Preliminary studies on edible saffron bio-residues during different post-harvest storages

Huge quantities of floral bio-residues (tepals, stamens, and styles) are produced annually after the removal of stigmas from Crocus sativus flowers. This material is rich in polyphenols and completely edible. In this work, some preliminary analyses were performed on saffron bio-residues kept in different post-harvest storage conditions (dried at 34 °C or frozen at -20 °C, respect to fresh flowers stored at 4°C as control) in order to select which treatment was able to preserve more quantities of bioactive compounds (polyphenols and carotenoids) in these floral tissues. Analysis of volatiles highlighted a significant presence of monoterpenes and non-terpenoid substances in control flowers, while dried flowers were characterised by a high percentage of phenylpropanoids. Analyses carried out on dried or frozen anthers and tepals provided good amount of compounds with antioxidant activity (polyphenols, anthocyanins and flavonoids in tepals and carotenoids in anthers).