Application of ultrasound assisted extraction to isolate phenolic compounds from laurel

Lovor je mediteranska biljka bogata biološki aktivnim spojevima, a posebice fenolnim spojevima koji značajno doprinose njegovom antioksidacijskom kapacitetu. Biološki aktivni spojevi se iz biljnog materijala izoliraju različitim postupcima ekstrakcije među kojima nove tehnike poput primjene ultrazvuka zauzimaju značajno mjesto. Cilj ovog rada bio je izolirati i odrediti ukupan udio fenolnih spojeva u ekstraktima lovorovog lista dobivenima ekstrakcijom potpomognutom ultrazvukom pri različitim uvjetima. Ekstrakcija je provedena uz 50%-tnu, 70%-tnu ili 100%-tnu amplitudu ultrazvuka kroz 5, 10 ili 15 minuta. Otapala koja su korištena za ekstrakciju su 50%-tni i 70%-tni etanol. Udio fenolnih spojeva određen je spektrofotometrijski te se ovisno o uvjetima ekstrakcije i primijenjenom otapalu kretao u rasponu od 7,90±0,40 do 26,69±1,01 mg GAE/ g uzorka. U dobivenim ekstraktima lovorovog lista FRAP metodom određen je i njihov antioksidacijski kapacitet u rasponu od 111,80±5,41 do 263,16±3,26 μmol TE/ g suhog uzorka. Najveća koncentracija fenolnih spojeva (26,69±1,01 mg GAE/ g uzorka) postignuta je ekstrakcijom pri amplitudi ultrazvuka od 50% tijekom 10 minuta uz 70%-tni etanol kao otapalo.Laurel is a Mediterranean plant rich in biologically active compounds, specifically in phenolic compounds which significantly contribute to its antioxidant capacity. The biologically active compounds can be isolated from the plant material by various extraction methods, among which new techniques such as the application of ultrasound occupy a significant place. This study aimed to isolate and determine the total proportion of phenolic compounds in bay leaf extracts obtained by ultrasound assisted extraction with different parameters. Extraction was performed at 50%, 70% or 100% ultrasound amplitude for 5, 10 or 15 minutes. Solvents used for the extraction were 50% and 70% ethanol. The total proportion of phenolic compounds was determined spectrophotometrically and depending on the extraction conditions and the solvent used it ranged from 7.90±0.40 to 26.69±1.01 mg GAE / g sample. The antioxidant capacity of bay leaf extracts was determined by the FRAP method and it ranged from 111.80±5.41 to 263.16±3.26 μmol TE/ g dry sample. The highest concentration of phenolic compounds (26.69±1.01 mg GAE / g sample) was achieved at an amplitude of 50% for 10 minutes with 70% ethanol as solvent