o:30947 The Impact of Ultrasound Waves on Polyphenol Yield and Antioxidant Capacity of Aloe vera L. Extracts Uticaj ultrazvučnih talasa na prinos polifenola i antioksidativni kapacitet Aloe vera L. ekstrakata en ABSTRACT Aloe vera L. is a tropical, drought-resistant, and perennial succulent native to Africa that later spread to other parts of the world. It contains anthraquinones, flavonoids, tannins, terpenoids, saponins, resins, polysaccharides, sterols, polypeptides, lectins, enzymes, chromones, fatty, amino and organic acids, vitamins, and minerals. Aloe and its extracts are widely used as active ingredients in laxative and antiobesity preparations and as a moisturizer, emollient, or wound-healing agent in pharmaceuticals, sunscreen, and other cosmetic formulations. Modern extraction procedures, such as ultrasound-assisted extraction, provide numerous benefits, including reduced solvent consumption, short extraction time, and a higher extraction yield, while operation and device are simple. Thus, in this study, A. vera extracts were prepared using dried and grinded leaves, 50% ethanol as the extraction medium, a solid-to-solvent ratio of 1:30, and an ultrasound probe at three different amplitude values, 20, 40, and 60% for 10 min. The impact of different amplitudes on the total polyphenol content and antioxidant capacity of the extracts (ABTS, DPPH, and CUPRAC assays) was investigated. There were no statistically significant differences between the polyphenol yield of the extracts obtained at various amplitudes (6.45±0.51, 6.83±0.32, and 6.95±0.23 mg gallic acid equivalents (GAE)/g of plant material). Anti-ABTS activity was significantly different between 20 and 40 or 60% of amplitude (1.20±0.05, 1.43±0.10, and 1.40±0.07 mmol Trolox/g). DPPH radical scavenging activity also increased (i.e. IC50 value decreased) at higher amplitudes (43.9±0.9, 41.6±1.1, and 39.4±1.0 mg/mL). According to the results of the CUPRAC assay, the antioxidant potential was the same for all prepared extracts (0.130±0.003, 0.131±0.002, and 0.125±0.004 mmol Trolox/g). Therefore, it can be concluded that radical scavenging ability did not correlate with the polyphenol yield of A. vera extracts, whereas cupric ion-reducing potential depended on the concentration of polyphenols. Aloe vera; antioxidants; polyphenols; ultrasound probe 1552100 978-86-82343-30-1 2023-10-02T07:14:29.952Z 44 yes 46 Aleksandra A. Jovanović University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor tehnoloških nauka 0000-0001-5394-0125 application/pdf 12211126 https://phaidrabg.bg.ac.rs/o:30947 no yes 18 70 92000004 11A29 Meeting point of the science and practice in the fields of corrosion, materials and environmental protection-Proceedings 50 Serbian Society of Corrosion and Materials Protection 2023