Chemical composition and nutritional evaluation of an underexploited legume, Acacia nilotica (L.) Del.

Nutritional and antinutritional characteristics and biological value of Acacia nilotica (L.) Del. seeds were investigated. The mature seeds contained 234 g kg−1 crude protein, 126 g kg−1 crude fibre, 66.6 g kg−1 crude fat, 39.7 g kg−1 ash and 534 g kg−1 carbohydrates. Potassium, phosphorus, magnesium, iron and manganese occurred in high concentrations. The essential amino acid profile compared well with the FAO/WHO recommended pattern except for cystine, methionine and threonine. Cystine and methionine were the first limiting amino acids. When compared with the globulin fraction, albumins appeared to be a richer source of cystine, methionine, threonine, lysine and tryptophan. Oleic and linoleic acids constituted the predominant fatty acids (66.9%). Both dry-heating and autoclaving reduced the antinutritional components significantly. The in vitro protein digestibilities of raw, dry heat-treated and autoclaved seeds were 61.2%, 77.4% and 80.2%, respectively. Biological value, true digestibility and net protein utilization were significantly higher in processed seed than in raw seeds. The utilizable protein difference was insignificant between raw and processed seed samples.