Lepidium meyenii

Antonio Vázquez de Espinosa gave a description of the plant following his visit to Peru circa 1598 and Bernabé Cobo gave a description of this plant in the early 17th century.[2] Gerhard Walpers named the species Lepidium meyenii in 1843. In the 1990s, Gloria Chacon made a further distinction of a different species. She considered the widely cultivated natural maca of today to be a newer domesticated species, L. peruvianum.[3]

Most botanists now doubt this distinction, however, and continue to call the cultivated maca L. meyenii. The Latin name recognized by the USDA similarly continues to be Lepidium meyenii.[4] Debate is still ongoing about the correct nomenclature and whether the distinction between meyenii and peruvianum is botanically correct.[1]

Maca plants

The growth habit, size, and proportions of maca are roughly similar to those of radishes and turnips, to which it is related, but it also resembles a parsnip. The green, fragrant tops are short and lie along the ground.[5] The thin, frilly leaves sprout in a rosette at the soil surface, not growing more than 12–20 cm (4.7–7.9 in) in height. The leaves show a dimorphism according to reproductive stage. They are more prominent in the vegetative phase, and are continuously renewed from the center as the outer leaves die. The off-white, self-fertile flowers are borne on a central raceme, and are followed by 4–5 mm (0.16–0.20 in) siliculate fruits, each containing two small 2.0–2.5 mm (0.079–0.098 in) reddish-gray ovoid seeds. Seeds are the maca’s only means of reproduction. Maca reproduces mainly through self-pollination and is an autogamous species. The genome consists of 64 chromosomes. From experiments with different day lengths, maca is a short-day plant.[1] Some sources consider the maca to be an annual plant, as in favorable years it can complete a lifecycle within a year.[5]

Root

Maca root powder

Maca is the only member of the genus Lepidium with a fleshy hypocotyl, which is fused with the taproot to form a rough inverted pear-shaped body. Maca does vary greatly in the size and shape of the root, which may be triangular, flattened circular, spherical, or rectangular, the latter of which forms the largest roots. Traditionally, native growers have acknowledged four varieties of maca, based on their root color: cream-yellow, half purple, purple, and black; varying levels of anthocyanin is primarily responsible for the color differences.[2] Maca hypocotyls may be gold or cream, red, purple, blue, black, or green. Each is considered a "genetically unique variety", as seeds of the parent plants grow to have roots of the same color. Specific phenotypes (in maca, 'phenotype' pertains mainly to root color) have been propagated exclusively to increase commercial interest.[6] Cream-colored roots are the most widely grown and are favored in Peru for their enhanced sweetness and size. Black maca is both sweet and slightly bitter in taste.

(1R,3S)-1-Methyltetrahydro-carboline-3-carboxylic acid found in maca

The average composition is 60-75% carbohydrates, 10-14% protein, 8.5% dietary fiber, and 2.2% fats.[9] Maca contains polysaccharides.[10]

Maca contains glucotropaeolin, m-methoxyglucotropaeolin, benzyl glucosinolates, polyphenols, (1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid, and p-methoxybenzyl isothiocyanate.[6][11][12] Alkamides are present in maca.[13]

Due to its purported effects on fertility, maca grew in agricultural, commercial and research interest over the decades of the 1990s to 2014.[1][14] Market studies showed low acceptance of the particular maca taste by consumers when first exposed to it, creating a barrier for popularity of this food as a culinary vegetable. The economic interest existed more in the perceived, but unproven, health effects of the root's constituents supplied as an extract in a dietary supplement.[1][14]

By 2014, agricultural and market interest for maca grew in China, but with challenges from Peruvian institutions who accused Chinese companies of illegally exporting maca and of biopiracy, as several Chinese patents had been filed to improve the propagation and genetic diversity of maca.[15]

Maca is mainly grown for consumption of its root. The majority of harvested maca is dried. In this form, the hypocotyls can be stored for several years.[1][16] In Peru, maca is prepared and consumed in various ways, although traditionally it is always cooked. The freshly harvested hypocotyl may be roasted in a pit (called huatia), and is considered a delicacy. Fresh roots usually are available only in the vicinity of the growers. The root can also be mashed and boiled to produce a sweet, thick liquid, then dried and mixed with milk to form a porridge, mazamorra.[7] The cooked roots are also used with other vegetables in empanadas, jams, or soups. The root may be ground to produce a flour for bread, cakes, or pancakes. If fermented, a weak beer called chicha de maca may be produced. In 2010, a U.S.-based brewery called Andean Brewing Company, became the first company to produce and commercialize beer made from maca under the brand KUKA Beer.[17] From the black morphotype, a liquor is produced. Also, the leaves are edible or may serve as animal fodder. They can be prepared raw in salads or cooked much like Lepidium sativum and L. campestre, to which it is closely related genetically.

Maca root powder

The prominent product for export is maca flour, which is a baking flour ground from the hard, dried roots. It is called harina de maca. Maca flour (powder) is a relatively inexpensive bulk commodity, much like wheat flour or potato flour. The supplement industry uses both the dry roots and maca flour for different types of processing and concentrated extracts. Another common form is maca processed by gelatinization. This extrusion process separates and removes the tough fiber from the roots using gentle heat and pressure, as raw maca is difficult to digest due to its thick fibers and goitrogen content.

There is archaeological evidence for varying degrees of cultivation of maca in the Lake Junin region from around 1700 BC to 1200 AD.[18] Maca has been harvested and used by humans in the puna grasslands of the Andean Mountains for centuries. Contrary to frequent claims that maca's cultivation was common in what is today Peru, until the late 1980s, maca has been cultivated only in a limited area around Lake Junin, in central Peru. Historically, maca often was traded for lowland tropical food staples, such as corn, rice, manioc (tapioca roots), quinoa, and papaya. It also was used as a form of payment of Spanish imperial taxes.[5][19]