Volatilome Profiling of Mycotoxigenic Fungi Aspergillus carbonarius and Penicillium verrucosum in Mono‐ and Coculture With Saccharomyces cerevisiae

Volatile organic compounds (VOCs) emitted by fungi during growth may be used as an indicator for the detection of fungal contamination in foods, potentially preceding the development of visible fungal growth. In this study, the VOC profile of two ochratoxin A (OTA)‐producing fungi, Aspergillus carbonarius and Penicillium verrucosum , grown as monoculture and in coculture with Saccharomyces cerevisiae was elucidated, and the potential use of the VOCs fingerprint to distinguish among the three microorganisms was explored. The microorganisms were cultivated on Czapek Yeast Agar (CYA), and their VOCs were measured by gas chromatography–mass spectrometry (GC‐MS) at selected time points (3, 5, and 7 days) after inoculation using solid‐phase microextraction (SPME). Overall, 137 VOCs were detected, including ketones, aldehydes, alcohols, esters, organic acids, hydrocarbons, and terpenoids. For S. cerevisiae , 14 VOCs were identified as important for differentiation, including isoamyl acetate, isobutyl acetate, propyl acetate, 2‐phenylethyl butyrate, ethyl benzeneacetate, ethyl butanoate, ethyl undecanoate, 3‐methylbutanoic acid, 2‐methylpropanoic acid, acetic acid, butanoic acid, 3‐(methylthio)‐1‐propanol, farnesol, and citronellol. Four VOCs emerged as potential biomarkers for A. carbonarius ( β ‐himachalene, cis ‐thujopsene, ( R )‐cuparene, and δ ‐cuprenene), whereas all VOCs correlated with P. verrucosum were highly correlated with S. cerevisiae . These findings highlight that VOCs emitted by filamentous fungi and yeast during growth, combined with multivariate analysis, could be effectively used as a distinct fingerprint for discriminating between different microorganisms, especially in monoculture. However, in the case of the coculture of the two filamentous fungi with the yeast, partial discrimination could be achieved, compared to the respective monoculture.