Butylated hydroxytoluene (BHT) emitted by fungi naturally occurring in olives during their pre-processing storage for improving olive oil stability

Extra virgin olive oil is widely consumed because of its nutritional benefits and sensory properties which are very important to be preserved in the product. Therefore, chemically synthesised compounds, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), are widely used as antioxidants in oil products. It is well known that the activity of some micro-organisms able to oxidise free fatty acids can lead to the loss of the stability of the final product. Nevertheless, several researchers have been recently motivated to evaluate the potential of micro-organisms on the production of bioactive compounds. In this paper, headspace solid micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were used for the characterization and investigation of Fungal Organic Volatile Metabolites (FOVCs) emitted by 14 fungal strains isolated from olives during their pre-processing storage. A wide range of volatile compounds were detected among them, BHT was produced at levels ranging between 0.3 and 13.1%. This compound could be considered for the industry as natural antioxidant to substitute the synthetic ones used for ameliorating the stability of olive oil and other fatty food products.