A measure of hydroperoxides in oxidised oil. These are measured quantitatively on the basis of their ability to liberate iodine from acidic solutions of potassium iodide. This can be measured by titrating with sodium thiosulphate solution or electrochemically. The value is quoted as mmol of available oxygen per 2 kg of fat. Standard methods are described by AOCS [Cd 8 53(89)] and IUPAC (2.501).
E.N. Frankel, Lipid Oxidation, The Oily Press, Dundee (1998).