Smart Starch-Gelatin Films Incorporated with Curcumin

Abstract

In this study, we developed a starch-gelatin film incorporated with synthesized curcumin to be used as a pH-sensitive smart material for food packaging. The film-forming mixture contained five components: starch, gelatin, glycerol, acetic acid and curcumin. The interactions of the components and their effects on the film properties were investigated by using response surface methodology with central composite experimental design. The results showed impacts of the contents of these components as independent variables on tensile strength, elongation at break, Young’s modulus and solubility of the films. The contents of starch, gelatin and glycerol significantly affect these properties, while acetic acid and curcumin do not (p<0.05). Also, it was shown that the incorporation of curcumin provided the film with the capacity to sense pH changes from neutral to basic (yellow at pH ≤ 8 and orange-red at pH ≥ 9).