Abstract
When refined mackerel oil hydrogenated with a commercial nickel catalyst, the acid value increased considerably with hydrogenation temperature. Hydrogenation rate and trans isomer formation decreased above 235°C. With hydrogenated cod liver oils (mp 35°C, 39°C), steeper solid fat index (SFI) curves were obtained by selective hydrogenation with the nickel catalyst and hydrogenation with the palladium catalyst compared with normal or trans promotive hydrogenation with the nickel catalyst. Three fish oils, (cod liver oil, mackerel oil, and capelin oil) differing in fatty acid composition were selectively and trans promotively hydrogenated with the nickel catalyst up to mp 35°C. Hydrogenated oils with steeper SFI curves were obtained by the selective hydrogenation of cod liver and capelin oils containing less saturated acids or less polyenoic acids than mackerel oil.
