Rainbow trout (Salmo irideus) produced in Finland VII. Changes in the organoleptic quality and fetty acid composition during frozen storage

Abstract

Rainbow trouts were frozen at –40° C and stored either glazed with water or vacuum packed in polyethylene bags at –18°and –32° C. During the storage time the quality of the fish was tested both organoleptically and by determining the fatty acid composition of the lipids. It was found that the fish were organoleptically uneatable after three months of storage. At –32° C the fish kept their organoleptic quality somewhat better than at –18° C. There were no important differences between the two packing systems used. The fatty acid analyses gave comparable results in all instances and probably changes in the proteins during frozen storage are more significant than changes in the lipids and are mostly responsible for the lowering in quality of frozen rainbow trout.