In vitro digestibility of globulins from cowpea (Vigna unguiculata) and xerophitic algaroba (Prosopis juliflora) seeds by mammalian digestive proteinases: a comparative study

Globulins were purified from mature and immature cowpea and algaroba seeds by gel filtration (S-200), anion exchange (DEAE-Sepharose) and other chromatographic methods. These globulins (native and heated) were submitted to hydrolysis by pepsin, chymotrypsin and trypsin and their digestion products were analysed by SDS-PAGE. Results showed that native globulins of both legumes were weakly digested by pepsin and were not digested by serine proteases. Heated proteins from cowpea were digested more rapidly by pepsin and chymotrypsin than was algaroba globulin. Trypsin rapidly digested proteins from both cowpea and algaroba. Comparing the hydrolysis of bean globulins to the algaroba globulins by mammalian enzymes, the globulins from immature cowpea showed better digestibility than mature cowpea; globulins from algaroba pod, which is used as an alternative food, were difficult to digest.