Increasing the Protein Content of Rapeseed Meal by Enzymatic Hydrolysis of Carbohydrates

Enzymatic hydrolysis of rapeseed meal carbohydrates was performed to increase the protein content. Rapeseed meal was first screened and further defatted. Only particles between 0.250 and 0.707 mm in size were used, and the optimum solid/liquid ratio was found to be 10% (w/v). Commercially available carbohydrase enzyme mixtures, Viscozyme ® L, Pectinex ® Ultra SP-L, and Celluclast ® 1.5 L, were used in conditions that minimized protein solubilization from the solid phase. The highest results were achieved with Viscozyme ® L, with a carbohydrate extraction yield of 80% (as determined by reducing sugars content expressed as glucose equivalent units) after 24 h of reaction at 45 oC, pH 3.5, and an enzyme dosage equivalent to 96 fungal beta-glucanase (FBG) added to 5 g of defatted rapeseed meal. The simultaneous use of the different carbohydrases (Viscozyme ® , Pectinex ® , and Celluclast ® ) did not improve the carbohydrate hydrolysis when compared to the use of Viscozyme ® L alone. Viscozyme ® L treatment increased the protein content in the rapeseed meal from 41 to 68%, which allowed the solid to be classified as a protein concentrate.