University of Saskatchewan, Canada
Miss Shuyu Shang graduated from University of Saskatchewan in 2016 from the department of Food and Bioproduct Sciences. She joined the College of Pharmacy and Nutrition, at the University of Saskatchewan for her MSc program in September 2016. During her Master degree program, her efforts have included studies of gum extraction and utilization in beverages.
Statement of the Problem: Oilseeds grown in Canada, including flaxseed, canola, camelina, radish and Brassica carinata have common structural features that include a hull with low protein and oil content and an inner kernel that has much higher concentrations of these nutrients. Milling oilseed typically leads to a coarse meal that can be classified using air to separate the hulls and meal based on differential aerodynamic properties. The purpose of this study is to determine the influence of different seed dehulling methods on oil content and elemental composition of hull- rich and kernel- rich fractions and optimize wet dehulling methods. Methodology & Theoretical Orientation: Seeds were milled using either disc or roller mill devices after equilibrating at –38 ºC or 22 ºC. Milled seed was suspended in one of three non-toxic solvents with densities greater than water; triacetin, polyethylene glycol (PEG) 300, and glycerol. In all samples sedimentation and floatation were observed. In addition, ethanol or distilled water were also added to the solvents to lower viscosity and density. After settling floating and settled fractions were separated and rinsed for further analysis. Oil, carbon, hydrogen, nitrogen and moisture content of all fractions were analyzed. Findings: Pre chilling of the seed improved milling efficiency, and disc milling gave a higher recovery rate than roller milling. The carbon, nitrogen, oil and sterol contents of kernel enriched floating fractions were higher than for the hull rich settling fractions. The triacetin and PEG produced superior separations when compared to samples separated with glycerol. Conclusion & Significance: All milled oilseeds were successfully separated using the solvent systems tested. Most solvent systems produced excellent separation. From the comparison of oil content in the hull and kernel fractions, triacetin or triacetin-EtOH solutions were more effective for the density separation of oilseed meal from hull.