In modern edible oil plant, crude oil is only the starting point-it contains phospholipids, free fatty acids, pigments, odor substances and trace impurities, and cannot be directly listed as commercial oil. Refining is to directionally remove these “by-products” through a series of physical-chemical unit operations, and obtain refined oil that meets the national standard, is clear and stable, and has high smoke point.

Where does the crude oil come from?

The sources of crude oil mainly include plants and animals. Vegetable oil is usually extracted from soybean, rapeseed, peanut, palm fruit and other raw materials by pressing or leaching, while animal oil comes from adipose tissue of pigs, cattle, fish and other animals. Regardless of the source, crude oil needs to be refined to meet the quality requirements of edible or industrial use.

The core of refining

The core steps of crude oil refining include the following stages:

1. Degumming: removing phospholipids and other colloidal substances from crude oil through hydration or acidification. This step can significantly improve the transparency and stability of oil.

2. Deacidification: removing free fatty acids by alkali refining or physical refining, reducing acid value, improving the taste of oil and prolonging the shelf life.

3. Decolorization: the pigment in crude oil is adsorbed by activated clay or activated carbon to make the oil clearer and more beautiful.

4. Deodorization: the odor substances in crude oil are removed by high-temperature steam distillation, giving the refined oil a fresh and natural aroma.

5. dewaxing (optional): for some vegetable oils (such as sunflower seed oil), wax needs to be further removed to avoid turbidity at low temperature.

Modern trend: moderate refining

In recent years, with the popularization of the concept of healthy eating, moderate refining has gradually become an industry trend. Although the traditional refining process can significantly improve the purity of oil, it may also lead to the loss of some nutrients, such as vitamin E and phytosterol. Moderate refining, on the other hand, removes harmful impurities and tries to keep natural ingredients beneficial to human body. This technology not only improves the nutritional value of the product, but also wins the favor of consumers for healthy food.

In a word, the transformation from crude oil to refined oil is a complex and delicate process in oil mill plant. With the continuous progress of technology, the oil processing industry will continue to seek a higher level of development in terms of safety, nutrition and sustainability, and provide consumers with better edible oil products.