Thermal preconditioning to improve canola dehulling

Canola press-cake, a high-protein meal for livestock feed, can be nutritionally enhanced through seed dehulling, which produces a high-protein meal and a hull-rich fraction. Various preconditioning methods have been proposed to improve dehulling efficiency, but their effects on seed structure remain largely unexplored. This study examines the impact of thermal treatments on canola seed and evaluates whether rapid drying techniques can aid hull-embryo separation, improving dehulling performance. Thermal treatment effects were assessed via non-destructive micro-computed tomographic (micro-CT) imaging and a completely randomized dehulling experiment with three replicates. Treatments included rapid seed moistening followed by fluidized bed or microwave drying. Results showed that fluidized bed drying produced a higher yield of seed hulls than other methods. Micro-CT imaging revealed that fluidized bed drying caused embryo shrinkage, facilitating hull detachment, while microwave and oven drying did not induce this effect, explaining their lower dehulling efficiency. We conclude that fast fluidized bed drying effectively preconditions canola seed for mechanical dehulling, improving fraction separation.