Comparative analysis of binder polymer matrices for developing green pH-responsive indicating ink solutions based on anthocyanin for food packaging applications

Traditional packaging ink solutions comprise organic solvents and petrochemical-derived materials, which are environmentally hazardous and highly harmful to human health. Therefore, the demand for novel, green, sustainable packaging ink solutions is increasing. Anthocyanin-based indicating ink solutions were prepared by varying the types and amounts of binders, and their properties were analyzed. The binder affected the chemical bonding, thermal stability, contact angle, and viscosity of the ink solution. The viscosity influenced the coating thickness, reactivity, and color. Ink solutions based on carboxymethyl cellulose (CMC) and chitosan (CT) displayed significant changes in viscosity (35.45-1387.63 mPa·s), exhibiting shear-thinning and thixotropic behaviors, which are excellent characteristics for ink solutions. During kimchi fermentation, the total color difference ranged from a minimum of 6.38 to a maximum of 22.04, demonstrating excellent indicating performance. CMC and CT displayed high potential for use as binders in anthocyanin-based, pH-responsive indicating ink solutions for application in food packaging.