Enriquecimento protéico do facheiro por fermentação semi-sólida.

Abstract

The conditions of the semi-arid region of northeastern Brazil have led farmers to use the facheiro (Pilosocereus pachycladus) as alternative food for their flocks, since its use is possible throughout the year, especially in the occurrence of prolonged droughts. The branches of the plant are cut and burned to eliminate the spikes before they are chopped or crushed to be offered to the animals. However, after burning facheiro has low protein content and dry matter when compared to other fodder used, which brings adverse consequences to the herd when it makes exclusive use of this forage. The objective of this work was the study of protein enrichment facheiro by use of the yeast Saccharomyces cerevisiae, evaluating the initial concentration of yeast and the thickness of the substrate layer on the protein content, applying the full factorial design experiments 22 + 2 the center point and the response surface methodology. Branches of facheiro were processed, resulting in mucilage with pasty consistency. The enrichment of this protein mucilage was performed employing the solid state fermentation in a batch system, under static conditions, and making the addition of different concentrations of yeast as factorial design with crude protein determinations at different time intervals. The substrate was placed in a cylindrical plastic bioreactor, with a volume of 2.5 liters, were placed in an oven with forced air circulation at 35 0C. Yeast different initial concentrations (1, 3 and 5%) and substrate thicknesses of 3, 6.5 and 10 cm were measured. Before and during protein enrichment facheiro analyzes of moisture, pH, acidity and crude protein performed. An evaluation was made of the variables studied, and it was observed that with 95% confidence, and an R2 of 0.974, the largest protein content was obtained with the addition of 5% yeast and thickness of the substrate of 10 cm. Accordingly the protein increase was about 163%, based on the protein content of the facheiro prior to addition of yeast. Of the two variables, only the concentration of yeast in the fermentation process showed influence of facheiro.