What is essential oil? Essential oil is an aromatic substance obtained from plants. The liquid extracted from flowers, leaves, seeds, skins, branches, barks, wood, roots, underground stems, gums or oily resins of plants has a special aromatic smell and complex and special chemical components. Just like Chinese herbal medicine, every plant or different parts of the same plant will have different smells, and the functions of plants are the same. The same part may have different smells and functions due to different extraction methods. Because the extracted substances have special physical or chemical functions, aromatic essential oils will have special functions, such as inhibiting bacteria, treating wounds, relaxing emotions, and invigorating spirits. Different names of aromatic essential oil, aromatic essential oil, plant essential oil, pure essential oils, essential oil, and types of essential oil products, such as aromatherapy oil, are common. Essential oil products on the market are divided into single essential oil, compound essential oil, vaporized essential oil, skin care products containing essential oil, edible essential oil and single essential oil (single oil) of traditional Chinese medicine, which refers to products without mixing more than two different single essential oils (except lavender essential oil). 2. Compound essential oil (compound oil or mixed essential oil) refers to a product made by mixing more than two different single essential oils (EX lavender essential oil+rose essential oil) or a product added with other special-purpose oils (EX lavender essential oil+jojoba oil for massage). 3. Isopropyl is an essential oil for evaporation. Alcohol (IPA for short) is mixed with essential oil, and then the aromatic molecular groups of essential oil dissolved in IPA are emitted by a heating device, and the smell of the place is improved by rapid diffusion. According to professional opinions and judgments, this commodity can only be called essence or environmental odor improvement product or deodorant, which has no effect on human body at all, let alone curative effect. Never use it as a general essential oil (directly smeared or smelled or used in a closed space) to avoid being affected by IPA. Because IPA is a flammable, explosive and highly volatile organic solvent, it will cause poisoning. Avoid using it in places with high temperature and fire source, so as not to cause fire or explosion. The way to obtain essential oil is 1. Steam distillation is extracted by boiling or cooking with water or boiling and precipitating in a pressure cooker. The extraction method of essential oil is obtained by complex procedures such as filtration. 2. Organic solvent extraction method. This extraction method is often used in the case that some components cannot be distilled by steam because of their high temperature resistance, because high temperature will destroy the activity of the extract or avoid high temperature, or the components that are not easy to deteriorate by steam distillation can be filtered and removed by organic solvents or other purification procedures to get the finished product. 3. The pressing method is not used for steam distillation or chemical solvent extraction. When applicable, the reasons may be high temperature, lack of suitable organic solvent, inability to remove suitable organic solvent and low yield, which is also the reason for using this method. Sesame, for example, can't be cooked with any solvent, but the cost is too high, it will smell, and it will lose its original characteristics and functions after being taken out. So the pressing method is the most effective and safest. The simplest method has to go through many subsequent processes to get the finished product. 4. Cold soaking or warm soaking, as the name implies, is to dissolve the substances in the extracted substances within an acceptable temperature range, and improve the dissolution speed and output by heating. 5.SCF supercritical fluid extraction supercritical fluid means that when the operating temperature and pressure exceed the critical point, the fluid has many unique physical and chemical properties. The low viscosity of gas and the chemical properties of liquid, such as high density, high diffusion coefficient, low surface tension and solubility that can change with temperature and pressure, can be said to be a "green" extraction method. The principle of supercritical fluid extraction can be said that the required components can be easily extracted by supercritical fluid, and there is no solvent residue, and the product is damaged by heat. The physical properties of supercritical fluid are between gas phase and liquid phase. The viscosity of fluid is close to gas, and the density is close to liquid 1. The higher the density, the more gaseous supercritical fluid can be transported. 2. The lower the viscosity, the lower the power required for transportation. The diffusion coefficient of supercritical fluid is 10~ 100 times higher than that of liquid, that is, the mass transfer resistance is much smaller than that of liquid, so the mass transfer is faster than that of liquid. Supercritical fluid has no surface like gas. Tension easily penetrates into porous tissues, and the chemical properties of supercritical extraction are different from those of gas and liquid. For example, carbon dioxide has no extraction ability in gas state, but when it enters supercritical state, carbon dioxide becomes organophilic, so it has the ability to dissolve organic matter, which will vary with pressure and temperature. What is the green environmental protection technology of supercritical carbon dioxide extraction? Traditional solvent extraction needs a lot of organic solvents, which takes a long time, seriously affects the environment and ecology, and costs money. Residual organic solvents in products are also very harmful to human health. Supercritical extraction technology can extract quickly without using organic solvent, and use the special properties of supercritical carbon dioxide to replace the traditional solvent extraction method to achieve the purpose of separation and purification, which can provide absolutely healthy and harmless products. This is the most common example of extracting caffeine from coffee beans with supercritical fluid CO2. However, when extracting perfume from flowers, CO2 is naturally gasified and separated at low pressure, so there will be no solvent pollution and poisoning. Several extraction methods are introduced in the above contents, each method has its own characteristics and considerations, and the most suitable extraction method will be selected because of the different conditions of plants. Manufacturers will extract the best products to supply consumers with this grade of essential oil. Generally speaking, essential oils are classified as ordinary drugs or chemicals, which can be roughly divided into industrial grade (T.G.), chemical grade (C.P.), first grade (E.P.) and super grade (G.R.). As for the evaluation grade, it is probably based on the following eight considerations (this standard is a reference for the classification of ordinary drugs or chemicals)/kloc- The source of raw materials supply must be able to provide reliable analysis and inspection data, and the quality of raw materials in different batches should also be consistent. 2.3. Consistency of color and taste of raw materials. 4. Provision of skin allergy test data. 5. Description of the stability of raw materials. 6. Description of interaction with other raw materials. 7. Matching elements of manufacturing industry. 8. Provision of price. As for essential oils, there will be grading conditions, such as origin, climate, heavy metals, pesticides and so on. Generally speaking, when choosing to buy essential oil, in addition to paying attention to the label on the package, you can also directly check the relevant government agencies online to see whether it is imported goods, imported packaging, import grade and so on. At present, essential oil has developed from simply improving air odor to multiple uses abroad, not only in the beauty industry, but also in medical institutions. Emotional control, etc. It is also used in psychiatric wards, hospice wards and general wards. There are a large number of research reports, papers and periodicals. Foreign countries are related to essential oils. Unfortunately, there are not many related research papers in Taiwan Province Province. There are few practical and in-depth research papers. It is not essential oil that has no research value. We just need to do more in-depth research on essential oils, which can't be done by one person or several people. Physicians and psychiatrists may be needed. Or other professional doctors, nurses, psychologists, social science researchers, human behavior researchers, chemists, physicists, microbiologists, artists, beauty salon researchers, etc. , including psychology, physiology, art, science, medicine, etc. It is really not easy to complete the function of aromatic essential oil-the soul of aromatherapy-the soul of aromatherapy-the function of plant essential oil. Living in the prosperous e era, we can be satisfied. We can also get together every night and hang around Xiangche Restaurant. This is how cities satisfy our vanity and realize our desires. However, the buildings like iron walls, the jungle of reinforced concrete, the mountains of official duties all day, the overwhelming mental pressure ..., the feeling of suffocation and dullness is coming all the time, and my mind is gradually numb, so I always hope to find a secluded place like a paradise, away from the hustle and bustle of the secular, put aside secular affairs and wash my mind. Aromatherapy, which exudes the fresh breath of nature, came into being in line with the modern fashion trend. As the soul of aromatherapy, natural plant essential oil has been recognized by the public for its unique curative effect, cleaning and sterilization effect and pleasant fragrance for more than 6 thousand years. Today, when we look back on the ancient civilizations of the past and pursue the balance of today's life, these characteristics are rediscovered. In today's society, people are faced with pressure, pollution, junk food and a fanatical lifestyle that lacks physical activity, which will have a negative impact on our body and mind. The art of herbal therapy lies in extracting the essence contained in the flowers and resins of aromatic plants, and restoring the balance between body and mind through the most important sense of smell and touch. Aromatic essential oil is known as "phytohormone". In fact, many essential oils are similar in nature to human hormones and play an important role in the human body. Aromatic essential oil acts on human body through the following ways: 1 molecule Aromatic essential oil stimulates olfactory nerve through nasal breathing, and olfactory nerve transmits the stimulation to the brain center, and the brain generates excitement. On the one hand, it dominates nerve activity and plays a role in regulating nerve activity; On the other hand, the secretion of glands is controlled by nerve regulation, thus regulating the whole internal environment of human body. Oral essential oil can enter human body through digestive tract, regulate blood circulation and lymphatic circulation, further regulate endocrine and improve internal environment. Through affinity, it directly enters the subcutaneous essential oil molecules. On the one hand, it stimulates nerves, and finally regulates nerve activity and internal environment; On the other hand, it directly changes the internal environment and other States, thus accelerating body fluid activities, thus improving the internal environment and further regulating the whole body and mind. Through affinity, we can quickly change the living environment of local tissues and cells, accelerate their metabolism, and completely solve some problems caused by local metabolic disorder. Essential oil molecules contain antibacterial and antiseptic components, which can effectively kill and reduce second-hand smoke, bacteria, microorganisms, suspended particles, dust mites and other pollutants, and help to create a healthy living environment. Essential oil molecules enter the human body, enhancing human immunity and helping to resist the attacks of various bacteria and viruses.