Meal nutritional characteristics and oil profile of sprouted, dehulled, and solvent-extracted canola

Authors: ALHOMODI, AHMAD - South Dakota State University; Berhow, Mark; GIBBONS, WILLIAM - South Dakota State University; MONONO, EWUMBUA - North Dakota State University; KARKI, BISHNU - South Dakota State University

Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2022
Publication Date: 2/4/2022
Citation: Alhomodi, A.F., Berhow, M.A., Gibbons, W.R., Monono, E., Karki, B. 2022. Meal nutritional characteristics and oil profile of sprouted, dehulled, and solvent-extracted canola. Journal of the Science of Food and Agriculture. 102:4410-4418. https://doi.org/10.1002/jsfa.11794.
DOI: https://doi.org/10.1002/jsfa.11794

Interpretive Summary: This study showed that an optimized 3-day canola sprouting procedure will enable the separation of hulls from the sprouts with an enhanced nutritional composition of the resulting meal. Canola is a major oilseed crop, and the seed meal that remains after hull removal and oil extraction has an ideal protein content and composition for animal feed applications. Hulls contain indigestible fiber that could be used in other applications but are difficult to remove in intact seeds. Sprouting makes hull removal more efficient and will also lower other anti-nutritional factors such as phytic acid and high fiber that limit their use in animal feed, while not significantly affecting the oil and protein content. Sprouting enabled the more efficient removal of hulls and reduced the oil content slightly, and decreased the crude fiber and phytic acid content, while increasing slightly the protein and glucosinolates in the canola seeds. Hulls do not contribute to the nutritional value of canola seeds in animal feeds, but could be used for other fiber applications. Hulls are difficult to remove in intact seeds. Three-day sprouting makes hull removal much more efficient and the resulting sprouted meal animal feed nutritional value is slightly enhanced. This will allow for better utilization of canola seed meals for oil extraction and animal feed uses as well as providing another fiber fraction with the separated hulls.

Technical Abstract: BACKGROUND Canola meal has limited utilization in feed and food applications because of the presence of antinutritional factors and a high fiber content. Thus, the present study used 3-day canola seed sprouting followed by hull removal to improve the nutritional quality of canola as a feed and food ingredient to further enhance and diversify the canola market. RESULTS Seed sprouting and the hull removal process resulted in 63.2% sprouts, 29.3% mix fractions (MF) (hulls, ungerminated seed, and delayed sprouts) and 8.1% mass loss during sprouting. Fresh sprouts and MF were dried, ground and defatted to compare the obtained meals and oils with their counterparts of raw seed. Defatted sprouts (DFSP) resulted in a 46.2% reduction in crude fiber, a 34.3% reduction in acid detergent fiber and a 43.4% reduction in neutral detergent fiber compared to defatted raw seed (DFSE). DFSP provided a 10.1% higher protein content and a 5.9% increase in total amino acid content with higher essential amino acids compared to DFSE. Total carbohydrate was lowered by 5.5%, phytic acid content was lowered by 25.9%, and ash content was lowered by 5.5% in DFSP, whereas total glucosinolate content was higher in DFSP (13.1 µmol'g-1) than in DFSE (8.8 µmol'g-1). Sprouts and MF showed an oil content of 38.4% and 9.6%, respectively, compared to raw seed (34.5%). CONCLUSION Sprouting and hull removal of canola seed can potentially provide nutritive meal for food and feed applications.