Pectin extracted from thermally treated olive oil by-products: Characterization, physico-chemical properties, in vitro bile acid and glucose binding

The pectin fraction released from steam-treated alperujo at 160 °C for 30, 45, and 60 min was purified and characterized. Differences were observed in the composition, and physical and biological activities of the pectin extracts, depending on the length of the thermal treatment. The extracts presented a low molecular weight in the range of 2–40 KDa, a high content of neutral sugars, and a high percentage of acetylation. In comparison with commercial pectins, the extracts had low water and high oil holding capacities, a normal emulsifying activity and a similar emulsion stability to that of apple pectin. For the three pectin extracts studied, the in vitro analyses showed considerable bile-acid binding activity and a glucose retardation index similar to the values obtained for citrus pectins. Thus, the pectins isolated from olive oil waste have suitable physical and biological properties for commercial use. Pectin extraction from alperujo, a sizeable by-product of the olive oil manufacturing process, would facilitate the use and subsequent reduction of this environmentally damaging organic waste.