The effect of supplements of groundnut flour or groundnut protein isolate fortified with calcium salts and vitamins or of skim-milk powder on the digestibility coefficient, biological value and net utilization of the proteins of poor Indian diets given to undernourished children.

The production of milk and other protective foods in many tropical and subtropical countries is inadequate to meet the needs of the population (FAO, 1959). The diets consumed in these countries are in general deficient in proteins, certain vitamins and minerals (FAO, 1959; Jelliffe, 1955). The problem of providing low-cost supplementary foods based on locally available protein-rich foods of vegetable origin has recently been engaging the attention of research workers (Subrahmanyan, Narayanarao & Swaminathan, 1960; Scrimshaw & Bressani, 1961) and also of international agencies (Autret & van Veen, 1955). Among the promising protein sources are oilseed meals and legumes. Groundnut meal is available in large quantities as a by-product of the oil industry in many countries (Altschul, 1958). Joseph, Narayanarao, Swaminathan & Subrahmanyan (1957) have reported that the incorporation in a poor Indian rice diet of a processed protein food, based on a 3 : I blend of low-fat groundnut flour and chick-pea (Cicer arietinum) flour and fortified with calcium salts and vitamins, caused a significant increase in the retention of nitrogen, calcium and phosphorus by children. The proteins of groundnut contain less lysine, methionine, threonine and tryptophan than milk proteins (Block & Weiss, 1956). No information is available on the comparative retentions of N on a poor Indian rice diet supplemented with equal amounts of proteins from groundnut or milk. Therefore the metabolism of N, Ca and P and the digestibility coefficients and biological value of the proteins and net protein utilization were studied in children receiving a poor rice diet supplemented with the same amounts of proteins, Ca and P either from groundnut flour (GF) or groundnut protein isolate (GPI) fortified with Ca salts and vitamins or from skim-milk powder. T h e results of experiments with these diets relating to 5, Ca and P metabolism have recently been published (Joseph, Tasker, Narayanarao, Sankaran, Swaminathan, Sreenivasan & Subrahmanyan, 1962). The present paper is concerned with the digestibility coefficient and biological value of the proteins and net protein utilization.