Physically modified common buckwheat starch and their physicochemical and structural properties

Structural and physicochemical properties of physically modified buckwheat starches prepared using alcoholic-alkaline, drum-drying and ball-milling treatment were investigated and compared. The results showed that all of the treatments caused a significant increase in solubility and swelling power. SEM observations revealed that the starch granules obtained by different modified method exhibited a various morphological characteristics. X-ray diffraction showed that the crystallinity pattern of granular cold water soluble starch (GCWS) and micronized starch (MBS) changed from A-type to V-type, whereas pre-gelatinized starch (PGBS) granule exhibited a minor B-type pattern. DSC analysis showed that different treatments caused a significant lowering of the gelatinization enthalpy. RVA measurements revealed that the starch suspension viscosity of GCWS and MBS granules decreased compared to native starch, while PGBS granules exhibited an opposite trend. The present study will provide fundamental information of the GCWS, MBS and PGBS starch for their potential industrial application.