NUTRITIONAL AND ANTINUTRITIONAL COMPOSITION OF ITCHING BEAN (Mucuna pruriens (L.) DC var. pruriens): AN UNDERUTILIZED TRIBAL PULSE IN WESTERN GHATS, TAMIL NADU

Abstract

Five accessions of the underutilized legume itching bean (Mucuna pruriens (L.) DC.) var. pruriens), collected from five different agroclimatic regions in Western Ghats, Tamil Nadu, India were analysed for their proximate and mineral composition, vitamins (niacin and ascorbic acid), fatty acid profiles, amino acid profiles of total seed proteins, in vitro protein digestibility (IVPD) and certain antinutritional factors, to determine their potential as an alternative source to alleviate protein-energy-malnutrition among the people of Tamil Nadu. The crude protein ranged from 27.5 – 31.2%, crude lipid 6.6 – 8.8%, total dietary fibre 6.5 – 9.7%, ash 4.3 – 6.0% and carbohydrates 46.1 – 52.5%. The energy level of the seed (1576 – 1620 kJ100g-1 DM) was comparable with commonly consumed Indian pulses. The investigated seeds were rich in minerals such as Na, K, Ca, Mg and P. The fatty acid profiles  revealed that the seed lipids contained higher concentrations of linoleic acid and palmitic acid. The essential amino acid profile of total seed proteins compared favourably with FAO/WHO (1991) requirement pattern, except that there were deficiencies of sulphur containing amino acids in all the five accessions. The IVPD of the five accessions ranged from 70.1 – 76.5%. The range of antinutritional factors were as follows: total free phenolics, 3.4 – 4.8%, tannins, 0.14 – 0.23%, L-Dopa, 5.4 – 7.0%, phytic acid, 478 – 648 mg100g-1, hydrogen cyanide, 0.24 – 0.38 mg100g-1 and trypsin inhibitor activity, 40.4 – 48.2 TIU mg-1 protein. Verbascose was the principal oligosaccharides in all  accessions. Lower levels of phytohaemagglutinating activity for human erythrocytes of ‘O’ blood group than for ‘A’ and ‘B’ blood groups were found. The antinutritional fatty acid, behenic acid (1.28 – 2.74%) was also detected