The refining process of rice bran oil involves several steps:
1. Degumming: In this process, phospholipids are eliminated from the crude rice bran oil1. This can be achieved through Acid DE-Gumming or Enzymatic DE-Gumming.
2. Pre-Bleaching: The degummed rice-bran oil is heated and then a pre-calculated amount of bleaching earth is added. This mixture is then transferred to the bleacher.
3. Dewaxing: The oil is cooled slowly and steadily to crystallize the wax for easy filtration1. This process involves cooling the oil at a temperature where wax converts into a solid form (actually in slurry form) while the oil remains in liquid form.
4. Neutralization: This step involves reducing excess free fatty acid from the oil.
5. Decolorization: The color of the oil is decreased with activated clay.
After these steps, the refined rice bran oil is ready. It’s clear, transparent, and reddish-yellow in color. It’s suitable for high-temperature cooking methods such as stir frying and deep frying.
There are also some information available online that provide a visual guide to the rice bran oil refining process: https://ricebranoilpress.com/