Development of pH-responsive food packaging from chitosan incorporated with nano-curcumin and anthocyanin from black mulberry (Morus nigra L.)

Abstract

The growing demand for sustainable and intelligent food packaging has driven the development of biodegradable materials with real-time spoilage detection capabilities. Conventional petroleum-based packaging materials pose environmental and health risks due to micro- and nano-plastic contamination. This study presented pH-responsive chitosan films incorporating anthocyanin-rich black mulberry extract (BME) and nanocurcumin as natural color indicators for food freshness monitoring. The BME concentration was fixed at 0.9 mg/g chitosan, while nano-curcumin (0.03–0.3 g/g chitosan) varied to assess its effects on film micro-structure, physical properties, and functionality. Results showed that anthocyanins improved pH-sensitive color changes, making the films effective spoilage indicators. While low nano-curcumin concentrations reduced water vapor permeability (WVP) and tensile strength, higher levels enhanced optical properties, antioxidant activity, and color stability. The optimal formulation (0.21 g/g chitosan) provided a balance between mechanical strength and spoilage detection, making it suitable for meat and seafood applications. This research contributed to food technology and management by offering an eco-friendly alternative to synthetic freshness indicators, promoting food safety, shelf-life extension, and waste reduction