Effect of high-intensity ultrasound treatment on nutritional, rheological and structural properties of starches obtained from different cereals

Abstract

The ultrasonication was applied to four cereal starches namely wheat, barley, rice, and maize for two ultrasonication treatment durations, i.e., 15 and 30 min (T 15 and T 30, respectively) and were evaluated for their in vitro digestibility, XRD, FTIR spectroscopy, morphological and rheological properties. Ultrasonication increased the swelling power and solubility of starches from different cereals. For ultrasonicated starches (both raw and cooked), the RDS and RS content exhibited significant (P ≤ 0.05) an increase with an increase in treatment duration. RDS content exhibited an increase after both cooking and ultrasonication and ranged between 67.8 and 81.4%, whereas RS content declined with cooking and enhanced with ultrasonication and ranged between 2.3 and 3.1% after T 30 while SDS content decreased with increase in ultrasonication duration. FTIR spectra of ultrasonicated starches showed the characteristic broad peaks at 3351 to 3404 cm−1and to assigned to OH stretching of the hydroxyl group. The rheological properties showed an increase in G′ and G″ for 15 min ultrasonication and decreased with 30 min ultrasonication. The main effects of ultrasonication were led to the formation of depressions and pores on the surface of starch granules, which were appropriately observed in wheat and maize starches.