Kinetics of polyphenol content of dry flowers and floral bio-residues of saffron at different temperatures and relative humidity conditions.

The cultivation of Crocus sativus L. is valued for its dried stigmas, but the rest of the parts of its flowers are increasingly important. Saffron flowers (SF) are natural sources of antioxidant compounds. Kaempferols and anthocyanins are the main compounds of the high-phenolic content of SF. This work studies the evolution of flavonols and anthocyanins of dry SF and floral bio-residues of saffron (FBR) and their kinetics at different temperatures and relative humidity (RH) conditions. There was a degradation process of anthocyanins that fitted a second-order kinetic model and kaempferols showed better fit in a first-order kinetics model. The best storage conditions for anthocyanins studied in SF and FBR was 25 °C and 23% RH. The main kaempferol (Kaempferol 3-O-sophoroside) was no deteriorated in FBR. These results could contribute to the using SF and FBR as food and active ingredients in cosmetic industry, as well as development of new food products.