The soapnut, also commonly known as a soapberry or washnut, is the fruit from the tree Sapindus mukorrosi . Sapindus mukorrossi, known as the Ritha tree in Nepal , is a deciduous tree that is grown in the lower foothills and midhills of the Himalayans , up to altitudes of 4000 feet . It is tolerant to reasonably poor soil, can be planted around farmers’ homes , and one Ritha tree can produce 30-35 kg of fruit per year . Due to the characteristics outlined above, it is an ideal crop for subsistence hillside farmers in Nepal, and the product has many uses for the Nepalese and Canadians.
The value of the tree mostly comes from its fruit, which can be used for many pharmacological and cleansing purposes including, but not limited to, the ones outlined below . The multi-purpose nature of the soapnut is undoubtedly beneficial to Nepalese subsistence families, since their crop can provide them with many personal uses beyond just income from selling their product.
The soapnut contains the compound of saponins, which has natural cleansing properties, and therefore the soapnut can be used as a cleanser for hair, skin, and clothing . These saponins are also useful as insecticide, for purposes such as removing head lice off of the scalp .
Upadhyay and Singh  have suggested that the soapnut can also be used as a natural remedy for many health problems, such as for treating migrane headaches, or for dermatological purposes such as using the seeds to remove skin impurities like pimples or eczema.
Methods of extracting the maximum amount of oil from existing oil reserves has become a scientific focus in a world that has become dependent on fossil fuels. Researchers have found that the Ritha fruit can be used in an enhanced oil recovery technique . More specifically, Chhetri, Watts, Rahman, and Islam (2009) found that extracts from the soapnut can be used as an organic surfactant to increase the mobility of oil from the fields. In addition, researchers have demonstrated the potential for the soapnut to be used as a natural surfactant for washing arsenic from soils that are rich in iron .
Other Benefits to Producers
The Non-timber Forest Products (NFTPs) sub-sector makes up about 5% of Nepal’s GDP, and in some rural foothills, NFTPs can make up 50% of a subsistence farmers’ family income . Poudel (2011) has concluded that the soapnut tree is one of the 10 most important NFTPs in Nepal, and efforts should be made to increase the promotion of this product.
Researchers have previously rated the Ritha tree on a five-point scale to compare it to other Nepalese NFTPs , and it was rated at the top end of the scale for regeneration properties, social acceptance, and quality improvement potential. According to Poudel (2011), the tree was also rated fairly well for ease of cultivation. These favourable ratings suggest that the Ritha tree is highly regarded as an export product by researchers.
Production and Environment
The production of soapnuts can fit easily into a farmer’s subsistence lifestyle. The Ritha tree can be grown around houses, and there should be wide-spacing between the trees . This wide-spacing would be a benefit to farmers, as they could intercrop with other plants. In addition, because the tree is a perennial , farmers can benefit from the crop without having to plant every year. Also, in terms of processing before exporting, the fruit only needs to be dried on the roof of farmer’s homes , thus storage and shipment does not become an issue since the product is dry. It would appear that the production also has minimal impact on the environment due to low input and processing, and roots that mount in poor soils on hills, which could reduce erosion. It appears that the soapnut has great potential for farmers and does not negatively impact the environment.
There are a few considerations when deciding to produce soapnuts. The results of a Community Forestry Development Project have shown that Ritha trees growing on individual farmer’s land, in 1981-1982, had a survival rate of 43%  and more recently researchers have concluded that a large proportion of the Ritha tree mortalities occur in the seedling stage . This suggests that farmers may experience loss of crops and no gains when first beginning to plant the trees. However, micropropogation methods followed by transfer to the natural environment have proven successful in the past . Another potential drawback is the low sales price of soapnuts from the producer, at about eight Nepalese rupees per year, per tree . However, due to the relatively low level of maintenance and labour input required, farmers can potentially plant a larger number of Ritha trees in order to gain more income off of the product.
1. Upadhyay, A., & Singh, D. K. (2012). Pharmacological effects of Sapindus mukorossi. Revista do Instituto de Medicina Tropical de São Paulo, 54(5), 273-280. doi: 10.1590/S0036-46652012000500007
2. Orwa C. A., Mutua, K. R., & Jamnadasss R. S. A. (2009) Agroforestree Database: a tree reference and selection guide (version 4.0). Retrieved from http://www.worldagroforestry.org/treedb/AFTPDFS/Sapindus_mukorossi.pdf
3. Sharma, A., Sati, S. C., Sati, O., Sati, D. M., & Kothiyal, S. K. (2011). Chemical constituents and bio activities of genus Sapindus. International Journal of Research in Ayurveda & Pharmacy, 2(2), 403-409. Retrieved from http://www.ijrap.net/vol2/issue2/15.pdf
4. Sarin, J. L., & Beri, M. L. (1939). Extraction of saponin from soap nut. Industrial and Engineering Chemistry, 31(6), 712-713. Retrieved from http://pubs.acs.org.subzero.lib.uoguelph.ca/doi/pdf/10.1021/ie50354a012
5. Forestry Nepal (2014). Sapindus mukorossi. Retrieved from http://www.forestrynepal.org/resources/trees/sapindus-mukorossi
6. Poudel, K. L. (2011). Trade potentiality and ecological analysis of NTFPs in Himalayan Kingdom of Nepal. Himalayan Research Papers Archives, 61. Retrieved from http://hdl.handle.net/1928/3300
7. Chhetri, A. B., Watts, K. C., Rahman, M. S., & Islam, M. R. (2009). Soapnut extract as a natural surfactant for enhanced oil recovery. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 31(20), 1893-1903. doi: 10.1080/15567030802462622
8. Mukhopadhyay, S., Hashim, M. A., Sahu, J. N., Yusoff, I, & Gupta, B. S. (2013). Comparison of a plant based natural surfactant with SDS for washing of As(V) from Fe rich soil. Journal of Environmental Sciences, 25(11), 2247-2256. doi: 10.1016/S1001-0742(12)60295-2
9. Philomina, N. S., & Rao, J. V. S. (2000). Micropropagations of Sapindus mukorossi Gaertn. Indian Journal of Experimental Biology, 38, 621-624. Retrieved from http://nopr.niscair.res.in/bitstream/123456789/23996/1/IJEB%2038(6)%20621-624.pdf
10. Earth’s Berries Soap Nuts (2014). Our soap nut supplier. Retrieved from http://www.earthsberries.com/
11. Superior Soapnuts (2008). Use soapnuts for natural cleaning: Superior Soapnuts. Retrieved from http://www.superiorsoapnuts.com/index.html
12. The Wholesome Market (2014). About us. Retrieved from http://wholesomemarket.ca/
13. Government of Nepal (2012). Trade policy review. Retrieved from http://www.mocs.gov.np/uploads/Press%20Release/TPR%20Nepal_Government%20Report.pdf