Analysis of virgin olive oils volatilome: quality grade evaluation and study of modifications during storage

Virgin olive oil (VOO) is a cornerstone of the Mediterranean diet, recognized for its unique aroma and its beneficial properties. The positive and negative sensory characteristics of VOOs are due to the presence of volatile organic compounds (VOCs). However, these attributes and their perceived intensity can change over time, due to factors such as oxidation which can be accelerated under inadequate storage conditions. VOCs can be used to monitor changes in VOO characteristics selecting specific markers linked to defects (e.g. rancid) and molecules responsible for fruity or other green notes. For these reasons this study aims to profile the VOOs volatilome, tracking the evolution of selected volatile markers over a storage of several months. The samples were sensory classified according to the application of the official method, known as Panel test and analysed with a semi-targeted approach by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), as support to the sensory assessment through the application of PLS-DA chemometric models. Furthermore, VOCs were analysed by a targeted validated method using solid phase microextraction (SPME) in combination with gas chromatography (GC) coupled to mass spectrometry (MS). An integrated approach of sensory and metabolomic analysis can allow a more complete assessment of the modifications that occur in VOO during storage, monitoring potential changes in lipid oxidation markers and molecules responsible for positive and negative sensory attributes. This research work is developed within the project funded under the National Recovery and Resilience Plan (NRRP) - NextGenerationEU “ON Foods - Research and innovation network on food and nutrition Sustainability, Safety and Security - Working ON Foods”.