Development of pH-Responsive Food Packaging from Chitosan Incorporated with Nano-Curcumin and Anthocyanin from Black Mulberry (Morus nigra L.).

Abstract

This study aims to develop active and intelligent packaging films by incorporating chitosan with natural color indicators, such as anthocyanin-rich black mulberry extract (BME) and nano curcumin. The BME content was held constant at 0.9mg/g chitosan, while various concentrations of nano-curcumin (0.03, 0.12, 0.21, 0.3 g/g chitosan) were introduced to evaluate their impact on the microstructure, physical attributes, and functionality of the chitosan film (Control). The findings reveal that anthocyanin significantly enhances the properties of chitosan films. Although the study mentions that the addition of nano-curcumin brings undesired effects, such as decreased water vapor permeability (WVP), tensile strength properties, limited color-indicating ability at low concentration (C03), and reducing color variation at high concentration (C07 and C10), there is a substantial gradual improvement in optical characteristics, moisture content, swelling ratio, antioxidant properties, and color stability aligning with an increasing concentration of nano curcumin. Structural properties and elongation at break were reported to be enhanced at lower nano-curcumin levels (<0.12g/g chitosan). The results suggest that a nano-curcumin concentration of 0.21g/g chitosan (C04) represents the optimal ratio for incorporation with anthocyanin into chitosan-based films, particularly for indicating the spoilage of meat and aquatic food products.