Title: Properties and utilisation of golden redfish (Sebastes marinus) head.
Abstract
This study characterises the chemical composition of golden redfish head with respect to size and explores the possibilities of new product development using a simple oil extraction process and other utilisations (minerals, collagen etc) of the red fish head. Respective yields of different head and carcass parts and their chemical composition are determined. Oil was extracted from the brain and eyes using the wet reduction method and composition evaluated. The gill had the highest (SH - 8.55 % and BH - 9.63 %) yield of all parts with the carcass constituting a larger (SH- 73.10 % and BH - 77.76 %) portion after other parts were separated. The brain had the highest lipid content (SH – 45.78 % and BH – 35.02) while the cheek had a high protein content (SH – 20.25 and BH – 18.25). The SH and BH brain had a lower free fatty acid while the SH eye and the BH eye had lower phospholipid. Profiles of fatty acid showed that the SH and BH gills are rich sources of polyunsaturated fatty acids eicosapentaenoic acid, docosahexaenoic acid n-3 fatty acids (about 26–32% of total fatty acids), and various minerals (Na, Ph, Ca, K, and Mg) with calcium being the most abundant micro element followed by phosphorus. Yield of SH brain oil extracted oil showed no significant difference with and without heat. BH samples showed a significant difference in oil extracted with and without heat. The SH oil samples had significant high free fatty acid content while no phospholipid was recorded in SH and BH oil samples. The fatty acid composition did not show significant difference between the mode of extraction. Results from this study show that redfish head contains large amounts of nutritional components and can be utilised to produce value-added products.