A high-performance liquid chromatography with photodiode array detection method (HPLC-DAD) was validated for the analysis of floral bioresidues obtained in saffron spice production by using three different solvent mixtures [water/hydrochloric acid (HCl) (100:1, v/v), water/acetonitrile/trifluoroacetic acid (47:50:3, v/v/v), and water/acetonitrile/HCl (50:50:1, v/v/v)]. Fifteen phenolic compounds were tentatively identified, kaempferol 3-O-sophoroside and delphinidin 3,5-di-O-glucoside being the main ones. The extracts showed very different phenolic profiles obtained by HPLC-DAD coupled with electrospray ionization mass spectrometry (ESI-MSn), and several experiments were carried out to explain this. The use of acetonitrile as solvent causes the chromatographic splitting of the peak of the delphinidin 3,5-di-O-glucoside into two peaks. Results obtained in this paper show that the extract prepared with water/HCl (100:1, v/v) would be the best suited for determining phenolic compounds in the quality control of the floral bioresidues from Crocus sativus L.
Keywords: Crocus sativus L.; delphinidin 3,5-di-O-glucoside; flower waste; kaempferol 3-O-sophoroside; quality control; validation.