Antifungal Activity of Lemongrass Essential Oil

Prévia do material em texto

Critique Paper on 
“Antifungal Activity of Lemongrass (Cympopogon citratus L.) Essential Oil 
Against Key Postharvest Pathogens” 
 
Diseases, which are produced by a variety of plant pathogenic organisms, are a dominant 
contributor of crop and plant damage. Hence, fungi are the leading cause of crop loss around the 
world (McGrath, 2004). Pesticides have a range of negative effects, including pesticide leftovers 
on food, handling hazards, increased expense, and a danger to the environment and human health 
(Paster & Bullerman, 1988). 
In the research article “Antifungal Activity of Lemongrass (Cympopogon citratus L.) 
Essential Oil Against Key Postharvest Pathogens,” Tzortzakis & Economakis (2007) tested the 
efficacy of lemongrass oil against postharvest infections, with a focus on the essential oil's 
potential future application as an anti mould agent. The research presented a significant results 
showing that the use of lemongrass oil-enrichment reduced the subsequent colony development of 
the postharvest pathogens. Hence, the lemongrass oil-enrichment can be an alternative for 
synthetic fungicides or other sanitation treatments used in preservation and manufacturing. 
 Tzortzakis & Economakis (2007) used pure lemongrass essential oil and tested its 
antifungal property against Colletotrichum coccodes, Botrytis cinerea, Cladosporium herbarum, 
Rhizopus stolonifer and Aspergillus niger in vitro. The researchers isolated the postharvest 
pathogens from a tomato fruit the sub-cultured on standard triple-vented Petri dishes containing 
20 ml of Potato Dextrose Agar. They tested the antifungal activity on the fungal colony 
development through dilution method in different ppm (parts per million) of essential oil. Using 
Analysis of Variance (ANOVA) and Duncan's Multiple Range test (P= 0.05) following one-way 
ANOVA, Tzortzakis & Economakis (2007) found that the addition of lemongrass oil to PDA 
media culture resulted in a significant (Pb ˂ 0.05) reduction in colony development, fungal 
sporulation, and spore germination. 
 The researchers’ assessments and evaluations had a significant value in food industry as 
fungi are the leading cause of crop loss around the world. They involved various postharvest 
pathogens to test the effectivity of the lemongrass essential oil thus, supporting it with the past 
studies of lemongrass antifungal activities. The materials and methods performed in the study were 
detailed and properly executed such as storing the isolates (postharvest pathogens) and the cultured 
dishes in a specific room temperature which can be also a factor of producing unreliable results if 
not performed. Significant results were acclaimed in the results of the study, hence, the findings 
were analysed and explained briefly. They also included previous studies that supported their 
findings as well as studies that some postharvest pathogens were not affected when treated with 
lemon grass oil in a culture medium such as F. verticillioides as reported in the past studies of 
Adegoke & Adesola (1996) indicating that not all postharvest pathogens can be treated with 
lemongrass essential oil. Moreover, contrasting the present findings varied when evaluated in other 
infections, most likely due to differences in the treatment and/or pathogen itself. 
 The study proves that oil essentials can possess antifungal activity and may aid in food 
preservation. This study supports to exploitation as an ideal therapeutic intervention for future 
plant disease control programs eliminating fungal spread. Moreover, essential oils are natural 
products obtained from plants that can be utilized as natural additives in a variety of foods due to 
their antifungal, antioxidant, antibacterial, and anti-carcinogenic characteristics in which could 
help the environment and drawbacks of using synthetic preservatives on human health as one of 
the problems stated in the study. Hence, using natural preservatives are less likely to cause allergic 
reactions and long-term health effects. 
As the general population more aware of these dangers, there is a greater need to develop 
better pesticide alternatives. Natural plant preservatives with pesticidal efficacy are one such 
possibility, as they have low toxicity, minimal economic and environmental consequences, and 
massive public acceptance. Tzortzakis & Economakis (2007) gave an important study promoting 
the use of natural preservatives of foods as an innovative, useful aid, and alternative for synthetic 
fungicides or other sanitation treatments used in preservation and manufacturing. By lowering the 
spore production in the processing atmospheric conditions and using essential oil as an alternative 
food preservative, oil enrichment may diminish disease development with a large contribution to 
reducing the transmission of pathogens. 
The study can be replicated for future research by using other postharvest pathogens and 
higher concentrations of essential oils. Moreover, evaluation and testing of the minimum 
concentration on application of fungicides to meet the full extent of effectiveness without affecting 
the fresh quality of the goods and its storage. 
 
REFERENCE 
Tzortzakis & Economakis (2007). Antifungal activity of lemongrass (Cympopogon citratus 
L.) essential oil against key postharvest pathogens. Innovative Food Science & Emerging 
Technologies, 8(2), Pages 253-258. 
McGrath, M.T. (2004). What are Fungicides. The Plant Health Instructor. Retrieved from 
https://www.apsnet.org/edcenter/disimpactmngmnt/topc/Pages/Fungicides.aspx