Types of Saponins

Saponin is a natural detergent that foams like soap.

Saponins are named after the soapwort plant, saponaria, and are glycosides (compounds that yield a sugar and an aglycon upon hydrolysis) with a unique foaming characteristic similar to that of soap. Saponins are made up of a polycyclic aglycone that is a choline steroid or a triterpenoid. Many plants and some food groups contain saponins.

Peas and Beans

Alfalfa contains several saponins.

Alfalfa, a flowering plant in the pea family (fabaceae), contains several saponins, including medicagenic acid and lucernic acid. The medicagenic acid is said to be to blame for the antinutritional effect of alfalfa, which limits its use in supplementary protein feed for swine and poultry. Alfalfa foliage tends to be low in saponin in springtime, and higher in the height of summer. Another variety of pea that contains saponins is the chickpea. Saponins are also found in common beans and soybeans.

Plants

Saponins are found in daisies.

Varieties of plant that contain saponins include the yucca, Christmas rose, asparagus fern, daisy and horse chestnut tree. One of the main saponin sources for commercial use is the yucca schidigera, which grows in Baja California's desert land. The use of yucca in soap can be traced back to Native Americans. The yucca saponins give beverages like root beer their foaming top. They also find a purpose in the mining industry and the cosmetic industry, for example in shampoo and lipstick.

Weeds

Many weeds contain saponins that can be harmful to livestock.

Many rangeland weeds in the United States, including corn cockle, soapwort, cow cockle and broomweed, contain saponins. This is a matter of concern due to the potential toxicity issues for feeding livestock. In northern Mexico, the pasture weed alfombrilla is responsible for loss of cattle and is feared to be spreading to the southwest United States. The effect of weed saponin is that it reduces the feed intake and growth rate of animals with a simple digestive system.

References

• Cornell University Department of Animal Science: Saponins
• Oregon State University - The Linus Pauling Institute; Saponins: Surprising Benefits of Desert Plants