Fish protein hydrolysates based on Atlantic salmon by-products. Enzyme cost-efficiency and characterization of sensory, surface-active and nutritional properties

• Published in: Process Biochemistry
• Main Author: Aspevik, Tone
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: The University of Bergen 2016
• Subjects: Atlanterhavslaks; Fiskemel; Proteiner; Norge; Fiskeforedling; Norway; Atlantic salmon; Salmo salar
• Online Access: https://hdl.handle.net/1956/12181

The world fisheries and fish farming industries generate large amounts of by-products after the primary processing of fish to edible products. In Norway alone, this accounted for almost 900,000 tons in 2014. Based on present industrial practice, most of the by- products are either discarded or used in the manufacture of low-value commodity products such as fish silage, fishmeal and oil. By-product material from the primary filleting process, such as heads and backbones, contain high-quality food grade proteins with a great potential for value creation. The production of water-soluble protein hydrolysates using exogenous proteases may give an increased valorization of the by- products for human consumption and offers a mild and efficient processing approach without prejudicing the nutritional value. Proteases act by cleaving proteins into smaller peptides and free amino acids that are more water-soluble and have altered sensory and surface-active properties compared to the intact protein. A major drawback in the production of commercial fish protein hydrolysates (FPHs) is the formation of bitter and unpalatable tastes due to exposure of hydrophobic amino acids and moieties during the hydrolysis process. Moreover, the cost of enzymes and high processing expenses may be a hindrance in a profitable production of FPHs for human consumption. This has led to a demand for new and improved knowledge of cost-efficiency of enzymes and the process conditions that influences the formation and reduction of bitter taste. Reduction of the bitter taste is of utmost importance in the production of FPHs, but also knowledge of the surface-active and nutritional properties of a hydrolysate may be important for its potential inclusion in food products. The main objective of this study has been to produce FPHs based on Atlantic salmon (Salmo salar) head and backbone products with low bitter taste, good surface-active properties and high nutritional value. The hydrolytic and cost efficiency of five commercial endopeptidases (Alcalase ...