Chromatographic fingerprint of Pistacia vera fruits: an aromatic tour around the world

Aroma is a key organoleptic characteristic of pistachio that determines its quality and consumer acceptance. As for all the natural products, the aroma is highly dependent on many variables such as the cultivar, geographical origins, harvesting conditions, storage, etc. Most of the pistachio production comes from countries with a warm, arid climate, indeed, the world’s leading producers of pistachio are Iran, the United States (USA), Italy, Greece, Tunisia, Turkey, Syria, and Spain. Determining their characteristic aroma fingerprints is essential not only from a consumer acceptance viewpoint but also for standardizing pistachio-based product production in industries. In the present study, the volatile organic compounds (VOCs) of pistachio from different geographic origins, were evaluated. To perform this evaluation, a high-capacity concentration (HCC) tool, named HiSorb™, was used. HiSorb™ bridges the gap between solid phase micro-extraction (SPME) and stir bar sorptive extraction (SBSE); increasing sensitivity and repeatability, thanks to an automated and easy handling interface. Different HiSorb™ probes were evaluated to obtain the best results, as well as temperature and time of extraction. VOCs extracted with HiSorb™ were successively analyzed with two-dimensional comprehensive gas chromatography-mass spectrometry (GC×GC-MS), equipped with a reversed fill/flush flow modulator. The use of multidimensional gas chromatography allows an enhancement of separation power and maximises the level of information extracted, obtaining in this way a chromatographic fingerprint of pistachio’s VOCs.