Study of thymol bioformulations with potential phytosanitary application

The essential oil (EO) of thyme ( Thymus vulgaris ) has antifungal and antimicrobial properties. Its high concentration of terpenes, such as thymol, makes it highly effective as a fungicide, particularly against fungi such as Moniliophthora roreri , a cocoa pathogen. However, the potential application as an organic fungicide is limited by the photostability and volatility of essential oils. Thus, the use of carriers for the extract has been the objective of this research. In this study, the adsorption-desorption process of thymol was evaluated in calcium alginate-bentonite microcapsules and the bentonite-chitosan composite as EO carriers. The results have shown that the maximum adsorption capacity was higher for the microcapsules than for the organoclays. However, the desorption percentages indicated that organoclays showed the most adequate release. Finally, the water activity values generated by both bioformulations were below 0.6, indicating that carriers can reduce the probability of microbial growth.