Stability of tocopherols in adapted milk-based infant formulas during storage

An evaluation is made of the effects of added alpha-tocopherol (alpha-T) or alpha-tocopherol acetate (alpha-TAc) combined with iron lactate or sulfate, storage time (up to 17 months) and storage temperature (22degreesC and 37degreesC) on the alpha-TAc, alpha-T, gamma-tocopherol (gamma-T) and delta-tocopherol (delta-T) content of infant formulas. Tocopherols were measured by normal phase HPLC and fluorescence detection after direct extraction, which allows the determination of both alpha-TAc and alpha-T. The alpha-TAc content was not affected by temperature or storage time, although the alpha-, gamma- and delta-T contents, which were lower at 37degreesC than at 22degreesC, were significantly affected. The type of iron salt added (lactate or sulfate) exerted a significant effect on the alpha-T and alpha-TAc content. By the end of the storage period studied, all tocopherols had decreased by greater than or equal to50%, although the total vitamin E activity exceeded 0.1 alpha-T equivalents 100 kJ(-1), i.e., the minimum content established by European law. (C) 2004 Elsevier Ltd. All rights reserved.