Extraction technology and production process of soybean extract.

1. Introduction

Soybean extract has gained significant attention in various industries due to its multiple functions. It is rich in bioactive compounds such as isoflavones, saponins, and proteins, which contribute to its health - promoting and functional properties. The extraction technology and production process play crucial roles in obtaining high - quality soybean extract. This article will discuss in detail the different extraction technologies and the overall production process of soybean extract.

2. Extraction Technologies

2.1 Microwave - Assisted Extraction

Microwave - assisted extraction (MAE) is an innovative extraction method that has emerged in recent years. It utilizes microwave energy to accelerate the extraction process.

The principle behind MAE is that microwaves can interact with the molecules in the soybean matrix. The polar molecules in the soybean, such as water and some bioactive compounds, will absorb microwave energy. This absorption leads to a rapid increase in temperature, which in turn enhances the mass transfer of the target compounds from the soybean matrix to the extraction solvent.

One of the major advantages of MAE is the significant reduction in extraction time. Compared to traditional extraction methods, MAE can complete the extraction process in a much shorter time. For example, in the extraction of isoflavones from soybeans, traditional methods may take several hours, while MAE can achieve similar extraction yields in just a few minutes to tens of minutes.

Moreover, MAE also improves the extraction efficiency. The rapid heating and mass transfer process can ensure that more target compounds are extracted from the soybeans. This is beneficial for obtaining a high - quality soybean extract with a high concentration of bioactive compounds.

2.2 Ultrasonic - Assisted Extraction

Ultrasonic - assisted extraction (UAE) is another effective extraction technology for soybean extract. UAE utilizes ultrasonic waves to enhance the extraction process.

When ultrasonic waves are applied to the soybean - solvent system, they create cavitation bubbles in the solvent. These cavitation bubbles grow and then collapse violently. The collapse of the cavitation bubbles generates high - pressure and high - temperature micro - environments locally. These extreme conditions can break the cell walls of soybeans, which helps to release the bioactive compounds trapped inside the cells.

UAE can also improve the mass transfer between the soybeans and the extraction solvent. The ultrasonic waves can cause agitation and turbulence in the solvent, which promotes the diffusion of the target compounds from the soybean matrix to the solvent. As a result, the extraction yield of bioactive compounds such as isoflavones and saponins can be significantly increased.

Compared to traditional extraction methods, UAE is relatively simple and cost - effective. It does not require complex equipment and can be easily integrated into existing extraction processes.

3. Production Process of Soybean Extract

3.1 Pretreatment of Soybeans

Before the extraction process, soybeans need to be pretreated. The first step is usually cleaning the soybeans to remove impurities such as dirt, stones, and damaged soybeans. This can be achieved by using sieves or washing with water.

After cleaning, the soybeans may be dehulled. Dehulling can improve the extraction efficiency as the hulls may contain substances that are difficult to extract or may interfere with the extraction of target compounds. Dehulling can be done mechanically using dehulling machines.

Then, the soybeans may be ground into a suitable particle size. Grinding can increase the surface area of soybeans, which is beneficial for the subsequent extraction process. The particle size should be carefully controlled to ensure optimal extraction results.

3.2 Extraction

Once the soybeans are pretreated, the extraction process can be carried out. Depending on the extraction technology chosen, such as MAE or UAE, the soybeans are mixed with an appropriate extraction solvent. Commonly used extraction solvents for soybean extract include ethanol, methanol, and water - ethanol mixtures.

The extraction process is carried out under specific conditions. For example, in MAE, the microwave power, extraction time, and solvent - to - sample ratio need to be optimized. In UAE, the ultrasonic power, frequency, and extraction time also need to be carefully controlled to achieve the best extraction results.

3.3 Separation

After the extraction, the next step is separation. Different separation methods are used to separate the extract from impurities.

• Filtration is a common separation method. It can remove large particles such as soybean residues from the extract. Filtration can be carried out using filter papers, filter membranes, or filter presses.
• Centrifugation is also widely used. Centrifugation can separate the extract from solid impurities by applying centrifugal force. High - speed centrifuges are often used to achieve efficient separation.

3.4 Concentration

After separation, the extract may need to be concentrated to increase the concentration of bioactive compounds. Concentration can be achieved by methods such as evaporation under reduced pressure. Evaporation under reduced pressure can remove the solvent from the extract while maintaining the bioactive compounds, thereby increasing the concentration of the extract.

3.5 Drying

The final step in the production process of soybean extract is drying. Drying is used to convert the liquid extract into a solid form for easier storage and transportation.

• Spray drying is a popular drying method. In spray drying, the liquid extract is sprayed into a hot drying chamber, where the solvent is rapidly evaporated, leaving behind solid particles of the soybean extract. Spray drying can produce fine - particle - sized soybean extract powder with good flowability.
• Freeze - drying is another option. Freeze - drying involves freezing the liquid extract first and then removing the ice by sublimation under vacuum. Freeze - dried soybean extract can better preserve the bioactive compounds and has a longer shelf - life.

4. Quality Control in the Production of Soybean Extract

Quality control is essential throughout the production process of soybean extract to ensure the final product meets the required standards.

4.1 Raw Material Quality

The quality of soybeans as the raw material is crucial. High - quality soybeans should be selected, free from contaminants such as pesticides, heavy metals, and mycotoxins. Regular inspection and testing of soybeans should be carried out to ensure their quality.

4.2 Extraction Process Monitoring

During the extraction process, parameters such as extraction time, temperature, and solvent - to - sample ratio need to be closely monitored. Deviations from the optimal conditions may affect the extraction yield and quality of the extract. For example, if the extraction time is too long or the temperature is too high, it may lead to the degradation of bioactive compounds.

4.3 Product Analysis

After the production of soybean extract, comprehensive product analysis should be carried out. This includes the determination of the content of bioactive compounds such as isoflavones and saponins, as well as the assessment of the physical and chemical properties of the extract, such as solubility, particle size, and moisture content.

5. Conclusion

The extraction technology and production process of soybean extract are complex and multi - faceted. Microwave - assisted extraction and ultrasonic - assisted extraction offer efficient ways to obtain high - quality soybean extract. The production process, including pretreatment, extraction, separation, concentration, and drying, needs to be carefully controlled to ensure the final product's quality. Quality control at each stage of the production process is also essential to produce a soybean extract that meets the high - quality requirements for various applications in the food, pharmaceutical, and cosmetic industries.

FAQ:

What are the main extraction technologies for soybean extract?

There are mainly microwave - assisted extraction and ultrasonic - assisted extraction. Microwave - assisted extraction uses microwave energy to speed up the extraction process, decreasing extraction time and enhancing extraction efficiency. Ultrasonic - assisted extraction takes advantage of ultrasonic waves to promote mass transfer and increase the extraction yield.

Why is separation technology important in the production process of soybean extract?

Separation technology is crucial in the production of soybean extract because it is used to separate the extract from impurities. This helps to ensure the purity and quality of the final soybean extract product.

What is the role of drying technology in the production of soybean extract?

The role of drying technology in the production of soybean extract is to convert the liquid extract into a solid form. This makes the soybean extract easier to store and transport.

How does microwave - assisted extraction improve the extraction of soybean extract?

Microwave - assisted extraction improves the extraction of soybean extract by using microwave energy. This energy accelerates the extraction process, which in turn reduces the extraction time and increases the extraction efficiency.

What are the advantages of ultrasonic - assisted extraction for soybean extract?

The advantages of ultrasonic - assisted extraction for soybean extract are that it utilizes ultrasonic waves to enhance mass transfer. This results in an improved extraction yield.

Related literature

• Optimization of Soybean Extract Production: A Review of Extraction and Separation Technologies"
• "Advanced Drying Techniques in the Production of Soybean Extract"
• "Microwave - Assisted Extraction of Bioactive Compounds from Soybean: A Comprehensive Study"
• "Ultrasonic - Assisted Extraction in Soybean Extract Manufacturing: Efficiency and Quality"