Extraction methods and functions of plant extracts
The chemical dictionary tells you the extraction methods and functions of plant extracts. Plant extracts refer to substances extracted or processed from plants (all or a part of plants) using appropriate solvents or methods. They can be used in the pharmaceutical industry, food industry, health industry, beauty industry and other industries.
Extraction method of plant extract
Solvent extraction
The solvent extraction method uses a solvent to extract the effective ingredients from the solid raw material, and the solvent used must have the characteristics of mutual solubility with the extracted solute. After the plant material is crushed, it is put into a suitable container, and several times the amount of solvent is added. The extraction can be carried out by dipping, percolating, decocting, refluxing and continuous extraction.
In the extraction process of the solvent extraction method, the concentration of the solvent, the ratio of material to liquid, the extraction temperature, and the extraction time will directly affect the extraction rate of the effective ingredients. Cristina Juan et al. used solvent extraction to extract ochratoxin A from rice, and used fluorescence detection and liquid chromatography to determine the content of OTA. The study showed that under the conditions of the most suitable material-to-liquid ratio, extraction temperature and extraction time , The highest OTA content of the extract is 4.17ng/g. Monte D. Holt et al. used solvent extraction to extract alkylresorcinol from raw and cooked wheat seeds. Experiments show that solvent extraction can save extraction time.
Ultrasonic extraction
Ultrasonic extraction uses the strong vibration and cavitation effect produced by ultrasonic waves to accelerate the release, diffusion and dissolution of substances in plant cells into the solvent, while keeping 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. For most components, the ultrasonic extraction method can greatly shorten the extraction time compared with the conventional solvent extraction, consumes less solvent, and has a higher leaching rate, so it has a higher extraction efficiency.
In the ultrasonic extraction process, the selection and concentration of the solvent, the ratio of material to liquid, the extraction temperature, and the extraction time will directly affect the extraction rate. Ling Zhou et al. used ultrasonic extraction to extract schisandra and mainly studied the factors affecting the ultrasonic extraction rate. The experimental study concluded that the extraction rate increased with the increase of temperature and increased with the increase of power. Hong Van Le et al. used ultrasound to extract vitamin E and phenolic compounds from cherries. They mainly compared the differences in extraction time and extraction rate between ultrasonic extraction and enzyme extraction. The experimental results showed that ultrasonic extraction was shorter than enzyme extraction. 6 times, the extraction rate of ultrasonic extraction is 2 to 3 times that of enzyme extraction. Zhong Aiguo et al. used the method of ultrasonic extraction of chlorophyll from fresh bamboo leaves and used a spectrophotometer to quantitatively determine the content of the extracted chlorophyll. The results show that: compared with the commonly used organic solvent extraction method, the ultrasonic extraction method not only has high extraction rate, fast speed, and high efficiency, but also extracts at room temperature without heating and saves energy.
