Investigating the antifungal effects of essential oils on Aspergillus sp. in strawberry (Fragaria ananassa Duchesne) fruit

Abstract

The growing attention and interest in alternatives for chemical preservatives with natural types has led to numerous studies on essential oils and plant extracts. Strawberries, due to their high respiration and metabolic activity, and high water content, are highly sensitive to microbial contamination. Research Method: An experiment was conducted to investigate the effect of the essential oils of some medicinal plants on the fungus Aspergillus sp. in strawberry fruit in in vivo and in vitro conditions as a factorial form in a completely randomized design with three replications. The first factor included the type of essential oil: frankincense, ginger, cinnamon, and tarragon essential oils, and the second factor included the concentration of essential oil at five levels (0, 200, 400, 600, and 800 μL.L-1). Findings: In vitro results showed that with the increase in the concentration of plant essential oils, their antifungal activity increases. As a result, the lowest fungus colony diameter was obtained from the concentration of 800 μL.L-1 of essential oil. A comparison of the average type of essential oil showed that cinnamon essential oil had more antifungal activity than other essential oils used, so that at any level (200 to 800 μL.L-1), it caused a 100% inhibition of Aspergillus sp. growth. In vivo, results showed that the best appearance of the fruit and the highest soluble solids were recorded from the concentration of 800 μL.L-1 of essential oil. Cinnamon essential oil treatment resulted in the best fruit appearance, the highest soluble solids, and the highest levels of antioxidants, anthocyanin, and sugar compared to frankincense essential oil. Research limitations: There were no limitations. Originality/Value: Among the essential oils, cinnamon essential oil showed better antifungal activity against Aspergillus sp., which causes strawberry fruit spoilage. Therefore, it can be used as a substitute for chemical fungicides, although other essential oils may also be effective.