Monitoring food freshness using a multilayer colorimetric sensor film

Date

2023-3-28

Author

Oktay, Cansu

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

504
views

199
downloads

Cite This

Foodborne diseases might result in serious health problems and correspondingly huge economic and social burdens. Thus, cost-effective and safe advanced sensing materials/schemes are still in great demand to ensure food safety, particularly through user-friendly and cost-effective smart packaging technologies. In this sense, biomaterials can be used safely in smart food packaging applications while improving the structural and physical properties of packaging materials. Multilayer intelligent freshness labels based on bacterial nanocellulose (BNC), polyvinyl alcohol (PVA), and anthocyanins doped zeolitic imidazolate framework-8 (GSE@ZIF-8) nanocrystals were fabricated in this study. BNC was used for the inner layer of the multilayer system to create a highly porous fibrous matrix, which facilitated the diffusion of the released gases as a result of spoilage to reach anthocyanin (GSE) encapsulated ZIF-8. The outer protective layer was fabricated from PVA to ensure optical transparency and provide a support layer for anthocyanins doped ZIF-8. First, optical, structural, thermal, and surface characterizations of GSE@ZIF-8 nanocrystals were carried out and the successful incorporation of anthocyanins into ZIF-8 nanocrystals was illustrated. Next, GSE@ZIF-8 was introduced into PVA, and multilayer films were fabricated by spincoating of PVA/GSE@ZIF-8 layers onto BNC. The influence of the deposition cycle numbers on the barrier, mechanical, thermal, morphological, and colorimetric properties of multilayer labels was examined. The ammonia sensing range and mechanical and barrier properties of the films were demonstrated to be controlled by the number of the PVA/GSE@ZIF-8 layers on the BNC. BNC-2PVA/GSE@ZIF-8 films showing the best colorimetric sensitivity towards volatile ammonia were tested with skinless chicken breasts to monitor the freshness. The changes in the ΔE and a* values of BNC-2PVA/GSE@ZIF-8 film were in line with the microbial growth and TVB-N release in food samples during 10 days of storage at 4 ⁰C. Taken together, the synthesized multilayer BNC-2PVA/GSE@ZIF-8 film can distinguish the fresh and spoiled chicken meat during storage at 4 ℃ without destructive testing.

Subject Keywords

Bacterial nanocellulose, ZIF-8, Anthocyanins, Spin coating, Intelligent food packaging

URI

https://hdl.handle.net/11511/103055

Collections

Graduate School of Natural and Applied Sciences, Thesis