Preparation of food packaging composite films composed of corn starch with nano Fe-HIA

Developing biopolymer-based smart active packaging materials with antimicrobial and colorimetric ammonia-sensitive function has become an emerging strategy to ensure food safety. To address the shortcomings of biopolymer film material with single function, weak mechanical and barrier performances, innovative corn starch (CS)-based smart active packaging film with antimicrobial and colorimetric ammonia-sensitive function was manufactured by constructing novel nano Fe-HIA complex as functional filler. Results revealed that the manufactured CS/Fe-HIA films had uniform and intact morphologies resulting from robust hydrogen bonds between CS and Fe-HIA, and displayed significantly improved performances dependent on Fe-HIA content. Specially, the CS-based smart active film with relatively high Fe-HIA content (5 wt%) was much more sensitive to ammonia, showing noticeable color transition from brown to yellow. The well distributed Fe-HIA significantly promoted hydrophobicity (96.0°), water barrier, thermal stability, mechanical strength (6.8 MPa), and UV-blocking (100 %) performances of the film. Furthermore, CS/Fe-HIA films possessed good antibacterial activity (over 90 %), long-term color stability, biocompatibility, and biodegradability. In freshness monitoring trial, CS/Fe-HIA films were proved to be effective in real-time and visual monitoring of prawn spoilage. This study presents a new strategy for creating advanced biopolymer-based antimicrobial and colorimetric ammonia-sensitive film, boosting related application in smart active food packaging.