Gum arabic/guar gum based biopolymeric nanohydrogel for shelf-life enhancement of grapes and photocatalytic dye reduction

Recently, natural food preservation systems composed of metal oxide nanoparticles (NPs) gained great attention from the food manufacturers, however, toxicity of NPs is a major concern. Therefore, in this study we synthesized multifunctional gum arabic/guar gum biopolymeric nanohydrogel embedded with NPs for the enhancement of the shelf-life of the grapes and for photocatalytic dye reduction. Copper, zinc, and iron metal oxide NPs were tailored using chemical precipitation and co-precipitation methods and subjected to various characterization processes. The smaller particle size was observed with iron oxide NPs (23.64 nm) as compared to other NPs (Cu and Zn). All metal oxide NPs showed cell viability ranging from 90.73 – 99.94%. The average droplet size of the formulated hydrogel samples was ranging from 240.6 to 345.8 nm with an irregular and rough morphology. Nanohydrogels at varied concentrations embedded with metal oxide NPs showed cell viability in the range of 93.73–99.97%. Zinc metal oxide NPs embedded in hydrogel showed higher spreadability properties, while hydrogel embedded with iron oxide NPs showed lower spreadability properties. Grapes coated with formulated hydrogel did not affect the physicochemical attributes during the storage (10 days), hence it can be scaled up as an effective natural preservation system.