Green chemistry for the benefit of high performance of phytochemicals: supercritical CO2 extraction

Some traditional methods of extracting phytochemicals combine a variety of organic solvents (hexane, methanol etc.), with or without heating, and different techniques for destroying the plant matrix. Among the many disadvantages of this process are the consumption of time and energy; the need for large amounts of water or petroleum-based solvents that are harmful to the environment and to the users themselves; and the generation of large amounts of waste. In addition to these issues, the resulting extract is not always safe to use and may contain residual solvents and contaminants in the plant matrix.

Committed to innovation in its ingredient manufacturing technologies, Chemyunion seeks solutions that include the concept of green chemistry – chemical processes to reduce the impact on the environment – using the supercritical extraction of carbon dioxide (Supercritical CO2 or Supercritical Fluid) as part of its program. 

Green extraction is inspired by processes that reduce energy consumption and allow the use of alternative solvents and renewable natural products, thus ensuring a safe extract with a high degree of purity. 

The supercritical carbon dioxide (Supercritical CO2 or Supercritical Fluid) stands above other existing possibilities for green extraction, by favoring the isolation of plant compounds in their purest and most concentrated form, eliminating the use of solvents, and preventing the accumulation of residues in the final product. 

For this reason, supercritical CO2 is considered the ideal supercritical fluid. By making use of clean technology, thanks to its constant low critical (required temperature and pressure 31.1°C and 73.8 bar, respectively), the only solvent used in the process is totally dissipated at the end of the extraction and re-captured for new applications, thus eliminating the release of waste to the environment. Supercritical CO2 is a non-toxic, non-explosive, low-cost process, and is readily available, easily removed from the final product and offers significant extraction capacity due to its greater penetration power. 

CO2 is generally regarded as a safe (GRAS) and non-polar solvent, suitable for the extraction of weakly polar and low molecular weight compounds, such as carotenoids, triglycerides, fatty acids, flavors, among others. For the extraction of polar compounds, the use of polar co-solvents is recommended, with ethanol being the most used co-solvent in the extraction of polar compounds such as phytosterols.

The supercritical extraction of phytosterols in some plant species can increase the concentration by up to 40 times when compared to traditional methods, making it an alternative to a higher concentration of active compounds, completely free of chemical contaminants and effectively purified.

What about using water as the greenest solvent? Despite being non-toxic, non-corrosive, non-flammable, environmentally friendly, naturally abundant and available at low cost, water has some disadvantages that limit its use as a universal solvent for sustainable extraction processes. These include low solubility of non-polar compounds and the high energy consumption required to concentrate the product. In its supercritical state, water is at temperatures above 374°C and pressures above 221 bar. In the temperature range of 100-374°C, water is called subcritical, almost critical or pressurized water. Although this type of extraction is also considered green (extraction by subcritical water), it requires a much higher energy usage than supercritical extraction by CO2, due to the need for the higher temperatures and pressures (between 30-120 bar). In addition, high extraction temperatures can cause the degradation of thermolabile compounds and are therefore normally avoided.   

Ingredients with sustainable extraction 

In addition to plant-based, organic certification and cruelty-free ingredients, Chemyunion also invests in green chemistry technologies within its portfolio by developing part of its raw materials through supercritical carbon dioxide extraction technology. 

Revinage® is one of the innovations for skin care and treatment that has highly pure, safe and effective active ingredients resulting from supercritical CO2. While this scientifically proven function of retinol-like products, without adverse effects for day and night, uses the supercritical CO2 extract of Bidens pilosa as its starting point, along with phytol and phytic acid acting in the same receptors as retinoids, offering both high performance and the concept of sustainability.

Do you want to know more about the benefits of green extraction with Supercritical CO2 in your creations? Schedule an online presentation by clicking here.