The bioavailability, small size and direct absorption in the blood, make nanoparticles (NPs) a remarkable feed additive in the aquaculture industry. Therefore, dietary iron oxide nanoparticles (Fe2 O3 -NPs) were used to examine their effects on growth, nutrient absorption, body composition and blood indices in Cyprinus carpio (Common carp) fingerlings. Healthy C. carpio fingerlings (n = 270) were fed with six canola meal based experimental diets (D1-control, D2, D3, D4, D5, D6) supplemented with 0, 10, 20, 30, 40 and 50 mg/kg Fe2 O3 -NPs respectively. A total of 15 fingerlings (average initial weight 5.51 ± 0.04 g/fish) were kept in triplicates for 70 days. The results indicated that maximum growth performance, apparent digestibility coefficient, body composition and haematological parameters were observed in 40 mg/kg Fe2 O3 -NPs supplementation. All the experimental diets were significantly improved (p < 0.05) in all the above parameters than control diet. In the present research, the recommended dosage of Fe2 O3 -NPs as dietary supplement is 40 mg/kg for improving the growth, nutrient absorption, body composition and haematological indices in C. carpio fingerlings. Hence, this study demonstrates the potential of NPs to improve the health of fish.

The enzymatic oxidation of sinapic acid catalyzed by horseradish peroxidase (HRP) or tyrosinase was investigated using model systems, which contained the pure compound or canola meal. Spectrophotometric scanning of pure sinapic acid solution in the presence of HRP (0.2 U) or tyrosinase (40.3 U) showed continuous decreases in absorbance at 304 nm over a period of 90 and 60 min, respectively. HPLC analyses of enzymatic end products, obtained by the catalysis with HRP or tyrosinase, indicated the presence of two main compounds (1 and 2). After alkaline hydrolysis of canola meal, sinapic acid that was released from sinapine was also converted to compounds 1 and 2 by HRP or tyrosinase. Enzyme reaction kinetics results indicate that the catalytic efficiency (CE = 0.538), reaction velocity (Vmax  = 5.67 ∆A/h), and Michaelis-Menten constant (Km  = 926.64 µM) of HRP are significantly higher than those of tyrosinase (CE = 0.041, Vmax  = 0.41 ∆A/h, Km  = 173.03 µM) at 50-250 μM pure sinapic acid concentrations. PRACTICAL APPLICATIONS: Canola meal contains a large amount of sinapine, which is the choline ester of sinapic acid, a strong antioxidant compound. However, the oxidation or decarboxylation products of sinapic acid could add value by increasing the level of electron-dense carboxylic and carbonyl compounds. In this study, enzymatic treatment of alkaline-hydrolyzed canola meal with horseradish peroxidase (HRP) and tyrosinase was investigated and shown to be suitable for converting sinapic acid into oxidized compounds. Therefore, the enzymatic treatment is a potential application for value-added processing of canola meal.

The aims of this study were to reveal the magnitude of the differences in protein structures at a cellular level as well as protein utilization and availability among soybean meal (SBM), canola meal (CM), and rapeseed meal (RSM) as feedstocks in China.
Experiments were designed to compare the three different types of feedstocks in terms of: 1) protein chemical profiles; 2) protein fractions partitioned according to Cornell Net Carbohydrate and Protein System; 3) protein molecular structures and protein second structures; 4) special protein compounds-amino acid (AA); 5) total digestible protein and energy values; 6) in situ rumen protein degradability and intestinal digestibility. The protein second structures were measured using FT/IR molecular spectroscopy technique. A summary chemical approach in NRC model was applied to analyze truly digestible protein.
The results showed significant differences in both protein nutritional profiles and protein structure parameters in terms of α-helix, β-sheet spectral intensity and their ratio, and amide I, amide II spectral intensity and their ratio among SBM, CM and RSM. SBM had higher crude protein (CP) and AA content than CM and RSM. For dry matter (DM), SBM and CM had a higher DM content compared with RSM (P < 0.05), whereas no statistical significance was found between SBM and CM (P = 0.28). Effective degradability of CP and DM did not demonstrate significant differences among the three groups (P > 0.05). Intestinal digestibility of rumen undegradable protein measured by three-step in vitro method showed that there was significant difference (P = 0.05) among SBM, CM and RSM, which SBM was the highest and RSM was the lowest with CM in between. NRC modeling results showed that digestible CP content in SBM was significantly higher than that of CM and RSM (P < 0.05).
This study suggested that SBM and CM contained similar protein value and availability for dairy cattle, while RSM had the lowest protein quality and utilization.

Canola meal has potential as a high protein food ingredient. The extrusion-induced changes in color, pH, extractable protein and in vitro protein digestibility of canola meal under different extrusion conditions was assessed. The extrusion barrel moisture (24%, 30% or 36%) and screw kneading block length (0, 30 or 60mm) were used as independent process parameters. Extrusion at high barrel moisture (36%) favored protein aggregation resulting in lower extractable protein compared to extrusion at the lowest barrel moisture (24%). At lower barrel moisture contents (24% and 30%), a longer kneading block length increased extractable protein but this was not the case at 36% barrel moisture. Canola protein digestibility was improved upon extrusion at 30% barrel moisture but there was no significant change at lower (24%) or higher (36%) barrel moisture. The kneading block length of the screw had no significant effect on the canola protein digestibility within the same barrel moisture level. The relationship between the physico-chemical parameters and in vitro digestibility was examined. This study highlighted the complex interplay of extrusion processing variables that affect protein degradation and the interaction of components, with consequent effects on protein digestibility.