Nutritional Evaluation of Low Temperature Alkaline Extracts From Beef Bones

Protein coagula precipitated from aqueous extracts of beef boning room wastes at pH 7.0, 6.0 and 5.1, were analyzed for amino acid composition including hydroxyproline. Nutritional parameters calculated from the amino acid composition were % essential amino acids (% EAA), essential ammo acid index (EAAI) and PER. The typical % EAA and PER values for the coagula (41.3 and 3.1, resp.) were comparable to beef. The EAAI was lower (67.5) due to the low tryptophan content. The parameters were not affected by the different pH of precipitation. Low fat and hydroxyproline contents of the extracts as compared to the raw material confirmed the effectiveness of the alkaline extraction procedure in preferentially extracting the lean beef protein.