What is the process involved in the manufacture of DHA/EPA rich fish oil?

Dear SR,

A vast array of processing technologies are available for the production of fish oil concentrates containing DHA and/or EPA enriched preparations. These include extraction and separation technologies, various filtration and refining processes, 'winterization', toxicant removal in some cases, conversion of the natural triglyceride form to ethyl esters of omega-3 fatty acids followed by molecular or vacuum distillation, subsequent transesterification, to name but a few of the approaches used in the industry. Beginning with a high quality natural fish oil is an important first step in contributing to the eventual production of a high quality omega-3 concentrates enriched in DHA, EPA, and various ratios and mixtures thereof.