Enhancing cinnamon essential oil activity by nanoparticle encapsulation to control seed pathogens

• Published in: Industrial crops and products 2018-11, Vol.124, p.755-764
• Main Authors: Bravo Cadena, Marimar, Preston, Gail M., Van der Hoorn, Renier A.L., Flanagan, Nicola A., Townley, Helen E., Thompson, Ian P.
• Format: Article
• Language: English
• Subjects: Alginate; Cinnamaldehyde; Crop protection; Essential oils; Mesoporous silica nanoparticles; Phytopathogens
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2018.08.043

[Display omitted] •Nanoparticle (NP) encapsulation of essential oils highly improves biocide activity.•Alginate seed coating with cinnamaldehyde-loaded NPs against bacterial infections.•Seed treatment increased symptomless plants by 143.58%.•NPs allow doses of essential oils up to 90,000-fold lower to be effective in planta. Natural biocides, such as cinnamon (Cinnamomum zeylanicum) bark essential oil, have enormous potential as antimicrobials but are limited by their volatility and rapid degradation. To counteract this and to prolong the efficacy of the biocide, cinnamaldehyde (CNAD, the main bioactive compound of cinnamon essential oil) was encapsulated into mesoporous silica nanoparticles (MSNPs). The synthesised CNAD-MSNPs can be used to tackle the issue of global crop loss; every year, more than 40% of global food production (estimated at $500 billion USD) is lost to diseases. This is despite the annual use of over two million tonnes of pesticides. To address seed borne diseases, CNAD-MSNPs were incorporated into a sodium alginate seed coating. As a proof of concept, this system was tested against Pseudomonas syringae pv. pisi, the causative agent of pea bacterial blight, and demonstrated to increase the number of symptomless plants by 143.58% twenty days after sowing. Additionally, the concentration of CNAD present in the alginate coating was estimated to be