What Should You Know About Pressing vs. Extraction in Edible Oil Manufacturing

Edible oil processing techniques can be divided into two main methods: pressing and extraction. The pressing method can be further classified into two types: cold pressing and hot pressing.

In the market, edible oil produced using the "pressing method" has increasingly become synonymous with "high-quality edible oil," favored by more and more consumers due to its superior quality and richer nutritional content. But do consumers truly understand the impact of different edible oil processing techniques on oil quality? Below is an analysis of edible oil processing techniques by oil equipment manufacturers.

Edible Oil Processing Techniques: Pressing Method and Extraction Method

Currently, China's edible oil market primarily employs two oil production techniques: the extraction method and the pressing method.

The pressing method relies on physical pressure to separate oil directly from oil-bearing materials. The entire process involves minimal chemical additives, ensuring the safety, hygiene, and purity of the edible oil while preserving its natural nutrients.

The extraction method uses a solvent oil to thoroughly soak the oil-bearing materials, followed by high-temperature extraction. The oil then undergoes refining processes such as degumming, deacidification, decolorization, and deodorization. The most notable feature of the extraction method is its high oil yield and low production cost. However, the high-temperature refining process diminishes the natural flavor of the vegetable oil, destroys fat-soluble vitamins, and may leave trace residues of the solvent oil.

Pressing Method: Cold Pressing and Hot Pressing

The pressing method in edible oil processing can be further divided into cold pressing and hot pressing.

Currently, most of the vegetable oils consumed in our daily lives are "hot-pressed oils" (pressed at temperatures above 120°C). This means the oil-bearing materials are cleaned, crushed, and subjected to high-temperature treatment before pressing. The hot-pressing process results in a lower residual oil content and a higher oil yield. However, the series of steps involving cleaning and high-temperature pressing can easily damage the natural nutrients of the oil-bearing materials. The oxidation value increases, leading to quality deterioration, which necessitates the addition of synthetic antioxidants to prevent spoilage. In terms of aroma, hot-pressed oils are notably fragrant, and in color, they tend to be darker.