Effects of dry heat treatment on the structure and physicochemical properties of waxy potato starch

The effects of dry heat treatment (DHT) on the structure and physicochemical properties of waxy potato starch were investigated. The scanning electron microscopy, polarized light microscopy, X-ray diffraction, pasting properties, differential scanning calorimeter, swelling power, solubility and in-vitro digestion were evaluated. The surface and cross-polarized crosses structure of all starches had variation. The type of crystallite of waxy potato starch was changed from B to B + A after DHT and promoted a reduction in relative crystallinity. The pasting temperature was reduced through DHT, but the peak viscosity was enhanced. The rapidly digestible starch (RDS) content of starch increased and resistant starch (RS) content of starch decreased after DHT. •Dry heat treatment (DHT) can change the morphology of waxy potato starch.•DHT alters crystalline type of waxy potato starch from B-type to B + A-type.•DHT decreases ΔH and To of waxy potato starch.•DHT increases the peak viscosity of waxy potato starch.•DHT increases the RDS content and decreases the RS content of waxy potato starch.