- Nutrients
- Health properties
- Forms of consumption
- Precautions related to its use and production
- References
The pigweed (Amaranthus retroflexus) is a very abundant in nature and considered in many countries as a weed edible wild plant. It has been introduced on most continents and in a large number of habitats. Pigtail has been a part of traditional cuisine since ancient times.
However, it has been progressively displaced from food. This plant is normally neither cultivated nor commercialized. The leaves are almost 15 cm long in the large specimens; the highest on the stem are lanceolate and the lowest on the plant are oval.
The fruit is a capsule less than 2 mm long with an opening that, when opened, contains a small black seed. In English it is known as pigweed because of the plant's tendency to sprout where pigs are fed grass. Both the leaves and the seeds are edible.
It is part of the 75 species of the genus Amaranthus. This is usually thought of as pseudocereal. Its seeds contain starch but it does not belong to the same family as cereals such as wheat and rice.
Nutrients
Plants that are recognized as true cereals are monocotyledonous plants. Plants such as amaranth, quinoa, buckwheat, buckwheat, and millet are dicotyledonous, not grassy.
They are usually grouped under the term «pseudocereals», even though it has not been properly defined to date in the literature.
Due to their chemical composition, the seeds of these plants are used for human nutrition, just like cereal grains. They contain high levels of protein and the amino acid lysine, which is usually deficient in most cereals.
In the case of pigweed, not only are the seeds edible, so are the leaves. These are mainly made up of water (88%), carbohydrates (3%), fiber (3%), proteins (3%) and less than 1% fat.
In its composition are present folic acid, iron, calcium, carotenoids, vitamins A, B2 and C and phytochemical compounds. The red stems are rich in iron. It is recommended to consume the 4 or 6 upper leaves of the stem. Those of the base are rich in oxalate, they are woody and bitter.
Eight Amaranthus retroflexus L compounds have been identified, isolated and purified. These include a sphingolipid, two flavonoids, four sterols, and an amino acid.
The seed contained in the spike is very small, about 1 mm in diameter, and is rich in lysine. It is also a source of minerals such as phosphorus, magnesium, potassium, iron, zinc and copper, and of significant amounts of carbohydrates and proteins.
There is a large amount of nitrate in the organs of A. retroflexus. The stem and branches are the main storage organs for nitrates.
The nitrate absorption rate increases with the aging of the plant. The high absorption and storage capacity of nitrate would be an important factor for the species to compete successfully against cultivated plants.
Indeed, it is the nitrogenous compounds that generally limit plant production. Both these and carbohydrates fluctuate throughout the growth period.
In general, when carbohydrates are high, nitrogen compounds are low, and vice versa. This inverse relationship is due in part to the synthesis of protein, chlorophyll, phospholipine, and other organic nitrogen compounds at the expense of soluble carbohydrates.
The predominant sugars in the seeds are polysaccharides. These make up almost half of the total dry weight of the seeds. The seeds contain phosphatides and phytosterol is also present.
Health properties
- The seeds are used for their antioxidant, antiparasitic and healing properties.
- The tea prepared with the leaves is astringent and calming. It is used as a poultice to relieve inflamed sores.
- In bathrooms it is used to calm fever.
- It has been used in infusion to treat aphonia.
- It is used in the treatment of heavy menstruation, intestinal bleeding, diarrhea, etc.
- The piglet helps regulate intestinal transit. Its potassium content gives it diuretic and cleansing characteristics. In this way, it intervenes in the body's detoxification processes.
Forms of consumption
It is grown as a vegetable. The flavor of the leaves is reminiscent of green tomato. The leaves can be eaten raw, boiled or fried, as if they were spinach.
Pigtail is consumed in many parts of the world as just another vegetable. You can make an omelette with eggs and milkweed, or stew it with rice and legumes, in cream or milkfish croquettes.
It is used in the Indian state of Kerala to prepare a popular dish known as thoran, combining the finely cut leaves with grated coconut, chili peppers, garlic, turmeric, and other ingredients.
On the other hand, one way to neutralize the oxalates present in piglet is to eat it together with cheese.
The seeds can be eaten raw or roasted. Ground into powder can be used as a cereal substitute.
They are used to make breads, as a cereal to make a hot atol or as a thickener. If they are roasted before grinding them, their flavor improves markedly, and sprouts can be added to salads.
Precautions related to its use and production
No species in the genus Amaranthus is poisonous. There are no data on the toxicity of Amaranthus retroflexus. However, like many other species of amaranth, it can be harmful and even fatal when fed to cattle and pigs in large numbers for several days.
People who are sensitive to oxalic acid should also not eat it heavily for long periods of time. Its high oxalate content can cause fatal nephrotoxicity.
If its consumption causes swelling, it may be a reflection of a high nitrate content. This is especially noticeable if the plant comes from soils fertilized with chemical fertilizers.
Nitrates are implicated in stomach cancers and other health problems. Therefore, it is advisable to eat the plant only if it comes from land without chemical fertilizers.
Administered moderately as forage it is considered exceptionally nutritious. It should be noted that pigweed is perceived by farmers as an aggressive and competitive herb in the field.
It produces a substantial loss of yield in soybeans, corn, cotton, sugar beets, sorghum, and many vegetable crops.
This plant shows resistance to changes in pH, salt content, the environment, temperature and drought, and has a high capacity for adaptation.
References
- Actions and programs / amaranth amaranthus spp (2017). Obtained from the National Seed Inspection and Certification Service: gob.mx
- Alegbejo JO Nutritional value and utilization of Amaranthus (Amaranthus spp) - A review. Bajopas 2013 Jun; 6 (1): 136– 143
- Amaranthus retroflexus. (2018). Retrieved on April 2, 2018, from Wikipedia
- Amaranthus retroflexus. (sf). Retrieved on April 3, 2018, from pfaf.org
- Astiasarán Anchía I., Martínez Hernández JA (2003). Foods. Composition and Properties. Mc Graw Hill-Interamericana
- Bledos. (2018). Retrieved on March 31, 2018, from botanical-online
- Bledo-amaranthus retroflexus. (2018). Retrieved on March 30, 2018, from cistellaverda.wordpress.com
- Guil, JL, Rodríguez-Garcí, I., Torija, E. Plant Foods Hum Nutr. 1997 Sept; 51 (2): 99-107.
- Pigweed. (2018). Retrieved on March 30, 2018, from ediblewildfood.com
- Pigweed. (2018). Retrieved on April 2, 2018, from britannica.com
- Singhal R., Kulkarni P. Composition of the Seeds of Some Amaranthus Species. J. Sci. Food Agric. 1988 Aug; 42,325-331
- Woo, ML Chemical Constituents of Amaranthus retroflexus. Botanical Gazette. 1919 Nov; 68 (5): 313-344