In this post, we will explore the various stages involved in oil processing. Oils are extracted from seeds, cereals and nuts. Usually they undergo refining to remove dirt and unwanted particles. They include:
Extraction-This stage involves crushing , heating and flaking.
Pressing-After extraction, the seeds and nuts are pressed to remove approximately 60%-80% of oil.
Solvent extraction-This phase involves the use of two immiscible liquids, usually hexane that dissolves the oil.
Degumming-It incudes the mixing of the oils with acids such as malic acid and citric acid to extract the phospholipids, which may cause precipitation due to their moisture content.
Neutralization-Sodium hydroxide solution is added to the oil to remove oil components such as waxes and fatty acids that contribute to unwanted taste.
Bleaching-The colour pigments are removed in a vacuum at temperatures 0f 100C.
Filtration-To further purify the oil, it is passed through filters to remove any impurities.
After the oil processing from seeds and nuts, different types of oils are produced such as canola oil, corn oil, palm oil sunflower oil, peanut oil etc.