Preparation and evaluation of a novel intelligent starch-based film with both color indication and antibacterial function

The study has developed an intelligent starch-based film to monitor pH changes and inhibit undesired microbial growth in foods. The anthocyanin (ANT) and rosemary essential oil (REO) were used to achieve simultaneous colorimetric indication and antimicrobial activity. The study found that both the ANT and the REO can improve the mechanical properties with a relatively smooth cross-section surface. Meanwhile, the water vapor permeability (WVP) increased and the oxygen permeability (OP) decreased significantly. Additionally, there was a distinguishable change of colors as the film was immersed in solutions of pH value ranging from 1.0 to 14.0. Moreover, the developed film showed excellent antimicrobial activity for two typical undesired microorganisms in foods, Bacillus subtilis and Aspergillus niger. The results indicated that the developed film have great potential to use as a diagnostic tool for the detection of food spoilage. Novelty Impact Statement This work developed a novel intelligent film that is capable of monitoring pH changes. The results showed that there was a distinguishable change of colors as the film was immersed in solutions with different pH. Moreover, the developed film also showed excellent antimicrobial activity for two typical undesired microorganisms.