Morphological, Structural, and Functional Evaluation of Rice Starch Acylated in a System Catalyzed by the B-Lipase of Candida antarctica

Starch modification by acylation induces significant changes in the mechanical and thermal properties of this polymer, widening the scope of its applicability to many different industries. In this work, the B-lipase of Candida antarctica is used as a catalyzer for the acylation of F60 variety rice starch, using linoleic and stearic acids as acyl donors in a homogeneous reaction system. Esterification is validated by infrared spectroscopy of the 1650–1750 cm⁻¹ band, attributes to the carbonyl group (C═O). Amylose and crystallinity analysis reveales a reduction in the amylose content and a direct correlation with the crystalline configuration of the polymer. The modification increases the solubility, water absorption, and swelling, which is attributed to the crystallinity loss. Following the modification, the granules increase in size and lose their hexagonal shape. These variations in the physicochemical, morphological, and functional properties may directly affect the production chain, enabling entrance to growing markets worldwide.