Value added fish by-products - Nordic Innovation

2 Background
Seafood processing discards and rest raw materials account for approximately three-quarter of
the total weight of the catch (Shahidi 1994; Pastoriza et al. 2004). Fish processing rest raw
materials are usually regarded as residuals left after filleting and when viscera is included this
can represent up to 2/3 of the round cod (Mackie 1974; Slizyte et al. 2005b; Falch et al.
2006a; Falch et al. 2006b). Valuable components such as fish oil, proteins, collagen and
gelatin, enzymes and minerals can be obtained from this raw material. Recent studies have
identified a number of bioactive compounds from fish rest raw materials and shellfish and
crustacean shells (Kim & Mendis 2006). These compounds can be extracted and purified with
technologies of varying complexity. Development of new technologies to extract new
bioactive compounds from marine processing rest raw materials may bring more value from
what is today considered a waste.
Figure 2.1. Products and rest raw materials from shore processing of cod.
Proteins or other macromolecules are often added to a food to improve their quality or
functional properties. One much used definition of functional properties is: “Those physical
and chemical properties that influence the behaviour of proteins in food systems during
processing, storage, cooking and consumption” (Kinsella 1979). A description of the
properties of the proteins important for functional properties was given by Damodaran 1997:
“The physico-chemical properties that influence functional behaviour of proteins in food
include their size, shape, amino acid composition and sequence, net charge, distribution,
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