PROCESSING OF OILSEEDS
In India oilseeds like groundnut, mustard, safflower, are more commonly grown for edible oil purpose.

Oil extraction: The oilseeds are cleaned, dehusked and oil is extracted by mechanical pressing, screw pressing, prepress solvent extraction and direct solvent extraction.

Protein isolate: After solvent extraction, it is treated with dilute sodium hydroxide at pH8. The proteins are separated by filtration and washing with water and then used for different purposes.

Groundnut

Groundnuts resemble other pulse in general nutritive value, except that they are rich in fat. Groundnuts are boiled or roasted and consumed. But the chief product is the oil, which can be used either as cooking oil or for making margarine and soap. The secondary product is the residue or cake left after the expression of the oil. It is also purified and used in supplementary mix. The major proteins of groundnut are arachin and conarachine which is lacking in lysine and methionine and its quality can be improved by either adding these amino acids or foods rich in the same.

Extraction of Sunflower Oil    

Both solvent extraction process and mechanical expression methods are in use for the extraction of oil from the sunflower oilseeds. In the expression of oil by the screw press, 60 to 70% of the oil from the meal is recovered. The operations and the processes followed for the mechanical extraction of oil using a screw press is outlined below. 
The oilseeds are cleaned to remove all foreign materials including stones, metals and dust from the seed.
Then dehulling of the clean seed is done to reduce the fibre content and increase the oil and the protein contents in the dehulled kernel.  
The kernels are then allowed to pass through the roller mills to reputre the seed and increase the oil recovery efficiency. 
The rolled flakes are then cooked by heat treatment for further increase in oil recovery.
The oil from the cooked, flaked is extracted by pressing the cooked flakes in the expellers. The oil is then filtered to remove the seed particles. 
The sizes of the deoiled cakes are reduced and then these are bagged for storage.
The crude oil is refined for the production of edible grade oil.