The granule morphology and its physicochemical properties of potato starch were studied after superfine grinding with a fluidized bed jet mill. The granule morphology

particle size and distribution

powder density and compressibility

pasting and thermal properties

solubility

swelling power and freeze-thaw stability were characterized using granularity analysis

scanning electron microscopy (SEM)

X-ray diffraction(XRD)

rapid viscosity analyzer (RVA) and differential scanning calorimetry (DSC). It was found that through the jet milling superfine grinding processing

the shape of potato starch granules changed from smooth polyhedron to rough

angles and cracks. The particle shape becomes irregular

the particle size decreases and the size distribution is uneven. Micronized powders prepared at 3000r·min

-1

had an average particle from 39.75 to 13.38

μ

m. The bulk density and tap density decreased with increased classifier frequency

and the compressibility of all the starch samples decreased. Jet milling did not change the crystal structure of the starch

but the crystallinity decreased. Jet milling reduces the attenuating viscosity and recovering viscosity of starch paste

the hot and cold paste stability of starch are better. And the gelatinization temperature

heat absorption enthalpy and freeze-thaw stability of starch are reduced

but the solubility and expansion degree of starch are improved. This study provided theoretical basis and technical support for improving the content and processing technology of potato starch

respectively.