Growth Inhibition of Aspergillus niger by Cinnamaldehyde and Eugenol

Abstract

Inhibitory effects of cinnamaldehyde and eugenol against Aspergillus niger, major spoilage mold of fruits and nuts, were investigated. A. niger inoculated on agar plates was exposed to paper discs impregnated with 10 μL of cinnamaldehyde and eugenol at various concentrations (10 - 100 mg/ml) before incubating at 25 °C for 3 days. Antifungal activities of cinnamaldehyde and eugenol at the minimum inhibitory concentration (MIC) were examined at various temperatures ranging from 20 °C to 37 °C. The MIC against A. niger for cinnamaldehyde and eugenol was 40 μg/mL and 100 μg/mL, respectively. Cinnamaldehyde and eugenol at the MIC completely inhibited A. niger up to 14 days within the range of temperature studied. The percentages of mycelium growth inhibition of cinnamaldehyde and eugenol were still higher than 80 % after incubating for 21 and 28 days at all conditions examined. Cinnamaldehyde and eugenol showed good potential as natural antimicrobial additives to inhibit growth of A. niger in stored fruits and nuts.

Keywords

• Growth inhibition
• Aspergillus niger
• cinnamaldehyde
• eugenol