Preparation method of rose extract and application thereof

Abstract

The application discloses a preparation method and application of rose extract, and the rose petal is used as raw material, and the method comprises the following steps: (1) pretreatment; (2) water treatment; (3) fractional extraction; (4) separation and purification; (5) membrane treatment; (6) sterilization; (7) freeze-drying; (8) mixing and packaging. The application combines the rose petal with the low-temperature process, does not need to add the solubilizing material and the drying agent, can efficiently retain, directionally enrich the core aromatic substances in the rose petal and maintain the stability of active ingredients, the extract powder has good solubility and pure flavor, is suitable for the field of high-quality instant rose solid beverage and other healthy food fields, and is also suitable for the field of natural food preservative or antibacterial agent and the like.

Description

Technical Field

[0001] This invention relates to the field of plant extraction technology, and in particular to a method for preparing rose extract and its application. Background Technology

[0002] Roses, belonging to the genus Rosa of the Rosaceae family, are rich in various aromatic substances such as alcohols, phenols, and terpenes. Currently, traditional rose extract processing mainly employs high-temperature thermal extraction, evaporation concentration, and spray drying processes. Prolonged high-temperature treatment can easily cause the oxidation and decomposition of heat-sensitive aromatic substances (such as citronellol and phenylethyl alcohol) in roses and the loss of active ingredients, leading to flavor degradation and quality decline in the extract. This makes it difficult to meet the production requirements of high-quality instant solid beverages and other health foods for the flavor and functionality of rose raw materials. Summary of the Invention

[0003] This invention provides a method for preparing an extract that retains the active ingredients and flavor of rose aromatic substances, and explores its applications.

[0004] A method for preparing rose extract, using rose petals as raw material, includes the following steps: (1) Pretreatment: The rose petals are crushed and evenly piled; (2) Water treatment: preparing water that meets the standards for beverage use; (3) Graded extraction: The petals are mixed with the treated water and subjected to low-temperature extraction to complete the graded extraction and obtain the extract; (4) Separation and purification: The extract is subjected to initial filtration, cooling and centrifugation in sequence to effectively separate the extract and waste residue; (5) Membrane treatment: The extract is subjected to low-temperature membrane clarification and low-temperature membrane concentration in sequence to obtain a concentrated solution; (6) Sterilization: The concentrate is subjected to UHT ultra-high temperature instantaneous sterilization; (7) Freeze-drying: The sterilized concentrate is pre-frozen, dried and desorbed sequentially to obtain the rose extract; (8) Mixed packaging.

[0005] The method for preparing rose extract according to the present invention includes: in step (3), the petals and treated water are mixed at a mass ratio of 1:6, and extracted in a multifunctional extraction tank at a low temperature of 20-35℃ for 2 hours to complete the graded extraction and obtain the extract.

[0006] In step (4): The initial filtration includes: passing the extract through a 100-mesh filter to remove impurities; The cooling process includes: cooling the extract after removing impurities to 15-20°C using a pipeline cooling device; The centrifugation includes: feeding the cooled extract into a disc centrifuge at 3000 r / min to separate the extract from the waste residue, with the waste residue being automatically discharged through a tea residue trough.

[0007] In step (5): The membrane clarification includes: sending the separated and purified extract into a low-temperature membrane clarification device with a membrane pore size of 0.1 nm, and clarifying it at 30°C; The membrane concentration includes: passing the clarified extract into a low-temperature membrane concentration device and concentrating it to a solids content of 15%-20%; The UHT ultra-high temperature instantaneous sterilization conditions described in step (6) are 135°C for 3 seconds; The method for preparing rose extract according to the present invention, wherein: In step (7): The precooling includes: freezing the sterilized concentrate at -35°C for 3 hours, freezing it at -45°C for 5 hours, and then keeping it warm for 2 hours; The sequential drying process includes gradually increasing the temperature of the frozen concentrate block according to the following time and temperature: -30℃, 3h; -10℃, 3h; 0℃, 4h; 5℃, 4h; 10℃, 5h; 20℃, 6h.

[0008] The analytical drying process includes: gradually increasing the temperature of the dried material according to the following time and temperature: 25℃, 3h; 30℃, 3h; 35℃, 4h; 40℃, 8h; 45℃, 4h. The packaging method in step (8) is to use aluminum foil bags for sealed packaging, thus obtaining the product.

[0009] A method for preparing rose and white tea extracts, characterized by comprising the following steps: (1) Pretreatment: The rose petals are crushed and evenly piled; (2) Water treatment: preparing water that meets the standards for beverage use; (3) Graded extraction: The pretreated rose petals and the treated water were mixed at a mass ratio of 1:6. After soaking in the multi-functional extraction tank at a low temperature of 20°C for 2 hours, 30% of the mass of the rose petals of Tianmu Lake white tea powder was added. The extraction temperature was adjusted to ≤35°C and the extraction was continued for 1.5 hours to complete the graded extraction and obtain the compound extract. (4) Separation and purification: The extract is subjected to initial filtration, cooling and centrifugation in sequence to effectively separate the extract and waste residue; The initial filtration includes: passing the extract through a 100-mesh filter to remove impurities; The cooling process includes: cooling the extract after removing impurities to 15-20°C using a pipeline cooling device; The centrifugation includes: feeding the cooled extract into a disc centrifuge at 3000 r / min to separate the extract from the waste residue, and the waste residue is automatically discharged through a tea residue trough; (5) Membrane treatment: The purified extract was subjected to low-temperature membrane clarification and low-temperature membrane concentration at ≤30℃ to obtain a concentrated solution; the membrane clarification was carried out using a low-temperature membrane clarification device with a membrane pore size of 0.1 nm; the membrane concentration was carried out using a low-temperature membrane concentration device to concentrate the solution to a solid content of 15%-20%; (6) Sterilization: The concentrate is subjected to UHT ultra-high temperature instantaneous sterilization at 135°C for 3 seconds; (7) Freeze-drying: The sterilized concentrate is pre-frozen, dried and desorbed sequentially to obtain the rose extract; The precooling includes: freezing the sterilized concentrate at -35°C for 3 hours, freezing it at -45°C for 5 hours, and then keeping it warm for 2 hours; The sequential drying process includes gradually increasing the temperature of the frozen concentrate block according to the following time and temperature: -30℃, 3h; -10℃, 3h; 0℃, 4h; 5℃, 4h; 10℃, 5h; 20℃, 6h.

[0010] The analytical drying process includes: gradually increasing the temperature of the dried material according to the following time and temperature: 25℃, 3h; 30℃, 3h; 35℃, 4h; 40℃, 8h; 45℃, 4h. (8) Mixed packaging: The product is obtained by sealing it in aluminum foil bags.

[0011] The product obtained by the method for preparing rose extract described in this invention, or by the method for preparing rose and white tea extracts.

[0012] The product of this invention comprises: the prepared extract is in powder form, with a water content of ≤3% and a shelf life of 2 years; no solubilizing agents or desiccants are required during the preparation process, it has good solubility, dissolves instantly in water at 5°C, and has a pure flavor.

[0013] The application of the product described in this invention in food.

[0014] In the application described in this invention, the food is an instant tea beverage, which is brewed with warm water at a ratio of 1:10, or dissolved in coffee, milk, or juice for enjoyment.

[0015] The application of the rose extract prepared by the method described in this invention as a natural food preservative or antibacterial agent.

[0016] The application described in this invention, wherein: Each 1000 mL of the natural preservative contains the following substances: 5 g of rose extract, 50 mL of edible ethanol, 20 g of glycerin, and 925 mL of deionized water; The preparation method of the natural preservative includes the following steps: fully dissolving rose extract in 50 mL of edible ethanol; adding glycerin and deionized water and stirring until completely homogeneous to prepare a 0.5% rose extract preservative solution; During application, fruits, vegetables, pastries, or meat products are treated by soaking or spraying: When treating fruits and vegetables, the soaking method is used, in which the rose extract preservative solution is soaked for 1 minute, drained, and stored at room temperature; when treating pastries or meat products, the spraying method is used, in which the rose extract preservative solution is sprayed evenly on the pastries or meat products and then sealed in packaging.

[0017] The application described in this invention, wherein: Each 500 mL of the antibacterial agent comprises 3 g of rose extract and 500 mL of deionized water; the preparation method of the antibacterial agent includes the following steps: adding rose extract to deionized water and stirring until completely dissolved; filtering with a 0.22 μm filter membrane to remove bacteria, obtaining an antibacterial solution; and filling the antibacterial solution into a spray bottle to prepare a natural plant antibacterial spray; the antibacterial agent is used for antibacterial treatment of food contact surfaces, skin and mucous membranes, fruit and vegetable surfaces, or packaging materials. The preparation method and application of rose extract in this invention differ from existing technologies in that: This invention provides a method for preparing rose extract that aims to address the problems of loss of aromatic substances and active ingredients, as well as flavor deterioration, caused by traditional high-temperature processing. The method uses rose petals as raw material, which are crushed and homogenized before pretreatment, followed by low-temperature fractional extraction to obtain an extract. The extract is then subjected to initial filtration, cooling, and centrifugation, followed by membrane clarification and concentration at low temperature. The resulting concentrate is then sterilized using UHT and freeze-dried to produce the rose extract. This invention combines rose petals with a low-temperature process, eliminating the need for added solubilizing agents and desiccants. It efficiently preserves and selectively enriches the core aromatic substances in rose petals while maintaining the stability of active ingredients. The extract powder exhibits good solubility (dissolves instantly in water at 5°C) and a pure flavor, making it suitable for high-quality instant rose solid beverages and other health food products.

[0018] The rose extract obtained by the method of this invention can also be used as a natural preservative and antibacterial agent. Experimental verification has shown that it has excellent preservation and antibacterial effects.

[0019] The method of this invention is applicable to all rose varieties and has a very wide range of applications.

[0020] The preparation method and application of the rose extract of the present invention will be further described below with reference to the accompanying drawings. Attached Figure Description

[0021] Figure 1 The image shows the actual rose variety 'Hanxiang' in this invention, clearly displaying its plant shape (upright), flowers (reddish-purple, double petals), branches (curved thorns and green), and other morphological characteristics, intuitively reflecting the appearance characteristics of the variety; Figure 2 This is a flowchart of the preparation method of rose extract according to the present invention; it shows the complete process of extract production, which is divided into pretreatment; water treatment; fractional extraction; separation and purification; membrane treatment; sterilization; freeze drying; and mixing and packaging steps, and clarifies the connection between each process step; Figure 3 is a pie chart of the composition of metabolite categories in this invention; for all detected metabolites, a pie chart is drawn according to the category composition, each color represents a metabolite category, and the area of ​​the colored block indicates the proportion of that category. Figure 4 This is a volcano plot of differential metabolites in this invention: green dots (402) represent differentially regulated metabolites (such as terpenes and esters) in the RT group relative to the R group, red dots (217) represent upregulated metabolites (such as heterocyclic compounds and ethers), and gray dots represent metabolites with no significant difference. This visually presents the intensity of the difference in metabolite content between the two groups, providing data support for flavor differences. Figure 5 The radar chart of sensory flavor characteristics in this invention shows the top 10 sensory flavor characteristics in two groups. Group R has the most differential metabolites corresponding to "floral", "sweet", and "balsamic" flavors. Group RT is dominant in "herbal", "fresh", and "green" flavors, reflecting the complementary flavor effect of the compound extract. Figure 6 This invention uses a differential metabolite flavor wheel: the inner circle represents the group (R / RT), the middle circle represents the top 10 sensory flavors (the number of corresponding differential metabolites is in parentheses), and the outer circle represents the key differential metabolites. The R group is enriched with floral metabolites such as phenylacetic acid benzyl ester and geraniol; the RT group concentrates herbal and refreshing metabolites such as diphenyl ether and 3-hexen-1-ol, clarifying the material basis of flavor differences. Figure 7 This is a scatter plot of differentially expressed metabolites in this invention: different colors represent metabolite categories, the horizontal axis is log2FC (fold difference), and the size of the dots represents the VIP value. Terpenes and esters are significantly upregulated in group R (positive horizontal axis), while ethers and heterocyclic compounds are significantly upregulated in group RT (negative horizontal axis), quantifying the degree of difference among different categories of metabolites. Detailed Implementation

[0022] This invention uses the new rose variety 'Hanxiang' as an example: This variety has a plant height of 95-120cm, an upright growth habit, weak coloration of glycosides in young branches, and green curved thorns; the flowers are reddish-purple, double-petaled (50 petals), 5.7cm in diameter, strongly fragrant, and do not produce fruit; it is rich in aromatic substances: using ethyl caprylate as an internal standard, the relative content of total volatile substances in the flowers is 3704.29μg / g, including 200 substances such as sesquiterpenes, sesquiterpene alcohols, monoterpene alcohols, monoterpene derivatives, phenolic derivatives, and fatty acid derivatives, with citronellol content of 12.38μg / g and phenylethanol content of 14.35μg / g; it has strong cold resistance and resistance to dieback: two-year-old plants can grow normally outdoors in extremely cold regions with winter temperatures as low as -40 degrees Celsius; the yield is considerable: 750-800 jin of fresh flowers per mu. This variety has a strong fragrance, is cold-resistant, has good growth vigor, and produces a large number of fresh flowers, making it suitable for use in tea powder, fragrances, and landscaping.

[0023] Planting and Raw Material Acquisition of Rose 'Hanxiang': Seedlings are dug up in early April and planted before sprouting (around May 1st). After deep tilling, the soil is kept moist during routine management. Harvest when the flowers are in full bloom, selecting disease-free, intact petals as raw materials for extracts. The yield of fresh flowers per mu (approximately 0.16 acres) is controlled at 750-800 jin (approximately 375-400 catties). See attached image of Rose 'Hanxiang'. Figure 1 .

[0024] The instruments and equipment used in this invention are as follows: Pre-treatment: Air curtain dust removal tea drying and shaping equipment (ZL 202310829613.5). The equipment can absorb and purify dust to prevent external dust from entering the equipment. At the same time, it controls the rising speed of the heating gas in the heating tube to ensure that the temperature in the shaping plate groove is moderate and improve the product processing effect.

[0025] Crusher: Tea polyphenol automated conveying and extraction system (ZL 202310411132.2) realizes the simultaneous operation of raw material cleaning, crushing and dehydration, which not only helps to reduce impurities in raw materials, but also improves extraction rate and production efficiency.

[0026] Homogenizing equipment (Karl Machinery), multi-functional extraction tank (Karl Machinery), pipeline cooling device (Karl Machinery), disc centrifuge (Karl Machinery), low temperature membrane clarification equipment (Karl Machinery SPDJ-3000), low temperature membrane concentration equipment (Karl Machinery SPJS5000), UHT ultra-high temperature instantaneous sterilization device (Karl Machinery). Freeze-drying apparatus: A freeze-drying apparatus (ZL 202410969228.5) for rapid drying of tea leaves. The apparatus accelerates the heat exchange rate and reduces freezing time without damaging the petals or tea leaves, thus ensuring the good appearance and flavor of the extract.

[0027] Storage device: Tea polyphenol room temperature storage device (ZL 202310909445.0) adopts a double shell. The outer shell and the inner shell are vacuum isolated. The non-vacuum isolated area is protected by the non-convex bonding of the clamp seat and the wedge ring to prevent moisture from entering. Multiple methods are used to protect the rose fragrance extract, thereby achieving long-term storage.

[0028] Example 1

[0029] like Figure 2 As shown, a method for preparing a rose extract, using the petals of the new rose variety 'Hanxiang' as an example, includes the following steps: (1) Pretreatment: The petals of the rose 'Hanxiang' were put into a crusher for crushing, uniform piling and other treatments to improve the stability of the extract in subsequent processing; (2) Water treatment: RO reverse osmosis equipment is used to prepare treated water that meets the national food safety standard GB 19298-2014 "Packaged Drinking Water". (3) Graded extraction: The petals and treated water are mixed at a mass ratio of 1:6 and extracted in a multi-functional extraction tank at a low temperature of 20-35℃ for 2 hours to complete the graded extraction and obtain the extract. (4) Separation and purification: The extract is subjected to initial filtration, cooling and centrifugation in sequence to effectively separate the extract and waste residue; Primary filtration: The extract is first filtered through a 100-mesh filter to remove impurities; Cooling: The extract after removing impurities is cooled to 15-20℃ using a pipeline cooling device; Centrifugation: The cooled extract is fed into a disc centrifuge at 3000 r / min to separate the extract from the waste residue. The waste residue is automatically discharged through the tea residue trough.

[0030] (5) Membrane treatment: The purified extract is subjected to low-temperature membrane clarification and low-temperature membrane concentration at ≤30℃ (preferably 30℃) to obtain a concentrated solution; the membrane clarification is carried out using a low-temperature membrane clarification device with a membrane pore size of 0.1nm; the membrane concentration is carried out using a low-temperature membrane concentration device to concentrate the solution to a solid content of 15%-20%; (6) Sterilization: The concentrate is subjected to UHT ultra-high temperature instantaneous sterilization at 135°C for 3 seconds; this effectively controls microorganisms and preserves the quality of the roses. (7) Freeze-drying: The sterilized concentrate is pre-frozen, then dried sequentially and desorbed. The minimum temperature is -45℃ and the maximum is 45℃. This effectively prevents the oxidation of aromatic substances such as alcohols and phenols, and preserves their active ingredients, resulting in rose 'Hanxiang' extract powder; wherein: Pre-freezing: Freeze the sterilized concentrate at -35℃ for 3 hours, then freeze at -45℃ for 5 hours, and then keep warm for 2 hours; ; (8) Mixed packaging: Since the water content of the obtained extract is ≤3%, no desiccant is needed. It is sealed in aluminum foil bags to improve product stability and shelf life. The product has a shelf life of 2 years.

[0031] This invention involves two freezing processes, sequential drying, and analytical drying. The entire freeze-drying process utilizes a freeze-drying device designed for rapid drying of tea leaves. This device accelerates the heat exchange rate and reduces freezing time without damaging the petals or tea leaves, thus ensuring the good appearance and flavor of the extract.

[0032] The purpose of freezing in two stages is twofold: First, freezing at -35℃ achieves initial solidification of the concentrate, avoiding drastic volume shrinkage caused by direct low temperature; second, deep freezing at -45℃ allows the material to fully crystallize, forming a stable ice crystal structure, laying the foundation for subsequent sublimation drying. Gradual cooling prevents excessively large ice crystals from damaging the material's cellular structure, ensuring the retention rate of aromatic substances and active ingredients. Freezing to -45℃ in one step easily forms large ice crystals, damaging the material structure and leading to decreased solubility and loss of aromatic substances after drying.

[0033] The purpose of gradually increasing the temperature in six stages during the drying process is to achieve slow and uniform sublimation and dehydration of ice crystals by setting different holding times in different temperature ranges, based on the law of ice crystal sublimation. If the temperature is raised uniformly from -30℃ to 20℃ within 25 hours, the material will collapse and internal pores will be blocked due to excessively rapid heating, which will hinder the escape of moisture and cause problems such as clumping, dampness, and decreased solubility. The staged heating of this invention can ensure the integrity of the material structure and uniform drying, effectively avoiding collapse and component loss.

[0034] The purpose of analytical drying is to remove bound water from the material, reduce the product moisture content to ≤3%, and improve the product's stability and shelf life. Staged heating can avoid the oxidation and degradation of aromatic substances and active ingredients caused by high temperature shock, ensuring the integrity of the extract's flavor and efficacy.

[0035] Sequential drying and analytical drying are not different devices, but rather continuous process stages within the same freeze-drying unit based on the dehydration mechanism: sequential drying mainly removes free water, while analytical drying mainly removes bound water. The combination of the two makes the drying more thorough and the quality more stable.

[0036] In low-temperature vacuum mixing packaging, the extract is sealed in a vacuum environment of ≤25℃ and relative humidity ≤40% using food-grade aluminum foil vacuum bags. The low-temperature vacuum environment can prevent the extract from absorbing moisture and oxidizing during the packaging process, and the food-grade aluminum foil vacuum bags can effectively block oxygen, light and moisture, further extending the shelf life of the product without the need to add desiccants.

[0037] The preparation process in this invention is carried out at low temperatures throughout, integrating the technologies of "low-temperature fractional extraction + low-temperature membrane separation + freeze drying". This can efficiently retain and selectively enrich the core aromatic substances in the petals of the 'Hanxiang' rose, including key categories such as terpenes, esters, and alcohols (see Table 1 below for a specific comparison), thus preserving the natural flavor of the rose to the maximum extent.

[0038]

[0039] In summary, this invention integrates "low-temperature fractional extraction + low-temperature membrane separation + freeze-drying" technologies. The extraction process efficiently preserves and selectively enriches the core aromatic substances in the 'Hanxiang' rose petals without damaging the structure of the active ingredients. This solves the problems of loss of aromatic active ingredients and flavor deterioration caused by traditional high-temperature processing. The resulting rose extract has a water content of ≤3%, requires no addition of solubilizing agents or desiccants, exhibits good solubility (dissolves instantly in water at 5℃), and retains a pure flavor, providing a high-quality foundation for subsequent compound product development. It is particularly suitable for the field of high-quality instant rose tea powder and other health foods.

[0040] Example 2

[0041] A method for preparing extracts of fragrant rose and white tea includes the following steps: (1) Pretreatment: The petals of the rose 'Hanxiang' were put into a crusher for crushing, uniform piling and other treatments to improve the stability of the extract in subsequent processing; (2) Water treatment: RO reverse osmosis equipment is used to prepare treated water that meets the national food safety standard GB 19298-2014 "Packaged Drinking Water". (3) Graded extraction: The pretreated rose petals and the treated water were mixed at a mass ratio of 1:6. After soaking in the multi-functional extraction tank at a low temperature of 20°C for 2 hours, 30% of the mass of the rose petals of Tianmu Lake white tea powder was added. The extraction temperature was adjusted to ≤35°C and the extraction was continued for 1.5 hours to complete the graded extraction and obtain the compound extract. (4) Separation and purification: The extract is subjected to initial filtration, cooling and centrifugation in sequence to effectively separate the extract and waste residue; Primary filtration: The extract is first filtered through a 100-mesh filter to remove impurities; Cooling: The extract after removing impurities is cooled to 15-20℃ using a pipeline cooling device; Centrifugation: The cooled extract is fed into a disc centrifuge at 3000 r / min to separate the extract from the waste residue. The waste residue is automatically discharged through the tea residue trough.

[0042] (5) Membrane treatment: The purified extract is subjected to low-temperature membrane clarification and low-temperature membrane concentration at ≤30℃ (preferably 30℃) to obtain a concentrated solution; the membrane clarification is carried out using a low-temperature membrane clarification device with a membrane pore size of 0.1nm; the membrane concentration is carried out using a low-temperature membrane concentration device to concentrate the solution to a solid content of 15%-20%; (6) Sterilization: The concentrate is subjected to UHT ultra-high temperature instantaneous sterilization at 135°C for 3 seconds; this effectively controls microorganisms and preserves the quality of the roses. (7) Freeze-drying: The sterilized concentrate is pre-frozen, then dried sequentially and desorbed. The minimum temperature is -45℃ and the maximum is 45℃. This effectively prevents the oxidation of aromatic substances such as alcohols and phenols, and preserves their active ingredients, resulting in rose 'Hanxiang' extract powder; wherein: Pre-cooling: Freeze the sterilized concentrate at -35℃ for 3 hours, then freeze at -45℃ for 5 hours, and then keep warm for 2 hours;

[0043] (8) Mixed packaging: Since the water content of the obtained extract is ≤3%, no desiccant is needed. It is sealed in aluminum foil bags to improve product stability and shelf life. The product has a shelf life of 2 years.

[0044] like Figures 3-7 As shown, the flavor comparison descriptions of group R (fragrant rose extract) and group RT (fragrant rose + white tea compound extract) are analyzed: (1) Basic characteristics of differential metabolites: Compared with the R group, a total of 619 significantly differential metabolites were identified in the RT group, of which 402 metabolites were downregulated and 217 metabolites were upregulated. The differential metabolites were mainly concentrated in four categories: terpenes, esters, aldehydes and heterocyclic compounds. Figure 4 and Figure 7 ).

[0045] (2) Differences in core flavor compounds: In group R, the content of floral and sweet aroma metabolites such as terpenes (e.g., geraniol and linalool) and esters (e.g., ethyl phenylacetate and methyl phenyl acetate) is significantly higher. Among them, some compounds rOAV≥1 (e.g., 2,7-dimethylnaphthalene) directly contribute to the unique rich floral aroma and sweet flavor of rose. In the RT group, the addition of white tea significantly increased the levels of herbal compounds (diphenyl ethers), refreshing compounds (3-hexen-1-ol), and green compounds (2-hexenal), while also increasing the content of heterocyclic compounds (such as pyrazines), which neutralized the sweetness of the R group, creating a complex flavor profile of "floral + herbal". Figure 5 and Figure 6 ).

[0046] (3) Overall differences in sensory flavor: The R group flavor is dominated by "rich floral and sweet aroma", with balsamic and fruity aromas as secondary notes. The flavor is mellow and concentrated, which conforms to the typical flavor characteristics of traditional rose extracts and is suitable for instant tea powders that prefer pure rose flavor. The RT group's flavor profile is characterized by a complex blend of "fresh herbal notes and delicate floral aromas." The sweetness is reduced while the freshness is enhanced, resulting in a more refreshing and transparent flavor that combines the fragrance of roses with the crispness of white tea, making it suitable for a wider range of flavor applications.

[0047] Example 3

[0048] The extracts from Examples 1 and 2 can be used directly to produce instant rose solid beverage (which can be brewed with warm water at a ratio of 1:10, with a rich flavor, or dissolved in coffee, milk, juice, or other liquids for enjoyment).

[0049] Example 4

[0050] Each 1000 mL of the natural preservative contains the following substances: 5 g of fragrant rose extract, 50 mL of edible ethanol, 20 g of glycerin, and 925 mL of deionized water; The preparation method of the natural preservative includes the following steps: fully dissolving the extract of *Rosa rugosa* in 50 mL of edible ethanol; adding glycerin and deionized water and stirring until completely homogeneous to prepare a 0.5% rose extract preservative solution; During application, fruits, vegetables, pastries, or meat products are treated by soaking or spraying: When treating fruits and vegetables, the soaking method is used, in which the rose extract preservative solution is soaked for 1 minute, drained, and stored at room temperature; when treating pastries or meat products, the spraying method is used, in which the rose extract preservative solution is sprayed evenly on the pastries or meat products and then sealed in packaging.

[0051] The experimental results (preservation function) are as follows: 1) Inhibits oxidative browning: It can delay enzymatic browning in fruits and vegetables; 2) Extend shelf life: Extends the shelf life of fresh-cut fruits and vegetables such as strawberries and lettuce by 3-5 days; delays spoilage and mold growth in pastries and meat products; 3) Natural and residue-free: It replaces chemical preservatives (such as sodium benzoate) and is safe for consumption; 4) Maintain quality: preserve color and flavor, and add a rose flavor to food.

[0052] Example 5

[0053] Each 500 mL of the antibacterial agent comprises 3 g of *Rosa rugosa* extract and 500 mL of deionized water; The preparation method of the antibacterial agent includes the following steps: adding the extract of *Rosa rugosa* to deionized water and stirring until completely dissolved; filtering with a 0.22 μm filter membrane to remove bacteria to obtain an antibacterial solution; filling the antibacterial solution into a spray bottle to prepare a natural plant antibacterial spray; the antibacterial agent is used for antibacterial treatment of food contact surfaces, skin and mucous membranes, fruit and vegetable surfaces or packaging materials.

[0054] The experimental results (antibacterial function) are as follows: 1) Broad-spectrum antibacterial: It has significant inhibitory effects on Escherichia coli, Staphylococcus aureus, Salmonella, and molds; 2) Inhibits biofilm formation: It can block bacterial quorum sensing and prevent bacterial colonization; 3) Gentle antibacterial properties: Can be used for skin soothing and antibacterial care, without irritation or damage to the skin barrier; 4) Food-grade safety: Can be used for antibacterial purposes on food surfaces, leaves no chemical residues, and meets food safety requirements.

[0055] The method and application of this invention have wide applicability and are suitable for all rose varieties. The above embodiments only take the Hanxiang variety as an example. Through research, it has been found that replacing the variety with Yunnan Red Rose (Rosa rugosa 'Dian hong'), Pingyin Rose (Rosa rugosa f. plena), Kushui Rose (Rosa ×rugosa 'Kushui'), or Damask Rose (Rosa ×damascena Mill.), etc., and conducting experiments on these varieties (only the variety was replaced, and other parameters and conditions remained unchanged), similar experimental data, results, and effects were obtained, further proving the wide applicability of the method and application of this invention. It is not limited to the varieties listed above, but is also applicable to all other rose varieties.

[0056] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing rose extract, characterized in that: Using rose petals as raw material, the process includes the following steps: (1) Pretreatment: The rose petals are crushed and evenly piled; (2) Water treatment: preparing water that meets the standards for beverage use; (3) Graded extraction: The petals are mixed with the treated water and subjected to low-temperature extraction to complete the graded extraction and obtain the extract; (4) Separation and purification: The extract is subjected to initial filtration, cooling and centrifugation in sequence to effectively separate the extract and waste residue; (5) Membrane treatment: The extract is subjected to low-temperature membrane clarification and low-temperature membrane concentration in sequence to obtain a concentrated solution; (6) Sterilization: The concentrate is subjected to UHT ultra-high temperature instantaneous sterilization; (7) Freeze-drying: The sterilized concentrate is pre-frozen, dried and desorbed sequentially to obtain the rose extract; (8) Mixed packaging.

2. The method for preparing rose extract according to claim 1, characterized in that: In step (3), the petals and the treated water are mixed at a mass ratio of 1:6 and extracted in a multi-functional extraction tank at a low temperature of 20-35℃ for 2 hours to complete the graded extraction and obtain the extract. In step (4), the initial filtration includes: the extract is filtered through a 100-mesh filter to remove impurities; the cooling includes: the extract after removing impurities is cooled to 15-20°C through a pipeline cooling device; the centrifugation includes: the cooled extract is sent into a disc centrifuge and separated from the waste residue at 3000 r / min, and the waste residue is automatically discharged through a tea residue trough. In step (5), the purified extract is subjected to low-temperature membrane clarification and low-temperature membrane concentration at ≤30℃ to obtain a concentrated solution; the membrane clarification is performed using a low-temperature membrane clarification device with a membrane pore size of 0.1 nm; the membrane concentration is performed using a low-temperature membrane concentration device to concentrate the solution to a solid content of 15%-20%; The UHT ultra-high temperature instantaneous sterilization conditions described in step (6) are 135°C for 3 seconds.

3. The method for preparing rose extract according to claim 2, characterized in that: In step (7): The precooling includes: freezing the sterilized concentrate at -35°C for 3 hours, freezing it at -45°C for 5 hours, and then keeping it warm for 2 hours; The sequential drying process includes: gradually increasing the temperature of the frozen concentrate block according to the following time and temperature: -30℃, 3h; -10℃, 3h; 0℃, 4h; 5℃, 4h; 10℃, 5h; 20℃, 6h; The analytical drying process includes: gradually increasing the temperature of the dried material according to the following time and temperature: 25℃, 3h; 30℃, 3h; 35℃, 4h; 40℃, 8h; 45℃, 4h. The packaging method in step (8) is to use aluminum foil bags for sealed packaging, thus obtaining the product.

4. A method for preparing rose and white tea extracts, characterized in that: Includes the following steps: (1) Pretreatment: The rose petals are crushed and evenly piled; (2) Water treatment: preparing water that meets the standards for beverage use; (3) Graded extraction: The pretreated rose petals and the treated water were mixed at a mass ratio of 1:

6. After soaking in the multi-functional extraction tank at a low temperature of 20°C for 2 hours, 30% of the mass of the rose petals of Tianmu Lake white tea powder was added. The extraction temperature was adjusted to ≤35°C and the extraction was continued for 1.5 hours to complete the graded extraction and obtain the compound extract. (4) Separation and purification: The extract is subjected to initial filtration, cooling and centrifugation in sequence to effectively separate the extract and waste residue; The initial filtration includes: passing the extract through a 100-mesh filter to remove impurities; The cooling process includes: cooling the extract after removing impurities to 15-20°C using a pipeline cooling device; The centrifugation includes: feeding the cooled extract into a disc centrifuge at 3000 r / min to separate the extract from the waste residue, and the waste residue is automatically discharged through a tea residue trough; (5) Membrane treatment: The purified extract was subjected to low-temperature membrane clarification and low-temperature membrane concentration at ≤30℃ to obtain a concentrated solution; the membrane clarification was carried out using a low-temperature membrane clarification device with a membrane pore size of 0.1 nm; the membrane concentration was carried out using a low-temperature membrane concentration device to concentrate the solution to a solid content of 15%-20%; (6) Sterilization: The concentrate is subjected to UHT ultra-high temperature instantaneous sterilization at 135°C for 3 seconds; (7) Freeze-drying: The sterilized concentrate is pre-frozen, dried and desorbed sequentially to obtain the rose extract; The precooling includes: freezing the sterilized concentrate at -35°C for 3 hours, freezing it at -45°C for 5 hours, and then keeping it warm for 2 hours; The sequential drying process includes: gradually increasing the temperature of the frozen concentrate block according to the following time and temperature: -30℃, 3h; -10℃, 3h; 0℃, 4h; 5℃, 4h; 10℃, 5h; 20℃, 6h; The analytical drying process includes: gradually increasing the temperature of the dried material according to the following time and temperature: 25℃, 3h; 30℃, 3h; 35℃, 4h; 40℃, 8h; 45℃, 4h. (8) Mixed packaging: The product is obtained by sealing it in aluminum foil bags.

5. The product obtained by the method of preparing rose extract according to any one of claims 1 to 3 or by the method of preparing rose and white tea extract according to claim 4.

6. The product according to claim 5, characterized in that: The prepared extract is in powder form with a water content of ≤3% and a shelf life of 2 years. No solubilizing agents or desiccants are required during the preparation process. It has good solubility, dissolves instantly in water at 5℃, and has a pure flavor.

7. The application of the product according to claim 5 in food, wherein the food is an instant solid beverage, and the product is brewed with warm water at a ratio of 1:10, or dissolved in coffee, milk, or juice for enjoyment.

8. The application of the product prepared by the method of rose extract according to claim 5 as a natural food preservative or antibacterial agent.

9. The application according to claim 8, characterized in that: Each 1000 mL of the natural preservative contains the following substances: 5 g of rose extract, 50 mL of edible ethanol, 20 g of glycerin, and 925 mL of deionized water; The preparation method of the natural preservative includes the following steps: fully dissolving rose extract in 50 mL of edible ethanol; adding glycerin and deionized water and stirring until completely homogeneous to prepare a 0.5% rose extract preservative solution; During application, fruits, vegetables, pastries, or meat products are treated by soaking or spraying: When treating fruits and vegetables, the soaking method is used, in which the rose extract preservative solution is soaked for 1 minute, drained, and stored at room temperature; when treating pastries or meat products, the spraying method is used, in which the rose extract preservative solution is sprayed evenly on the pastries or meat products and then sealed in packaging.

10. The application according to claim 8, characterized in that: Each 500 mL of the antibacterial agent comprises 3 g of rose extract and 500 mL of deionized water; the preparation method of the antibacterial agent includes the following steps: adding rose extract to deionized water and stirring until completely dissolved; filtering with a 0.22 μm filter membrane to remove bacteria, obtaining an antibacterial solution, and filling the antibacterial solution into a spray bottle to prepare a natural plant antibacterial spray; the antibacterial agent is used for antibacterial treatment of food contact surfaces, skin and mucous membranes, fruit and vegetable surfaces, or packaging materials.

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