Peroxide value definition: a measure of the concentration of primary oxidation products in fats and oils, expressed in milliequivalents of active oxygen per kilogram, used to assess rancidity development in nuts, seeds and edible oils and to verify freshness at intake.
In trade practice
Buyers of sunflower oil, cold-pressed seed oils and nut kernels specify a maximum peroxide value in the purchase specification and require the supplier to provide a certificate of analysis from an accredited laboratory for each batch. At intake, QA teams may conduct confirmatory testing, particularly for products with long transit times or where cold-chain continuity is uncertain. Rising peroxide values during storage indicate oxidation is progressing, so storage conditions including temperature and oxygen exposure are critical. A common error is accepting a certificate of analysis dated at production without considering the elapsed time and storage conditions before arrival.
In a specification
A specification should state the maximum permitted peroxide value, the test method and the point in the supply chain at which the limit applies, whether at production, at dispatch or at intake.