Characterization of intelligent film based on chitosan/high-amylose starch and Portulaca oleracea L. flavonoids/anthocyanins/curcumin and its application in beef.

An intelligent film was developed using chitosan (C) and high-amylose (A) corn starch matrix (CA matrix), incorporating various concentrations of Portulaca oleracea L. flavonoids (POF) (2, 4, 6, and 8 g/L). Red cabbage anthocyanin (PCA) and curcumin (CR) were used as composite indicators (PC) to monitor beef freshness. The incorporation of POF enhanced the mechanical properties of the films, with the tensile strength decreasing from 58.06 MPa to 20.40 MPa and the elongation at break increasing from 93.12 % to 163.07 %. And make the films form a compact structure, raising the melting temperature to 163.23 °C and thereby bolstering the films' thermal stability. The decrease in transmittance of the film has better UV blocking ability, with a transmittance of 45.59 % at 600 nm for CA/PC/POF0.8 %. Furthermore, CA/PC/POF films slowed changes in pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and color of beef during storage. These findings suggest that CA/PC/POF films hold significant promise for application in intelligent film packaging for meat products.