Morphometric, Physicochemical, Thermal, and Rheological Properties of Rice ( Oryza sativa L.) Cultivars Indica × Japonica

Abstract

The anther culture technical was applied to produce haploid lines of rice (Oryza sativa L.). The hybrids (K/ A92VM061, K/A92VM067, K/A92VM0611, K/A92VM719, K/A92VM720 and K/A92VM721) were obtained in order to generate new varieties from Indica and Japonica cultivars. Morphometric parameters of the grains were evaluated by image analysis. Flours were prepared from the whole rice grains and physicochemical, thermal and rheological properties, X-ray diffraction pattern and evaluation of color using the CIELAB system were assessed. The hybrids lines showed long (061, 611, 721), medium (719 and 720) and short (067) grains. The rice samples presented lipids (2.6% -3.2%), protein (11% -15%), total dietary fiber (8.4% -10.2%), total starch (65% -74%) and apparent amylose (5% -32%) contents. Gelatinization temperature (Tp) was found in the range of 66.1˚C -79.4˚C with enthalpy (ΔH) value between 3.4 -8.1 J/g. The retrogradation parameters (temperature and ΔH) were lower than those for gelatinization in all samples. The rice samples presented A-type X-ray diffraction pat-tern. Rice pastes showed a non-Newtonian behavior and the brightness (L *) characterize the color of the samples. Hybrid rice grains presented morphometric properties more similar to Japonica than Indica variety. Rice hybrid had higher protein content than Indica variety. Apparent amylose, viscosity and gelatinization temperature var-ied significantly among hybrids and varieties.