Here the details about Process of Physical refining of oils & Fats.
To make a hardened vegetable oil for use in creating margarine or shortening, it is common to practice hydrogenating vegetable oils. Hydrogenation scents, which are exceedingly objectionable, are a major problem with this treatment. A product like margarine cannot be made without removing these scents from hydrogenated oils, as they are responsible for the disagreeable ...