What are the main steps in the peanut oil refining process?

Peanut oil, as a high-quality edible oil, is widely favored by consumers for its rich nutritional value and unique flavor. However, during the pressing process, peanut oil may contain various impurities and harmful substances, such as aflatoxin and free fatty acids, which affect its quality and stability. Therefore, to provide safer and healthier peanut oil, refining processes are necessary to purify the oil and improve its quality. So, what are the processes and main steps involved in peanut oil refining?

Methods of Peanut Oil Refining

Peanut oil refining primarily includes physical refining and chemical refining methods, which can be selected based on different requirements.

Physical Refining

Physical refining involves removing impurities and harmful substances from peanut oil through physical means. The main methods include:

(1) Filtration: Removing large particles of impurities and oil residues from peanut oil using filters.

(2) Sedimentation: Utilizing the density difference between impurities and oil, allowing impurities to settle at the bottom through standing, thereby separating water and fine impurities.

(3) Adsorption: Using adsorbents to separate impurities and harmful substances from the oil.

Chemical Refining

Chemical refining involves the use of chemical reagents to assist in purification on the basis of physical refining. The main methods include:

(1) Alkali Refining: Using alkali to neutralize free fatty acids and remove rancid substances from the oil.

(2) Decolorization: Using decolorizing agents such as activated carbon to adsorb pigments in the oil, lightening its color.

(3) Deodorization: Removing volatile substances from the oil through high temperature and high vacuum conditions, enhancing the oil's aroma and stability.

Peanut Oil Refining Process

The peanut oil refining process includes the following main steps:

Pre-treatment: 

Screening, cleaning, and processing peanut raw materials to ensure cleanliness and consistency.

Pressing: 

Pressing the pre-treated peanut raw materials to obtain crude peanut oil.

 

Separation: 

Removing phospholipids, proteins, and other impurities from crude oil.

Physical Refining:

Applying physical refining methods to the separated peanut oil, including filtration, sedimentation, and adsorption, to remove impurities and harmful substances.

Chemical Refining:

 If necessary, performing chemical refining on the physically refined peanut oil, including steps such as alkali refining, decolorization, and deodorization.

Quality Testing: 

Conducting quality tests on the refined peanut oil to ensure it meets national food safety standards.

Storage and Transportation: 

Storing the refined peanut oil and transporting it to its destination for sale and use.

During the peanut oil refining process, quality control is a key factor in ensuring the final product's quality, including the following aspects:

Raw Material Control: Selecting high-quality peanut raw materials that meet production requirements, ensuring the absence of harmful substances such as aflatoxin.

Process Parameter Control: Precisely controlling various process parameters, such as temperature, pressure, and time, to ensure refining effectiveness and product quality.

Chemical Reagent Control: Strictly managing the types, quantities, and usage times of chemical reagents to ensure the safety and effectiveness of the chemical refining process.

Quality Testing: Employing various testing methods to evaluate the peanut oil's quality, including physicochemical indicators, nutritional components, odor, and taste, ensuring compliance with food safety standards.

Storage and Transportation Control: Cleaning and disinfecting containers used for storing refined peanut oil to prevent secondary contamination during storage and transportation. Additionally, ensuring temperature and humidity control during transportation to maintain the quality of the peanut oil.

As consumers' demand for high-quality and healthy food continues to grow, peanut oil refining technology will face more challenges and opportunities. In the future, peanut oil refining technology will further develop toward efficiency, environmental friendliness, and intelligence to meet market demands and food safety requirements. Meanwhile, with continuous advancements in technology and the emergence of new equipment, novel peanut oil refining technologies will be widely applied and developed. These new technologies and equipment will provide strong support for the development of the peanut oil industry, offering consumers safer and healthier peanut oil products.