What was the goal of the project?

The project focused on using enzymes to produce collagen from split cowhide. The standard process used to produce collagen involves chemically treating split cowhide followed by mechanical mincing. The resulting collagen mass can then be used to make sausage casings and stuffing tubes. We integrated an enzymatic treatment step into this process chain, thereby successfully establishing a procedure to more specifically process collagen that results in enzymatically modified collagen. Sausage casings made from this type of collagen are very thin, tear-resistant when filled, and have very good sensory characteristics. 

Was it difficult to transfer your research findings to the pilot scale?

Not at all. The project also specifically focused on making sure that this was possible. We developed a new technical scale concept for the use of enzymes at a company called N-Zyme BioTec GmbH and subsequently transferred the concept to Naturin Viscofan GmbH. The first test extrusions on the pilot scale were then carried out.

What is the advantage of using enzymes?

The use of enzymes enabled us to produce for the first time a collagen mass that was suitable for producing sausage casing prototypes that were thinner than normal, but had the same or even superior application properties. We found out that a certain “degree of comminution”, i.e. the defined distribution of collagen fibre thickness and quantity, was necessary in order to be able to extrude casings and membranes with desired product properties. The degree of disintegration depends to a large extent on the preceding enzymatic step. In addition, the enzymatic procedure is able to replace a few chemical treatment steps. We carried out a profitability assessment that measured the costs of enzyme against the quantity and costs of chemicals and the water management process, and found that chemical quantities and water usage costs were reduced through the use of enzymes.

Where else can the thin collagen membranes be used?

Membranes made from enzymatically modified collagen could be used in the fields of cosmetics, biotechnology and biomedicine, i.e. sectors other than the food industry. In such cases, a process combining pure enzymatic treatments with a more energy-intensive comminution procedure could be developed, leading to a collagen mass that could be used to make even thinner membranes.

What do you think has made the project so successful?

The know-how of the partners involved complemented each other very well. An important success factor was the provision of suitable (commercial) enzymes by N-Zyme BioTec GmbH and ASA Spezialenzyme GmbH. N-Zyme BioTec GmbH analysed the enzymatic processes to ensure that the enzyme, in our case a protease, was not inactivated under the normal conditions, i.e. pH value and ionic strength, of collagen mass production. This led to the development and integration of a specific enzymatic treatment step into the original process, so that no investment was required for developing a completely new process. The availability and use of commercial enzyme preparations that are authorised for use in human food and which produce the desired results in economically viable amounts enable the direct implementation of the process.

How did the analytical and process-related innovations affect the development of the prototype?

These innovations were a prerequisite for the successful development of the prototype. We worked with the Mannheim University of Applied Sciences to develop robust analysis methods that can be applied to product development processes. These methods can be used to determine the size of the collagen fibres and intermediary collagen products. They are also necessary for assessing collagen mass in terms of production and application; they are important tools for determining how successful mincing collagen rinds into collagen masses in the processes under investigation would be. This then means that the technological and financial aspects related to the use of enzymes for producing collagen sausage casings can also be evaluated.

What about the potential if you were to optimise the application for other proteins and carry out further research?

The findings are useful for developing soluble and dispersible collagen-based proteins with novel functional properties. New products with improved water-binding properties and optimised properties in terms of adhesion, film- and gel formation would then be available. The products could be used in the meat- and fish-processing industries. Products like surimi come to mind. Another interesting application might be the packaging industry. Enzymatically modified collagen could be used to produce biologically degradable labels, packaging and adhesive tapes. On behalf of Naturin Viscofan GmbH, I would like to thank all the project partners: ASA Spezialenzyme GmbH, Bio-Logik-Control, Mannheim University of Applied Sciences and N-Zyme BioTec GmbH.