Plum extract as well as preparation method and application thereof

Abstract

The invention provides a preparation process of a plum extract, which comprises the following steps: A) pre-treating green plums, and carrying out enzymolysis by using enzyme to obtain a mixture after enzymolysis; b) extracting the mixture subjected to enzymolysis with water to obtain an extracting solution; c) concentrating the extracting solution, and precipitating with ethanol to obtain an alcohol precipitation solution; d) concentrating the alcohol precipitation solution for the second time, adding water, mixing, and precipitating to obtain a water precipitation solution; and concentrating the water precipitation liquid for three times to obtain the product. According to the preparation method disclosed by the invention, through combination of enzymolysis and specific extraction methods and conditions, the finally prepared plum extract has the characteristics of weak fruit sweetness and sour and sweet aroma, and slightly has faint scent, baking aroma and green fragrant note. The sweet-aftertaste tea has the effects of improving aroma quality and rich aroma, covering offensive odor, softening and smoothing smoke, slightly reducing irritation and residues and having sweet aftertaste, and meanwhile, the content of sour substances and sugar is high.

Description

Technical Field

[0001] The invention relates to the technical field of tobacco extracts, in particular to a plum extract and a preparation method and application thereof. Background Art

[0002] Plum is a plant of the genus Armeniaca plum Sieb. of the Rosaceae family. It is native to China and is a subtropical specialty fruit tree. Plums are sweet and mild in nature, large in fruit, thin in skin, shiny, thick in flesh, small in core, crisp and fine in texture, juicy, high in acidity, rich in various amino acids needed by the human body, and have a sweet and sour aroma. They are known as the "king of cold fruits" and "natural green health food". Plums are rich in organic acids such as citric acid and malic acid, which have the effects of relieving and eliminating fatigue. Plum extract has the effects of calming the nerves, relieving irritability, anti-tumor, improving gastrointestinal function and protecting the liver; at the same time, plum extract also has the effects of delaying aging, antibacterial, losing weight and promoting hair growth.

[0003] Plum extract has a wide range of applications, including pharmaceutical and health products, beverage and food additives, agricultural microbial disease control, and cigarette additives. As one of the traditional aroma raw materials used in cigarettes earlier, plum extract is mainly used for cigarette additives, mainly used to improve smoke morphology, increase sweetness, improve taste, and also used to enhance and enrich aroma. However, the existing preparation method of plum extract has low extraction efficiency, cumbersome extraction method, and lack of application research in cigarettes, which limits its application in the field of cigarettes.

[0004] Therefore, it is of great practical significance to develop an efficient and convenient method for preparing a plum extract whose obtained extract has a good effect in cigarettes. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a method for preparing a plum extract. The plum extract prepared by the present invention has good sensory properties and is high in acidic substances and sugar content.

[0006] The present invention provides a preparation process of a plum extract, comprising the following steps:

[0007] A) pre-treating greengage and performing enzymolysis with an enzyme to obtain a mixture after enzymolysis;

[0008] B) extracting the enzymatically hydrolyzed mixture with water to obtain an extract;

[0009] C) concentrating the extract and then precipitating it with ethanol to obtain an alcohol precipitate;

[0010] D) After the alcohol precipitate is concentrated twice, water is added to mix and precipitate to obtain a water precipitate; the water precipitate is concentrated three times to obtain.

[0011] Preferably, the pretreatment in step A) includes pitting and smoking; the smoking is performed by burning plum branches to smoke the green plums until they are 90% dry.

[0012] Preferably, the enzyme in step A) comprises one or more of cellulase, pectinase or xylanase; the amount of enzyme added is 2-4 wt%; the enzymolysis temperature is 30-50° C., and the enzymolysis time is 3-5 h.

[0013] Preferably, in step A), the enzymatic hydrolysis is performed by adjusting the pH value to 6.0-8.0 using a buffer; the buffer comprises Tris buffer, phosphate solution, citric acid-sodium citrate.

[0014] Preferably, the extraction is performed twice in step B); the solid-liquid ratio of the first extraction is 1:2-1:10, the extraction time is 3-7 hours, and the extraction temperature is 70-95°C; the solid-liquid ratio of the second extraction is 1:3-1:8, the extraction time is 4-8 hours, and the extraction temperature is 70-95°C.

[0015] Preferably, the concentration in step C) is concentrated to a relative density of 1.1 to 1.6; the concentration of ethanol is 60% to 95%, the time of ethanol precipitation is 12 to 36 hours; the solid-liquid ratio is 1:(3 to 5). Preferably, the secondary concentration in step D) is concentrated to a relative density of 1.2 to 1.5.

[0016] Preferably, in step D), the volume ratio of the alcohol precipitation solution and water is 1:(4-8); and the three concentrations are concentrated to a relative density of 1.3-1.4.

[0017] The present invention provides a plum extract, which is prepared by the preparation method described in any one of the above technical solutions.

[0018] The present invention provides a cigarette comprising the plum extract described in the above technical solution.

[0019] Compared with the prior art, the present invention provides a preparation process of plum extract, comprising the following steps: A) pre-treating green plum, enzymolyzing with enzymes to obtain a mixture after enzymolysis; B) extracting the mixture after enzymolysis with water to obtain an extract; C) concentrating the extract, precipitating with ethanol to obtain an alcohol precipitate; D) concentrating the alcohol precipitate twice, mixing with water, precipitating, and obtaining a water precipitate; the water precipitate is concentrated three times to obtain. The present invention combines the above enzymolysis with specific extraction methods and conditions, and the plum extract finally prepared has the olfactory characteristics of weak fruit sweetness, sweet and sour aroma, and slightly has a fragrance, baking fragrance and green fragrance. It has the effects of improving the aroma quality, enriching the aroma, covering up the miscellaneous smell, softening and delicate smoke, slightly reducing stimulation and residue, and having a sweet aftertaste, and at the same time, the content of sour substances and sugar is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 smoked ume plum;

[0021] Figure 2 TLC of plum;

[0022] Figure 3-1 HPLC profile of citric acid reference substance;

[0023] Figure 3-2 HPLC profile of the test sample of plum extract;

[0024] Figure 4 Chromatogram of GC-MS analysis of plum extract sample;

[0025] Figure 5-1 GC-MS analysis chromatogram of plum extract 1# liquid-liquid extraction sample;

[0026] Figure 5-2 GC-MS analysis chromatogram of 1# dispersive liquid phase microextraction sample of plum extract;

[0027] Figure 6-1 GC-MS analysis chromatogram of 2# dispersive liquid phase microextraction sample of plum extract;

[0028] Figure 6-2 GC-MS analysis chromatogram of 2# dispersive liquid phase microextraction sample of plum extract;

[0029] Figure 7-1 GC-MS analysis chromatogram of plum extract 3# liquid-liquid extraction sample;

[0030] Figure 7-2 GC-MS analysis chromatogram of 3# dispersive liquid phase microextraction sample of plum extract;

[0031] Figure 8-1 GC-MS analysis chromatogram of plum extract 4# liquid-liquid extraction sample;

[0032] Figure 8-2 GC-MS analysis chromatogram of 4# dispersive liquid phase microextraction sample of plum extract;

[0033] Figure 9-1 GC-MS analysis chromatogram of plum extract 5# liquid-liquid extraction sample;

[0034] Figure 9-2 GC-MS analysis chromatogram of 5# dispersive liquid phase microextraction sample of plum extract.

[0035] Figure 10-1 GC-MS analysis chromatogram of plum extract 6# liquid-liquid extraction sample;

[0036] Figure 10-2GC-MS analysis chromatogram of 6# dispersive liquid phase microextraction sample of plum extract;

[0037] Figure 11-1 GC-MS analysis chromatogram of plum extract 7# liquid-liquid extraction sample;

[0038] Figure 11-2 GC-MS analysis chromatogram of 7# dispersive liquid phase microextraction sample of plum extract;

[0039] Fig.12 GC-MS analysis chromatogram of 8# dispersive liquid phase microextraction sample of plum extract;

[0040] Fig.13 HPLC spectrum of plum extract sample 1#;

[0041] Fig.14 HPLC spectrum of plum extract sample 2#;

[0042] Fig.15 HPLC spectrum of plum extract sample 3#;

[0043] Fig.16 HPLC spectrum of plum extract sample 4#;

[0044] Fig.17 HPLC spectrum of plum extract sample 5#;

[0045] Fig.18 HPLC spectrum of plum extract sample 6#;

[0046] Fig.19 HPLC spectrum of plum extract sample 7#;

[0047] Fig. 20 The chromatograms are of 8 sugar working solutions;

[0048] Fig.21 HPLC chromatogram (DAD) of the mixed standard sample of 6 characteristic components;

[0049] Fig. 22 HPLC chromatogram of plum extract 1# (DAD 210nm);

[0050] Fig.23 B067 HPLC chromatogram (DAD 210 nm);

[0051] Fig.24 WY3109 HPLC chromatogram (DAD 210 nm);

[0052] Fig.25 HPLC chromatogram of plum extract validation sample (DAD210nm);

[0053] Fig.26 Overlay HPLC chromatogram of plum sample (DAD 210 nm);

[0054] Fig. 27 HPLC chromatograms (DAD 210 nm) of six characteristic component standards. DETAILED DESCRIPTION

[0055] The present invention provides a plum extract and a preparation method and application thereof. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they all fall within the scope of protection of the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application of this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0056] It should be understood that the expression "one or more of..." includes each of the items recited after the expression individually and in various different combinations of two or more of the recited items, unless otherwise understood from the context and usage. The expression "and / or" in combination with three or more recited items should be understood to have the same meaning, unless otherwise understood from the context.

[0057] The use of the terms "comprising", "having" or "containing", including their grammatical synonyms, should generally be understood as open and non-restrictive, for example not excluding other unrecited elements or steps, unless otherwise specifically stated or otherwise understood from the context.

[0058] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0059] The present invention provides a preparation process of a plum extract, comprising the following steps:

[0060] A) pre-treating greengage and performing enzymolysis with an enzyme to obtain a mixture after enzymolysis;

[0061] B) extracting the enzymatically hydrolyzed mixture with water to obtain an extract;

[0062] C) concentrating the extract and then precipitating it with ethanol to obtain an alcohol precipitate;

[0063] D) After the alcohol precipitate is concentrated twice, water is added to mix and precipitate to obtain a water precipitate; the water precipitate is concentrated three times to obtain.

[0064] The preparation process of the plum extract provided by the present invention is to pre-treat green plum first. Green plum has a weak sour aroma, slightly fruity and sweet aroma; rich aroma, improves the smoke aroma, soft smoke, improves agglomeration, reduces irritation, and slightly improves taste, so green plum is selected. The main production areas of plums are Guangdong, Yunnan, Zhejiang, Jiangsu, Guangxi, Sichuan, Jiangxi, Hubei, Guizhou and Hunan. The preferred production area is Zhejiang and the variety is green plum.

[0065] The pretreatment of the present invention comprises pitting and smoking; the smoking is to smoke the green plums by burning plum branches to make them 90% dry.

[0066] The preferred method is as follows: ripe plums are placed in a bamboo basket, tree branches and weeds are collected as fuel, fresh plums are placed on a breathable kang for smoking, the smoke passes through the bamboo dustpan on the kang to smoke the plums, the plums gradually change from yellow to black, and are smoked to 90% dry.

[0067] The enzymatically hydrolyzed mixture is extracted with water to obtain an extract.

[0068] According to the present invention, the enzyme includes one or more of cellulase, pectinase or xylanase; the added amount of the enzyme is 2-4wt%; specifically, it can be 2wt%, 3wt%, 4wt%; or the range value between any two of the above.

[0069] The enzymatic hydrolysis temperature is 30-50°C, specifically 30°C, 35°C, 40°C, 45°C or 50°C; or a range between any two of the above.

[0070] The enzymatic hydrolysis time is 3 to 5 hours; specifically, it can be 3 hours, 4 hours or 5 hours; or a range value between any two of the above.

[0071] The preferred method is as follows: weigh a certain amount of smoked green plums, add an appropriate amount of plums, adjust the pH value to an appropriate value with a buffer at an appropriate temperature, and let it stand for a period of time until the enzymatic hydrolysis is fully carried out, so as to achieve the purpose of increasing the yield of plum extract.

[0072] The enzymatic hydrolysis of the present invention is to use a buffer to adjust the pH value to 6.0-8.0, which can be 6, 7 or 8. The buffer includes Tris buffer, phosphate solution, citric acid-sodium citrate.

[0073] The enzymatically hydrolyzed mixture is extracted with water to obtain an extract.

[0074] According to the present invention, the number of extractions is two; the solid-liquid ratio of the first extraction is 1:2-1:10, specifically 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10; or a range value between any two of the above.

[0075] The extraction time is 3 to 7 hours, specifically 3 hours, 4 hours, 5 hours, 6 hours or 7 hours; or a range value between any two of the above.

[0076] The extraction temperature is 70-95°C, specifically 70°C, 75°C, 80°C, 85°C, 90°C or 95°C, or a range between any two of the above.

[0077] For the second extraction, the solid-liquid ratio is 1:3 to 1:8, specifically 1:3, 1:4, 1:5, 1:6, 1:7, 1:8; or a range value between any two of the above.

[0078] The extraction time is 4 to 8 hours, specifically 4 hours, 5 hours, 6 hours, 7 hours or 8 hours; or a range value between any two of the above.

[0079] The extraction temperature is 70-95° C., specifically 70° C., 75° C., 80° C., 85° C., 90° C. or 95° C., or a range between any two of the above.

[0080] After water extraction, the two extracts were combined.

[0081] After the extract is concentrated, ethanol precipitation is performed to obtain an alcohol precipitate.

[0082] The concentration of the present invention is to concentrate to a relative density of 1.1 to 1.6, preferably 1.1 to 1.5;

[0083] The concentration of the ethanol is 60% to 95%; preferably 70% to 95%; more preferably 95%;

[0084] The time of ethanol precipitation is 12 to 36 hours; the solid-liquid ratio is 1:3 to 5; specifically, it can be 1:3, 1:4 or 1:5; preferably, it is 1:3.

[0085] After the alcohol precipitate is concentrated twice, water is added to mix and precipitate to obtain a water precipitate; the second concentration is to concentrate to a relative density of 1.2 to 1.5, preferably 1.2 to 1.4; after stirring evenly, the precipitate is allowed to settle for 24 to 48 hours.

[0086] Specifically, the volume ratio of the alcohol precipitation liquid to water is 1:(4-8); specifically, it can be 1:4, 1:5, 1:6, 1:7, 1:8; or a range between any two of the above, preferably 1:5.

[0087] The water precipitate is concentrated three times to obtain the product, wherein the three concentrations are concentrated to a relative density of 1.3 to 1.4.

[0088] In some preferred embodiments of the present invention, the extraction process is as follows: water is selected as the extraction solvent, the extraction time is 5 hours, two extractions are performed, the two extracts are combined, concentrated to a relative density (20°C) of 1.2000±0.0080, and cooled to room temperature. 3 times the weight of 95% alcohol is added for alcohol precipitation, stirred evenly and then settled for 12-36 hours, filtered, and concentrated to a relative density of 1.3000±0.0080. 5 times the weight of water is added, stirred evenly and then settled for 24-48 hours, filtered, and concentrated to a relative density (20°C) of 1.3500±0.0080.

[0089] The present invention provides a plum extract, which is prepared by the preparation method described in any one of the above technical solutions.

[0090] The above preparation method of the present invention has been clearly described and will not be repeated here.

[0091] The present invention provides a cigarette comprising the plum extract described in the above technical solution.

[0092] The present invention does not limit the above-mentioned cigarettes, and those skilled in the art are familiar with them.

[0093] The invention uses green plum produced in Zhejiang as raw material, adopts enzymatic hydrolysis, extraction, sedimentation and concentration to prepare plum extract, has simple process and high yield.

[0094] The prepared plum extract has a weak fruity and sweet-sour aroma, with a slight fragrance, baking aroma and green fragrance. It has the effects of improving the aroma quality, enriching the aroma, covering up the miscellaneous smell, softening the smoke, slightly reducing the irritation and residue, and having a sweet aftertaste.

[0095] Through multiple extractions, alcohol precipitation, concentration, water precipitation and concentration, the macromolecular impurities in the crude plum extract, including pectin, fiber and polysaccharides, can be effectively removed, so that the quality of the plum extract product is significantly improved and the scope of application is wider.

[0096] It should be understood that the order of steps or the order in which certain actions are performed is not important as long as the present invention remains operable. In addition, two or more steps or actions may be performed simultaneously.

[0097] The use of any and all examples or exemplary language, such as "for example" or "including", herein is intended only to better illustrate the invention and does not limit the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating that any non-claimed element is essential to the practice of the invention.

[0098] In addition, the numerical ranges and parameters used to define the present invention are approximate values, and the relevant values ​​in the specific embodiments have been presented as accurately as possible. However, any numerical value inherently inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise expressly stated, it should be understood that all ranges, quantities, values ​​and percentages used in this disclosure are modified by "about". Here, "about" generally means that the actual value is within plus or minus 10%, 5%, 1% or 0.5% of a specific value or range.

[0099] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0100] Some cases are recorded in the embodiments and comparative examples of the present invention, wherein the embodiments show certain implementation modes of the present invention. However, this does not mean that the effects of the present invention can only be achieved in these cases.

[0101] To further illustrate the present invention, a plum extract provided by the present invention and its preparation method and application are described in detail below in conjunction with examples.

[0102] Example 1 Pretreatment process

[0103] (1) Smoked black plum

[0104] Take ripe plums, put them in a bamboo basket, collect tree branches and weeds as fuel, put the fresh plums on a breathable kang for smoking, and the smoke will pass through the bamboo dustpan on the kang to smoke the plums. The plums will slowly turn from yellow to black and will be 90% dry when smoked. Figure 1 Smoked ebony.

[0105] (2) Steaming black plums

[0106] Put the black plums into a bottle, cover it tightly, place it in a pot of boiling water and steam until steam starts to rise, then turn off the heat for 5 hours and take out to dry in the sun.

[0107] Table 1 Sensory evaluation of plums with different pre-treatment processes

[0108]

[0109] The results of the smoking test are shown in the table above: smoked green plum has the best smoking effect, with a weaker sour aroma, a slight fruity, sweet, baked and smoky aroma; rich aroma, improved smoke aroma, soft smoke, improved clumping, reduced irritation, and slightly improved taste. Therefore, the preferred pre-treatment process is smoked green plum.

[0110] 2.3 Plum varieties and origin screening

[0111] The main varieties of plums are white plums, green plums and red plums. Among them, white plums have a lower yield and less market supply, so they are not suitable for recommendation in the industry. Therefore, the main varieties of green plums and red plums are selected as research objects. According to the above optimized plum extraction process, the experiment was carried out, and the sensory evaluation was carried out under the same preparation process and extract density.

[0112] Table 2 Sensory evaluation of different varieties of plum extracts

[0113]

[0114] Green plum has a weaker sour aroma, with a slightly fruity and sweet aroma; it enriches the aroma, improves the smoke aroma, makes the smoke softer, improves clumping, reduces irritation, and slightly improves the taste, so choose green plum.

[0115] The main producing areas of plums are Guangdong, Yunnan, Zhejiang, Jiangsu, Guangxi, Sichuan, Jiangxi, Hubei, Guizhou and Hunan. According to the above optimized plum extraction process, the experiment was carried out, and the sensory evaluation was carried out under the same preparation process and the same extract density.

[0116] Table 3 Sensory evaluation of plum extracts from different origins

[0117]

[0118]

[0119] Zhejiang plums have a weaker sour aroma, slightly smoky and sweet aromas; the aroma texture is improved, the smoke is soft, the concentration is increased, the dryness is improved, and the throat irritation and residue are slightly increased. Therefore, the preferred origin is Zhejiang and the variety is green plum.

[0120] Example 2 selected the main variety (green plum) and the main producing area (Yunnan) for process optimization research.

[0121] First, the ethanol concentrations in the extraction step were designed as follows: 0% (water), 50% and 95%, and the extraction times were 3h, 5h and 7h respectively: the material ratios were 1:3, 1:5 and 1:7, and the extracts were collected and concentrated. Combined with the evaluation effect and yield, the optimal process for the extraction step was obtained: the material ratio was selected as 1:5, and the extraction time was 5h (starting from the reflux of the feed liquid). The extracts were collected, filtered and concentrated to a density of 1.2000±0.0080 (20°C).

[0122] Table 4 Sensory evaluation of different plum extraction processes

[0123]

[0124]

[0125] Second, in the alcohol precipitation step, the ethanol concentration used for alcohol extraction is designed to be 95%, and the alcohol extraction material-liquid ratio is 1:1, 1:3 and 1:5. 95% ethanol with different material-liquid ratios is added to the primary concentrated solution, stirred evenly, and settled for 12-36 hours at room temperature. Filter and concentrate to 1.3000±0.0080 (20°C).

[0126] Table 5 Sensory evaluation of different alcohol precipitation materials

[0127]

[0128] Comparative evaluation of the samples prepared by alcohol precipitation with three liquid ratios showed that the sample prepared by 3 times 95% alcohol had more aroma and better aroma quality, so 3 times 95% ethanol was selected as the alcohol precipitation liquid.

[0129] According to this method, a 95% ethanol extract having the same mass as ethanol is used as an alcohol precipitation liquid for alcohol precipitation, and the corresponding plum extract is prepared after filtration and concentration. Specifically, the extract obtained after the material is extracted with ethanol is firstly referred to, and then the material is extracted again with the extract.

[0130] The plum extracts prepared by the two alcohol precipitation methods were compared and evaluated. The sample prepared by alcohol precipitation with 95% ethanol had rich aroma, soft and delicate smoke, and slightly reduced irritation. Therefore, 95% ethanol was selected as the alcohol precipitation liquid.

[0131] Table 6 Sensory evaluation of different alcohol precipitation processes

[0132]

[0133] In summary, combined with the evaluation, the best extraction process is: water is selected as the extraction solvent, the extraction time is 5 hours, two extractions are performed, the two extracts are combined, concentrated to a relative density (20°C) of 1.2000±0.0080, and cooled to room temperature. Add 3 times the weight of 95% alcohol for alcohol precipitation, stir evenly and settle for 12-36 hours, filter, and concentrate to a relative density of

[0134] 1.3000±0.0080. Add 5 times the weight of water, stir evenly and let settle for 24-48 hours, filter and concentrate to a relative density (20°C) of 1.3500±0.0080. The expected yield is 23%±3%.

[0135] Example 3

[0136] According to the preferred preparation process of Example 2, three batches of samples were prepared in industrial batches by repeating the process three times. As can be seen from the table below, various indicators of the samples remained stable, meeting the requirements of process verification, and forming the production process specification of plum extract and plum quality and safety inspection form.

[0137] Table 7 Batch stability verification table of plum extract

[0138] batch Appearance Relative density (g / mL) Refraction Acid value First batch Dark brown liquid 1.3263 1.4627 241.9 Second batch Dark brown liquid 1.3231 1.4602 237.4 The third batch Dark brown liquid 1.3243 1.4618 239.1

[0139] 2.5 Quality Control of Plum Plant Raw Materials

[0140] 2.5.1 Study on Quality Control of Plum Plant Raw Materials

[0141] (1) Identification of properties

[0142] The Pharmacopoeia of the People's Republic of China (2020 edition) proposes relevant control standards for the quality of black plum plant raw materials. This product is spherical or oblate, with a diameter of 1.5 to 3 cm. The surface is black or brownish black, wrinkled and uneven, with a round pedicel mark at the base. The core is hard, oval, brownish yellow, with pits on the surface; the seeds are flat and light yellow. The smell is slight and the taste is very sour.

[0143] The powder of this product is reddish brown. There are many stone cells in the endocarp, which are scattered singly or in groups. They are almost colorless or light green-yellow, sub-polygonal, sub-circular or oblong, with a diameter of 10-72μm, thick wall, fine pores and grooves, and often contain reddish-brown substances. The non-glandular hairs are single-celled, slightly curved or hooked, and the cell cavity contains mostly yellow-brown substances. The stone cells of the seed coat are brown-yellow or brown-red, shell-shaped, helmet-shaped or sub-rectangular when viewed from the side, with a wider bottom, a half-moon-shaped or rounded outer wall, and fine layers. The epidermal cells of the pericarp are light yellow-brown, sub-polygonal when viewed from the surface, with slightly thick walls, and traces of non-glandular hairs or hairs falling off are common.

[0144] (2) Thin layer identification

[0145] According to the thin layer chromatography method (General Rule 0502), 1 to 2 μL of each solution was taken and spotted on the same silica gel G thin layer plate, and cyclohexane-chloroform-ethyl acetate-formic acid (20:5:8:0.1) was used as the developing solvent. After development, the plate was taken out, dried, sprayed with 10% sulfuric acid ethanol solution, and heated at 105°C until the spots were clearly colored. In the chromatogram of the test sample, spots of the same color appeared at the corresponding positions of the chromatogram of the reference medicinal material and the chromatogram of the reference sample. Among them, Figure 2 Plum thin layer chromatogram. 1 Control medicinal material solution 1 μL; 2 Extract test solution No. 20210301 1 μL; 3 Extract test solution No. 20210302 1 μL; 4 Extract test solution No. 20210303 1 μL.

[0146] (3) Content determination

[0147] The characteristic components of the samples and extracts obtained by the production process were studied using HPLC technology. The results are as follows:

[0148] Chromatographic column: Agilent, 4.6 mm × 250 mm × 5 μm, column temperature 25 °C.

[0149] Injection volume: 10 mL, flow rate: 1.0 mL / min. Detection wavelength: 254 nm.

[0150] The number of theoretical plates is not less than 5000.

[0151] Mobile phase A: 0.1% formic acid water B: acetonitrile, elution gradient:

[0152]

[0153] Figure 3-1 HPLC profile of citric acid reference substance; Figure 3-2 HPLC spectrum of plum extract test sample.

[0154] Table 8 Determination results of citric acid content in extracts

[0155]

[0156]

[0157] (4) Analysis of volatile components in extracts

[0158] Liquid-liquid extraction method: Take 0.050g of plum extract 20210301 sample, dissolve it in 10g of 95% ethanol, shake well, filter the solution with a 0.45μm microporous filter membrane, and wait for instrument analysis. The concentration of natural extract in the solution after dilution is about 5000ppm. Assuming that the proportion of natural extract raw materials in the flavor formula is 2.5%, the actual sample analysis concentration is 5000ppm. Figure 4 Chromatogram of GC-MS analysis of plum extract sample.

[0159] Table 9 GC-MS analysis results of plum extract samples

[0160]

[0161] (5) Other safety indicator tests

[0162] Table 10 Safety index test table

[0163] Moisture Total ash Water soluble extracts 11.0％ 1.2％ 29％

[0164] Example 4

[0165] 4.1 The commercially available plum extracts are serial numbers 1 to 7, namely Hunan China Tobacco cq22t44501, Jiangsu China Tobacco js11-11, Jiangxi China Tobacco 88573, Sichuan China Tobacco BA73601, Yunnan China Tobacco GIB211, Henan China Tobacco 88573160 and Guizhou China Tobacco GY Plum Extract B provides commercially available plum extracts. The plum extract prepared in Example 3 of the present invention is No. 8, as shown in the following table.

[0166] Table 11 Plum extract sample information

[0167]

[0168]

[0169] 4.2 Analysis of components of plum extract

[0170] 4.2.1 GC-MS qualitative and quantitative analysis

[0171] The project team selected the standard method of the digital perfumery platform as the GC-MS qualitative and quantitative analysis method for studying the volatile and semi-volatile characteristic components in plum extracts.

[0172] At the same time, considering the high viscosity and poor fluidity of plum extract, the components that can be directly extracted using solvents by liquid-liquid extraction are very limited. Therefore, liquid-liquid extraction and dispersed liquid phase microextraction were used simultaneously for pretreatment, and the components were analyzed using the standard method of the digital perfumery platform. The analysis results were compared and the pretreatment method was selected.

[0173] 4.2.1.1 Analysis methods and sample pretreatment methods

[0174] Analytical methods:

[0175] Instrument: Agilent 7890-5975C GC-MS

[0176] Chromatographic conditions: Column: DB-5MS (60m×0.25mmi.d.×0.25μmd.f.);

[0177] Inlet: temperature 250 °C, split ratio 15:1, injection volume 1 μL;

[0178] Column flow: helium, constant flow mode, 1 mL / min;

[0179] Temperature programming: Transmission line temperature: 280°C;

[0180] Mass spectrometry conditions: ion source (EI) temperature: 230 °C;

[0181] Ionization voltage: 70 eV;

[0182] Solvent delay: 4.8min;

[0183] Scanning range: 33~400.

[0184] Pre-treatment method:

[0185] (1) Liquid-liquid extraction method: Take 0.050g of plum extract sample, dissolve it in 10g of 95% ethanol, shake well, take the solution and filter it with a 0.45μm microporous filter membrane, and wait for instrument analysis. After dilution, the concentration of natural extract in the solution is about 5000ppm. Assuming that the proportion of natural extract fragrance raw materials in the fragrance formula is 2.5%, the actual sample analysis concentration is 5000ppm.

[0186] (2) Dispersive liquid phase microextraction (DLLME): Weigh 1.0 g (accurate to 0.01 g) of plum extract 10# sample into a 50 mL conical bottom stoppered centrifuge tube, measure 10 mL of ultrapure water with a measuring cylinder and add it to the centrifuge tube containing the sample, shake well, and use it as the DLLME working solution. Pipette 1 mL of dichloromethane extractant and 2 mL of acetonitrile dispersant into a chromatographic bottle, mix them, use a syringe to draw the above mixture and quickly inject it into the DLLME working solution, gently shake and sonicate for 3 minutes, then centrifuge at 4000 r / min for 5 minutes, and finally use a microinjector to draw the sediment phase for GC-MS analysis.

[0187] 4.2.1.2 Analysis results

[0188] The chromatograms obtained after analyzing the collected plum extract samples and verification samples and the analysis results obtained by automatic retrieval using the instrument workstation combined with manual retrieval are as follows.

[0189] (1) Analysis results of plum extract sample 1

[0190] Figure 5-1 GC-MS analysis chromatogram of plum extract 1# liquid-liquid extraction sample; Figure 5-2GC-MS analysis chromatogram of 1# dispersed liquid phase microextraction sample of plum extract, and the results of other plum extracts are described in the table. It can be seen from the figure that the sample of the present invention has advantages over the comparative document in benzene ring compounds, such as phenylethyl acetate and 4-hydroxy-3-methylacetophenone. And components such as furfural, guaiacol, vanillin, vanillyl acetone, and syringaldehyde. Benzene ring compounds such as phenylethyl acetate and 4-hydroxy-3-methylacetophenone usually have a specific aroma, which can provide a unique aroma for plum extract; guaiacol has a special aromatic smell and can be used as a spice to add a specific aroma to plum extract. Vanillin is an important spice with a sweet bean and powdery aroma. It can be used as a fixative, a coordinator, and a flavoring agent. Furfural is in green plum extract, and furfural substances have antibacterial and anti-inflammatory effects. They may inhibit or kill microorganisms by interfering with the cell membrane structure of microorganisms and affecting their normal physiological functions; syringaldehyde, in plum extract, may help protect other ingredients in the product from oxidative damage through its antioxidant properties, thereby extending the shelf life of the product.

[0191] Table 12 GC-MS analysis results of plum extract sample 1#

[0192]

[0193] Figure 6-1 GC-MS analysis chromatogram of 2# dispersive liquid phase microextraction sample of plum extract; Figure 6-2 GC-MS analysis chromatogram of 2# dispersive liquid phase microextraction sample of plum extract.

[0194] Table 13 GC-MS analysis results of plum extract sample 2#

[0195]

[0196]

[0197] Figure 7-1 GC-MS analysis chromatogram of plum extract 3# liquid-liquid extraction sample; Figure 7-2 GC-MS analysis chromatogram of 3# dispersive liquid phase microextraction sample of plum extract.

[0198] Table 14 GC-MS analysis results of plum extract sample 3#

[0199]

[0200]

[0201] Figure 8-1 GC-MS analysis chromatogram of plum extract 4# liquid-liquid extraction sample; Figure 8-2GC-MS analysis chromatogram of 4# dispersive liquid phase microextraction sample of plum extract.

[0202] Table 15 GC-MS analysis results of plum extract sample 4#

[0203]

[0204]

[0205] Figure 9-1 GC-MS analysis chromatogram of plum extract 5# liquid-liquid extraction sample; Figure 9-2 GC-MS analysis chromatogram of 5# dispersive liquid phase microextraction sample of plum extract.

[0206] Table 16 GC-MS analysis results of plum extract sample 5#

[0207]

[0208]

[0209] Figure 10-1 GC-MS analysis chromatogram of plum extract 6# liquid-liquid extraction sample; Figure 10-2 GC-MS analysis chromatogram of 6# dispersive liquid phase microextraction sample of plum extract.

[0210] Table 17 GC-MS analysis results of plum extract sample 6#

[0211]

[0212]

[0213] Figure 11-1 GC-MS analysis chromatogram of plum extract 7# liquid-liquid extraction sample; Figure 11-2 GC-MS analysis chromatogram of 7# dispersive liquid phase microextraction sample of plum extract.

[0214] Table 18 GC-MS analysis results of plum extract sample 7#

[0215]

[0216]

[0217] Fig.12 GC-MS analysis chromatogram of 8# dispersive liquid phase microextraction sample of plum extract

[0218] Table 19 GC-MS analysis results of plum extract sample 8#

[0219]

[0220]

[0221] 4.2.2 Liquid chromatography analysis of plum extract

[0222] 4.2.2.1 Preparation of sample solution to be tested.

[0223] Accurately weigh 1 g of the above 1#, 2#, 3#.4#.5#.6#.7# plum extract samples, add 10 mL of methanol, ultrasonically extract for 30 min, filter, and then pass through a 0.45 μm filter membrane to obtain a sample solution.

[0224] 4.2.2.2 Liquid chromatography analysis conditions

[0225] Chromatographic column: Agilent, 4.6 mm × 250 mm × 5 μm, column temperature 25 °C.

[0226] Injection volume: 10 mL, flow rate: 1.0 mL / min. Detection wavelength: 254 nm.

[0227] The number of theoretical plates is not less than 5000.

[0228] Mobile phase A: 0.1% formic acid water B: acetonitrile, elution gradient:

[0229]

[0230]

[0231] 4.2.2.3 Test results

[0232] Under the above conditions, the HPLC chromatograms of the standards and samples are as follows: Fig.13 HPLC spectrum of plum extract sample 1#; Fig.14 HPLC spectrum of plum extract sample 2#; Fig.15 HPLC spectrum of plum extract sample 3#; Fig.16 HPLC spectrum of plum extract sample 4#; Fig.17 HPLC spectrum of plum extract sample 5#; Fig.18 HPLC spectrum of plum extract sample 6#; Fig.19 HPLC spectrum of plum extract sample 7#.

[0233] 4.2.3 Detection of small molecule sugars in plum extract

[0234] The detection principle of small molecule sugars in plum extract is to use pure water to extract the sample, and use a liquid chromatograph equipped with a CAD detector to determine the content of small molecule sugars such as arabinose, fructose, sorbitol, glucose, inositol, sucrose, maltose, maltotriose, etc. in the diluted sample, and then calculate the content of each small molecule sugar in the original sample.

[0235] 3.2.3.1 Instruments and methods

[0236] Instruments and equipment:

[0237] UltiMate3000 liquid chromatograph (Thermo Fisher Scientific, USA); equipped with CoronaVeo RS charged aerosol detector (CAD); Prevail Carbohydrate ES chromatographic column (5 μm, 250 mm×4.6 mm) (Grace, USA); CP2245 electronic balance (sensitivity 0.0001 g, Sartorius, Germany).

[0238] Reagents and drugs:

[0239] Fructose (≥99%); glucose (≥99.5%); sucrose (≥99.5%); maltose monohydrate (≥99%); maltotriose (≥99%); inositol (≥99%); arabinitol (≥99%); sorbitol (≥99%); (Sigma-Aldrich, USA); ultrapure water (Milli-Q).

[0240] Standard stock solution:

[0241] Accurately weigh 30 mg of arabitol, 100 mg of fructose, 50 mg of sorbitol, 200 mg of glucose, 80 mg of sucrose, 60 mg of maltose, 30 mg of maltotriose, and 50 mg of inositol (accurate to 0.1 mg) into a 10 mL volumetric flask, add 4 to 6 ml of pure water, ultrasonically dissolve and dilute to the scale, mix well to obtain a mixed standard stock solution (see Figure 3-23 for the chromatogram of the sugar standard).

[0242] Standard working solution:

[0243] Accurately pipette 25 μL, 50 μL, 100 μL, 250 μL, 500 μL, 750 μL, and 1000 μL of the standard stock solution into a 10 mL volumetric flask, dilute to the mark with pure water, and mix well to obtain seven concentrations of working standard solutions.

[0244] Sample pretreatment method:

[0245] Take 100 mg of sample in a volumetric flask, add purified water, dissolve under ultrasonication for 5 min, make up to 10 mL, take 1 mL of solution and filter through 0.22 μm filter membrane and then enter liquid chromatography for quantitative analysis.

[0246] Instrument conditions:

[0247] Chromatographic column: Prevail Carbohydrate ES chromatographic column (5μm, 250mm×4.6mm);

[0248] Flow rate: 0.8 mL / min; column temperature: 30 °C; injection volume: 10 μL;

[0249] Mobile phase: acetonitrile and water;

[0250] Gradient elution: 80% acetonitrile + 20% water (0 min), 80% acetonitrile + 20% water (20 min), 75% acetonitrile + 25% water (24 min), 55% acetonitrile + 45% water (26 min), 55% acetonitrile + 45% water (33 min), 80% acetonitrile + 20% water (37 min), 80% acetonitrile + 20% water (40 min);

[0251]

[0252] CAD parameters: column temperature: 30°C; injection volume: 10 μL; CAD nebulizer temperature: 35°C; nitrogen pressure: 241 kPa; output range: 100 pA.

[0253] 3.2.3.2 Analysis results

[0254] The chromatogram of the mixed standard sample of 8 sugars is as follows Fig. 20 The working curves, linear ranges and correlation coefficients of each component are shown in Table 20. Fig. 20 The chromatograms are of 8 sugar working solutions.

[0255] Table 20 Working curves, linear ranges and correlation coefficients of 8 sugar components

[0256] Target Working curve <![CDATA[Linear range / (μg·mL -1 )]]> <![CDATA[R 2 ]]> Arabitol y=0.1117x+0.8219 14.95-299 0.9999 fructose y=0.1126x+0.8040 50-1000 0.9985 Sorbitol y=0.0813x+0.8794 25-500 0.9988 glucose y=0.1263x+0.7566 100-2000 0.9994 Inositol y=0.0916x+0.8463 25-500 0.9954 sucrose y=2.0235x+0.0153 40.1-802 0.9920 maltose y=0.8122x+0.0097 30-600 0.9950 Maltotriose y=0.3671x+0.0088 15-300 0.9961

[0257] Table 21 Content (mg / g) and RSD (n=5) / % of 8 kinds of sugar components in several plum extracts

[0258]

[0259]

[0260] It can be seen from the data in the table that the sugars contained in several plum extracts are mainly fructose, sorbitol, glucose and sucrose, 6 of which contain maltose, 4 of which contain maltotriose, and none of them contain arabinose and inositol.

[0261] In plum extract, fructose can provide sweetness and enhance the flavor of plums, but fructose is one of the sweetest natural sugars. Therefore, in order to ensure that the extract does not taste too sweet, the fructose content should be moderate and not too high; in plum extract, sorbitol can be used as a sweetener, and it also has moisturizing properties, which helps to maintain the moistness and taste of the plum extract; in plum extract, sucrose can not only provide sweetness, but also increase the flavor and taste of the plums.

[0262] 4.2.4 Detection of Acid in Plum Extract

[0263] It can be seen from the results of gas chromatography-mass spectrometry that the types and contents of volatile and semi-volatile aroma components in the plum extract sample taken by the present invention are not many. According to literature reports, six organic acid components, namely D-gluconic acid, DL-malic acid, L-lactic acid, citric acid, succinic acid and isovaleric acid, are characteristic components with relatively high contents in plums. Therefore, an analysis method for these organic acids was established using liquid chromatography, and the contents of these six organic acids in several existing plum extracts were detected.

[0264] 4.2.4.1 Instruments and methods

[0265] Instruments and equipment:

[0266] UltiMate 3000 liquid chromatograph (Thermo Fisher Scientific, USA) was equipped with CoronaVeo RS charged aerosol detector (CAD) and diode array detector (DAD); C18 chromatographic column (5 μm, 250 mm × 4.6 mm) (Agilent, USA); CP2245 electronic balance (sensitivity 0.0001 g, Sartorius, Germany).

[0267] Reagents and drugs:

[0268] Formic acid: analytical grade, Sinopharm Group; methanol and acetonitrile: chromatographic grade, Thermo Fisher; D-gluconic acid, DL-malic acid, L-lactic acid, citric acid, succinic acid and isovaleric acid: purity ≥98%, Chengdu Pufeide Biotechnology Co., Ltd.; experimental water: Milli-Q ultrapure water.

[0269] 4.2.4.2 Optimization of chromatographic conditions

[0270] Choose ThermoHypersil GOLD C 18(4.6mm×250mm, 5μm) chromatographic column. The analysis of organic acids requires an acid stronger than formic acid as the mobile phase. The experiment compared phosphoric acid and trifluoroacetic acid, and the results showed that phosphoric acid was better. The project selected acetonitrile-0.1% phosphoric acid water as the mobile phase for gradient elution. Six organic acids, including D-gluconic acid, DL-malic acid, L-lactic acid, citric acid, succinic acid and isovaleric acid, all have strong ultraviolet absorption, and the DAD detector can be used. Fig.21 This is the HPLC chromatogram (DAD) of a mixed standard sample of six characteristic components.

[0271] 4.2.4.3 Optimized chromatographic conditions

[0272] Chromatographic column: ThermoHypersil GOLD C 18 Column (250 mm × 4.6 mm, 5 μm); mobile phase: 0.1% phosphoric acid water (A) - acetonitrile (B); gradient elution conditions see Table 3-12; column temperature: 25 ° C; injection volume: 10 μL; DAD detection wavelength: 210 nm.

[0273] Table 22 Gradient elution conditions

[0274]

[0275]

[0276] 4.2.4.4 HPLC analysis of six acids in plum extract

[0277] The HPLC method established in 3.2.4.3 is used, and the chromatogram is shown in Fig. 22 , 23 , 24 and Fig.25 Comparing the retention time of the standard, the results showed that six characteristic components, including D-gluconic acid, DL-malic acid, L-lactic acid, citric acid, succinic acid and isovaleric acid, could be detected in the four plum extract samples. Fig. 22 HPLC chromatogram of plum extract 1# (DAD 210nm); Fig.23 B067HPLC chromatogram (DAD 210nm);

[0278] Fig.24 WY3109 HPLC chromatogram (DAD 210 nm). Fig.25 HPLC chromatogram of plum extract validation sample (DAD210nm)

[0279] 4.2.4.5 Determination of target characteristic components

[0280] Fig.26 It is compared by superimposing the arrangement Figure 22 to Figure 25It can be clearly seen that the six characteristic components, including D-gluconic acid, DL-malic acid, L-lactic acid, citric acid, succinic acid and isovaleric acid, can be detected at 210nm on the DAD detector. However, the components of plum extract and plum fragrance raw materials are relatively complex. The sum of the relative peak areas of the six characteristics accounts for about 10.66% to 18.89% of each sample. At present, the project team still intends to select six characteristic components, including D-gluconic acid, DL-malic acid, L-lactic acid, citric acid, succinic acid and isovaleric acid, for quality evaluation, and compare the standard and characteristic spectra. The retention times are 6.12, 7.13, 8.12, 9.44, 11.15 and 25.29min, respectively. Further research is needed in the later stage. Fig.26 Overlay HPLC chromatogram of plum sample (DAD 210nm)

[0281] 4.2.4.6 Drawing of standard curve

[0282] Accurately weigh 10 mg (accurate to 0.1 mg) of each of D-gluconic acid, DL-malic acid, L-lactic acid, citric acid, succinic acid and isovaleric acid, dissolve them in methanol and make up to 10 mL to obtain a single standard stock solution. Store at 0-4°C and obtain the retention time of each substance under the chromatographic conditions of 3.2.4.3. The results are shown in Table 1. Fig. 27 The mixed standard working solution was prepared from these stock solutions in methanol at different concentrations. Fig. 27 HPLC chromatograms (DAD 210 nm) of six characteristic component standards.

[0283] 4.2.4.7 Establishment of standard curve

[0284] Mixed standard working solutions with different mass concentrations were injected 5 times continuously under the chromatographic conditions of 3.2.4.3 and analyzed by HPLC-DAD. Linear regression was performed with the concentration of the standard working solution as the horizontal axis and the chromatographic peak area as the vertical axis, and finally the regression equations of the 6 characteristic components were obtained. The detection limit and quantification limit of the sample were calculated by 3 times and 10 times the signal-to-noise ratio respectively. The results showed that the 6 characteristic components showed a good linear relationship under the DAD detection conditions.

[0285] Table 230 Linear range, regression equation and correlation coefficient of 6 characteristic components

[0286]

[0287] 4.2.4.8 Methodological evaluation

[0288] The methodological evaluation was carried out in the same manner as in 4.2.4.3. The results showed that the precision, stability, repeatability and recovery rate of this method were all good.

[0289] 4.2.4.9 Results of acid test in plum extract

[0290] Table 24 Content (mg / g) and RSD (n=3) / % of six acids in several plum extracts

[0291]

[0292] It can be seen from the test results that all 8 plum extracts contain DL-malic acid and citric acid, and the content of both acids exceeds 70 mg / g. The book "Tobacco Fragrance Raw Materials" points out that malic acid is used in tobacco for seasoning and improving aroma. The conversion of DL-malic acid helps to reduce the sour taste in plum extracts, increase fruity and floral aromas, and enhance the flavor. Citric acid is a seasoning for tobacco, which alleviates the spicy and miscellaneous taste of smoke, inhibits irritation, and is also used as a mildew preventive. At present, these 6 organic acids, combined with the content of malic acid and citric acid and their role in tobacco, are used as characteristic components in plum extracts. Although the content of citric acid and malic acid in 5# is moderate, the sucrose content in sugar is relatively high, which will break the balance and affect the taste.

[0293] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A process for preparing a plum extract, characterized in that: The steps include: A) pre-treating greengage and performing enzymolysis with an enzyme to obtain a mixture after enzymolysis; B) extracting the enzymatically hydrolyzed mixture with water to obtain an extract; C) concentrating the extract and then precipitating it with ethanol to obtain an alcohol precipitate; D) after the alcohol precipitate is concentrated twice, water is added to mix and precipitate to obtain a water precipitate; The water precipitate is concentrated three times to obtain the product.

2. The preparation process according to claim 1, characterized in that: Step A) The pretreatment includes pitting and smoking; the smoking is performed by burning plum branches to smoke the green plums until they are 90% dry.

3. The preparation process according to claim 1, characterized in that: Step A) The enzyme comprises one or more of cellulase, pectinase or xylanase; the added amount of the enzyme is 2-4 wt%; the enzymolysis temperature is 30-50° C., and the enzymolysis time is 3-5 hours.

4. The preparation process according to claim 1, characterized in that: Step A) The enzymatic hydrolysis is performed by adjusting the pH value to 6.0-8.0 using a buffer; the buffer comprises Tris buffer, phosphate solution, and citric acid-sodium citrate.

5. The preparation process according to claim 1, characterized in that: Step B) The extraction is performed twice; the first extraction has a solid-liquid ratio of 1:2 to 1:10, an extraction time of 3 to 7 hours, and an extraction temperature of 70 to 95°C; the second extraction has a solid-liquid ratio of 1:3 to 1:8, an extraction time of 4 to 8 hours, and an extraction temperature of 70 to 95°C.

6. The preparation process according to claim 1, characterized in that: Step C) The concentration is concentrated to a relative density of 1.1 to 1.6; the concentration of ethanol is 60% to 95%, the time of ethanol precipitation is 12 to 36 hours; the solid-liquid ratio is 1:(3 to 5).

7. The preparation process according to claim 1, characterized in that: The secondary concentration in step D) is to concentrate to a relative density of 1.2 to 1.

5.

8. The preparation process according to claim 1, characterized in that: Step D) the volume ratio of the alcohol precipitation liquid and water is 1: (4-8); the three concentrations are concentrated to a relative density of 1.3-1.

4.

9. A plum extract, characterized in that The compound is prepared by the preparation method according to any one of claims 1 to 8.

10. A cigarette, characterized in that: The invention comprises the plum extract according to claim 9.

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