Edible Oil Processing

Background of Edible Oil

Edible oil falls into two categories, in this article, we mainly focus on  the first one.

• Vegetable oils which are obtained by processing soybeans, olives, coconuts, corn, peanuts, sunflower seeds, cotton seeds, sesame seeds, flax seeds and safflower seeds etc.
• Animal oils and fats which are rendered from the trimmings of freshly slaughtered animals.

Edible Oil Processing Process

Edible oils are recovered by grinding, cooking, expelling and pressing, or by solvent extraction of the raw materials. Generally speaking, there are three main process you should follow in the entire edible oil processing process.

Seed Preparation: The prime task of any seed preparation plant is to process seeds in such a way that under normal circumstances, the solvent extraction plant can remove the oil in an economical way. The basic technological steps used in today’s modern and highly efficient oil mills comprises the following steps:The first step of the cleaning is the removal of the tramp metal by means of a rotary type magnet separator.The next step in the process is the size reduction of the seed.

Edible Oil Extraction: The edible extraction  process consists of "washing"  the oil from the soybean flakes with hexane solvent in a countercurrent extractor.   Then the solvent is evaporated (i. e., desolventized) from both the solvent/oil  mixture (micella)  and the solvent-laden, defatted flakes (see Figure 9.11.1-3).   The oil is desolventized by exposing  the solvent/oil  mixture to steam (contact and noncontact).  Then the solvent is condensed, separated  from the steam condensate, and reused.  Residual  hexane not condensed  is removed  with mineral oil scrubbers. The desolventized oil, called "crude" soybean  oil, is stored for further processing  or loadout.

Edible Oil Refining: Crude vegetable  oils contain small amounts  of naturally occurring  materials  such as proteinaceous material,  free fatty acids, and phosphatides.  Phosphatides are removed  for lecithin recovery  or to prepare the crude oil for export.