Manufacture of edible oil: Solvent extraction

Material containing low amount of oil such as oilseed cake (meal) and rice bran are suitable for solvent extraction. Hexane is most widely used solvent and this process can extract oil form feed until oil present in feed is reduced to 0.5 % or less.


Perforated basket attached in conveyor belts holds the feed. Fresh warm solvent is sprayed from the top. Hexane is used as solvent whose boiling point is nearly 60°C. The basket moves up carrying the feed which is extracted through screen at the bottom of basket. The residue is treated with fresh solvent and finally defatted cake is obtained. The half miscella is recirculated through pump and again comes in contact with solvent. The full miscella is evaporated, refined, bleached and deodorized to obtain refined bleached and deodorized (RBD) oil.


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Manufacture of edible oil: Screw press method

Extraction of fat from different sources like oilseeds, nuts, oil containing fruits, animal fat are different and use different techniques.

  1. Animal fat is extracted by rendering technique that uses heating (moist/dry) fatty tissue.
  2. Oil from oilseeds and nuts is extracted by using mechanical expellers (screw press) that can extract 90 – 95 % oil in seed.
  3. Oil from oil cakes and bran is extracted by solvent extraction using hexane as solvent.
  4. Oil from flesh of fruits is extracted by using hot water extraction technique where flesh of fruit is macerated in hot water and extracted oil can be recovered by settling or centrifugation method.

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