The Replacement Value of the Alaska Field Pea (Pisum Sativum) for Human Subjects

Abstract

The replacement value of the protein of the Alaska split pea (Pisum sativum) has been compared with that of egg protein. Six young adult women served as subjects. Pea protein was slightly less efficient than egg protein for the human adult subject. The average daily nitrogen balance on the egg diet was -0.10 gm, while that on the pea diet was -0.31 gm. This difference was not statistically significant. The egg replacement value of the pea protein was found to be 95.1%. This indicates that the split pea is a protein food of high biological value for human consumption. When the daily methionine intake was increased to 2.06 gm by supplementation of the pea diet with 1.5 gm of DL-methionine, the egg replacement value for the pea protein was 100% or better for all subjects. If this replacement value is expressed in terms of the positive nitrogen balance obtained in contrast to that on the egg regimen, the average value becomes 110.9%. The average apparent digestibility of egg was 85.6%, of peas 78.8%, and of peas plus methionine 80.0%. Methionine supplements added to the pea diet increased nitrogen retention. The daily nitrogen balances of all subjects were positive during this period, resulting in an average value of + 0.55 gm. This utilization was significantly better at the 1% level when compared with that obtained on either the egg or the pea diet. The average urinary excretion of methionine for each subject was about the same during the egg and pea periods. When the amount of methionine was increased 4 times as a supplement to peas, excretion of this amino acid was approximately doubled.