Copper Mediated Autoxidation of Vitamin A in Food

Vitamin A (retinol) was fortified to microcrystalline cellulose (MCC) and exposed to oxidative decomposition in the presence of copper ion under different storage temperatures at water activity (aw) 0.11. It was observed that copper ion and temperature had great effect on the stability of vitamin A. About 50% of the fortified vitamin A was lost in 41, 34 and 24 hours when stored at 30, 40 and 50°C, respectively at aw 0.11. The rate of reaction associated with copper ion was of first order character. The 'k' value was the highest at 30°C followed by 40°C and the minimum rate at 50°C. Model system (MS) fortified with copper ion had a lower activation energy (Ea) value (20.1x10³ Jmol-¹) as compared to unfortified MS, which had an Ea value of 28.4x10³ Jmol-¹.