Kenneth Aase Kristoffersen, Nofima AS
Bioprocessing of marine and agricultural by-products
There is an emerging industry built on enzymatic hydrolysis of marine and agricultural biomass. One of the frequently used enzymes are proteases, which breaks down the peptide chain in proteins by enzymatic catalysis at the expense of a water molecule. Examples of biomasses used in industrial valorization of protein-rich biomasses are fish and meat processing residues, and dairy industry by-products such as casein or whey. In industrial facilities, the proteolytic process takes place either in batch mode or through continuous processing. In either case, before the process start, one first adds water (50 – 67 %), where after the reaction is started by the addition of enzymes to the biomass/water mixture. The actual hydrolysis is usually allowed to proceed for one hour, normally at a temperature in between of 50 – 55⁰C.
In batch mode, the reaction mixture is stirred in the reaction vessel for the length of the hydrolysis. In continuous mode, the biomass are physically transferred from the point where the water was added and the reaction were started to an end-point during the reaction time interval. This movement can be done by several techniques. The reaction is stopped when the reaction mixture is heated to 90⁰C for approximately 15 minutes.
In this meeting we will give a small introduction to the world of valorization of protein-rich materials by enzymatic protein hydrolysis.