1. The extraction method of the rhododendron essential oil is characterized by comprising the following steps of:

(1) mixing and pulverizing branches and leaves of snow-layer rhododendron;

(2) distilling and extracting in a water distillation device to obtain crude essential oil;

(3) centrifuging the crude essential oil obtained in the step (2), taking the upper clear essential oil, adding a drying agent, and drying until the essential oil is clear and transparent;

(4) sealing and aging the essential oil obtained in the step (3) for three days at normal temperature in a dark place;

(5) and (3) separating and finely extracting the aged essential oil on molecular distillation equipment to obtain the snow rhododendron essential oil.

2. The extraction method according to claim 1, characterized in that: the snow-layer rhododendron is grown in Tibet Quilashan or Milin county.

3. The extraction method according to claim 1, characterized in that: in the step (1), the crushed mesh number is 200-400 meshes.

4. The extraction method according to claim 1, characterized in that: in the step (2), the distillation extraction process is to add water into a water distillation device for extraction, wherein the water adding proportion is that the plant: 1 part of water: and 8, boiling and refluxing for 2h, and collecting refluxed crude essential oil.

5. The extraction method according to claim 1, characterized in that: in the step (3), the speed of centrifugal separation is 3000-10000 rpm, and the time is 3-20 min.

6. The extraction method according to claim 1, characterized in that: in the step (3), the drying agent is anhydrous sodium sulfate or salt bars obtained by drying and removing water.

7. The extraction method according to claim 1, characterized in that: in the step (4), the environmental temperature during aging and standing is 8-35 ℃.

8. The extraction method according to claim 1, characterized in that: in the step (5), the separation and fine extraction is a secondary separation, the temperature of the primary separation is 60-80 ℃, and the stirring speed is 180-220 r/min; the temperature of the secondary separation is 80-150 ℃, and the stirring speed is 180-250 r/min.

9. The rhododendron hybridum essential oil obtained by the extraction method according to claims 1 to 8, which is characterized by comprising the following components in parts by mass:

10. use of the essential oil of rhododendron hybridum according to claim 9 as a raw material for household cleaning products, perfumes, daily necessities, and cosmetics.

Background

In recent years, with the improvement of the pursuit of green, health and environmental protection, the development of the green natural plants has been more and more valued by people. And the special geographical location and ecological environment of Tibet make it possess unique plant population because of being in the third pole of the world. Can be used in cold environment and in scarce material condition, and most research workers forget to do the work. In Tibet regions where natural plant resources are abundant and developed to a considerable extent, such sustainable green development is being demanded.

Snow-layer rhododendron is a evergreen shrub of rhododendron of Ericaceae, has many branches and is dense, and can be laid into a cushion shape; capsule round to oval, squashed; the flowering period is 5-8 months, and the fruit period is 8-9 months; distributed in southeast, south, east and northeast of the Tibet of China, and Nepal, India, Plumbum preparatium and Centanium are also distributed. The snow-layer rhododendron comes from mountain shrubs, glacier valley and meadows, the altitude is 3200-5800 meters, the snow-layer rhododendron has cultivation and gardening values due to the beauty of flowers, meanwhile, the tender branches and leaves of the snow-layer rhododendron can be used for relieving cough and eliminating phlegm, and the snow-layer rhododendron has special aromatic smell as a plant in a Tibetan region.

At present, the same type of products similar to the snow rhododendron essential oil are not available in the market.

Disclosure of Invention

The invention aims to provide an extraction method for extracting and preparing snow-layer rhododendron essential oil by utilizing rhododendron branches and leaves in the south Tibetan region, which is characterized in that the snow-layer rhododendron essential oil with better fragrance is obtained by evaluating and analyzing the fragrance of the snow-layer rhododendron essential oil and directionally carrying out refined extraction and impurity removal, so that a unique natural raw material with characteristics of the Tibetan region is provided for fragrance blending of perfume and daily chemical essence, and the problem that the blank of the characteristic rhododendron essential oil of the Tibetan region does not exist in the fragrance raw material market in the prior art is solved.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a method for extracting snow rhododendron essential oil, which comprises the following steps:

(1) mixing and pulverizing branches and leaves of snow-layer rhododendron;

(2) distilling and extracting in a water distillation device to obtain crude essential oil;

(3) centrifuging the crude essential oil obtained in the step (2), taking the upper clear essential oil, adding a drying agent, and drying until the essential oil is clear and transparent;

(4) sealing and aging the essential oil obtained in the step (3) for three days at normal temperature in a dark place;

(5) and (3) separating and finely extracting the aged essential oil on molecular distillation equipment to obtain the snow rhododendron essential oil.

In some specific embodiments, the snow-layer azalea is a snow-layer azalea grown in Quilashan, Tibet or Milin county.

In some specific embodiments, in the step (1), the crushed mesh number is 200-400 mesh.

In some specific embodiments, in step (2), the distillation extraction process is water extraction in a water distillation device, and the water ratio is plant: 1 part of water: and 8, boiling and refluxing for 2h, and collecting refluxed crude essential oil.

In some specific embodiments, in step (3), the centrifugation is performed at a rate of 3000 to 10000rpm for 3 to 20 min.

In some specific embodiments, in step (3), the drying agent is anhydrous sodium sulfate or dried and dehydrated salt.

In some specific embodiments, in the step (4), the ambient temperature of the aging and standing is 8-35 ℃.

In some specific embodiments, in the step (5), the separation and fine extraction is a secondary separation, the temperature of the primary separation is 60-80 ℃, and the stirring speed is 180-220 r/min; the temperature of the secondary separation is 80-150 ℃, and the stirring speed is 180-250 r/min.

In a second aspect, the invention provides a rhododendron essential oil obtained by the above extraction method.

Preferably, the snow rhododendron essential oil comprises the following components in parts by mass:

in a third aspect, the invention also provides application of the snow rhododendron essential oil.

Specifically, a proper amount of the rhododendron essential oil can be used as a raw material to be added into household cleaning products, perfume, daily necessities and cosmetics, so that the products have special fragrance.

Compared with the prior art, the invention provides snow rhododendron essential oil and an extraction method and application thereof, and the snow rhododendron essential oil has the following beneficial effects:

the snow rhododendron essential oil extracted by the method is relatively appropriate in reduction of the fragrance of the plant snow rhododendron; because of using the water distillation extraction process, the plant is completely soaked in water and has higher temperature, the occurrence of unpredictable side reactions is inevitable, and other unpleasant miscellaneous gases are easy to generate, and the balance between the yield and the aroma quality is found as much as possible on the process parameter setting; by the process method, interference of side reaction on the quality of the snow rhododendron essential oil can be eliminated only by aging for a short time, and the aroma quality of the snow rhododendron essential oil can be used as an essence raw material component to be applied to products such as household cleaning products, perfumes, daily necessities, cosmetics and the like.

Detailed Description

The technical solutions of the present invention will be described clearly and completely by the detailed embodiments, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following examples, the drying agent is anhydrous sodium sulfate or dried salt. The used water distillation equipment, centrifuge and separation distillation equipment are all commercial product equipment.

Example 1

The embodiment provides an extraction method of snow rhododendron essential oil, which comprises the following steps:

(1) taking twigs and leaves of snow-layer rhododendron growing in Tibet Quilashan, mixing and crushing to 100-200 meshes;

(2) adding water into a water distillation device for extraction, wherein the water adding proportion is that the plants: 1 part of water: boiling and refluxing for 2h, and collecting refluxed crude essential oil;

(3) centrifuging the crude essential oil obtained in the step (2) by using a centrifuge, wherein the speed of centrifugal separation is 6000rpm, the time is 10min, taking the upper clear essential oil, adding a drying agent, drying until the essential oil is clear and transparent, and completely removing water;

(4) sealing and aging the dehydrated essential oil obtained in the step (3) for three days at normal temperature in a dark place, wherein the normal temperature refers to the ambient temperature of 8-35 ℃;

(5) and (3) carrying out separation and fine extraction on the aged essential oil on molecular distillation equipment, wherein the temperature of the first-stage separation is 70 ℃, the stirring speed is 180r/min, the temperature of the second-stage separation is 120 ℃, and the stirring speed is 220r/min, so as to obtain the snow-layer rhododendron essential oil.

Example 2

The embodiment provides an extraction method of snow rhododendron essential oil, which comprises the following steps:

(1) taking twigs and leaves of snow-layer rhododendron growing in Milin county of Tibet, mixing and crushing to 100-200 meshes;

(2) adding water into a water distillation device for extraction, wherein the water adding proportion is that the plants: 1 part of water: boiling and refluxing for 2h, and collecting refluxed crude essential oil;

(3) centrifuging the crude essential oil obtained in the step (2) by using a centrifuge, wherein the speed of centrifugal separation is 6000rpm, the time is 10min, taking the upper clear essential oil, adding a drying agent, drying until the essential oil is clear and transparent, and completely removing water;

(4) sealing and aging the dehydrated essential oil obtained in the step (3) for three days at normal temperature in a dark place, wherein the normal temperature refers to the ambient temperature of 8-35 ℃;

(5) and (3) carrying out separation and fine extraction on the aged essential oil on molecular distillation equipment, wherein the temperature of the first-stage separation is 70 ℃, the stirring speed is 180r/min, the temperature of the second-stage separation is 120 ℃, and the stirring speed is 220r/min, so as to obtain the snow-layer rhododendron essential oil.

Example 3

The embodiment provides an extraction method of snow rhododendron essential oil, which comprises the following steps:

(1) taking twigs and leaves of snow-layer rhododendron growing in Tibet Quilashan, mixing and crushing to 100-200 meshes;

(2) adding water into a water distillation device for extraction, wherein the water adding proportion is that the plants: 1 part of water: boiling and refluxing for 5h, and collecting refluxed crude essential oil;

(3) centrifuging the crude essential oil obtained in the step (2) by using a centrifuge, wherein the speed of centrifugal separation is 6000rpm, the time is 10min, taking the upper clear essential oil, adding a drying agent, drying until the essential oil is clear and transparent, and completely removing water;

(4) and (4) carrying out separation and fine extraction on the essential oil obtained in the step (3) on molecular distillation equipment, wherein the temperature of the first-stage separation is 70 ℃, the stirring speed is 180r/min, the temperature of the second-stage separation is 120 ℃, and the stirring speed is 220r/min, so as to obtain the rhododendron hybridum essential oil.

Example 4

The embodiment provides an extraction method of snow rhododendron essential oil, which comprises the following steps:

(1) taking twigs and leaves of snow-layer rhododendron growing in Tibet Quilashan, mixing and crushing to 100-200 meshes;

(2) adding water into a water distillation device for extraction, wherein the water adding proportion is that the plants: 1 part of water: boiling and refluxing for 4h, and collecting refluxed crude essential oil;

(3) centrifuging the crude essential oil obtained in the step (2) by using a centrifuge, wherein the speed of centrifugal separation is 6000rpm, the time is 10min, taking the upper clear essential oil, adding a drying agent, drying until the essential oil is clear and transparent, and completely removing water;

(4) sealing and aging the dehydrated essential oil obtained in the step (3) for three days at normal temperature in a dark place, wherein the normal temperature refers to the ambient temperature of 8-35 ℃;

(5) and (3) carrying out separation and fine extraction on the aged essential oil on molecular distillation equipment, wherein the temperature of the first-stage separation is 70 ℃, the stirring speed is 180r/min, the temperature of the second-stage separation is 120 ℃, and the stirring speed is 220r/min, so as to obtain the snow-layer rhododendron essential oil.

Example 5

The embodiment provides an extraction method of snow rhododendron essential oil, which comprises the following steps:

(1) taking twigs and leaves of snow-layer rhododendron growing in Tibet Quilashan, mixing and crushing to 100-200 meshes;

(2) adding water into a water distillation device for extraction, wherein the water adding proportion is that the plants: 1 part of water: boiling and refluxing for 1h, and collecting refluxed crude essential oil;

(3) centrifuging the crude essential oil obtained in the step (2) by using a centrifuge, wherein the speed of centrifugal separation is 6000rpm, the time is 10min, taking the upper clear essential oil, adding a drying agent, drying until the essential oil is clear and transparent, and completely removing water;

(4) sealing and aging the dehydrated essential oil obtained in the step (3) for three days at normal temperature in a dark place, wherein the normal temperature refers to the ambient temperature of 8-35 ℃;

(5) and (3) carrying out separation and fine extraction on the aged essential oil on molecular distillation equipment, wherein the temperature of the first-stage separation is 70 ℃, the stirring speed is 180r/min, the temperature of the second-stage separation is 120 ℃, and the stirring speed is 220r/min, so as to obtain the snow-layer rhododendron essential oil.

Example 6

The embodiment provides an extraction method of snow rhododendron essential oil, which comprises the following steps:

(1) taking twigs and leaves of snow-layer rhododendron growing in Tibet Quilashan, mixing and crushing to 100-200 meshes;

(2) adding water into a water distillation device for extraction, wherein the water adding proportion is that the plants: 1 part of water: boiling and refluxing for 2h, and collecting refluxed crude essential oil;

(3) centrifuging the crude essential oil obtained in the step (2) by using a centrifuge, wherein the speed of centrifugal separation is 6000rpm, the time is 10min, taking the upper clear essential oil, adding a drying agent, drying until the essential oil is clear and transparent, and completely removing water;

(4) sealing and aging the dehydrated essential oil obtained in the step (3) for three days at normal temperature in a dark place, wherein the normal temperature refers to the ambient temperature of 8-35 ℃;

(5) and (3) carrying out separation and fine extraction on the aged essential oil on molecular distillation equipment, wherein the temperature of the first-stage separation is 60 ℃, the stirring speed is 180r/min, the temperature of the second-stage separation is 130 ℃, and the stirring speed is 220r/min, so as to obtain the snow-layer rhododendron essential oil.

Example 7

The embodiment provides an extraction method of snow rhododendron essential oil, which comprises the following steps:

(1) taking twigs and leaves of snow-layer rhododendron growing in Tibet Quilashan, mixing and crushing to 100-200 meshes;

(2) adding water into a water distillation device for extraction, wherein the water adding proportion is that the plants: 1 part of water: boiling and refluxing for 2h, and collecting refluxed crude essential oil;

(3) centrifuging the crude essential oil obtained in the step (2) by using a centrifuge, wherein the speed of centrifugal separation is 6000rpm, the time is 10min, taking the upper clear essential oil, adding a drying agent, drying until the essential oil is clear and transparent, and completely removing water;

(4) sealing and aging the dehydrated essential oil obtained in the step (3) for three days at normal temperature in a dark place, wherein the normal temperature refers to the ambient temperature of 8-35 ℃;

(5) distilling the aged essential oil under reduced pressure on molecular distillation equipment, heating at 70-120 deg.C in a gradient manner, and distilling at 10 deg.C for 15 min from 70 deg.C until the temperature is 120 deg.C to obtain the Rhododendron hybridum essential oil.

The snow rhododendron essential oil prepared in the above examples 1 to 7 was subjected to effective component detection and aroma evaluation. Wherein the main sources of specific aroma in the rhododendron essential oil comprise limonene (with fruity aroma), cadinene (radix aucklandiae), borneol and bornyl acetate (all of which can bring cool mint feeling).

Specifically, the evaluation results of the composition comparison of the snow rhododendron essential oil prepared in examples 1 to 7 are shown in the following table 1:

TABLE 1

Examples	Limonene	Borneol acetate	Alpha-cadinenes	Delta-cadinenes	Borneol (borneol)
						1	0.307	1.008	5.550	20.098	0.101
2	0.725	0.913	3.919	17.433	0.143
						3	0.305	1.157	3.831	25.053	0.109
4	0.058	0.395	6.402	23.503	0.030
						5	0.262	1.038	5.789	19.624	0.088
6	0.253	0.993	5.809	19.935	0.012
						7	0.054	0.653	8.758	13.384	0.114

Note: the data in table 1 are in percent.

The following table 2 is summarized in combination with the information on the yield, state, aroma and production area of examples 1 to 7:

TABLE 2

Examples	Yield (%)	Status of state	Fragrance	Origin of raw materials
					1	2.2	Yellow transparent liquid	Rich snow-covered rhododendron odor	Mount Laplace in Christian province
2	1.8	Yellow transparent liquid	Rich snow-covered rhododendron odor	Milin county
					3	2.2	Yellow transparent liquid	Smell of boiling in water, weak fragrance of snow-layer rhododendron	Mount Laplace in Christian province
4	2.4	Yellow transparent liquid	Smell of boiling in water, weak fragrance of snow-layer rhododendron	Mount Laplace in Christian province
					5	1.8	Yellow transparent liquid	Rich snow-covered rhododendron odor	Mount Laplace in Christian province
6	2.2	Yellow transparent liquid	Fragrant of snow-layer rhododendron and weak sense of mint	Mount Laplace in Christian province
					7	2.0	Yellow transparent liquid	The fragrance of the rhododendron with the snow layer is lost	Mount Laplace in Christian province

From the results of tables 1 and 2, it is understood that the yield and flavor of example 1 are optimum. From examples 1 to 7 and evaluation results, it can be seen that the snow rhododendron essential oil with good state and better aroma quality can be extracted by using water distillation extraction combined with fine extraction and impurity removal of molecular distillation equipment under the process conditions of example 1.

In addition, as an example, the rhododendron hybridum essential oil extracted and prepared in the example 1 is taken as a raw material and is respectively added into a household cleaning product, perfume, daily necessities and cosmetics in a proper amount, and detection shows that the product added with the rhododendron hybridum essential oil has special and rich rhododendron hybridum aroma.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.