X-ray analysis of heat and mechanical processing effects on canola seed structure

Canola, a crop of significant functional value, is processed by pressing to produce co-products such as oil, and meal that are valued as food and feed ingredients. The efficiency of canola seed pressing is improved by heat treatments and mechanical deformation, often using rollers and expellers to help rupture the cell walls and increase the quantity of oil recovered. In conventional processing, the seed hull remains associated with the seed throughout processing. The seed hull has low protein, low oil, and high fiber. The presence of hull in canola meal decreases the value of the meal and opportunities for increasing meal quality. Removing canola hull before extracting the oil produces a meal with greater protein content (50% increase) and lowers fiber content (10% decrease). Currently, there is insufficient information about the detailed seed anatomy of canola, and how processing methods affect the seed structure.

The purpose of this study is to investigate the impact of heat treatment and mechanical processing to improve seed hull removal and preserve or enhance the nutritional value of meal. Heat treatment prior to dehulling might alter seed nutritional components, and mechanical processing during dehulling might alter inner kernel structures resulting in transfer of kernel oil to the hull. This transfer is undesirable as extra processing would be required to recover oil from both the kernel and the hull after separation.

The 3D image data collected enables the observation and quantification of various aspects of seed anatomy, such as seed coat thickness, inner kernel structure, and oil body sizes. By following the effects of seed pre-treatments on anatomy prior to dehulling it is possible to look for improved approaches for dehulling. An efficient dehulling process could contributes to production of oil and meal with improved quality.