LEGUME TOXINS IN RELATION TO PROTEIN DIGESTIBILITY‐A REVIEW

Publisher Website
Google Scholar
Abstract
Proteins capable of inhibiting the proteolytic activity of digestive enzymes are common constituents of legumes. These protease inhibitors are generally believed to be largely responsible for the poor digestibility of the protein of legumes which have been inadequately cooked. This reduction in digestibility is invariably accompanied by an enlargement of the pancreas. Recent studies in the author's laboratory, however, have revealed that only about 40% of the growth‐depressing activity and a similar fraction of the pancreatic hypertrophic effect of unheated soybeans can be attributed to the action of the trypsin inhibors. The poor digestibility and pancreatic hypertrophy that cannot be accounted for by the trypsin inhibitors are most likely the consequence of the refractory nature of the undenatured protein to attack by trypsin. The phytohemagglutinins also play an important role contributing to the poor nutritive value of some legumes, particularly those belonging to the genus Phaseolus. In this case the phytohemagglutinins are believed to exert a nonselective adverse effect on the absorption of nutrients from the intestinal tract rather than a direct effect on the digestive process.