How is saffron extract obtained?

The saffron is a spice derived from the flower of Crocus sativus, a perennial plant belonging to the Iridaceae family. Originating from certain regions of Asia and the Middle East, saffron is renowned for its numerous culinary and cosmetic virtues. It is a rare spice, the cost of which is almost as high as that of gold (≈ £30 to £35 per gram). It contains beneficial compounds for the skin and hair, such as crocin, crocetin, safranal and picrocrocin, four active ingredients that give it its properties.

Saffron is particularly recognised for its antioxidant power , which provides significant protection against oxidative damage caused by free radicals. It also has a anti-inflammatory activity that is beneficial for acne-prone skin. Finally, a recent study showed that the daily application of a cream enriched with 3% saffron extract was able to reduce transepidermal water loss (TEWL) and increase overall skin hydration .

Saffron extract, whether intended for cosmetic or culinary use, is generally obtained by solvent extraction, also known as solid/liquid extraction. The principle involves macerating the flower in a liquid or semi-gaseous solvent, such as supercritical CO2. Regarding liquid solvents, the most commonly used are a mixture of water and methanol (50% - 50% or 20% - 80%) and a mixture of water and ethanol (20% - 80%). The extraction steps are as follows:

1. Harvesting of Stigmas : Saffron comes from the dried stigmas of saffron flowers. The stigmas are the vivid red parts of the flower, which are hand-harvested during the short saffron flowering period, typically in the autumn.

2. Drying of the Stigmas : Following the harvest, the saffron stigmas are meticulously separated from the rest of the flower. They are then dried in open air or in specialised dryers, at a controlled temperature between 35 and 45°C, to preserve the properties of the saffron.

3. Extraction of Active Compounds : Once the saffron stigmas are dried, the extraction of active compounds begins. For this, the dried stigmas are ground and placed in a flask with a liquid or semi-gaseous solvent. They are then left to macerate for a few days so that the active ingredients can dissolve in the solvent.

4. Purification and Concentration : The obtained extract undergoes various purification processes to remove impurities and yield a product more concentrated in active compounds. Filtration and decantation stages are notably involved. The solvent is then evaporated via a rotary evaporator under reduced pressure. The temperature depends on the solvent used, for example, it is 40°C in the case of ethanol.