Preparation method of plum blossom and rhododendron flower composite extract for clothes fragrance

Abstract

This invention relates to the field of natural fragrance extraction technology, and discloses a method for preparing a compound extract of plum blossom and rhododendron for clothing fragrance. The method involves first extracting the fragrance from plum blossom and rhododendron separately using solvent-free vacuum extraction to collect the top notes. Then, the residue from the first extraction is subjected to low-temperature alcohol-water extraction, followed by resin fractionation elution, cation exchange resin and / or membrane separation to remove pigment impurities, nitrogen-containing irritating small molecules, and proteoglycan impurities. Finally, the top notes are reconstituted into the purified base fragrance extract to obtain a compound extract suitable for clothing fragrance products. This method helps retain floral fragrance activity, reduces color and irritation, and improves fabric compatibility.

Description

Technical Field

[0001] This invention relates to the field of natural fragrance extraction technology, and discloses a method for preparing a composite extract of plum blossom and rhododendron for clothing fragrance. Background Technology

[0002] With the development of products such as fabric fragrance sprays, fabric softeners, fragrance beads, and fabric care liquids, the market's requirements for natural floral fragrance raw materials are gradually increasing. Plant extracts used for fabric fragrances not only need to have good fragrance authenticity and complexity, but also need to take into account low color intensity, low irritation, and good compatibility with fabrics to avoid problems such as fragrance distortion, increased risk of coloring, or obvious irritating off-odors during use.

[0003] In existing technologies, floral fragrance extraction often focuses on a single flower or a single aroma component. For example, Chinese patent CN113403147A discloses a method for extracting and applying Rhododendron simsii essential oil. It uses the twigs and leaves of Rhododendron simsii as raw materials, obtains crude essential oil through water distillation, and then refines it through centrifugation, drying, aging, and molecular distillation to obtain Rhododendron simsii essential oil, which is then used in perfumes and cosmetic fragrances. This method can obtain essential oil raw materials with the characteristic aroma of rhododendron, but its raw material is a single rhododendron, and the process focuses on the acquisition and refinement of rhododendron essential oil. It does not design for the construction of complex aromas from multiple flower sources, nor does it selectively control pigment impurities, nitrogen-containing irritating components, and large molecular impurities for clothing fragrance applications.

[0004] In summary, existing technologies, when applied to clothing fragrances, still suffer from insufficient complexity of floral scents, high color intensity, difficulty in controlling irritating off-odors, and insufficient fabric compatibility. Therefore, it is necessary to provide a method for preparing a composite extract of plum blossoms and azaleas that combines low-temperature fragrance extraction, fragrance preservation, decolorization and purification, and reduction of irritation. Summary of the Invention

[0005] The technical objective of this invention is to provide a method for preparing a compound extract of plum blossom and rhododendron for clothing fragrance. While preserving the floral fragrance activity and compound aroma layers as much as possible, the method reduces the content of pigment impurities, irritating components and impurities that are not conducive to fabric application in the extract, thereby obtaining a natural compound extract with pure fragrance, low color intensity, low irritation and more suitable for clothing fragrance products.

[0006] To achieve the above-mentioned technical objectives, the present invention provides the following technical solutions.

[0007] In a first aspect, the present invention provides a method for preparing a composite extract of plum blossom and rhododendron for use in clothing fragrances, comprising the following steps:

[0008] S1. After pre-treating plum blossom petals and azalea petals under light-proof and low-temperature conditions, they were subjected to solvent-free vacuum extraction and condensation at 25-40℃ and -60--95kPa to obtain plum blossom top fragrance condensate, azalea top fragrance condensate and corresponding primary extraction residue, respectively.

[0009] S2. Mix the primary fragrance extraction residue of plum blossoms and the primary fragrance extraction residue of azaleas at a mass ratio of 1:(0.5-2), add 20-45 vol% ethanol aqueous solution, extract at 10-25℃, and separate the solid and liquid to obtain a secondary extract.

[0010] S3. The secondary extract is successively centrifuged and clarified, adsorbed by non-ionic macroporous adsorption resin, eluted with water and the water washing segment is discarded, then eluted with 10-30 vol% ethanol and the elution segment is discarded, and finally eluted with 40-65 vol% ethanol and the elution segment is collected; then the nitrogen-containing irritating small molecules and protein and polysaccharide macromolecules are removed by separation with cation exchange resin and / or membrane with a molecular weight cutoff of 1-5 kDa, and concentrated under reduced pressure at a temperature not exceeding 35°C to obtain purified base fragrance extract;

[0011] S4. The cold-cooled fractions of plum blossom top notes and rhododendron top notes are added back to the purified base fragrance extract to obtain a composite extract of plum blossom and rhododendron for clothing fragrance.

[0012] Preferably, the plum blossom is at least one of white plum blossom, pink plum blossom, or jade butterfly plum blossom; the azalea is the flower of azalea used for incense offering; both are selected from the flowers in their initial blooming stage, and the flower stalks, calyxes and stamens are removed, leaving only the petals as the extraction raw material.

[0013] Preferably, the pretreatment is to let it stand at 0-10°C for 2-8 hours under nitrogen protection.

[0014] Preferably, the solvent-free vacuum extraction conditions are: extraction temperature 28-35℃, vacuum degree -70-90kPa, extraction time 0.5-1.5h, and condensation temperature 0-5℃.

[0015] Preferably, the ratio of the primary aroma extraction residue to the ethanol aqueous solution is 1:6 to 12, and the extraction is performed 1 to 3 times, with each extraction lasting 0.5 to 2 hours.

[0016] Preferably, the ethanol-water solution is prepared using food-grade ethanol with a volume fraction of 25-35 vol%.

[0017] Preferably, the centrifugation clarification conditions are 3000-8000 rpm for 5-20 min, and the mixture is then pre-filtered through a microfiltration membrane with a pore size of 0.22-1 μm.

[0018] Preferably, the non-ionic macroporous adsorption resin is one or more of AB-8 resin, D101 resin, and HPD-100 resin; the loading flow rate is 1-3 BV / h, the water washing volume is 1-3 BV, the elution volume of 10-30 vol% ethanol is 1-3 BV, and the elution volume of 40-65 vol% ethanol is 1-5 BV.

[0019] Preferably, the cation exchange resin is a strong acid or weak acid cation exchange resin; when membrane separation is used, ultrafiltration membrane separation is preferred, with a molecular weight cutoff of 1 to 3 kDa.

[0020] Preferably, the free amino nitrogen content in the liquid obtained after step S3 is not higher than 0.05 wt%; the vacuum degree of the reduced pressure concentration is -0.06 to -0.095 MPa, and the residual ethanol content in the purified base fragrance extract after concentration is not higher than 1.0 wt%, and the solid content is 5 to 25 wt%.

[0021] Preferably, in step S4, the mass ratio of plum blossom top fragrance condensate, azalea top fragrance condensate, and purified base fragrance extract is (0.15-0.60):(0.10-0.45):1.

[0022] Preferably, the prepared composite extract has an absorbance of no more than 0.35 at 420 nm and an L* value of no less than 80 in the CIE Lab color space.

[0023] Secondly, the present invention also discloses the application of a composite extract of plum blossom and rhododendron obtained by the preparation method described in the first invention in the preparation of clothing fragrance products.

[0024] Compared with existing technologies, this invention, by separately collecting the top notes of plum blossoms and azaleas, performing low-temperature alcohol-water extraction on the primary fragrance extraction residue, and combining resin fractionation and elution, cation exchange resin and / or membrane separation purification before top note re-blending, can effectively reduce pigment impurities, nitrogen-containing irritating small molecules, proteins, polysaccharides and other undesirable components while better preserving the floral fragrance activity and complex aroma layers. As a result, the obtained complex extract has higher fragrance purity, lower overall color and irritation, and better fabric compatibility. When applied to clothing fragrance products, it can further exhibit better fragrance retention, fragrance naturalness and lower risk of staining on white or light-colored fabrics. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the preparation route of the plum blossom and rhododendron flower composite extract for clothing fragrance of the present invention.

[0026] Figure 2 This is a schematic diagram of the process of resin fractionation elution and de-irritant purification of the secondary extract in this invention. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention.

[0028] Unless otherwise stated, all percentages mentioned in this embodiment are mass percentages. "Low temperature" refers to a process temperature not exceeding 40°C. "Depressurization" generally refers to an operating environment with negative pressure relative to atmospheric pressure. "Recombination" refers to adding the top notes obtained in the previous stage back into the base fragrance extract obtained in the subsequent purification stage in a predetermined ratio to restore and rebuild the complete floral fragrance structure.

[0029] I. Terminology Explanation

[0030] To enable those skilled in the art to accurately understand the technical solution of this invention, the main terms involved in this invention are explained below:

[0031] 1. Top notes and condensation

[0032] This refers to the liquid phase component obtained by collecting plum blossom or azalea petals after condensation during solvent-free vacuum extraction, along with low-boiling-point volatile components. This component is enriched with volatile aroma-active substances that contribute significantly to the initial aroma perception.

[0033] 2. One-time aroma enhancement residue

[0034] This refers to the solid material remaining after the solvent-free, reduced-pressure aroma extraction of plum or azalea petals in step S1. Although some of the top notes are lost, this part still retains a large number of middle and base notes, as well as aroma precursors and mild aromatic components that can be dissolved in a low-temperature alcohol-water system.

[0035] 3. Purification of base fragrance extract

[0036] It refers to the light-colored, low-irritant extract with a predominantly mid-to-base aroma obtained by low-temperature extraction, solid-liquid separation, resin fractionation and elution, ion exchange and / or membrane separation, and low-temperature concentration of the primary aroma extraction residue. It is the main base of the compound extract in this invention.

[0037] 4. Water washing section

[0038] This refers to the initial effluent obtained after the secondary extract is loaded onto a non-ionic macroporous adsorption resin and eluted with pure water or deionized water. This portion mainly carries away some water-soluble sugars, inorganic salts, some protein degradation products, and other polar impurities.

[0039] 5. Low alcohol content

[0040] This refers to the fraction obtained by elution with a 10-30 vol% ethanol aqueous solution. This fraction is usually enriched with some weakly adsorbed impurities that can easily cause an increase in color or bring out a green, astringent, or rough odor, as well as some low-fragrance polar components.

[0041] 6. Mid-alcohol range

[0042] This refers to the target fraction obtained by elution with a 40-65 vol% ethanol aqueous solution. This fraction typically balances good retention of the main floral aroma components with low overall color and off-odor levels, and is the core aroma segment retained in this invention.

[0043] 7. Irritating small molecules

[0044] This refers to nitrogen-containing small molecules, some volatile amines, protein degradation products, and small polar components with sharp, unpleasant odors that may cause nasal irritation, astringent or irritating sensations, or discomfort when used on fabric surfaces in the extraction system of this invention.

[0045] 8. Fabric coloring risk

[0046] This refers to the risk that, when extracts are applied to systems such as fabric fragrance sprays, fabric softeners, and fabric care liquids, residual impurities such as pigments, polyphenols, and adhesives may cause white or light-colored fabrics to experience color shifts, yellowing, or an increase in overall color difference.

[0047] 9. Overall color, aroma and flavor score

[0048] This refers to the result obtained by trained evaluators who comprehensively score the samples from the perspectives of floral authenticity, fragrance purity, harmony between plum and azalea fragrance layers, naturalness, and user pleasure. The higher the score, the closer the fragrance is to the ideal floral scent for clothing.

[0049] 9. Fragrance release performance

[0050] This refers to the ability of an extract to release its fragrance again after being applied to a fabric and subjected to external forces such as wearing, folding, and friction. It is an important indicator for evaluating its continued performance in clothing applications.

[0051] II. Compound Extracts and Preparation Systems

[0052] (I) Composition of the compound extract

[0053] The plum blossom and azalea composite extract for clothing fragrance obtained by this invention can be understood in terms of its composition as a synergistic structure of three parts:

[0054] The first part is the cold condensation of plum blossom head fragrance;

[0055] The second part is the cold condensation of rhododendron flower heads;

[0056] The third part is the purified base fragrance extract.

[0057] The first two parts are mainly responsible for supplementing and restoring the freshness, exuberance, and initial recognition of the floral fragrance system; the third part is mainly responsible for providing the fragrance framework, roundness, adhesion, and compatibility with the clothing base system in the middle and base notes. By re-blending the first two parts into the third part, a more complete plum-rhododendron complex fragrance profile can be reconstructed without significantly increasing the color and irritation.

[0058] In a preferred embodiment, the mass ratio of plum blossom top notes, rhododendron top notes, and purified base fragrance extract can be controlled as (0.15–0.60):(0.10–0.45):1, preferably (0.25–0.40):(0.20–0.35):1. Below this range, the top notes are not fully recovered, and the fragrance appears dull and heavy; above this range, the initial aroma is too strong, the fragrance balance decreases, and it may cause the fragrance to dissipate quickly from the fabric surface.

[0059] (II) Preparation System

[0060] To enable those skilled in the art to implement this invention, a preparation system suitable for carrying out the method of this invention is now described. This preparation system may include:

[0061] 1. Raw material pretreatment unit

[0062] This unit is used to screen, remove impurities from, and allow to settle at low temperatures, under nitrogen protection, and quantitatively feed plum blossom and azalea petals. It may include a cleaning assembly, an air separation assembly, a low-temperature storage tank, and a weighing assembly.

[0063] 2. Solvent-free reduced pressure aroma enhancement unit

[0064] This unit is used for low-temperature, reduced-pressure fragrance extraction of plum blossom petals and azalea petals, respectively. It may include a sealed fragrance extraction jar, a vacuum pump, a jacketed temperature control device, a condenser, a condensate collection tank, and a vacuum pressure monitoring device.

[0065] 3. Low-temperature extraction unit

[0066] This unit is used for low-temperature alcohol-water extraction of a mixture of primary aroma extraction residues. It may include an extraction tank with a stirrer, a refrigerant circulation temperature control system, and an ethanol-water solution metering addition assembly.

[0067] 4. Solid-liquid separation unit

[0068] This unit is used to perform preliminary slag removal, centrifugal clarification, and microfiltration pretreatment of the extract. It may include a centrifuge, plate and frame filter or bag filter, microfiltration membrane module, etc.

[0069] 5. Resin-based graded purification unit

[0070] This unit is used to complete the loading, adsorption, water washing, low-alcohol elution, and medium-alcohol elution of the secondary extract onto a non-ionic macroporous adsorption resin. The unit may include a resin column, a metering pump, a solvent switching valve, and a fraction collector.

[0071] 6. De-irritation purification unit

[0072] This unit is used to remove nitrogen-containing irritating small molecules and proteoglycan macromolecules through membrane separation components such as cation exchange resins and / or ultrafiltration membranes and nanofiltration membranes. The unit may include an ion exchange column, membrane modules, a circulation pump, and online conductivity and pressure monitoring devices.

[0073] 7. Low-temperature concentration unit

[0074] This unit is used for vacuum concentration of the target fraction after further purification of the alcohol fraction, at a temperature not exceeding 35°C. It may include a rotary evaporator, a falling film evaporator, or a vacuum concentrator.

[0075] 8. Repackaging and Finished Product Storage Unit

[0076] This unit is used to add the cold-cold fractions of plum blossom and rhododendron flower top notes to the purified base fragrance extract and stir to homogenize. It may include a reconstitution tank, a low-shear stirrer, a nitrogen-sealing device, and a light-proof storage tank.

[0077] In a preferred embodiment, the above system preferably employs a closed conveying system, a low-temperature environment, nitrogen protection, and light-protected operation to minimize the oxidation and loss of aromatic active components.

[0078] The low-temperature depressurization aroma extraction, ethanol-water extraction, resin fractionation and elution, cation exchange, ultrafiltration and depressurization concentration methods used in this invention are all mature unit operations in the field.

[0079] III. Preparation route and key process control

[0080] (I) Overall preparation route

[0081] like Figure 1 As shown, the preparation route of the present invention includes four core steps, namely:

[0082] S1: Extract fragrance under reduced pressure without solvent, and collect the cold-cold fractions of plum blossom top notes and rhododendron top notes;

[0083] S2: After mixing the primary aroma extraction residue, perform low-temperature alcohol-water extraction to obtain a secondary extract;

[0084] S3: The secondary extract is subjected to fractional purification and low-temperature concentration to obtain purified base fragrance extract;

[0085] S4: The two top notes are condensed and separated and added back to the purified base fragrance extract to obtain the final compound extract.

[0086] The four steps mentioned above are not simply linked together, but rather follow an overall process logic of "preserving the top notes first, then extracting the base notes, then reducing color and irritation, and finally reconstructing the fragrance." The aim is to simultaneously solve the problems that are common in the application of traditional floral extracts in clothing fragrances, such as dull fragrance, dark color, high irritation, and insufficient fabric compatibility.

[0087] (II) Step S1: Solvent-free vacuum aroma extraction

[0088] The purpose of this step is to capture the most volatile components of plum blossoms and azaleas that contribute the most to the initial fragrance under the gentlest possible conditions.

[0089] In practice, it is preferable to first subject fresh petals to low-temperature settling and nitrogen protection. For example, fresh plum blossom petals and fresh azalea petals can be placed at 4°C for 2–8 hours to stabilize the surface free moisture and local respiration heat, reducing non-uniform volatilization in subsequent operations. Then, the two types of petals are separately placed in a solvent-free reduced-pressure aroma extraction unit and extracted for 0.5–1.5 hours at 25–40°C, preferably 28–35°C, and -60–-95 kPa, preferably -70–-90 kPa. No organic solvents are added during the aroma extraction process to avoid premature extraction of unnecessary pigments and impurities due to the premature introduction of highly polar solvents; simultaneously, the top notes are collected by condensation at 0–5°C.

[0090] After this step, three types of materials are obtained: first, plum blossom top notes condensed fraction; second, azalea top notes condensed fraction; and third, the corresponding primary fragrance extraction residue. Since the top notes condensed fraction is usually light-colored, low-viscosity, and rich in light volatile components, it should preferably be temporarily stored at low temperature, away from light, and nitrogen-sealed, and then reused in subsequent step S4.

[0091] (III) Step S2: After mixing the aroma extraction residue, perform low-temperature extraction.

[0092] The purpose of this step is to fully extract the middle and base notes and aroma precursors from the primary aroma extraction residue, while avoiding the use of high temperature and high alcohol content conditions that could lead to excessive extraction of pigments, polyphenols, colloids, and irritating impurities.

[0093] In this invention, the primary fragrance extraction residues of plum blossoms and azaleas are not simply extracted separately and then mixed. Instead, they are preferably mixed first at a mass ratio of 1:(0.5-2), more preferably 1:(0.8-1.2), and then a 20-45 vol% ethanol aqueous solution is added for extraction at 10-25°C. The preferred material-to-liquid ratio is 1:6-12. By using a medium-to-low concentration alcohol-water system and controlling the extraction temperature within a low range, it is beneficial to balance aroma extraction efficiency with impurity control.

[0094] In a preferred embodiment, a 25-35 vol% ethanol aqueous solution can be used for extraction 1-3 times at 15-20°C, each time for 0.5-2 hours. After extraction, solid-liquid separation is performed to obtain a secondary extract. In practice, it has been found that if ethanol of 50 vol% or higher or extraction at a temperature of 40°C or higher is used directly, although the extraction rate will increase, the overall color will be significantly darker, and pungent odors will accumulate more easily, which is detrimental to subsequent use in clothing fragrances.

[0095] (iv) Step S3: Staged purification and low-temperature concentration

[0096] This step is a crucial step in this invention that distinguishes it from traditional crude extraction processes of floral materials. Its goal is not simply to increase the extraction rate, but to retain the target fragrance components truly suitable for clothing fragrances through a process of segmentation, selection, and purification, while removing as many undesirable components as possible that are colored, astringent, or irritating.

[0097] The overall process of this step is as follows: Figure 2 As shown. First, the secondary extract is centrifuged for clarification, preferably at 3000–8000 rpm for 5–20 min. The supernatant after centrifugation is then microfiltered at 0.22–1 μm to remove suspended particles.

[0098] Next, the clarified liquid is introduced into a non-ionic macroporous adsorption resin column for fractional purification. One or more resins can be selected from AB-8, D101, and HPD-100. The preferred loading flow rate is 1–3 BV / h. After loading, the sample is first eluted with deionized water for 1–3 BV, discarding the water wash; then eluted with 10–30 vol% ethanol for 1–3 BV, discarding the low-ethanol fraction (the 10–30 vol% ethanol elution fraction); finally, eluted with 40–65 vol% ethanol for 1–5 BV, collecting the middle-ethanol fraction (the 40–65 vol% ethanol elution fraction). Through this fractional elution, pigments, polysaccharides, inorganic salts, low-aroma polar impurities, and components with astringent, green, or rough textures are more concentrated in the discarded fraction, while the fraction with higher aroma value and lower overall color intensity is collected as the target fraction.

[0099] Next, the collected alcohol fraction is further treated with cation exchange resin and / or membrane separation. The former is preferably used to remove volatile amines, free amino nitrogen, and some irritating nitrogen-containing small molecules; the latter is preferably used to remove proteins, polysaccharides, and high-molecular-weight colloidal impurities. Membrane separation can use an ultrafiltration membrane of 1–5 kDa, preferably 1–3 kDa. After the above treatment, the fraction typically exhibits characteristics such as reduced overall color, reduced turbidity, decreased irritation, and a clearer liquid.

[0100] Finally, the concentration is carried out under reduced pressure at a temperature not exceeding 35°C to achieve a suitable solids content. The preferred vacuum level is -0.06 to -0.095 MPa, and the solids content of the purified base fragrance extract after concentration is preferably 5 to 25 wt%. If the concentration temperature is too high, it will again cause the loss of top notes and some of the soft middle notes; therefore, the upper temperature limit should be strictly controlled.

[0101] (V) Step S4: Top notes are cooled and separated for blending

[0102] While step S3 retains a significant portion of the main middle and base notes, some loss of the lighter top notes is inevitable. Furthermore, the two top note condensates collected separately in step S1 are rich in active top note components. Therefore, by re-blending the plum blossom and azalea top note condensates in the purified base fragrance extract, a complex fragrance profile closer to the natural scent profile of fresh flowers can be reconstructed.

[0103] During implementation, it is preferable to slowly add the top notes (cold fraction) to the purified base fragrance extract at 10–20°C, and stir with low shear for 10–30 minutes to ensure uniform mixing of the three components. If necessary, the mixture can be allowed to mature under nitrogen for 12–24 hours to further refine the aroma structure. The final compound extract after reconstitution is typically a light yellow to nearly colorless transparent or semi-transparent liquid, with a good initial burst of aroma, a pleasant floral middle note, and good fabric retention.

[0104] IV. Mechanism of the preparation method of the present invention

[0105] The technical solution of this invention does not lie in simply using plum blossoms and azaleas as the two floral materials, but in constructing a targeted composite extraction route for clothing fragrance applications. Its mechanism can be understood from the following aspects:

[0106] 1. Collect the top incense first, then the base incense, to avoid the traditional drawback of "collecting first and then losing later".

[0107] Traditional methods of extracting floral materials by alcohol or water often involve a single extraction of all materials, followed by concentration and decolorization. A significant problem with this approach is that the lightest, most characteristic volatile components, which best represent the initial aroma of the flowers, easily escape during the later concentration and purification processes. Even with a high extraction rate, the fragrance often appears floral but lacks vibrancy. This invention avoids the problem of "overall extraction followed by overall loss" inherent in traditional methods by first collecting the top notes of plum blossoms and azaleas under low-temperature, reduced-pressure conditions, thus pre-selecting the most easily lost aromatic active substances before processing the middle and base notes in the residue.

[0108] 2. Mixing and extracting the residue from the first extraction process helps to synergistically build the middle and base notes.

[0109] This invention does not involve simply extracting and mixing plum and azalea residues separately, but rather preferably mixing the residues first and then performing a secondary extraction. The essence of this method is that the two floral materials form a relatively unified extraction medium environment during the low-temperature alcohol-water extraction process. The middle and base notes can be released, dissolved, and coordinated within the same system, thus mitigating the problems of fragrance separation, fragmented layers, and disjointedness that often occur when "extracting separately and then blending fragrances." For clothing fragrances, this integrative scent profile is particularly important because the fabric itself selectively absorbs fragrances; if the original fragrance profile has already separated, it is more likely to become unbalanced after being applied to the fabric.

[0110] 3. Selecting resin segments is more suitable for preserving aroma than cutting and bleaching in one go.

[0111] Traditional decolorization and purification methods often employ activated carbon, strong adsorption resins, or strong oxidation for overall decolorization. While this significantly reduces the overall color, it also easily adsorbs and destroys some target aromatic components, resulting in a thin, hollow, and dry aroma. This invention, through a tiered approach of "discarding in the water washing stage—discarding in the low-alcohol stage—retaining in the medium-alcohol stage," does not simply pursue decolorization. Instead, it uses differences in elution intensity to exclude high-color, high-impurity, and low-aroma fractions, while retaining the target fractions that contribute more to the overall color and aroma, thus achieving selective color reduction.

[0112] 4. Simultaneous control of nitrogenous irritants and proteoglycans reduces discomfort when using clothing.

[0113] For the application scenarios of clothing fragrances, this invention specifically considers the issues of nasal irritation, fabric residue, and yellowing of light-colored fabrics. Some nitrogen-containing small molecules, protein degradation products, and high-molecular-weight colloids in the secondary extract are often not the main fragrance components, but they can significantly increase the pungent smell, stickiness, and overall color difference. This invention removes some nitrogen-containing irritating components using cation exchange resin, and then removes large-molecular-weight colloidal impurities such as proteins and polysaccharides through ultrafiltration, thereby reducing irritation and the risk of fabric residue without significantly weakening the main floral fragrance.

[0114] 5. The top notes have been reconstituted to create a "top-middle-base" structure that is more suitable for clothing fragrances.

[0115] For fabric fragrance products, the ideal fragrance performance should not only be present upon spraying, but should also meet the following requirements: a distinct initial scent, a soft floral aroma that remains after settling, and the ability to release fragrance again after wearing or rubbing. This invention, by condensing and separating two top notes and re-blending them into a purified base fragrance extract, results in a final composite extract that retains both the freshness and vibrancy of the top notes and the smoothness and longevity of the base fragrance. This makes it more suitable for applications such as fabric sprays, fabric softeners, and fragrance beads that require a pleasant initial scent, lingering fragrance after settling, and fragrance release upon rubbing.

[0116] V. Testing and Evaluation Methods

[0117] To verify the feasibility and technical effectiveness of the process of this invention, this embodiment establishes two evaluation systems for the extract itself and its application in clothing fragrance.

[0118] (I) Ontological evaluation methods for extracts

[0119] 1. Extraction rate

[0120] The percentage of solids in the final compound extract relative to the total mass of the original flower petals is expressed as follows, calculated using the following formula:

[0121] Extraction rate (%) = (Mass of solids in the final compound extract / Total mass of original flower petals) × 100%

[0122] This indicator primarily reflects the material utilization efficiency of the process.

[0123] 2. Absorbance at 420nm (Comprehensive colorimetric index)

[0124] Prepare a test solution with a solid concentration of 1.0 wt% by taking the compound extract and measure the absorbance A420 at 420 nm. The lower the A420, the lighter the overall color, and the more suitable it is for fragrance application on white and light-colored clothing.

[0125] 3. Free amino nitrogen content

[0126] The concentration was determined using the ninhydrin colorimetric method and expressed as a percentage by mass. Lower levels of free amino nitrogen generally indicate fewer irritating nitrogenous molecules.

[0127] 4. Turbidity

[0128] Turbidity was measured using a turbidimeter and is expressed as NTU. The lower the turbidity, the fewer large particles or colloidal impurities are in the extract, and the more suitable the system is for subsequent formulation of products such as transparent fabric sprays.

[0129] 5. Retention index of characteristic volatile components

[0130] Headspace analysis of the samples was performed using HS-SPME-GC-MS. The response areas of six representative peaks contributing significantly to the overall color and aroma (defined as plum blossom characteristic peaks M1, M2, M3 and rhododendron characteristic peaks D1, D2, D3) were statistically analyzed. Using the sum of the overall color and aroma peak areas of the standard fresh petal samples as a reference, the relative retention percentage of the sum of the corresponding peak areas in the sample was calculated as the retention index of characteristic volatile components. A higher index indicates more complete retention of aroma activity.

[0131] 6. Overall color, aroma and flavor score

[0132] A blind evaluation was conducted by 12 trained evaluators, and the evaluation dimensions included:

[0133] (1) The authenticity of the floral fragrance;

[0134] (2) The harmony and integration of plum blossoms and azaleas;

[0135] (3) Aroma purity;

[0136] (4) Natural softness;

[0137] (5) The level of enjoyment in clothing scenes.

[0138] Each item is worth 10 points, and the weighted average is used as the overall color, aroma, and flavor score. The weights are 25%, 20%, 20%, 15%, and 20%, respectively.

[0139] 7. Stimulus rating

[0140] The samples were blind-evaluated by 12 trained evaluators using a 1-9 scoring system; 1 point indicates almost no irritation, while 9 points indicates significant irritation with a sharp, unpleasant odor. Lower scores were better.

[0141] (II) Evaluation Methods for the Application of Clothing Fragrance

[0142] To better reflect practical applications, each sample was further formulated into a standard fabric fragrance spray for testing. The standard spray matrix formulation is shown in Table 1.

[0143] Table 1 Standard Fabric Fragrance Spray Base Formulation

[0144]

[0145] The preparation method is as follows: First, add PEG-40 hydrogenated castor oil to a mixture of ethanol and dipropylene glycol and stir until homogeneous. Then, add the composite extract and mix well. Finally, add the aqueous phase, preservative and buffer system, filter and fill.

[0146] Samples for each embodiment and comparative example were prepared using the above-described spray matrix and tested on 100% pure cotton white cloth and polyester white cloth. The spraying amount was controlled at 0.20 g / 20cm×20cm cloth sample, and the samples were allowed to dry at room temperature for 30 min before evaluation.

[0147] 1. 24-hour fragrance longevity rating and 72-hour fragrance longevity rating

[0148] Evaluators smelled the fabric samples 24 hours and 72 hours after spraying, and scored them using a 1-9 point system, with higher scores indicating more pronounced fragrance retention.

[0149] 2. Aroma Release Scoring by Friction

[0150] The dried fabric sample was rubbed 20 times on a standard friction table, and then evaluated by an evaluator who smelled and scored it. The higher the score, the more obvious the aroma release after being subjected to external force.

[0151] 3. Color difference ΔE

[0152] The overall color difference of the white cloth before and after spraying was measured using a colorimeter. The smaller the ΔE, the lower the risk of fabric coloring.

[0153] 4. Overall Acceptability of Color and Aroma

[0154] Evaluators comprehensively assessed the overall pleasantness of the scent of the sprayed fabric sample in a clothing setting, using a 1-10 scoring system, with higher scores indicating greater suitability for clothing fragrance use.

[0155] The sample size for the above performance indicators is n=3, and the sample size for the scoring items is n=12. The mean plus the standard deviation is used.

[0156] VI. Examples and Comparative Examples

[0157] The following examples and comparative examples were conducted under the same batch of raw material conditions to minimize the impact of raw material differences. The raw materials used were early-blooming plum blossom petals and azalea petals, which were placed in a refrigerated environment within 2 hours of harvesting for later use.

[0158] 1. Example 1 (Preferred Example)

[0159] S1: Take 2.0 kg of fresh plum blossom petals and 2.0 kg of fresh azalea petals, and place them separately at 4℃ for 4 hours, while purging with nitrogen to create a low-oxygen protective environment. Then, place both into a solvent-free reduced-pressure aroma extraction unit and extract aroma for 50 minutes at 32℃ and -85 kPa, maintaining the condensation temperature at 2℃. 67 g of plum blossom top notes and 61 g of azalea top notes were obtained, along with corresponding primary aroma extraction residues.

[0160] S2: Mix the primary fragrance extraction residues of plum blossoms and azaleas at a mass ratio of 1:1, add 30 vol% ethanol aqueous solution (solid-liquid ratio 1:8), and extract twice at 18℃, 90 min each time. After extraction, filter and centrifuge to clarify at 6000 rpm for 10 min, then pre-filter through a 0.45 μm microfiltration membrane to obtain a clear secondary extract.

[0161] S3: The secondary extract was loaded into a D101 resin column at a flow rate of 2 BV / h. First, it was eluted with 2 BV of deionized water, and the water wash fraction was discarded. Then, it was eluted with 20 vol% ethanol for another 2 BV, and the low-alcohol fraction was discarded. Finally, it was eluted with 50 vol% ethanol for a total of 3 BV, and the middle-alcohol fraction was collected. The middle-alcohol fraction was further processed through a 732-type cation exchange resin column at a flow rate of 1.5 BV / h, followed by ultrafiltration through a 3 kDa membrane. The resulting liquid was concentrated under reduced pressure at 32°C and -0.085 MPa until the solids content was approximately 12 wt%, yielding the purified base fragrance extract.

[0162] S4: The cold fractions of plum blossom top notes, cold fractions of azalea top notes, and purified base fragrance extract were mixed at a mass ratio of 0.32:0.28:1. The mixture was stirred under low shear at 15℃ for 20 min and then nitrogen-sealed for 18 h to obtain a light yellow transparent composite extract.

[0163] 2. Example 2 (Low-limit window example)

[0164] 2.0 kg of plum blossom petals and 1.2 kg of azalea petals were collected and allowed to stand at 5℃ for 3 hours. The petals were then extracted at 30℃ and -78 kPa for 40 minutes each, with a condensation temperature of 4℃, yielding their respective top notes and primary extraction residues. The two primary extraction residues were mixed at a mass ratio of 1:0.6 and extracted twice at 15℃ for 60 minutes each time with a 25 vol% ethanol aqueous solution at a material-to-liquid ratio of 1:6. The extract was centrifuged, microfiltered, and loaded onto an AB-8 resin column. The water washing fraction and the 15 vol% ethanol fraction were discarded sequentially, and the 45 vol% ethanol fraction was collected. This was then treated with a cation exchange resin and concentrated under reduced pressure at 34℃. Finally, a compound extract was prepared by reconstitution at a ratio of plum blossom top note condensate: azalea top note condensate: purified base fragrance extract = 0.22:0.18:1.

[0165] 3. Example 3 (High Limit Window Example)

[0166] 2.2 kg of plum blossom petals and 2.6 kg of azalea petals were collected and allowed to stand at 4℃ for 6 hours. The petals were then extracted for 70 minutes at 35℃ and -88 kPa, respectively, with a condensation temperature of 1℃. The residues from the two primary extractions were mixed at a mass ratio of 1:1.3 and extracted twice at 20℃ for 120 minutes each time with a 35 vol% ethanol aqueous solution at a material-to-liquid ratio of 1:10. The extract was centrifuged, microfiltered, and loaded onto an HPD-100 resin column. The water washing fraction and the 25 vol% ethanol fraction were discarded sequentially, and the 60 vol% ethanol fraction was collected. This fraction was then treated with a 3 kDa ultrafiltration membrane and a cation exchange resin combination, and concentrated under reduced pressure at 30℃. Finally, a compound extract was prepared by reconstitution at a ratio of plum blossom topscent condensate: azalea topscent condensate: purified base fragrance extract = 0.38:0.33:1.

[0167] 4. Comparative Example 1 (without top note separation and recombination)

[0168] Except for step S1, the remaining steps are basically the same as in Example 1. That is, fresh plum blossom petals and azalea petals that have not undergone solvent-free vacuum extraction are directly mixed and extracted with a 30 vol% ethanol aqueous solution. After centrifugation, resin purification, cation exchange and ultrafiltration, the extract is concentrated and obtained without further top note condensation and re-dispensing.

[0169] 5. Comparative Example 2 (without resin fractionation and elution)

[0170] Steps S1 and S2 were performed according to Example 1, but in step S3, non-ionic macroporous resin fractionation and elution were not used. Instead, the secondary extract was centrifuged, microfiltered, and then directly concentrated under reduced pressure. The extract was then obtained by simple filtration and subsequently re-blended with top notes.

[0171] 6. Comparative Example 3 (without cation exchange and ultrafiltration)

[0172] Steps S1 and S2 and resin fractionation and elution were performed according to Example 1, but the middle alcohol fraction was not subjected to cation exchange and ultrafiltration treatment. Instead, it was directly concentrated under reduced pressure and then the top notes were recombined.

[0173] 7. Comparative Example 4 (the two residues were extracted separately and then directly mixed)

[0174] Step S1 is performed according to Example 1, but in step S2, the two primary fragrance extraction residues are not mixed first. Instead, they are extracted separately under the same conditions, and resin purification and concentration are completed separately. Finally, the two base fragrance extracts are simply mixed and the corresponding top fragrance condensate is added.

[0175] 8. Comparative Example 5 (High-Temperature Extraction Process)

[0176] Step S1 was performed according to Example 1, but in step S2, a 60 vol% ethanol aqueous solution was used to extract the mixture of the two primary aroma extraction residues once at 55°C. After resin purification, the mixture was directly concentrated and returned to the top fragrance cold fraction.

[0177] Table 2 Key process conditions for the examples and comparative examples

[0178]

[0179] VII. Performance Comparison and Result Analysis

[0180] (a) Properties of the extract

[0181] The performance of the extracts obtained in the examples and comparative examples was evaluated according to the aforementioned test methods, and the results are shown in Table 3.

[0182] Table 3 Comparison of Extract Performance

[0183]

[0184] As shown in Table 3, Examples 1-3 are significantly superior to the comparative examples in terms of overall color, irritation control, and retention of characteristic volatile components. Among them:

[0185] Compared with Comparative Example 1, the characteristic volatile component retention index of Examples 1-3 was significantly higher, indicating that the route of first separating the top notes and then re-blending has a significant effect on retaining the initial fragrance activity; Comparative Example 1, due to the lack of top note condensation and re-blending, had a significantly duller aroma performance and a significant decrease in the overall color and aroma score.

[0186] Compared to Comparative Example 2, the A420 in Examples 1-3 was significantly reduced, indicating that resin fractionation and elution is not an optional step, but a crucial step in reducing overall color and improving fabric compatibility. Although Comparative Example 2 had a relatively high extraction rate and acceptable retention of volatile components, its high overall color, high turbidity, and high irritation score are unfavorable for use in clothing fragrances.

[0187] Compared with Comparative Example 3, the free amino nitrogen content of Examples 1-3 was significantly lower and the irritation score was significantly reduced, indicating that the cation exchange and / or ultrafiltration steps did contribute to reducing irritating impurities.

[0188] Compared with Comparative Example 4, Examples 1-3 had higher overall color and aroma scores, indicating that "mixing the residues before extraction" is better than "extracting them separately and then simply blending them". Although the latter may seem to produce a complex system, the overall harmony and unity of the aroma are poor.

[0189] Compared with Comparative Example 5, Examples 1-3 are significantly better in terms of overall color, irritation, and retention of volatile components, indicating that the high-temperature, high-alcohol extraction route is not suitable for the target application of this invention.

[0190] (II) Performance of Clothing Fragrance Application

[0191] After the above samples were prepared into standard sprays as shown in Table 1, their application was evaluated on cotton and polyester fabrics, and the results are shown in Table 4.

[0192] Table 4 Comparison of the application performance of each sample in clothing fragrance spray

[0193]

[0194] As can be further seen from Table 4, the embodiments of the present invention not only have advantages at the level of the extract itself, but also demonstrate significant technical effects at the level of final clothing fragrance application:

[0195] Examples 1-3 all outperformed the comparative examples in terms of fragrance retention scores at 24h and 72h, indicating that the composite extract of the present invention not only has a more realistic initial scent, but also exhibits more stable performance on fabrics in the middle and later stages.

[0196] The high scores of frictional fragrance release in Examples 1-3 indicate that the top notes were not only applied at the moment of spraying, but also maintained good activity during the adsorption-release process of the fabric fibers.

[0197] Examples 1-3 all showed low ΔE values ​​on both cotton and polyester fabrics. In particular, the ΔE value of cotton fabric in Example 1 was only 0.78, and the ΔE value of polyester fabric was only 0.65. This indicates that the overall color is low, the risk of fabric coloring is small, and it is more suitable for white and light-colored clothing.

[0198] In terms of overall color and fragrance acceptance on the fabric, Example 1 showed the highest acceptance, reflecting that the present invention does not simply pursue fragrance concentration, but achieves a balance between authenticity, softness, purity and fabric compatibility.

[0199] (III) Comparison of characteristic peak responses

[0200] Regarding the retention index of characteristic volatile components, representative peaks of Example 1, Comparative Example 1 and Comparative Example 5 were compared using HS-SPME-GC-MS (normalized with internal standard peaks), and the results are shown in Table 5.

[0201] Table 5 Comparison of normalized response areas of representative characteristic peaks

[0202]

[0203] As shown in Table 5, Example 1 showed significantly higher peak responses than Comparative Example 1 and Comparative Example 5 across all six representative peaks, with a particularly noticeable improvement in peak response in the low retention time range. This indicates that the present invention, by separately capturing the top notes and then re-blending them in the later stages, can effectively retain the light aroma components that contribute significantly to the initial impression of fresh flowers. Comparative Example 1, lacking top note separation and re-blending, exhibited significantly lower peak responses. Although Comparative Example 5 contained some top notes, the high-temperature, high-alcohol extraction resulted in the loss of aroma-active components and the introduction of impurities, making its overall color and aroma significantly inferior to Example 1.

[0204] In summary, the technical route of this invention, namely "solvent-free vacuum extraction of aroma—low-temperature extraction of residue—resin fractionation and elution—de-irritant purification—top note re-blending," exhibits at least the following advantages:

[0205] (1) By separately capturing the cold condensate of the flower heads of plum blossoms and azaleas, the retention level of flower fragrance activity was improved;

[0206] (2) By mixing the fragrance residue after one extraction and then extracting, the overall harmony of the compound floral fragrance is improved;

[0207] (3) Resin grading and elution reduces the overall color and fabric staining risk;

[0208] (4) Irritation and turbidity are reduced through cation exchange and / or ultrafiltration;

[0209] (5) A floral fragrance structure with top notes, middle notes, and base notes more suitable for clothing scenarios was reconstructed through top note re-blending;

[0210] (6) In the final application of fabric spray, it showed good 24h / 72h fragrance retention, friction release and compatibility with light-colored fabrics.

[0211] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A method for preparing a clothes fragrance use Prunus mume and Rhododendron flower composite extract, characterized by, The method comprises the following steps: S1, the plum flower petals and the azalea flower petals are respectively pretreated under light-proof and low-temperature conditions, and then subjected to solvent-free reduced-pressure aroma extraction under the conditions of 25-40℃ and -60 to -95 kPa, and condensed and collected to obtain plum flower head fragrance condensate, azalea flower head fragrance condensate and corresponding first aroma extraction residues; S2, the plum flower first aroma extraction residue and the azalea flower first aroma extraction residue are mixed in a mass ratio of 1:(0.5-2), 20-45vol% ethanol aqueous solution is added, and leaching is carried out at 10-25℃, and solid-liquid separation is carried out to obtain secondary extraction liquid; S3, the secondary extraction liquid is sequentially subjected to centrifugal clarification, non-ionic macroporous adsorption resin adsorption, water elution and discarding of the water elution section, 10-30vol% ethanol elution and discarding of the elution section, and finally 40-65vol% ethanol elution and collection of the elution section; and then subjected to cation exchange resin and / or membrane separation with a molecular weight cut-off of 1-5kDa to remove nitrogen-containing irritating small molecules and protein and polysaccharide macromolecular impurities, and subjected to reduced-pressure concentration under the condition of not higher than 35℃ to obtain purified base incense extraction liquid; S4, the plum flower head fragrance condensate and the azalea flower head fragrance condensate are back-dosed into the purified base incense extraction liquid to obtain a plum flower and azalea flower compound extract for laundry fragrance.

2. The production method according to claim 1, characterized by, The plum flower is at least one of white plum flower, palace powder plum or jade butterfly plum; the azalea flower is incense azalea flower; both are selected from early-opening flowers, and the pedicels, calyces and stamens are removed, and only the petals are reserved as extraction raw materials.

3. The preparation method according to claim 1, characterized in that, In step S1, the pretreatment is: standing under the protection of nitrogen at 0-10℃ for 2-8h; and / or, the solvent-free reduced-pressure aroma extraction conditions are: aroma extraction temperature 28-35℃, vacuum degree -70 to -90kPa, aroma extraction time 0.5-1.5h, and condensation temperature 0-5℃.

4. The method of claim 1, wherein, In step S2, the solid-liquid ratio of the first aroma extraction residue to the ethanol aqueous solution is 1:6-12, leaching is carried out for 1-3 times, each time for 0.5-2h; and / or, the ethanol aqueous solution is prepared by using edible ethanol, and the volume fraction of ethanol is 25-35vol%.

5. The preparation method according to claim 1, characterized in that, In step S3, the centrifugal clarification conditions are 3000-8000rpm for 5-20min, and after centrifugation, pre-filtration is carried out through a microfiltration membrane with a pore size of 0.22-1μm.

6. The method of claim 1, wherein, In step S3, the non-ionic macroporous adsorption resin is one or more of AB-8 resin, D101 resin and HPD-100 resin; the loading flow rate is 1-3BV / h, the water washing volume is 1-3BV, the 10-30vol% ethanol elution volume is 1-3BV, the 40-65vol% ethanol elution volume is 1-5BV; and / or, the cation exchange resin is strong-acid or weak-acid cation exchange resin; when membrane separation is used, the membrane separation is preferably ultrafiltration membrane separation, and the molecular weight cut-off is 1-3kDa.

7. The preparation method according to claim 1, characterized in that, The free amino nitrogen content in the liquid obtained after step S3 is no higher than 0.05 wt%; the vacuum degree of the reduced pressure concentration is -0.06 to -0.095 MPa, and the residual ethanol content in the purified base fragrance extract after concentration is no higher than 1.0 wt%, and the solid content is 5 to 25 wt%.

8. The method of claim 1, wherein, In step S4, the mass ratio of the cold-cold fraction of plum blossom top notes, the cold-cold fraction of azalea top notes, and the purified base fragrance extract is (0.15-0.60):(0.10-0.45):

1.

9. The process according to any one of claims 1 to 8, characterized in that, The prepared composite extract has an absorbance of no more than 0.35 at 420 nm and an L* value of no less than 80 in the CIE Lab color space.

10. The application of the plum blossom and rhododendron compound extract prepared by the method of claim 9 in the preparation of clothing fragrance products.

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