Análise de diferentes volumes de destilados na análise de proteína bruta pelo método de kjeldahl

Abstract

The study aimed to identify and analyze different volumes of distillate from the distillation stage, in the analysis of crude protein (CP) in order to obtain a reduction in time, as well as a reduction in the cost of analysis. In addition to reducing waste of chemical reagents. The experiment was carried out at the Laboratory of Animal Nutrition (LABNUTRI) located at the Campus of Engineering and Agricultural Sciences (CECA) using the Kjeldahl method to determine the value of organic nitrogen, thus verifying CP. The analyzed foods were: soy bran, corn bran, sorghum bran, in natura sweet potato and brewery residue. The experiment was divided into four treatments with increasing distillate volumes: 45, 55, 65, and 75 mL with five repartitions each. The 75ml volume of the distillate was the reference volume in relation to the other volumes. No significant difference was observed for the first two distillate levels when the soy protein analysis was analyzed, showing the parity and consistency of the standardization between these two volumes. However, a significant difference was observed when comparing these average values of the treatments with 45 and 55 mL of the distillate in relation to the volumes of 65 and 75 mL. It is concluded that in foods with a high CP content, such as soybean meal, the recommendation is to increase the volume, however, to adjust the volume, further research is needed, maintaining the integrity of the analysis. Because more chemicals are needed. However, for foods with a lower CP content, the distillate may decrease in volume to 45mL.

Keywords: chemical analysis, animal nutrition, nitrogen.