Common Buckwheat-resistant Starch As a Suitable Raw Material for Food Production: A Structural and Physicochemical Investigation

Heat-moisture treatment (HMT) of starch is defined as a physical method to change its properties. Compared with maize and potato, starches from common buckwheat (Xinong9976 and Pingqiao2) were isolated and its morphology and physicochemical properties investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), ATR-FTIR analysis, rapid viscosity analyzer (RVA) and differential scanning calorimeter (DSC) were studied before and after HMT. The experimental results showed that there were obvious differences between native starch (NS) and resistant starch (RS) of common buckwheat. HMT altered the A-type crystalline pattern and the degree of short-range order of common buckwheat starches and significantly decreased water solubility, swelling power (70-90 °C), freeze-thaw stability and pasting properties and increased oil and water absorption capacities, light transmittance as well as thermal stability. This study shows that the NS and RS of common buckwheat can be used as the suitable raw materials in food processing.