Development and Evaluation of Starch‐Based Intelligent Films Functioned by Nano‐SiO ₂ and Black Currant Extract for Real‐Time Monitoring of Beef Freshness

ABSTRACT There is a growing demand in developing intelligent packaging because of its role in enhancing food safety and reducing food loss. In this study, we firstly investigated the rheological property of film‐forming solutions containing white lentil starch (WLS), nano‐SiO 2 (NS) and black currant extract ( BCE ) and found that the solutions exhibited shear thinning behaviour. Intelligent films were then developed using the film‐forming solutions, and their structural and functional properties were evaluated. Results showed that some intermolecular interactions between NS and BCE occurred in the WLS‐NS‐ BCE films. The addition of NS could markedly decrease water vapour permeability (WVP) (1.75 to 1.54 × 10 −13 g m −1 s −1 Pa −1 ) and increase tensile strength (TS) (21.74 to 33.4 MPa) of the WLS film. Incorporation of BCE significantly decreased WVP (1.54 to 1.25 × 10 −13 g m −1 s −1 Pa −1 ) of the WLS‐NS film. The WLS‐NS‐ BCE films had good antioxidant activity, thermal stability, light‐blocking property, pH sensitivity and visible colour change responsive to beef deterioration. The WLS‐NS‐ BCE films showed great potential for application in active and intelligent food packaging.