Facile fabrication of sandwich-like anthocyanin/chitosan/lemongrass essential oil films via 3D printing for intelligent evaluation of pork freshness

In this study, chitosan (CH), mulberry anthocyanin (MA), and lemongrass essential oils (LEO) were used as an interlayer using a 3D printer. Further, cassava starch (CS) was used as a protective layer to form indicator films. The indicator films containing LEO showed significant antioxidant and antibacterial properties, and the release rate of LEO increased with a rise in pH. When chilled pork spoiled, the color of the indicator films changed from red to gray-blue, and the RGB values could be automatically analyzed by a smartphone application to determine pork freshness. These films hold implications as easy-to-use indicators of meat freshness, with great potential for monitoring food spoilage, as part of an intelligent packaging system.

Automated summary

Chitosan, mulberry anthocyanin, and lemongrass essential oils were used to create indicator films using 3D printing technology, with cassava starch as a protective layer. These films exhibited antioxidant and antibacterial properties, with the sensitivity increasing as pH levels rose. When chilled pork spoiled, the color change in the indicator films could be analyzed automatically by a smartphone app to determine meat freshness.