Submitted to: Journal of Food Processing and Preservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/13/2009
Publication Date: 8/20/2011
Citation: Oliveira, A., Bechtel, P.J., Lapis, T., Brenner, K., Ellingson, R. 2011. Chemical composition of black rockfish (Sebastes melanops) fillets and byproducts. Journal of Food Processing and Preservation. 35(4):466-473. Interpretive Summary: Rockfishes are a diverse group of marine fishes. Yearly catches of all rockfish amount to approximately 50,000 T and are worth about 11 million dollars in the US federal fishery. Black rockfish, also known as black snapper or black bass are found along the west coast of the US from Alaska to California. Little information exists about the quality and the chemical composition of black rockfish as food. Byproduct volume consists primarily of viscera and heads, which comprise up to 52% of the whole fish weight. The composition of black rockfish by-products, which could potentially be further processed into food and feed ingredients, as well as the fillets has not been reported. The objective of this research was to characterize nutritional parameters of black rockfish fillets, heads and livers from fish commercially harvested from Alaska waters. Results of this study indicated that head and liver black rockfish by-products can be utilized for the production of good quality specialty ingredients to be used as food and feed components. This research is part of an ongoing effort to promote full utilization of Alaska fisheries resources by determining the nutritional value of fish processing by-products.
Technical Abstract: Black rockfish are important in the near shore fishery of Southeast Alaska. They are the only species among the pelagic shelf rockfishes for which there is a directed fishery in state waters. The purpose of this study was to determine the composition black rockfish fillets and its major processing byproducts. Fillet yields for black rockfish were relatively low at about 13.7% of whole fish weight (WFW), while heads make up 24.8% of WFW. Black rockfish livers made up only 1.9% of WFW; however, livers were a valuable source of lipids (~20%). In contrast, black rockfish heads had about 7.4% lipids. Marine oils extracted from the tissues investigated were similar in many aspects to oils from other cold water marine finfish, being rich in omega-3 and omega-9 fatty acids, and low in omega-6 fatty acids. Protein content of fillets, heads and livers were within the expected ranged from 15% to 20% Amino acid analysis revealed that the protein was of very high quality. Results indicated that head and liver black rockfish by-products can be utilized for the production of good quality specialty ingredients to be used as food and feed components.