Curcumin as a Dual-Function Sensor and Active Agent in Sustainable Food Packaging for Spoilage Detection

Introduction: Concerns over synthetic additives in packaging, along with the risk of spoilage during storage, caused by pathogens, adulterants, and gases like volatile amines and CO₂, have driven interest in sustainable, biodegradable, and intelligent food packaging. These issues highlight the need for effective monitoring and detection strategies. Curcumin, a natural polyphenolic compound from Curcuma longa, exhibits antimicrobial and pH-responsive colorimetric properties, making it a promising dual-function component in eco-friendly food packaging systems.

Methods: Curcumin was incorporated into biodegradable polymer matrices (cross-linked potato starch and citric acid) using the solvent casting method. This is attached to the packaging films, and performance analysis was conducted, including color responsiveness, antimicrobial efficacy, mechanical strength, and biodegradability. This curcumin-based film is employed to monitor and detect the spoilage of paneer and extend its shelf life.

Results and Conclusions: The curcumin-based starch-citric acid film exhibited clear pH-sensitive color changes from yellow to reddish-brown in response to volatile amines released during paneer spoilage, enabling effective visual detection. Antimicrobial testing showed notable inhibition zones against E. coli, confirming curcumin’s bioactivity. The film maintained good tensile strength and flexibility and was suitable for packaging applications. Biodegradability tests demonstrated rapid degradation under composting conditions. When applied to paneer, the film extended shelf life by a week under refrigerated conditions compared to the unpackaged control, validating its dual role as an active and intelligent packaging material for dairy product preservation.