Hydrogen peroxide, bleaches optimization

In an optimally controlled process free from transition-metal ions hydrogen peroxide bleaching is remarkably safe, there being no reported detrimental effects of bleaching at around 100 °C or for more than several hours [143]. Under such conditions, most of the peroxide appears to be consumed in the oxidation of chain end units of the cellulose macromolecule. The other major effect on the substrate is oxidation of secondary hydroxy to keto groups, accompanied by the formation of very few aldehyde or carboxyl groups [235]. 

Peroxide is thermodynamically unstable but kinetically rather inert and this explains the need for time or temperature to achieve effective bleaching. As a general rule, the bleaching performance of persalts increases as the pH is raised [i.e., as more OOH is generated (piC, of hydrogen peroxide is 11.6)]. Loss of actives due to transition metal action or thermal instability may alter the pH of maximum activity in practice. The optimal conditions for maximum activity of activated systems are discussed in Sec. IV. 

Peroxide value (POV). The POV of lecithin, produced from fresh or optimal stored beans or seeds, is usually below 2 meq/kg. In contrast to POV values in oil as a result of oxidation, the POV in lecithin is mostly a result of residual hydrogen peroxide from the bleaching process step. 

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