Chemical methods of evaluating protein quality

Abstract

The nutritive value of proteins 91All measures of protein quality are a function of the limiting amino-acid, because the usefulness of a protein is limited by the amino-acid in shortest supply. The tests do not, therefore, yield any information about the other amino-acids, i.e. the potential value of the protein if given in combination with other proteins. This point needs emphasis because so often its B.V. or P.E.R. is taken as a complete description of a protein. It is possible to find two proteins with the same B.V. but with different amounts of the non-limiting essential amino-acids.

Section D. Nutritive value of milk and milk products

“…Indeed, with increasing attention being paid to the essential fatty acids in the diet and their protective role, it is possible that milk fat, along with certain other fats, may be found to play an important part in providing protection against atherosclerotic conditions. This suggestion is advanced by Halden (2) in a review of recent work and is also in line with the conclusions of other workers (3,4,5). The main weight of scientific evidence would now seem to be against any drastic change in human dietaries at the present time.…”

Leaf Proteins as Foodstuffs, Nutritive Value of Leaf Protein Concentrate, an In Vitro Degestion Study

“…On the basis of amino acid composition, LPC from a wide variety of plant species may have high nutritive value (76). However, amino acid composition alone may not give a true picture, since processing may have a deleterious effect on the nutritive value of some proteins (6,17). Carpenter (6) The nutritive value of leaf protein concentrate was estimated with an in vitro enzymatic digestion and compared with 12 common food proteins.…”

“…However, amino acid composition alone may not give a true picture, since processing may have a deleterious effect on the nutritive value of some proteins (6,17). Carpenter (6) The nutritive value of leaf protein concentrate was estimated with an in vitro enzymatic digestion and compared with 12 common food proteins. Digestibility was estimated from the total amount of amino acids released by pepsin followed by pancreatin hydrolysis.…”

Pea Protein Evaluation, Correlation between Alcohol-Insoluble Substances and Lysine Availability in Canned Peas

“…That the DNFB procedure indicates the availability of lysine was shown by Carpenter (6), who found a clear correlation between the gross protein value for chicks and available lysine in fish and milk products as well as in leaf, cereal, and oilseed products. Mauron (15) reported that lysine may be made nutritionally unavailable in dried milk, and the extent of this damage can be measured by determining available lysine by the DNFB procedure.…”