Reactions of phosphoric acid in the autoxidation of fats

At the elevated temperatures used in accelerated stability tests phosphoric acid was shown to react with fatty peroxides in such a manner as to prevent their estimation by the usual iodometric methods. A dark, phosphorus-containing precipitate formed, which was apparently polymeric in nature. Phosphoric acid also reacted with oxidized fat to form an undisassociated fat-soluble complex but did not react with fresh unsaturated fatty esters. In addition to the well known sparing action of phosphoric acid ona-tocopherol, it was shown thata-tocopherol and quinone also exerted a marked sparing action on the phosphoric acid.