Study of the rheological characteristics of the potato-based fish and vegetable mixture melt in the pre-die zone of a single-screw extruder

Abstract This paper presents study of the rheological characteristics of the melt of the fish and vegetable mixture biopolymer in the pre-die zone of a single-screw extruder. The analysis of the flow index, being less than one, and that of the flow curves of the fish and vegetable mixture biopolymer melt, intended for production of expanded potato snacks, showed that the melt in a certain range of deformation rates can be attributed to pseudoplastic fluids. The results of the study represent important data in the design of the extruders molding units, on which the stability of the finished products quality depends. The results of the study can be used for mathematical modelling of the flow of the biopolymer melt in the pre-die zone of the extruder and can serve as justification of the screw rotational speed range in order to obtain extrusion foodstuffs of stably high quality.