Synergistic effect of ozone treatment with α-amylase on the modification of microstructure and paste properties of japonica rice starch.

The objective was to evaluate the synergistic effect of ozonization and α-amylase on modifying the microstructure and paste properties of starch, using 0.00042 g of ozone/100 g of buffer for various durations. Enzymatic susceptibility was increased, achieving maximum values of 12.73 % with an 11.42 % increase in crystallinity and an average particle size of 10.12 μm for 90 min treated japonica rice starch (JR90). The granules exhibited a polyhedral shape and, with increased intensity of combined treatments, formed clusters and lost their original geometry. Apparent viscosity, rheological, and textural parameters were reduced due to the more efficient action of α-amylase on ozonized starch, as confirmed by the low gelatinization enthalpy value (7.61 J/g). Ozone proved effective in opening starch chains, partially gelatinizing granules, homogenizing the enzymatic medium, and increasing the hydrolysis rate of α-amylase in japonica rice starch. [Display omitted] • The synergy of ozonation and α-amylase increases digestibility to 12.73 %. • Ozonation for 90 min increases starch crystallinity by 11.42 % with granules of 10.12 μm. • Prolonged ozonation causes starch granules to lose shape and form agglomerates. • Combined treatment lowers viscosity, with gelatinization enthalpy of 7.61 J/g. • Ozone breaks starch chains, partially gelatinizing granules, improving hydrolysis. [ABSTRACT FROM AUTHOR]