An efficient elution system for enrichment and separation of Saffron's Major compounds using macroporous resin

Abstract

Saffron, also known as Crocus sativus L., is a high-value, low-volume agronomical crop celebrated for its unique flavor, color, cooking taste, and numerous health benefits. These properties could be attributed to its two compounds, crocins and safranal, which safranal derived from picrocrocin. Therefore, separating and enriching these chemicals are vital for unlocking the full therapeutic potential of saffron including its pharmaceutical, cosmetic, and industrial applications. One effective method for this target is using macroporous adsorption resins, which offer a cost-effective approach with a high capacity for isolating the desired molecules. In this study, various macroporous polystyrene/divinylbenzene (SDVB) based resins, including HP-20, LXA-10, LXA-8302, and LX-68, were studied to separate and enrich crocins and picrocrocin from the saffron extract. HP-20 was selected as the best adsorption system in terms of kinetic and isotherm data interpretation, in which the pseudo-second-order kinetic model and the Langmuir isotherm model were well-fitted for the target crocins and picrocrocin, respectively. The maximum adsorption capacity and percentage for crocins were 262.1 mg. g⁻¹ and 91.3 %, respectively, while for picrocrocin, they were 267.7 mg. g⁻¹ and 83.1 %. An efficient elution system using ethanol solvent was conducted in the desorption step. The optimal desorption of picrocrocin was achieved using four times the bed volume of 15 % ethanol, followed by the complete desorption of crocins with 80 % ethanol. The application of HP-20 resulted in high yields of 99.3 % for crocins and 92.9 % for picrocrocin, with enrichment factors of 4.7 and 5.8, respectively. The proposed methodology offers a cost-effective solution for the large-scale purification of saffron's major components, ultimately enhancing its value.