Starch modification to develop novel starch-biopolymer blends : state of art and perspectives

Native starches have limited use in industrial applications due to their poor water resistance, pasting, and mechanical properties. These behaviors can be amended by altering the starch structure by introducing ionic or hydrophobic groups in the starch structure. Structural modifications tend to stabilize the starch granules, impart hydrophilicity or hydrophobicity, heat resistance, desirable rheological properties, and increased processability. Physical modifications of starch can be achieved by various drying techniques, treatment with acids and alcohols, extrusion, etc. On the other hand, chemical modification can be achieved by chemical reactions, e.g., conversion, oxidation, dextrinization, cross-linking, and stabilization of starches. This review investigated the synthesis of modified starches and their physicochemical properties and use in various industries such as paper making, gelling agent, food additives, and pharmaceutics. In addition, the current understanding of modified starches as enzyme-resistant starch, biodegradable thermoplastic starch, and encapsulating and control release agent is also discussed