Extraction: are you up to speed?

Fotolia_68349123_SFine-tuned over the years to keep pace with scientific advances and industrial processes, extraction methods have become an ingenious blend of tradition and science. Follow in the footsteps of the great explorers of this realm of knowledge and see how you measure up. Do you know which of the following five statements are true and which are false?

Statement No. 1: a plant extract is necessarily obtained by solid-liquid extraction.

TRUE. Solid-liquid extraction is an operation that separates active ingredients contained in a solid by dissolution in a solvent. With the exception or pressing, which is used to extract initially liquid ingredients, solid/liquid extractions are the only way of harnessing the active ingredients from plants. A fact for your travelogue: the early explorers of these techniques primarily obtained active ingredients by aqueous extraction or fermentation in alcohol. The best known solid/liquid extraction methods include:

– infusion: hot water is poured over a plant, just like when we make a herbal tea

– decoction: the plant is mixed in water and then brought to the boil

– maceration: the plant is soaked cold in a solvent (oil, brine or alcohol for example)

Statement No. 2: plant extractions are only possible with leaves.

FALSE. Active ingredients can be extracted from any part of a plant: leaves, pips, seeds, stems, bark, roots, trunk, flowers. The extraction method used depends on the part in question and the properties of the active ingredient (solubility, heat sensitivity, etc.). For roots, bark or trunk, however, the active ingredients of interest are more difficult to extract. Decoction is ideal for optimum extraction. At Purextract, our explorers are equipped to extract active ingredients from maritime pine bark, grape seeds, olive leaves and a whole lot more besides.

Statement No. 3: the choice of raw materials is of little significance compared to the other extraction parameters.

FALSE. The selection of raw materials is the most important factor for high-quality extraction, but the most difficult to control. That’s because good extracts are, first and foremost, extracts of consistent quality. However, very often, the plant from which extracts are to be taken is of variable quality – even for the same variety – depending on climatic conditions, geographic origin and farming practices. It’s for this reason that careful selection of our suppliers is so crucial!

Statement 4: apart from raw material selection, other factors have very little effect on the final quality of the extract.

FALSE. There are many different extraction methods and their industrial-scale use varies depending on numerous parameters. To selectively obtain specific active ingredients rather than others, it is also necessary to determine the best processes, solvents and industrial equipment for optimum extraction results. At Purextract, it is the judicious combination of all these parameters that guarantees an excellent level of selectivity and hence the high OPC, phytosterol and polyphenol content of our extracts.

Statement 5: a purification step is not mandatory.

TRUE. Once an extract has been obtained, it often still contains impurities. Liquid-liquid extraction using a solvent is a purification method based on the difference in solubility of a solute in two non-miscible phases. Since this is not compulsory, most ingredient suppliers are quite happy to perform only a solid-liquid extraction. To guarantee the good quality and high level of purity of its olive leave, grape seed and pine bark extracts, Purextract has opted to optimize its extraction process by taking it a step further.

We have reached the end of this journey of initiation through the world of plant extraction and we are unable to take you any further along this path of discovery, since we cannot reveal all the secrets of this art so jealously guarded by our technical experts. It is these that make our extracts so unique on the market in terms of their purity.