Sustainable PVA/Chitosan/Starch based Smart Packaging Films with Ghangaru-Anthocyanins for Real-Time Chicken Meat Freshness Detection

Sustainability has driven an increasing concern for affordable, renewable, and biodegradable alternatives in food packaging. Bio-based and biodegradable packaging incorporating biosensors and indicators has attracted considerable attention for its ability to both protect food and convey freshness information. This study presents a sustainable, biodegradable packaging material that acts as a smart ammonia and food spoilage indicator. The composition includes a blend of polyvinyl alcohol (P) and starch (S) combined with Ghangaru (Pyracantha crenulata) anthocyanins (G-ATH), fabricated via a casting and drying method with glycerol as a crosslinking agent. For comparison, pH-sensitive films were developed using polyvinyl alcohol, chitosan, and starch with the incorporation of G-ATH to monitor chicken meat freshness. The G-ATH film exhibited distinct color changes and UV–visible spectra across various pH levels (2 to 12). The reversible molecular transformations of the infused anthocyanin (G-ATH) in response to pH are responsible for the color-changing behavior of the film. Among the formulations, the S/P/G-ATH film demonstrated superior antioxidant activity (30.45%). On the other hand, S/C/G-ATH showed high moisture retention (14.69%) and high opacity (10.72), and C/P/G-ATH performed better in water vapor barrier properties (32.68 WVP (10^–11 gm⁻¹ s⁻¹ Pa⁻¹) and WCA (60.79°). As a proof of concept, the film was evaluated for monitoring the freshness of chicken meat stored at 25 °C. Notably, the film changed color from dark red to brown within 36 h as the total volatile basic nitrogen (TVB-N) level approached the rejection limit of 30 mg/100 g and pH reached 8.42 because spoilage of meat produces nitrogenous substances having alkaline properties, which increases the pH. The results of this study suggest that G-ATH-enriched films have the potential to be advanced packaging materials for detecting food spoilage.