Uncovering the antifungal components from turmeric (Curcuma longa L.) essential oil as Aspergillus flavus fumigants by partial least squares†
Highly efficient and eco-friendly antifungal fumigants are desirable in food and crop production. Although turmeric (Curcuma longa L.) essential oil is known to have a potent antifungal effect, the quality of whole essential oil can be unstable, leading to unreliable antifungal activities. The aim of the present study is to uncover the active individual compounds in turmeric essential oil that provide the antifungal properties using a convenient chemometric model. The Aspergillus flavus inhibition activities of essential oils derived from 24 batches of Curcuma longa L. were evaluated, with various fumigation concentrations from 50 μL to 500 μL essential oils per plate. Meanwhile, eighteen volatile compounds were identified by static headspace gas chromatography-mass spectrometry. To combine the antifungal activities and chemical profiles with the spectrum-effect relationship based on the partial least squares model, three volatile compounds (i.e., eucalyptol, beta-pinene and camphor) were identified and verified as the most potent antifungal compounds by their higher contribution factor to antifungal indexes. Thus, this research will provide a useful approach to screen bioactive compounds, and these three compounds are promising antifungal alternatives to conventional treatments for the control of A. flavus contamination.