Method for preparing essential oils

Abstract

The invention relates to a method for preparing essential oils. The method comprises the following steps: taking and smashing raw materials; placing the smashed raw materials in an extraction kettle; carrying out supercritical extraction by taking a supercritical carbon dioxide fluid as an extractive solvent and taking alcohol with the volume concentration of 55 to 65 percent as an entrainer, wherein the extraction temperature is 25 to 38 DEG C, the extraction pressure is 15 to 22 MPa, the extraction time is 1.5 to 3 h, the ratio between the quality (Kg) of the raw materials and the volume (L) of the extraction kettle is 0.2 to 0.5 : 1, and the ratio between dose (L) of the entrainer and the volume (L) of the extraction kettle is 0.05 to 0.07 : 1; separating with a separation kettle to obtain an extract; placing the extract obtained through extraction in a molecular still; carrying out molecular distillation under the conditions of 0.3 to 0.5 Pa, 160 to 180 DEG C; and collecting to obtain a corresponding essential oil. The method can be used for extracting essential oils from various plants, so that compared with the prior art, the invention has the advantages of high essential oil yield and high contents.

Description

technical field [0001] The present invention relates to a kind of method for preparing plant essential oil, specifically with supercritical CO 2 Technical extraction combines molecular distillation to prepare plant essential oils. Background technique [0002] Plant essential oil is a unique aromatic substance of plants, which is extracted from the flowers, leaves, roots, bark, fruits, seeds, resins, etc. of herbaceous plants by distillation and pressing. Plant essential oils are composed of more than one hundred components, and of course some are composed of hundreds to thousands of components. Generally speaking, plant essential oils contain alcohols, aldehydes, acids, phenols, acetones, and terpenes kind. Take rose essential oil as an example, 86% is composed of more than 300 components, and 14% is composed of many trace compounds. The composition ratio of these two parts is different, which will also affect the taste and curative effect. Bulgarian rose contains 33-55%...

AI Technical Summary

Problems solved by technology

[0006] In view of the complex composition of plant essential oils and the easy oxidation of polyunsaturated fatty acids in the extraction process, the current extraction methods of plant essential oils mostly use supercritical CO alone. 2 Extraction, the essential oil content that obtains is low, and yield is low, as the method for Chinese invention patent supercritical carbon dioxide extraction jasmine oil that publication number is CN1173531, the time is long, and the essential oil content that obtains is low

Another example is a Chinese invention patent with the publication number CN1380380, a kind of supercritical CO 2 The method of fluid extraction and purification of natural essential oil in Sophora japonica is also low in yield, and the content of essential oil obtained is low

At present, most methods can only extract plant essential oils from a single plant, and it is extremely necessary to develop a method that is fast and suitable for the extraction of various plant essential oils, and has high yield and high content of essential oils.