Cyclodextrin-grafted nanoparticles as food preservative carriers

Abstract Photocatalytic properties of titanium dioxide nanoparticles (TiO2 NPs) have encouraged its use as filler in polymer-based nanocomposites with application in food packaging. The surface modification of TiO2 NPs with cyclodextrins (CDs), can improve their functionality in a large extent. Within this purpose, sorbic acid (SA) and benzoic acid (BA), commonly used as antifungal and antibacterial food preservatives, respectively, have been encapsulated in modified NPs. Inclusion complex formation of SA and BA with α and βCDs in water at 298.0 K has been studied first by means of 1H-NMR and UV-Vis spectroscopy to determine stoichiometry and affinity for the macrocycles. The loading efficiency of both preservatives in βCD-grafted NPs was found to be higher than those exhibited for αCD-NPs. In addition, preservative release kinetics from modified NPs have been carried out. In the case of SA delivery from αCD-grafted NPs, prolonged and sustained preservatives release profiles were observed, suggesting microbial growth inhibition if incorporated into packaging materials.