The natural colorants of the Crocus sativus L. flower

Natural colorants (e.g., carotenoids and anthocyanins extracted from plants) have sparked considerable interest in recent years due to consumer concern for the safety of artificial dyes and reinforced by their potential health benefits. A rich natural source of carotenoids is saffron, the expensive spice obtained from the dried stigmas of Crocus sativus L. Crocins, i.e. water-soluble crocetin esters, are the principal yellow-red pigments of the spice. The content of these apocarotenoids can be affected by horticultural practices, such as the cultivation in open field or a greenhouse and the use of microbial biostimulants, such as arbuscular mycorrhizal fungi (AMF). More than 100,000 flowers are harvested to produce 1 kg of spice and the violet tepals are the main floral bio-residue. As saffron tepals contain anthocyanin pigments, they can be considered as a valuable by-product. The extraction performance of anthocyanins from saffron tepals depends on processing methods (e.g., drying) and the selection of suitable solvents.