Fabrication of Halochromic Carboxymethylcellulose Strips Integrated with Anthocyanins for Real-time Visual Detection of Meat Quality

Ensuring the quality of packaged meat is a growing concern for modern consumers, to avoid purchasing spoiled products. This study fabricated halochromic carboxymethyl cellulose strips via solvent-casting, incorporating anthocyanins extracted from Tradescantia pallida and Basella alba as natural pH-sensitive indicators. Fabricated smart strips were extensively characterised using FTIR, SEM, AFM, XRD and UV-DRS. Water contact angle measurements indicated the hydrophilic nature of strips, with values subceeding 90°. Integrating anthocyanins significantly improved the mechanical performance, increasing tensile strength from 14 to 30 MPa. Modified strips also exhibited enhanced antioxidant activity, increased by over 60%, demonstrated antibacterial efficacy with inhibition zones above 7 mm and reduced water vapour permeability. Biodegradability tests revealed that all strips underwent more than 85% weight loss within 48 days, confirming their environmental compatibility. Colourimetric analysis demonstrated distinct colour transitions across a wide pH range, from acidic to alkaline, confirming the halochromic nature. Ammonia vapour sensing tests showed over 90% sensitivity, indicating high responsiveness to volatile basic compounds. For real-time applications, strips were used to monitor the freshness of chicken meat stored at room temperature and under refrigeration. TVBN increased by 58 mg/100 g at room temperature and 22 mg/100 g under refrigerated conditions by the 6th day, correlating with evident colour changes in strips. These findings highlight the potential of anthocyanin-integrated carboxymethyl cellulose strips as effective, eco-friendly indicators for real-time meat freshness monitoring, offering strong pH sensitivity, gas detection capability and functional biodegradability suitable for smart packaging applications.

Graphical Abstract