METHOD FOR OBTAINING SOYBEAN PROTEIN CONCENTRATE FROM SOY MEAL BY MEANS OF EXTRACTION WITH ALCOHOL, OBTAINING A HIGH-PROTEIN FLOUR WITHOUT ANTINUTRITIONAL FACTORS AND A HIGH-QUALITY OIL

摘要

The invention relates to a method for producing a soybean protein concentrate (SPC) flour having a low quantity of soluble carbohydrates and a reduced quantity of oil, comprising the use of ethanol as the only solvent and aqueous solutions of same, which does not require distillation in order to separate the oil, and in which the soybean protein concentrate (SPC) is obtained using a single solvent-removal heat treatment. The method comprises the following steps of: A. preparing the soybeans for treatment involving cleaning, grinding and de-hulling, separating the hull and milling the de-hulled soybeans, thereby obtaining a milled soybean material; B immersing and expanding the soybean material obtained in step A with a solution of ethanol and oil, containing approximately 20 % oil; C. using ethanol to extract oils and phospholipids from the soybean material obtained in step B by reverse-flow percolation of the ethanol and the mixtures (miscellas) of ethanol/oil with decreasing concentrations through the soybean material; D. immersing and expanding the solid soybean material obtained in step C with a mixture of ethanol/oil and carbohydrates, containing up to 5 % carbohydrates; E. using ethanol/water to extract the carbohydrates from the defatted soybean material obtained in step C by reverse-flow percolation of ethanol/water and the mixtures of ethanol/water/carbohydrates with decreasing concentrations through the defatted soybean material; F. separating the soybean oil from the ethanol in the ethanol/oil solution obtained in step C using a non-distillation method; G. conditioning the ethanol obtained in step F for re-use in a closed loop; H. separating the phospholipids and other impurities from the oil obtained in step F; I. separating the carbohydrates from the ethanol/water of the carbohydrates/ethanol/water solution obtained in step E, thereby obtaining molasses and ethanol that is returned to the process; J. separating, concentrating and fermenting the molasses formed by the carbohydrates obtained in step I in order to produce ethanol; K optionally in step J, separating the isoflavones from the molasses prior to fermentation; L. obtaining soybean protein concentrate (SPC) that is free of antinutritional factors and suitable for human and animal consumption, and producing soybean isolates. According to the invention, the only solvent used is pure ethanol and solutions in water and the process is performed without an intermediate solvent-removal step.