What is physical refining of edible oil?

Physical refining of edible oil is also called steam distillation deacidification, which is according to the characteristics of volatile difference between triglycerides and free fatty acids (under vacuum condition), in high vacuum (0.6 kPa) atmospheric pressure and high temperature (240 ~ 260 ℃) to remove free fatty acids and other volatile substances from oil by water vapor distillation.

The boiling point of different fatty acids under different conditions:

Fatty acid No water vapor (atmospheric pressure) Fatty acid : water vapor
Atmospheric pressure (1 : 2.5) 20kPa (1 : 1)
Lauric acid 301 191 167
myristic acid 330 211 173
palmitic acid 340-356 224 211
stearic acid 360-383 243 223
oleic acid -- 239 220

Physical refining of edible oil is particularly suitable for low-gum tropical oil seeds, such as palm and coconut, etc, and for refining animal fats.

In edible oil physical refining process, steam distillation can not only remove acid, but also can achieve removing solvent in leaching oil, deodorized, detoxified (organochlorine in rice bran oil and some cyclic hydrocarbons and other toxic substances) and partially decolorized.

physical refining of edible oilEdible oil physical refining process

The crude oil quality requirements before physical deacidification:

The quality of crude edible oil and its pretreatment quality are the preconditions of physical refining of edible oil. Non-hydrophilic phospholipids in crude edible oil are mostly carriers of metal ions such as calcium, magnesium and iron, which can lead to a deeper color, less transparency, lower flavor and stability, and even make the deacidification and deodorization process fail. Therefore, in the edible oil physical refining process, the crude edible oil must be pretreated degumming and decoloring.

The key point of physical refining of edible oil:

1. Steam distillation deacidification(continuous)

Temperature: 250~270℃

Pressure: 0.25~0.40kPa(2-3mmHg)

Time: 80-100min

The direct steam consumption: 1%-4%G0; (0.1-0.2MPa)

2. Cooling and filter


The characteristics of physical refining of edible oil:

1. Less consumption of auxiliary materials, no sewage;

2. Simple process, less equipment, low operating cost;

3. High refining rate;

4. Fined edible oil is of high quality;

5. Physical refining of edible oil has some limitations;

6. After physical refining of edible oil, if the oil color is deep, it is difficult to remove.

Physical refining of edible oil and chemical refining of edible oil both have their own advantages. Henan Doing Company is a professional manufacturer of edible oil refinery machine. If you have any question, our engineer will explain to you. Welcome to write down your message!

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