Polyphenols of artichoke fractions and their in-vitro digestion

Abstract

This study was aimed to determine total polyphenols (TP), total flavonoids (TF), chlorogenic acid (CA), antioxidant capacity (AC) and in -vitro bioaccessibility of polyphenols (as gastric and intestinal stages) of the extracts from artichoke fractions (head, bract and stalk) using different solvents (80% ethanol, 80% methanol and water). The results showed that artichoke fraction and solvent used significantly affected all parameters measured (P<0.05). TP and TF contents of the samples varied in the range of 1.74-5.52 mg gallic acid equivalents per gram of dry matter (mg GAE g-1 DM) and 1.30-7.34 mg rutin equivalents per gram of dry matter (mg RE g-1 DM), respectively. AC of the samples varied from 433.73 to 1243.21 mmol of ascorbic acid equivalents per 100g of dry matter (mmol AAE 100g-1 DM).TP and AC of the extracts varied depending on artichoke fraction and solvent used after in-vitro digestion. They were found to be lower than their initial (before digestion) values. Bioaccessibility of the polyphenols was in the range of 17.36-64.37%. CA detected in all extracts except water extracts of artichoke head (AH) and artichoke stalk (AS). These results suggest that artichoke bract (AB) and AS which are artichoke byproducts might represent a potential source of natural antioxidants as well as AH.