Mung Bean

The mung bean is a bushy annual legume, usually 30 to 100 centimetres tall, with trifoliate leaves, small yellow flowers and slender pods that turn black or brown when ripe. Each pod holds about 10 to 15 small, oval seeds, most often olive-green, though yellow, brown and black types exist. The seed has a mild, slightly sweet, earthy flavour and cooks quickly without soaking. Mung beans are sold whole with the green skin, split with the skin on or hulled to yellow split dal, as flour, starch for glass noodles, and as fresh sprouts, which are eaten crunchy in salads and stir-fries.

The mung bean was domesticated in India, where archaeological finds suggest cultivation going back at least four thousand years, and wild forms still grow in parts of the subcontinent. From there it spread to China, South-East Asia, and later to Africa, Australia and the Americas. The name mung comes from the Hindi moong, derived from Sanskrit mudga. The species name radiata refers to the way the pods radiate from the stem like rays.

Mung beans have been grown in India since antiquity and are mentioned in ancient Sanskrit texts, where mudga is listed among the pulses used in food and medicine. They travelled along trade routes to China, where they are used in soups, desserts and sprouts, and to South-East Asia, Korea and Japan. Their rapid growth, taking as little as 60 to 90 days, and ability to fix nitrogen in the soil made them valuable in rotations with rice and wheat.

In India, moong dal remains an everyday protein in regional dishes such as khichdi and pesarattu. In East Asia, mung bean starch is made into transparent noodles and jellies, and the beans are boiled into sweet soups served in summer. In the twentieth century, mung bean sprouts became popular in Western countries through Chinese restaurants and the health-food movement. India is the largest producer and consumer, with Myanmar, China and parts of East Africa also important growers.

Whole mung beans are boiled into soups, curries and porridges, and sweet beans are cooked with sugar into desserts and fillings for pastries and mooncakes. Hulled split mung dal is the base of khichdi and many Indian dals. Flour is used for batters, crepes and flatbreads, and the starch is made into cellophane noodles. Sprouts are eaten raw or lightly cooked in salads, stir-fries and spring rolls. In some places the plant is also grown as green manure, forage and a cover crop.

Dry mung beans are a good source of plant protein, fibre, folate, iron, magnesium and potassium, and are generally considered easy to digest compared with some other pulses. Their polyphenols, such as vitexin and isovitexin, have been studied for antioxidant activity in the laboratory. As with other pulses, regular intake is associated with better blood sugar control and heart health in dietary studies, though evidence specific to mung beans is limited. Sprouting increases some vitamins and reduces anti-nutrients such as phytic acid.