High-temperature hydrolysis as a method for complex processing of sprat (Sprattus sprattus balticus) by-products

Abstract

The aim of the study was to justify the com-plex processing of smoked sprat heads using the method of high temperature thermal hydrolysis. The new technology was tested with fatty (24%) and medium fatty (13%) raw materials using high temperatures in the range of 130-160 °С. As a result, the hydrolyzed organic mass was separated into fat, protein, mineralprotein and protein-fat emulsion fractions. Freeze-drying of the protein fraction and convective drying of the protein-mineral fraction resulted in food additives containing, respectively, low molecular weight water-soluble peptides and high molecular weight insoluble proteins and minerals. A rational method of hydrolysis is substantiated, including preliminary separation of fat in fatty raw materials and its enzymatic-thermal treatment. The optimal values of temperature and duration of hydrolysis in reactor are substantiated. Under these conditions, proteins are extracted most deeply from sprat raw materials, and the content of low molecular weight peptides in the protein freeze-dried hydrolysate powder is more than 80%. A comprehensive technology has been developed for the production of protein, fat and protein-mineral food additives from sprat processing by-products.