Common extraction methods for plant extracts-公司动态-植物提取物|植物精油|果蔬粉-山东春来生物医药科技有限公司

Plant extracts are the carrier of modern plant medicine science and technology, and are the main raw materials for plant pharmaceutical preparations. The commonly used methods for extracting plant extracts include solvent extraction, ultrasonic extraction, microwave extraction, and enzyme extraction. Supercritical fluid extraction and microwave assisted extraction are widely used as new extraction techniques.

1、 Solvent extraction method

Solvent extraction method uses solvents to extract effective ingredients from solid raw materials, and the solvents used must be compatible with the extracted solute. After crushing the plant material, place it in a suitable container, add several solvents, and extract it through methods such as impregnation, percolation, boiling, reflux, and continuous extraction. During the solvent extraction process, solvent concentration, solid-liquid ratio, extraction temperature, and extraction time all directly affect the extraction rate of active ingredients.

2、 Ultrasonic extraction method

Ultrasonic extraction utilizes the strong vibration and photochemical effects generated by ultrasound (cavitation effect refers to the dynamic process of growth and collapse of micro gas nucleus cavitation bubbles existing in liquids under the action of sound waves, which occur when the sound pressure reaches a certain value) to accelerate the release, diffusion, and dissolution of substances in plant cells into solvents, while maintaining the structure and biological activity of the extracted substances unchanged. The principle of ultrasonic extraction is mainly a physical process, and it is a relatively new extraction method that has gradually received attention in recent years. Compared with conventional solvent extraction methods, ultrasonic extraction method can greatly shorten extraction time, consume less solvent, have high leaching rate, and have higher extraction efficiency.

During the ultrasonic extraction process, the selection and concentration of solvents, solid-liquid ratio, extraction temperature, and extraction time all directly affect thextraction rate.

3、 Microwave assisted extraction

Microwave assisted extraction is a new technology that utilizes microwave energy to improve extraction efficiency. Microwave assisted extraction is a method of selectively extracting target components from materials using the characteristics of microwave heating. By adjusting microwave parameters, the target components can be effectively heated, which is beneficial for the extraction and separation of the target components. The principle of microwave assisted extraction of plants is that plant samples absorb a large amount of energy in the microwave field, while the surrounding solvents absorb less, resulting in thermal stress within the cells. Plant cells are broken due to thermal stress generated within the cells, causing substances inside the cells to come into direct contact with relatively cold extraction solvents, thereby accelerating the transfer of target products from the cells to the extraction solvent, thereby enhancing the extraction process. In principle, microwave assisted extraction also uses thermal energy such as soaking and filtering, but the speed of extracting plant extracts is much faster than traditional methods, which can reduce extraction time and avoid the destruction and degradation of valuable plant extracts.

At present, microwave assisted extraction has become a powerful tool for extracting active ingredients from natural plants due to its fast extraction speed and good extraction quality. But microwave assisted extraction is selective internal heating, which requires the processed material to have good water absorption. In other words, the separated product should be located in a position that is easy to absorb water, otherwise it is difficult for cells to absorb enough microwave and break down on their own, and the product is difficult to release quickly. For liquid extraction systems, the solvent is required to be polar, while non polar solvents are not sensitive to microwaves.