Оңтүстік Америкалық мака тамырының сипаттамасы

Plant species native to South America grown for its edible fleshy hypocotyl

Lepidium meyenii, known as maca or Peruvian ginseng, is an edible herbaceous biennial plant of the family Brassicaceae that is native to South America in the high Andes mountains of Peru and Bolivia. It was rediscovered for commercial purposes at the Meseta de Bombón plateau close to Lake Junin in the late 1980s. It is grown for its fleshy hypocotyl that is fused with a taproot, which is typically dried, but may also be freshly cooked as a root vegetable. As a cash crop, it is primarily exported as a powder that may be raw, or processed further as a gelatinized starch or as an extract. If dried, it may be processed into a flour for baking or as a dietary supplement. Its Spanish and Quechua names include maca maca, maino, ayak chichira, and ayak willku.

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. 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. Most botanists 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. It has been debated whether it is botanically correct to consider meyenii and peruvianum to be distinct from one another.

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. The thin, frilly leaves sprout in a rosette at the soil surface, not growing more than 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 siliculate fruits, each containing two small 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. 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.

The natural environment of the maca is at 11–12ºS latitude and at an elevation of above sea level.

Maca (Peruvian ginseng) seedlings usually emerge about one month after sowing with the onset of the rainy season in October. In the vegetative phase, until May to June, the lower part of the hypocotyl, as well as the upper part of the tap root, grows in size. After 260 to 280 days, it is formed to the harvestable hypocotyl. If the root is left in the soil, it is dormant for two to three months in the time of the cold, dry season until August. Then it will form a generative shoot on which the seeds ripen five months later. One plant is capable of forming up to 1000 tiny seeds, 1600 of which together weigh about one gram. Thus, only relatively few plants are needed for propagation. The plants for cultivation are selected for preferred size and color, then placed 50–100 mm deep in pits with alternate layers of grass and soil to protect them from drying out. They are fertilized heavily, as maca is a soil exhaustive crop. 10–14% protein, 8.5% dietary fiber, and 2.2% fats.

Maca contains glucotropaeolin, m methoxyglucotropaeolin, benzyl glucosinolates, polyphenols, (1R,3S) 1 methyl 1,2,3,4 tetrahydro β carboline 3 carboxylic acid (MTCA), and p methoxybenzyl isothiocyanate. Alkamides are also present in maca. Maca contains several N benzylamides referred to as macamides that are structurally related to anandamide.

No pharmacokinetic data have been published for maca. 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.

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. 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. 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. 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 L. sativum and L. campestre, to which it is closely related genetically. 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. Archaeological evidence exists for varying degrees of cultivation of maca in the Lake Junin region from around 1700 BC to 1200 AD. 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 maize, rice, manioc (tapioca roots), quinoa, and papaya. It also was used as a form of payment of Spanish imperial taxes.

Maca is said to have medicinal properties, but scientific research remains inconclusive. A 2016 systematic review found evidence suggesting that it improves semen quality in healthy and infertile men. A 2011 systematic review found the evidence for the effectiveness of maca as a treatment for menopausal symptoms in women inconclusive.