Preparation of Corn Starch‐Based Antibacterial Indicator Film Containing Red Amaranth Anthocyanins and Cellulose Nanofibril‐Emulsified Clove Essential Oil and Its Application in Monitoring the Freshness of Chicken

ABSTRACT An antibacterial indicator film was prepared with corn starch as film‐forming matrix, red amaranth anthocyanin (RAA) as indicator, cellulose nanofiber (CNF) as emulsifier, and clove essential oil (CEO) as antibacterial agent, and was used to detect the freshness of food. The results showed that RAA showed significant color changes at different pH conditions. When the pH value increased, the color of the solution changed from pink to green and finally to yellow. Meanwhile, the addition of CNF and CEO improved the mechanical properties and antibacterial properties of the film, respectively. Compared with pure starch‐based films, when the ratio of CNF to CEO was 6:1, the tensile strength increased by 13.6%, and the water contact angle and elongation at break of the film increased by 57.6% and 60.8%, respectively. The antibacterial capacity against Staphylococcus aureus and Escherichia coli reached 120.54 and 105.73 mm 2 , respectively. When the film was used to monitor changes in chicken quality, the color difference (Δ E ) of the film and the total volatile nitrogen (TVB‐N) show a good linear correlation ( R > 0.94), and the quality of chicken can be judged by observing the color changes of the film. In addition, the addition of CEO reduced the release of RAA in the antibacterial indicator film, and the prepared film has good stability. This film has great application potential in food freshness indication. Summary The prepared film has good mechanical, antibacterial, and antioxidant properties. The freshness of chicken can be quickly detected through an obvious change in film color (Δ E > 1). The prepared films have good stability and reduce the problem of anthocyanin leaching.