Phenolic Profile and Antioxidant Capacity of Selected Medicinal and Aromatic Plants: Diversity upon Plant Species and Extraction Technique

Abstract

Phenolic content and antioxidant capacity (AC) was evaluated in extracts of bay, sage and thyme leaves, myrtle leaves and berries, and sea buckthorn berries obtained by conventional (CE) and advanced extraction techniques [ultrasound-assisted (UAE) and accelerated solvent extraction (ASE)] using 80% acetone (v/v) as extraction solvent. Extracts were analyzed for phenolic content using UPLC/ESI MS2 and AC by ORAC method. Results indicated the variations in the phenolic composition and concentrations among analyzed plant species and applied extraction methods. Flavonoids showed to be the predominant phenolic group represented by flavonols kaemferol-3-O-hexoside (182.58–321.45 mg 100−1 g dm) and quercetin-3-glucoside (253.05–315.67 mg/100 g dm) in bay leaves, by flavonol isorhamnetine-3-O-hexoside (27.76–45.16 mg/100 g dm) in sea buckthorn berries and by flavone luteolin-7-O-glucoside (470.27–781.78 mg/100 g dm) in sage leaves. Among the phenolic acids, hydroxybenzoic acids and their derivates were the predominant phenolic group in thyme leaves and myrtle. Statistical analysis showed that ASE contributed to the highest content of total flavonols, flavones, hydroxycinnamic and hydroxybenzoic acids as well as AC. CE was more efficient method for the extraction of total flavan-3-ols, while UAE showed the highest efficiency in extraction of total anthocyanins. Analyzed plant extracts proved to be a rich source of various phenolics and results indicated suitable extraction methods for target phenolic compounds characteristic for certain plant species.