The aim of this paper was to evaluate the effect of thermal treatment and UV irradiation on structural and physicochemical properties of octenyl succinate (OS) maize starches differing in content of OS groups (0.76%-2.38%). X-ray diffraction (XRD), gel permeation chromatography (GPC), and electron paramagnetic resonance (EPR) spectroscopy were used to estimate structural characteristics of octenyl succinate starches and their physically treated counterparts. Starch functional properties were also determined. XRD spectra and hydrodynamic volume distribution revealed that growth of octenyl succinate groups' content resulted in stabilization of starch structure, which was confirmed by processes of radical formation, stimulated by thermal and UV treatments. It was found, on the basis of measurements of water binding capacity, water solubility and intrinsic viscosity, that OSA addition changed physicochemical properties of starch and influenced the course of physical modifications. It was established that temperature affected starch properties to a greater extent than UV.
Keywords: Carbohydrate radicals; EPR; Functional properties; GPC; Octenyl succinate starch; Starch structure; XRD.
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