Technological method for treating aromatic plant essential oil through combination of molecular distillation and microbial decomposition

Abstract

The invention discloses a technological method for treating aromatic plant essential oil through combination of molecular distillation and microbial decomposition, and belongs to the technical field of treatment of plasticizers in aromatic plant essential oil. The method comprises the following steps: feeding essential oil with plasticizer indexes DBP and DEHP exceeding standards into molecular distillation equipment to obtain first heavy component essential oil and light component primary essential oil; feeding the first light component primary essential oil into molecular distillation equipment to obtain second heavy component essential oil and light component pure essential oil; adding similar hydrolat containing microorganisms into the mixed solution of the first heavy component essential oil and the second heavy component essential oil, and then carrying out constant-temperature culture to obtain a mixed solution subjected to microbial decomposition; performing distillation treatment and oil-water separation to obtain third heavy component essential oil, and performing dehydration and filtration treatment to obtain fourth heavy component essential oil; and finally, mixing the fourth heavy component essential oil with the light component pure essential oil to obtain an essential oil finished product. No plasticizer is detected in the essential oil finished product treated by the method, and meanwhile, the original fragrance of aromatic plants is restored.

Description

Technical Field

[0001] The invention belongs to the technical field of plasticizer treatment in aromatic plant essential oils, and specifically relates to a process for treating aromatic plant essential oils by combining molecular distillation with microbial decomposition. Background Art

[0002] In the prior art, most of the plasticizers in aromatic plant essential oils are treated by chemical solvent treatment, such as adding organic solvents such as methanol and isopropanol, and then extracting most of the solvents by corresponding methods. Using this method to treat aromatic plant essential oils can reduce the plasticizer index to a certain extent, but it cannot completely remove the plasticizer in the essential oils. At the same time, the essential oils treated in this way still have the problem of solvent residue, which affects both the safety of the essential oils and the authentic plant aroma of the essential oils. Summary of the invention

[0003] The purpose of the present invention is to provide for the first time a process method for treating aromatic plant essential oils by combining molecular distillation and microbial decomposition. No plasticizer is detected in any index of the aromatic plant essential oils treated by the process method. At the same time, the entire process is a physical treatment process without any chemical residues, which not only ensures the safety of the essential oils, but also restores the authentic aroma of the aromatic plants.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A process for treating aromatic plant essential oil by combining molecular distillation and microbial decomposition, comprising the following steps:

[0006] S1. Select aromatic plant essential oils that have been tested for excessive plasticizers such as DBP and DEHP;

[0007] S2, feeding the aromatic plant essential oil into a molecular distillation device, and after molecular distillation treatment, obtaining a first heavy component essential oil and a light component primary essential oil;

[0008] S3, the first light component primary essential oil is fed again into a molecular distillation device, and after molecular distillation treatment, a second heavy component essential oil and a light component pure essential oil are obtained;

[0009] S4, mixing the first recombinant essential oil and the second recombinant essential oil, adding thereto a pure dew having a normal aroma and appearance but containing microorganisms and belonging to the same aromatic plant as the essential oil, and stirring thoroughly to obtain a mixed solution;

[0010] S5, placing the mixed solution in a constant temperature incubator, and obtaining a mixed solution after the microorganisms have fully decomposed the plasticizer;

[0011] S6. Feed the mixed liquid after microbial decomposition into a distillation device. After distillation treatment, collect the third recombinant essential oil obtained from oil-water separation, and perform dehydration and filtration on the third recombinant essential oil to obtain the fourth recombinant essential oil;

[0012] S7. Mix the obtained fourth recombinant essential oil with the light-component pure essential oil obtained in step S3 to obtain a finished aromatic plant essential oil with qualified plasticizer indicators.

[0013] In the present invention, in step S2, first-stage molecular distillation is performed on rose essential oil with unqualified plasticizer indicators (DBP, DEHP) to obtain the first recombinant essential oil and the light-component primary essential oil. Among them, DBP and DEHP are enriched in the first recombinant essential oil, while a small amount of DBP is contained in the light-component primary essential oil.

[0014] In step S3, second-stage molecular distillation is performed on the light-component primary essential oil to obtain the second recombinant essential oil and the light-component pure essential oil. The purpose of the second-stage molecular distillation is to completely remove the residual plasticizer DBP in the light-component primary essential oil into the second recombinant essential oil. Since the molecular weight of the plasticizer DBP is larger than that of the light-component pure essential oil, through molecular distillation treatment, the plasticizer DBP can be completely separated and removed from the light-component primary essential oil.

[0015] In step S4, hydrosol is added to the first and second recombinant essential oils containing plasticizers (DBP, DEHP) obtained from the first-stage and second-stage molecular distillations for blending and dilution, so that the essential oil has the conditions for microbial decomposition (the concentration of the essential oil without blending and dilution is high, which has the effect of killing microorganisms and cannot allow microorganisms to survive, and cannot reach the conditions for microbial decomposition).

[0016] In step S5, by maintaining a constant temperature for a certain period of time for the diluted and blended recombinant essential oil containing plasticizers, the plasticizers in the recombinant essential oil are completely decomposed by microbial treatment to achieve the purpose of removing plasticizers.

[0017] In step S6, after microbial decomposition, the diluted essential oil is re-distilled and extracted by a re-distillation method. After such treatment, a fourth recombinant rose oil with qualified plasticizer (DBP, DEHP) indicators can be obtained.

[0018] In step S7, finally, the qualified light-component pure essential oil and the fourth recombinant essential oil are mixed to produce a finished aromatic plant essential oil with qualified plasticizer indicators.

[0019] In summary, the present invention adopts a combined treatment method of molecular distillation and microbial decomposition to treat plasticizers, and can obtain a finished product of aromatic plant essential oil without detectable plasticizers. Moreover, the entire process is a physical process treatment without chemical residues, which not only ensures the safety of the essential oil but also restores the true aroma of the plant. Specifically, taking rose essential oil as an example, there are about more than 300 common components in rose essential oil. Classified by molecular weight, there are mainly two types, namely heavy molecules and light molecules. The molecular weight of heavy molecules is about 240 - 400, and the molecular weight of light molecules is about 120 - 180. The molecular weights of plasticizers DBP and DEHP are similar to those of heavy molecules. Through the first-stage molecular distillation treatment, the plasticizers in rose essential oil can be enriched in the first heavy-component essential oil, and the plasticizers in most of the light-component rose essential oil can be removed. Through the second-stage molecular distillation treatment, a small amount of plasticizers remaining in the light-component essential oil can be completely removed to the second heavy-component essential oil. Subsequently, the first and second heavy-component essential oils are subjected to microbial decomposition treatment (using the principle of microbial absorption and metabolism to completely remove and decompose the plasticizers in the heavy-component essential oil) and distillation treatment to obtain heavy-component rose essential oil without DBP and DEHP. Finally, the light and heavy rose essential oils without DBP and DEHP are mixed to obtain a qualified finished product of rose essential oil.

[0020] As some feasible embodiments of the present application, in step S2, the process parameters of molecular distillation are as follows: the feeding temperature is 35°C - 40°C, the feeding speed is 30 - 35 rpm / min, the vacuum is 1 - 2 mbar, the scraper rotation speed is 260 - 280 rpm / min, the heating evaporation temperature is 60 - 65°C, and the condensation temperature is 5 - 10°C.

[0021] As some feasible embodiments of the present application, in step S3, the process parameters of molecular distillation are as follows: the feeding temperature is 35°C - 40°C, the feeding speed is 30 - 35 rpm / min, the vacuum degree is 1 - 2 mbar, the scraper rotation speed is 220 - 230 rpm / min, the heating evaporation temperature is 50 - 55°C, and the condensation temperature is 5 - 10°C.

[0022] As some feasible embodiments of the present application, in step S4, the mass ratio of essential oil to hydrosol is 5:1000; the temperature of the hydrosol is 36°C ± 1°C.

[0023] As some feasible embodiments of the present application, in step S4, the microorganisms in the hydrosol are Pseudomonas, Bacillus, and Fusarium fujikuroi. In terms of the selection of microorganisms, initially, strains such as yeast were used to treat the first and second recombinant essential oils. After treatment, it would cause the recombinant essential oils to ferment during the decomposition process, producing a sour taste and reducing the aroma quality of the essential oils. After extensive research and development, it was finally determined to select the by-product hydrosol of the same type as the essential oil. This by-product hydrosol is not sterilized and contains a large number of original microorganisms (Pseudomonas, Bacillus, Fusarium fujikuroi). Through the cultivation of these microorganisms, the purpose of decomposing phthalates is achieved. Specifically, the Pseudomonas, Bacillus, and Fusarium fujikuroi complex shows a relatively high degradation efficiency for plastic polymers. Pseudomonas and Bacillus are bacteria, and bacterial strains can effectively degrade contaminated raw materials or plastic polymer substances. Although the plastic degradation rate of fungi exceeds that of bacteria, compared with fungi that require more stable conditions, bacteria are easier to grow and degrade polymer materials. The Fusarium fujikuroi complex is a fungus, and fungal hyphae can effectively penetrate the surface of polymer materials and penetrate deep into the groups inside to degrade the largest structure of the substrate. In addition, fungal hyphae can secrete extracellular enzymes (such as depolymerases) and decompose the polymer substrate into oligomers, dimers, and monomers. These monomers are then absorbed by the fungi or assimilated or mineralized by their intracellular enzyme systems. The amount of enzymes produced and secreted by fungi is significantly higher than that of bacteria, and it can effectively degrade the phthalates in the essential oils.

[0024] As some feasible embodiments of the present application, in step S5, the decomposition temperature for the microorganisms to fully decompose phthalates is 36°C ± 1°C, and the decomposition time is 120 h.

[0025] As some feasible embodiments of the present application, in step S6, the process parameters for the distillation treatment are: the heating temperature is 98°C, the condensation temperature is 15°C, the evaporation flow rate is 4 - 5 L / h, and the distillation time is 1 h.

[0026] As some feasible embodiments of the present application, the aromatic plant essential oil is rose essential oil, and the molecular weights of the components in the first recombinant essential oil, the second recombinant essential oil, the third recombinant essential oil, and the fourth recombinant essential oil are all 240 - 400; the molecular weights of the components in the light-component pure essential oil are 120 - 180.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] The present invention adopts a method combining molecular distillation treatment of plasticizers and microbial decomposition treatment of plasticizers, which can obtain a finished product of aromatic plant essential oil with undetectable plasticizers. Moreover, the whole process is a physical process treatment without chemical residues, which not only ensures the safety of the finished essential oil product but also restores the true aroma of aromatic plants and guarantees the quality of the finished essential oil product. Specifically, through the first and second-stage molecular distillation treatment, the plasticizers in the aromatic plant essential oil are completely removed into the first and second heavy-component essential oils, and the plasticizers in the light-component pure essential oil are completely removed. Subsequently, the first and second heavy-component essential oils are subjected to microbial decomposition treatment (using the principle of microbial absorption and metabolism to completely remove and decompose the plasticizers in the heavy-component essential oil) and distillation treatment to obtain a heavy-component rose essential oil without DBP and DEHP. Finally, the light and heavy rose essential oils without DBP and DEHP are mixed to obtain a qualified finished product of aromatic plant essential oil. Detailed implementation mode

[0029] Example 1

[0030] S1 Select rose essential oil with plasticizer indicators (DBP, DEHP) exceeding the standard. The specific contents of DBP and DEHP are shown in Table 1.

[0031] S2 Feed the rose essential oil into the molecular distillation equipment and control the molecular distillation process parameters: feed temperature 35°C, feed rate 30 rpm / min, vacuum degree 1 mbar, scraper speed 260 rpm / min, heating evaporation temperature 60°C, condensation temperature 5°C. After molecular distillation treatment, 30% of the first heavy-component essential oil and 70% of the light-component primary essential oil in the weight ratio of the input raw materials are obtained.

[0032] S3 Feed the obtained 70% light-component primary essential oil into the molecular distillation equipment again and control the molecular distillation process parameters: feed temperature 35°C, feed rate 30 rpm / min, vacuum degree 1.5 mbar, scraper speed 220 rpm / min, heating evaporation temperature 52°C, condensation temperature 6°C. After molecular distillation treatment, 10% of the second heavy-component essential oil and 90% of the light-component pure essential oil in the weight ratio of the input raw materials are obtained.

[0033] S4 Mix the first and second heavy-component essential oils obtained in Steps S2 and S3 respectively and add rose hydrosol with normal aroma and appearance but containing a large number of microorganisms (Pseudomonas, Bacillus, Fusarium fujikuroi complex) (the total mass ratio of the first and second heavy-component essential oils to the mass of rose hydrosol is 5:1000). Among them, the temperature of the added rose hydrosol is 37°C. Use a magnetic stirrer to stir and mix the added rose hydrosol and the first and second heavy-component essential oils until the mixture is uniform. Use glass bottles or stainless steel tanks to subpackage the mixture, and lay a layer of non-woven fabric on the lid to ensure that the liquid in the tank can breathe.

[0034] S5 Put the mixed solution into an incubator, set the decomposition temperature at 36°C and the decomposition time at 120 h to obtain the mixed solution after microbial decomposition.

[0035] S6 Feed the mixed solution after microbial decomposition into a distillation device, control the heating temperature of the distiller at 98°C, the condensation temperature at 15°C, the evaporation flow rate at 4.5 L / h, and the distillation time at 1 h. Collect the third recombinant essential oil obtained by oil-water separation, and perform dehydration and filtration on the third recombinant essential oil to obtain a clean fourth recombinant essential oil.

[0036] S7 Mix the obtained fourth recombinant essential oil with the light-component pure essential oil obtained in step S3 to obtain a finished rose essential oil with qualified plasticizer indexes.

[0037] Detect the plasticizer content of some components in Example 1.

[0038] 1. In Example 1, the detection data of the plasticizer content in the 30% first recombinant essential oil and 70% light-component primary essential oil obtained in step S2 and the plasticizer content of the rose essential oil before treatment are shown in Table 1.

[0039] Table 1:

[0040]

[0041]

[0042] 2. The detection data of the plasticizer content in the 10% recombinant essential oil and 90% light-component pure essential oil obtained in step S3 and the plasticizer content of the rose essential oil before treatment (i.e., 70% light-component primary essential oil) are shown in Table 2.

[0043] Table 2:

[0044]

[0045] Example 2

[0046] S1 Select rose essential oil with plasticizer indexes (DBP, DEHP) exceeding the standard. The specific contents of DBP and DEHP are shown in Table 1.

[0047] S2 Feed the rose essential oil into a molecular distillation device, control the molecular distillation process parameters: feed temperature 40°C, feed rate 35 rpm / min, vacuum degree 1 mbar, scraper rotation speed 280 rpm / min, heating evaporation temperature 60°C, condensation temperature 10°C. After molecular distillation treatment, obtain the first recombinant essential oil and light-component primary essential oil.

[0048] S3 feeds the obtained light-component crude essential oil into the molecular distillation equipment again, and controls the molecular distillation process parameters: the feeding temperature is 40°C, the feeding speed is 35 rpm / min, the vacuum degree is 2 mbar, the scraper speed is 22 rpm / min, the heating evaporation temperature is 55°C, and the condensation temperature is 5°C. After molecular distillation treatment, the second heavy-component essential oil and the light-component pure essential oil are obtained.

[0049] S4 mixes the first and second heavy-component essential oils obtained from step S2 and step S3 respectively, and adds rose hydrosol with normal aroma and appearance but containing a large number of microorganisms (Pseudomonas, Bacillus, Fusarium fujikuroi complex) (the mass ratio of the total mass of the first and second heavy-component essential oils to the mass of the rose hydrosol is 5:1000). Among them, the temperature of the added rose hydrosol is 36°C. Use a magnetic stirrer to stir and mix the added rose hydrosol and the first and second heavy-component essential oils until the mixture is uniform, and use a glass bottle or a stainless steel tank to sub-pack the mixture. Pad a layer of non-woven fabric on the lid to ensure that the liquid in the tank can breathe.

[0050] S6 puts the mixture into a constant temperature incubator, sets the decomposition temperature at 36°C ± 1°C, and the decomposition time at 120 h to obtain the decomposed mixture.

[0051] S6 feeds the decomposed mixture into the distillation equipment, controls the heating temperature of the distiller at 98°C, the condensation temperature at 15°C, the evaporation flow rate at 5 L / h, and the distillation time at 1 h, collects the third heavy-component essential oil obtained by oil-water separation, and performs dehydration and filtration treatment on the third heavy-component essential oil to obtain the clean fourth heavy-component essential oil.

[0052] S7 mixes the obtained fourth heavy-component essential oil and the light-component pure essential oil obtained from step S3 to obtain the finished rose essential oil with qualified plasticizer indicators.

[0053] Comparative Example 1

[0054] Compared with Example 1, the rose essential oil is not subjected to the molecular distillation treatment in steps S2 and S3, and only the microbial decomposition and re-distillation treatment in steps S4 - S7 are carried out.

[0055] During the microbial decomposition process, the rose essential oil needs to be diluted and incubated at a constant temperature. The microorganisms need oxygen during the incubation process, the container cannot be sealed, and the decomposed mixture needs to be re-distilled and heated. This series of operations will damage and volatilize some aromatic components in the rose essential oil (especially the components in the light essential oil), reducing the appearance aroma and quality of the essential oil.

[0056] Therefore, only using microbial decomposition and re-distillation treatment is difficult to ensure the true aroma and quality of the finished rose essential oil.

[0057] Comparative Example 2

[0058] The present invention has conducted experiments on the single use of pyrolysis and molecular distillation to separate plasticizers.

[0059] Among them, pyrolysis has no obvious effect on reducing the plasticizers in rose essential oil.

[0060] When only molecular distillation is used to separate the plasticizers in the essential oil of aromatic plants, only a part of the light-component essential oil without plasticizers can be obtained, while a large amount of plasticizers are contained in the heavy-component essential oil, resulting in a low yield of qualified essential oil, and the value and output of the essential oil do not match.

[0061] Compared with Comparative Examples 1 and 2, in the present invention, the rose essential oil is first treated by molecular distillation, and the light-component essential oil of aromatic substances can be extracted and produced. The remaining heavy-component essential oil is mostly composed of wax alkanes, with extremely low fragrance and very few aromatic volatile components. Therefore, after a series of operations such as microbial decomposition and re-distillation treatment, the heavy components will not affect the aroma and component content of the essential oil. This shows the importance of the synergistic effect of molecular distillation treatment and microbial decomposition treatment in the present invention.

Claims

1. A process for treating aromatic plant essential oils by combining molecular distillation and microbial decomposition, characterized in that: The steps include: S1. Select aromatic plant essential oils that have been tested for excessive plasticizers such as DBP and DEHP; S2, feeding the aromatic plant essential oil into a molecular distillation device, and after molecular distillation treatment, obtaining a first heavy component essential oil and a light component primary essential oil; S3, the first light component primary essential oil is fed again into a molecular distillation device, and after molecular distillation treatment, a second heavy component essential oil and a light component pure essential oil are obtained; S4, mixing the first recombinant essential oil and the second recombinant essential oil, adding thereto a pure dew having a normal aroma and appearance but containing microorganisms and belonging to the same aromatic plant as the essential oil, and stirring thoroughly to obtain a mixed solution; S5, placing the mixed solution in a constant temperature incubator, and obtaining a mixed solution after the microorganisms have fully decomposed the plasticizer; S6, feeding the mixed solution after microbial decomposition into a distillation device, collecting the third heavy component essential oil obtained by oil-water separation after distillation, and dehydrating and filtering the third heavy component essential oil to obtain a fourth heavy component essential oil; S7, mixing the fourth heavy component essential oil obtained with the light component pure essential oil obtained in step S3 to obtain a finished aromatic plant essential oil product with a qualified plasticizer index.

2. The process for treating aromatic plant essential oils by combining molecular distillation and microbial decomposition according to claim 1, characterized in that: In step S2, the molecular distillation process parameters are as follows: The feed temperature is 35℃-40℃, the feed speed is 30-35rpm / min, the vacuum degree is 1-2mbar, the scraper speed is 260-280rpm / min, the heating evaporation temperature is 60-65℃, and the condensation temperature is 5-10℃.

3. The process for treating aromatic plant essential oil by combining molecular distillation and microbial decomposition according to claim 1, characterized in that: In step S3, the molecular distillation process parameters are as follows: The feed temperature is 35-40°C, the feed speed is 30-35rpm / min, the vacuum degree is 1-2mbar, the scraper speed is 220-230rpm / min, the heating evaporation temperature is 50-55°C, and the condensation temperature is 5-10°C.

4. The process for treating aromatic plant essential oil by combining molecular distillation and microbial decomposition according to claim 1, characterized in that: In step S4, the mass ratio of essential oil to hydrosol is 5:1000; the temperature of the hydrosol is 36°C±1°C.

5. The process for treating aromatic plant essential oil by combining molecular distillation and microbial decomposition according to claim 4, characterized in that: In step S4, the microorganisms in the hydrosol are Pseudomonas, Bacillus and Fusarium fujikura.

6. The process for treating aromatic plant essential oil by combining molecular distillation and microbial decomposition according to claim 1, characterized in that: In step S5, the decomposition temperature for the microorganisms to fully decompose the plasticizer is 36°C±1°C, and the decomposition time is 120 hours.

7. The process for treating aromatic plant essential oil by combining molecular distillation and microbial decomposition according to claim 1, characterized in that: In step S6, the process parameters of the distillation treatment are as follows: The heating temperature is 98°C, the condensing temperature is 15°C, the evaporation flow rate is 4-5L / h, and the distillation time is 1h.

8. The process for treating aromatic plant essential oil by combining molecular distillation and microbial decomposition according to claim 1, characterized in that: The aromatic plant essential oil is rose essential oil, the molecular weights of the components in the first heavy component essential oil, the second heavy component essential oil, the third heavy component essential oil and the fourth heavy component essential oil are all 240-400; the molecular weight of the components in the light component pure essential oil is 120-180.

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