Physicochemical, technological and sensory characteristics of a rice (Oryza sativaL.) and bean (Phaseolus vulgarisL.) soup prepared by extrusion

Abstract

SummaryThe aim of this work was to prepare and evaluate an instant soup formulated with broken rice and beans processed by thermoplastic extrusion using a pilot‐scale, single‐screw extruder. The final product was characterised regarding its physicochemical composition, amino acid profile, functional–technological properties and sensory performance. The extrusion parameters were set using three extrusion zone temperatures (30, 40 and 70 °C), a screw speed of 177 rpm, feed rate of 260 g min−1. and circular matrix of 3.85 mm. The final product contained considerable levels of protein (12.91 g per 100 g) and dietary fibre (8.07 g per 100 g). Amino acid profile analysis showed that only sulphur‐containing amino acids and tryptophan were limiting with the remaining present in adequate concentrations to meet children's requirements. Regarding functional and technological properties, the instant soup powder showed appropriate water solubility and water absorption indexes as expected. The soup sensory analysis indicated good acceptability, with a purchase intent index of 71%.