Resumen

URRIBARRI C., A, L; FERRER, O  y  COLINA, A. Extraction and precipitation of the soluble proteins of dwarf elephant grass (Pennisetum purpureum Schum cv. Mott). Rev. Fac. Agron. [online]. 2004, vol.21, n.3, pp.268-279. ISSN 0378-7818.

The main objective of the present study was to set extraction and precipitation conditions for the soluble proteins of the leaves of dwarf elephant grass in order to obtain a protein concentrate suitable as a feed for simple-gutted animals. An alkaline solution was used as extracting agent at two solid liquid ratios (1:10 y 1:15), different pH conditions (between 10 and 12.60), temperatures (between 30 and 90°C) and times (between 5 and 30 min), applied to 5 g (dry weight) of grass. The extracted true protein was determined by Lowry's method. Precipitation conditions were evaluated at pH 4 and 4.5 and temperatures of 50, 65 and 80 °C. Extraction of protein was not affected by time (P>.05), decreased with increasing temperature (P<.05), and increased with increasing pH (P<.05). The greatest yield of extraction, 11.7%, was obtained at pH 12.60, 30°C and a solid liquid ratio of 1:15 for 5 min. The highest precipitation yield, 62.51%, was obtained at 50°C and pH 4. The concentrate had a protein content of 27.93% and the protein turned out to be limiting in phenyl alanine and methionine for swine and poultry.

Palabras clave : dwarf elephant grass; proteins; extraction; precipitation.