Value added fish by-products - Nordic Innovation

protein loss can be reduced with rather coarse filters. With the equipment used in this project,
about 25% of all the dry matter from processing water from filleting was collected.
Figure 3.2. The quality of the collected fish mass with sieves (4-0.25 mm) from processing water from filleting.
The filtered mass had significantly lower dry material content than fish fillets processed at
the same time and as the filters became finer the dry material content was reduced (Table 3.4).
Collection of dry matter was the highest (61%) for the largest sieve (4 mm), relatively, but in
general it was between 10.2-16.2%. The filtered mass was not as white as the fillets, but as the
filter became finer the colour of the mass became more similar to the fillets as well as more
homogenous (Figure 3.2).
Table 3.4. Proportion and dry matter content of collected fish mass with regard to sieve size, along with relative
division of dry matter content in the collected fish mass with regard to sieve size. The fish mass was collected from
processing water from filleting.
Sieves size Proportion of collected fish Dry matter (%) of collected Relative division (%) 10
(mm)
mass (%)
27
fish mass
of dry matter
0.5 21.7 6.3 12.8
1.0 14.0 12.3 16.2
2.0 6.4 17.0 10.2
4.0 57.9 11.2 60.8
Total 100.0% 48.8% 100.0%
Protein composition of the fillets versus the filtered mass was not significantly different.
However, measurements on the time dependent flow behaviour viscosity of fish mass from
filleting and skinning (Brabender®) show a difference between the different fish masses. This
difference might be due to difference in collagens and phospholipids content. This could be a
subject for further investigation, i.e. using NMR technology to analyse the phospholipids from
the peptides.
10 Relative division (%) of dry matter content in the collected fish mass with regard to sieve size.