Extrusion parameters and physical transformations of an extrudate for fish: Effect of the addition of hydrolyzed protein flour from by-products of Oncorhynchus mykiss

Introduction The food industries play a fundamental role in feeding for the functions of animal metabolism. Fish feed extrusion cooking includes process-independent factors such as temperature (°C), screw speed (RPM), throughput, feed, and moisture content that influence final product's nutritional value physical properties. evidence suggests application hydrolyzed protein flour (HPH) is crucial step techno-functional properties product. Therefore, this work aimed to study effect meal from silage trout ( Oncorhynchus mykiss ) on parameters system their transformations. Methods In study, meals ranges between 10 30% substitute fish meals. extrudate were monitored, evaluating hardness, durability, buoyancy, expansion index, apparent density. Results Consistent with this, composition, speed, content, process affected composition Discussion indicated presented cohesiveness decreased mean retention time extruder barrel specific mechanical energy (SME). Hydrolyzed during produces pellets high durability low hardness due porosity presented, which allows obtaining characteristics extruded