Nanoemulsion of oregano essential oil as natural controller of potato common scab

PRIETO, M.C.; GROSSO N. R.; ASENSIO C.; LUCINI, E. I.

Chicago

Congreso; IFT Annual Meeting - 2018; 2018

Institute of Food Technologists

IntroductionPotatoes are considered the fourth food for world nutrition. Potato common scab (PCS) is a worldwide disease that seriously affects potato crops reducing the quality of the product and causing large economic losses. The main agent for PCS is Streptomyces scabiei, a filamentous Gram-positive bacteria. At present, an effective method to control it has not been found. An alternative method based on essential oils (EOs) could be appropriate. Oregano EO has been recognized for its antibacterial properties. However, the EOs are susceptible to degradation by heat, light and oxygen. The inclusion of EOs into nanoemulsions (NEs) could be alternative to protect them and to deliver them, gradually. The objective of this work was to evaluate oregano EO and EO-NE antibacterial properties against S. scabiei.MethodLeaves and flowers of oregano were hydro-distilled in a clevenger-type apparatus. EO chemical composition was analyzed by GC/MS. A nanoemulsion with a concentration of 160 mg/mL of oregano EO was prepared. Micro-dilution assay was used to determinate the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of oregano EO and EO-NE of two strains of S. scabiei.SignificanceEOs are recognized by their antimicrobial properties. The use of EOs and their nanoemulsions to control PCS constitute a solution to preserve potatoes quality using a natural agent. ResultsThe major compounds of oregano EO were trans-sabinene hydrate (19.19%), thymol (18.33%), ɣ-terpinene (12.68%), orto-cymene (7.45%) and 4-terpineol (6.17%). The MIC of pure EO and EO-NE were 0.286 and 1.266 g/L (0.4 g EO/L) in both strains, respectively. The MBC of pure EO and EO-NE were 1.14 and 2.532 g/L (0.4 g EO/L) in both strains, respectively. NE-EO result more efficient to control PCS in comparison with pure oregano EO. These results indicate that the use of oregano EO and its NE can be used as a control agent for PCS to improve potatoes quality.