# What does peroxide value exactly measure?

I understand that peroxide value gives a measure of the extent to which an oil has undergone oxidation, however, I looked and couldn't find any source which explains the chemistry behind PV value. More specifically, how is pv value related with oxidation?

Wikipedia states that "the peroxide value is determined by measuring the amount of iodine which is formed by the reaction of peroxides (formed in fat or oil) with iodide ion." But what is the reaction of the peroxides? And how is it related with oxidation?

Thank you

The test measures the amount of hydroperoxide by a redox reaction with iodide:

$\ce{2ROOH + 2H+ +2I- -> 2ROH + I2 + H2O}$

In the course of the reaction, the hydroperoxide is reduced, while iodide is oxidized to iodine. In principle, this is a variation of the iodine clock reaction of hydrogen peroxide.

• How does this show oxidation? – sepehr78 Jan 19 '17 at 12:11