Effect of composition and processing on the nutritive value of some leguminous seeds

Abstract Leguminous seeds are potential protein sources with variable nutritive value because of their amino acid pattern. Their nutritive value may be affected by some nonprotein components: tannins, poorly digestible carbohydrates and antinutritional factors. Some deleterious effects may be avoided by different technological processes developed to eliminate or inactivate the indesirable compounds. Unfortunately, the processes may themselves result in a decrease of the nutritive value of the proteins by making their amino acids unavailable to the animal organism. We studied some of these effects in field beans, soybeans, lupines and peas, using digestibility and growth trials with rats. The samples were used as sole proteins in balanced diets and supplemented with synthetic amino acids to meet the requirements. The significance of differences in apparent digestibilities was estimated from the amino acid composition on the feces using two calculation procedures described previously. These techniques were developed to assess the relative part of the undigestible food and of the intestinal bacteria in the feces. The growth of the animals was compared to a control group eating a fish meal diet. The free amino acids in blood and muscle were estimated in order to emphasize some amino acid unavailability.