How is Sesame Oil Refined?

Sesame oil refining often involves multiple steps to improve its characteristics, although high-quality seeds may produce oil that needs minimal processing.

Here's a breakdown of the typical sesame oil refining process:

• Solvent Extraction (Optional): Some manufacturers use solvents (like hexane) to extract the remaining oil from the sesame seeds after pressing. This increases the yield.

• Degumming/Neutralization: This process removes gums, phospholipids, and free fatty acids, which can affect the oil's stability, flavor, and appearance. This is typically achieved through:

  • Acid Treatment: Adding phosphoric or citric acid to hydrate the gums and free fatty acids.
  • Centrifugation or Sedimentation: Separating the hydrated gums and fatty acids from the oil.
  • Alkali Refining: Neutralizing free fatty acids with an alkali solution (like sodium hydroxide).

• Bleaching: Bleaching removes pigments and other impurities, improving the oil's color and clarity. This can be done using:

  • Activated Clay/Carbon: These materials adsorb impurities and pigments.
  • Heating: The oil is heated and mixed with the bleaching agent, followed by filtration to remove the spent bleaching material.

• Deodorization: This step removes volatile compounds that contribute to unwanted flavors and odors.

  • Steam Distillation: The oil is subjected to high-temperature steam under vacuum, which strips out the volatile compounds.

Table Summarizing the Sesame Oil Refining Process

It's important to note that not all sesame oil undergoes all these steps. Cold-pressed sesame oil, for instance, often avoids extensive refining to retain its natural flavor and nutritional properties. The choice of refining method depends on the quality of the sesame seeds and the desired characteristics of the final product.