Edible Oil Refining Technology

​Process ​Purpose ​Technical points

​Degumming Remove phospholipids and proteins Add phosphoric acid aqueous solution and centrifuge
​Deacidification Neutralize free fatty acids Alkali refining (NaOH solution) or steam distillation
​Decolorization Adsorb pigments (chlorophyll, carotene) Activated white clay/attapulgite adsorption, temperature 120-140℃
​Deodorization Remove odorous substances (aldehydes, ketones) High temperature (230-260℃) vacuum distillation
​Dewaxing Remove wax (required for rice bran oil) Frozen centrifugation (temperature 5-10℃)

Physical refining (applicable to high acid value oil)
​Principle: Deacidification directly through steam distillation, no need to add alkali.
​Advantages: Reduce soap stock production, suitable for palm oil and animal oil.
​Equipment: Molecular distillation device (high investment cost).
​Post-treatment
​Water washing after deacidification: Remove residual soap stock and adjust the pH value to neutral.
​Cooling filling: Cool to below 30℃, nitrogen-filled packaging to prevent oxidation.
Refining type Applicable oils ​
​Chemical refining: soybean oil, rapeseed oil ​Physical refining: palm oil, rice bran oil ​Enzymatic refining: high phospholipid oil (such as sunflower oil)