Jasmine, a general term for evergreen shrubs or vines of the genus Jasminum, is native to India and Pakistan, and was introduced to China during the Han Dynasty and widely cultivated. Its leaves are emerald green, the flowers are white, and the aroma is strong. Jasmine has good health and beauty benefits.
At present, the extraction methods of jasmine essential oil mainly include simultaneous distillation extraction, adsorption method, leaching method, carbon dioxide supercritical extraction method and subcritical low-temperature extraction method. The distillation extraction method is to distill the fraction of the sample by steam and extract the essential oil with a solvent, which has a high extraction rate for trace components. The disadvantage is that the operating temperature is high, the time is long, and the aroma of the obtained essential oil is distorted, so it is less used; Carbon dioxide supercritical extraction is a low-temperature extraction and separation technology, but the process requires high pressure, high equipment manufacturing requirements, large equipment investment, and high product cost, so the application of this technology in essential oil extraction is restricted. The adsorption method mainly uses activated carbon to adsorb the aroma released by jasmine, and then uses carbon dioxide supercritical equipment to extract and adsorb saturated activated carbon to obtain jasmine essential oil. The leaching method mainly used hexane to extract jasmine, and the yield of extract was 022％～0.28, wherein the net oil content is more than 60, is the method that is widely used at present, but the shortcomings of this method are obvious, in order to retain the aroma of essential oil, a large amount of solvent needs to be consumed, and the extract obtained by extraction needs to further add ethanol for secondary separation in order to remove the solvent, and the operation is complicated. Hexane and ethanol were extracted twice, and the solvent was removed by heating twice, resulting in the volatilization loss of essential oils and the taste change of heating.
The subcritical low-temperature extraction technology can extract the active ingredients in plant essential oils, and has many advantages, such as high yield, low consumption, good aroma, complete composition, small investment, large scale, simple operation and the flower residue after extracting essential oil (extract) still has great utilization value. In addition, by further processing the extract, a pure oil that is liquid at room temperature can be obtained, which can be completely dissolved in perfumes, so it is also widely used in the field of flavor manufacturing.
Subcritical low-temperature extraction technology can be used to extract various plant essential oils, such as rose essential oil, jasmine essential oil, lavender essential oil, etc. Compared with traditional extraction methods, the subcritical low-temperature extraction technology has higher extraction efficiency and better aroma retention. At the same time, due to its use of low temperature and low pressure conditions, the active ingredients and nutrients in the plant can be better protected.
In addition to the application in the extraction of plant essential oils, subcritical low-temperature extraction technology can also be used in other fields, such as Chinese herbal medicine extraction, food processing, cosmetics manufacturing, etc. It can extract the active ingredients in Chinese herbal medicine, such as ginsenosides, flavonoids, etc.; In food processing, it can be used to extract vegetable oils, spices, etc.; In cosmetics manufacturing, it can be used to extract plant essences, antioxidants, etc.
In conclusion, subcritical low-temperature extraction technology is a new technology with a wide range of application prospects. With the increasing attention to health and environmental protection, it is believed that the application prospect of subcritical low-temperature extraction technology will be broader.