Antioxidant polyphenols of Madeira sorrel (Rumex maderensis): How do they survive to in vitro simulated gastrointestinal digestion?

• Published in: Food chemistry Vol. 259; pp. 105 - 112
• Main Authors: Spínola, Vítor, Llorent-Martínez, Eulogio J., Castilho, Paula C.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-09-2018
• Subjects: Antioxidant activity; Flavonoids; HPLC–MS; In vitro digestion simulation; Rumex maderensis; HPLC–MS; Flavonoids; In vitro digestion simulation; Rumex maderensis; Antioxidant activity
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2018.03.112

•The phenolic composition of Rumex maderensis was determined for the first time.•Leaves and flowers were composed mainly by flavones and stems by proanthocyanidins.•The contents of phenolic compounds decreased after in vitro digestion.•The in vitro antioxidant activities were remarkably changed after digestion.
In this work, we report the phytochemical profile and antioxidant activity of different morphological parts of Rumex maderensis Lowe (Polygonaceae), a wild leafy-vegetable growing in Madeira Island (Portugal). Methanol extracts from leaves, flowers, and stems were submitted to high-performance liquid chromatography with mass spectrometry detection to obtain the phytochemical profile, which allowed the identification of 86 polyphenols (about 70% C- and O-flavonoids) and 9 non-phenolic compounds. In vitro antioxidant activities were measured against ABTS, DPPH, nitric oxide and superoxide free radicals. Then, the samples were subjected to an in vitro digestion, observing a decrease of about 50% in both the content of phenolics and the antioxidant activity. However, relevant antioxidant capacity was still observed after the simulated digestion. Therefore, this study supports the consumption of R. maderensis as an interesting foodstuff and a dietary source of antioxidant phytochemicals that survive the gastrointestinal digestion process.