Tocopherols and tocotrienols as antioxidants for food preservation

The number and position of methyl groups of tocopherols and tocotrienols influence their ease to donate hydrogens and hence their antioxidant effectiveness. Tocopherols have been found to increase the induction period of bulk oils and emulsions, but their relative activity was found to differ under different conditions. There are several peculiarities regarding the antioxidant efficacy of tocopherols, e.g. the immediate changes from induction to propagation period, their loss of efficacy at higher concentrations and the unknown mechanisms behind their synergistic interactions with secondary antioxidants (e.g. phospholipids and amino acids). The recent understanding of the role of the physical factors, e.g. the log P value and size and orientation of antioxidant molecules help to understand these peculiarities.