Extraction and purification of crocin from saffron stigmas employing a simple and efficient crystallization method

In this study, total crocin was extracted from saffron stigmas using crystallization method. Ethanol 80% was selected as the best extraction solvent. Crystallization process was carried out in one and two steps at different temperatures. Ethanol 80% was used as crystallization medium. Crocin crystals obtained from the first crystallization had low purity and thus were subjected to the second crystallization. The higher purity crystals were yielded in the second crystallization at -5 degrees C. The purity of crocin crystals was studied using UV-visible spectrophotometery and HPLC in comparison with Fluka product and methanolic extract of saffron stigmas. The results indicated that its purity was extremely higher, about 13 times, more than Fluka product. In spite of our expectation, the Fluka product was not a pure alpha-crocin sample; five other types of crocins in addition to an unknown impurity were seen in its chromatogram. The purity of crystallized total crocin in this work was more than 97%.