Photothermal functionalized antibacterial packaging film with controllable release capability for fruit preservation

Area of Science:

• Materials Science
• Food Science
• Biotechnology

Background:

• Traditional active packaging films face limitations due to environmental conditions.
• Developing intelligent, contactless release systems for sustained food preservation remains a challenge.

Purpose of the Study:

• To fabricate a light-responsive, thermal-controlled active packaging film for intelligent food preservation.
• To evaluate the film's properties, including visual appearance, transmittance, mechanical strength, barrier performance, and photothermal activity.

Main Methods:

• Chitosan was integrated with copper molybdate (Cu-MoO _x ) and curcumin to create the CS/CMC film.
• The film's structural integrity, thermal stability, visual identifiability, light transmittance, mechanical properties, and barrier performance were assessed.
• Photothermal performance, stability, and synergistic antibacterial activity under near-infrared (NIR) irradiation were investigated.

Main Results:

• The CS/CMC film demonstrated excellent visual identifiability, good light transmittance, enhanced mechanical properties, and superior barrier performance against UV light and water vapor.
• The film exhibited effective photothermal conversion and stability upon NIR irradiation.
• Synergistic antibacterial activity against *E. coli*, *S. aureus*, *P. italicum*, and *P. expansum* was achieved, with rates up to 99.33% under NIR irradiation.
• Tangerines packaged with CS/CMC film showed extended shelf life and reduced nutrient loss compared to polyethylene packaging.

Conclusions:

• The developed light-responsive, thermal-controlled packaging film offers an intelligent and contactless approach to active food preservation.
• The CS/CMC film shows significant potential for enhancing food safety and extending shelf life through synergistic antimicrobial action and controlled release.