Copper crosslinked chitin nanocrystals as antifungal coating ingredients

Overview

Copper crosslinked chitin nanocrystals (Cu-Chitin NPs) are a novel nanomaterial engineered to serve as an active antifungal ingredient in coatings. The technology addresses the persistent challenge of mold and fungal contamination on food-contact surfaces and fresh produce, which causes significant post-harvest losses and food safety concerns.

The key differentiator is safety: every ingredient used in the synthesis of Cu-Chitin NPs is approved by the U.S. Food and Drug Administration as Generally Recognized As Safe (GRAS). This positions the material as a strong candidate for applications in food packaging, agricultural coatings, and other settings where regulatory approval and consumer safety are critical.

Technical specifications

Synthesis and composition:

• Cu-Chitin NPs are produced using a method developed by the research team that relies exclusively on GRAS-approved ingredients
• The material combines chitin nanocrystals with copper ions via a crosslinking approach, producing stable nanoparticles with antimicrobial functionality

Validated antibacterial performance:

• Demonstrated activity against both Gram-positive and Gram-negative bacteria, tested using E. coli and Listeria monocytogenes
• At 0.2 mg/mL, Listeria monocytogenes colony counts decreased by 1.8 log CFU after 16 hours
• At 0.1 mg/mL, Listeria monocytogenes colony counts decreased by 0.7 log CFU after 16 hours
• Treated groups showed statistically significant inhibition compared to controls (p<0.05)

Planned antifungal testing:

• Agar diffusion assays against Botrytis cinerea (B. cinerea), a common plant pathogen
• Coating performance evaluation on stainless steel, PET, and glass surfaces
• Spray application testing on strawberries, tomatoes, and cantaloupe to measure growth curves and physiological indicators related to plant mildew

Technology readiness level

The Cu-Chitin NP synthesis process has been established and the material has demonstrated clear antibacterial efficacy in laboratory testing. Antifungal validation, which is the central focus of the proposed next phase, has not yet been completed. Planned studies include agar diffusion tests against B. cinerea on multiple surface materials and direct spray trials on fresh produce. The technology is currently at an early-to-mid stage of development, with laboratory proof-of-concept established for antibacterial activity and antifungal performance yet to be demonstrated. Further work is needed to confirm efficacy, optimize formulations, and advance toward commercial readiness.