Inhibitory Effect of Green Onion on the Growth of Aspergillus parasiticus

This study was performed to investigate the inhibitory effect of green onion produced in Korea on the growth of A. parasiticus, a toxigenic strain. The effect was studied using different concentrations of freeze-dried green onion in solid culture with potato-dextrose agar (PDA) or in liquid culture with yeast-extract sucrose (YES) broth at 25°C for 15 days. The addition of green onion to the media showed inhibiting the fungal growth after three days of cultivation. The 1.0% concentration of green onion significantly reduced fungal diameter on PDA on the 3rd day, 6th day and 9th day, while 0.1%, 0.5% and 1.0% concentrations of green onion significantly reduced the mycelial weight on YES broth on the 9th day, 12th day and 15th day (p < 0.05). When inhibition of the fungal growth due to increasing the concentration of green onion was observed over time, remarkable effect was observed on the 9th day in the solid culture and on the 12th day in the liquid culture. As a result of addition of green onion, the fungal diameter on PDA was reduced by 4.6% ~ 11.5%, and mycelial weight on YES was reduced by 16.9% ~ 40.8% at those times. Dose-response relationships were observed between the concentration of green onion and inhibition of growth both in solid culture and in liquid culture during the incubation periods. This study indicates that a human consumption level of green onion produced in Korea could be an effective inhibitor of the growth of A. parasiticus.