In the production process of structured lipids, the influence of the addition of antioxidants before enzymatic acidolysis was investigated. Eight different antioxidants were screened: butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, ascorbyl palmitate, citric acid, EDTA, a tocopherol blend and lecithin. As substrates, oils with different degrees of unsaturation (rapeseed, safflower or fish oil) as well as caprylic and capric acids were used. Enzyme activity (measured as percent incorporation of caprylic/capric acid into the oils) was not significantly influenced by the addition of antioxidants, neither in a batch process nor in a packed-bed reactor operation. a-Tocopherol concentrations remained stable for those mixtures where tocopherols were added. Primary oxidation products (measured as peroxide values) were reduced after acidolysis in the packed-bed reactor, likely due to the adsorption in the enzyme bed. The study shows that the addition of antioxidants before enzymatic reactions has no negative effects on the reaction progress. None of the antioxidants chosen had a significant positive effect on either the reaction process or the oxidative status of the structured lipid produced.
European Journal of Lipid Science and Technology, 2005, Vol 107, Issue 7-8, p. 464-468