Physicochemical, Thermal, Crystallographic, and Morphological Properties of Biodynamic Black Rice Starch, and of Residual Fractions From Aqueous Extraction
Vivian C. Ito Egon Schnitzler Ivo Mottin Demiate Maria Ermelinda S. Eusébio Luiz Gustavo Lacerda Ricardo A. E. Castro
The physicochemical, thermal, crystallographic, and morphological properties of biodynamic black rice starch, and of the residual fractions from aqueous extraction, are evaluated. The contents of ash, dietary fibre, proteins, and lipids in the starch are lower than those from the residual fractions. The gelatinization temperatures and ΔHgel of the residual fractions differs significantly (p < 0.05) from those of the starch. All the samples had clear A‐type diffraction patterns, with main reflections at 2θ ≈ 15°, 17°, 18°, and 23°; they also presented a similar crystallinity index (≈22%). Bands in the infrared spectra assigned to proteins and to carbohydrates (starch) are clearly identified, and the structural indicator (I1046/I1018) of the degree of double helical order is calculated. Micro‐images shows polyhedral starch granules having irregular shapes, with sharp angles and edges, and without pores on the smooth surface.