Characterisation of secondary metabolites in saffron from central Italy (Cascia, Umbria).

Saffron's quality depends on the concentration of secondary metabolites, such as crocins, picrocrocin and safranal. The aim of this research was to evaluate the influence of drying conditions on the secondary metabolite contents of saffron produced in the area of Cascia, in central Italy. Different aliquots of the same saffron sample were subjected to various dehydration conditions and analysed by UV-Vis spectrophotometry to determine crocins, picrocrocin and safranal.. Safranal was also analysed by high resolution gas chromatography, while the crocins and picrocrocin were determined by high-performance liquid chromatography with diode array and mass spectrometric detectors. The results of chromatographic analyses showed that the samples dried in the milder conditions had the lowest content of secondary metabolites. Moreover the sample dried at 60°C for 55min presented the highest contents of trans-crocin-4 and picrocrocin, while safranal was most represented in saffron dried at 55°C for 95min.