Selective green extraction of polyphenols from Melissa officinalis L

In the last years natural antioxidants such as polyphenolic compounds have became of great interest for the formulation of functional foods and have been broadly investigated for their ability to act as free radical scavengers, and suitable supplements in the prevention of some cardiovascular and neurodegenerative diseases. Lemon balm (Melissa officinalis) is well known not only for its culinary properties, but also for curative properties (sedative, spasmolitic, antitumoral and antioxidant). Recent studies have shown that protocatechuic acid, caffeic acid and rosmarinic acid are the most representative phenolic compounds in this plant [1]. Nowadays, the design of efficient and environmental friendly extractive protocols represents an important topic research for the potential applications of plant extracts in the formulation of functional foods and nutraceutical products. Ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE) are green techniques that could dramatically reduce extraction times and solvent volumes increasing product yields and preserving the extract from thermal degradation [2-5]. In the present work different UAE and MAE of dried Lemon balm aerial parts were compared to evaluate their efficiency and their selectivity. We also experimented dry-extraction in ball mill in the presence of -cyclodextrin (-CD) by treatment of rewetted vegetal material. Extraction yields, total phenols content and rosmarinic acid content have been determined. In general, rosmarinic acid is always the main component of total phenols while ethanol results to be the best solvent for both UAE and MAE procedures