Lavinia Tătaru, Catalin Ducu, Denis Negrea, Sorin Moga
Full Text PDF | antioxidant activity, Aronia melanocarpa, silver nanoparticles
Two hydro-alcoholic extracts of Aronia melanocarpa berries were obtained by different extraction techniques: classical solvent extraction by maceration with solvent, under stirring, for 10 hours and ultrasonic assisted extraction at 20 kHz for 5 minutes, respectively. In both cases the ratio dried vegetal material: hydro-alcoholic solvent mixture (3:1, v: v) was 1: 10 (g: g). The resulting extracts were analysed to evaluate their antioxidant capacity. An important antioxidant activity expressed by the amount of total polyphenols content and antiradical power it was shown for both extracts. The method using ultrasounds was more efficient leading to extracts richer in polyphenols (5376.947 mg GAE/10. 0g D.W.) and with higher antiradical power meaning higher percentage of inhibition of DPPH and lower EC50. Using this powerful extract, the synthesis of some silver nanoparticles was performed, and the results were confirmed by molecular absorption spectrometry (MAS) and scanning electron microscopy (SEM). The characteristic peak for green silver nanoparticles has been found, in the region 450 nm of the absorption spectrum. Therewith, SEM images showed spherical nanoparticles with dimensions between 18 -105 nm.