Introduction

Dragon tongue beans are legumes with stringless pods. The scientific name is Phaseolus vulgaris and belongs to the Fabaceae family. Widely distributed in France, England, and America. It is a variety of young green beans that can be grown in home gardens as they are easy to grow and very less or no fertilizers are required. If grown in a favourable environment these beans are highly productive with good yield. These beans can be used as snap or shelled (1).

Maturation takes 55–60 days (2). The flower turns into beans in 12–15 days. The average temperature requires for seed germination is 15 ᵒC to 30 ᵒC. (3).

Common name

• Dragon tongue shelling bean
•  Snap bean
• Heirloom bush yellow wax dwarf bean
• Dragon lingerie
• Mervellie de Piemonte
• Meraviglia de Piemonte

 Synonyms

Phaseolus vulgaris

Appearance

It is a young green bean with seeds enclosed in a buffed colourful pod in the mottled burgundy pattern. These beans are green or pistachio green in colour and have a slightly curved shape. The average height of a fully grown plant is 2–3 feet approximately, the plant is generally in the bush or dwarf form. The pods (fruit) are flat and have purple stripes, fleshy and soft, therefore breaking easily. The flowers are purple in colour. Seeds are small and bright colours (1 & 3).

Nutritional value of Dragon tongue beans

Nutritional value per 132.8 g

 In addition to this they are rich in iron, vitamins A, C and K, selenium, calcium and folate.

The bioactive compound of Dragon tongue beans

The bioactive compounds present in the extract of dragon tongue beans are flavonoids, terpenoids, anthraquinones, carbohydrates, proanthocyanidin, polyphenols etc (4).

Medicinal benefits

They are a rich source of proteins, phenolic compounds, flavonoids, and amino acids and have nutritive properties, therefore it is used as traditional medicines globally. The compounds extracted from the phenolic extract help to reduce the chances of cardiovascular diseases and cancer diseases.

Also have great antioxidant and anti-inflammatory activity, therefore used as dietary supplements to promote good health (4).

Dragon tongue beans Benefits

1. Antioxidant activity

The extract of dragon tongue beans contains bioactive compounds that help to inhibit the activity of free radicals to prevent cell damage. The peels of these beans show antioxidant activity with a reducing power low IC₅₀ value of 88.37 μg/ mL (4).

2. Reduce cholesterol level

The proteins isolated from the extract of dragon tongue beans help to reduce cholesterol levels and blood glucose levels, therefore it regulates the effect of diabetes (4).

3. Cytotoxicity activity

The extract of beans shows the inhibitory effects against the cell viability percentage of HepG₂ cancer cells. It was evaluated that the different concentrations of Dtbp – AgNPs have different cytotoxicity effects on cancer cells.

There is a gradual decrease in the viability of cancer cells with an increase in the concentration of Dtbp – AgNPs. The cytotoxicity potential is high with a low IC₅₀ value of 37.02 μg/ mL (4).

4. Anti-diabetic activity

The Dtbp – AgNPs show great potential as an anti-diabetic substance with a low IC₅₀ value of 1. 98 μg/ mL. Dtbp – AgNPs bind with the α- Glucosidase enzyme and α- amylase enzyme and inhibit its activity and control the blood glucose level, which helps to control diabetes (4).

Side effects of Dragon tongue beans

There is no serious side effect of consuming dragon tongue beans. In some cases, if these beans are consumed in excess it may cause indigestion with stomach pain.

Edibility

It can be eaten raw as well as cooked. The young beans can be eaten raw, while the matured ones need to be cooked.

 How to cook Dragon tongue beans

Dragon tongue beans can be boiled, baked, stir-fried or steamed in a pan.

Dragon tongue beans curry

To make dragon tongue beans curry, seeds as well as the whole pod are used. Cut the beans into small pieces.

In a pan put 2 tablespoons of butter, heat it and add 1 finely chopped onion, ½ tablespoon of cumin seeds, 2-3 finely chopped green chilly and 3-4 pieces of garlic, cook these ingredients for 3-5 minutes.

Now add the 2 cups of beans, seeds and salt (as per requirement) mix it well and cooked it for 5-10 minutes.

Add 3 cups of water and cooked it at medium flame for 5-10 minutes. Garnish the curry with coriander leaves and serve it.

Q&A

1. How to cook dragon tongue beans?

To make dragon tongue beans, first, clean the beans with cold water. Now in a pot pour water (half filled) and boil it, now in boiling water add the beans and let it boil for a few minutes. Wash the beans under cold water. You can now saute the beans or can prepare the delicious curry.

2. How to eat dragon tongue beans?

It can be eaten raw as well as cooked. The young beans are smaller and soft that can be eaten as snap peas or can be cooked just like green beans.  You can also dry the mature beans and use them for preparing salad, soup or any other dish. The dried beans can be stored in a storage container for long-term uses.

3. What do dragon tongue beans taste?

They are slightly sweet and juicy in flavour.

4. Dragon tongue beans how to eat?

Both bean pods, as well as seeds, are edible. When the beans are young they are soft hence they can be eaten raw.

The matured beans are cooked as green beans. It can be used for many preparations it can eat as a salad, used as stuffing for sandwiches, mix it with mushrooms, or simply sauteed the seed of beans in oil with cumin seeds, salt, and a pinch of black pepper and serve this crunchy bean seeds as a side dish with bread or any other preparation.

5. How to plant dragon tongue beans?

Ans. It can be grown easily in the home garden or any suitable land where there is a proper arrangement of drainage and sunlight is available. Soak the seeds of the bean overnight, then directly sow the seeds in the soil (depth 1’’) in a row with 1–2 feet of space between them. Water these sowed seeds regularly for fast germination of seeds.

The seeds will germinate within 1-2 weeks of sowing. These beans require very less fertilizers for their better growth. Once the seeds germinate and the plant starts growing keep these plants protected from the pest. If a favourable environment is available to the plants the beans are produced with high yield.

Written By: Neetu Ladiya