Texture and pasting properties of ultrasonically treated corn starch

Abstract

The effects of high power ultrasound of 24 kHz and ultrasound bath of 24 kHz frequency on the textural and pasting properties of corn starch suspensions was examined. Suspensions were treated with different intensities and treatment times (15 min and 30 min) using an ultrasound probe set and bath. The treatments with high power ultrasound probes caused a significant lowering of the starting gelatinisation temperatures of corn starch. The ultrasound treatment caused disruption of starch granules by cavitational forces and made the granules more permeable to water. The highest viscosity was observed for the treatment with 300 W probe. Also, a statistically significant increase in solubility in water (20°C) was observed, being caused by the disruption of starch granules and molecules by ultrasound treatment. When applying more powerful ultrasound, starch granules, specifically in the amorphous region, are much more mechanically damaged. The texture profile analyses of the starch gel prepared from the suspensions that had been treated with ultrasound probe presented higher hardness and higher values of adhesiveness and cohesiveness when compared with untreated suspensions or those treated with ultrasound bath. Micrography showed an obvious impact of ultrasound on the structure of starch granules. Ultrasound treatment ruptures and mechanically damages the starch granules causing collapse of cavitation bubbles which induces high pressure gradients and high local velocities of the liquid layers in their vicinity.

Comparison of Conventional and Ultrasound-assisted Extraction Techniques on Mass Fraction of Phenolic Compounds from Sage (Salvia officinalis L.)

“…5 Studying the extraction time (20,30, 40 min), it was observed that the mass fraction of the extracted phenols slightly Content of phenolic acids and flavone glycosides are expressed as mg per 100 g of dry sage; the sum of hydroxycinnamic acids (caffeic acid, salvianolic K and I acids, methyl rosmarinat); the sum of hydroxybenzoic acids (vanillic and syringic acids); Luteolin glycosides (6-hydroxyluteolin-7-glucoside, luteolin-7-glucuronide, luteolin-7-glucoside, luteolin-3-glucuronide); Apigenin glycosides (apigenin-7-glucuronide, apigenin-7-glucoside).…”

“…Generally, in a directly sonicated system, the energy of the probe unit is directly focused on a localized sample zone, thereby providing more efficient cavitation into the treated solution. [30][31][32] It is important to note that by using ultrasound, the extraction time was significantly shortened compared to conventional extraction. Based on the results from the first step of this research, optimal extraction conditions were defined for optimal extraction conditions for both extraction methods.…”

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

“…Each suspension was cooled to room temperature and centrifuged at 3000g for 15 min, and the supernatant was placed in a vacuum oven at 1058C for 4 h. The data obtained were used to calculate the solubility of the starch granules [16].…”

“…4. The solubility of native starch is 8.35%, and a significant increase can be observed in solubility which is caused by the disruption of starch granules and molecules through the ultrasonic treatment [20]. As the ultrasonic treatment time is increased, the solubility of starch increases.…”

Pre-treatment and extraction techniques for recovery of added value compounds from wastes throughout the agri-food chain

“…The sonotrodes are either directly immersed into the liquid (direct sonication) or attached to the bottom of the ultrasonic bath (indirect sonication). 380,381 Ultrasound-assisted extraction (UAE) is a technology based on the creation of cavitations that lead to tissue disruption. Disruption allows the diffusion of inner cell material without any significant increase in temperature, thus avoiding thermal degradation of the contained valuable compounds.…”