Value added fish by-products - Nordic Innovation

3.2 Ingredients from rest raw material of processing lines
The research on ingredients from rest raw materials of fillet production focused on four main
aims: Properties of the raw material from processing lines; properties of ingredients produced
from fillet production; application of ingredients produced from fillet production (injection
studies); and application of raw material and ingredients from fillet productions in consumer
products.
3.2.1 Properties of raw material from processing lines
Aim:
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Box 1
Analyse the effects of bleeding, processing, storage time, temperature and packaging on the properties of backbones and cut
offs produced during processing.
Increase the yield and value of catch processed on land, by finding ways to recover protein and tissues from the processing
water used during fish processing and evaluate their properties.
Outcome:
• Effect of bleeding, storage time and processing on properties of backbones and cut-offs (saithe).
� Protein denaturation of the frozen fractions showed fast loss in salt soluble protein in all fractions.
� Lipid oxidation was most pronounced in samples with blood/dark muscle/scraped backbones.
� No difference was found between backbones and cut-offs with regard to degree of hydrolysis for FPH
production.
• Effects of storage condition on lipid degradation in cut-offs and lipids from cod (Gadus morhua).
� Cut-offs should be kept at -24°C rather than -18°C as it reduces the influence of storage on their water
holding capacity.
� Cut-offs from saithe are more susceptible to lipid oxidation than cut-offs from cod and should be kept in
oxygen tight bags, i.e. vacuum bags, during storage.
• Recovery of material from processing water from skinning and filleting (cod)
� If the marine products contribute 60.000 ton pr. year, 1.200 tons will be lost in the processing water.
� The ratio of fish flesh lost during filleting of cod was 0.4% of the weight of gutted fish, 1.0% of the weight of
the fillets was lost during skinning.
� 25% of the total dried materials in the processing water from filleting were collected.
� By using vibrating sieve separator it was possible to collect fish flesh of good quality, in the filtration range
from 250 to 710 µm.
� The recovery cost of the material in the processing water does not overcome the benefit.
Challenges:
• Collection and preservation of raw material before transformation into protein ingredients
• In order to collect protein particles below 250 µm from the processing water different equipment should be
considered.