title: Quality evaluation of different preparations of dry extracts of birch (Betula pendula Roth) leaves.
abstract: Qualitatively prepared dry extracts are advantaged over conventional fluid extracts. Extracts of Betula pendula Roth leaves possess mild diuretic effects and anti-inflammatory activity. In this work, the spray-drying and lyophilisation processes were evaluated for producing dry extracts of birch leaves. The purpose was to identify the best drying method that provides the highest content of phenolic compounds and possesses greatest antioxidant activity. Predominant compounds hyperoside and chlorogenic acid were chosen as markers for the quantitative control of phenolic compounds. Their determined amounts in hydroalcoholic birch leaf extract were 15.85 and 8.77 mg/g of dry residue, respectively. Insignificant differences were determined in spray- and freeze-dried extracts. In the antioxidant profile, hyperoside (28.9 μmol TE/g dw) and chlorogenic acid (22.8 μmol TE/g dw) possessed strongest ferric-reducing activity. Also, no significant differences of antioxidant activity were determined in the spray- and freeze-dried extracts.
authors.affiliation: a Department of Pharmacognosy , Lithuanian University of Health Sciences , Eivenių Street 4, LT-50161 Kaunas , Lithuania.
authors.forename: Lina
authors.initials: L
authors.lastname: Raudonė
authors.forename: Raimondas
authors.initials: R
authors.lastname: Raudonis
authors.forename: Valdimaras
authors.initials: V
authors.lastname: Janulis
authors.forename: Pranas
authors.initials: P
authors.lastname: Viškelis
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D029662:Betula / Q000737:chemistry*; D002726:Chlorogenic Acid / Q000032:analysis; D015394:Molecular Structure; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry; D011794:Quercetin / Q000031:analogs & derivatives / Q000032:analysis
chemical_list: D000975:Antioxidants; D010636:Phenols; D010936:Plant Extracts; D002726:Chlorogenic Acid; C021304:hyperoside; D011794:Quercetin
keywords: Betula pendula; FRAP; antioxidant; birch; dry extract; phenolic