Study on Vitamin A Acetate Reaction Initiated by Peroxide

Abstract

Vitamin A acetate is used in fortified food widely. Due to the conjugated double bonds and ester functional group, it is susceptible to light, heat, oxygen and peroxide, resulting in changes in molecular structure and performance. The impact of peroxide on vitamin A acetate in octane solution with the addition of isopropylbenzene hydroperoxide (CHP) in the absence of light and oxygen at 90°C was investigated. By means of HPLC-DAD, GPC and HPLC-MS, it was found that vitamin A acetate was depleted after reaction for 18 days, and the main products were dimers. The reaction mechanism was proposed as follows: CHP homolysed to free radicals, and then abstracted α-H from vitamin A acetate to generate vitamin A acetate free radical, which added to another vitamin A acetate to form dimer free radical, at last dimer free radical abstracted α-H from vitamin A acetate molecule to form dimer product. Furthermore, four most probable dimer product structures were elucidated.