Alginate-Based Zinc Oxide Nanoparticles Coating Extends Storage Life and Maintains Quality Parameters of Mango Fruits “cv. Kiett”

In this study, we describe the synthesis of zinc oxide nanoparticles (ZnO NPs) and evaluate the impact of alginate-based ZnO NPs (Alg–ZnO NPs) on microbiological activity, storage behavior, and physico-chemical properties of ‘Kiett’ mango fruit. The fruits were coated with alginate and Alg–ZnO NPs and then stored at 13 °C; uncoated mango fruits were used as controls. ZnO NPs were synthesized and characterized, confirming the formation of spherically shaped particles with sizes ranging from 12 to 15.1 nm and a zeta potential equal to 31 mV. Alg–ZnO NPs exhibited the same inhibition capacities against the growth of E. coli and S. aureus bacteria. The cold-stored fruits showed an increase in weight loss, respiration rate, total soluble solids (TSS), total sugars, and total carotenoids over the storage period. However, this increase was comparatively less significant in coated fruits than in uncoated ones. Alg–ZnO NP treatment maintained better fruit quality, controlled the decay incidence, and increased the shelf life of the mango fruits. Firmness and titratable acidity (TA) significantly decreased during storage, but this decrease was reduced in coated fruits. We conclude that Alg–ZnO NP treatment could be a promising safe alternative for maintaining fruit quality, extending the storage period, and increasing the shelf life of mango fruits ‘cv. Kiett’.