[Amaranthus cruentus protein concentrate. Extraction methods. Functional properties].

The most favorable conditions of pH, temperature ratio for the yielding of a protein concentrate (PC) of seed flour from Amaranthus cruentus was determined. The optimal values were: extraction pH 11, stirring time 1 h 30 min, precipitation pH 4.5 and a flour/ solvent ratio of 1:15. Obtained the PC, its functional properties were assayed. The PC chemical composition expressed in g/100 g was: protein 50.9: humidity 3.3; ethereal extract 5.8; raw fiber 6.4; ashes 3.8; total carbohydrates 29.9. The following PC functional properties were found: a maximal solubility value of 94.3 at pH 1); emulsification activity (EA) 47.90 +/- 4.9, water absorption capacity (WAC) 2.0 +/- 0.3; and oil absorption capacity (OAC) of 0.7 +/- 0.8. The use of this product as supplement for cereals and for others foods with poor lysine content is considered possible. Despite of the functional properties which show the hydrophilic character of the protein from the Amaranthus cruentus PC, great expectancies are inferred for its future utilization in bread products.