Value added fish by-products - Nordic Innovation

and decreased water holding capacity (WHC) of the powders. Moderate time of hydrolysis
(15 to 45 min) yielded FPH with the best emulsifying properties.
Despite growing knowledge, there are still many challenges facing production and application
of FPHs. Among those are collection and preservation of raw material before hydrolysis and
optimisation of the hydrolysis process with regard to desired properties (taste and stability of
the powders during storage, content of bioactive peptides etc.). Before FPH can be marketed
on a wider scale, further standardization and documentation of the process and properties of
the FPH, both functional and health beneficial properties, is needed.
Production of mince is a common first step in processing of rest raw materials of fillet
production such as cut-offs and frames. Fresh mince has many applications but is in itself a
rather unstable product. It is therefore common practice to freeze it as quickly as possible.
However, freezing the mince reduces the water holding capacity which is an important
property when the mince is applied as an ingredient in fillet processing (injection). By
homogenizing the mince, its quality (including stability) as an ingredient could be improved.
Properties such as gel strength, gel forming ability and colour of FPI made from cut-offs are
significantly different from conventional Surimi and FPI made from fillets. Such FPI are
however still a good source of protein for manufacturing products which do not need high
level of gel strength, such as fish burgers, fish nuggets and other ready to eat fish products.
Addition of salt and sucrose improved the stability of the FPI. Further optimisation of the FPI
process is however needed for improved stability, texture, taste and flavour of FPI.
Extraction of gelatin from cold water fish species can take place at room temperature. As the
weight average molecular weight of gelatin increases, the dynamic storage modulus and
Bloom value increases. The Bloom values for gelatin from haddock, saithe, and cod were
determined to be 200, 150 and 100 g. By removing low molecular weight molecules from a
gelatin sample, the mechanical properties, i.e. the strength, of the resulting gel increased. Two
linear relationships between the mechanical properties and the molecular weight distributions
were established, one for cold water fish gelatin and one for mammalian gelatin.
The protein ingredients studied in this project (FPH, FPI, HFP and gelatin) have different
properties and thus are best suited to specific applications. Viscosity was higher in FPI than in
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