Sensory shelf life for protein products made from salmon backbones.

Abstract

The main goal of this project was to determine the sensory shelflife of proteins with neutral taste. Proteins were isolated from both the solid phase (sludge) from salmon oil production and from cooked salmon backbones. From both raw materials proteins were isolated after bone removal and subsequent removal of unwanted taste components by washing with warm water or warm water and ethanol. Effect of adding different antioxidants on the lipid oxidation in the protein products were studied. The best antioxidant were used in shelf life experiments where the lipid oxidation and sensory shelf-life of the products were studied. The best antioxidants for the isolated protein products were BHT, propyl gallate and alfa-tocopherols. Methal chelators like EDTA and citrate had no effect. A commersial mixture of tocopherols where used for the shelf life study. During the accelerated shelf life test (50'C and 570 hours) no lipid oxidation was detected, neither by Schaal test nor by sensory analysis. This holds for all teted proteins powders with and without antioxidants. The shelf life dependence on temperture was estimated by comparison of shelf at both 50' C and 70 'C through the use of the Arrhenius equation. This estimation indicates a shelf life of approximately 2 years at 20'C for the isolated salmon proteins. Two Norwegian companies have expressed interest in the results and wants to participate in developing this technology further towards industrial Production.