Volatile compounds produced by fungi grown in strawberry jam

Fungi are most important micro-organisms spoiling jams and other fruit preserves. The volatile compounds produced by fungi can be used to detect fungal growth in food. The aim of this study was to identify volatile organic compounds indicating fungal growth in strawberry jam. Ten fungal strains isolated from jam, yogurt or indoor air were grown in strawberry jam and strawberry jam agar. The volatile compounds produced by fungi were separated, identified and quantified using gas chromatography and mass spectrometry. The most commonly produced volatile metabolites were 2-pentanone (produced by ten strains), 3-methyl-1-butanol (nine strains), 1,3-pentadiene (eight strains), ethanol (eight strains) and styrene (seven strains). From 17 to 5200 ng of these compounds were measured per g of moldy strawberry jam agar already after 2 days incubation. The results indicate that volatile fungal metabolites identified in this study could be used to detect fungal contamination of jam.