Potential evaluation of volatile organic compounds produced by Wickerhamomyces subpelliculosus and Saccharomyces cerevisiae as bio-fumigants for controlling Aspergillus flavus spoilage and aflatoxin contamination in dates

Abstract

This study evaluated the antifungal and anti-aflatoxigenic potential of volatile organic compounds (VOCs) produced by Wickerhamomyces subpelliculosus Y7, Saccharomyces cerevisiae X19G2, and their combined culture (Y7–X19G2) as biofumigants to protect stored date fruits from contamination by the aflatoxigenic fungus Aspergillus flavus. Ethyl acetate and ethanol were the major VOCs produced by Y7 and X19G2, respectively. Notably, co-culturing Y7 and X19G2 enhanced ethyl acetate production while reducing ethanol levels. VOCs from both individual strains and their combination significantly suppressed A. flavus mycelial growth and sporulation by up to 47 % and 95 %, respectively and completely inhibited aflatoxins B1 and B2 (AFB1 and AFB2) in vitro. Bio-fumigation of dates with VOCs from Y7, X19G2, and Y7–X19G2 effectively controlled A. flavus growth on dates, achieving more than 99.6 % inhibition. Moreover, AFB1 and AFB2 production was fully suppressed by X19G2 and Y7–X19G2 VOCs, while Y7 VOCs alone reduced AFB1 and AFB2 by 97 % and 87.8 %, respectively. These findings, along with the complete absence of sensory quality deterioration in dates, demonstrate the strong potential of VOCs from W. subpelliculosus, S. cerevisiae, and their co-culture as eco-friendly biofumigants to mitigate aflatoxin contamination in stored dates.