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

Authors: ALHOMODI, AHMAD - South Dakota State University; ZAVADIL, ANDREA - South Dakota State University; Berhow, Mark; GIBBONS, WILLIAM - South 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: 1/24/2022
Publication Date: N/A
Citation: N/A

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: Three-day canola seed sprouting was used as a dehulling mechanism and to provide nutritive meal for food and feed applications. The optimized sprouting and dehulling process resulted in 63.17% sprouts, 29.34% mix fractions (MF) (hulls, ungerminated seed, and delayed sprout), and 8.14% mass loss during germination. 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 reduction of 46.2% in crude fiber, 34.3% reduction in acid detergent fiber, and 43.4% reduction in neutral detergent fiber as compared to defatted raw seed (DFSE). DFSP provided a 10.1% higher protein content and a 5.95% increase in total amino acid content with higher essential amino acids as compared to DFSE. Total carbohydrate was lowered by 5.5%, phytic acid content was lowered by 25.9%, and the ash content was lowered by 5.47% in DFSP, whereas the total glucosinolate content was higher in DFSP (8.8 µM/g) than DFSE (5.5 µM/g). Sprouts and MF showed an oil content of 38.43% and 9.64% as compared to raw seed (34.50%). Sprout oil contained higher amounts of unsaturated fatty acids and free fatty acids, but less saturated fatty acids.