Preparation and Characterization of Corn Starch/Acai Berry Anthocyanin Antimicrobial Indicator Film

ABSTRACT In recent years, research into indicator, environmentally friendly packaging materials with visual monitoring capabilities has become increasingly important due to heightened awareness of food safety and environmental protection. Starch‐based films are ideal due to biodegradability and film‐forming properties. This study prepared a novel antibacterial indicator film using corn starch (CS) as the matrix, tea tree essential oil (TTO) emulsified with nanocellulose (CNF) as the antibacterial agent, and acai berry anthocyanin (BBA) as the pH‐sensitive indicator, aimed at monitoring the freshness of chicken. Results revealed a 29.8% reduction in tensile strength and 73.6% decline in elongation at break for the indicator film, whereas water contact angle increased by 75.8%, indicating enhanced hydrophobic character, the glass transition temperature increased by 12.4%. Additionally, the free radical scavenging activity improved by 72.7%. The film exhibited effective antibacterial performance, with inhibition zone areas of 148.38 mm 2 against Escherichia coli and 160.12 mm 2 against Staphylococcus aureus . Throughout chicken storage, the indicator film transitioned from pink to yellow, signaling progressive meat spoilage and quality decline. The incorporation of tea tree essential oil effectively slowed the release of acai berry anthocyanins, thereby enhancing the functional stability of the film.