The preparation of nutritious protein from wool.

I. The nutritive value of solubilized wool protein prepared by dissolving finely ground wool in sodium sulphide-sodium sulphite solution followed by precipitation with 40 % acetic acid has been tested by incorporating it into protein-free diets containing the amounts of vitamins and minerals required by weanling rats. 2. At the level of 10 % (w/w) of the diet, solubilized wool protein failed to support growth in weanling rats, but when the diet was fortified with histidine, methionine and lysine a protein efficiency ratio of up to 1.8 was obtained. The effect of the addition of lysine was marginal. Similar results were obtained with solubilized wool protein prepared from dyed wool suiting material. 3. Apart from the methionine content, which varied from 0.49 to 0.66 g/Ioo g protein, the contents of the essential amino acids in the solubilized wool protein generally met the requirement of the FA0 (1957) provisional pattern, although in many of the preparations the levels of isoleucine and lysine were marginal. The tryptophan content was not determined. Supplementation of the solubilized wool protein with lysine to the level of 6-10 g/Ioo g protein slightly enhanced the nutritive value.