Proteolytic processing of herring (Clupea harengus): biochemical and nutritional characterisation of hydrolysates

P>Food research on fish has demonstrated that they constitute excellent nutritional components. The aim of the present work, was to process herring (Clupea harengus) using Protamex (R) and evaluate the distribution of nutrients in various fractions obtained following membrane filtration. The fish starting material was composed of approximately 88% water and the dry matter contained 59% crude proteins, 33% lipids and 5% minerals. The recovery of fish dry matter in the liquid hydrolysate was 67.8%. Most protein enriched fractions demonstrate a well-balanced amino acid composition, notably the most essential amino acids. These protein fractions are characterised by biomolecules having a relatively low molecular weight (45 kDa and less) range. Even though the process could be optimised, the biochemical and nutritional analyses indicate that the herring may serve as high-value products for future applications in the health and food sectors.