Effects of partial replacement of rice, wheat or ragi (Eleusine coracana) by tuber flours on the nutritive value of poor vegetarian diets.

Consequent on the present shortage of rice and other cereals both in India and in other parts of Asia, it has become increasingly necessary to make up the deficit of starchy foods from other sources. The most promising sources are roots and tubers like tapioca and sweet potato which give two to three times higher yields of calories per acre than the commoner cereals. In fact, in Travancore and certain other parts of southern India, tapioca already forms a substantial part of the diet of the people. Tapioca and sweet potato, however, are deficient in proteins, and by themselves can serve mainly as sources of energy. In an earlier publication from this laboratory (Murthy, Swaminathan & Subrahmanyan, 1950) it was reported that in experimental animals: (I) poor diets, based mainly on tapioca or sweet-potato flour, did not support life; (2) addition of groundnut-cake flour at a level of 20 yo to these diets enhanced the nutritive value of the diets to an even higher level than that of rice diet; and (3) replacement of rice in a poor rice diet to the extent of 25 yo by a mixture of four parts of tapioca flour and one part of groundnut-cake flour produced a marked improvement in the nutritive value of a rice diet. Further systematic studies were therefore undertaken with a view to confirming the above findings, and to find out whether similar beneficial results could be obtained with other cereals. At the same time, it was considered to be of some practical importance to investigate the effect on the nutritive value of the rice diet of replacing varying percentages of rice by tapioca flour.