Corn Oil Refining

Extremely nutritional corn oil also known as maize oil is extracted from the germ of the corn. It is commonly used as cooking oil but its high smoke point makes it highly valued frying oil. Apart from cooking, refined corn oil is also used in the preparation of margarine.

The refining process removes these unwanted harmful elements from the crude oil and imparts few of the most valuable qualities which include pleasant taste and resistance to smoking, discoloration, developing flavors. Let’s have a look at the refining process of corn oil.

Process of Refining Corn Oil

Crude Corn oil is refined through alkali neutralization process which is a chemical refining process and involves numerous steps. The major steps involved in refining of crude corn oil through alkali neutralization are -

  • Gums conditioning Neutralization
  • Bleaching
  • Winterization
  • Deodorization

Let’s know the each processing step in detail, one by one -

Fatty ACID Composition

Gums conditioning & Neutralization

In this process, the crude oil is first treated with acid (citric acid/ phosphoric acid) followed by treatment with alkali to neutralize the oil which is followed by soap separation. Further the soap separated oil is washed from hot water for removing the traces of soap, later dried for obtaining neutralized oil.

This process further involves four steps listed below -

  • Conditioning - in this step, non-hydratable phospholipids are transformed into their hydratable form by breaking down the phosphatide/metal complexes by using a strong acid.
  • Neutralization - free fatty acids are neutralized by an alkali for creating the sodium salt of free fatty acids
  • Washing - in this step, residual soap is removed by washing it from the hot water.
  • Drying - in this step, the leftover moisture is removed from the oil under vacuum.


This process removes the color pigments, polycyclic aromatic compounds, dirt, trace metals, phospholipids and other impurities through the interaction of the absorbent with oil or fat in order to improve its quality. At first, the oil is heated, and then bleaching clay is added to the oil at the atmospheric condition as it helps to utilize the moisture of bleaching earth for a better outcome.

Further, the oil is heated in the separate heater which works under vacuum. After heating, the oil is sent to the bleaching reactor for decolonization & purification purpose.

This processed oil is then filtered through filtering equipment specially designed for the suitable flow of bleaching earth mixer and oil.


In this process, the higher melting point parts such as saturated triglycerides and waxes are removed from the oil. The vegetable oil is slowly cooled and saturated glycerides are crystallized. This process consists of fractional crystallization of fats and oil which is further followed by solid-liquid separation through filter.

De-Acidification Cum Deodorization

This is the last step of edible oil refining in which a certain amount of stripping agent is passed through hot oil for a certain period of time at quite a low pressure. The pre-treated oil is further processed for removing fatty acids, odour and other constituents.

This process is carried out at high temperature as well as under high vacuum along with sparging steam. This process removes the remaining free fatty acids and odoriferous compounds making the oil fit for human consumption. This process generally has two effects on oil -

Advantages of Mectech Corn Oil Refining Plant

Mectech - the leading edible oil refining company provides the refining plant for the corn oil with many advantages over other plants. Let’s have a look at the advantages of Mectech Corn Oil Refining Plant -

  • The entire process of neutralization is so efficiently designed that it neutralizes the fatty acid with minimal saponification as well as minimizes the content of phosphorous in the neutral oil.
  • The unique design of caustic lye mixer in neutralization section offers an excellent contact amid caustic lye and oil which ensures the minimal consumption of caustic in the process of neutralization.
  • In addition, the caustic and oil retention tank in neutralization section provides a variable residence time ensuring minimum loss of neutral oil.
  • Mectech’s uniquely designed bleacher doesn’t require any mechanical agitation and the bleaching process is conducted under moisture content.
  • In addition, it also consumes low bleaching earth and also results in saving in power consumption.
  • Efficiently designed cooling system as well as the crystallizer which offers nucleation even at high temperature. If the nuclei are formed at high temperature, the crystal size below equilibrium temperature becomes large.
  • The oil to oil heat exchanger in deodorizing section is efficiently designed in such a way that it ensures the minimum requirement of the heat energy.
  • The fatty acid scrubbing system in deodorizer has efficient and the elaborate design which ensures that there is no leftover fatty acid in the barometric condenser.
  • The heating coil is also efficiently designed which avoids charring of oil during the entire refining process.
Call us !
+91-(0124)-4700800 (30 lines)