Extruded low density polyethylene-curcumin film: A hydrophobic ammonia sensor for intelligent food packaging

A hydrophobic film was developed using low density polyethylene (LDPE) and curcumin with the melting extrusion method. The hydrophobic nature of the LDPE endowed the film with good stability to pH buffer solutions, namely without obvious color change or curcumin leaching, when immersed in pH buffer solutions. The LDPE-curcumin composite film was sensitive to ammonia (NH3), and the limit of detection (LOD) of LDPE-curcumin film to NH3 at 90 % RH was 0.18 μM. When the LDPE-curcumin film was used to monitor beef and silver carp spoilage at 4 °C, it showed light yellow-to-light brown color changes along with the storage time, resulting from the increasing TVB-N contents of the meat samples. As the developed LDPE-curcumin film was totally non-toxic and suitable for industrial production in a large scale, there will be a good potential for its application in intelligent food packaging.