Meat Equivalent for Vegetarians
Meat Equivalent for Vegetarians
By Dr K. C. Kanwar
The Tribune, Chandigarh, India
Wednesday, November 25, 1998
PULSES, also termed legumes or beans, are podded seeds of leguminous plants. Beans is a collective term applied to the tender edible pods as well as used for the seeds of various such plants. Many varieties of beans are grown exclusively for their tender pods to be used as green vegetable, e.g., the French beans, string beans and “lobia”. These are profitably grown only in places where the growing season is long enough to permit repeated pickings. Otherwise, beans are cultivated for their fully grown seeds which are either used fresh (green peas) or dried (e.g. dried peas, Bengal grams, chickpeas, navy and lima beans, varied lentils and pulses).
There are approximately 2000 known legume plants that produce the edible seeds variedly known as beans, lentils, pulses, grams etc. Many a time these terms are used synonymously. Dried beans display a bewildering variety of colours – from uniformly dark-brown, green, creamy-white or inky-blacks to varyingly stippled and speckled with fast colours. Pulses (the Indian equivalent – dal) also known as grain legumes , belong to the genus Phaseolus and are grown as field crops. The major pulses grown the world over comprise the field peas, chickpeas, fabia beans, lentils, lupins and perhaps many more.
In India the most common pulses are moong, urad, masoor, rajmah, lobia and rongi, which are consumed either as whole, split, dehusked and in certain cases even in powdered form such as besan. Many pulses, when appropriately processed, make the choicest snacks. Pulses can be profitably fractionated into three components viz. fibre, starch, proteins and these can be added at will to fortify many of the processed food products. The use of pulses as snacks and high-protein food or in pasta has a lot of scope to flourish.
Pulses are grown in rotation with cereals and oilseeds to improve soil fertility. The suitability of land for the production of pulses varies with soil types and average annual rainfall. These grow well even in poor soils. They are better suited to alkaline soil except lupins which perform better in acidic one. Many a time, the beans are cultivated simply to enrich soil since these plants have the unique property of taking up nitrogen (the essential plant nutrient) from air with the help of nitrogen-fixing bacteria lodged in their root nodules, and add this to the soil where it serves as a fertiliser.
Pulses, earlier in the developed world, were mainly used in the stockfeed industry. But not any more. Of late, the use of these in the food industry is increasing rapidly owing to their unique nutritional attributes and increasing consumer awareness. The world demand for pulses is increasing every year because these constitute an affordable rich source of protein, especially in the underdeveloped and developing world. The adoption of low-fat diets and the ever-growing tilt towards vegetarianism in the West, it is felt, will further escalate the demand for pulses globally.
According to the current estimates dry beans or pulses are a healthier and less expensive source of proteins for over two billion people worldwide. Beans are nutritively crucial for those who are habitually or compulsively vegetarians. For them, these constitute the meat equivalent.
Pulses/beans have all the plus points of providing healthy and nutritious food. They are rich in the much-needed proteins, low in fat and high in complex carbohydrates. They constitute a good source of minerals.
These contain high levels of resistant starch and the much needed fibre which tend to suppress appetite and hence their relevance in weight control programme. A diet rich in pulses ensures the desired supply of the fibre which in turn, lowers blood cholesterol – the main-villain of cardiovascular diseases – and helps fight colon cancer. The soluble fibre in the beans also helps maintain constant blood sugar levels – a boon for the diabetics.
According to Patti Geil of Kentucky University, a cup of boiled beans a day actually lowers the blood cholesterol level by an average of 10 per cent. Also low-fibre pulses like dehusked moong are extremely useful in providing adequate nutrition during convalescence and after a bout of diarrhoea when patients need easily digestible yet nutritious food.
The bean proteins, though abundant, are rated somewhat inferior in quality; these are particularly low in sulphur-containing amino acid methionine. Fortunately, methionine is found in plenty in the cereals (wheat and rice) which lack lysine – the amino acid abundant in pulses. Pulses, when consumed along with cereals make good the deficiency of each other through mutual supplementation. Dal-roti – a basic dietary concept of the poor in India – is a healthful combination though bereft of vitamins.
The nutritive value of the pulses or beans can further be improved, if these are allowed to sprout before being used as salad; sprouted beans are less calorific and far more nutritious than before. Sprouting (germination) tends to improve immensely their digestibility. The sprouts almost instantaneously acquire a battery of enzymes capable of breaking down proteins into amino-acids, starch into simple sugars and fats into fatty acids rendering them more easily digestible and assimiable.
The sprouts are excellent to those trying to slim down and lose weight. For example in the sprouted moong, the overall energy decreases by 15% but the protein availability increases by a whopping 30%. The carbohydrate molecules during sprouting are broken down and these, when they react with nitrogen, go to form amino-acids which, in turn, give rise to easily digestible proteins.
During sprouting, the trypsin inhibitors, which are commonly present in the raw pulses and impair their digestibility, are also inactivated. Further vitamins (A, B-Complex, C) are also rapidly synthesised during germination and, therefore, increase. In moong sprouts the vitamin A content increases by 285%, thiamine by 208%, riboflavin by an astounding 515%, niacin by 256% and finally ascorbic acid by 600%. When the seeds sprout, shoots appear earlier than roots. The sprouts are maximally nutritious, if consumed before the roots start emerging.
Sprouts are considered an excellent and inexpensive substitute for expensive fruits since both are rich in fibre and vitamins. Sprouts are also a rich source of assimiable minerals such as calcium, magnesium, phosphorus, potassium and zink. In moong sprouts, the availability of calcium increases by 34%, potassium by 80%, iron by 40% and phosphorus by 56%. This is attributable to the release of minerals from protein complexes and decrease in the level of phytates during sprouting. Further, beans like fruits, are low in sodium and high in potassium which in particular render them health-friendly and ideal for the hypertensive.
All this establishes the usefulness of sprouted beans in the menus. Sprouts should preferably be eaten either raw or following brief steaming lest they lose much of the vitamins. The seeds, more suitable for sprouting comprise kala chana or moong and certain other lentils.
Nutritionally, beans bring with them as much, if not more, protein as meat for much fewer calories and no artery-blocking fat and cholesterol. On an average, 27% of the calories in beans come from proteins and only 6% from fat as against beaf steak in which 20% of the calories come from proteins and 72% from fat. Compared to cereals which contain 7-12% proteins, pulses contain about 20-30% proteins. In soyabean, the protein content is as high as 40%. Whole pulses are more nutritious than their corresponding split dehusked forms.
Cooking, especially of big beans, is very time-consuming, particularly if these are not soaked overnight. Pressure-cooking is unavoidable especially at higher altitudes. Hard water should be avoided for boiling beans since it delays their softening necessitating prolonged boiling. Keep off tomatoes or anything acidic like tamarind and raw mango powder (amchur) until the beans are fully boiled and tender. Acidic pH of the cooking medium toughens the cell walls which retards the softening of the beans. The cooking time of the hardly beans can be cut down considerably by adding a small dash of baking soda which renders the cooking water alkaline, which accelerates the softening of the beans. However, baking soda, if used in excess, destroys vitamins of the B-group, especially thiamine, and hence should be avoided.
Many people prefer to avoid beans. These are known to produce gas. Beans, after all, are seeds rich in indigestible sugars which serve as the reserve nourishment for the seed at the time of germination. These complex and indigestible sugars comprise alpha galactosidases which humans cannot digest. However, this component, when it passes through the lower intestine, is broken down with the help of bacteria residing in the colon and in the process gases (methane and carbon dioxide) are produced.
The dietetics have developed a technique to take away flatulence of the beans. Soak the beans overnight and boil the same for about five minutes, turn off the heat and let these be further soaked for a few more hours. Discard the water and with this are discarded the indigestible gas-producing sugars. Boiling softens the seed cell walls which allow the offending sugars to leach out.
A single round of boiling and soaking removes approximately 85% of the offending component thus spelling relief for the users. Boiling and then discarding the boiled water do result in leaching out of some nutrients, for example the skin pigments, and minerals. Allowing such a loss is perhaps the lesser of the two evils, the scientists feel. The loss of minerals get easily compensated from other dietary sources. Proteins and fibre for which the beans are primarily preferred are not destroyed by such a procedure.
Dr Kanwar is a former Professor and Chairman of the Biophysics Department of Panjab University.