[Several methodologic approaches to determining the biological value of proteins].

By summarizing the results of their personal experimental research work and literature sources the authors come to the conclusion that a temporal determination of the free amino acids concentration in the portal vein blood of rats enables one to judge about the summary duration of the first two stages of the protein assimilation, namely about the rate of the protein digestion and that of the amino acids absorption. The aminogram of free amino acids in the blood of the portal vein shows a marked tendency toward convergence with the consumed protein aminogram.