Modification of carrot (Daucus carota Linn. var. Sativa Hoffm.) pomace insoluble dietary fiber with complex enzyme method, ultrafine comminution, and high hydrostatic pressure

Insoluble dietary fiber (DF) extracted from carrot pomace was modified by complex enzyme method, ultrafine comminution and high hydrostatic pressure and their structural, physicochemical, and functional properties were evaluated. Results showed that complex enzyme method increased the content of soluble DF to 15.07%, and the cholesterol adsorption capacity peaked; ultrafine comminution greatly improved the total antioxidant activities, DPPH radical scavenging capacity and antioxidant abilities in linoleic acid system of DF; high hydrostatic pressure led to a significant increase in capacities of water retention (7.14 g/g, 600 MPa), water swelling (10.02 mL/g, 500 MPa), oil retention (2.35 g/g, 500 MPa), cation exchange (2.29 mmol/g, 600 MPa), and glucose adsorption (2.634 mmol/g, 400 MPa). Furthermore, SEM showed that surface structures of all modified DF were loose. Overall, three kinds of modification methods have shown their respective advantages. Modified DF from carrot pomace can be applied as a functional ingredient in diverse food products.