Rubber seed has high oil content around 40-50% w / w. Rubber seed oil contains unsaturated fatty acids that can be used as raw material for making margarine.

The flow diagram of the process of making margarine:
Rubber seed oil -->Neutralization process --> bleaching process --> hydrogenation process --> process Deodorization --> emulsification process  --> margarine

The manufacturing process of margarine includes six stages: 

1. Neutralization 

Fat would be flammable, if there is lot of free acid. This is because since the critical parameters of temperature (smoke point, flash point & fire point) lower. Therefore, the fat needs to be purified with the neutralization process.
  • Smoke point: the temperature where the first occurrence of thin bluish smoke when heated fat.
  • Flash point: the temperature where the fat starts to burn when the heating continued.
  • Fire point: temperature where the fat burned steadily.
Neutralization is the process of separation of free fatty acids from oils or fats by reacting the free fatty acid with a base or other reagents to form soap (soap stock). Neutralization in the scale industry generally use NaOH because it is more efficient and cheaper than any other neutralization.

The reaction between free fatty acid with NaOH is as follows:
                       R-COOH + NaOH ---------> RCOONa + H2O

Excellence neutralization using NaOH:
• reduce the dye and dirt in the oil
• be able to remove phosphatides, proteins, resins and suspension in the oil that cannot be removed by gum separation processes.

The more dilute solution of NaOH used, the smaller neutralized but will more likely the loss of oil because the oil with soap to form an emulsion. Generally, free fatty acids containing a lower concentration used 0.15 N. NaOH.

Soap is formed in this reaction can help the separation of impurities such as dyes and phospholida and proteins by forming an emulsion. Penetration will also neutralized a small amount of neutral oil (trigleserida, monogleserida, diglycerides and triglycerides). By centrifugation, soap or emulsion formed can be separated from the oil.

2. Bleaching 

Bleaching is the process of removing dye that is not preferred in the oil. Bleaching done by mixing the oil with a small amount of adsorbent, such as bleaching earth and activated carbon. The dye in the oil will be absorbed by the adsorbent surface and also absorb colloidal suspensions (gums and resins) and the results of degradation of oils such as peroxide.

3. Hydrogenation 

Hydrogenation process aims to saturate the double bond carbon from fatty acids chain in oils or fats. Hydrogenation process using pure hydrogen and nickel powder is added as a catalyst, thus making the fat more plastic.

Mechanism of hydrogenation process:
                 H2 + R – CH = CH – CH2 – COOHR ----------> CH2 –CH2 – CH2 – CHOOH
This hydrogenation reaction occurs on the catalyst surface resulting in a reaction between molecules of the oil with hydrogen gas. Nickel is a frequently used catalyst in the hydrogenation process than the other catalysts (palladium, platinum, copper chromite). This is because nickel is more economical and more efficient than other metals. Nickel also contains small amounts of Al and Cu which serves as a promoter in the process of oil hydrogenation.

Fat Hydrogenation is selective, the fat with a higher degree of unsaturation would be more easily hydrogenated.

4. Deodorization 

Deodorization process is fat/oil refining process that aims to eliminate odors and bad taste in the oil. Deodorization process carried out with the oil by steam distillation in atmospheric pressure or a vacuum.

Deodorization process conducted in a closed vertical steel tube:
  • pump oil into the Deodorization kettle.
  • oil then heated at a temperature of 210o C at atmospheric pressure and then at low pressure (below 1 kPa)
  • flow steam for 1-2 hours to transport a compound that can evaporate.
  • The pressure drop during the deodorization process will reduce the amount of steam that will be used and prevents hydrolysis of oil by water vapor. In Deodorization tank (D-240) works at a temperature of 210 ° C and pressure of 0.03 atm. 
5. Emulsification
Emulsification process is process adding oil emulsifier and oil phase liquid phase at a temperature of 80o C with a pressure of 1 atm.

a. The process of mixing emulsifier in the oil phase
Oil emulsifier phase is additional material that can dissolve in oil that is useful to avoid the separation of water from oil-water emulsion, especially in storage. This emulsifier example : Lechitin while adding B-carotene in margarine as dyes and vitamins A and D to add nutrition.

b. The process of mixing emulsifier in liquid phase
Emulsifier liquid phase is an additional ingredient which is insoluble in oil. These additional ingredients mixed into the water that will be used to make emulsions with oil. Emulsifier liquid phase are:
  • salt to taste salty
  • TBHQ (antioxidant) prevents oil oxidation that resulted in damaged and rancid oil
  • Sodium Benzoate as a preservative. 
6. Packaging 

Once the emulsification stage finished, then proceed to the packaging process.

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