Antimicrobial Activity of Zeolite/Zinc Oxide Nanocomposite Containing Aloe Vera Gel Against Shigella spp. and Its Durability Effects on Strawberries

Nanomaterials are novel applicable tools to improve fruit quality by using antimicrobial agents to prolong food storage as well as contamination reduction. The objective of this study was to evaluate the cytotoxicity and antibacterial effect of zeolite/zinc oxide nanocomposite (Zeo/ZnONC) alone and with aloe vera gel (Zeo/ZnONC-AG) on Shigella sonnei and Shigella flexneri and its effect on the durability of strawberries. First, ZnO materials were characterized with X-ray fluorescence (XRF), and Zeo/ZnONC was evaluated with field emission scanning electron microscopy (FE-SEM) analyses to confirm ZnO nanoparticle formation. Subsequently, the minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) of Zeo/ZnONC and Zeo/ZnONC-AG against S. sonnei and S. flexneri were assessed. The preservative application of hydrogel nanocomposite on the quality of strawberries was evaluated through the appearance of the fruits and the growth of mildew colonies. The MIC and MBC values of Zeo/ZnONC-AG against S. sonnei and S. flexneri were lower than the Zeo/ZnONC in equal concentrations of ZnO (1 mg/ml up to 8 mg/ml). The growth of mold on the surface of strawberries treated with Zeo/ZnONC-AG has shown a delay with the increase of ZnO concentration at refrigerator temperature. In conclusion, this study exhibited that Zeo/ZnONC-AG preservative has noticeable benefits in control of contamination and durability enhancement of the fruits like strawberries. The potential application of nanomaterials in industrial food suggests more evaluation on this compound by further studies.