Effect of Roasting Temperatures of Garlic, Shallot and Dried Chili on Antifungal Activity of Aspergillus niger

Abstract

This research was to study the effect of roasting temperatures of garlic (70 and 90°C for 10 min), shallot (70 and 90°C for 15 min), and dried chili (90°C for 25 min) extracted by petroleum ether on the antifungal activity of Aspergillus niger. The inhibition activities on mycelial growth by agar dilution method and spore germination by broth dilution method (BDM) were tested at the concentrations of 0.1, 0.5 and 1.0% (w/v). The minimum inhibitory concentration in spore germination (MIC) and minimum fungicidal concentration on spore germination (MFC) by BDM were also investigated. The results showed that an increase in roasting temperature decreased the inhibitory efficacy of garlic and shallot extracts on the mycelial growth and spore germination of A. niger. Whereas, the dried chili extract inhibited only the mycelial growth. The non-roasted dried chili showed a greater significant antifungal activity than the roasted dried chili. The non-roasted and roasted dried chili had the highest MIC (1.25% w/v) and MFC (5.0% w/v) as well as in roasted shallot at 90°C followed by roasted shallot at 70°C (MIC=0.312%, MFC=5.0%); non-roasted shallot and roasted garlic at 90°C (MIC=0.312%, MFC=1.25%); roasted garlic at 70°C (MIC=0.039%, MFC=0.312%); and non-roasted garlic (MIC=0.039%, MFC=0.078%), respectively.