No abstract

Guava is a fruit that presents a high degree of perishability. 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 shelf life of this fruit. Therefore, the objective 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 activity against phytopathogenic fungi, being able to inhibit or slow down the growth of phytopathogens Colletotrichum gloeosporioides, Puccinia psidii , Diaporthe spp, and Penicillium spp. Nondestructive (visual and weight loss) and destructive (firmness, titratable acidity, 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.