Composition of canola seed sprouts fermented by Aureobasidium pullulans, Neurospora crassa, and Trichoderma reesei under submerged-state fermentation

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: Food and Bioproducts Processing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2021
Publication Date: 1/23/2021
Citation: Alhomodi, A.F., Zavadil, A., Berhow, M.A., Gibbons, W.R., Karki, B. 2021. Composition of canola seed sprouts fermented by Aureobasidium pullulans, Neurospora crassa, and Trichoderma reesei under submerged-state fermentation. Food and Bioproducts Processing. 126:256–264. https://doi.org/10.1016/j.fbp.2021.01.008.
DOI: https://doi.org/10.1016/j.fbp.2021.01.008

Interpretive Summary: Seed sprouts are nutrient-rich components; and their use in human and animal diets have increased in recent times. Microbial fermentation of seed sprouts not only improves the nutrient digestibility but also elevates the nutritional characteristics by lowering the level of antinutritional factors. This study deals with the evaluation of effect of sprouting followed by subsequent fungal fermentation on the nutritional characteristics of canola seed sprouts. Canola seeds were soaked overnight and sprouted over a 6-day period under room temperature and room lighting. Dried and ground seed sprouts were further subjected to submerged fungal fermentation using three different fungal strains. Fermented seed sprouts had improved nutritional characteristics including high level of proteins and low level of antinutritional factors when compared to untreated seeds. But there was significant reduction in the oil content of canola seeds. Results indicated that sprouting hydrolyzed proteins into peptides, which are more soluble, hence the high protein titers detected in the liquid fraction. Results also suggested that sprouting prior to fermentation could help in reducing the overall fermentation duration. These results suggested that sprouting prior to fermentation could potentially lead to the production of nutritionally enriched canola based high protein ingredient. Further research needs to be conducted to determine if nutritional characteristics of sprouts will change during oil extraction process.

Technical Abstract: Seed sprouts are nutrient-rich components; and their use in human and animal diets have increased in recent times. Microbial fermentation of seed sprouts not only improves the nutrient digestibility but also elevates the nutritional characteristics by lowering the level of antinutritional factors (ANFs). This study deals with the evaluation of effect of sprouting followed by subsequent fungal fermentation on the nutritional characteristics of canola seed sprouts. Canola seeds were soaked overnight and sprouted over a 6-day period under room temperature and room lighting. Dried and ground seed sprouts were further subjected to submerged fungal fermentation using three different fungal strains (Aureobasidium pullulans, Trichoderma reesei, Neurospora crassa). Fermentation was continued for 5-day period with daily sampling to analyze crude protein content and ANFs amount present in the fermented sprouts. Seed sprouts had improved nutritional characteristics including high level of proteins and low level of ANFs when compared to seeds. But there was significant reduction in the oil content of canola seeds. Fermentation with T. reesei further improved the protein content of sprouts while N. crassa fermented sprouts exhibited slight reduction in crude fiber content. Results indicated that sprouting hydrolyzed proteins into peptides, which are more soluble, hence the high protein titers detected in the liquid fraction. Results also suggested that sprouting prior to fermentation could help in reducing the overall fermentation duration. These results suggested that sprouting prior to fermentation could potentially lead to the production of nutritionally enriched canola based high protein ingredient. Further research needs to be conducted to determine if nutritional characteristics of sprouts will change during oil extraction process.