阅读说明：本技术 富集香樟精油抑菌成分的方法 (Method for enriching antibacterial components of cinnamomum camphora essential oil ) 是由 邓刚 王芳 林洁茹 大卫.安德列亚 傅新媛 于 2020-04-26 设计创作，主要内容包括：本发明公开了一种富集香樟精油中抑菌成分的方法,包括香樟精油的提取,还包括以下步骤：以香樟精油为原料,设定分子蒸馏蒸发温度为(60±2)℃、系统压力为(100±10)Pa、一级冷凝温度为(20±1)℃、二级冷凝温度为(-20±1)℃,进行第一阶段分子蒸馏；以所得的一级轻馏分(1D<Sub>L</Sub>)为原料,设置蒸发温度为(40±2)℃、系统压力为(150±10)Pa、一级冷凝温度为(15±1)℃、二级冷凝温度为(-20±1)℃,进行第二阶段分子蒸馏；得二级轻馏分(2D<Sub>L</Sub>)。采用本发明的方法能有效保护精油成分不被破坏。(The invention discloses a method for enriching bacteriostatic components in camphor essential oil, which comprises the following steps of extracting the camphor essential oil: performing first-stage molecular distillation by using Cinnamomum camphora essential oil as raw material and setting molecular distillation evaporation temperature at 60 + -2 deg.C, system pressure at 100 + -10 Pa, primary condensation temperature at 20 + -1 deg.C, and secondary condensation temperature at-20 + -1 deg.C; with the resulting first light fraction (1D) L ) Setting evaporation temperature at 40 + -2 deg.C, system pressure at 150 + -10 Pa, primary condensation temperature at 15 + -1 deg.C, and secondary condensation temperature at-20 + -1 deg.C as raw materials, and performing second-stage molecular distillation; obtaining a second-grade light fraction (2D) L ). The method of the invention can effectively protect essential oil components from being damaged.)

1. The method for enriching antibacterial components in camphor essential oil comprises the extraction of camphor essential oil, and is characterized in that: the method comprises the following steps:

first), first stage molecular distillation:

performing first-stage molecular distillation by using Cinnamomum camphora essential oil as raw material and setting molecular distillation evaporation temperature at 60 + -2 deg.C, system pressure at 100 + -10 Pa, primary condensation temperature at 20 + -1 deg.C, and secondary condensation temperature at-20 + -1 deg.C;

the following three fractions were obtained, respectively: first heavy fraction (1R)_H) First middle distillate (1D)_M) And a first light fraction (1D)_L)；

Second), second stage molecular distillation:

with a first light fraction (1D)_L) Setting evaporation temperature at 40 + -2 deg.C, system pressure at 150 + -10 Pa, primary condensation temperature at 15 + -1 deg.C, and secondary condensation temperature at-20 + -1 deg.C as raw materials, and performing evaporation at the temperature of 40 + -2 deg.C, and performing secondary condensation at the temperature of 20 + -1 deg.CPerforming second-stage molecular distillation;

the following three fractions were obtained, respectively: second heavy fraction (2R)_H) Second middle distillate (2D)_M) And a second light fraction (2D)_L)。

2. The method for enriching bacteriostatic components in camphor essential oil as claimed in claim 1, which is characterized by comprising the following steps:

in the first step), the residence time of the camphor essential oil in the system is 8-12 s.

3. The method for enriching bacteriostatic components in cinnamomum camphora essential oil according to claim 1 or 2, which is characterized in that:

in the first step), the feeding flow rate is 2.5mL/min, and the film scraping rotation speed is 100 rpm.

4. The method for enriching bacteriostatic components in camphor essential oil according to any one of claims 1 to 3, which is characterized by comprising the following steps:

in the second step, the first-stage light fraction (1D)_L) The residence time in the system is 8-12 s.

5. The method for enriching bacteriostatic components in camphor essential oil as claimed in claim 4, which is characterized by comprising the following steps:

in the second step), the feeding flow rate is 2.5mL/min, and the film scraping rotation speed is 100 rpm.

Technical Field

The invention relates to a process for enriching antibacterial components of camphor essential oil.

Background

Cinnamomum camphora (Cinnamomum camphora), originating in southern china, vietnam, japan, etc., is a large evergreen tree widely distributed in the east asia, oceania, and pacific islands. The cinnamomum camphora is an important economic tree species in China and one of the tree species with the highest planting rate in urban greening, the planting area reaches more than 5 million hectares, and the cinnamomum camphora increases year by year. According to the pruning rate of 5% every year, branches and leaves generated by pruning only one medium-sized city can reach 3 ten thousand tons, and the waste branches and leaves can be used for extracting the camphor essential oil, so that the environmental pollution is effectively reduced. The essential oil extracted from the cinnamomum has various antibacterial activities, and can be widely used in industries of essence, spice, medicine and the like. However, in general, compared with the traditional bacteriostatic agent, the natural essential oil has weaker bacteriostatic activity, and because the plant essential oil is a complex mixture consisting of a series of volatile organic compounds, finding the target component with bacteriostatic effect is very difficult, so that if a proper separation technology can be found to enrich the components in the camphor essential oil, the specific bacteriostatic active ingredients in the essential oil can be expected to be determined, so that the bacteriostatic activity of the camphor essential oil can be improved, and the additional value of the essential oil product can be further increased.

In the method for concentrating the effective components in the essential oil, a chemical method is a traditional method for purifying the essential oil, but the prepared essential oil is generally low in purity, complex in process flow and easy to have solvent residues. The rectification method and the preparative gas chromatography have high separation degree, but have obvious defects, the rectification method usually needs higher temperature and is easy to damage components in the essential oil, and the preparative gas chromatography has high equipment requirement, has extremely small amount of the essential oil which can be separated, is mainly used for qualitative analysis of the essential oil components and cannot be used in large scale.

Currently, some new methods are attracting attention, wherein the molecular distillation is performed under the conditions of high vacuum degree and low evaporation temperature, the distance between the evaporator and the condenser is small, the residence time of the molecules in the heated area of the evaporator is short, so that the heat-sensitive substances can be effectively prevented from being damaged, no solvent is required to be used, and the problems of solvent residue and the like do not exist. The research shows that the molecular distillation can effectively enrich antioxidant active ingredients in the essential oil, concentrate essence flavor substances and remove impurities, so that the quality of the essential oil is improved, but the research on enriching antibacterial ingredients in the cinnamomum camphora essential oil by molecular distillation is not reported yet.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for enriching the antibacterial components of the camphor essential oil, which has the advantages of simple process, high antibacterial activity, safety, high efficiency, greenness and environmental protection.

In order to solve the technical problems, the invention provides a method for enriching bacteriostatic components of camphor essential oil, which comprises the following steps of:

first), first stage molecular distillation:

performing first-stage molecular distillation by using Cinnamomum camphora essential oil as raw material and setting molecular distillation evaporation temperature at 60 + -2 deg.C, system pressure at 100 + -10 Pa, primary condensation temperature at 20 + -1 deg.C, and secondary condensation temperature at-20 + -1 deg.C;

the following three fractions were obtained, respectively: first heavy fraction (1R)_H) First middle distillate (1D)_M) And a first light fraction (1D)_L)；

Second), second stage molecular distillation:

with a first light fraction (1D)_L) Setting evaporation temperature at 40 + -2 deg.C, system pressure at 150 + -10 Pa, primary condensation temperature at 15 + -1 deg.C, and secondary condensation temperature at-20 + -1 deg.C as raw materials, and performing second-stage molecular distillation;

the following three fractions were obtained, respectively: second heavy fraction (2R)_H) Second middle distillate (2D)_M) And a second light fraction (2D)_L)。

Second grade light fraction (2D)_L) The bacteriostatic effect is optimal.

The improvement of the method for enriching the antibacterial component in the camphor essential oil comprises the following steps: in the step one), the retention time of the camphor essential oil in the system (device) is 8-12 s.

The method for enriching the antibacterial component in the camphor essential oil is further improved as follows: in the first step), the feeding flow rate is 2.5mL/min, and the film scraping rotation speed is 100 rpm.

The method for enriching the antibacterial component in the camphor essential oil is further improved as follows: in the second step, the first-stage light fraction (1D)_L) The residence time in the system (device) is 8-12 s.

The method for enriching the antibacterial component in the camphor essential oil is further improved as follows: in the second step), the feeding flow rate is 2.5mL/min, and the film scraping rotation speed is 100 rpm.

In the invention, the extraction of the cinnamomum camphora essential oil is carried out in a conventional way: cleaning the branches and leaves of Cinnamomum camphora, drying in the shade at room temperature, drying, cutting into pieces, grinding into powder with liquid nitrogen, extracting by steam distillation, removing water with anhydrous sodium sulfate to obtain Cinnamomum camphora essential oil (crude oil), sealing, storing in brown glass bottle at 4 deg.C, and storing.

Molecular distillation: the raw material to be treated is placed in a molecular distillation device, and the evaporation intensity is adjusted by changing the evaporation temperature and the system pressure. Under the appropriate evaporation intensity, the temperature of the primary condenser is adjusted; the secondary condenser temperature was set at (-20 + -1) deg.C to ensure that all components reaching the secondary condenser were condensed. Three fractions can be obtained by each stage of molecular distillation: heavy fraction (R)_H) Middle distillate (D)_M) And a light fraction (D)_L). By adopting the method, the target components in the essential oil can be enriched in the corresponding fractions.

The first stage of molecular distillation takes camphor essential oil as raw material; in the second stage of molecular distillation, the fraction with high enrichment degree and enhanced bacteriostatic activity obtained in the first stage is used as a raw material. The invention adopts two-stage molecular distillation to further improve the concentration degree of the target component and obtain better enrichment effect and bacteriostatic activity.

In the invention, a gas chromatography-mass spectrometer (GC-MS) is adopted to carry out real-time analysis on chemical compositions of the cinnamomum camphora crude oil and each fraction obtained by molecular distillation, and the molecular distillation condition is adjusted through the flow direction of a target component.

The selection of the molecular distillation experimental conditions mainly considers the mass recovery rate of each fraction and the concentration ratio of main components of the essential oil. The recovery rate of each fraction is calculated by the formula:

the concentration ratio of the main components in each fraction is calculated according to the formula:

the concentration ratio of the target component is the ratio of the mass percentage of the target component in each fraction to the mass percentage of the corresponding component in the cinnamomum camphora crude oil. A concentration ratio greater than 1 indicates that the target component in the fraction is concentrated, i.e. effectively enriched by molecular distillation. The larger the concentration ratio, the better the enrichment effect.

The minimum inhibitory concentrations of the cinnamomum camphora crude oil and each fraction to two gram-positive bacteria (staphylococcus aureus and bacillus subtilis), two gram-negative bacteria (escherichia coli and pseudomonas aeruginosa) and two fungi (aspergillus niger and candida albicans) are respectively determined by a microdilution method. To more intuitively understand the gain or loss of bacteriostatic activity of each fraction after the two-stage molecular distillation, the bacteriostatic rating was defined in terms of the MIC value. The higher the MIC value is, the weaker the bacteriostatic effect of the essential oil is, and therefore the lower the bacteriostatic grade is. When the MIC value is 20 mug/mL, the bacteriostatic effect is a high-activity level; when the MIC value is gradually increased to 100 mu g/mL and 500 mu g/mL respectively, the bacteriostasis level is decreased to medium and high activity; when the MIC value is increased to 1000 mug/mL or more, the bacteriostatic effect is weak activity level and no activity level respectively.

The method for enriching the antibacterial components of the camphor essential oil is to enrich the antibacterial active components in the camphor essential oil by adopting two-stage molecular distillation; the method specifically comprises the steps of taking the cinnamomum camphora essential oil as a raw material, separating and concentrating components in the essential oil by utilizing two-stage molecular distillation, enriching components with bacteriostatic active ingredients in the essential oil, and improving the bacteriostatic activity of the cinnamomum camphora essential oil.

In the invention, the feeding flow rate is set to be 2.5mL/min, the rotating speed of the film scraping is set to be 100rpm, the retention time from the upper end to the lower end of the evaporator is about 10s after the essential oil enters the evaporation system, and a uniform film can be formed on the surface of the evaporator, thereby ensuring that the inflowing material can be fully evaporated.

Under the optimal operation conditions of the molecular distillation of the first stage, the recovery rate of each fraction is as follows: first heavy fraction (1R)_H) 13.79% of first middle distillate (1D)_M) 71.93%, first light fraction (1D)_L)10.17％。

Through two-stage molecular distillation, the target components in heavy fractions are alpha-terpineol and gamma-terpineol; the target components in the middle distillate are linalool and dihydrocarveol; the target components in the light fraction are methylheptenone and 1, 8-cineole.

After the two-stage molecular distillation of the invention, the first light fraction (1D)_L) The concentration ratio of the target components of methyl heptenone and 1, 8-cineole can be respectively up to 5.72 and 5.16, and the concentration ratio of the second-level light fraction (2D)_L) The concentration ratios of the two target components were further improved, and the final concentration ratios were 9.61 and 10.63, respectively.

The antibacterial activity of the camphor essential oil is two-stage molecular distillation, and then the two-stage light fraction (2D)_L) Compared with crude oil, the inhibitor has obviously improved inhibiting effect on staphylococcus aureus and bacillus subtilis, and certain enhancement on the inhibition of fungi.

The method for enriching the antibacterial components of the camphor essential oil has the following characteristics:

1) the proper evaporation intensity can be obtained by regulating and controlling the evaporation temperature and the system pressure;

2) adjusting the first-stage condensation temperature to enable the volatile essential oil target components to be condensed by two-stage condensers respectively, so that the volatile essential oil target components are enriched in corresponding fractions;

3) the second stage of molecular distillation can further obtain better enrichment effect of target components;

4) the operation process is low in temperature and oxygen-isolated, and the components with heat sensitivity and easy oxidation are protected;

5) the real-time analysis of GC-MS is combined, so that the molecular distillation condition can be better adjusted;

6) the camphor essential oil has obvious bacteriostatic component enrichment effect and obviously improved bacteriostatic activity.

In conclusion, the method adopts two-stage molecular distillation, has the advantages of low system pressure, mild evaporation temperature, short component heating time, adjustable primary condensation temperature, environmental protection and the like, and effectively protects essential oil components from being damaged compared with the traditional essential oil component concentration method.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of two-stage molecular distillation for enriching the components of Cinnamomum camphora essential oil;

FIG. 2 is a schematic view of a molecular distillation apparatus.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto:

the following examples were carried out in a conventional molecular distillation apparatus as shown in FIG. 2, which consists of four sections of evaporation system, vacuum system, heating and condensing, feeding and discharging.

After the essential oil material enters the evaporator from the feeding device at the top of the evaporator, an even film is formed on the surface of the evaporator under the rotating wiping action of the scraper, so that the evaporation area of the material is increased, and the material can be uniformly heated. Under proper evaporation intensity, most of the non-volatile components (dark background color in fig. 1 a) in the essential oil material with film-shaped evaporator surface can not be vaporized, and will flow out along the evaporator wall to become first-order heavy fraction (1R)_H) (ii) a After the volatile component has evaporated, it is due to the molecular mean free path (And) Above the distillation distance, it can escape from the oil film layer and reach the condenser, and after the components (light background color number in FIG. 1 a) captured by the primary condenser flow out, a primary middle distillate (1D) is formed_M) (ii) a While a small portion of the components (no background color numbers in fig. 1 a) with mean free path much larger than the distillation distance will "bounce" to the secondary condenser and become the first light fraction (1D) due to incomplete condensation on the first condenser_L). Then the first-grade light fraction (1D) with high enrichment degree of target components and obviously enhanced antibacterial activity is used_L) A second stage of molecular distillation was carried out on the batch to obtain further three fractions: second heavy fraction (2R)_H) Second middle distillate (2D)_M) Second grade light ends (2D)_L)。