RHEOLOGICAL CHARACTERIZATION AND MODELING OF RICE FLOUR DOUGH: EFFECT OF PARBOILING TIME, MOISTURE CONTENT AND GUM ARABIC

Abstract

ABSTRACTSmall‐deformation compression and stress relaxation studies in addition to nonoral sensory assessments were performed on rice flour doughs, obtained by parboiling at different times (0–60 min), moisture (48–60%) and gum Arabic contents (0–0.5%). The response functions were the rheological (firmness and compression energy, initial and equilibrium moduli and relaxation time) and nonoral sensory attributes (ease of extrusion, cohesiveness and stickiness) of dough. Compression energy increased with parboiling time but decreased with moisture content. Relaxation time varied from 0.15 to 20.2 s, meaning a wide variation in the behavior of dough is possible to achieve. The viscoamylographic studies indicated that parboiled rice pastes exhibited more stable status toward retrogradation and showed lesser shear‐thinning phenomenon compared with their counterpart raw rice samples. The stress decay curves could be modeled by three‐element spring‐dashpot Maxwell–Voigt model (r ≥ 0.81, P ≤ 0.01). The optimum condition for obtaining a dough with minimum stickiness and maximum ease of extrusion was computed.PRACTICAL APPLICATIONSRice is extensively used in various forms of food as whole grain as much as flour. Because of nonglutinous properties, rice dough from raw flour cannot be easily flattened or shaped, whereas thermal treatment like parboiling and the use of gum Arabic can make the dough suitable for formulating different products. The addition of gum during dough preparation can retain more water and modify its rheological properties, improving the dough handling characteristics and textural attributes of the finished products. The specific applications of reported findings lie in the development of rice‐based products such as ready‐to‐eat and ready‐to‐fry/bake snacks, baby foods and breakfast cereals.