Seed Oil Extraction Process
Cottonseed oil, like other
, is extracted from the seed of the plant, through either mechanical processes such as crushing or pressing, or by chemical processes such as solvent extraction. Cottonseed oil however, is most commonly extracted commercially via solvent extraction.
Seed Crushing / Cold Press Extraction
Cold press extraction is one of the methods of mechanical extraction as well as required less energy than other oil extraction techniques and also environmental friendly. It is used to extract oil from a range of matrices and is produced especially in the oil production from oilseeds. High-quality oils can be obtained by performing production at low temperatures using cold press method. It has an environmentally friendly use with no solvents. In other words, the cold-press extraction does not involve either heat or chemical extraction. The soybean, sunflower, rapeseed, corn, grape seed, hemp, flaxseed, rice, bran, olive and pumpkin oils were obtained by cold press extraction method. Moreover, these oils are interesting for consumers due to their natural and safe as well as prevent certain diseases and improve human health due to including a higher level of lipophilic phyto chemicals such as antioxidants. These oils have better nutritive properties than refined oils. However, they have a lot of advantages, one of the disadvantages of this technique is low productivity. Another disadvantage of this technique is hard to extract same quality product. The cold pressed oils can add to food as natural antioxidative additives due to phytochemicals and as fatty acid supplements due due to invaluabile double bond fatty acid. There are several studies to investigate the other chemical compounds in the oils and try to use in food products.
Solvent Extraction Process
Solvent extraction is a chemical oil extraction method to process oil out from vegetables, oilseeds and nuts by solvent, and Hexane is the preferred choice. Industrial oil processing for the edible oil generally involves the solvent extraction step which may or may not be preceded by pressing. Hexane-based processes have been in commercial operation for a long time. For such processes, it is possible to achieve oil yields in excess of 95% with a solvent recovery of over 95% which in compare to 60 to 70% oil yield by mechanical expeller pressing method . The solvent extraction method will remove all but about ½% of residual oil, uses less hp, and requires less maintenance. It is relatively efficient and reliable.