VEGETABLE OILS’ REFINING
Citric acid E330
Citric acid is edible. It is mainly used as a flavoring and preservative in foods and beverages,
especially soft drinks and candies. In some applications it acts as a pH regulator.
Chemical Formula : C6H807 CAS Number: 77-92-9
Phosphoric Acid 85% Food Grade E 338
Food grade phosphoric acid is used to acidify foods and beverages, such as sodas and jams. Also used
as a disinfecting agent in the dairy industry and other food industries such as Vegetable Oil Refining.
Chemical Formula: H3PO4 CAS Number: 7664-38-2
Caustic Soda
Caustic soda, also known as sodium hydroxide (NaOH), is used in the refining of vegetable oils. It is
commonly used to neutralize the free fatty acids present in crude oils. This process, called
neutralization, helps remove acidic impurities and stabilize the vegetable oil. Caustic soda reacts with
the fatty acids to form sodium salts, which are then removed from the mixture. This contributes to
improving the quality, stability, and shelf life of refined vegetable oils.
Chemical Formula: NaOH CAS Number: 1310-73-2.
BLEACHING EARTH
Bleaching earth, also known as activated clay or fuller's earth, is commonly used in the refining of
vegetable oils. It is a natural adsorbent material that helps remove impurities, pigments, and
unwanted substances from the oil through a process called bleaching.
During the vegetable oil refining process, bleaching earth is added to the oil and mixed thoroughly.
The bleaching earth acts as a filter, adsorbing impurities and color-causing substances from the oil.
This helps improve the appearance, clarity, and stability of the oil.
Bleaching earth is particularly effective in removing unwanted substances such as chlorophyll,
carotenoids, residual pesticides, and oxidation products. It plays a crucial role in achieving the
desired quality and purity of the refined vegetable oil.
Among the most well-known bleaching earths used in vegetable oil refining is attapulgite, which is
primarily composed of hydrated aluminum and magnesium silicate.
Approximate Chemical Formula of Attapulgite: (Mg,Al)_2Si_4O_10(OH)_4•4H_2O.
CAS Number of Attapulgite : 12174-11-7.
ACTIVATED CARBON
ACTIVATED CARBON :
Activated carbon, also known as activated charcoal, is used in the refining of vegetable oils. It is a
porous material that has the ability to adsorb impurities, dyes, and undesirable compounds present
in the oil.
During the vegetable oil refining process, activated carbon is added to the oil and mixed to allow for
effective adsorption of unwanted substances. Activated carbon acts as a filter by trapping impurities
and harmful compounds, such as pigments, pesticide residues, aromatic compounds, and organic
contaminants.
The use of activated carbon in the refining of vegetable oils helps improve the purity, clarity, and
stability of the oil. It helps eliminate unwanted odors, tastes, and potentially harmful compounds,
resulting in a higher quality oil.
It is important to note that the activated carbon used in the refining of vegetable oils is specially
designed for this application and is typically of plant origin. It is selected for its high adsorption
capacity and compatibility with food safety standards.