Aqueous Enzymatic Extraction of Protein Concentrates from Camelina sativa Oil Cake

Brassicaceae plants can serve as a soy alternative to protein concentrates and isolates. Enzymatic extraction is a promising alternative to degreasing oilseeds as it requires no organic solvents and produces high-quality protein products. The research featured the effect of the enzymatic hydrolysis with cellulolytic and proteolytic enzymes on Camelina sativa (L.) Crantz oil cake. The objective was to reduce the residual oil content and increase the protein yield. Protein concentrates were isolated from seed cake obtained by cold pressing. The method involved sequential hydrolysis with enzyme preparations BrewZyme BGX and Meito renin, followed by alkaline extraction and precipitation at an isoelectric point. The amount of protein in the concentrates was determined by the Kjeldahl method, and the amino acid composition – by capillary electrophoresis. The experiment revealed the optimal concentrations and time, at which the enzymatic hydrolysis effectively removed the residual oil and increased the protein yield. When BrewZyme BGX was applied at a concentration of 8 mg/L for 120 min, it reduced the residual oil content by 5.53%. A further treatment with the proteolytic enzyme Microbial Meito Rennet for 60–120 min increased the protein yield by 10.56–11.33% compared with the fat-free sample. The biological value of protein concentrates obtained by enzymatic hydrolysis was 2% higher than for traditional approaches. The enzymatic extraction made it possible to avoid the de-greasing stage and raise the protein yield up to 68.86% of the total protein content without reducing the biological value of the finished product.