by: Kwan H Lo
Herbal supplements have many health benefits. Many of them are potent antioxidants. Some have antiviral, antifungal, antibacterial, and antitumor properties. Some improve general bodily functions such as digestion, mental clarity, circulation, hormonal balance, etc. Many people also consume herbal supplements to prevent and treat common ailments and improve the overall well beings.
Herbal supplements contain active constituents extracted from dry or fresh herbs. These active constituents can be divided into two main groups based on their chemical properties, hydrophilic (water loving) and lipophilic (oil loving). Traditionally, hydrophilic compounds are extracted in water and ethanol whereas lipophilic compounds are extracted in chemical solvents such as acetone and hexane.
The use of chemical solvents in extracting lipophilic compounds has raised some health, environmental and safety concerns in recently years. First of all, there is a small amount of toxic residues left after the extraction process, which can pose a health threat to the consumers. Secondly, the disposal of organic solvents is detrimental to the environment. And lastly, these chemical solvents are toxic and highly volatile, handling of these chemicals require extreme caution.
Unfortunately, the major active constituents in many herbs such as ginger, St. John’s Wort, valerian, rosemary are lipophilic. In the past, they were extracted by organic solvents such as acetone and hexane. But the advance in new technologies has provided safer alternative to the food industry. Supercritical fluid extraction is one of these new technologies. It allows health food manufacturers to produce cleaner, more potent and stable herbal products.
Supercritical fluid extraction (SFE) using carbon dioxide (CO2) is an improved extraction method. Carbon dioxide is non-toxic, non-explosive and can be readily removed from the finished products and recycled. It does not pose any hazardous problems to the environment. The extraction takes place without high temperature heating and boiling so the extracted products are more stable. In addition, the extraction yields a highly concentrated herbal extract.
In comparison, chemical extraction using organic solvents leaves adsorbed chemical residues in the finished products. The solvents may react with the active compounds and degrade them. To remove the solvents from the extracted products, high temperature heating is required, which may degrade the active constituents. As a result, the quality of the extracted products is generally inferior to that from supercritical fluid extraction.
The commercial application of supercritical fluid technology is still limited to few high valued products due to high investment costs and new operation. New chapter is one premium brand producing herbal and fatty acid supplements using this new technology. With the increasing public demand of purer, cleaner nutritional supplements, one may assume that more companies would be applying this new extraction technology in the near future.
Source : http://www.articlecity.com/articles/health/article_5503.shtml