Valorization of some minor plants of Côte d'Ivoire: Biochemical parameters and nutritional composition of the legume Mucuna pruriens seeds according to their maturity stage

Abstract

The present study was aimed at investigating some biochemical properties, mineral contents and amino acid composition in seeds of Mucuna pruriens as a function of ripening stage. These seeds were harvested at different stages of maturation in a field carried out in the center of Côte d'Ivoire (Gbèkê Region). Seeds and pod were separated, and they were oven dried and ground to obtain the crude flour and analyzed according to standard procedures. Results showed that levels of dry matter (85.229-94.025 g.100g-1 dw), lipids (1.503-2.973 g.100g-1 dw), proteins (17.810-28.617 ± 0.296 g.100g-1 dw), fiber (6.483-7.477 g.100g-1 dw), ash (3.922 -9.231 g.100g-1 dw) and total sugars (10.338 -26.210 g.100g-1 dw) , increase significantly with the stage of maturity, while those of carbohydrates (70.282-51.703 g.100g-1 dw) and the energy value (365.893-348.037 Kcal.100g-1) decreases. Mineral analysis revealed that seeds are rich in essential minerals. Potassium (915.54- 20065.73 ug.100g-1) were the most abundant mineral, followed by magnesium (1335.33-16546.66 ug.100g-1), calcium (808.66-7739.39 ug.100g-1) and phosphorus (732.33-7440.00 ug.100g-1). The least abundant minerals were sodium (0.00-60.22 ug.100g-1), zinc (20.25-56.33 ug.100g-1), iron (41.63-475.52 ug.100g-1), copper (9.76-37.99 ug.100g-1) and manganese (0.00-5.94 ug.100g-1). For all assayed minerals, highest levels were founded in the seeds harvested 45 days after fertilization. Amino-acids profile has showed nutritionally useful amounts of essential amino acids such as histidine (18.32-40.81 mg.g-1 protein), isoleucine (30.76-66.35 mg.g-1 protein), leucine (72.47-103.51 mg.g-1 protein), lysine (27.22-57.28 mg.g-1 protein), methionine (25.51-51.74 mg.g-1 protein), threonine (10.91-37.40 mg.g-1 protein), tryptophan (29.22 -61.62 mg.g-1 protein) and valine (35.71-72.74 mg.g-1 protein). The study revealed M. pruriens seeds are rich in energetic and nutritional compounds. However, to optimize their nutritional qualities they may be harvest 35 days after the fertilization of the flowers.