Introduction To Corn Oil Processing Technology
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 flavours. 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
Gums Conditioning And 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 involves following steps as listed below
- Conditioning: in this step, non-hydrate able phospholipids are transformed into their hydrate able 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 colour 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 And 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.