The effect of hydrogen peroxide bleaching of canola meal on product colour,dry matter and protein extractability and molecular weight profile

The aim of this study was to bleach canola meal by hydrogen peroxide to understand the treatment effect on product colour, dry matter and nitrogen extractability. Meal suspensions at 2.5%, 5% and 10% (w/v) were treated in 3, 6 and 10% H₂O₂ at pH 3, 7 and 10. The bleached meal was extracted under acidic and alkaline conditions. The results showed a high bleaching effectiveness of canola meal by H₂O₂. The L* parameter was increased from 47.18 ± 0.56 up to 86.80 ± 1.05. Effect of pH was significant and the highly bleached meal was obtained at pH 10. Extractability of dry matter was increased when the meal was treated with H₂O₂, from 26.87 ± 0.10% for the control meal up to 83.20 ± 0.59% for the meal treated in 10% H₂O₂ in a 2.5% (w/v) suspension. Sodium dodecyl sulphate‐polyacrylamide gel electrophoresis showed a depolymerisation effect of H₂O₂ on the high molecular weight proteins.