The main objectives of the PIPE project are to: (i) test technologies such as ceramic membranes and electrochemistry for their efficiency in separating organic matter from effluents from marinated herring production, (ii) characterize the chemical composition, antioxidant activity and functionality of different streams and fractions before and after separation and (iii) evaluate the market potential for the recovered fractions. Throughout the PIPE-project, effluent streams covering all steps in the marinated herring production i.e. from boat to the final marinated products, have been carefully characterized including different products type and over different seasons. Several pilot scale separation trials have also been carried out, and the fractions generated have been investigated for their basic composition, antioxidant activity and functional properties.
Method/implementation
Samplings of different streams were carried out on site at the herring producers and covered all steps from the boat to the barrel production. Careful chemical characterization was conducted (dry matter, proteins, amino acids, fatty acids and trace elements) together with antioxidant and enzyme activity analysis. The richest effluents were subjected to separation trials using electro flocculation and ceramic membranes, alone or combined. The results generally show that the technologies have to be further optimized to be able to perform a high efficiency separation of organic matter. With effluents from early steps of the process chain, the organic load could be reduced significantly; whilst for effluents generated later in the marinated herring production (herring maturation), this could not be achieved. Many of the effluents have a notable antioxidant activity, some enzymatic activity besides a high protein and fatty acids content Partitioning of key components into concentrates and outlets were followed. In some cases also emulsification and foaming properties were evaluated. Finally, a survey at the Nordic level was performed together with a cost benefit analysis in order to demonstrate the cost of implementation of new technology and the market value of collected fractions emerging from marinated herring production effluents. Thus, their potential market segment has been investigated.
Concrete results and conclusions
The herring industry is losing between 10% and 20% of the biomass in the water, an amount that is equivalent to several million Krone/year. Indeed, the effluents are heavy loaded with protein, non-protein nitrogen, fatty acids and trace elements e.g. iron and phosphor. The also present some very promising antioxidant capacity such as reducing power, radical scavenging and iron chelation, as well as enzymatic activity such as peroxidase and protease activity. Separation technologies were tested, however needs to be further optimized e.g. regarding flux or combined with other technologies in order to efficiently recapture the lost biomass for it potential commercialization to high-end products.
Recommendations
We strongly recommend further characterization and purification of seafood production effluents for identification of nutrients and potentially bioactive compounds for use e.g. in food, feed or as nutraceuticals. In some cases, expensive separation technology might not be necessary if effluents are treated as food grade and are used directly in food, however this need to be evaluated further.
Project owner
Caroline P. Baron
DTU - Technical University of Denmark, DK
Project leader
Caroline P. Baron
DTU - Technical University of Denmark, DK
Project members
Ingrid Undeland
Chalmers University of Technology, SE
Jesper Ditlev Freisleben
LiqTech, DK
Christian Kemp
A-factory, DK
Susanne Folmer
Lykkeberg A/S, DK
Christer Mattsson
Paul Mattsson AB, SE
Sigurd Fredriksen
Xylem, NO
Carsten Østerberg
Fisk og Fødevare Support, DK