28 ° C), two types of detergent and concentration of detergent (2% and 4,5%).
To evaluate these factors, a newly installed washing station at IFL was used, which makes it possible to standardize the cleaning better than previously known. Bacteria from their natural environment (minced cod) were used to form bacterial coatings on steel and plastic surfaces. Bacterial counts were used to assess the effects of the factors in the washing process. The results showed that on a steel surface it is possible to use a lower concentration of detergents than recommended and still achieve comparable results (Figure 1). As can be seen, these washing processes manage to destroy all bacteria on the surface, regardless of the temperature of the rinsing water and the concentration of detergent.
However, in the case of plastic surfaces, the results were not as conclusive and it was generally more difficult to eradicate the bacteria.
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| Figure 1. Example of results after washing cycle on steel surface. |
Another aspect of this project was the analysis of the natural bacterial flora in the bacterial epithelium and a comparison of methods based on culture (Figure 2) and methods based on the amplification of the genetic material by molecular biological methods. Samples were taken from steel and plastic surfaces from the traditional washing processes of fish processing houses. Somewhat similar results were obtained with each method.
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| Figure 2. Bacterial flora grown on iron rods. |
The project was funded by the ACP and the Ministry of Fisheries.
A report has been published in the project called Better washing practices in fish processing plants (IFL report 26 - 06) Read
The aim is also to publish the results of the project in a peer-reviewed scientific journal.