Lignocellulose nanofibers (LCNFs) reinforced starch-based intelligent film to detect chicken breast spoilage

Abstract

This study developed pH-sensitive starch-based films reinforced with peach pit-derived lignocellulose nanofibers (LCNFs) and blueberry anthocyanins (BA) at varying concentrations (0%, 10%, 25%, and 50%) for intelligent packaging of chicken. Anthocyanin was extracted from blueberries using acidified solvent extraction and incorporated into a starch/LCNF matrix to form films through solvent casting. The films were examined for their structural properties. Scanning electron microscopy (SEM) analyses confirmed that BA was successfully incorporated and uniformly dispersed within the starch/LCNF matrix. The tensile strength of the starch/LCNF/BA50 film was decreased by a factor of 4, while the elongation at break was increased to 12 times that of the control. Further, the color changes of films from reddish-pink at acidic pH (2) to greenish-yellow under alkaline conditions (pH 13) confirmed the excellent pH sensitivity of BA. Among all the tested films, the starch/LCNF/BA50 formulation, containing 50% BA, demonstrated the most sensitive color responsiveness. Additionally, the starch/LCNF/BA50 films exhibited strong antioxidant activity, with a DPPH radical scavenging rate of 53%. These films were subsequently used for intelligent chicken packaging under both ambient and refrigerated conditions. On the 10th day of storage (at 4 ± 1 °C), the pH and TBARS values of the chicken were recorded as 6.93 and 1.43 mg MDA per kg, both of which are indicative of significant lipid oxidation. Correspondingly, the starch/LCNF/BA50 film showed a significant color change from red to grayish-purple, further confirming its responsiveness to biochemical changes during spoilage. The developed pH-sensitive films could serve as effective indicators for monitoring freshness, supporting their potential use in intelligent food packaging systems.