Chemical characterization and antioxidative properties of Polish variety of Morus alba L. leaf aqueous extracts from the laboratory and pilot-scale processes

Ewa Flaczyk, Joanna Kobus-Cisowska, Monica Przeor, Jozef Korczak, Marian Remiszewski, Eugeniusz Korbas, Maciej Buchowski

Department of Food Service and Catering, Poznan University of Life Sciences, Wojska Polskiego, Poznan, Poland.
Institute of Agricultural and Food Biotechnology Department of Food Concentrates and Starch Product, Starolecka, Poznan, Poland.
Vanderbilt University, Department of Medicine, Nashville, Tennessee, USA.

DOI: 10.4236/as.2013.45B026                

Abstract

White mulberry tree (Morus alba L) is cultivated throughout Asia and Europe, including Poland. The leaves and root bark preparations from Morus alba have been used in traditional phytomedicine. The objective of the present study was to compare chemical composition and antioxidative activity of aqueous extracts prepared from Polish variety of Morus alba leaves at the laboratory (L) and pilot plant scale (PP) conditions. Proximate composition, phenolic acids profile (HPLC/MS), flavonol glicosides (HPLC/ MS), polyphenols (Folin-Ciocalteu assay), and the antioxidant activity (ABTS and DPPH assay) of the extracts were determined. The main phenolic compounds were identified as gallic, protocatechuic, phydroxybenzoic, vanillic, chlorogenic, caffeic, p-coumaric, ferulic, and sinapic acids. Chlorogenic acid was the main phenolic constituent of both extracts. The flavonols fraction contained rutin, quercetin 3-β-D-glucoside, and kaempferol 3-β-D- glucopyranoside. Total concentration of phenolic compounds were 7.9 g and 14.4 g gallic acid equivalent/100 g extract, and antioxidant activity was 137.1 and 214.1 μMol Trolox equivalent/g dry weight for the PP and L extracts, respectively. We concluded that current pilot plant process is less efficient than laboratory process at the aqueous extraction of bioactive components from Morus alba dried leaves. Potential improvements may include increasing efficacy of the extraction, decreasing losses of bioactive components during the process, or both.

Keywords

Morus Alba Leaves; Pilot Plant Scale; Antioxidant Activity; Phenolic Acid; Flavonols; HPLC

Conflicts of Interest

The authors declare no conflicts of interest.

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