Biotechnology
Quality aspects in the production
of omega-3 products from fish oil
Sverre Sondbo, Frode Flem, Hjalmar Olav Saav,
Heidi Eskedal Pedersen, Olav Thorstad
Pronova Biocare, PO Box 2109, 3202 Sandefjord, Norway
It is well established that the polyunsaturated omega-3 fatty acids EPA
and DHA are vulnerable to chemical reactions. The most well-known
of these are oxidation reactions in presence of oxygen, where the oxidation products responsible for the rancid taste and smell of fish oils
are created. Reactions may also occur in absence of oxygen. The reason
why polyunsaturated fatty acids quite easily undergo such reactions is
that the normal arrangement of double bonds in all polyunsaturated
fatty acids is quite unstable. Multiple double bonds separated by one
methylene group are a more unstable arrangement than conjugated
double bonds, ancl trans-double boncls are more stable than cis.
Both conjugation and transification will therefore be an energetically
favourable process for polyunsaturated fatty acids. Conditions that may
bring about such rearrangement reactions could be elevated temperatures, as during deodorization, or an alkaline environment as during
hydrolysis or esterification processes.
We have stuclied the occurrence of diherent reaction products as a result
of different process steps, with special emphasis on heat treatment
during deodorization. It will be concluded that when oxygen and basic
substances are absent the omega-3 fatty acids are relatively stable to heat,
and that the standard processes used for deoclorization do not harm the
oils to any particular degree.
225
Quality aspects in the production
of omega-3 products from fish oil
Sverre Sondbo, Frode Flem, Hjalmar Olav Saav,
Heidi Eskedal Pedersen, Olav Thorstad
Pronova Biocare, PO Box 2109, 3202 Sandefjord, Norway
It is well established that the polyunsaturated omega-3 fatty acids EPA
and DHA are vulnerable to chemical reactions. The most well-known
of these are oxidation reactions in presence of oxygen, where the oxidation products responsible for the rancid taste and smell of fish oils
are created. Reactions may also occur in absence of oxygen. The reason
why polyunsaturated fatty acids quite easily undergo such reactions is
that the normal arrangement of double bonds in all polyunsaturated
fatty acids is quite unstable. Multiple double bonds separated by one
methylene group are a more unstable arrangement than conjugated
double bonds, ancl trans-double boncls are more stable than cis.
Both conjugation and transification will therefore be an energetically
favourable process for polyunsaturated fatty acids. Conditions that may
bring about such rearrangement reactions could be elevated temperatures, as during deodorization, or an alkaline environment as during
hydrolysis or esterification processes.
We have stuclied the occurrence of diherent reaction products as a result
of different process steps, with special emphasis on heat treatment
during deodorization. It will be concluded that when oxygen and basic
substances are absent the omega-3 fatty acids are relatively stable to heat,
and that the standard processes used for deoclorization do not harm the
oils to any particular degree.
225