Preparation and characterization of indicator films from chitosan/polyvinyl alcohol incorporated Stachytarpheta jamaicensis anthocyanins for monitoring chicken meat freshness

Abstract

In this study, a novel multifunctional intelligent/active packaging material fabricated by immobilizing Stachytarpheta jamaicensis extracted (SJE) anthocyanins in a polymer matrix consisting of chitosan (CS) and polyvinyl alcohol (PVA) is described. The addition of SJE enhanced the tensile strength, barrier, and antioxidant activity of the films, and by increasing the SJE content, the tensile strength of the film reached 38.79 ± 3.52%, and antioxidant activity was found to be 81.72 ± 2.73%. The minimum oxygen permeability was 3.185 ± 0.532 × 10⁻⁶ (cc m⁻¹ 24 h atm), and the minimum water vapor permeability was 18.39 ± 0.18 g m⁻¹ h⁻¹. The UV-vis light transmittance and elongation at break were reduced when different contents of SJE were incorporated into the CS/PVA (CP) matrix. The smooth SEM images revealed that the miscibility and compatibility of the CP matrix with SJE anthocyanins were tolerable. The color of the film changed from pink to dark yellow when pH increased from 1 to 13. TGA profile indicated that the addition of SJE to CP significantly enhanced the thermal stability of the film. The prepared composite film changed color from pink to dark yellow when the estimated volatile base nitrogen content in the meat was 21.71 ± 0.59 mg/100 g. Hence, the prepared film with SJE can be used for the chicken meat packaging in real-time freshness monitoring at room temperature.