Essential oil microencapsulation technology to provide peanut seeds protection against fungal pathogens

GIRARDI, N.S.; PASSONE, M.A.; GARCÍA, D.; NESCI, A.; ETCHEVERRY, M.

Agricultural Research Updates Volume 21

Nova Science Publishers

Año: 2017; p. 213 - 242

The Argentinean peanut (Arachis hypogaea) is known worldwide for its quality. As consequence of the particular growth of peanut seeds (hypogeo) and their consecutive monoculture, the prevalence of fungal pathogen infections continues to increase. Therefore, postharvest peanut seeds contain mycelia and spores of pathogenic fungi, which can result in a significant decrease in grain quality during storage. Fungicides are applied at pre-seedling time, while during peanut storage period of about 4-5 months (from harvest to planting), seeds do not receive any treatment. In an attempt to find eco-friendly alternatives, a screening of 96 plant extracts was carried out being the fumigant phase application of nontoxic boldo (Peumus boldus) and poleo (Lippia turbinata) the promising essential oils (EOs) to control spoilage fungi of peanuts. The aim of this chapter is summarize the results obtained from the application of microencapsulated essential oils previously selected in our lab, evaluating the effect of these formulations on fungal levels in stored peanut intended for seed. Characterization of microencapsulated EOs and abiotic external factors influence (time, temperature and water activity) on their release properties are discussed in this chapter. Comparisons of antifungal effects at in vitro and in situ assays of boldo and poleo oils are also analyzed. Furthermore, an analysis on how the stress factors derived from the presence of EOs, synthetic fungicide and the peanut aw modifications affect the seed germination power is developed. Finally, the residual levels in the substrate of the most effective EO are also covered in the present chapter.