Analysis of peroxide value in olive oils with an easy and green method

A green, easy-to-use, and sensitive spectrophotometric iodide-dependant method for the quantitative determination of the lipidic hydroperoxides in virgin olive oils was developed. Virgin olive oils were added with 0.5% HCl-ethanol, with a saturated KI solution and, after incubation, the resulting solution was filtered. Hydroperoxides were determined indirectly by reading the absorbance of the generated triiodide at 350 nm; the total time of analysis was about 7 min. A good linearity (with correlation coefficient (r) of 0.9997) of the calibration curve was obtained with purified olive oil spiked with tert-butylhydroperoxide at levels ranging from 1.0 to 10.0 meqO2/kg, with variation coefficients less than 5% (n = 3) and limit of detection and quantification of 0.3 and 0.9 meqO2/kg, respectively. Results obtained with the spectrophotometric method showed good correlation with those obtained with the official method with a r of 0.9819 confirming the reliability of the developed method.