Availability of sulphur amino acids in protein foods

Abstract

In the first paper of this series Similarly Morrison & Sabry (1963) have noted some samples of fish flours in which the nutritive values, measured under conditions of methionine deficiency, were not related to the methionine content. Again, Ford (1962) has shown that in a series of whale-meat meals of widely differing protein quality there was little difference in the levels of several essential amino acids including methionine. Using the proteolytic organism Streptococcus zymogenes, Ford (1962) obtained 'available ' methionine values for thirty-nine samples of animal protein concentrates which in all but six instances were less than two-thirds of the corresponding total values, and these lower 'available' values showed a closer correlation with rat NPU values.