EFFECT OF SUPERCRITICAL CO2, EXTRACTION OF OIL ON PHYSICOCHEMICAL PROPERTIES OF RESIDUAL ATLANTIC MACKEREL (SCOMBER-SCOMBRUS) PROTEINS

Protein residue of Atlantic mackerel, an underutilized fish species, w ar investigated following extraction of oil with supercritical CO2. Sp ring mackerel was extracted at 35-55C and 34.5-62.1 MPa for 5 h wherea s extraction time of 1-6 h was applied to fall mackerel at 35C/34.5 MP a. Water binding potential of fall mackerel proteins increased with ex traction time as oil was removed and that for spring mackerel reached a maximum of 2.2 g H2O/g protein at 55C and 62.1 MPa. Sarcoplasmic pro teins (SAR) became less soluble with increasing extraction temperature and pressure. This change occurred during the first hour of extractio n of fall mackerel. Analysis of the SAR by capillary electrophoresis s howed that proteins with a molecular weight of 50-100 kDa decreased, w hile MW > 100 kDa proteins increased with extraction pressure and time for spring and fall mackerel respectively, suggesting aggregation of proteins. Supercritical CO2 extraction of lipids from fish muscle show s potential for development of high quality functional proteins.