Effect of Ultrasonic Treatment on the Physicochemical Properties of Maize Starches Differing in Amylose Content

Abstract

Normal maize, waxy maize and amylomaize V starches were treated at a moisture content of 70% by ultrasonic treatment. The results showed that the surface of normal and waxy maize starches was porous after treatment and a fissure could be clearly observed in the surface of amylomaize V starch. Ultrasonic treatment did not change the X-ray pattern of the three maize starches. The swelling power (amylomaize V (B-type) . normal maize . waxy maize (A-type)) and solubility (amylomaize V . normal maize . waxy maize), the syneresis of amylomaize V starch and the gelatinization transition temperatures of the three starches increased on this treatment. Ultrasonic treatment decreased the syneresis of normal and waxy maize starches, the enthalpy of gelatinization (amylomaize V . waxy maize < normal maize) and the gelatinization temperature range (amylomaize V . normal maize < waxy maize) of all starches. A drop in viscosity of all three starches was observed and the viscosity patterns of three starches remained unchanged after ultrasonic treatment. The data showed that ultrasonic treatment degraded preferentially the amorphous regions and more easily attacked linear amylose than highly branched amylopectin.

Selected Applications of Ultrasonics in Food Processing

“…The amylose located in the growth rings was reported to be degraded due to sonication whereas the amylopectin appeared less affected. Similar results have also been reported for native maize, waxy maize and amylomaize starches by Luo et al [44]. The increase in formation of holes on the granules has been proposed by the authors [34,44] to increase the rate of penetration of reagents into the bulk of the starch granule which could increase the chemical reaction rate.…”

Dual‐frequency ultrasound effect on structure and properties of sweet potato starch

“…The onset temperature reflects the first measurable swelling of the starch granules as reflected by the appearance of an increasing viscosity, and the gelatinization temperature reflects the beginning of the granule distortion or disruption after the granular structure can no longer support the continuing swelling. The peak viscosity of the native starch is 447.0 BU, and the ultrasonic treatment caused a significant lowering of the viscosity [19]. The peak viscosities of starch treated by 25 and 80 kHz ultrasound are 6.94 and 9.84% lower than the native starch, respectively, however, the lowest viscosity, which is 14.09% lower than the native starch, can be observed with the starch treated by dualfrequency ultrasound.…”

Physicochemical properties, modifications and applications of starches from different botanical sources

“…Ultrasound primarily affects the amorphous region, while maintaining the granule's shape and size. The starch surface becomes porous, and properties such as the swelling capacity, solubility and viscosity of the paste are modified (Luo et al, 2008). Ultrasonic modification depends on the sound, frequency, temperature, process time and the starch suspension properties (i.e., concentration and botanical source of starch) (Zuo et al, 2009).…”