[Relation between the digestibility and protein value of the common bean (Phaseolus vulgaris)]

The main nutritional limitations of common beans are the low digestibility of their protein and the deficiency of the latter in sulfur amino acids. Analysis of the information presented indicates that with 57 samples of different color (23 red, 21 black, 10 white and 3 brown), no relationship was found between protein digestibility and its quality as measured by NPR. Nevertheless, white beans have a higher protein digestibility than black, red and brown. The greater digestibility of white beans, however, does not increase the protein quality when mixed with cereal grains above that observed with black and red, probably because the protein that gives the higher digestibility is highly deficient in its sulfur amino acids content. These aspects require further research for programs aimed at increasing the nutritive value of food grain legumes.