Obtenção de concentrado proteico de soja a partir da extração hidroalcoólica

Abstract

The valorization of agribusiness by-products is one of the most promising strategies for enhancing the efficiency and profitability of the production chain. This study aimed to obtain Soy Protein Concentrate (SPC) with a protein content above 60% through a hydroalcoholic extraction process using HiPro soybean meal, a by-product of the oil extraction industry. Several variables were evaluated, including temperature, ethanol:water solvent ratio, type of soybean meal (wet or dry), and solvent addition method. Two extraction approaches were employed: batch and continuous. In the batch method, conducted at 60 °C with wet meal, the solvent ratios tested were 1:0, 1:1, 3:1, and 1:3 (ethanol:water). This method showed low efficiency due to its limitations, particularly the rapid saturation of the meal by the solvent. In contrast, the continuous method employed a packed extraction column to simulate an industrial countercurrent extraction process, allowing solvent percolation through the meal. Temperatures of 50 °C, 60 °C, and 70 °C were tested, as well as different meal types and solvent addition methods, with solvent ratios of 1:1 and 2:3. The batch method did not yield significant results, while the continuous process achieved SPC with protein content close to 65%. The best condition was observed at 70 °C, with a single solvent addition using a 1:1 ethanol:water ratio. In all experiments, the meal:solvent ratio was maintained at 1:6. In addition to SPC, a micellar phase was also obtained and concentrated into soybean molasses, a by-product with high commercial potential for use in animal feed or ethanol production, contributing to the sustainability of the process. Protein quantification was performed using the Kjeldahl method, ensuring reliable and comparable results. This study demonstrated the technical and scientific feasibility of the process, aligning sustainability, efficiency, and by-product valorization.