J R Croat1, B Karki2, M Berhow3, L Iten3, K Muthukumarappan2, W R Gibbons1. 1. Biology & Microbiology Department, South Dakota State University, Brookings, SD, USA. 2. Agricultural & Biosystems Engineering Department, South Dakota State University, Brookings, SD, USA. 3. USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria, IL, USA.
Abstract
AIMS: The objective of this study was to determine the optimal pretreatment and fungal strain to reduce glucosinolates (GLS), fibre and residual sugars while increasing the nutritional value of canola meal. METHODS AND RESULTS: Submerged incubation conditions were used to evaluate four pretreatment methods (extrusion, hot water cook, dilute acid and dilute alkali) and three fungal cultures (Aureobasidium pullulans Y-2311-1, Fusarium venenatum NRRL-26139 and Trichoderma reesei NRRL-3653) in hexane-extracted (HE) and cold-pressed (CP) canola meal. CONCLUSIONS: The combination of extrusion pretreatment followed by incubation with T. reesei resulted in the greatest overall improvement to HE canola meal, increasing protein to 51·5%, while reducing NDF, GLS and residual sugars to 18·6%, 17·2 μmol l-1 g-1 and 5% w/w, respectively. Extrusion pretreatment and incubation with F. venenatum performed the best with CP canola meal, resulting in 54·4% protein while reducing NDF, GLS and residual sugars to 11·6%, 6·7 μmol l-1 g-1 and 3·8% w/w respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The work is significant in that it provides a method of reducing GLS (up to 98%) and neutral detergent fibre (up to 65%) while increasing the protein content (up to 45%) of canola meal. This novel pretreatment and submerged incubation process could be used to produce a canola product with higher nutritional value for livestock consumption.
AIMS: The objective of this study was to determine the optimal pretreatment and fungal strain to reduce glucosinolates (GLS), fibre and residual sugars while increasing the nutritional value of canola meal. METHODS AND RESULTS: Submerged incubation conditions were used to evaluate four pretreatment methods (extrusion, hot water cook, dilute acid and dilute alkali) and three fungal cultures (Aureobasidium pullulans Y-2311-1, Fusarium venenatum NRRL-26139 and Trichoderma reesei NRRL-3653) in hexane-extracted (HE) and cold-pressed (CP) canola meal. CONCLUSIONS: The combination of extrusion pretreatment followed by incubation with T. reesei resulted in the greatest overall improvement to HE canola meal, increasing protein to 51·5%, while reducing NDF, GLS and residual sugars to 18·6%, 17·2 μmol l-1 g-1 and 5% w/w, respectively. Extrusion pretreatment and incubation with F. venenatum performed the best with CP canola meal, resulting in 54·4% protein while reducing NDF, GLS and residual sugars to 11·6%, 6·7 μmol l-1 g-1 and 3·8% w/w respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The work is significant in that it provides a method of reducing GLS (up to 98%) and neutral detergent fibre (up to 65%) while increasing the protein content (up to 45%) of canola meal. This novel pretreatment and submerged incubation process could be used to produce a canola product with higher nutritional value for livestock consumption.