Lipid oxidation involves the continuous formation of hydroperoxides as primary
oxidation products that may break down to a variety of nonvolatile and volatile
secondary products (8, 15). The formation rate of hydroperoxides outweighs their
rate of decomposition during the initial stage of oxidation, and this becomes
reversed at later stages. Therefore, the peroxide value (PV) is an indicator of the
initial stages of oxidative change (18). However, one can assess whether a lipid
is in the growth or decay portion of the hydroperoxide concentration by monitoring
the amount of hydroperoxides as a function of time (7).
Analytical methods for measuring hydroperoxides in fats and oils can be classi-
fied as those determining the total amount of hydroperoxides and those based on
chromatographic techniques giving detailed information on the structure and the
amount of specific hydroperoxides present in a certain oil sample (8). The PV represents
the total hydroperoxide content and is one of the most common quality indicators
of fats and oils during production and storage (9, 18). A number of methods
have been developed for determination of PV, among which the iodometric titration,
ferric ion complex measurement spectrophotometry, and infrared spectroscopy
are most frequently used (19).