Hydrophobicity Improvement of Edible Corn Starch / Bovine Gelatin Blend Biofilms

Starch was chemically modified through reactive extrusion with paraffin (P) and maleic anhydride to prepare starch-g-P as well as anhydride acetic (AA) to obtain starch-g-AA. Afterwards, it was combined with starch/gelatin (1:1) blend to decrease its hydrophilicity and improve processability. Both the binary and ternary blends plasticized with water and sorbitol and then were reprocessed to mix them and form edible biofilms. These all were done within a Brabender laboratory twin screw extruder. The resultant films were assessed and compared in terms of tensile properties, contact angel, water absorption and water vapor permeability (WVP). Also, effects of retrogradation and aging on tensile properties have been investigated. According to the results, introducing starch-g-P into the starch/gelatin blend increases contact angle, decrease water uptake and WVP besides comparable mechanical properties. However, WVP increased and tensile strength decreased in the ternary blends including starch-g-AA although, contact angle increased and water absorption reduced.

کلیدواژه ها:

Biodegradable Films ، Natural Polymers ، Film Extrusion ، Hydrophilicity