Edible Chitosan/Propolis Coatings and Their Effect on Ripening, Development of Aspergillus flavus, and Sensory Quality in Fig Fruit, during Controlled Storage

Biodegradable alternatives for the control of Aspergillus flavus in fig fruit were tested with the application of coatings based on chitosan (CS) and propolis (P). To potentiate the fungicidal effect, nanoparticles of these two (CSNPs and PNPs) were also considered. The objectives of this research were to evaluate the effect of different formulations on: (a) the ripening process of the fig, (b) the incidence of A. flavus and the production of aflatoxins, and (c) the acceptance of the treated fruit by a panel. The nanostructured coatings did not influence the ripening process of the fruit during the 12 days of storage, however, the antioxidant activity increased by approximately 30% with the coating CS + PNPs + P. The figs treated with CS + CSNPs + PNPs + P, inhibited the growth of the fungus by about 20% to 30% under laboratory and semi-commercial conditions. For all treatments, the aflatoxin production was lower than 20 ppb compared to the control with values of c.a. 250 ppb. The sensory quality was acceptable among the panel. The edible coatings can be a non-toxic alternative for post-harvest preservation and the consumption of fig fruit. The next step will be its inclusion and evaluation at a commercial level in packing houses.

Automated summary

The study tested biodegradable alternatives for controlling Aspergillus flavus in fig fruit using coatings based on chitosan and propolis, as well as their nanoparticles. It was found that these coatings did not affect the ripening process of the fruit, but increased antioxidant activity and inhibited fungal growth, leading to lower aflatoxin production. The coatings were also found to be acceptable in terms of sensory quality, indicating their potential as a non-toxic alternative for post-harvest preservation and consumption of fig fruit. Further evaluation at a commercial level will be the next step.