Oil refining can remove impurities and undesirable ingredients in oils and fats, and can improve the stability and quality of oils and fats. Oil refining is an important part of edible oil processing. Oil refining methods are mainly divided into: physical refining and chemical refining. We can choose physical refining or chemical refining based on factors such as raw material characteristics, product requirements, cost considerations, and environmental protection requirements. Choosing the right refining method is crucial to ensuring the quality and safety of oil products.
The physical refining edible oil process is a production process that removes impurities and undesirable components from edible oil by physical methods, aiming to improve the quality and taste of edible oil and meet the modern people’s demand for healthy food. The following is a detailed introduction to the process:
I. Main steps of physical oil refining
1. Removal of impurities
a. Common impurities in edible oil include suspended matter, impurity precipitates and colloids.
b. Through physical methods such as precipitation, filtration and centrifugation, these impurities can be effectively removed to make the edible oil purer.
2. Deacidification
a. Acid value is an important indicator for measuring the quality of edible oil. High acid value will reduce the quality and stability of edible oil.
b. Deacidification is mainly achieved through two steps: alkali refining and steam deacidification:
Alkali refining: Use alkaline solution to neutralize free fatty acids in edible oil to reduce acid value.
Steam deacidification: Use high temperature and high pressure steam to act on free fatty acids in edible oil to volatilize them and achieve the purpose of reducing acid value.
3. Deodorization
a. There are often some odor substances in edible oil that are difficult to remove. These odor substances will affect the taste and quality of edible oil.
b. Deodorization is mainly achieved through two steps: distillation and steam deodorization:
Distillation: Heat the edible oil to a certain temperature to evaporate the odorous substances, and then condense them through a condenser to obtain odorless edible oil.
Steam deodorization: Use high-temperature and high-pressure steam to act on the odorous substances in the edible oil to evaporate them and achieve the deodorization effect.
Ⅱ. Main features of physical oil refining
1. Environmental protection and economy
The physical refining edible oil process does not use chemical agents, does not produce wastewater and waste gas, and reduces pollution to the environment.
2. Retain nutrients
Since no chemical agents are used, the nutritional components of the edible oil will not be destroyed, and its original nutritional value is maintained.
3. Simple operation
The process of physical refining edible oil is simple and easy, with low operating costs and suitable for large-scale production.
4. Excellent oil quality
The deacidification tower can directly remove free fatty acids, significantly reducing the loss of neutral oil, which can generally be as low as 1.05%~1.1% (mass).
Good flavor, suitable for oils with low colloid content, such as olive oil, palm oil, peanut oil and sunflower oil.
III. Deficiencies and improvements of physical oil refining
1. Unable to completely remove trace impurities
The physical refining edible oil process cannot completely remove trace impurities and harmful substances in edible oil, such as heavy metal ions and pesticide residues.
2. Loss of nutrients
Due to the high temperature treatment required in the process, some nutrients in the edible oil may be lost.
The oil yield may be low
In some cases, the oil yield of physical refining may not be as high as that of chemical refining, which will affect the yield and economic benefits.
3. Time and efficiency
The physical refining process may be relatively long and require more time and operation steps.
In view of the above deficiencies, in actual production, it is necessary to select appropriate processes according to different needs and requirements, and continuously optimize and improve the physical refining edible oil process to improve the oil yield, reduce the loss of nutrients, and better remove impurities and harmful substances in edible oil.
In summary, the physical refining edible oil process has significant advantages in improving the quality and taste of edible oil, and it also meets the modern people’s pursuit of healthy food. However, this process also has some shortcomings, which need to be paid attention to and improved in actual production.