The Antioxidant Properties of Bioactive Peptides Derived from Enzymatic Hydrolyzed or Fermented Canola Meal and Its Effects on Broiler Chickens

The present research was designed to investigate the effect of enzymatic or fermentative hydrolysis of canola meal (CM) protein as a strategy to improve its nutritional value. In the in vitro phase of this research, the antioxidant properties of bioactive peptides derived from enzymatic hydrolyzed and solid-state fermented (SSF) CM were studied and then the performance, caecum bacteria and the morphology of the small intestine and liver of broiler chickens fed the processed CMs were determined. The antioxidant activity of the extracts was compared with DPPH and ABTS radical inhibition tests. Enzymatic hydrolysis was performed using commercial protease and fermentation was carried out by the SSF method. HPLC method was used for chemical analysis. In the farm experiment, 490 one-day-old Ross 308 chicks were used in a completely randomized design with 7 treatments, 5 replications, and 14 birds each. The experimental diets were the CM free diet as control (T1) and the diets containing 15% CM (T2), 15% CM supplemented with a commercial protease enzyme (T3), 15% CM previously hydrolyzed using commercial protease enzyme (T4) and the diets containing 15% CM fermented by Lactobacillus reuteri (T5), Lactobacillus fermentum (T6) or Bacillus subtilis (T7). The CM hydrolyzed using commercial protease enzyme seems to have the best antioxidant activity. The consumption of 15% CM in the diet reduced the performance of broiler chickens compared to the control group (P < 0.05), but the villi length as an index of intestinal morphology was improved in all segments of the small intestine compared to the control group (P < 0.05). Also, no significant difference was observed between different treatments for the population of Lactobacillus and Escherichia coli bacteria.