Antioxidant–polysaccharide conjugates for food application by eco-friendly grafting procedure

In the present study, catechin–alginate and catechin–inulin conjugates were obtained by adopting free radical-induced grafting procedure. In the aim to synthesize the antioxidant–polysaccharide conjugates, ascorbic acid/hydrogen peroxide redox pair was employed as water-soluble and biocompatible initiator system. The insertion of catechin onto the polymeric backbones was verified by performing FT-IR, DSC and fluorescence analyses and molecular weight distributions were analyzed by GPC. Finally, the antioxidant properties of the obtained conjugates were evaluated and compared with that of blank alginate and blank inulin, treated in the same conditions but in absence of catechin. The good antioxidant activity showed by functionalized materials confirmed the efficiency of the adopted reaction method to impart peculiar characteristics to macromolecules of natural origin for specific industrial applications. This kind of systems, indeed, could be very useful in the optimization of food preservation and to help manufacturers in elaboration of new food products and packaging.