Carvacrol nanocapsules as a new antifungal strategy: Characterization and evaluation against fungi important for grape quality and to control the synthesis of ochratoxins

• Published in: International journal of food microbiology 2024-05, Vol.416, p.110659-110659, Article 110659
• Main Authors: Tópor, Athos, Veras, Flávio Fonseca, Cacciatore, Fabiola Ayres, Silveira, Rafaela Diogo, da Silva Malheiros, Patrícia, Welke, Juliane Elisa
• Format: Article
• Language: English
• Subjects: Antifungal; Antifungal Agents - metabolism; Aspergillus carbonarius; Aspergillus flavus; Aspergillus niger; Botrytis cinerea; Cymenes; Ecosystem; Encapsulation; Humans; Mycotoxins - analysis; Nanocapsules; Ochratoxins; Polymethacrylic Acids; Vitis - microbiology
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2024.110659

Fungi are a problem for viticulture as they can lead to deterioration of grapes and mycotoxins production. Despite the widespread use of synthetic fungicides to control fungi, their impact on the agricultural ecosystem and human health demand safer and eco-friendly alternatives. This study aimed to produce, characterize and assess the antifungal activity of carvacrol loaded in nanocapsules of Eudragit® and chia mucilage as strategy for controlling Botrytis cinerea, Aspergillus flavus, Aspergillus carbonarius, and Aspergillus niger. Eudragit® and chia mucilage were suitable wall materials, as both favored the encapsulation of carvacrol into nanometric diameter particles. Fourier Transform Infrared Spectroscopy (FTIR) analysis suggested a successful incorporation of carvacrol into both nanocapsules, which was confirmed by presenting a good encapsulation efficiency and loading capacity. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) analyses revealed adequate thermal resistance. All fungi were sensible to carvacrol treatments and B. cinerea was the most sensitive compared to the Aspergillus species. Lower concentrations of encapsulated carvacrol than the unencapsulated form were required to inhibit fungi in the in vitro and grape assays. Additionally, lower levels of carvacrol (unencapsulated or encapsulated) were used to inhibit fungal growth and ochratoxin synthesis on undamaged grapes in comparison to those superficially damaged, highlighting the importance of management practices designed to preserve berry integrity during cultivation, storage or commercialization. When sublethal doses of carvacrol were used, the growth of A. niger and A. carbonarius was suppressed by at least 45 %, and ochratoxins were not found. The nanoencapsulation of carvacrol using Eudragit® and chia mucilage has proven to be an alternative to mitigate the problems with fungi and mycotoxins faced by the grape and wine sector. •Nanoencapsulated carvacrol proved to be a promising strategy for fungal control.•Botrytis cinerea was the most sensitive fungus to different carvacrol treatments.•Aspergillus spp. growth in grapes was inhibited by carvacrol treatments.•Encapsulated carvacrol showed higher antifungal potential than the unencapsulated.•Ochratoxins were suppressed even when sublethal doses of carvacrol were used.