Moisture was determined by gravimetric method, heating in an oven at 105 C until constant mass; total nitrogen was determined according to the Kjeldahl method and converted into protein, using factor 6.25; total lipids were extracted by the Soxhlet technique with hot solvent (hexan) and afterwards were determined by gravimetry; ash was determined by gravimetry of incinerated sample, in muffle, at 550 C.