The direct use of leaf protein in human nutrition

It is suggested that, under certain circumstances, the conversion of part of the protein in leaves into human food could be more efficiently effected by industrial chemical methods and equipment, than through the ruminant. During the preparation of this protein other useful materials could be made from the leaves. A description of the various methods that have been evolved for the separation of leaf protein is given. Although adequate feeding experiments with leaf proteins have not yet been made, the available data on amino-acid composition and early feeding experiments (Nevens, J. Dairy Sci., 1921, 4, 552) with dried leaves suggest that such protein is of high biological value. Grass, lucerne and cabbage are considered the best sources. On the average the yield of soluble protein is 30 per cent. and the unextracted protein remains in the fibre and is still available as a feedingstuff for ruminants. It is estimated that 200 lb. of leaf protein N could be harvested from an acre each year, and suggested that research should now consider the maintenance of a supply of leaf material of high N content during several months of the year, and the design of a suitable macerating plant. [D. P. Cuthbertson]