A novel method for determining peroxide value of edible oils using electrical conductivity

In this study, a new method for determining peroxide value (PV) of edible oils was described. The basis of this method was the determination of changes in the electrical conductivity (EC) values of the aqueous phase during the reaction of potassium iodide (KI) with the hydroperoxides presented in oil samples. The effect of various analytical conditions was evaluated, such as temperature, holding time, oscillating time, stability of the saturated KI solution and oil types. The calibration was developed and validated using the EEC, AOCS, IUPAC, and AOAC methods. The results showed that the analytical conditions had no significant (P> 0.05) influence on the EC determination at room temperature; the calibration equation of PV was obtained as y = 150.54x - 0.0327 (where x is the change in EC values, S/m; y is PV, mmol/kg), with R = 0.9980 and SD = 0.4045. The linear correlativity between the proposed method and AOCS method was very high (R = 0.9992), and the standard deviation of the blind samples used in the experiments was slightly better than that of the EEC, AOCS, IUPAC, and AOAC procedures, which illustrates the feasibility of determining PV of edible oils using the proposed method. (C) 2013 Elsevier Ltd. All rights reserved.