Identification and characterisation of volatile fingerprints of saffron stigmas and petals using PTR-TOF-MS : Influence of nutritional treatments and corm provenance

This study investigated the effects of different agronomical practices of saffron on the volatile organic compounds (VOCs) of saffron stigmas and petals using proton transfer reaction-time of flight-mass spectrometry. Saffron flower samples treated with different nutritional treatments as well as samples of corms of different provenances were harvested from a three-year-old saffron field. The results revealed that 2(5H)-furanone, safranal, acetic acid, and isobutanal contributed mostly (more than 55% of the identified VOCs) to the volatile profile of the ground saffron stigmas samples. 2(5H)-Furanone, isobutanal, 2,3-butanedione, and acetic acid was likely responsible for the overall aroma of the petals, as it accounted for 67%, 7%, 5%, and 5% of the identified VOCs, respectively. Based on the mass spectral data measured, 2(5H)-furanone and safranal were not the dominant volatile compounds in the intact stigmas samples. In intact form, isobutanal, acetic acid, methanol, and acetone were the most abundant compounds. This finding must be considered in saffron-related analyses. The compounds that were the most abundant in the aroma profile of saffron were the same in both the conventionally and organically grown corms, in spite of some differences in intensities. In general, the organically grown samples presented a higher concentration in safranal, 2(5H)-furanone, phenol, and 1-t-butylcyclopentadiene, whereas acetaldehyde and isobutanal concentrations were higher in the saffron stigmas grown with mineral fertilizers. The organic nutritional treatments applied in this study may be useful for organic saffron producers to select treatments to achieve saffron with high quality. Variation in VOCs in petals and stigmas among corms originating from different regions verifies that the selection of the most suitable corms can be considered as an important factor affecting the quality of saffron.