The aim of this paper was to examine the influence and effect of high and low power ultrasound on rheological and thermophysical properties of potato starch. Suspensions containing ten percent of potato starch have been treated with ultrasound. All analysis have been carried out before and after power ultrasound treatment. Ultrasound bath of 22 kHz frequency and nominal power of 150 W has been used, as well as ultrasound probe of 24 kHz frequency and nominal power of 100, 300 and 400 W for 15 and 30 minute treatments. Rheological parameters have been determined with rheometer, whereas enthalpy, onset and end temperature of gelatinization with Differential scanning calorimetry (DSC). Micrographical pictures of ten percent suspensions of native and ultrasound treated potato starch showed changes in morphological structure of starch after ultrasound treatment. Rheological parameters showed that all suspensions exhibited non-newtonian (dilatant) character. Onset gelatinization temperature is higher for all model suspensions as compared to native starch. From the data one can observe obvious basic starch properties: retrogradation and gelatinization. It was determined that treatment with ultrasound of 400 W nominal power has the highest deterioration properties on starch granule.

Food processing technology