Analysis of saffron volatile fraction by TD-GC-MS and e-nose

Saffron spice is valuable for its colour, taste and aroma. All these properties depend on the different postharvesting treatments that Crocus sativus L. stigmas received to convert it into a spice. No previous scientific data relate the volatile content with its postharvesting process or origin. In this paper, two different analytical methods are used, CG-MS to determine volatile markers and an electronic nose based on metal oxides to determine the volatile profile of the samples from different geographic origins. It is demonstrated by means of CG-MS that 3,5,5-trimethyl-2-cyclohexenone, 2,6,6-trimethylcyclohexane-1,4-dione and acetic acid are capable to differentiate saffron from its origin. The content of acetic acid is very high in samples from Iran or Morocco, while low or undetectable content was observed in Greek and Spanish samples. In turn, using an e-nose (specifically optimised for this particular application), samples from different countries could be discriminated using Principal Component Analysis with a 90% of confidence.