Effects of ultrasound on the extraction of antioxidants from bearberry (Arctostaphylos adans) leaves

Abstract

The effects of ultrasound (f = 60 kHz) on the quantity of biologically active substances extracted from bearberry leaves into a water:ethanol (1:1) mixture were studied, along with their antioxidant properties. The optimal conditions for extract preparation were identified: the raw material:extractant ratio and the duration of ultrasound exposure. Positive and negative aspects of the ultrasound extraction of antioxidants are discussed. The antioxidant activity of the extract prepared in optimum conditions was greater than that of a bearberry leaf extract prepared without ultrasound, increasing the resistance of sunflower oil to oxidation by factors of 2 -2.2. 593 0091-150X/08/4210-0593

Study of continuous flow ultrasonication to improve total phenolic content and antioxidant activity in sorghum flour and its comparison with batch ultrasonication

“…Even though maximum AA was obtained at low FWR and UI for both the ultrasonication processes, continuous flow exhibited comparatively 7% more AA in the sorghum flour at 33% less UI. Similar results were found by Gribova et al [50] for AA of bearberry leaves. Tabaraki and Nateghi [44] also reported no significant change in scavenging activity of DPPH of rice bran at higher liquid to solid ratio.…”

Effect of sequential treatments of fermentation and ultrasonication followed by extrusion on bioactive content of apple pomace and textural, functional properties of its extrudates

“…1). Similar results were found by Gribova et al (2008) for AA of bearberry leaves. With an increase in PWR, increased concentration and viscosity of the sample might hinder ultrasound waves to travel uniformly in the whole sample at a given UI.…”

Influence of fermentation followed by ultrasonication on functional properties of sorghum extrudates

“…Further increment in flour to water ratio did not show any significant ( p > .05) decrement in TPC, but a significant ( p < .05) diminution was observed in AA of the sorghum flour. These results were in accordance with the findings of Gribova, Filippenko, Nikolaevskii, Khizhan, and Bobyleva () for AA of bearberry leaves. Due to higher viscosity of solution, with an increase in the flour to water ratio at a given UI, ultrasound energy could not transmit uniformly in the sample solution and thus resulted in limited extraction of phenolics.…”