Nutrient and Chemical Evaluation of Raw Seeds of Five Varieties of Lablab purpureus (L.) Sweet

The proximate and mineral compositions, vitamins (niacin and ascorbic acid), seed protein fractions, amino acid profiles, fatty acids, in vitro protein digestibility and anti-nutritional factors of five varieties of Lablab purpureus were analysed. The major findings of the study were as follows; crude protein ranged from 20.46-25.47%, crude lipid 2.69-4.17%, total dietary -1 fibre 4.98-6.90%, ash 3.97-4.48% and carbohydrates 60.63-66.32%. The energy level of the seed (1524.20-1604.34kJ100 DM) was comparable with commonly consumed Indian pulses. The seeds were found to be rich source of minerals, such as sodium, potassium, calcium, magnesium, phosphorus and iron. The data on seed protein fractions revealed that the globulins constitute the major bulk of the seed protein as in most legumes. Profiles of amino acids of total seed proteins detected in the present study revealed that they contain relatively higher levels of all essential amino acids except tryptophan and sulphur containing amino acids compared with the FAO/WHO (1991) requirement pattern. The seed lipids contained a large proportion of unsaturated fatty acids. The in vitro protein digestibility of the legumes under study ranged from 64.36-1 -1 70.30%. The antinutritional factors ranged from; total free phenolics, 0.21-0.32g100g, tannin, 0.23-0.40 g100g L-DOPA, , -1 -1 0.21-0.49 g100g1, phytic acid, 314-421mg 100g , hydrogen cyanide 0.22-0.33mg 100g , trypsin inhibitor activity, 24.30-1 34.56 TIU mg protein. Stachyose was the principle oligosaccharide of all the varieties of Lablab purpureus. Lower levels of phytohaem-agglutinating activity for human erythrocytes of 'O' blood group than 'A' and 'B' blood groups were found in all the varieties.