DETERMINATION OF CHEMICAL COMPOSITIONS AND GLYCEMIC INDICES OF LABLAB PURPUREUS AND PHASEOLUS LUNATUSSEEDS

Abstract

The chemical composition and glycemic indices of Lablab purpureus and Phaseolus lunatus seeds were determined using standard methods. The proximate composition (%) of Lablab purpureus and Phaseolus lunatus seeds were Moisture Content (6.26 and 7.40), Ash (4.09 and 4.25), Fat (6.13 and 9.51), Fibre (10.29 and 5.77), Protein (22.24 and 20.23) and Carbohydrate (51.00 and 52.65) for Lablab purpureus and Phaseolus lunatus seeds respectively. Mineral composition (mg/100g) were P (230.15 and 380.83), Zn (2.73 and 4.26), Fe (8.84 and 7.74), Mg (11.87 and 11.49), Cu (0.78 and 1.53), Cd (0.05 and 0.05), Ca (791.25 and 300), Na (30.69 and 27.31), and K (27 and 38.5); Ca/P (3.44 and 0.79), Na/K (1.14 and 0.71), Zn/Cu (3.5 and 2.75) for Lablab purpureus and Phaseolus lunatus seedsrespectively. However, Co and Pb were not detected in both samples. Phytochemical screening showed the presence of saponin, flavonoids, alkaloids and tannins in both samples. The antioxidant properties were ferric-reducing property (12.75 mg/g and 20.54 mg/g), vitamin C (8.75 mg/g and 35.01 mg/g), total phenol (2.05 mg/g and 2.02 mg/g), free radical scavenging property (60.16% and 46.52%) and flavonoid (3.22% and 3.47%) for Lablab purpureus and Phaseolus lunatus seeds respectively. The Antinutritional compositions were phytate (6.51% and 2.64%), saponin (4.66% and 5.15%), oxalate (3.20 mg/g and 5.19 mg/g), tannin (1.07 mg/g and 1.22 mg/g) and alkaloid (1.40% and 1.29%) for Lablab purpureus and Phaseolus lunatus seeds respectively. The amino acid profile were Total Amino Acid (83.56 and 94.40), Total Essential Amino Acids (42.76 and 48.51), Total Non-Essential Amino Acids (40.8 and 45.89) and Total Sulphur Amino Acids (1.73 and 2.49) for Lablab purpureus and Phaseolus lunatus seeds respectively. Lablab purpureus and Phaseolus lunatus seeds have Glycemic Index of 50.86% and 58.21% respectively. Lablab purpureus has low Glycemic Index and Phaseolus lunatus seeds has medium Glycemic Index. The findings revealed that both seeds possessed good nutritional quality required in human diet together with adequate antioxidant properties that could help in fighting various cardiovascular diseases. The low and medium glycemic indices of Lablab purpureus and Phaseolus lunatus seeds respectively prove them to be good source of food required by diabetic patients