Upgrading of maatjes herring byproducts: production of crude fish oil.
Fish oil has been extracted from byproducts of the maatjes (salted) herring production using a pilot plant consisting of a mincer, heat exchanger, and three-phase decanter. The crude herring oil obtained had an initial peroxide value (PV), anisidine value (AV) and free fatty acids (FFA) level of only 3 mequiv of peroxide/kg of lipid, 8.9, and 2.9%, respectively. 5,8,11,14,17-Eicosapentaenoic acid (EPA) and 4,7,10,13,16,19-docosahexaenoic acid (DHA) were present in considerable amounts (99 and 91 g/kg, respectively). During storage of the oil, no photooxidation could be detected. Storage at room temperature led to significant autoxidation over time, apparent from primary and tertiary oxidation products, measured by a decrease of hydroperoxides and an increase of fluorescent compounds (FC). Storage at 50 degrees C resulted in significant increases in secondary (AV) and tertiary oxidation (FC) products. At all storage conditions, the FFA contents remained low (<3%) and the alpha-tocopherol content remained constant. These results open the possibility for fish oil production of good quality using salted herring byproducts.
Aidos
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I
Netherlands Institute for Fisheries Research (RIVO), P.O. Box 68, 1970 AB IJmuiden, The Netherlands. isabel@rivo.wag-ur.nl
van der Padt
A
A
Boom
R M
RM
Luten
J B
JB
D000818:Animals; D004281:Docosahexaenoic Acids / Q000032:analysis*; D015118:Eicosapentaenoic Acid / Q000032:analysis*; D005395:Fish Oils / Q000737:chemistry* / Q000378:metabolism; D005399:Fishes; D005511:Food Handling / Q000379:methods*; D010084:Oxidation-Reduction; D013696:Temperature
D005395:Fish Oils; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid