Özet:

Fungal disease agents, which are the problem in stored products, are one of the important factors limiting the quality of post-harvest products. Dried peppers are very often infected by fungal pathogens that produce mycotoxins. Aspergillus niger, Alternaria alternata and Fusarium incarnatum are important fungal agents that can produce potential mycotoxins that cause disease in many plants in the pre- and post-harvest periods. The isothiocyanates (ITCs), produced by Brassica spp. and having broad antimicrobial activity, are allelochemical compounds with antimicrobial activities associated with the biologically active degradation products of glucosinolates. In this study, the in vitro antifungal effects of different isothiocyanate compounds such as methyl isothiocyanate (MITC), 2-propenyl (Allyl) isothiocyanate (AITC), benzyl isothiocyanate (BITC) and ethyl isothiocyanate (EITC) were investigated against Aspergillus niger, Alternaria alternata and Fusarium incarnatum isolates. Based on the minimum inhibition concentrations (MIC) that completely inhibit mycelial growth, the highest antifungal activity was displayed by MITC against Fusarium incarnatum, Aspergillus niger and Alternaria alternata at 0.06, 0.09 and 0.09 μl petri-1 concentrations, respectively. The lowest antifungal activities were shown by EITC against A. niger and F. incarnatum at 0.15 and 0.21 μl petri-1, and by AITC and BITC against A. alternata at the concentration of 0.21 μl petri-1. In addition, It has been determined that ITCs compounds generally have fungicidal effects at MIC values. The results showed that isothiocyanates, which have antifungal activity at very low concentrations, have the potential to be applied as a fumigant against fungal agents that cause spoilage in stored agricultural products.