A fair amount of literature has sprung up on the cultivation, properties and use of the soya bean, and Shri F. S. Kale, Food Survey Officer of the Baroda State, has written an exhaustive book on the soya bean* which is a kind of compendium on the subject of its cultivation and use.
The readers of Harijan know very well by now that the soya bean is the richest of all beans in proteins and fat and fat-soluble vitamins, and also know something of the experiments we made with the bean here in Maganwadi. Perhaps we were little fitted to pronounce upon the dietetic value of the bean, for in spite of our claim to do manual labour we are in no sense of the word manual labourers, and the bean is pre-eminently of use for those who labour hard with their hands and feet and those of our poor who cannot afford milk and ghee. A bean rich in proteins and fat is hardly the food for those with sedentary habits, but it is an effective article to supplement the defective dietaries of India, and added in proper proportion to wheat-flour it is good for all. Unfortunately, we in India, neither Government nor public bodies, have made anything like experiments worth the name and have to fall back on results obtained in foreign lands. Sjt. Kale says that there is a Soya Bean Research Institute at Moscow and that as part of the 'Five Year Plan', Russia has set aside vast tracts of land for its cultivation. "An exhibition of Soya bean food," says Sjt. Kale, "was held where 300 varieties of soya bean dishes were prepared including cake, pastry, salads, biscuits, chocolates, toffee, tea, coffee, cutlet, meat substitutes, soup, etc. It was served to the representatives of trade union factories, engineers, Soviet Press, and the Red Army. The food was unanimously pronounced to be excellent." "Studies," he adds, "made by Osborne at Barbara's Hospital show that after a meal of soya bean the alkalinity of the blood is increased." Soya bean food neutralizes the acidity in the blood. It is very important from the medical point of view as the normal alkaline state is the state of highest health and physiological functioning while the acid state is a pathological condition. Protein from meat increases the amount of uric acid in the system and thus creates rheumatism, kidney troubles and gout. The protein from soya bean on the other hand neutralizes uric acid and does not produce any disease. It is said that gout is unknown in China. "It was found at the laboratories of Dr. Sherman, Professor of Food Chemistry at Columbia University, that the proteins of the meat and fish as well as eggs and grains are acid- producing while those of the soya bean are alkalizing in their effects." This would point to the value of the soya bean as an effective substitute for meat food.
The chapter on the cultivation of the soya bean is of great practical value, inasmuch as it is based on experiments made by the only State in India - the Baroda State — on a considerable scale. It can be sown in any season and is a summer as well as a winter crop, care being taken to sow it after monsoon where rainfall is excessive, and to sow it in the monsoon where the rainfall is from 30 to 50 inches. The author describes in detail experiences of individual cultivators in Baroda and C.P., which should be of great help to intending cultivators of the bean. It is regarded as a useful agent for improving the soil, as it transfers the nitrogen taken from the air to the soil and makes it rich and fertile, and as a livestock feed it is supposed to be of great value. Says Sjt. Kale: "Soya bean hay is very nutritious as a livestock feed on account of its high content of digestible nitrogen. The comparative feeding tests carried on in America with clover, alphafa, cowpea and lucern show the superiority of soya bean fodder to all other in point of production of milk and butter. It has been our experience that cows give more milk and put on more weight when fed on soya bean hay. It has been found at the Baroda agricultural experimental station that the bullocks showed great strength and agility and put on more weight when they were fed on soya bean hay.
As an article of diet I have already spoken about it. There are two or three things which are worth noting as of general interest. There is no doubt about the very high protein-value of the soya bean, and it is, therefore, a very valuable article of diet for those who do hard manual labour. But we are apt to exaggerate this value. One has to take into consideration the biological value of its protein in comparison to that of the proteins of other articles of food. Thus the biological value of the soya bean protein according to Dr. K. P. Basu is 56 (taking the value of milk protein as 100), that of fish protein is 98 and meat protein is 105 and according to Dr. Aykroyd that of the soya bean protein is 64, of egg 94, of whole milk 84 and of rice 65. Dr. Aykroyd is definitely of opinion that "soya bean protein, when fed as the sole source of protein in the diet, is definitely inferior in biological value to milk and egg proteins, but human diet usually contains a variety of protein derived from different foods and there is evidence that soya bean protein can efficiently supplement cereal proteins. On the practical side my own opinion is that soya bean is a valuable food, when used in comparatively small quantities to supplement the largely cereal diets in India." Sjt. Kale, who is also a food expert, emphasizes the value of the bean as a supplement to wheat flour (15 to 20 per cent only to be added), as it is particularly rich in fat, mineral salts and vitamins. General Sir Robert McCarrison advocates "the use of 'soya bean milk' for infants and young children, who cannot obtain a sufficiency of mother's or cow's or other milk", and Sjt. Kale gives the photograph of his own baby who was fed on soya bean milk, with great success, for nearly two months. But for an authoritative pronouncement experiments carried on over an extensive area and for a sufficient period are necessary'- What Sjt. Kale says about the capacity of soya bean flour to improve the quality of our chapati or roti seems to be highly likely: "Soya flour will enhance the nutritive quality of Indian rot is. Less ghee or oil will be required, as there is 20 per cent of fat in soya flour. The palatibility of roti will be much better than the ordinary roti. The texture and the colour of roti will improve. The keeping qualities of roti will improve, and it will last for a longer time without being spoiled. By adding soya flour 15 to 25 per cent to our ordinary roti it will not only improve in nutritive quality, but it will also improve in digestibility. There will also be a saving of oil and ghee on account of the sufficient fatty content in soya flour. It will keep roti or chapati soft."