Thelentil (Vicia lens orLens culinaris) is alegume; it is anannual plant grown for itslens-shaped edibleseeds, also calledlentils. It is about 40 cm (16 in) tall, and the seeds grow inpods, usually with two seeds in each.
Lentil seeds are used around the world forculinary purposes. Incuisines of the Indian subcontinent, where lentils are astaple, split lentils (often with their hulls removed) known asdal are often cooked into a thickcurry that is usually eaten withrice orroti. Lentils are commonly used instews and soups.
Many different names in different parts of the world are used for the crop lentil.[2] The first use of the wordlens to designate a specificgenus was in the 17th century by the botanistTournefort.[3] The word "lens" for the lentil is of classical Roman or Latin origin, possibly from a prominent Roman family named Lentulus, just as the family name "Cicero" was derived from the chickpea,Cicer arietinum, and "Fabia" (as inQuintus Fabius Maximus) from the fava bean (Vicia faba).[4]
The former genusLens consisted of the cultivatedL. culinaris and six related wild taxa. Among the different taxa of wild lentils,L. orientalis was considered to be the progenitor of the cultivated lentil and was generally classified asL. culinaris subsp.orientalis.[2]
Lentil ishypogeal, which means thecotyledons of the germinating seed stay in the ground and inside the seed coat. Therefore, it is less vulnerable to frost, wind erosion, or insect attack.[5]
The plant is a diploid, annual, bushy herb of erect, semierect, or spreading and compact growth and normally varies from 30 to 50 centimetres (12 to 20 in) in height. It has many hairy branches and its stem is slender and angular. Therachis bears 10 to 15 leaflets in five to eight pairs. The leaves are alternate, of oblong-linear and obtuse shape and from yellowish green to dark bluish green in colour. In general, the upper leaves are converted intotendrils, whereas the lower leaves are mucronate. Ifstipules are present, they are small. The flowers, one to four in number, are small, white, pink, purple, pale purple, or pale blue in colour. They arise from the axils of the leaves, on a slender footstalk almost as long as the leaves. The pods are oblong, slightly inflated, and about 1.5 centimetres (5⁄8 in) long. Normally, each of them contains two seeds, about0.5 centimetres (1⁄4 in) in diameter, in the characteristic lens shape. The seeds can also be mottled and speckled. The several cultivated varieties of lentil differ in size, hairiness, and colour of the leaves, flowers, and seeds.
Lentils areself-pollinating. The flowering begins from the lowermost buds and gradually moves upward, so-called acropetal flowering. About two weeks are needed for all the flowers to open on the single branch. At the end of the second day and on the third day after the opening of the flowers, they close completely and the colour begins to fade. After three to four days, the setting of the pods takes place.[2]
Types can be classified according to their size, whether they are split or whole, or shelled or unshelled. Seed coats can range from light green to deep purple, as well as being tan, grey, brown, black or mottled. Shelled lentils show the colour of the cotyledon which can be yellow, orange, red, or green.
Red-cotyledon types:
Nipper (Australia)
Northfield (Australia)
Cobber (Australia)
Digger (Australia)
Nugget (Australia)
Aldinga (Australia)
Masoor dal (unshelled lentils with a brown seed coat and an orange-red cotyledon)
Petite crimson (shelled Masoor lentils)
Red Chief (light tan seed coat and red cotyledon)
Small green/brown-seed coat types:
Eston Green
Pardina (Spain)
Verdina (Spain)
Medium green/brown-seed coat types
Avondale (United States)
Matilda (Australia)
Richlea
Large green/brown-seed coat types:
Boomer (Australia)
Brewer's: a large brown lentil which is often considered the "regular" lentil in the United States[6]
Castellana (Spanish)
Laird: the commercial standard for large green lentils in western Canada[7]
Mason
Merrit
Mosa (Spain)
Naslada (Bulgaria)
Pennell (United States)
Riveland (United States)
Other types:
Beluga: black, bead-like, lens-shaped, almost spherical, named for resemblance tobeluga caviar.[8] Called Indianhead in Canada.
Alb-Leisa three traditional genotypes of lentils native to the Swabian Jura (Alps) in Germany and protected by the producers' association Öko-Erzeugergemeinschaft Alb-Leisa (engl. "Eco-producer association Alb-Leisa")
In 2022, global production of lentils was 6.7 milliontonnes. Canada produced the largest share, 2.2 million tonnes, or roughly 34% of the world's total output (table),[9] nearly all (95%) of it inSaskatchewan.[10] India was the world's second-largest producer, led by the states ofMadhya Pradesh andUttar Pradesh, which together account for roughly 70 percent of the national lentil production.[11]
The cultivated lentilLens culinaris subsp.culinaris was derived from its wild subspeciesL. culinaris subsp.orientalis, although other species may also have contributed some genes, according toJonathan Sauer (Historical Geography of Crop Plants, 2017).[12] Unlike their wild ancestors, domesticated lentil crops haveindehiscent pods and non-dormant seeds.[12]
Lentil was domesticated in theFertile Crescent of theNear East and then spread toEurope andNorth Africa and the Indo-Gangetic plain. The primary center of diversity for the domesticLens culinaris as well as its wild progenitorL. culinaris ssp. orientalis is considered to be the Middle East. The oldest known carbonized remains of lentil fromGreece'sFranchthi Cave are dated to 11,000 BC. In archaeobotanical excavations carbonized remains of lentil seeds have been recovered from widely dispersed places such asTell Ramad inSyria (6250–5950 BC), Aceramic Beidha inJordan,Hacilar inTurkey (5800–5000 BC), Tepe Sabz (Ita.Tepe Sabz) inIran (5500–5000 BC) and Argissa-Magula Tessaly in Greece (6000–5000 BC), along other places.[13]
Lentils can grow on various soil types, from sand to clay loam, growing best in deep sandy loam soils with moderate fertility. A soilpH around 7 would be the best. Lentils do not tolerate flooding orwater-logged conditions.[3]
Lentils improve the physical properties of soils and increase the yield of succeeding cereal crops.Biological nitrogen fixation or other rotational effects could be the reason for higher yields after lentils.[14]
The conditions under which lentils are grown differ across different growing regions. In thetemperate climates lentils are planted in the winter and spring under low temperatures and vegetative growth occurs in later spring and the summer. Rainfall during this time is not limited. In thesubtropics, lentils are planted under relatively high temperatures at the end of the rainy season, and vegetative growth occurs on the residual soil moisture in the summer season. Rainfall during this time is limited. InWest Asia andNorth Africa, some lentils are planted as a winter crop before snowfall. Plant growth occurs during the time of snow melting. Under such cultivation, seed yields are often much higher.[14]
The lentil requires a firm, smoothseedbed with most of the previouscrop residues incorporated. For the seed placement and for later harvesting it is important that the surface is not uneven with large clods, stones, or protruding crop residue. It is also important that the soil be made friable and weed-free, so that seeding can be done at a uniform depth.[3]
The plant densities for lentils vary betweengenotypes, seed size, planting time and growing conditions, and also from region to region. In South Asia, a seed rate of 30 to 40 kilograms per hectare (27 to 36 pounds per acre) is recommended. In West Asian countries, a higher seed rate is recommended, and also leads to a higher yield. The seeds should be sown3 to 4 centimetres (1+1⁄4 to1+1⁄2 in) deep. In agriculturally mechanized countries, lentils are planted usinggrain drills, but many other areas still hand broadcast.[3]
A combination of gravity, screens and air flow is used to clean and sort lentils by shape and density. After destoning, they may be separated by a color sorter and then packaged.
A major part of the world's red lentil production undergoes a secondary processing step. These lentils aredehulled, split and polished. In theIndian subcontinent, this process is called dal milling.[3] The moisture content of the lentils prior to dehulling is crucial to guarantee a good dehulling efficiency.[3] The hull of lentils usually accounts for 6 to 7 percent of the total seed weight, which is lower than most legumes.[15] Lentil flour can be produced by milling the seeds, like cereals.
Lentils can be eaten soaked, germinated, fried, baked or boiled – the most common preparation method.[3] The seeds require a cooking time of 10 to 40 minutes, depending on the variety; small varieties with the husk removed, such as the common red lentil, require shorter cooking times (and unlike most legumes don't require soaking). Most varieties have a distinctive, earthy flavor. Lentils with husks remain whole with moderate cooking, while those without husks tend to disintegrate into a thick purée, which may enable various dishes. The composition of lentils leads to a highemulsifying capacity which can be even increased by doughfermentation in bread making.[16]
In theIndian subcontinent,Fiji,Mauritius,Singapore and theCaribbean, lentil curry is part of the everyday diet, eaten with both rice androti. Boiled lentils and lentil stock are used to thicken most vegetarian curries. They are also used as stuffing indalparathas andpuri for breakfast or snacks. Lentils are also used in many regional varieties of sweets. Lentil flour is used to prepare several different bread varieties, such aspapadam.
They are frequently combined withrice, which has a similar cooking time. A lentil and rice dish is referred to in Levantine countries asmujaddara ormejadra. In Iran, rice and lentil is served with friedraisin; this dish is calledadas polo. Rice and lentils are also cooked together inkhichdi, a popular dish in the Indian subcontinent (India and Pakistan); another dish,kushari, made in Egypt, is considered one of twonational dishes.
Lentils are used to prepare an inexpensive and nutritioussoup throughout Europe andNorth and South America, sometimes combined withchicken orpork. In Western countries, cooked lentils are often used in salads.[3] In Italy, the traditional dish for New Year's Eve isCotechino served with lentils.
Lentils are commonly eaten inEthiopia in a stew-like dish calledkik, orkik wot, one of the dishes people eat with Ethiopia's national food,injera flatbread. Yellow lentils are used to make a non-spicy stew, which is one of the first solid foods Ethiopians feed their babies.
Lentils were a chief part of the diet of ancient Iranians, who consumed lentils daily in the form of a stew poured over rice.
The low levels of readily digestible starch (5 percent) and high levels of slowly digested starch make lentils of potential value to people withdiabetes.[20][21] The remaining 65% of the starch is aresistant starch classified as RS1.[22] A minimum of 10% in starch from lentils escapesdigestion and absorption in thesmall intestine (therefore called "resistant starch").[23] Additional resistant starch is synthesized from gelatinized starch, during cooling, after lentils are cooked.[24]
Lentils also haveantinutrient factors, such astrypsin inhibitors and a relatively highphytate content. Trypsin is an enzyme involved in digestion, and phytates reduce thebioavailability ofdietary minerals.[25] The phytates can be reduced by prolonged soaking and fermentation or sprouting.[26] Cooking nearly completely removes the trypsin inhibitor activity; sprouting is also effective.[25]
Although lentils have been an important crop for centuries, lentil breeding and genetic research have a relatively short history compared to that of many other crops. Since the inception of TheInternational Center for Agriculture Research in the Dry Areas (ICARDA) breeding programme in 1977 significant gains have been made. It supplies landraces and breeding lines for countries around the world, supplemented by other programmes in both developing (e.g. India) and developed (e.g. Australia and Canada) countries. In recent years, such collaborations among breeders and agronomists are becoming increasingly important.[2]
The focus lies on high yielding and stable cultivars for diverse environments to match the demand of a growing population.[27] In particular, progress in quantity and quality as well as in the resistance to disease and abiotic stresses are the major breeding aims.[2] Several varieties have been developed applying conventional breeding methodologies.[28] Serious genetic improvement for yield has been made, however, the full potential of production and productivity could not yet be tapped due to several biotic and abiotic stresses.[27]
WildLens species are a significant source of genetic variation for improving the relatively narrow genetic base of this crop. The wild species possess many diverse traits including disease resistances and abiotic stress tolerances. The above-mentionedL. nigricans andL. orientalis possess morphological similarities to the cultivatedL. culinaris. But onlyL. culinaris andL. culinaris subsp. orientalis are crossable and produce fully fertile seed. Between the different related species hybridisation barriers exist. According to their inter-crossabilityLens species can be divided into three gene pools:
Crosses generally fail between members of different gene pools. However,plant growth regulators and/orembryo rescue allows the growth of viablehybrids between groups. Even if crosses are successful, many undesired genes may be introduced as well in addition to the desired ones. This can be resolved by using abackcrossing programme. Thus,mutagenesis is crucial to create new and desirable varieties. According to Yadav et al. other biotechnology techniques which may impact on lentil breeding aremicro-propagation using meristamatic explants, callus culture and regeneration, protoplast culture and doubled haploid production.[2]
There is a proposed revision of the gene pools using SNP phylogeny.[29]
^abSauer, Jonathan D. (2017).Historical Geography of Crop Plants: A Select Roster. Routledge.ISBN978-1-351-44062-2.The primary progenitor of the cultigen is evidentlyL. orientalis native to the Near East; the other species may have contributed some genetic diversity to the crop.L. culinaris (L. esculentus), the domesticate, differs from the wild species in having indehiscent pods, due to a single recessive gene, and nondormant seeds.
^abcShyam S. Yadav; David McNeil; Philip C. Stevenson, eds. (2007).Lentil: an ancient crop for modern times. Berlin: Springer Verlag.ISBN978-1-4020-6312-1.OCLC213090571.
^Zhang, Bing; Deng, Zeyuan; Tang, Yao; et al. (2014). "Fatty acid, carotenoid and tocopherol compositions of 20 Canadian lentil cultivars and synergistic contribution to antioxidant activities".Food Chemistry.161:296–304.doi:10.1016/j.foodchem.2014.04.014.ISSN0308-8146.PMID24837953.
^Ramdath D, Renwick S, Duncan AM (2016). "The Role of Pulses in the Dietary Management of Diabetes".Can J Diabetes (Review).40 (4):355–63.doi:10.1016/j.jcjd.2016.05.015.PMID27497151.
^Mudryj AN, Yu N, Aukema HM (2014). "Nutritional and health benefits of pulses".Appl Physiol Nutr Metab (Review. Research Support, Non-U.S. Gov't).39 (11):1197–204.doi:10.1139/apnm-2013-0557.PMID25061763.
^Kawaljit Singh Sandhu, Seung-Taik LimDigestibility of legume starches as influenced by their physical and structural properties Elsevier, 16 March 2007
^Tovar J (1996). "Bioavailability of carbohydrates in legumes: digestible and indigestible fractions".Arch Latinoam Nutr.44 (4 Suppl 1):36S –40S.PMID9137637.
^Johnson, Casey R.; Thavarajah, Dil; Thavarajah, Pushparajah; Payne, Scott; Moore, Jayma; Ohm, Jae-Bom (2015). "Processing, cooking, and cooling affect prebiotic concentrations in lentil (Lens culinaris Medikus)".Journal of Food Composition and Analysis.38:106–111.doi:10.1016/j.jfca.2014.10.008.
^abVidal-Valverde C, Frias F, Estrella I, Gorospe MJ, Ruiz R, Bacon J (1994). "Effect of processing on some antinutritional factors of lentils".J Agric Food Chem.42 (10):2291–2295.Bibcode:1994JAFC...42.2291V.doi:10.1021/jf00046a039.
^Egli, I.; Davidsson, L.; Juillerat, M.a.; Barclay, D.; Hurrell, R.f. (1 November 2002). "The Influence of Soaking and Germination on the Phytase Activity and Phytic Acid Content of Grains and Seeds Potentially Useful for Complementary Feedin".Journal of Food Science.67 (9):3484–3488.doi:10.1111/j.1365-2621.2002.tb09609.x.ISSN1750-3841.
^abKumar, Jitendra; Gupta, Sunanda; Gupta, Priyanka; Dubey, Sonali; Tomar, Ram Sewak Singh; Kumar, Shiv (2016). "Breeding strategies to improve lentil for diverse agro-ecological environments".Indian Journal of Genetics and Plant Breeding.76 (4): 530.doi:10.5958/0975-6906.2016.00071.7.ISSN0019-5200.
