Chemical composition and technofunctional properties of carrot (Daucus carota L.) pomace and potato (Solanum tuberosum L.) pulp as affected by thermomechanical treatment

Abstract Fiber rich by-products derived from primary agri-food production such as carrot pomace and potato pulp are available in large quantities, but their functional properties do not necessarily meet the requirements for use specific food applications. Thermomechanical treatment (extrusion) of changes both dietary fiber polysaccharide structures technofunctionality materials. Solubility constituents changes, resulting higher levels water- ethanol-soluble poly-/oligosaccharides. On a structural level, particularly arabinans galactans neutral side chains type I rhamnogalacturonan were degraded under thermomechanical stress. Galacturonic acid portions (preferably homogalacturonan or I) degree methylation also negatively affected. water absorption increased up to three times following extrusion, whereas decreased with extrusion processing. The observed, enhanced swelling behavior extruded was accompanied by complex viscosity dispersions. Swelling particles largely (up 25 times) highly viscous pastes. Phytochemicals retained 50%, heat-induced contaminants formed only small extent 8.1 mg 5-hydroxymethylfurfural·kg − 1 dry matter pomace; 71 µg acrylamide·kg pulp). Graphical abstract