The groundnut should firstly be pretreated by professional seed cleaning equipment. Then the cleaned peanut seeds are sent to the oil milling plant to be pressed into oil by oil presses. However, the crude peanut oil usually contains a number of impurities.So for edible oil, the pressed groundnut oil needs to be extracted in the oil extraction plant before the extracted oils are sent to the oil refining plant for further processing.
Groundnut oil pressing process:
Pressing groundnut oil is made by squeezing method, and the leaching groundnut oil is made by solvent extraction.
Due to the high residual oil rate of the pressing process, the content of residual oil is about 6%-8%. Large oil mill usually use a pre-squeezing leaching process to produce groundnut oil.
Pre-squeezing leaching process is first squeezing the most of oil, and the groundnut cakes are performed for solvent extraction, further extract the oil left in the oil cake, and increase the oil output rate of the oil.
Groundnut cake solvent extraction process:
The solvent extraction equipment can reduce the residual oil in the cake to within 1%, the quality of the cakes is improved, and the protein and other substances in the cake can be better retained.
Groundnut crude oil refining process:
The crude groundnut oil is processed through refining equipment to remove gum, free fatty acids, water, pigment, odor, wax, solvent residue and other impurities in the oil, to ensure the safety of edible oil and improve the quality of the end oil.
The squeezing process retains the original flavor and nutrition of the groundnut oil, which can be processed into a fragrant peanut oil with physical refining.The fragrant groundnut oil process is mixing the extraction oil from groundnut kernel roaster and steaming cooker. The main equipment include seeds roaster, screw presses, filter machines, refining system, and low-temperature filtration equipment.
The refining workshop uses a low temperature process, twice filtering and cooling, generally does not perform hydration, alkaline refinery, decolorization and deodorization, fully retain the original flavor of groundnut oil.