Factors affecting vitamin degradation in oil-in-water nano-emulsions

Fat fractions composed by different proportions of low (LMT) or high (HMT) melting temperature triacylglycerols were used, alone or in mixture with alpha-tocopherol for the preparation of oil-in-water protein stabilised nano-emulsions. Addition of alpha-tocopherol to the LMT or HMT fat fractions was accompanied by different changes in the emulsion characteristics such as fat droplet size distributions, under-cooling and polymorphic transitions, in parallel with different extent of alpha-tocopherol degradation reactions. Our results showed higher immobilisation pattern of alpha-tocopherol molecules and higher protection against degradation when incorporated in higher size fat droplets, which presented 2L(alpha) -> 2L(beta') polymorphic transitions under cooling and re-heating cycles.