Provided are methods of expanding an activated pectin-containing biomass composition to form an expanded pectin-containing biomass composition, and compositions containing the activated pectin-containing biomass composition or the expanded pectin-containing biomass composition. The activated pectin-containing biomass composition and the expanded pectin-containing biomass composition contains pectin in an amount from at or about 20 wt% to at or about 50 wt%, and cellulosic fiber in an amount from at or about 80 wt% to at or about 50 wt%.