Boswellia sacra essential oil: Antioxidant activity and antifungal effect on some spoilage fungi causing strawberry rot

In this study, the antifungal activity of Boswellia sacra essential oil was evaluated against fungi species causing strawberry rot (Botrytis cinerea, Aspergillus niger, and Rhizopus stolonifer), via well diffusion agar, disk diffusion agar, microdilution broth, and minimum fungicidal concentration methods. Extraction yield, total phenolic and flavonoid contents, and antioxidant activity (DPPH and ABTS radical scavenging methods) of the essential oil were also determined. The extraction yield of the oil was 1.30% w/w and its total phenolic and flavonoid contents were 69.37 mg GAE/g and 38.40 mg QE/g, respectively. The antioxidant activity of B. sacra essential oil, based on the DPPH- and ABTS-radical scavenging activity, were found to be 57.50% and 48.66%, respectively. According to the results of disk/well diffusion agar tests, B. cinerea and R. stolonifer were the most sensitive (the highest inhibition zone) and resistant (the lowest inhibition zone) fungal species to the B. sacra essential oil, respectively. The minimum inhibitory concentration and minimum fungicidal concentration were, respectively, ranged from 25-50 and 200-400 mg/ml. Based on the results, the B. sacra essential oil contains bioactive compounds with appropriate antioxidant and antimicrobial properties, and it could be therefore used as a natural preservative agent to increase the shelf-life of various food products.