Tara Gum Coating with Embedded ZnO Nanostructures for Increased Postharvest Guava Shelf Life

Guava is a fruit that presents a high degree of perishabi l i t y . This problem requires new effective technology with low environmental and human health impact for its resolution. A coating of tara gum with ZnO nanostructures is a promising alternative to increase the shel f life of this fruit. Therefore, the objec t i v e of this work was to optimize the production of the nanostructure, characterize it, and apply it in a guava coating. The nanostructure had a size of 173.15 nm and a polydispersity index of 0.601. Transmission electronic microscopy (TEM) confirmed a spherical morphology. ZnO nano showed antimicrobial act i v i t y against phytopathogenic fungi, being able to inhibit or slow down the gro w t h of phytopathogens Colletotrichum gloeosporioides, Puccinia psidii, Diaporthe spp, and Penicillium spp. Nondestructive (visual and weight loss) and destructive (firmness, titratable acidi t y , pH, total solid residues, reducing sugars, and soluble sugars) tests were performed on guavas and showed very little change over 16 days post-harvest. The coating with ZnO nano resulted in better physical-chemical properties, and it verifies the potential use of the packaging produced for postharvest guava fruit conservation.

Automated summary

This study investigates the potential use of ZnO nanostructures and tara gum coating to prolong the shelf life of guava fruit. The results show that ZnO nanostructures exhibit antimicrobial activity and maintain the visual and quality stability of guava for 16 days post-harvest. This research provides a potential packaging solution for the postharvest preservation of guava fruit.