Rice bran is the very thin layer of brown rice and most nutritious part. It is bestowed with high amounts of vitamins and minerals. Rice bran oil is also used in cosmetics because of its moisturising properties. Rich in vitamin E, it flows smoothly and penetrates well and does not stick on to the skin. It is greatly valued as an excellent carrier oil. Rice bran oil is manufactured from the inner husk and germ of brown rice. It has a mild nutty and neutral taste and stable when exposed to high temperature.
Rice bran oil is extracted by chemical solvent process or pressed directly from rice bran. For a minimal amount of oil extraction expelling pressing method can be used while large scale manufacturing uses solvent making technique. Hot extraction process gets more oil yield and pure edible oil than the cold processing. The three main steps involved in rice bran oil extraction include:
Raw material preparation – Rice bran oil extraction- Crude oil refining
Raw Material Preparation
Rice bran is initially screened, graded and sorted which are then heated at a temperature higher than 100 C by steam to prevent lipase hydrolysis reaction in rice bran before the extraction process.
The crude rice bran oil is extracted either by mechanical method with oil presser or by chemical method with solvent extraction. The rice bran is completely stabilized where oil is removed producing two products a high-quality crude rice bran oil and defatted rice bran.
Rice Bran Oil Refining
The crude rice bran oil obtained is further processed to remove the free fatty acids and offers an oil with less processing suitable for agricultural purposes. Edible oil which is bleached leaves mild flavour and smell and it must be removed by steam distillation before final packaging.
This is the final step in the process of extracting rice bran oil where residual free fatty acids and any undesirable flavours are removed from the oil. The fully processed oil is ready for packaging into retail bottles, food service pails or large storage container.