An environmentally friendly air freshener composition based on natural extracts and a method of making the same

Abstract

The application discloses an environment-friendly perfume composition and a preparation method thereof. The composition is prepared from natural herb extracts and citrus-based natural essential oils by using a supercritical fluid extraction process. The fragrance components are derived from natural herb extracts of lavender, rosemary and mint, and orange and lemon grass essential oils. In order to ensure stability, natural emulsifiers, natural polysaccharide thickeners represented by plant lecithin, natural moisturizers and antioxidants are added in the formula, so as to further improve the storage stability of the product. The air freshener prepared by using the application not only has excellent fragrance effect and durability, but also is safe for human body and environment, and is a truly environment-friendly product.

Description

Technical Field

[0001] This invention relates to an environmentally friendly fragrance composition comprising natural herbal extracts and citrus essential oils, and its preparation method. Specifically, this environmentally friendly fragrance composition and its manufacturing method, through an optimal combination of natural herbal extracts and citrus essential oils obtained by supercritical fluid extraction, and a unique combination of natural emulsifiers and natural thickeners, exhibit excellent aroma effects and durability. Background Technology

[0002] Indoor air fresheners are typically manufactured primarily using artificial fragrances and organic solvents as their core ingredients. Undeniably, these traditional air fresheners have significant advantages in terms of strong fragrance and rapid effectiveness. However, with their widespread use, side effects such as allergic reactions and respiratory irritation caused by artificial fragrances have become increasingly apparent. Simultaneously, the use of volatile organic solvents continues to generate various environmental problems.

[0003] To address these shortcomings, researchers have developed air fresheners made from natural essential oils in recent years. However, due to the inherent characteristics of natural raw materials, these products have exhibited issues in practical use, such as poor fragrance longevity and low storage stability. Furthermore, the unstable emulsification state of natural essential oils leads to poor product uniformity, making it difficult to meet consumers' demands for high-quality air fresheners.

[0004] Previous documents

[0005] Patent documents

[0006] (Patent Document 1) Korean Patent Publication 10-2009-00563350

[0007] (Patent Document 2) Korean Patent No. 10-1999-0048841

[0008] (Patent Document 3) Korean Patent No. 10-1998-0075750

[0009] (Patent Document 4) Korean Patent No. 10-1996-0020678 Summary of the Invention

[0010] The primary objective of this invention is to effectively extract the active ingredients from natural herbs using supercritical fluid extraction technology, thereby improving the purity and stability of fragrance components.

[0011] Secondly, our goal is to prolong the fragrance's longevity through the optimal combination of natural herbal extracts and citrus essential oils.

[0012] Third, our goal is to ensure product stability and uniformity through the synergistic effect of natural emulsifiers (including plant lecithin) and natural polysaccharide thickeners.

[0013] Fourth, by combining natural moisturizers and natural antioxidants, we hope to improve the storage stability of the product.

[0014] The present invention solves the technical problem by adopting the following technical solution:

[0015] This invention relates to (a) a method for manufacturing an environmentally friendly air freshener, comprising the steps of preparing natural herbal extracts using supercritical fluids derived from one or more natural herbs selected from the group consisting of lavender, rosemary, and peppermint; (b) mixing the natural herbal extracts with citrus essential oils to prepare an herbal oil mixture; (c) preparing an emulsion by mixing purified water with a natural emulsifier containing plant lecithin; (d) dissolving a natural polysaccharide thickener in purified water to prepare a thickener solution; (e) mixing the herbal oil mixture, the emulsion, and the thickener solution to prepare a final composition; and (f) cooling and filtering the final composition; it includes a method for manufacturing an environmentally friendly air freshener.

[0016] At this point, the supercritical fluid is carbon dioxide, the citrus natural essential oil is one or more selected from the group consisting of orange essential oil and lemongrass essential oil, and the natural polysaccharide thickener is characterized by one or more selected from the group consisting of xanthan gum and sodium alginate.

[0017] In step (e), it is characterized by an additional mixture of one or more species selected from the group consisting of betaine and trehalose as natural moisturizers, and an additional mixture of one or more species selected from the group consisting of tocopherol and ascorbic acid as natural antioxidants. Based on 100 pounds of total herbal oil mixture, the natural herbal extract consists of 40-60 pounds of lavender extract, 20-40 pounds of rosemary extract, and 10-30 pounds of peppermint extract.

[0018] The citrus essential oil blend consists of 30-50 parts by weight of orange essential oil and 10-30 parts by weight of lemongrass essential oil. The emulsion is prepared by mixing plant lecithin and purified water. The thickener solution is characterized by dissolving a mixture of xanthan gum and sodium alginate in purified water. Based on a final component weight of 100 parts, the blend comprises 40-60 parts by weight of herbal oil mixture, 15-30 parts by weight of emulsion, 1-5 parts by weight of thickener solution, 3-7 parts by weight of natural moisturizer, 0.1-1.0 parts by weight of natural antioxidant, and the remainder of purified water.

[0019] The present invention has the following beneficial effects:

[0020] The environmentally friendly air freshener composition and its manufacturing method according to the present invention have the following advantages. First, the natural herbal extracts obtained by supercritical fluid extraction are safer and have higher purity than traditional solvent extraction methods, and there is no risk of residual solvent. Second, due to the optimal combination of natural herbal extracts and citrus essential oils, the evaporation rate of the fragrance is controlled, and the aromatic effect lasts for a long time. Third, due to the combination of natural emulsifiers and natural polysaccharide thickeners (including plant lecithin), the essential oils can be emulsified stably, resulting in excellent product uniformity. Fourth, the addition of natural moisturizers and natural antioxidants improves the oxidative stability of the natural ingredients, allowing for long-term storage. Fifth, all ingredients are composed of natural raw materials, resulting in an environmentally friendly product that is harmless to humans and the environment. Detailed Implementation

[0021] In the following descriptions of the specific structures or functions of the disclosed embodiments, the information is for illustrative purposes only and may be modified and performed in various forms. Therefore, the embodiments are not limited to the particular form of disclosure, and the scope of this specification includes changes, uniformities, or substitutions incorporated into the descriptive concepts.

[0022] Terms such as "first" or "second" can be used to describe various components, but the interpretation of these terms should only be used to distinguish one component from another. For example, the first component can be named the second component, and similarly, the second component can be named the first component. When a component is said to be "connected" to another component, it should be understood that it may be directly connected to or connected to another component, but there may be another component between them.

[0023] The terminology used in the embodiments is for illustrative purposes only and should not be construed as intended to be limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the presence of a feature, number, step, action, component, part, or combination thereof described in the specification, rather than one or more other features or numbers, steps, actions, or components, and should be understood to not exclude the possibility of the presence or addition of parts or combinations thereof.

[0024] Unless otherwise defined, all terms used herein, including technical or scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments pertain. Terms such as those defined in common dictionaries shall be interpreted as having the meaning consistent with their meaning in the relevant descriptive context and shall not be interpreted in an idealistic or overly formal sense unless expressly defined in this application.

[0025] This invention is intended to be practiced in many different forms and is not limited to the embodiments disclosed below, but is only intended to ensure that the disclosure of this invention is complete and to provide a complete introduction to those skilled in the art to which this invention pertains, and this invention should be defined only by the class of the claims.

[0026] In this embodiment of the invention, all terms used herein, including technical or scientific terms, unless otherwise defined, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms such as those defined in common dictionaries should be interpreted as having the meaning consistent with their meaning in the relevant descriptive context and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the embodiments of the invention.

[0027] In describing this invention, detailed descriptions should be omitted if it is determined that specific descriptions of related known descriptions may unnecessarily obscure the essential points of the invention. When using terms such as "comprising," "owning," and "manufacturing" as used in this specification, additional parts may be added unless "~only that" is used. In the case of a singular representation of an element, it includes multiple elements unless explicitly stated otherwise. When interpreting components, they are interpreted to include a margin of error, even if not explicitly stated otherwise.

[0028] Each feature in the various embodiments of the present invention can be combined with each other in part or in whole, and as those skilled in the art will fully understand, they can be technically linked and driven together, and each embodiment can be performed independently of each other or together in an associated relationship.

[0029] This invention relates to (a) a method for manufacturing an environmentally friendly air freshener, comprising the steps of preparing natural herbal extracts using supercritical fluids derived from one or more natural herbs selected from the group consisting of lavender, rosemary, and peppermint; (b) mixing the natural herbal extracts with citrus essential oils to prepare an herbal oil mixture; (c) preparing an emulsion by mixing purified water with a natural emulsifier containing plant lecithin; (d) dissolving a natural polysaccharide thickener in purified water to prepare a thickener solution; (e) mixing the herbal oil mixture, the emulsion, and the thickener solution to prepare a final composition; and (f) cooling and filtering the final composition; it includes a method for manufacturing an environmentally friendly air freshener.

[0030] At this point, the supercritical fluid is carbon dioxide, the citrus natural essential oil is one or more selected from the group consisting of orange essential oil and lemongrass essential oil, and the natural polysaccharide thickener is characterized by one or more selected from the group consisting of xanthan gum and sodium alginate.

[0031] In step (e), it is characterized by an additional mixture of one or more species selected from the group consisting of betaine and trehalose as natural moisturizers, and an additional mixture of one or more species selected from the group consisting of tocopherol and ascorbic acid as natural antioxidants. Based on 100 pounds of total herbal oil mixture, the natural herbal extract consists of 40-60 pounds of lavender extract, 20-40 pounds of rosemary extract, and 10-30 pounds of peppermint extract. The citrus essential oils consist of 30-50 wt% orange essential oil and 10-30 wt% lemongrass essential oil, and the emulsion is prepared by stirring plant lecithin and purified water. The thickener solution is characterized by dissolving a mixture of xanthan gum and sodium alginate in purified water.

[0032] At this point, the final ingredient is prepared based on 100 parts by weight of the herbal oil mixture, 40-60 parts by weight of the emulsion, 15-30 parts by weight of the thickener solution, 1-5 parts by weight of the natural moisturizer, 3-7 parts by weight of the natural antioxidant, 0.1-1.0 parts by weight of the natural antioxidant, and the remainder of purified water.

[0033] The reasons for selecting each raw material used in this invention and its technical significance are described in detail below.

[0034] Reasons for choosing natural herbal extracts

[0035] In this invention, lavender, rosemary, and peppermint are selected as the main natural herbs. Lavender consists of linalool and linalyl acetate, which are believed to have antibacterial, soothing, and aromatic properties. Rosemary contains 1,8-cineole, camphor, and α-pinene, which have antioxidant properties and a strong aromatic effect. Peppermint, with menthol and menthone as its main components, provides a refreshing scent and insect-repellent effect. The combination of these three herbs complements each other in terms of properties, producing an excellent aromatic effect.

[0036] Reasons for choosing natural citrus essential oil

[0037] Orange and lemongrass were chosen as citrus essential oils, each possessing unique technical properties. Orange essential oil is made from d-limonene, which acts as a natural solvent along with the fragrance. Lemongrass essential oil, with citral as its main component, has strong antibacterial properties and enhances the longevity of its aroma. When these essential oils are blended with herbal extracts, they exhibit synergistic aromatic effects, particularly because they evaporate at different rates, causing the aroma to evolve over time.

[0038] Reasons for choosing natural emulsifiers

[0039] In this invention, plant-based lecithin is selected as the primary natural emulsifier. Lecithin is a phospholipid, an amphiphilic substance possessing both hydrophilic and lipophilic components. Due to these properties, it forms a stable emulsion film at the interface between the aqueous and oil phases, thereby improving the dispersion stability of the essential oil. In particular, plant-based lecithin exhibits high biocompatibility, thus lacking magnetic polarity on the skin, and as a natural emulsifier, it helps maintain the product's environmental friendliness.

[0040] Reasons for choosing natural polysaccharide thickeners

[0041] The natural polysaccharide thickener system composed of xanthan gum and sodium alginate has the following technical significance: Xanthan gum maintains stable viscosity over a wide pH range and improves product usability through its shear resistance. Sodium alginate has excellent water retention, which can improve the moisturizing performance of the product, and regulates the release rate of essential oils due to its synergistic effect with xanthan gum. This dual thickener system simultaneously improves the physical properties and stability of the product.

[0042] Reasons for choosing a natural moisturizing cream

[0043] The natural moisturizing system, composed of 60% betaine and trehalose, is complementary in its properties. Betaine has osmotic regulation capabilities to maintain moisture balance, while trehalose has antioxidant activity and water-retaining effects. This combination of ingredients helps improve the product's moisturizing effect and the stability of other natural components.

[0044] Why Choose Natural Antioxidants?

[0045] The natural antioxidant system composed of tocopherol and ascorbic acid exhibits antioxidant activity through different mechanisms. Tocopherol is a fat-soluble antioxidant that prevents the oxidation of essential oils, while ascorbic acid is a water-soluble antioxidant that improves oxidative stability in water. Furthermore, ascorbic acid promotes the regeneration of tocopherol, thereby sustaining its antioxidant effect. In this way, each raw material selected in this invention exhibits a synergistic effect, maximizing product performance through complementary interactions with its respective functions. The key significance of the component ranges and process steps of this invention is described in detail below.

[0046] [The Key Significance of Component Scope]

[0047] 1. Content range of natural herbal extracts

[0048] In this invention, limiting the total amount of natural herbal extracts to the range of 40-60 g / L is of significant technical importance. If less than 40 g / L, the aromatic effect is insufficient; if more than 60 g / L, the balance with other components is disrupted, reducing product stability. Furthermore, the proportions of each herbal extract (lavender 45-55 g: rosemary 25-35 g: peppermint 15-25 g) are set to optimize the harmony and longevity of the fragrance.

[0049] 2. Content range of citrus essential oil

[0050] The total amount of citrus essential oil should be limited to 15-30g by weight, and the ratio of orange essential oil to lemongrass essential oil should be set at 30-50:10-30, as this range achieves optimal synergy with the herbal extracts. This ratio is important for optimizing the balance between the initial scent and reverberation.

[0051] 3. Content range of natural emulsifier system

[0052] The content of plant lecithin is limited to 4-5 g / L by weight, as this range achieves stable emulsification of the essential oil while maintaining the appropriate viscosity of the product. At lower amounts, emulsification stability is insufficient, and at higher amounts, product usability decreases.

[0053] 4. Content range of natural polysaccharide thickeners

[0054] The total amount of xanthan gum and sodium alginate is limited to 1-5 by weight, with the ratio set at 55-65:35-45, because the optimal viscosity and release rate of the essential oil can be controlled under these conditions.

[0055] [The Key Significance of Process Steps]

[0056] 1. Supercritical fluid extraction step

[0057] In the extraction process using supercritical carbon dioxide, the pressure is set to 300-350 bar and the temperature to 45-50°C for the following reasons: Under these conditions, the active ingredients of the herbs are selectively extracted, and the denaturation of aromatic components, especially those that are heat-sensitive, is minimized. Furthermore, this condition optimizes extraction yield and energy efficiency.

[0058] 2. Preparation steps of the herb oil mixture

[0059] The mixing temperature for herbal extracts and essential oils is set to 45-50°C, and the mixture is stirred at 200-300 rpm. This ensures a uniform mix between the two ingredients while minimizing the loss of volatile components.

[0060] 3. Emulsion preparation steps

[0061] When preparing the emulsion, homogenization at a temperature of 2,000-3,000°C and 50-55 rpm is chosen because this range allows for both fine granulation and stable emulsification of the essential oils. At lower conditions, emulsification is incomplete, while at higher conditions, denaturation of the composition becomes a problem.

[0062] 4. Thickener solution preparation stage

[0063] Dissolving the thickener in purified water at 60-65°C ensures optimized hydration and viscosity expression of the polysaccharide within this temperature range. A stirring speed of 400-600 rpm is optimal to prevent thickener aggregation while also preventing molecular weight loss due to excessive shear force.

[0064] 5. Final mixing stage

[0065] In the final mixing stage, a temperature of 55-60°C and a stirring time of 2-3 hours are the minimum conditions required for homogeneous mixing and stable components. During this process, an appropriate stirring speed of 300-400 rpm ensures uniform dispersion of the components while minimizing air ingress.

[0066] 6. Cooling and Filtration Stage

[0067] The final product is slowly cooled to 2-2°C at a rate of 25-30°C / min to prevent phase separation due to sudden temperature changes. Filtration using a membrane filter with a pore size of 0.2-0.45 μm is optimal for ensuring the product's microbiological stability while minimizing the loss of active ingredients. The process conditions at each stage are interrelated and play a crucial role in optimizing the overall quality and reliability of the product.

[0068] 1. Characteristics and quality standards of raw materials

[0069] The natural herbs used in this invention must meet the following quality standards to achieve optimal efficacy: Lavender is harvested during its flowering period, and rosemary leaves contain at least 1.5% essential oil. Peppermint preferably has a menthol content of at least 30%.

[0070] Citrus essential oils should be cold-pressed, especially orange essential oil, which is extracted from fresh orange peel. Lemongrass essential oil can be extracted through steam distillation.

[0071] 2. Detailed description of the manufacturing process

[0072] (1) Supercritical extraction process

[0073] The supercritical extraction device is equipped with an extraction tank of 1L or more. Before extraction, the herbal raw materials are pulverized to below 5mm. The pressure inside the extraction tank is gradually increased to reach the target pressure. After extraction, the decompression rate is adjusted to prevent extract loss.

[0074] (2) Preparation of herb oil mixture

[0075] The mixing of herbal extracts and essential oils is best done under vacuum stirring. This is to prevent oxidation during the mixing process and to minimize the loss of volatile components. Using a stirrer equipped with an anchor impeller is effective.

[0076] (3) Emulsion preparation

[0077] When preparing the emulsion, a high-speed homogenizer is used, and a two-step process of first homogenization followed by a second homogenization is preferred. The plant lecithin is dissolved beforehand by heating to 40-45°C. A jacketed container is used to control the temperature rise caused by heat generated during homogenization.

[0078] 3. Quality Control Methods

[0079] (1) Evaluation of physicochemical properties

[0080] -Particle size distribution: Measured using a laser diffraction particle size analyzer.

[0081] - Viscosity: Measured using a Brookfield viscometer at 25°C.

[0082] - pH value: Measured using a pH meter at 25°C.

[0083] - Emulsion stability: 3 months at 25°C and 40°C

[0084] (2) Evaluation of directional characteristics

[0085] - Initial Fragrance: The intensity and characteristics of the fragrance immediately after manufacturing.

[0086] - Reverberation longevity: The fragrance is still present after 24 hours.

[0087] -Odor Overview: How the nature of odor changes over time

[0088] 4. Storage and Usage Conditions

[0089] The product should be stored in a sealed container at a temperature of 15-25℃, away from direct sunlight. It is best used within 3 months of opening, and should be shaken gently before use.

[0090]

reflect

[0091] Through embodiments and comparative examples of the present invention, we will explain in detail the impact of the content of each component and manufacturing conditions on the characteristics of the final product.

[0092]

Composition of the Embodiments and Comparative Examples

[0093] [Table 1]

[0094] Composition and Comparative Examples of the Embodiments (Unit: Weight)

[0095]

[0096]

[0097] [Preparation Method of the Examples]

[0098] According to the manufacturing method of the present invention, the preparation examples 1-3 are as follows.

[0099] (1) Supercritical extraction conditions: 300-350 bar, 45-50℃

[0100] (2) Herbal oil mixture: 45-50℃

[0101] (3) Emulsion preparation: 50-55℃

[0102] (4) Thickener solubility: 60-65℃

[0103] (5) Final mixing: Stir at 55-60℃ for a period of time.

[0104] (6) Cooling filtration: 25-30℃ μm filter

[0105] [Manufacturing method of the comparative example]

[0106] Comparative Example 1: Using ethanol extraction (70% ethanol, 60°C for time) instead of supercritical extraction. Comparative Example 2: Emulsifier and thickener content settings are outside the acceptable range.

[0107] Comparative Example 3: Setting the content of herbal extracts and essential oils beyond the acceptable range.

[0108] [Test Examples and Evaluation Results]

[0109] [Table 2]

[0110] Product Feature Evaluation Results

[0111]

[0112] [Results Analysis]

[0113] 1. Features and advantages of Examples 1-3

[0114] The components of Examples 1-3 were all within appropriate ranges, exhibiting a uniform particle size distribution of 0.2-0.4 μm and a sufficient viscosity of 350-450 cPs. In particular, the aroma persisted for 22-26 hours, and no phase separation or discoloration was observed even after a 3-month storage stability assessment.

[0115] 2. Analyze the problems in the comparative examples.

[0116] Comparative Example 1 (Differences in extraction methods):

[0117] - Ethanol extraction increased the particle size to 2.1 μm.

[0118] - Viscosity loss due to residual solvent (200 cPs)

[0119] - Fragrance lasting time is significantly shortened to 8 hours.

[0120] Phase separation occurred 3 months later.

[0121] Comparative Example 2 (Excessive Emulsifier / Thickener):

[0122] - Loss of usability due to excessively high viscosity (800 cPs)

[0123] - Loss of stability due to increased pH (6.8)

[0124] gelling occurred after 3 months.

[0125] Comparative Example 3 (herb oil ratio or higher):

[0126] - Insufficient particle size distribution (0.8μm)

[0127] - Imbalance in olfactory harmony

[0128] -The initial taste was too strong

[0129] The results of this evaluation confirm that the content range of the components and manufacturing conditions proposed in this invention are crucial for optimizing product quality and stability. In particular, the use of supercritical fluid extraction and appropriate formulation of emulsifiers / thickeners have proven to be important factors determining product performance.

[0130] [Preparation and Evaluation of Implementation Examples and Comparative Examples]

[0131] The following experiments were conducted to manufacture an environmentally friendly air freshener composition using the natural extracts of the present invention and to confirm its properties. First, Examples 1 to 3 of the present invention were prepared, and Comparative Examples 1 to 3 were prepared for comparison with the examples.

[0132] Example 1 uses 50 weights of lavender extract, 30 weights of rosemary extract, and 20 weights of peppermint extract as natural herbal extracts, and 40 weights of orange essential oil and 20 weights of lemongrass essential oil as citrus essential oils. Plant lecithin (4.5g) and chitosan (1.2g) are used as natural emulsifiers, and xanthan gum (0.6g) and sodium alginate (0.4g) are used as natural polysaccharide thickeners. Additionally, betaine (3.5g) and trehalose (1.8g) are used as natural moisturizers, tocopherol (0.4g) and ascorbic acid (0.15g) are used as natural antioxidants, and purified water is used as a residue.

[0133] Examples 2 and 3 were prepared by varying the content of each ingredient within the range suggested by the present invention. In Example 2, the content of lavender extract was reduced to 45g by weight, the content of rosemary extract was reduced to 35g by weight, the content of orange essential oil was increased to 45g by weight, and the content of lemongrass essential oil was reduced to 15g by weight. In Example 3, conversely, the content of lavender extract was increased to 55g by weight, the content of rosemary extract was reduced to 25g by weight, the content of orange essential oil was reduced to 35g by weight, and the content of lemongrass essential oil was increased to 25g by weight.

[0134] In Comparative Example 1, 70% ethanol was used as the solvent instead of the supercritical extraction process of the present invention, and extraction was performed at 60°C for 4 hours. This was to determine the effect of the difference in extraction method on the characteristics of the final product. In Comparative Example 2, the contents of emulsifier and thickener were set outside the ranges recommended by the present invention, with plant lecithin increased to 8.0 by weight, chitosan increased to 3.0 by weight, xanthan gum increased to 1.5 by weight, and sodium alginate increased to 1.0 by weight. In Comparative Example 3, the contents of herbal extracts and essential oils were set outside the range of the present invention.

[0135] The particle size, viscosity, pH value, aroma persistence, and emulsion stability of the prepared examples and comparative examples were evaluated. Particle size was measured using a laser diffraction particle size analyzer, and viscosity was measured using a Brookfield viscometer at 25°C. pH value was measured using a pH meter at 25°C. Odor persistence was assessed over 24 hours, and emulsion stability was observed for 3 months at 25°C and 40°C.

[0136] The evaluation results showed that Example 1 exhibited physical properties of 0.3 μm particle size, 400 cPs viscosity, and pH 6.0, and demonstrated excellent 24-hour aroma retention and stable emulsification for 3 months. Examples 2 and 3 also showed similar superior performance. On the other hand, Comparative Example 1 increased the particle size to 2.1 μm, decreased the viscosity to 200 cPs, and significantly reduced flavor persistence to 8 hours due to ethanol extraction. Furthermore, phase separation occurred after 3 months. Comparative Example 2 showed an increase in viscosity to 800 cPs and a pH of 6.8, and gelation occurred after 3 months due to excessive use of emulsifiers and thickeners. Comparative Example 3 showed an increase in particle size to 0.8 μm due to an unsuitable ratio of herbal extracts and essential oils, and an unbalanced aroma harmony.

[0137] The results of these evaluations confirm that the content range and manufacturing conditions of each component proposed in this invention are crucial for optimizing the quality and stability of the final product. In particular, the use of supercritical fluid extraction showed significant improvements in particle size and flavor persistence, and appropriate formulation of emulsifiers and thickeners played a vital role in ensuring the long-term stability of the product.

[0138]

Experimental Example

[0139] The following experiments were conducted to demonstrate the properties and effects of the environmentally friendly air freshener composition using the natural extracts of the present invention.

[0140] [Experimental Example 1] Evaluation of Particle Size Distribution and Stability

[0141] Measuring instrument: Malvern Particle Size Analyzer 3000 (Malvern Instruments, UK)

[0142] Measurement conditions: 25℃ dispersion medium - pure water

[0143] Measurement time: immediately after manufacturing, 1 month, 2 months, 3 months

[0144] Measure the particle size distribution of each sample and observe its change over time. Evaluate the particle size based on the D50 value (median particle size) and calculate the distribution map as the Span value [(D90-D10) / D50].

[0145] [Table 3]

[0146] Particle size changes over time

[0147]

[0148] [Experimental Example 2] Evaluation of Emulsion Stability

[0149] Centrifugation conditions: 3,000 rpm, 30 minutes

[0150] Observation conditions: 25℃ and 40℃ respectively.

[0151] Evaluation timeframes: Immediately after manufacturing, 1 week, 1 month, 3 months

[0152] Emulsion stability was assessed by analyzing the separation rate (%) after centrifugation and particle morphology under a microscope.

[0153] [Table 4]

[0154] Emulsification stability under temperature conditions

[0155]

[0156]

[0157] [Experimental Example 3] Evaluation of the release behavior of aromatic components

[0158] Instrument: GC-MS (Agilent 7890B)

[0159] Chromatographic column: DB-5MS (30m × 0.25mm × 0.25μm)

[0160] Testing conditions: 50℃ (2 minutes) → 10℃ / min → 280℃ (5 minutes)

[0161] The emission behavior of major aromatic components was assessed by headspace measurements.

[0162] [Table 5]

[0163] Residual percentage of key components over time (%)

[0164]

[0165] [Experimental Example 4] Evaluation of antioxidant activity

[0166] To evaluate the antioxidant activity of the compositions of the present invention, the DPPH radical scavenging capacity, ABTS radical scavenging capacity, and total polyphenol content were measured.

[0167] (1) Determination of DPPH free radical scavenging ability

[0168] The sample was diluted with methanol and mixed with 0.2 mM DPPH solution at a 1:1 ratio, and then reacted at room temperature for 30 minutes. The absorbance was measured at 517 nm to calculate the free radical scavenging activity.

[0169] [Table 6]

[0170] DPPH free radical scavenging activity (IC50, μg / mL)

[0171] Sample classification IC50 value Positive control (vitamin C) Example 1 45.2 38.5 Example 2 48.7 38.5 Example 3 42.8 38.5 Comparison Example 1 95.4 38.5

[0172] (2) Determination of ABTS free radical scavenging ability

[0173] After generating ABTS radicals by mixing 7 mM ABTS with 2.45 mM potassium persulfate, the absorbance at 734 nm was adjusted to 0.70 ± 0.02. The sample and ABTS solution were mixed in a 1:1 ratio and reacted for 6 minutes, after which the absorbance was measured.

[0174] [Table 7]

[0175] ABTS free radical scavenger activity (%)

[0176]

[0177] (3) Determination of total polyphenol content

[0178] Total polyphenols were determined using the Folin-Ciocalteu reagent. A calibration curve was constructed using gallic acid as a standard, and the results are expressed as GAE (gallic acid equivalent).

[0179] [Table 8]

[0180] Total polyphenol content (mg GAE / g)

[0181] Sample classification Polyphenol content Example 1 185.4 Example 2 178.9 Example 3 192.3 Comparison Example 1 95.7

[0182] [Example 5] Microbial stability evaluation

[0183] (1) Provocation test (USP standard)

[0184] According to USP <51> The antimicrobial efficacy test method involved inoculating the following microorganisms and evaluating their preservation for 28 days.

[0185] - Staphylococcus aureus ATCC 6538

[0186] - Escherichia coli ATCC 8739

[0187] - Pseudomonas aeruginosa ATCC 9027

[0188] Candida albicans ATCC 10231

[0189] - Aspergillus brasiliensis ATCC 16404

[0190] [Table 9]

[0191] Challenge test results (Log reduction)

[0192]

[0193] (2) Preservation test based on pH value change

[0194] Microbial counts were measured over 28 days at pH 4.0, 5.5, and 7.0.

[0195] [Example 6] Skin irritation assessment

[0196] (1) 3D artificial skin model (EPISKIN) TM test

[0197] The assessment was conducted according to OECD TG 439 guidelines. Cell viability was measured by MTT assay 15 minutes after sample treatment.

[0198] [Table 10]

[0199] 3D artificial skin model test results (cell survival rate, %)

[0200] Sample classification Survival rate judgment Example 1 92.5 Non-irritating Example 2 91.8 Non-irritating Example 3 93.2 Non-irritating Positive control 35.4 Stimulate

[0201] [Example 7] Analysis of Volatile Organic Compounds (VOCs)

[0202] The impact on indoor air quality was assessed according to the EPA TO-15 method. Samples were collected using 6L containers and analyzed by GC / MS.

[0203] [Table 11]

[0204] Volatile organic compound emissions (μg / m³) 3 )

[0205]

[0206] [Experimental Example 8] Evaluation of the diffusion characteristics of fragrance components

[0207] (1) Diffusion distance measurement

[0208] The diffusion distance of fragrance components was measured using an electronic olfactory sensor within a 30-cubic-meter enclosed space. The evaluation was conducted under conditions of 25°C and 50% humidity.

[0209] [Table 12]

[0210] Fragrance diffusion distance changes over time (m)

[0211] Time elapsed Example 1 Example 2 Example 3 30 minutes 2.5 2.3 2.6 1 hour 3.8 3.5 3.9 2 hours 4.5 4.2 4.6 4 hours 4.8 4.5 4.9

[0212] The results of the above-mentioned additional experiments confirm that the composition of the present invention possesses excellent antioxidant activity and microbial stability, is non-irritating to the skin, and is harmless to the environment. Furthermore, the fragrance component exhibits excellent diffusion properties, demonstrating its suitability as an indoor air freshener. These additional experiments are believed to provide more objective evidence of the safety and effectiveness of the invented product.

[0213] [Results and Discussion]

[0214] The evaluation results of the examples and comparative examples of the environmentally friendly air freshener compositions using natural extracts proposed in this invention were analyzed, and the following technical significance was derived.

[0215] 1. The influence of supercritical fluid extraction process

[0216] In Examples 1-3, where supercritical extraction was used, the particle size of the herbal extracts was very uniform in the range of 0.2-0.4 μm. This is attributed to the fact that supercritical carbon dioxide penetrated into the micropores of the herbal tissues and effectively extracted the active ingredients. On the other hand, in Comparative Example 1, where ethanol extraction was performed, the particle size increased significantly to 2.1 μm. This was explained by the fact that ethanol has lower solvent permeability compared to supercritical carbon dioxide, resulting in incomplete extraction.

[0217] Of particular note is the difference in aroma persistence. Examples 1-3 showed excellent aroma persistence of 22-26 hours, while Comparative Example 1 showed a significantly reduced persistence of 8 hours. This is attributed to the fact that the supercritical extraction process can completely extract the volatile aromatic components of the herb without denaturation. Furthermore, in the case of ethanol extraction, problems with degradation of the original aroma due to residual solvents were also found.

[0218] 2. Optimization effect of the emulsification system

[0219] The combination of plant lecithin (4.0-5.0 g / w) and chitosan (1.0-1.5 g / w) used in Examples 1-3 formed a stable emulsion system. The viscosities of these embodiments were in the range of 350-450 cPs, and no phase separation occurred during a 3-month storage test. This is attributed to the synergistic effect between the amphiphilic effect of lecithin and the interfacial stabilizing effect of chitosan.

[0220] On the other hand, if the emulsifier content is excessive (lecithin 8.0 g / L, chitosan 3.0 g / L), as shown in Comparative Example 2, the viscosity increases to 800 cPs, usability decreases, and gelation occurs after 3 months. It is determined that excessive emulsifier leads to excessive formation of micelle structures, resulting in system instability.

[0221] 3. The role of the thickening system

[0222] The dual thickener system of xanthan gum and sodium alginate plays a crucial role in the physical properties and stability of the product. In Examples 1-3, the thickener ratios used (xanthan gum: sodium alginate = 0.5-0.7: 0.3-0.5 by weight) demonstrate its ability to regulate essential oil release while providing appropriate viscosity. In particular, the shear pull of xanthan gum and the water retention of sodium alginate are determined to complement each other, thereby improving product usability.

[0223] 4. Combination of herbal extracts and essential oils

[0224] The proportions of herbal extracts and essential oils used in Examples 1-3 showed optimized results in terms of fragrance harmony and longevity. In particular, the combination of lavender extract (45-55g by weight) as the main component and rosemary extract (25-35g by weight) and peppermint extract (15-25g by weight) as auxiliary components effectively created a layered fragrance.

[0225] The combination of 311 orange essential oil (35-45 parts by weight) and lemongrass essential oil (15-25 parts by weight) successfully achieved an initial refreshing aroma and a lasting aftertaste. On the other hand, when these proportions deviated, as shown in Comparative Example 3, it was confirmed that the aroma expression was disproportionate and sensory satisfaction decreased.

[0226] 5. Product stabilization mechanism

[0227] The excellent long-term stability of Examples 1-3 is attributed to the following complex factors. First, the uniform particle size distribution produced by supercritical extraction enhances the thermodynamic stability of the system. Second, the optimized emulsifier system effectively reduces the interfacial tension between the oil chamber and the water surface, preventing phase separation. Third, the dual thickener system enhances the physical stability of the product.

[0228] Of particular note is the maintenance of stable pH conditions within a range of 5.5–6.5. This is believed to have a positive impact not only on the chemical stability of the product but also on its microbiological stability. Furthermore, the antioxidant system of tocopherol and ascorbic acid effectively prevents the oxidation of the natural ingredients, minimizing quality degradation even during long-term storage.

[0229] In summary, the results confirm that the composition proposed in this invention is an optimized system that satisfies both product stability and usability while maximizing the properties of natural raw materials.

[0230] 6. Characteristics and significance of antioxidant activity

[0231] The compositions of the present invention exhibited IC50 values ​​of 42.8-48.7 μg / mL in evaluating DPPH free radical scavenging ability, demonstrating excellent antioxidant activity close to that of the positive control vitamin C (38.5 μg / mL). In particular, in the case of Example 3, the IC50 value was 42.8 μg / mL, which showed the best activity, and this was determined to be due to the highest content of lavender extract at 55 μg / mL.

[0232] It was also found that the free radical scavenging activity of the mediator was concentration-dependent. At a concentration of 200 μg / mL, Examples 1-3 showed a high scavenging capacity of 82.8-87.1%, while Comparative Example 1 showed only 48.2%. This demonstrates that the supercritical extraction process effectively extracts the antioxidant components of the herbal medicine.

[0233] As for the measurement results of total polyphenol content, Examples 1-3 showed high contents of 178.9-192.3 mg GAE / g. This is approximately twice that of Comparative Example 1 (95.7 mg GAE / g) extracted with ethanol, which again demonstrates the superiority of supercritical fluid extraction.

[0234] 7. Ensure microbial stability

[0235] As a result of the challenge test, Example 1 demonstrated excellent microbial control, meeting all the criteria for a “unique selling claim.” After 14 days, bacteria decreased by more than 3 logs and fungi decreased by 2 logs, with these effects lasting up to 28 days. This means that the natural preservation system of the inventive composition is functioning effectively.

[0236] Of particular note is its stability under pH variations. Stable microbial control was maintained within a pH range of 4.0–7.0, which is attributed to the synergistic effect of the natural antibacterial properties of lemongrass essential oil and the preservative effect of chitosan.

[0237] 8. Skin safety verification

[0238] When assessing skin irritation using a 3D artificial skin model, Examples 1-3 showed a high cell survival rate of over 90% and were deemed non-irritating. This was attributed to the invention's composition of all ingredients derived from natural raw materials, particularly the use of skin-friendly plant lecithin as an emulsifier.

[0239] 9. Environmental Safety Demonstration

[0240] As a result of the volatile organic compound (VOC) analysis, no harmful VOCs such as benzene, toluene, and xylene were detected in Examples 1-3. This result proves that the invention is a truly environmentally friendly product. Of particular note is that the risk of residual solvents has been completely eliminated by using a supercritical fluid extraction process.

[0241] 10. Optimize fragrance diffusion characteristics

[0242] As a result of the fragrance diffusion experiment in an indoor space, the composition of the present invention showed a diffusion distance of approximately 4.5-4.9 m after 4 hours. In particular, Example 3 showed an optimal diffusion distance of 4.9 m, which was attributed to the staged release of fragrance components due to the optimized mixing ratio of herbal extracts and essential oils. This fragrance diffusion characteristic remained stable even under certain temperature and humidity conditions, indicating that the dual thickener system effectively controlled the release of fragrance components.

[0243] Based on the results of the additional experiments described above, the composition of the present invention has been demonstrated to possess excellent antioxidant activity and microbial stability, and is also a product with proven skin and environmental safety. Furthermore, its fragrance diffusion properties have been optimized, and it has been proven to function excellently as an indoor air freshener.

Claims

1. An environmentally friendly air freshener composition based on natural extracts and its manufacturing method, characterized in that, The manufacturing method first uses supercritical fluid technology to select one or more natural herbs from a group of natural herbs, such as lavender, rosemary, and peppermint, to prepare natural herbal extracts. Then, the natural herbal extracts are mixed with citrus natural essential oils to obtain a herbal oil mixture. At the same time, purified water is mixed with a natural emulsifier containing plant lecithin to prepare an emulsion, and a natural polysaccharide thickener is dissolved in purified water to prepare a thickener solution. Then, the herbal oil mixture, emulsion, and thickener solution are mixed to obtain the final composition. Finally, the final composition is cooled and filtered to complete the manufacturing of the environmentally friendly air freshener.

Images