Tengnoumanbi - An essential food item eaten raw or cooked by the Manipuris

Dr Nameirakpam Irabanta Singh *

Tengnoumanbi - Manipuri food items found available in a Sunday Market in Malaysia :: Pix - Dr Yumnam Jayanta

Tengnoumanbi/Winged bean [Botanically known as Psophocarpus tetragonolobus (L)DC order Fabales, Family- Fabaceae] is a tropical legume plant, native to New Guinea.

Range, Habitat and Germination

Winged bean grows abundantly in the hot humid equatorial countries of South and Southern Asia. In South East Asia and Papua New Guinea, it is widely recognized by farmers and consumers in Southern Asia including Myanmar and Manipur for its uses and disease resistance.

Although winged bean thrives in hot weather and favours humidity, the plant’s ability to grow in heavy rainfall makes it as food for African tropics. Its production is optimal in humidity but the species is susceptible to moisture stress and water logging. Ideal growing temperature is 25ø C.

As such, it is suitable in Manipur valley condition. Lower temperature suppress germination and extremely high temperature inhibit yield. Although the plant is tropical, it can flourish in a dry climate if irrigated. If the plant matures during the drier part of the growing season, yields are higher.

Winged bean can grow at least as fast as comparable legumes including soybean. Plants flower 40 to 140 days after sowing. Pods reach full length about 2 weeks after pollination. Three weeks after pollination, the pod becomes fibrous, after six weeks mature seeds are ready for harvest.

The winged bean is a tropical plant and will only flower when the day length is shorter than 12 hrs, although some varieties have been reported to be day neutral. Winged bean can be grown without added fertilizer as the plant has a bacterium on the nodules of the roots that fixes nitrogen and allow the plant to absorb nitrogen.

Structure

Tengnoumanbi grows as a vine with climbing stems and leaves, 3-4m in height. It is a herbaceous perennial but can be grown as an annual. It is generally taller and notably larger than the common bean. The bean pod is typically 15-22 cm (6-8.5m) long and has four wings with frilly edges running lengthwise. The skin is waxy and the flesh partially translucent in the young pods. When the pod is fully ripe, it turns as ash brown colour and splits open to release the seeds. The large flower is a pale blue.

The shape of its leaves ranges from ovate to deltoid, ovate-lanceolate, lanceolate and long lanceolate. The stem, most commonly, is green but sometimes boasts purple. The pods are usually rectangular, but appear flat. Pod may be coloured green, pink or purple. Seed shape is often round, oval and rectangular seeds also occur. Seeds may appear white, cream, dark tan or brown, depending on growing and storage conditions.

Mode of consumption

The tender winged bean pods/ Tengnoumanbi Mahei are most widely eaten part of the plant by the Manipuris and best when eaten before they exceed 2.5 cm (1.00 inch) in length. The tender pods are taken as raw along with morok metpa [ thick sauce made from red chilies and roasted ngari( fermented fish) or singju (sliced winged bean pods, thangjing i.e Euryle ferox meshed with thick sauce made from red chilies and roasted ngari/fermented fish].

It is also taken as iromba made from boiled winged bean pod, chu-chu rangmei (Sesbania sesban), Thangjing( Euryle ferox) and Ekai thabi (Neptunia prostrata) meshed together in a sauce of chilly paste, salt and roasted ngari (fermented fish) or fermented soybean for vegetarian. It can also be served with a combination of sliced onion, coriander leaves as garnish.

Nutritional value

The entire winged bean plant is edible. The leaves, flowers, roots and bean pods can be eaten raw or cooked; the pods are edible when raw and unripe. The seeds are edible after cooking, each of these parts contains Vitamin A, Vitamin C, Calcium and among other nutrients.

The nutritional value for 100g Winged beans, mature seeds contain energy (1,711 KJ/409 K Cal), carbohydrate(41.7g), fat(16.3g), protein(29.65g), vitamin[ Thiamin(B1)-1.03mg; Riboflavin(B)-0.45 mg; Niacin(B3)-3.09mg; Pantothenic acid(B5)-0.795mg, Vitamin B6-0.174mg; Folate(B9)-45mg ; minerals-( calcium-440mg; iron- 13.44mg; magnesium-129mg; manganese-3.72mg; phosphorous-451mg; potassium-977mg; sodium-38mg and zinc 4.48 mg)].

Discussion

Tengnoumanbi/Winged bean is a rapidly increasing interest as a high protein multipurpose crop, particularly for cultivation in humid tropics soils, where the nitrogen and phosphorus usually limit plant production. The exceptional ability limits plant production. The exceptional ability of the crop is to fix atmospheric nitrogen by bacteria in the root nodules should not be overcooked in view of the world shortage and rising prices of artificial nitrogen fertilizers.

It has been suggested that in future the winged bean could become as important as soybean in the world agriculture, with the added bonus as N2 fixing legume which could replace the need for N fertilizer by actually adding N to the soil. The rich protein content of the all plant parts is due to abundant nodulation and consequent high rate of nitrogen fixation of Psophocarpus tetragonolobus. Besides, all parts of the plant are edible. The plant is used as food, animal feed, pesticides and medicinal uses.

The seeds, which are very similar to nutritionally to soybean have the advantage that they have a pleasant sweet flavour of the soybean. Like the soybean, the winged bean could be utilized as a source of edible oil and has potential as a substitute if commercial production could be developed. Another interesting feature of the crop is the high protein content of the root tubers which could help alleviate protein deficiency in Manipuri diet.

Economies of Tengnoumanbi

At the beginning of June-July, the cost of 10(ten) pods bundle of winged bean at Khwairamband keithel, khurai keithel, Singjamei keithel are Rs 10/-. During September-October, a lumsum amount of 30 pods cost Rs 20/-. The Winged bean pods are sold in the keithel of Imphal valley as lumsum cost of Rs 40-50 per one Kg.

Beauty benefits of Winged bean

Consuming healthy winged beans regularly can give our self a boost tool. Here are some of the beauty benefits of winged beans. It includes-
i) prevents premature ageing,
ii) maintains skin elasticity.

The high dose of antioxidant present in winged beans ensures that the skin maintains its elasticity and keeps it looking young.

Conclusion

The winged bean is an underutilized legume species in Manipur but has the potential to become a major multi use food crop.