1997 Volume 46 Issue 6 Pages 671-682,714
A novel method using isooctane was established for determining the peroxide value (PV), widely used as basis for assessing the rancidity of oil and fat. This was done through the collaboration of 10 research organizations by potentiometry using an automatic titrator equipped with a platinum complex electrode.
The potentiometric PV method gave a 10% higher value than by the official method of the Japan Oil Chemists' Society using isooctane (JOCS-I method) for samples with PV from 0.5 to 100 meq/kg. PV determined by the present method gave values quite consistent with those by the JOCS-Chloroform (JOCS-C) method.
Sample amounts in the JOCS-I method are 5 g for PV less than 10 meq/kg and 0.5 to 5 g for PV more than 10 meq/kg. By the present method, sample amounts were 2.0 to 5.0 g for PV less than 1 meq/kg, 0.1 to 2.0 g for PV from 1 to 100 meq/kg, and less than 0.1 g for PV more than 100 meq/kg. The present method is thus shown to have 5 times the sensitivity and accuracy of the official JOCS-I method. It is less time and labor consuming and oil/fat quality can be better controlled.
Any automatic titrator commercialized from 4 representative manufacturers in Japan may be used for the present potentiometric PV determination.
