Polyphenolic Composition and Antioxidative Properties of Lemon Balm (Melissa officinalis L.) Extract Affected by Different Brewing Processes

Polyphenolic composition of lemon balm (Mellisa officinalis L.) aqueous extracts prepared as infusion and decoction were evaluated by high performance liquid chromatography/tandem mass spectrometry. All the samples showed a similar phenolic profile but presenting differences in the quantities found of each compound. Higher content was found in plant infusion extract compared to decoction process. During the prolonged time of extractions the contents of some compounds were changed. Rutin and caffeic acid contents were decreased in the infusion mode, while increased concentration was observed during decoction process. The antioxidant activities measured by Folin-Ciocalteu and CUOPRAC assays were higher for the extract prepared in decoction mode (1245 mg/g GAE and 4.91 mmol/g TRE, respectively) in comparison to infusion process (267 mg/g GAE and 2.62 mmol/g TRE).