Crocus sativus L. flowers valorisation as sources of bioactive compounds.

The application of circular economy principles is of particular interest for the agricultural and agri-food sector, given the large amount of waste matrix of some plant species. In recent decades the attention towards the cultivation of saffron (Crocus sativus L.) has been rediscovered. The saffron produced from dried stigmas of Crocus sativus L. has been known since ancient times for its numerous therapeutic properties. The spice is obtained from the stigmas of the flowers, while petals and stamens are 90% waste material. The recovery of the flowers, considering the considerable amount of polyphenols with high antioxidant activity present in this matrix (kaempferol and quercetin glycosides) allows its use for innovative purposes in different product sectors such as foods, cosmetics and biomedical applications. In this context, the present work evaluated the polyphenol content in flowers of C. sativus grown in Tuscany, in order to characterize this product from a qualitative-quantitative point of view for various product sectors. The quali-quantitative analysis of the extracts was carried out by HPLC/DAD/MS analysis. Given the potential of this matrix, another aspect of the research consists in evaluating the possible tumor growth inhibition activity on kidney and bladder cancer cell lines by the extracts of petals.