Ultrasound effect on physical properties of corn starch

Ultrasound irradiation in the production of ethanol from biomass

“…With increasing ultrasound power and intensity, the swelling power increases. The increase in swelling power of starches subjected to ultrasound irradiation is also higher for samples at higher temperatures [83].…”

“…However, due to the large volume involved in full scale processes, they recommended a continuous ultrasonic system in order to pretreat starch for its conversion to ethanol. Reduction in the particle sizes of starches subjected to ultrasound probes is also markedly more than that with ultrasound bath [83]. According to Khanal et al [62] the peak of particle size distribution curve shifted from 800 mm to around 80 mm following sonication at high power levels (475 W, 40 s) for cooked corn slurry samples.…”

“…Several studies have investigated the effects of ultrasound on the particle sizes of starches [62,77,78,83,85]. The hydrodynamic shear force introduced by ultrasound irradiation causes the disintegration of starch particles into a slurry into finer particles, significantly enhancing the surface area for enzyme activity [85a].…”

“…The extent of damage to starch granules suspensions is only slightly proportional to the ultrasonic intensity at the beginning, then increases markedly with the ultrasonic intensity after a power threshold is reached [26b]. Jambrak et al [83] observed that when applying more than the optimum ultrasonic intensity, starch granules tended to agglomerate becoming larger in shape and size, which is attributed to liberated bonds that offer the opportunity to connect linkages between polymers. However ultrasound with an optimal intensity can reduce the starch granule size and consequently change the physical/chemical properties of starch.…”

“…Some water present in the solution is also decomposed into OH and H radicals in the collapse of cavitation bubbles. Interestingly, in the process of cavitation, some of these radicals diffuse out of the bubbles to the surrounding liquid, and then react with molecules present into the solution causing polymer degradation [83]. The shear stress created by stable cavitation is considered effective if able to degrade high molecular weight polymers even without the presence of bubble collapse [101].…”