Efficiency of Novel Antimicrobial Coating Based on Iron Nanoparticles for Dairy Products’ Packaging

Abstract

The main function of food packaging is to maintain food's quality and safety. The use of active packaging, including antimicrobial materials, can significantly extend the shelf life of food. Many of these packaging solutions are based on the application of polymer films containing metal nanoparticles (e.g., Ag, Au, Cu) or metal oxides (e.g., TiO 2 , ZnO, MgO). However, the use of iron nanoparticles is rarely mentioned. In the study, polylactide (PLA) films containing zero-valent iron (ZVI) were made by casting method. Pure PLA films and PLA films with the addition of Fe 2 O 3 were used as comparative materials. The composition and structure of ZVI/PLA films were evaluated with scanning electron microscopy. The XRD spectra performed on ZVI/PLA films confirmed the presence of iron in the packaging material and revealed their oxide form (Fe 2 O 3 ). The addition of zero-valent iron in the concentration 1%, 3%, or 5% resulted in the formation of crystallographic planes measuring 40.8, 33.6, and 28.6 nm, respectively. The color and gloss of the films, and their antimicrobial activity against bacteria (Bacillus subtilis, Escherichia coli, Staphylococcus epidermidis) and fungi (Geotrichum candidum, Rhodotorula rubra) were also examined. The PLA films with addition of 3% of ZVI (w/w) inhibited the growth of all tested organisms in contrast to PLA and PLA/Fe 2 O 3 films. The addition of ZVI to polymer matrix caused changes in its appearance and optical properties. The ZVI/PLA coating used on polyolefin film allowed to extend the shelf life of goat cheese packed in examined material to 6 weeks. Considering the antimicrobial properties of the ZVI/PLA films and PLA biodegradability the obtained material can be successfully applied in the food industry.

The Effect of Zero-Valent Iron Nanoparticles (nZVI) on Bacteriophages

“…This was done to speed up the analysis and avoid unwanted oxidation of pristine ZVI. The sub-100 nm size of ZVI obtained by us was proved previously using SEM [ 45 ] and via Sherrer’s equation [ 48 ]. Both pristine and oxidized ZVI nanoparticles were similar in size and shape, but oxidation changed the surface features of the studied material.…”

Application of Iron Nanoparticle-Based Materials in the Food Industry

“…Iron nanoparticles can be used to address food oxidation by applying antimicrobial coatings to the inner surface of the packaging. Such a coating gradually releases the antimicrobial substances, or they are immobilized on the active surface of the packaging [ 86 ]. Song et al [ 87 ] produced composites of polydopamine with iron oxide nanoparticles (IONPs@pDA).…”

“…The therapeutic effect on iron deficiency occurs at doses of 3 mg to 6 mg per kilogram of body weight per day. Exceeding the recommended standard (10–20 mg/kg body weight) causes adverse effects [ 86 ]. One of the potential mechanisms of IONPs is to inhibit intracellular ROS and reduce peroxidative damage [ 174 ].…”

Pengaruh Proses Pembekuan Daging Kelapa (Cocos nucifera L.) Terhadap Karakteristik Produk Kelapa Parut Kering

“…Berdasarkan Gambar 2, rata-rata nilai ΔE berkisar pada 2.08-3.30. ΔE dengan nilai diantara 2 dan 3.5 menggambarkan bahwa perubahan warna pada produk sebelum dan sesudah proses pengeringan dapat disadari oleh pengamat yang tidak berpengalaman[22]. Rata-rata nilai ΔE terbesar terdapat pada kelapa parut kering hasil pembekuan dan kondisi pengeringan P2 dengan nilai ΔE sebesar 3.3.…”