Betacyanin–curcumin smart films for detecting fresh chicken quality in real time

Abstract

pH-based indicators play an important role in ensuring food safety by providing a real-time visual indication. The objective of this study was to evaluate the potential of the natural colors of turmeric (curcumin) and beetroot peel (betacyanin) as colorimetric pH indicators for the determination of chicken freshness. For pH changes, curcumin (CR), betacyanin (BPE), and a 1 : 1 mixture of CR and BPE were tested with different buffer systems. The sensitometric films were prepared by dispersing these dyes at 1, 2, 5 and 10% concentrations into a biopolymeric film matrix of sodium alginate and almond gum. Formulation with a 10% concentration exhibited superior color retention and visual sensitivity. Film characterization was performed, including moisture content, solubility, and FTIR analysis. The response of the film was evaluated in fresh chicken stored at room temperature and refrigerated temperature (4 °C). The obtained results, including stability, color change correlation with total volatile basic nitrogen (TVB-N) levels, and 20-day film durability, confirm the effectiveness of these films as a non-destructive food quality monitoring system. The combination of curcumin and betacyanin provided enhanced pH sensitivity, a broader detection range, and improved visual clarity, making it more effective than single-indicator systems for real-time spoilage monitoring. This study presents a novel, affordable, biodegradable smart packaging solution for meat freshness monitoring in real-time, which has the potential to increase food safety and reduce food waste.