Essential ginger oil has antifungal action

By Maria Luiza De Grandi, journalist of Ciência Rural, Santa Maria, RS, Brazil and Miguel Machinski Junior, Department of Basic Health Sciences (DBS), Universidade Estadual do Maringá, Maringá, PR, Brazil

Fungi are microorganisms that can often contaminate products and foodstuffs with their toxins and this contamination causes significant losses in quality, quantity and nutritional profile. According to the United Nations Food and Agriculture Organization (FAO), approximately 25% of grains produced worldwide are contaminated by toxic chemical substances from fungi (BHAT; RAI; KARIM, 2010). In order to find natural and less toxic compounds to replace synthetic fungicides, researchers from Universidade Estadual do Maringá (UEM) in partnership with the Escola Superior de Agricultura Luiz de Queiroz of the Universidade de São Paulo (Esalq ‒ USP) analyzed the essential oil of ginger to evaluate its effectiveness in inhibiting the development of fungi in irradiated corn kernels. The article “Antifungal activity and inhibition of aflatoxins production by Zingiber officinale Roscoe essential oil against Aspergillus flavus in stored maize grains” was published in the journal Ciência Rural (vol. 50, no. 6).

Image: Brett Hondow.

Essential oils (OE) from plants can be an alternative to the use of synthetic chemicals due to their antifungal activity (FERREIRA et al., 2013; KOHIYAMA et al., 2015; NERILO et al., 2016). For the research, the essential oil of ginger (Zingiber officinale) was chosen because it has antifungal and antiaflatoxigenic properties. Ginger essential oil (GEO) was obtained by hydrodistillation, a variation of steam distillation, using a Clevenger apparatus. The resulting effects of essential oil on the analyzed corn kernels were compared to a synthetic antifungal agent (carbendazim + tiram), traditionally used for seed treatment.

The results, confirmed in a dose-dependent manner through the in situ test, showed antifungal efficacy of OEG against the fungus Aspergillus flavus. The essential oil of ginger inhibited the production of aflatoxins and controlled the growth of the fungus. “Ginger essential oil can be used as an effective and non-toxic alternative to conventional treatments on stored corn kernels for the natural control of A. flavus.”, Highlights researcher Miguel Machinski Junior. Taking into account that the essential oils themselves are oxidized and degraded by heat and light, the researcher adds that the use of oils through encapsulation and nanotechnology are also being analyzed.

References

BHAT, R., RAI, R.V. and KARIM, A.A. Mycotoxins in food and feed: present status and future concerns. Comprehensive Reviews in Food Science and Food Safety [online], 2010, vol. 9, no. 1, pp. 57-81, E-ISSN: 1541-4337 [viewed 24 August 2020]. DOI: 10.1111/j.1541-4337.2009.00094.x. Available from: https://onlinelibrary.wiley.com/doi/full/10.1111/j.1541-4337.2009.00094.x

FERREIRA, F.D., et al. Inhibitory effect of the essential oil of Curcuma longa L. and curcumin on aflatoxin production by Aspergillus flavus Link. Food Chemistry [online]. 2013, vol. 136, no. 2, pp. 789-793, ISSN: 0308-8146 [viewed 24 August 2020]. DOI: 10.1016/j.foodchem.2012.08.003. Available from: https://www.sciencedirect.com/science/article/pii/S0308814612012770?via%3Dihub

KOHIYAMA, C.Y., et al. Antifungal properties and inhibitory effects upon aflatoxin production of Thymus vulgaris L. by Aspergillus flavus Link. Food Chemistry [online]. 2015, vol. 173, pp. 1006-1010, ISSN: 0308-8146 [viewed 24 August 2020]. DOI: 10.1016/j.foodchem.2014.10.135. Available from: https://www.sciencedirect.com/science/article/pii/S0308814614017099?via%3Dihub

NERILO, S.B., et al. Antifungal properties and inhibitory effects upon aflatoxin production n by Zingiber officinale essential oil in Aspergillus flavus. International Journal of Food Science and Technology [online]. 2016, vol. 51, no. 2, pp. 286-292, e-ISSN: 1365-2621 [viewed 24 August 2020]. DOI: 10.1111/ijfs.12950. Available from: https://ifst.onlinelibrary.wiley.com/doi/abs/10.1111/ijfs.12950