Nomenclatural History
Plukenetia volubilis was first described by the naturalist Carl Linnaeus in 1753, who assigned it the Linnean binomial name Plukenetia volubilis Linnaeus. The full taxonomic name is often abbreviated as Plukenetia volubilis L. or simply referred to as Plukenetia volubilis (Flores, 2010).
Common names for Plukenetia volubilis include inca peanut and sacha inchi. Sacha inchi comes from the indigenous Quechua language and roughly translates to 'false peanut'. This name reflects the interchangeable nature of peanuts and sacha inchi seeds in traditional cuisine.
Other names of both indigenous and Spanish origin are occasionally used, including sacha yachi, suwaa, correa, amauebe, maní estrella, and maní del monte (Kohdahl, 2020).Evolutionary History
Plukenetia volubilis is closely related to a number of other species in the Plukenetia genus, which is part of the Euphorbiaceae family (Cárdenas, 2021). The genus is comprised of two clades based on the venation of the leaves. Taxa in the pinnately veined clade have only one primary vein on each leaf. Taxa in the palmately veined clade, which Plukenetia volubilis belongs to, have between three and five primary veins (Kohdahl & Sørensen, 2021).
Species in the genus Plukenetia are widely distributed in tropical regions of the world, including Central America, Mexico, South America, Africa, Madagascar, and Southeast Asia. Analysis suggests that the genus originated in the forests of Brazil around 28.7 million years ago, and later dispersed to other regions. The ancestor of Plukenetia volubilis is thought to be the only lineage that dispersed to Central and South America and later returned to the Amazon during the Pliocene. During this time, rapid diversification in many taxa occurred due to the formation of the Andes. The common ancestor of Plukenetia volubilis and Plukenetia cf. carolis-vegae began to speciate along this new elevation gradient. Preference for different elevations allowed this common ancestor to diverge into the two extant taxa. Plukenetia volubilis favors low-to-medium elevations of 100-800 meters, while Plukenetia cf. carolis-vegae prefers high elevations of 1500-2500 meters (Cardinal-McTeague et al., 2019).Ecology and Life History
Plukenetia volubilis is found throughout the western and northern regions of the Amazon Basin. It is distributed through portions of Brazil, Bolivia, Perú, Ecuador, Colombia, Venezuela, Suriname, and the Lesser Antilles. The plant grows in moist, lowland forests, preferring disturbed areas and the edges of forests. Though it tends to grow at elevations under 900 m, it is capable of producing fruit up to altitudes of 1490 m elevation. Plukenetia volubilis can tolerate temperatures ranging between 10-37ºC. Plants typically flower 3-5 months after germination and fruit 8-9 months after germinating (Kodahl, 2020).
Though most commonly found in moist to wet lowland forests, Plukenetia volubilis can also occupy other ecological niches. Within the species, two groups with slight morphological differences exist, with the first being found at mid-elevations, and the second growing in open savannah (Kohdahl & Sørensen, 2021).Vegetative Morphology
Plukenetia volubilis belongs to the palmately veined clade of Plukenetia genus. It has palmately veined leaves, which are triangular to ovate in shape with truncate or cordate bases. The leaves have basilaminar glands that are usually separated by a small knob(Kohdahl & Sørensen, 2021).
The plant is deciduous, losing its leaves during portions of the year. Leaves are simple, have serrated margins, and are arranged alternately (Flores & Lock, 2012).
The plant is a perennial, semi-woody plant that frequently grows in a climbing habit. It grows to approximately 2 meters high. The basilaminate glands are rounded or elliptical and are noticeable on the axial surfaces of leaves. Leaves are 10-12 centimeters long and 8-10 centimeters wide, petioles are 2-6 centimeters long (Flores, 2010).
Reproductive Morphology
Plukenetia volubilis has both staminate (male) flowers and pistillate (female) flowers, arranged together in a racemose thyrse. It is monecious, meaning male and female flowers are present on the same plant. There is one or a few pistillate flowers at the base of the inflorescence, with several staminate flowers above the pistillate flower(s). The flowers are very small and do not have any petals, though they do have 4-5 greenish-yellow sepals (Kodahl, 2020).
The fruit of Plukenetia volubilis is lobed and typically has 4 carpels, though in cultivation is often has 5 carpels. Immature fruits are green and fleshy, and they darken in color as they dry. Each carpel contains a lenticular seed surrounded by a hard, dark brown testa (Kodahl, 2020). Seeds are between 1.5 to 2 centimeters in diameter, and weigh between 48 to 100 grams (Flores, 2010). Mature seeds are released from the capsules around two weeks after maturation. The capsules dehisce as they dry, releasing the seeds to the ground. This occurs nearly year round, with one plant often containing seeds at various stages of maturity (Bueno-Borges et al., 2018).Historical Accounts
There is archaelogical evidence that sacha inchi was cultivated by the Incas around 3000-5000 years ago. Inca grave sites include depictions of sacha inchi plants and seed pods (Kodahl, 2020).
In his account of Incan history, published in 1609, Garcilaso de la Vega mentions that the native people called the plant "inchic" and the Spanish called it "maní". He describes that the taste of inchic is similar to almonds, and that it must be eaten roasted or else there are negative effects. He also mentions that it can be mixed with honey to make a dessert, and that oil from the plant is used to treat a variety of illnesses (Flores, 2010).Domestication History
Though Plukenetia volubilis is not entirely domesticated, there is evidence of ancient semi-domestication in the Plukenetia genus. Cultivated species with larger seeds are present on multiple continents, suggesting that at least two independent domestication events occurred, one in South America and one in Africa (Cardinal-McTeague et al., 2019). Recent efforts to fully domesticate Plukenetia volubilis and increase the prevalence of desirable traits have focused on increasing seed size to generate larger harvest yields. There has been both targeted breeding and selection during replanting, where farmers only utilize the largest seeds when establishing Plukenetia volubilis plantations (Kohdahl, 2020).
Plukenetia volubilis displays high amounts of genetic diversity between wild populations, which is promising for domestication efforts. The plant can also be propagated by cuttings to produce genetically identical plants which take less time to flower than plants grown from seed (Kohdahl, 2020).Cultivation Practices
Sacha inchi has been cultivated in its native range by the indigenous people of Peru for generations. It is grown primarily in the lowlands and is incorporated into the traditional diets of a number of indigenous groups as a staple (Supriyanto et al., 2022).
Sacha inchi grows well in a number of other regions worldwide. It is cultivated outside of its native range in Central and South America. It is also grown in Asian countries, including China, Thailand, and Vietnam (Cárdenas et al., 2021).
It is beginning to be cultivated in Indonesia as well, where trials are being conducted to determine the best methods of cultivating the crop (Supriyanto et al., 2022).Nutritional Value
The most remarkable property of Plukenetia volubilis is the extremely high level of essential polyunsaturated fatty acids, including both omega-3 and omega-6, contained in the seeds. The seeds are 45–55% lipids, with nearly 85% of the total lipid content attributed to omega-3 and omega-6. The raw seeds of Plukenetia volubilis contain around 22-30% protein, making them a valuable source of nutrition. The plant also contains a variety of amino acids, including tyrosine, isoleucine, lysine, and tryptophan (Kohdahl & Sørensen, 2021). Not only does this plant contain valuable proteins and amino acids, it also contains antioxidants. Around 21 phenolic compounds are found in the oil, which increase in frequency as the roasting intensity of the seeds increases (Kodahl & Sørensen, 2021). Research has also shown that the plant contains essential fatty acids, phenolic compounds, and vitamin E, which have been shown to have health benefits (Cárdenas et al., 2021). The antioxidative properties derived from the plant may help reduce the risk of cancer, coronary heart disease, and stroke. Plukenetia volubilis seeds and seed oil are commonly consumed for their nutritional value (Kodahl & Sørensen, 2021).
Culinary Applications
Though the seeds and seed oil are most often consumed, the leaves have also been eaten in salads or dried and made into tea. Roasted and salted seeds are eaten as a snack. Seeds can also be coated in chocolate as a dessert, ground into butter, or milled into flour (Kohdahl & Sørensen, 2021).
Sacha inchi has been used in traditional Peruvian cooking in a variety of ways, and can be used as a substitute for peanuts. There are numerous examples of traditional Peruvian foods that can be made using sacha inchi seeds. Incachapi is a soup made from boiling sacha inchi, corn, chicken, garlic, and coriander. Porridges can be made by boiling plantains and sacha inchi together, including lechona api (made with green plantains) and pururuca (made with ripe plantains). Sacha inchi can also be made into a butter by roasting it and then grinding it with salt and water (Flores, 2010).Medicinal Value
A historical account by Inca Garcilaso de la Vega mentions that indigenous people used oil from sacha inchi for the treatment of many illnesses (Flores, 2010). Numerous indigenous groups in Peru have traditionally used sacha inchi for medicinal purposes. The Mayorunas, Chayuhitas, Shipibas, and Boras grind seeds and oil into a revitalizing skin cream. The oil is used to treat muscle pain and rheumatism by the Secovas, Candoshis, Amueshas, and Cashibos. In a study conducted in San Martín, 67% of the Peruvian respondents said they utilized sacha inchi for health reasons. The seeds and oil are purported to have positive effects on cholesterol, cardiovascular function, and gastrointestinal health (Kohdahl & Sørensen, 2021).
Scientific studies investigating the health benefits of sacha inchi have been promising. The seeds and seed oil are most often investigated, though some studies have also looked at extracts from the leaves of the plant. There is growing evidence that the plant may help reduce the risk of certain diseases, including dermatitis, chronic inflammatory disease, and cardiovascular disease. It has also been shown to potentially discourage tumor growth. Compounds found in the plant, notably essential fatty acids, phenolic compounds and vitamin E, are known to act as antioxidants, reduce cholesterol, support immune function, and have positive effects on skin health (Cárdenas et al., 2021).References
Bueno-Borges, L. B., Sartim, M. A., Gil, C. C., Sampaio, S. V., Rodrigues, P. H. V., & Regitano-d'Arce, M. A. B. (2018, October). Sacha inchi seeds from sub-tropical cultivation: Effects of roasting on antinutrients, antioxidant capacity and oxidative stability. Journal of food science and technology. Retrieved May 29, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6133840/
Cárdenas, D. M., Gómez Rave, L. J., & Soto, J. A. (2021, September). Biological activity of Sacha Inchi (plukenetia volubilis linneo) and potential uses in human health: A Review. Food technology and biotechnology. Retrieved May 29, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8542186/Cardinal-McTeague, W. M., Wurdack, K. J., Sigel, E. M., & Gillespie, L. J. (2019, January 22). Seed size evolution and biogeography of Plukenetia (Euphorbiaceae), a pantropical genus with traditionally cultivated oilseed species - BMC ecology and evolution. BioMed Central. Retrieved May 28, 2022, from https://bmcecolevol.biomedcentral.com/articles/10.1186/s12862-018-1308-9
Flores, D. (2010, August 31). Uso Histórico: Sacha Inchi Plukenetia Volubilis L. Centro de Información | Repositorio Institucional. Retrieved May 29, 2022, from https://repositorio.promperu.gob.pe/handle/123456789/1371Flores, D., & Lock, O. (2012, December). Reassessing the ancient use of Sacha inchi (Plukenetia Volubilis L) for nutrition, health, and cosmetics. ResearchGate. Retrieved May 29, 2022, from https://www.researchgate.net/publication/286670270_Reassessing_the_ancient_use_of_
sacha_inchi_Plukenetia_volubilis_L_for_nutrition_health_and_cosmetics
Kodahl, N. (2020, March 17). Sacha Inchi (Plukenetia Volubilis L.)-from lost crop of the Incas to part of the solution to global challenges? - planta. SpringerLink. Retrieved May 28, 2022, from https://link.springer.com/article/10.1007/s00425-020-03377-3Kodahl, N., & Sørensen, M. (2021, May 25). Sacha Inchi (Plukenetia Volubilis L.) is an underutilized crop with a great potential. MDPI. Retrieved May 28, 2022, from https://www.mdpi.com/2073-4395/11/6/1066/htm
Supriyanto, S., Imran, Z., Ardiansyah, R., Auliyai, B., Pratama, A., & Kadha, F. (2022, March 4). The effect of cultivation conditions on Sacha Inchi (Plukenetia Volubilis L.) seed production and Oil Quality (Omega 3, 6, 9). MDPI. Retrieved May 29, 2022, from https://www.mdpi.com/2073-4395/12/3/636/htm
