Plant oil, a precious gift from nature, plays a vital role in our daily lives as both a culinary essential and an indispensable industrial commodity. Yet, the original plant oil contains fats, proteins, impurities, water, pigments, and other components. To present the natural beauty in its purest and most refined form, plant oil must undergo a meticulously designed refining process, ultimately producing products that meet the highest standards. Let us embark on a journey to explore the secrets and techniques of refining plant oil, discovering the profound impact of the refining process on the oil's quality.

The Refining Process of Plant Oil

Dehydration

The original plant oil contains relatively high water content, which must be reduced through a dehydration process. Typically, the oil is heated and exposed to high temperatures to facilitate the evaporation of water.

Deacidification

Some plant oils contain free fatty acids that can diminish the quality and stability of the oil. During the deacidification process, alkaline substances such as sodium hydroxide react with the oil to neutralize the free fatty acids, forming soap, which is then separated from the oil through precipitation.

Decolorization

Natural plant oil may contain pigments, carotenoids, and other substances that impart undesirable colors. Decolorization involves adding adsorbents such as activated carbon to the oil, which absorb and remove impurities and pigments, resulting in a clear and transparent appearance.

Deodorization

Certain volatile compounds, such as free fatty acids, ketones, and aldehydes, contribute to unpleasant odors in plant oil. Deodorization involves heating the oil and using steam distillation to remove these volatile compounds, resulting in a mild and appealing aroma.

Desilication

Some plant oils may contain trace amounts of silicates, which can affect the oil's stability and quality. Desilication entails adding acidic substances, such as acid clay or acidified clay, to react with the oil and remove the silicates.

Dewaxing

At low temperatures, certain plant oils crystallize to form waxes, influencing their transparency and flowability. Dewaxing involves cooling and filtering the oil to remove the waxy substances, allowing the oil to remain in a liquid state.

The Final Products

Following this series of refining steps, the original plant oil is transformed into high-quality edible or industrial oils. Refined plant oil typically exhibits reduced levels of free fatty acids, a transparent color, a mild aroma, and excellent stability and flowability, making it suitable for various applications.