Effect of hydrocolloids on physicochemical,sensory and textural properties of reconstructed rice grain by extrusion cooking technology

Cracked or broken rice grains followed by lower rice efficiency during processing and milling of rice paddy are a major challenge contributing to the reduced economic productivity of this branch of industry. Therefore, the extrusion process for turning flour from broken rice or wastes into complete rice grains can bring about value-added for producers. In addition, an optimized formulation can improve product diversity and nutritional value. In this study, the effect of addition of Guar and Arabic gums on physicochemical, texture and sensory profiles of extruded rice grains was analyzed. Both gums were used in four concentrations (0.1, 0.2, 0.3 and 0.4 w/w %, d.b), and the effect of their different levels on properties of extruded rice was studied. Results from physicochemical tests on extruded rice samples showed that moisture content, water solubility index, water absorption index and bulk density were increased in samples containing higher concentration of Guar than Arabic gum and initial moisture content of 30% compared to no-gum samples, whereas lateral expansion, cooking loss, and total color change (ΔE) were reduced. Furthermore, results showed that higher levels of Guar than Arabic gum led to an improvement in sensory and textural properties.