• The financial support of the Fats and Proteins Research Foundation for the pursuit of this work is gratefully acknowledged.


SUMMARY— Studies were undertaken to develop a nutritious and aesthetically attractive protein concentrate from commercial meat and bone meal. Flotation in carbon tetrachloride was used to separate meat residues from the bulk of the bone. The meat residues had moderate nutritional merit in rat feeding trials. Further improvement was achieved by size separation or by base extraction. The finer fraction from size separation had a more favorable amino acid balance and gave better growth rates and protein efficiency ratios (PER) than did the unfractionated material. Growth rates increased markedly as the amount in the diet was increased to give 15 and 20% protein. It had more than an additive effect on growth and PER as a supplement to wheat flour or whole corn. Extraction with base improved amino acid balance, growth response and flavor. Addition of 9% of the base-extracted material to rice or biscuits had little effect on flavor; a gray-red color remained prominant. Overall yields of the base-extracted material starting with meat and bone meal were about 34%. The protein content of the product was about 88% on a dry weight basis. Its PER when 2% methionine was added was 75% of that of casein (without added methionine) in a rat feeding experiment. The cost of production is estimated at about $0.13/lb when allowance is made for methionine addition and for sale of residues from the production process as an animal feed supplement