Protein Nutritive Value of Legume - Cereal Blends

Abstract

The protein nutritive values of six legumes were evaluated in equal blends with wheat flour and milled rice by feeding to weanling male rats. Field pea blends were essentially equal to soybean blends in weight gain, true protein digestibility (TPD), protein efficiency ratio (PER) and true biological value (TBV) but showed slightly lower feed intakes. Field bean and lentil blends appeared variable in feed intake, weight gain and TPD, and were significantly lower than field peas in TPD and PER. Broad bean and fababean were inferior sources of protein for the growing rat, even though blended with wheat or rice. While milled rice was substantially lower in protein content, the rice protein contained more lysine and threonine than wheat flour. When fed on an equal protein basis, the weanling rats showed better growth and protein utilization on the legume-rice diets than with legume-wheat blends. Lysine was the first limiting amino acid in the wheat-based diets, while the most deficient amino acid varied with legume species in the legume-rice blends. Chemical score gave a good prediction of protein nutritive value and would be a useful test for protein quality in legume breeding programs.