Four common extraction processes for plant extracts

1. Steam distillation method

This method has the advantages of easy equipment acquisition and easy separation of the obtained components from water. However, during the process of extracting active ingredients, thermally unstable components such as polysaccharides are easily destroyed, and volatile oil is prone to undergo hydration reaction with water, leading to odor change.

2. Ultrasonic assisted method

This method has low extraction temperature and energy consumption, making it suitable for the extraction of polar and thermally unstable components. However, the existing ultrasound instrument capacity cannot achieve industrial production.

3. Supercritical CO2 extraction method

This method can effectively prevent the oxidation and escape of thermosensitive substances. In addition, since there is no solvent residue, the extracted raw materials can be used as feed or continue to extract other components. However, this method may result in missing physical property data due to high pressure, high investment costs, and high safety requirements.

4. Enzymatic hydrolysis

This method has the mildest extraction conditions and is a low-temperature extraction method with extremely fast reaction speed. Impurities are easily removed. However, this method has high cost, high equipment and technical requirements, and great limitations. A method that mainly utilizes cellulase, pectinase, protease, etc. (mainly cellulase) to destroy the cell wall of plants, in order to promote the maximum dissolution and separation of plant active ingredients. In the extraction process of enzyme extraction, the selection of enzymes, enzyme concentration, pH value, hydrolysis temperature, and hydrolysis time all affect the extraction rate of plant extracts.