Total Oxidation (TOTOX) Value in Oils

During storage, the effects of physical and chemical factors such as oxygen, metal ions, temperature and light lead to deterioration of oils. This affects the oil quality. The most critical value in terms of quality in oils is the oxidation level. In order to determine the oxidation level of oils, primary oxidation products are calculated by hydroperoxidases by the peroxide number method, while secondary oxidation products are calculated by measuring the P-Anisidine value.

P- Anisidine value can be used as an approximate measure of the stability of freshly processed oils in storage. While the peroxide number serves to detect the first products in lipid oxidation, P-Anisidine measures the secondary products (aldehydes and ketones). To find the maximum level of oxidation products in the same oil, the total oxidation (totox) value is calculated.

The quality values of edible oils are determined by the “Totox Value”. It is calculated using peroxide and p- anisidine value.
Totox Value= 2 X Peroxide Count + P-Anisidine value.

In line with the studies carried out, the critical limits of oils are; reported as <5 mEq/kg for peroxide number, <20 for P-Anisidine value and <26 for totox value.

Totox value takes into account the instant status of the product (using the peroxide number) and its history (P-Anisidine value). Accordingly, the differences in the totox value are more important than the individual values. Although this method has been known for a long time, there is no limit or official standard quality criteria for oils.