<p>Recently, various studies have been conducted on eco-friendly nanofilms and packaging coatings. This study explores the innovation of nanocomposite based smart packaging by utilizing the molecular structure, thermal stability, barrier properties, pH sensitivity, and color responsiveness of nanoanthocyanin pigments extracted from papaver petals. Nanoanthocyanin was obtained via solvent-assisted ultrasonic extraction and incorporated into polylactic acid/carbopol matrices at concentrations of 0%, 0.5%, 1%, and 2% to fabricate biodegradable films. In this research, permeability parameters, molecular analysis, and colorimetric measurements across a pH range of 1 to 14 were conducted.The results showed that the highest oxygen permeability was observed in the control sample (T₀) (3.733 meq/KgO₂), while the lowest was found in the treatment (T₄) (1.567 meq/KgO₂), containing 2% nanoanthocyanin. In other words, increasing nanoanthocyanin concentration in biodegradable nanocomposite films reduced oxygen permeability compared to the control film. On the other hand, optimized levels of 2% nanoanthocyanin and 0.2% carbopol (T₄) improved thermal stability (149.80&#xa0;J/g) and crystallinity (44.2%) within the film matrix. Furthermore, the results revealed that treatment T₃ exhibited strong sensitivity to pH changes, especially between pH 2 and 6, positioning it as an ideal candidate for intelligent packaging. These advancements demonstrate that the presence of nanocarbopol as a reinforcing agent enhanced the network structure, uniformity, and flexibility of the films. Moreover, the incorporation of nanoanthocyanins and the improvement of their stability at specific pH levels make this nanocomposite a promising candidate for real-time visual monitoring of product freshness in environmentally friendly and sustainable packaging systems.</p> Graphical Abstract <p></p>