Saponins occur widely in many plant species, including the soap nut tree Sapindus mukorossi, found in North India and Nepal, and the soap bark tree Quillaja saponaria native to South America.
Both species have long been known for their detergent qualities to local populations and both appear in personal care products currently on the market.
Saponins are glucosides consisting of a polycyclic aglycone called a sapogenin and a sugar side chain, joined by an ether bond.
The sapogenin is hydrophobic (not water soluble) whereas the sugar side chain is hydrophilic (water soluble), the combination of which leads to a stable soapy foam when in contact with water - producing the detergent-like quality that is of interest to the personal care industry.
Saponins can replace conventional chemical detergents such as sodium laureth sulphate that are becoming increasingly unacceptable to the consumer due to fears concerning the safety of the chemical.
Certain studies suggest that sodium laureth sulphate and other chemical surfactants can leave the skin dry and irritated, especially in individuals suffering from eczema and other skin conditions.
In addition such chemicals are not biodegradable, a factor that is becoming increasingly important to the environmentally-minded consumer.
In contrast, naturally occurring saponins provide the foaming agent necessary in shampoo or shower gel, whilst being both gentler on the body and environmentally friendly.
A small number of products containing soap nut extracts are currently on the market, for example Sapon'hair, a shampoo recently released by a small French manufacturer Cosmigea.
The product contains 100 per cent plant and plant based ingredients and remarkably high proportions (70 per cent) of soap nut extracts.
Creator of the product Mehdi Ouahchi told Cosmetics Design that his unique selling point was the mix of ancient Ayurvedic traditions with traditional European natural ingredients.
His product combines the soap nut extracts from India with Rosemary oil to calm the scalp and tone the hair shaft, and cider vinegar to rid the hair of chlorine and calcium residues.
Other products to be released by Cosmigea in the autumn include a range of bath soaps containing a mix of soap nut extracts and vegetable oils such as jojoba, olive and macadamia.
The soaps will be manufactured at low temperatures, which will not damage the oils, and any fats that rest unconverted in the saponification process will remain in the product to hydrate the skin.
Cosmigea is one of a large number of small manufacturers specializing in natural products that appeal to an ever-growing consumer base, with market research company Organic Monitor estimating that the revenues of the global naturals market are doubling every few years.
Cosmigea products can be found at www.consomacteurs.com specialists in eco-products and natural cosmetics.