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


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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.