Nutritional evaluation of germinated seeds of coastal sand dune wild legume Canavalia cathartica

Uncooked and cooked germinated seeds of the wild legume, Canavalia cathartica grown on the southwest coastal sand dunes of India were evaluated for proximate composition, minerals, amino acids, in vitro protein digestibility, fatty acid methyl esters and antinutritional features. The crude protein (24–23.2%; P = 0.009), true protein (19.8–8.4%; P = 7.86 × 10^-05) and crude fiber (1.2–1.1%; P = 0.02) of germinated seeds were significantly decreased on cooking, while the crude lipid (2.7–2%; P = 0.004), nitrogen free extractives (69.3–70.3%; P = 0.01) and calorific value (1627–1663 kJ 100 g^-1; P = 0.0009) raised significantly. Albumin fraction was significantly higher among the protein fractions (uncooked, 11.8%; cooked, 4.9%; P = 7.86 × 10-05), while the rest significantly lowered on cooking (P 0.01) except for glutelin (0.92–1.4%; P = 0.31). The SDS-PAGE of albumin and globulin fractions revealed a substantial reduction in the intensity of bands in cooked seeds. Although most of the minerals severely drained in cooked seeds, magnesium, iron, copper and manganese fulfilled the NRC/NAS standards. Many essential amino acids (threonine, valine, isoleucine, leucine, phenylalanine + tyrosine, lysine and histidine) of uncooked and cooked seeds surpassed the FAO/WHO pattern. The histidine of germinated seeds was higher than whole egg protein (2.7–3.5 vs. 2.4%). The in vitro protein digestibility of germinated seeds elevated significantly on cooking (59.6–71.7%; P = 0.02). Cooking also increased unsaturated fatty acids, particularly the linoleic acid (0.35–3.95 g 100 g^-1 lipid) and also P/S ratio (0.11–0.78). The germinated seeds were devoid of tannins and trypsin inhibitors, whereas the total phenolics and hemagglutinin activities considerably decreased on cooking. The overall nutritional qualities of germinated seeds of coastal sand dune C. cathartica is superior to dry seeds, but demands additional suitable method to eliminate the toxins or to decrease below threshold level.