CHEMICAL COMPOSITION OF DRY SEEDS AND FRESH LEAVES OF WINGED BEAN VARIETIES GROWN IN THE U.S. AND PUERTO RICO

Abstract

ABSTRACT Nutrient composition of undehulled, dehulled dry seeds, seed hulls, and fresh leaves of different varieties of winged bean ( Psophocarpus tetragonolobus ) has been determined. The seeds contain high levels of protein ranging from 31.56–41.35% in the undehulled and 35.66–50.92% in the dehulled. Seed hulls have a range of 8.3813.49% protein. Ether extracts in the seeds range from 16.24–19.71% in the undehulled and 18.12–25.25% in the dehulled seeds. Cell solubles are in the range 89.70–93.64% and lignin content is considerably low. The leaves are high in protein ranging from 27.94–35.07%, ether extract 7.24–9.0%, neutral detergent fiber 37.80–43.72%, acid detergent fiber 19.07–20.82, ash 6.89–8.75%, and lignin 5.47–8.84%. The dry dehulled and undehulled seeds contain high calcium 0.28–0.86%, phosphorous 0.36–0.72%, and iron 58–308 ppm. Most of the iron was concentrated in the seed hulls which showed values as high as 513 ppm. Calcium content in the leaves, 3.21–4.41%, was much higher than in the seeds. The leaves are considerably higher in iron, phosphorous, potassium, and manganese. High lysine, tryptophan, aspartic acid, glutamic acid, and leucine levels were obtained in the seeds, seed hulls, and leaves. The limiting amino acids appear to be the sulfur amino acids. The protein scores for the seeds range from 65.5–86.8%.