It should be remembered that the AC in the residues is biologically
active. Certainly this AC cannot pass into the intestinal mucosa in the
small intestine but it may exert antioxidant activity by a surface
reaction phenomenon (Serpen et al., 2007), and when these indigestible
residues reach the colon, the corresponding antioxidants
become fermentable substrate for bacterial microflora along with DF.