Composition and functional properties of enriched fiber products obtained from pumpkin (Cucurbita moschata Duchesne ex Poiret)

Enriched fiber products were obtained through ethanolic extraction of pumpkin (Cucurbita moschata Duchesne ex Poiret) mesocarp (AIR) or milled peel (C) or by drying of mesocarp (P). The composition and hydration properties of these products as well as glucose retention capacity were evaluated. AIR-fraction showed the highest swelling (41.8 ml/g dry sample) and water holding capacity (43 g/g dry sample) followed by P- (25 ml/g dry sample; 24 g/g dry sample) and C-fractions (22 ml/g dry sample; 27 g/g dry sample). AIR-fraction presented also the highest water retention capacity and rate of water binding and swelling. Hydration properties were dependent on fraction chemical composition: presence of rhamnogalacturonan I and other hydrophilic pectins with side chains were related to higher water absorption and swelling of AIR, while presence of lignin in C produced fiber-particle impermeabilization being probably responsible of its behavior as a barrier for water diffusion. In addition, AIR and C fractions showed values of glucose retention in vitro assayed, in accordance with other reported values of the literature.