Different techniques for extraction and micro/nanoencapsulation of saffron bioactive ingredients

Background: Saffron is an enriched pool of bioactives including crocins, crocetin, safranal, picrocrocins, essential oils, minerals and trace amounts of B1 and B2 vitamins. Obtaining any valuable ingredients like bioactive compounds which are naturally present in plants is completely depending on the extraction and purification procedures. An efficient extraction method of bioactives should meet the green chemistry aspects including safety, environment-friendly, run-down or at least little impurities, efficiency, and economic requirements. On the other hand, efficient entrapment of saffron bioactive compounds into the protected carriers is indispensable owing to their liability to the operational (process), environmental, and body digestive conditions. Scope and approach: This review will present recent advances on the extraction and encapsulation of saffron bioactive components which could result in value-added products from the so-called red gold (saffron) as the most expensive spice in the world for different purposes such as food, pharmaceutical, and cosmetic formulations. Key findings and conclusions: Many different extraction methods, alone or in combination, have been exploited to produce the bioactives from saffron such as convectional routes (e.g. maceration and solvent extraction) and the modern routes (e.g. supercritical fluids, pulsed electric field, emulsion liquid extraction, microwave, sonication, etc.). Encapsulation techniques are strongly proposed to shelter the bioactive compounds found in saffron, over the other protective techniques. In this regard, microencapsulation (spray drying, freeze drying, extrusion, emulsion systems) and nanoencapsulation (nanoemulsions, solid lipid nanoparticles and nanodispersions, nanohydrogels, electrospinning, nano spray drying) procedures have been investigated for saffron bioactives.