Physicochemical, morphological, thermal and pasting properties of a novel native starch obtained from annatto seeds

Abstract

This work presents physicochemical, morphological, thermal, and pasting properties of a novel native starch obtained from defatted and depigmented annatto seeds for applications in food-related areas. At the end of the annatto seed processing chain, a non-conventional white starch was obtained from defatted and totally depigmented seeds. After a comparison with a commercial corn starch, such novel product presented promising characteristics. The main attributes include a null content of pigment, an amylose content (24%) similar to corn starch, thin particles (D43 of 0.8 μm) of spherical-like shape, a typical crystalline A-type pattern with well-defined peaks at 2θ of 14.5°, 17.3°, 17.8° and 22.9°, thermal stability, and low mass loss (<10%) when heated up to 130 °C. The evaluation of pasting properties indicated a product with peak viscosity larger than corn starch, which is an important parameter for giving texture and body. Furthermore, the pasting temperature was 7.9 °C lower, enabling its use in preparations of sensible foods.