Hidrólise enzimática do resíduo da fabricação de pamonha

Abstract

Concern about the environment and the need for a suitable destination for the residues generated in the agroindustrial sector, composed of vegetal biomass, whole plants, straws or agricultural residues, present an alternative to products of fossil origin. In addition, the use of agricultural waste contributes to the sustainability of production and reduces environmental pollution. In this sense, the objective of this work was to characterize the residue of the pamonha manufacturing process and to study the hydrolysis conditions of the material. In order to do so, we used traditional methodologies to characterize the material by determining the moisture content, ash content, grain size of dry material, insoluble and soluble lignin content, holocellulose, hemicellulose and α-cellulose, starch, protein and elemental analysis. After the characterization, a pre-treatment with 0.5% sulfuric acid and a temperature of 120ºC for 15 minutes was carried out, and, finally, hydrolysis processes were studied in order to verify the best condition to obtain the maximum conversion to fermentable. The values obtained from the concentration of lignocellulosic materials and starch in the residue make it a promising source of fermentable sugars. Pre-treatment was efficient, considerably reducing the amount of hemicellulose (from 54.9% to 14.3%), making the cellulose more accessible. To study the hydrolysis of this residue, it was necessary to use enzymatic complexes based on cellulases and amylases. Preliminary tests were conducted looking for the best conditions and variables for hydrolysis studies. The best results were with a pre-treated sample using 20 FPU/g biomass Accellerase®, 0.16 μL/mL Liquozyme® Supra 2.2 and 2.50 μL/mL AMG®, and the use simultaneous of these complexes in the saccharification step with hydrolysis time of 72 h. Thus, it was possible to perform a central compound design (CCD) to maximize the hydrolysis conditions of the studied material, with 22% of biomass, pH of 5.45, temperature of 60°C and time of 72 h, presenting a conversion in glucose of 94.51% ± 1.6, a value close to that obtained by the empirical model, which described well the process of hydrolysis of the residue of the pamonha.