Smart and sustainable pectin/CMC-nanocurcumin films for spoilage detection and preservation of fresh pork.

This study aimed to develop sustainable bio-based packaging materials in the form of pectin/carboxymethyl cellulose (P/CMC) films incorporated with nanocurcumin (NCur) as an active coating and smart indicator in pork preservation. Nanocurcumin was added at different concentrations: 0, 0.8, 1.6, 2.4, and 3.2 g/100 g polymer. Some properties of the films, including color, light transmittance, color sensitivity to pH, moisture, and antioxidant activity, were investigated. The results showed that the addition of nanocurcumin increased the film thickness, reduced moisture, increased UV barrier ability, and antioxidant activity. FTIR analysis indicated that there was no chemical interaction between nanocurcumin and pectin/carboxymethyl cellulose matrix, so nanocurcumin still retained its valuable properties. The addition of nanocurcumin at a concentration of 1.6 g/100 g polymer was considered the most effective and therefore applied for pork preservation. The coating by dipping reduced ammonia formation, inhibited microbial growth, and minimized color changes in pork during storage. As a result, the shelf life of pork could be extended from 3 to 11 days at 4 °C compared to the uncoated sample. PCA analysis also confirmed the effectiveness of film coating. Furthermore, the pectin/carboxymethyl cellulose with incorporation of 1.6 g NCur/100 g polymer films showed a distinct color change according to pH, showing a good correlation between color change in response to pork spoilage and ammonia concentration (R2 > 0.9). These findings suggest that the P/CMC/NCur film can be applied as a smart and active coating for pork preservation and real-time freshness monitoring, offering promise in reducing food loss, promoting sustainable packaging innovation, ensuring responsible production, and supporting climate action.