Oxidative stability of DHA oil during the refining process

The composition and oxidative stability of DHA oil was investigated during the refining process (deguming, alkali refining, bleaching and deodorization) .It was found that all of minor compounds decreased during the whole process.The order of oxidative stability of DHA oil against light was deodorized>bleached>crude/degummed>alkali refined oil.The order of oxidative stability of DHA oil against heat (Rancimat method) was bleached>deodorized>degummed>crude>alkali refined oil.The oxidative stability of DHA oils before bleaching step was poor because of too many prooxidants in oils, and the deodorized oil was less stable against heat due to the loss of antioxidants in the deodorization.