Fragrance composition, preparation method and essence thereof

Abstract

The invention discloses a spice composition, a preparation method and essence thereof, and relates to the technical field of spices, and the preparation method comprises the following steps: mixing and crushing a first raw material and a second raw material to obtain a mixed raw material; wherein the polarity of a first target extract in the first raw material is different from that of a second target extract in the second raw material; inoculating a lactobacillus plantarum LP-01 strain liquid to the mixed raw material, performing pulse dynamic fermentation, and performing low-temperature refrigeration to obtain a mixture to be extracted; performing supercritical carbon dioxide dynamic gradient extraction on the to-be-extracted mixture to obtain the perfume composition; the perfume composition comprises a first target extract and a second target extract. Through cooperation of pulse dynamic fermentation and supercritical carbon dioxide dynamic gradient extraction, efficient and synchronous enrichment of the relative content of the first target extract and the second target extract is achieved, and the total extraction rate is effectively increased.

Description

Technical Field

[0001] This application relates to the field of fragrance technology, and in particular to fragrance compositions, preparation methods and fragrances thereof. Background Technology

[0002] In related technologies, when multiple plant materials are extracted simultaneously, it is usually impossible to extract target active ingredients of different polarities from multiple plant materials at the same time. This results in different target active ingredients increasing or decreasing in turn, leading to insufficient extraction and extremely low extraction rate (total extraction rate ≤2%). Consequently, the aroma may become monotonous. Summary of the Invention

[0003] The main purpose of this application is to provide a fragrance composition, preparation method and fragrance essence thereof, in order to solve the technical problems of insufficient extraction of plant complex aroma components and single aroma level in related technologies.

[0004] To achieve the above objectives, this application proposes a method for preparing a fragrance composition, the method comprising:

[0005] The first raw material and the second raw material are mixed and pulverized to obtain a mixed raw material; wherein, the first target extract in the raw material and the second target extract in the second raw material have different polarities;

[0006] After inoculating the mixed raw materials with Lactobacillus plantarum LP-01 inoculum, pulse dynamic fermentation was carried out, followed by low-temperature refrigeration to obtain the mixture to be extracted;

[0007] The mixture to be extracted is subjected to supercritical carbon dioxide dynamic gradient extraction to obtain the flavoring composition; wherein the flavoring composition includes the first target extract and the second target extract.

[0008] In one embodiment, the pulsed dynamic fermentation includes:

[0009] The inoculated mixed raw materials were subjected to the first stage of fermentation under microaerobic conditions;

[0010] After the first stage of fermentation is completed, the second stage of fermentation continues under pulsed oxygen supply conditions.

[0011] In one embodiment, during the second stage of fermentation, pulsed low-intensity ultrasound is periodically injected.

[0012] In one embodiment, during the low-temperature refrigeration process, the system continuously vibrates for a second preset duration at intervals of a first preset duration, wherein the first preset duration is longer than the second preset duration.

[0013] In one embodiment, before inoculating the *Lactobacillus plantarum* LP-01 inoculum, the preparation method further includes:

[0014] Spray peppermint hydrosol onto the mixed ingredients.

[0015] In one embodiment, the supercritical carbon dioxide dynamic gradient extraction of the mixture to be extracted includes:

[0016] The first stage of extraction is carried out under the conditions of first pressure, first temperature and first CO2 flow rate;

[0017] After the first stage of extraction is completed, the second stage of extraction continues under the conditions of a second pressure, a second temperature, and a second CO2 flow rate; wherein the first pressure is lower than the second pressure, the first temperature is lower than the second temperature, and the first CO2 flow rate is lower than the second CO2 flow rate.

[0018] In one embodiment, during the first stage extraction and the second stage extraction, molecular sieves are simultaneously filled into the extraction device; and / or

[0019] Following the supercritical carbon dioxide dynamic gradient extraction, the preparation method further includes:

[0020] Ultrafiltration is performed using a molecular membrane.

[0021] In one embodiment, the first ingredient is dried tangerine peel, and the second ingredient is mint.

[0022] In addition, to achieve the above objectives, this application also proposes a fragrance composition obtained by the preparation method of the fragrance composition described above.

[0023] In addition, to achieve the above objectives, this application also proposes a fragrance comprising the fragrance composition as described above, propylene glycol, and glycerin; wherein the volume ratio of the fragrance composition, the propylene glycol, and the glycerin is 0.1:1:1 to 1:5:5.

[0024] One or more technical solutions proposed in this application have at least the following technical effects:

[0025] This application utilizes the synergistic effect of the cell permeation effect of *Lactobacillus plantarum* LP-01 strain in pulsed dynamic fermentation with supercritical carbon dioxide dynamic gradient extraction. *Lactobacillus plantarum* LP-01 strain permeates the cells of both raw materials and penetrates their cell walls. This allows for the extraction of more of the first and second target extracts with different polarities during the dynamic gradient extraction process, achieving efficient and simultaneous enrichment of the relative contents of the first and second target extracts. This effectively improves the total extraction rate, overcoming the drawback of conventional supercritical carbon dioxide extraction, which can only extract one target extract, and avoiding the problem of a single aroma profile in the extract. Furthermore, this application uses low-temperature refrigeration of the mixed raw materials after pulsed dynamic fermentation to inhibit microbial metabolism and enzyme activity, thereby terminating the fermentation reaction and preventing over-fermentation from affecting the extraction rate and aroma of the two target extracts. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic flowchart of the preparation method of the fragrance composition of this application;

[0028] Figure 2 This is a schematic diagram of the supercritical carbon dioxide dynamic gradient extraction process in one embodiment;

[0029] Figure 3 These are GC-MS component analysis diagrams of Example 1 and Comparative Example 1 of this application.

[0030] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0032] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0033] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0034] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0035] In related technologies, there is a technical problem that fragrances extracted from a single plant material have a single aroma level. Therefore, the applicant selected another plant material, extracted the two materials separately and then blended them to solve the technical problem of the single aroma level of the fragrance. However, because one of the extracts obtained after extraction is highly polar and the other extract is fat-soluble, there is a technical problem that layering and aggregation are easy to occur when artificially or mechanically blending them. This leads to excessive fluctuations in the content of the components of the blended fragrance product, and the flavor is prone to the phenomenon of overly strong top notes and weak after notes, making it impossible to form a natural blended aroma delivery in the mixed extraction process.

[0036] Furthermore, to address the aforementioned technical issues, the applicant simultaneously extracts the two raw materials to avoid stratification and aggregation during subsequent compounding. However, simultaneous extraction still presents the following technical problems: it fails to extract the target active ingredients of different polarities from the two raw materials; simultaneously, it causes the two types of active ingredients to interact inversely, resulting in extremely low extraction rates (total extraction rate ≤ 2%), and still leads to a single aroma profile. Therefore, the main technical problems in the related technologies involving the simultaneous extraction of multiple plant raw materials are insufficient extraction and a single aroma profile.

[0037] Therefore, this application proposes a method for preparing a flavoring composition. By utilizing the cell permeation effect in pulsed dynamic fermentation and the synergistic effect of supercritical carbon dioxide dynamic gradient extraction, the relative content of two target extracts is efficiently and simultaneously enriched, so that the two target extracts are efficiently enriched and dissolved in the gradient extraction stage, thereby solving the technical problems of insufficient extraction and single aroma level.

[0038] Based on this, refer to Figure 1 , Figure 1 This is a schematic flowchart illustrating the preparation method of the fragrance composition of this application. The embodiments of this application propose a method for preparing a fragrance composition, the method comprising steps S100 to S300:

[0039] Step S100: The first raw material and the second raw material are mixed and pulverized to obtain a mixed raw material; wherein, the first target extract in the raw material and the second target extract in the second raw material have different polarities.

[0040] Based on subsequent steps S200 to S300, in this embodiment, the mass ratio of the first raw material to the second raw material is 1:0.2 to 1:5.

[0041] It should be noted that the first target extract in the feedstock and the second target extract in the second feedstock have different polarities. The polarity of the first target extract can be higher or lower than that of the second target extract. Because of this difference in polarity, during the subsequent supercritical carbon dioxide dynamic gradient extraction process, the two feedstocks mutually promote the dissolution of their effective components in the CO2 solvent. This co-solubility effect enhances the solubility of the solutes (first and second target extracts) during the supercritical carbon dioxide dynamic gradient extraction process, thereby altering the polar microenvironment of the supercritical fluid and successfully expanding the supercritical CO2 polarity window, further improving the extraction rates of both target extracts.

[0042] Specifically, both the first and second raw materials are plant-based. For example, in one instance, the first raw material is dried tangerine peel, and the second raw material is peppermint. Furthermore, to avoid the dilution of the aroma of the mixed raw materials due to the use of pure water in related technologies, in one embodiment, before inoculating with the *Lactobacillus plantarum* LP-01 inoculum, the preparation method further includes spraying peppermint hydrosol onto the mixed raw materials.

[0043] Specifically, peppermint hydrosol is sprayed onto the mixed raw materials to adjust the water content of the mixed raw materials to 18%–20%. In this embodiment, the use of peppermint hydrosol not only enhances the aroma intensity of the mixed raw materials and avoids diluting the aroma with water, but also prevents the aroma components from undergoing hydrolysis, which would otherwise weaken the aroma. In this example, the first and second raw materials can be pulverized to 20–40 mesh. In this example, the mass ratio of peppermint to dried tangerine peel can be 1:0.2 to 1:0.5.

[0044] Alternatively, in another example, the first ingredient is honeysuckle and the second ingredient is licorice.

[0045] Step S200: After inoculating the mixed raw materials with Lactobacillus plantarum LP-01 inoculum, pulse dynamic fermentation is carried out, and then the mixture to be extracted is obtained after low-temperature refrigeration.

[0046] It is understandable that the *Lactobacillus plantarum* LP-01 selected in this embodiment has strong compatibility with natural plant components and can secrete pectinase, cellulase, and hemicellulase. By decomposing the glycosidic bonds of pectin and cellulose in the two plant raw materials, it disrupts the dense structure of the two raw materials, making the main aroma components in the cells of the two raw materials easier to dissolve. In addition, the lactic acid produced by the metabolism of *Lactobacillus plantarum* LP-01 can lower the pH of the system, further softening the cell walls of the raw materials and creating conditions for the penetration of the solvent used in the subsequent dynamic gradient extraction.

[0047] Specifically, in one possible implementation, the inoculation amount of Lactobacillus plantarum LP-01 culture solution is 3% to 4% (v / w); that is, 3 to 4 ml of Lactobacillus plantarum LP-01 culture solution is inoculated per 100g of mixed raw materials.

[0048] In one possible implementation, the process for obtaining Lactobacillus plantarum LP-01 inoculum is as follows: Lactobacillus plantarum LP-01 freeze-dried bacterial powder is added to sterile water at 37°C to obtain a bacterial solution, which is then dissolved by shaking and glucose solution is added to obtain an activated bacterial solution; the activated bacterial solution is inoculated into MRS liquid culture medium and cultured at 37°C under anaerobic conditions for 24 hours.

[0049] In one possible implementation, 50 mL of sterile water is added to every 1 g of Lactobacillus plantarum LP-01 lyophilized bacterial powder; the amount of glucose solution used is 5 mL of glucose solution per 100 mL of bacterial culture; the MRS liquid medium is 500 mL MRS liquid medium, the components of which include 10 g / L peptone, 10 g / L beef extract, 5 g / L yeast extract, 20 g / L glucose and 80 mL / L Tween, and the pH is 6.2-6.4; the shaking speed during culture is 150 rpm.

[0050] In addition, this step involves pulsed dynamic fermentation of the mixed raw materials before supercritical carbon dioxide dynamic gradient extraction. Pulsed dynamic fermentation promotes the penetration of Lactobacillus plantarum LP-01 cells through the cell walls of both raw materials, releasing the precursors of the first and second target extracts. This preliminary enrichment of the first and second target extracts is achieved through cell permeation, providing favorable conditions for subsequent extraction of the target extracts and significantly enhancing the aroma of the flavor composition.

[0051] The temperature, pH, and oxygen concentration conditions can be the same or different at different stages of pulsed dynamic fermentation. In one embodiment, pulsed dynamic fermentation includes: the inoculated mixed raw materials undergoing a first-stage fermentation under microaerobic conditions; after the first-stage fermentation is completed, a second-stage fermentation continues under pulsed oxygen supply conditions.

[0052] It should be noted that the purpose of the first stage of fermentation is to allow the Lactobacillus plantarum LP-01 cells to penetrate the cells of the mixed raw materials; the purpose of the second stage of fermentation is to promote the penetration of the cells through the cell walls of the mixed raw materials.

[0053] In one example, to better achieve pulsed dynamic fermentation, the first stage of fermentation was carried out at a temperature of 30°C, a pH of 6.5, and a fermentation time of 24 hours, with a micro-aerobic condition of an oxygen concentration of 5%. The second stage of fermentation was carried out at a temperature of 37°C, a pH of 4.8, and a fermentation time of 36 hours, with a pulsed oxygen supply condition of an oxygen concentration of 0.8% ± 0.1%, pulsed once every 4 hours, and a single oxygen supply duration of 12 ± 2 seconds.

[0054] In addition, to better promote the penetration of the bacterial cells through the cell walls of the mixed raw materials, in one embodiment, pulsed low-intensity ultrasound is periodically injected during the second stage of fermentation.

[0055] Specifically, pulsed low-intensity ultrasound can be injected every 12 hours. The parameters for injecting pulsed low-intensity ultrasound are: 50W to 60W and 20kHz to 25kHz low-intensity ultrasound injected every 5 to 10 minutes. In one example, to better enable the bacteria to penetrate the cell walls of the mixed raw materials, 50W and 20kHz low-intensity ultrasound is injected every 5 minutes.

[0056] Additionally, it should be noted that the mixed raw materials after pulsed dynamic fermentation are subjected to low-temperature refrigeration to inhibit microbial metabolism and enzyme activity, thereby terminating the fermentation reaction and preventing over-fermentation from affecting the extraction rate and aroma of the final target extract. In one possible implementation, the low-temperature refrigeration temperature is 4°C, and the time is 12 hours.

[0057] Furthermore, in one embodiment, during the low-temperature refrigeration process, vibration is continuously performed for a second preset duration at intervals of a first preset duration, where the first preset duration is longer than the second preset duration. This intermittent and continuous vibration during low-temperature refrigeration ensures thorough mixing of the mixture to be extracted, promoting the redistribution of flavor compounds. In one example, vibration is performed for 5 minutes every 2 hours.

[0058] Step S300: Supercritical carbon dioxide dynamic gradient extraction is performed on the mixture to be extracted to obtain a fragrance composition; wherein the fragrance composition includes a first target extract and a second target extract.

[0059] In this embodiment, supercritical carbon dioxide dynamic gradient extraction is used to perform gradient extraction on different target extractants, with a total extraction time of 1 to 3 hours.

[0060] It should also be noted that the solvent used in the dynamic gradient extraction in this embodiment is CO2.

[0061] Furthermore, the conditions for supercritical carbon dioxide gradient extraction at different stages can be the same or different. For example, in one possible implementation, refer to... Figure 2 , Figure 2 This is a schematic diagram of a supercritical carbon dioxide dynamic gradient extraction process in one embodiment. The supercritical carbon dioxide dynamic gradient extraction of the mixture to be extracted includes:

[0062] Step S310: The first stage of extraction is carried out under the conditions of first pressure, first temperature and first CO2 flow rate.

[0063] Step S320: After the first stage extraction is completed, the second stage extraction continues under the conditions of the second pressure, the second temperature and the second CO2 flow rate; wherein the first pressure is less than the second pressure, the first temperature is less than the second temperature and the first CO2 flow rate is less than the second CO2 flow rate.

[0064] Specifically, since the first pressure is lower than the second pressure, the first temperature is lower than the second temperature, and the first CO2 flow rate is lower than the second CO2 flow rate, when the polarity of the first target extract is higher than that of the second target extract, the second target extract is extracted in the first stage of extraction, and the first target extract is extracted in the second stage of extraction; when the polarity of the first target extract is lower than that of the second target extract, the first target extract is extracted in the first stage of extraction, and the second target extract is extracted in the second stage of extraction.

[0065] Specifically, if the polarity of the first target extract is higher than that of the second target extract, then in the first stage of extraction, the microorganisms in the mixture to be extracted continue to completely penetrate the cells of the raw material and penetrate the cell wall of the raw material, thereby extracting more of the second target extract; then in the second stage of extraction, the microorganisms in the mixture to be extracted continue to completely penetrate the cells of the raw material and penetrate the cell wall of the raw material, thereby extracting more of the first target extract.

[0066] Additionally, during gradient switching—that is, after the first stage of extraction is completed and before the second stage of extraction begins—ethanol is added to the extraction apparatus as a polarity modifier to further increase the extraction rate. In one example, the polarity modifier is ethanol with a mass fraction of 90%–95%.

[0067] It should be noted that the specific pressure, temperature, and CO2 flow rate of the supercritical carbon dioxide dynamic gradient extraction need to be set according to the first and second target extracts. For example, the first stage of extraction is carried out under the conditions of a first pressure of 12 MPa to 18 MPa, a first temperature of 35°C to 40°C, and a first CO2 flow rate of 20 mL / min; after the first stage of extraction is completed, the second stage of extraction is carried out under the conditions of a second pressure of 25 MPa to 35 MPa, a second temperature of 45°C to 55°C, and a second CO2 flow rate of 28 mL / min.

[0068] Understandably, the extraction time varies at different stages. For example, in one instance where the first raw material is dried tangerine peel and the second raw material is peppermint, the extraction time for the first stage is 1.5 hours to extract low-polarity components such as limonene, hesperidin, α-pinene, and γ-terpinene from the dried tangerine peel. The target extract for the second stage is high-polarity components such as menthol and menthone from the peppermint, so its extraction time is 2.5 hours.

[0069] It is evident that during the supercritical carbon dioxide dynamic gradient extraction process, the bacterial cells in the mixture to be extracted continue to completely penetrate the cells of the raw material and penetrate the cell wall of the raw material. This allows the dynamic gradient extraction to extract more of the first and second target extracts with different polarities, thus overcoming the drawback of conventional supercritical carbon dioxide extraction, which can only extract one of the target extracts.

[0070] In one embodiment, molecular sieves are simultaneously filled into the extraction device during both the first-stage extraction and the second-stage extraction; and / or

[0071] Following supercritical carbon dioxide dynamic gradient extraction, the preparation method also includes:

[0072] Step S400: Ultrafiltration is performed using a molecular membrane.

[0073] Specifically, the molecular sieve is a type 4A molecular sieve; the molecular sieve packing amount is 15% to 25%; the extraction equipment can be an extraction vessel; specifically, the molecular cutoff of the molecular membrane is 1 kDa.

[0074] This embodiment uses molecular sieve purification and / or molecular membrane purification and enrichment to avoid the problem that residual waxes, pigments and other impurities in the target extract can seriously affect the transparency and taste of the flavoring when multiple plant materials are extracted at the same time.

[0075] It should be noted that in related technologies, molecular sieve purification is performed after extraction, which not only leads to some loss of the target extract during transfer but also requires additional steps such as column purification and solvent recovery. This embodiment performs molecular sieve purification simultaneously during supercritical carbon dioxide dynamic gradient extraction. This avoids the problem of high impurity residues in the target extract and, compared to related technologies, effectively reduces the loss of the target extract, eliminating the need for column purification and solvent recovery, thereby reducing energy consumption and costs.

[0076] Additionally, it should be noted that ultrafiltration using a molecular membrane can further enrich and purify the key aroma components in the target extract, thereby reducing the interference of impurities on the aroma of the target extract.

[0077] Furthermore, molecular sieve purification and molecular membrane purification enrichment are simultaneously employed to remove impurities such as pigments and waxes from the two target extracts, resulting in a fragrance composition without an irritating aftertaste. Compared to the version without molecular sieve purification and molecular membrane purification enrichment, the aroma intensity and persistence of the target extracts in this application embodiment are increased by 14.3% and 33.3%, respectively.

[0078] It is easy to see that, since the two target extractants in the initially enriched mixture have different polarities, this embodiment utilizes the cell permeation effect in step S200 in conjunction with the dynamic gradient extraction in that step. This achieves efficient and simultaneous enrichment of the relative contents of the first and second target extracts in this step, enabling efficient enrichment and dissolution of both extracts and overcoming the technical obstacle of the inverse relationship between the two target active extracts. Compared to conventional supercritical carbon dioxide extraction, this embodiment, through the synergy of pulsed dynamic fermentation and dynamic gradient extraction, increases the total extraction rate by 40%–60%, and the total enrichment of the first and second target extracts increases by ≥30%.

[0079] Furthermore, when the first raw material is dried tangerine peel and the second raw material is peppermint, the Lactobacillus plantarum LP-01 inoculum solution is inoculated into the dried tangerine peel-peppermint mixture and then subjected to dynamic fermentation. Lactobacillus plantarum LP-01 breaks down the glycosidic bonds of pectin and cellulose in the dried tangerine peel-peppermint mixture, thereby disrupting the dense structure of the mixture and making the main aroma components within the cells more easily dissolved. At the same time, the lactic acid produced by Lactobacillus plantarum LP-01 during fermentation can lower the pH of the system and further soften the cell walls of the dried tangerine peel-peppermint mixture, creating conditions for the penetration of the solvent used in the subsequent two-stage dynamic gradient extraction.

[0080] Additionally, it should be noted that during the two-stage supercritical carbon dioxide dynamic gradient extraction process, the volatile oil component of peppermint, one of the raw materials, acts as an endogenous entrainer. Specifically, due to the different polarities of the raw materials tangerine peel and peppermint, the two raw materials mutually promote the dissolution of their effective components in the solvent CO2. This co-solution effect is utilized to release terpenoids in the volatile oil of peppermint. These terpenoids enhance the solubility of the solutes (target extracts from tangerine peel and peppermint) during the two-stage gradient extraction process, thereby altering the polar microenvironment of the supercritical fluid and successfully expanding the polarity window of supercritical CO2, further improving the extraction rate of the two types of target extracts.

[0081] Specifically, after using peppermint and dried tangerine peel as raw materials, the first stage of extraction prioritizes the extraction of low-polarity components such as limonene, hesperidin, α-pinene, and γ-terpinene from the dried tangerine peel; the second stage mainly extracts high-polarity components such as menthol and menthone from the peppermint; among them, limonene and menthol are the main target extracts.

[0082] To better extract limonene from dried tangerine peel and menthol from peppermint, the extraction pressure was set to 15 MPa, the temperature to 38℃, and the CO2 flow rate to 20 mL / min during the first stage of extraction; the extraction pressure was set to 30 MPa, the temperature to 50℃, and the CO2 flow rate to 28 mL / min during the second stage of extraction.

[0083] It is understandable that, due to the preparation method provided in this application, the natural flavor and pharmacological activity of mint and dried tangerine peel can be fully preserved, resulting in a unique refreshing and sweet aftertaste in the obtained flavor composition. Specifically, limonene, hesperidin, and menthol form a citrus-cool complex aroma framework, while the woody notes of α-pinene and the herbal notes of menthone complement each other, making the overall aroma more layered, and the coolness and fruitiness are harmonious and natural. Compared with conventional supercritical carbon dioxide extraction, the preparation method provided in this application, through the synergistic effect of pulsed dynamic fermentation and dynamic gradient extraction, increases the final total extraction rate by 40% to 60%, while the enrichment of the main aroma components (limonene and menthol) increases by ≥30%.

[0084] In addition, to achieve the above objectives, this application also proposes a fragrance composition obtained by the above-described method for preparing fragrance compositions.

[0085] In addition, to achieve the above objectives, this application also proposes a fragrance comprising the fragrance composition as described above, propylene glycol, and glycerin; wherein the volume ratio of the fragrance composition, propylene glycol, and glycerin is 0.1:1:1 to 1:5:5.

[0086] Because the fragrance composition provided in this application has a layered aroma, the fragrance made from the fragrance composition has a rich aroma layer, which is sufficient to meet the customer's needs for aroma.

[0087] The technical features of the technical solution provided in this application will be described more clearly and completely below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application. Where specific technologies or conditions are not specified in the embodiments, they shall be performed in accordance with the technologies or conditions described in the literature in the art or in accordance with the product instructions. Reagents or instruments used without specified manufacturers are all conventional products that can be obtained commercially.

[0088] Example 1

[0089] Dried peppermint leaves and dried tangerine peel were mixed at a mass ratio of 1:0.5 and then pulverized to 20 mesh to obtain a mixed raw material. 1g of *Lactobacillus plantarum* LP-01 freeze-dried bacterial powder was added to 50mL of sterile water at 37℃ to obtain a bacterial solution. After shaking to dissolve the bacterial solution, 5% (w / v) glucose solution was added to obtain an activated bacterial solution. The activated bacterial solution was inoculated into 500mL of MRS liquid medium and cultured at 37℃ under anaerobic conditions for 24 hours to obtain *Lactobacillus plantarum* LP-01 inoculum. The shaking speed during culture was 150rpm. The MRS liquid medium consisted of 10g / L peptone, 10g / L beef extract, 5g / L yeast extract, 20g / L glucose, and 1mL / L Tween 80, with a pH of 6.2–6.4. It should be noted that *Lactobacillus plantarum* LP-01 was purchased from the China Industrial Microbial Culture Collection Center.

[0090] Peppermint hydrosol was sprayed onto the tangerine peel-peppermint mixture to adjust the water content of the mixture to 18%; Lactobacillus plantarum LP-01 inoculum was inoculated into the mixture after adjusting the water content at an inoculation rate of 3% (v / w).

[0091] The inoculated mixed raw materials were fermented for 24 hours at 30℃, pH 6.5, and oxygen concentration of 5% to allow *Lactobacillus plantarum* LP-01 cells to penetrate plant cells. Then, fermentation continued for 36 hours at 37℃, pH 4.8, and under pulsed oxygen supply conditions. The pulsed oxygen supply conditions were: pulsed once every 4 hours, oxygen concentration of 0.8%, and a single oxygen supply duration of 12 seconds. During the pulsed oxygen supply, 50W, 20kHz pulsed low-intensity ultrasound was injected every 12 hours for 5 minutes to promote *Lactobacillus plantarum* LP-01 cells to penetrate the raw material cell walls. After fermentation, the mixture was refrigerated at 4℃ for 12 hours, with vibration for 5 minutes every 2 hours during this period.

[0092] The mixture to be extracted was subjected to supercritical carbon dioxide dynamic gradient extraction to obtain the extract. In the first stage, the extraction vessel pressure was set at 15 MPa, the extraction temperature at 38℃, and the CO2 flow rate at 20 mL / min, and the extraction time was 1.5 hours. In this stage, low polar components such as limonene, hesperidin, α-pinene, and γ-terpinene from dried tangerine peel were preferentially extracted. In the second stage, the extraction vessel pressure was set at 30 MPa, the extraction temperature at 50℃, and the CO2 flow rate at 28 mL / min, and the extraction time was 2.5 hours. In this stage, high polar components such as menthol and menthone from peppermint were mainly extracted. During the supercritical carbon dioxide dynamic gradient extraction, the extraction vessel was simultaneously filled with 4A molecular sieves, with a filling amount of 25% of the total mass of dried peppermint leaves and dried tangerine peel.

[0093] The collected extract was subjected to ultrafiltration using a molecular membrane with a molecular cutoff of 1 kDa to obtain a fragrance composition. The fragrance composition includes target extracts from dried tangerine peel (limonene, hesperidin, α-pinene, and γ-terpinene; wherein limonene is the main aroma component) and target extracts from peppermint (menthol and menthone; wherein menthol is the main aroma component). The overall extraction rate of the preparation method in this embodiment is 3.5%.

[0094] The fragrance composition was diluted three times with ethanol and then analyzed by GC-MS. The results are shown below. Figure 3 , Figure 3 The images show the GC-MS component analysis of Example 1 and Comparative Example 1 of this application. GC-MS results show that the relative contents of the main components in the extract obtained in this example, namely menthol and limonene, are higher than those obtained by the conventional process (Comparative Example 1); specifically, compared with the conventional process (Comparative Example 1), the contents of the two main aroma components (menthol and limonene) in this example increased by ≥30%.

[0095] This embodiment also involves mixing the flavoring composition, propylene glycol, and glycerin in a volume ratio of 1:5:5 to prepare a flavoring. The flavoring prepared above was then subjected to sensory evaluation by a sensory evaluation team of 10 professionally trained and experienced personnel with strong judgment. The team members were familiar with various aroma characteristics and evaluation standards, and were able to provide accurate and objective evaluations of aroma changes before and after inhalation. The flavoring was scored across five dimensions: aroma intensity, aroma fullness, aroma persistence, comfort, and overall acceptability (0-5 points, 0.5-point intervals). The scoring results are shown in Table 1 below.

[0096] The experimental results in Table 1 show that the five aroma dimensions of the extract obtained by the preparation method of this application (Example 1) are higher than those of the traditional process (Comparative Example 1). The aroma fullness and persistence of the experimental group are improved by 33.3%, and the aroma harmony is also improved by 28.6% compared with the later mixing process (Comparative Example 2). The results of the verification of the raw material mixed extraction ratio (Comparative Example 3 and Comparative Example 4) showed that a low proportion of tangerine peel (Comparative Example 3) would lead to insufficient amount of one of the target extracts with different polarities during mixed extraction, thus failing to activate the co-solubility effect, resulting in a decrease in the total extraction rate (extraction rate of 1.8%). This, in turn, resulted in an excessively low content of the main component limonene, causing a severe loss of aroma across all dimensions and a 25% decrease in overall sensory acceptance. Under the condition of a high proportion of tangerine peel (Comparative Example 4), the total extraction rate also decreased (extraction rate of 2.1%). Excessive tangerine peel would adsorb peppermint volatile oil from supercritical CO2, and the high concentration of limonene would competitively occupy dissolution sites, reducing the dissolution rate of the main component menthol. This also damaged the aroma harmony and richness of the two aroma raw materials, resulting in a 12.5% ​​decrease in overall sensory acceptance.

[0097] Table 1. Comparison of sensory evaluation results of Example 1 and all comparative examples of flavorings.

[0098] Evaluation Dimensions / 5 points Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Aroma intensity 4.0 3.5 3.5 4.0 3.0 3.5 Aroma fullness 4.0 3.0 3.0 3.5 3.5 3.0 Fragrance persistence 4.0 3.5 3.0 3.5 3.0 3.0 Aroma Harmony 4.5 4.0 3.5 3.5 3.0 3.0 Overall acceptance 4.5 4.0 4.0 3.5 3.0 3.5

[0099] Example 2

[0100] The difference between this embodiment and Embodiment 1 is that in this embodiment, dried mint leaves and dried tangerine peel are mixed in a mass ratio of 1:0.2. The sensory evaluation results of the spices in this embodiment are as follows: aroma intensity 3.5 points, aroma fullness 3.0 points, aroma persistence 3.5 points, aroma harmony 4.0 points, and overall acceptability 4.0 points.

[0101] Comparative Example 1

[0102] Dried mint leaves and dried tangerine peel are mixed at a mass ratio of 1:0.5 and then pulverized to 20 mesh to obtain the mixed raw materials;

[0103] The mixed raw materials were subjected to conventional supercritical carbon dioxide extraction for 4 hours to obtain the extract. The parameters for conventional supercritical carbon dioxide extraction were set as follows: extraction vessel pressure of 25 MPa, extraction temperature of 45 °C, and CO2 flow rate of 25 mL / min.

[0104] The collected extract was diluted three times with ethanol, and the components were analyzed by GC-MS. The results are shown in [Figure number missing]. Figure 3 The total extraction rate of the comparative example preparation method was 2.3%, which shows that the total extraction rate was increased by 52.2% compared with Comparative Example 1.

[0105] The extract, propylene glycol, and glycerin were mixed in a volume ratio of 1:5:5 to prepare the fragrance. The prepared fragrance was then subjected to sensory evaluation by professionals, following the same evaluation procedure as in Example 1.

[0106] Comparative Example 2

[0107] Grind the dried mint leaves to 20 mesh and set aside; grind the dried tangerine peel to 20 mesh and set aside.

[0108] Crushed dried peppermint leaves and dried tangerine peel were subjected to conventional supercritical carbon dioxide extraction for 3 hours each, yielding peppermint extract and tangerine peel extract, respectively. The parameters for conventional supercritical carbon dioxide extraction of dried tangerine peel were set as follows: extraction vessel pressure of 20 MPa, extraction temperature of 40℃, and CO2 flow rate of 25 mL / min. The parameters for conventional supercritical carbon dioxide extraction of dried peppermint leaves were set as follows: extraction vessel pressure of 25 MPa, extraction temperature of 45℃, and CO2 flow rate of 25 mL / min.

[0109] The collected peppermint extract and tangerine peel extract were compounded at a volume ratio of 1:0.5. The compounded extract was then mixed with propylene glycol and glycerin at a volume ratio of 1:5:5 to obtain a flavoring. The flavoring was then subjected to sensory evaluation by professionals, and the evaluation process was the same as in Example 1.

[0110] Comparative Example 3 (the control group of Comparative Example 1)

[0111] The difference between this comparative example and Comparative Example 1 is that the mass ratio of dried peppermint leaves to dried tangerine peel in this comparative example is 1:0.1.

[0112] Comparative Example 4 (the control group of Comparative Example 1)

[0113] The difference between this comparative example and Comparative Example 1 is that the mass ratio of dried peppermint leaves to dried tangerine peel in this comparative example is 1:1.

[0114] The above description is only a part of the embodiments of this application and does not limit the scope of protection of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for preparing a fragrance composition, characterized in that, The preparation method includes: The first raw material and the second raw material are mixed and pulverized to obtain a mixed raw material; wherein, the first target extract in the first raw material and the second target extract in the second raw material have different polarities; After inoculating the mixed raw materials with Lactobacillus plantarum LP-01 inoculum, pulse dynamic fermentation was carried out, followed by low-temperature refrigeration to obtain the mixture to be extracted; The mixture to be extracted is subjected to supercritical carbon dioxide dynamic gradient extraction to obtain the flavoring composition; wherein the flavoring composition includes the first target extract and the second target extract.

2. The method for preparing the fragrance composition according to claim 1, characterized in that, The pulsed dynamic fermentation includes: The inoculated mixed raw materials were subjected to the first stage of fermentation under microaerobic conditions; After the first stage of fermentation is completed, the second stage of fermentation continues under pulsed oxygen supply conditions.

3. The method for preparing the fragrance composition according to claim 2, characterized in that, During the second stage of fermentation, pulsed low-intensity ultrasound is periodically injected.

4. The method for preparing the fragrance composition according to claim 1, characterized in that, During the low-temperature refrigeration process, the system continuously vibrates for a second preset duration at intervals of a first preset duration, where the first preset duration is longer than the second preset duration.

5. The method for preparing the fragrance composition according to claim 1, characterized in that, Before inoculating the *Lactobacillus plantarum* LP-01 inoculum solution, the preparation method further includes: Spray peppermint hydrosol onto the mixed ingredients.

6. The method for preparing the fragrance composition according to claim 1, characterized in that, The supercritical carbon dioxide dynamic gradient extraction of the mixture to be extracted includes: The first stage of extraction is carried out under the conditions of first pressure, first temperature and first CO2 flow rate; After the first stage of extraction is completed, the second stage of extraction continues under the conditions of a second pressure, a second temperature, and a second CO2 flow rate; wherein the first pressure is lower than the second pressure, the first temperature is lower than the second temperature, and the first CO2 flow rate is lower than the second CO2 flow rate.

7. The method for preparing the fragrance composition according to claim 6, characterized in that, During the first stage extraction and the second stage extraction, molecular sieves are simultaneously filled into the extraction equipment. and / or Following the supercritical carbon dioxide dynamic gradient extraction, the preparation method further includes: Ultrafiltration is performed using a molecular membrane.

8. The method for preparing the fragrance composition according to claim 1, characterized in that, The first ingredient is dried tangerine peel, and the second ingredient is mint.

9. A fragrance composition, characterized in that, The fragrance composition is obtained by the preparation method of the fragrance composition according to any one of claims 1-8.

10. A fragrance, characterized in that, The fragrance comprises the fragrance composition as described in claim 9, propylene glycol, and glycerin; wherein the volume ratio of the fragrance composition, the propylene glycol, and the glycerin is 0.1:1:1 to 1:5:5.

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