Devajyoti Bokolial, who teaches botany at St Anthony’s College, on the nutritional aspects of the ubiquitous grass
BAMBOO SHOOT is a popular vegetable not only in our state, but among the ethnic groups of most of the Asian countries. In recent times it is gaining popularity even in western countries. The tender bamboo shoots are considered a great delicacy. These are consumed fresh as vegetable or after drying or roasting or fermenting. They are also eaten as salad or pickle.
Bamboo shoots in different forms are used in hundreds of mouth watering traditional cuisines in different countries. Besides India, in countries like China, Japan, Thailand, Vietnam, Indonesia, Korea, Philippines and Nepal, bamboo shoots are extensively used in different recipes and are quite popular. In China and Japan bamboo shoots are called as ‘Sunjian’ and ‘king of the forest vegetables’ respectively and considered as highly nutritious. ‘Kharisa’ in Assam, ‘Soibum’ in Manipur, ‘Kardi achar’ and ‘kardi baja’ in Orissa, ‘Alu-tama’ in Nepal, ‘Takenoko gohan’ in Japan, ‘Labong’ in Philippine, ‘Gulai rebung’ in Indonesia are just few items prepared from bamboo shoots.
Nutritional profile of bamboo shoots reveals a number of health benefits. It contains very low amount of carbohydrates, negligible amount of fats and zero cholesterol, thus an excellent food for those who want to reduce weight. Protein from bamboo shoots contains all the essential amino acids besides non essential ones. Amount of dietary fiber is very high in bamboo shoots which increases appetite, reduces constipation and lowers the risk of colon-rectal cancer. It also contains vitamins A, C, E and majority of the vitamins of B1 complex. About 10 different minerals are present in bamboo shoots; among them amount of copper, manganese and potassium is very high. High potassium content (533 mg/100gms fresh shoot) helps in keeping blood pressure normal and also good for heart. Presence of vitamins and minerals helps in strengthening overall immune system.
Bamboo shoots also have some medicinal uses. Ancient ayurveda believes extracts of bamboo to have anti-venomous properties. They are also used in respiratory diseases. In traditional Chinese medicine, they are used for uterine contractions. Researchers also established its anti-inflammatory and cooling properties.
Though bamboo shoots offer an array of health benefits, utmost care should be taken while consuming them. Scientists have reported the presence of a cyanogenic glycoside called ‘taxiphyllin’ which is converted to hydrogen cyanide. When consumed, cyanide can be released inside our body which is extremely toxic.
A fresh bamboo shoot may contain up to 1000 mg/kg of hydrogen cyanide which varies according to species and varieties. Level of taxiphyllin also depends on the stage of harvest; too young and over-matured shoots generally contain very high level of this compound. World Health Organisation and Food and Agriculture Organisation recommended ADI (acceptable daily intake) value for cyanide is 0.05 mg/kg of body weight/day. However, post harvest processing generally removes most of the cyanides. Boiling the fresh shoots in salted water for a period of minimum 20 minutes removes about 91% of the taxiphyllin as they are easily degraded in boiling water. Level of cyanide also drops in fermented shoots.
Thus properly processed bamboo shoots are free from the danger of cyanide toxicity and can be consumed as a healthy food.