Enzyme-assisted aqueous extraction of oil and protein from canola (Brassica napus L.) seeds

The emphasis of this study was to investigate the effect of enzymes on aqueous extraction of canola (Brassica napus L.) seed oil and protein. Four enzymes, Protex 7L, Multifect Pectinase FE, Multifect CX 13L, and Natuzyme, were tested for their effectiveness in releasing oil and protein during aqueous extraction. The enzyme-extracted oil content of canola seeds (22.2-26.0%) was found to be significantly (p < 0.05) higher than that of the control (without enzyme) (16.48%). An appreciable amount of protein (3.5-5.9%) originally present in the seed was extracted into the aqueous and creamy phases during aqueous extraction of oil. The physicochemical properties of oils extracted from canola seed by conventional solvent extraction, and aqueous extraction, with or without enzyme addition were compared. Significant (p < 0.05) differences were observed in free fatty acid content, specific extinctions at 232 and 270 nm, peroxide value, color (1-inch cell) and concentration of tocopherols (alpha, gamma, and delta). However, no significant variation (p < 0.05) was observed in iodine value, refractive index (40 degrees C), density (24 degrees C), saponification value, unsaponifiable matter and fatty acid composition. A better oil quality was obtained with aqueous extraction (With and without enzyme) than with solvent extraction. While the enzymes enhanced the oil extraction. the oil yield was still significantly (p < 0.05) lower than that obtained by solvent (hexane) extraction.