All volatile oils, oils, extracts, liquid extracts, dry extracts, active ingredients, and effective parts obtained from plants, animals, and minerals for preparation production through certain extraction methods are all extracts.
1. Effective part: it refers to an extract composed of one or several types of components extracted from a single plant, animal, mineral, etc., of which the content of components with a clear structure should account for more than 50% of the extract.
2. Active wholesale plant extract: natural single ingredients extracted from plants, animals, minerals, and other substances, the content of single ingredients should account for more than 90% of the total extract.
The components of Chinese herbal extracts can generally be divided into glycosides, acids, polyphenols, polysaccharides, terpenes, flavonoids, alkaloids, etc., such as green tea extract, whose main component is tea polyphenols, ginseng extract mainly contains many ginseng monomer saponins. Types of herbal extracts can be divided into an extract, powder, lens, etc., according to different properties, such as violet leaf extract, hangbai chrysanthemum extract.
1. Water extraction
Good water solubility. Polysaccharides, organic acids, saponins, phenols, tannins, amino acids, polypeptides, proteins.
2. Organic solvent extraction
Ethanol extraction: phenols, tannins, organic acids, coumarin, cardiac glycosides, steroids.
5% HCl-ethanol extract: alkaloid.
Petroleum ethers: steroids, terpenes, fatty oils.
3. Enzymatic hydrolysis
Starch, pectin, protein and other impurities, mild reaction, cellulase.
4. Ultrasonic extraction
Definition: Ultrasonic cavitation to accelerate the leaching of plant active ingredients.
Advantages: short herb extraction time, simple extraction method, high extraction rate, low extraction temperature, and avoiding high temperature and high-pressure damage to active ingredients.
Disadvantages: high container requirements, noise, equipment amplification problems.
5. Microwave extraction
Definition: In the microwave field, there are differences in the ability of substances to absorb microwaves, and some components can be selectively heated and extracted.
The extraction time is short, the equipment is simple, and the investment is less. The extraction mechanism is unknown.
6. Supercritical extraction
Use supercritical fluid instead of conventional organic solvents for extraction and separation, volatile components, fat-soluble substances, highly heat-sensitive substances and valuable medicinal materials, low temperature, retains active ingredients, no solvent residue, high purity, and simple operation, high-pressure equipment, disposable large investment, and high operating cost.
7. Membrane separation
Definition: the separation of substances according to their molecular weight.
(1) Water treatment
Removal of suspended solids, colloids, and microorganisms in water, sewage treatment, removal of urban sewage viruses, seawater, and brackish water desalination, pure water, and ultrapure water preparation.
(2) Chinese herbal extraction
Making extracts from herbs, removing polymer impurities, and improving the clarity of medicinal liquids.
Tea polyphenols and instant tea powder, fruit juice separation, and concentration, beer recovery of beer residue, white beer sterilization, recovery of whey protein.
(4) Production of enzyme preparations