Ultrasound-assisted acid-thinning of corn starch: Morphological, physicochemical, and rheological properties

In the present work, different rheological and physicochemical properties of normal corn starch as affected by different parameters of ultrasound and its simultaneous coupling with acid hydrolysis were studied. The results revealed that sonication and its combination with acid hydrolysis increased solubility of starch granules without destructing crystalline structure, while maximum complex viscosity, breakdown, and activation energy of gelatinisation decreased. Flow behaviour of samples sonicated in acidic solutions experienced a distinct transition from pseudoplastic to Newtonian behaviour. In addition, the gel elasticity, time-dependency, and structural recovery of samples were diminished. The results of present study would be of great value since ultrasound facilitated production of granular acid-thinned starch in less than an hour without using any additional chemicals.