Upcycling Canola Meal as Compared to Soybean Meal by Fungal Bioconversion for Potential Monogastric Animal Nutrition

Abstract

Canola meal (CM) produced after oil extraction has potential to be used as nutrient-rich feeding ingredient for monogastric animals if its ber, anti-nutritional factors can be reduced while essential amino acids can be improved. Fungal bioconversion provided a way of improving feeding value in CM for monogastric animals. This study explored the effects of three fungal strains namely, Rhizopus oryzae ( R. oryzae ), Mucor indicus ( M. indicus ), and Trichoderma reesei ( T. reesei ), via solid state fermentation, on pro les of amino acids, structure carbohydrates, sinapic acid, and in vitro dry matter digestibility (IVDMD) of CM with and without supplement of urea as nitrogen source.Soybean meal (SM) was investigated at the same condition as CM for comparison. Flask trials using each substrate with 70% moisture content were conducted for 192 h at 28°C. T. reesei was determined as the most effective fungal strain due to its higher improvement of total amino acids by 10.7%, and threonine (Thr), methionine (Met), and lysine (Lys) by 19.2%, 20.4%, and 14.4%, respectively, when 1% N urea was supplied. T. reesei also degraded more structural carbohydrates (up to 26.6%) and produced more digestible sugars, compared to other strains. In addition, T. reesei treated SM and CM showed higher IVDMD than non-treated compared with other fungi. This study demonstrated the feasibility of fungal strain in improving feeding value of CM and SM for better monogastric animal diet. Statement Of NoveltyAs the world is facing more unpredictable supply of food, feed and fuel due to economic, political, and climate issues, exploring new resources or valorizing existing resources for these supplies are becoming urgent. As a recent mandate of enhancing biodiesel production in California, United States is effective, planting of more oil seeds especially soybean and canola seeds is required which will generate huge abundance of co-product mainly soybean meal and canola meal. Soybean meal has traditionally been used as main feeding materials due to its high protein and relatively balanced amino acids, while canola meal has lower feeding value due to its relatively imbalanced amino acids and antinutritional factors. Therefore, improving feeding value of canola meal to be more closed to soybean meal will have large bene ts on both canola planters and animal feeding market. This study used several important GRAS fungal strains that have traditionally been used for human food production to process canola meal as compared to soybean meal with solid-state fermentation, to improve the feeding values and digestibility, reducing the impact of biofuel mandate and increasing potential revenues for the rural economy.* Represents signi cant improvement (p < 0.05) as compared to Ctrl.