Preparation method of peony flower concentrated stock solution rich in aroma components and application of peony flower concentrated stock solution in essence / spice

Abstract

The invention belongs to the technical field of peony flower processing, and particularly relates to a preparation method of a peony flower concentrated stock solution rich in aroma components and application of the peony flower concentrated stock solution in essence / spice. The preparation method of the peony flower concentrated stock solution comprises the following steps: sequentially carrying out pre-cooling and deep cooling on peony flowers, then shearing and crushing in a circulating liquid nitrogen atmosphere, then carrying out enzymolysis by adopting ultrasonic-assisted biological enzyme to obtain an enzymatic hydrolysate, finally intercepting a product-enriched solution with a specific molecular weight through an ultrafiltration membrane, and concentrating the product-enriched solution. The fresh peony flowers are subjected to precooling and cryogenic treatment, so that the loss of active substances such as polyphenol can be avoided, and the browning of the materials is avoided; besides, aroma components in the fresh petals can be reserved to the maximum extent, the problem that volatile aroma components are lost due to smashing operation at the high temperature or the normal temperature is solved, and finally, the prepared peony flower stock solution contains rich volatile aroma components such as linalool oxide, citronellol and benzoic acid; wide application prospects are realized in skin care products and essence / spices.

Description

Technical Field

[0001] The invention belongs to the technical field of peony flower processing, and particularly relates to a preparation method of peony flower concentrated stock solution rich in aroma components and application of the same in essence / spices. Background Art

[0002] Peony flowers are rich in various active ingredients including polyphenols, flavonoids, and aroma components such as citronellol, geraniol, and benzoic acid. So far, the main effects of the active ingredients of peony flowers that have been reported include: whitening effects such as inhibiting tyrosinase activity, antioxidant effects such as scavenging free radicals, anti-wrinkle effects such as inhibiting elastase activity, anti-glycation effects, anti-inflammatory effects, etc. Therefore, peony flowers are often used as cosmetic raw materials.

[0003] However, in the processing of peony flowers, it is generally necessary to pulp or crush them before proceeding to the next step. However, since the petals of peony flowers are soft, they are very easy to form a mass or paste during the crushing process, and the active ingredients therein are not easy to be completely dissolved. In addition, browning is easy to occur during the pulping process, resulting in a darker color of the extract and an additional decolorization step. At the same time, the traditional processing method is very likely to cause the aroma components in the peony flowers, such as oxidized linalool and benzoic acid, to volatilize or even be destroyed and lost.

[0004] This problem can be solved by cryogenic grinding. Since the material reaches a brittle state during the low-temperature (≤-20°C) grinding and wall-breaking process, peony whole powder with a smaller grinding particle size (below 200~300 mesh) can be obtained, avoiding the loss of active substances. At the same time, it can prevent the material from browning and deepening in color, which is beneficial to improving the solubility and bioavailability of small molecule functional substances in cells and retaining the aroma components in peony flowers as much as possible.

[0005] Although low-temperature freezing can make peony flowers brittle and easier to grind into powder, their solid content is still less than ideal, which means that the active ingredients are still retained to a large extent.

[0006] In order to obtain the active ingredients in peony flowers to the greatest extent and avoid their loss during processing, the existing processing technology needs to be improved. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a method for preparing a peony flower concentrated stock solution rich in aroma components and application of the same in flavors / spices.

[0008] The method for preparing the peony flower concentrated stock solution rich in aroma components provided by the present invention comprises the following steps: (1) Take fresh peony flowers, precool them at -20~-18℃ for 4~6 hours, and then deep freeze them at -55~-45℃ for 4~6 hours. Take the frozen peony flowers and shear and crush them in a circulating liquid nitrogen atmosphere. The liquid nitrogen temperature in the chamber and pipeline of the crushing equipment is the same as the cryogenic temperature, which is -55~-45℃. Sieve the powder to obtain peony flower full micronized powder with a particle size of less than 50 μm. (2) taking the peony flower whole powder obtained in (1), adding a complex enzyme and performing enzymolysis under ultrasonication to obtain an enzymolysis solution; Based on the weight of dry peony flower powder, the addition amount of cellulase and neutral protease in the complex enzyme is 20-30 U / g and 20-50 U / g respectively; (3) centrifuging the enzymatic hydrolysate obtained in (2), retaining the supernatant, and filtering the supernatant using an ultrafiltration membrane to obtain a product enriched solution; (4) The product enriched liquid obtained in (3) is subjected to low-temperature vacuum film concentration, sterilization, and filtration to obtain a peony flower concentrated stock solution rich in aroma components.

[0009] The present invention adopts a method of precooling combined with deep cold crushing to treat peony flowers. On the one hand, it is conducive to the dissolution of active ingredients in peony flowers; on the other hand, since peony flowers contain a large number of aroma components, most of which are highly volatile and not resistant to high temperatures, if they are treated at high temperatures, they will inevitably cause a large amount of loss due to volatilization; even if they are crushed at room temperature, a large amount of volatile aroma components will be lost. Therefore, the present invention can "lock" the aroma components through the treatment of precooling and deep cold crushing, and can retain these aroma components to the maximum extent during crushing, so that the product peony flower concentrated stock solution retains these volatile aroma components as much as possible.

[0010] In the above-mentioned method for preparing the concentrated peony flower liquid rich in aroma components, preferably, in (2), before using the composite enzyme for enzymolysis, citric acid buffer is first added at a material-liquid mass ratio of 1:4-6, and the pH value of the mixed solution is adjusted to 5.5-6.5. The complex enzyme was used for enzymatic hydrolysis at room temperature for 1-3 h. Ultrasonic treatment was performed 1-3 times during the enzymatic hydrolysis. After each ultrasonic treatment for 0.5 h, another ultrasonic treatment was performed at an interval of 0.5 h. The ultrasonic power was 20-50 kHz.

[0011] Preferably, in the refrigerated centrifugation described in (3), the centrifugal speed is 8000-10000 rpm, the centrifugal time is 10-15 min, and the temperature is 0-4°C.

[0012] Preferably, in (3), the supernatant is retained by an ultrafiltration membrane to obtain a product enriched solution with a molecular weight cut-off of less than 6000 Da.

[0013] Preferably, the low-temperature vacuum thin film concentration described in (4) has an evaporation temperature of ≤50°C, and is concentrated to 1 / 4 to 1 / 6 of the volume of the enriched liquid, and then a citric acid buffer is added to adjust the pH value to 5.5 to 6.0.

[0014] Preferably, the sterilization temperature described in (4) is 65-85°C, and the sterilization time is 15-30 min.

[0015] In addition, the present invention also provides a product containing the above-mentioned peony flower concentrated liquid rich in aroma components, wherein the product is obtained by adding a product stability enhancer to the peony flower concentrated liquid rich in aroma components and stirring evenly, wherein 2 to 5 g of the product stability enhancer is added to every 100 mL of the peony flower concentrated liquid rich in aroma components.

[0016] Preferably, the product stability enhancer is prepared by the following method: Add 20-40 mL of peony seed oil, 3-5 g of sodium lactate, and 100 mL of water into a reaction tank, stir and heat to 60-80°C, then add 0.4-0.6 g of ε-polylysine hydrochloride and 2-3 g of methyl hydroxybenzoate, stir and then add citric acid buffer, adjust the pH to 5.5-6.0, then add 10-20 g of chitosan, stir evenly, and cool to room temperature to obtain a stability enhancer.

[0017] Furthermore, the use of the peony flower concentrated liquid rich in aroma components or the above-mentioned product in skin care products is also the key protection content of the present invention.

[0018] In addition, the use of the peony flower concentrated liquid rich in aroma components or the above-mentioned product in flavors / spices also falls within the protection scope of the present invention.

[0019] The beneficial effects of the present invention are: (1) The present invention uses a combination of precooling and deep-cold crushing to treat peony flowers, which can not only significantly increase the solid content in the extract and promote the dissolution of active ingredients, but most importantly, can retain the volatile aroma components in the peony flowers to the maximum extent; For example, in the peony flower concentrated stock solution obtained by the method of the present invention, the content of linalool oxide in its aroma components can reach 7.32%, and the proportions of citronellol, geraniol, and benzoic acid are 0.84%, 0.93%, and 0.77%, respectively. In addition, the total flavonoid content can reach 25.79%. The total flavonoid content reflects the high content of active ingredients on the one hand, and on the other hand, the total flavonoids also contain a part of volatile aroma components. The high content of the flavonoids also means that the content of the volatile aroma components will also be correspondingly high. (2) In the process of enzymatic hydrolysis of peony flower powder, the effect of ultrasound is helpful to further break the matrix barrier that hinders the dissolution of active ingredients, strengthen the mass transfer of powder, and promote the dissolution of active ingredients; at the same time, the macromolecular components such as fiber and protein in the matrix can be decomposed into oligosaccharides, short peptides and amino acids under the action of ultrasound, further improving the biological activity of the enzymatic hydrolysate; (3) By comparing the enrichment effects of ultrafiltration membranes of different specifications on active ingredients, the ultrafiltration membrane that is most conducive to the enrichment of active ingredients was selected. The experimental results showed that the product part of ≤6000Da obtained by ultrafiltration membrane interception had an inhibition rate of 73.23% on tyrosinase, an inhibition rate of 50.19% on cell melanin production, and an inhibition rate of 63.45% on cell secretion of TNF-α. It has a better whitening effect than products with other molecular weights. In addition, the stock solution is rich in aroma components. Therefore, the peony flower concentrated stock solution or product provided by the present invention has a good application prospect in skin care products or cosmetics, flavors, fragrances and other products; (4) The present invention also provides a product stability protecting agent. By adding the product stability protecting agent to the prepared peony flower concentrated stock solution rich in aroma components, it helps the product maintain good long-term effectiveness and stability during long-term storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the inhibition curve of the peony flower concentrated stock solution rich in aroma components prepared in Example 4 of the present invention on tyrosinase activity; Figure 2 The inhibition of melanin synthesis in B16F10 cells at different concentrations by the concentrated peony flower solution rich in aroma components prepared in Example 4 of the present invention; Figure 3 The inhibition of TNF-α secretion by RAW264.7 cells at different concentrations of the concentrated peony flower solution rich in aroma components prepared in Example 4 of the present invention; Figure 4 This is a state diagram of peony flower concentrated liquid obtained by different methods after being placed at room temperature for one month. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in conjunction with specific implementation methods.

[0022] Example 1 This example focuses on examining the particle sizes of fresh peony flowers and the contents of active ingredients therein obtained at different freezing and crushing temperatures during the freezing treatment of fresh peony flowers.

[0023] The specific experimental operation of this embodiment is as follows: Take fresh peony flowers, precool them at -18℃ for 5 h, and then place them in the temperature range of -80~-20℃ for deep freezing for 5 h. Take the frozen peony flowers and shear and crush them in a circulating liquid nitrogen atmosphere. The temperature in the cavity and pipeline of the crushing equipment is the same as the crushing temperature, which is -80~-20℃. Sieve the powder to obtain peony flower full powder with a particle size of less than 50 μm.

[0024] In addition, when the crushing temperature is room temperature (23°C), the peony flowers are no longer pre-cooled or deep-cooled under this condition.

[0025] The particle size of the peony flower whole micro powder obtained at different deep-cold grinding temperatures and the content of the active ingredients therein are shown in Table 1 below.

[0026] Table 1 Particle size and component yield at different crushing temperatures Crushing temperature / ℃ <![CDATA[D 50 / μm]]> <![CDATA[D 90 / μm]]> Polyphenols / mg / g Flavonoids / mg / g Main aroma substances / % Room temperature / 23 386.47 674.70 28.17 5.48 7.54 -20 107.70 237.23 48.59 10.82 8.89 -40 65.74 208.67 62.12 11.82 9.43 -50 45.61 199.53 72.01 12.17 11.76 -60 72.47 237.23 65.12 10.43 11.02 -80 102.23 239.20 59.77 10.05 10.22

[0027] Note: The main aroma substances are calculated based on the contents of oxidized linalool, citronellol, geraniol and benzoic acid, the same below.

[0028] Table 1 shows that the particle size of peony flower whole powder obtained at different grinding temperatures is significantly different. At the same time, the content of polyphenols and flavonoids in the whole powder also shows great differences. When the grinding temperature is -50°C, the particle size of the peony flower whole powder obtained is the smallest, and the content of polyphenols and flavonoids in the whole powder is also the highest. When the grinding temperature continues to drop to -60°C or even -80°C, the particle size of the peony whole powder actually rises.

[0029] Therefore, in order to obtain a better pulverizing effect, the pulverizing temperature is set to -50°C in the present invention.

[0030] Furthermore, the present invention investigates the effects of precooling and cryogenic treatment on the pulverization process, that is, pulverization is performed directly at a specific temperature (i.e., -20°C, -50°C, -80°C) without precooling and cryogenic treatment. The experimental results are shown in Table 2 below.

[0031] Table 2 Particle size and component yield after cryogenic treatment without precooling Crushing temperature / ℃ <![CDATA[D 50 / μm]]> <![CDATA[D 90 / μm]]> Polyphenols / mg / g Flavonoids / mg / g Main aroma substances / % -20 343.20 706.9 25.34 5.54 5.31 -50 317.89 642.58 26.07 4.87 6.88 -80 310.73 673.28 28.93 5.88 6.31

[0032] The data in the table show that even at the same crushing temperature, the peony flower bodies that have not been pre-cooled and deep-cooled have larger particle sizes and poor crushing effects. This may be because without pre-cooling and deep-cooling in advance during crushing, the internal and external temperatures of the peony petals are difficult to reach the crushing temperature and undergo glass transition within a short crushing time, thus affecting the crushing effect.

[0033] In addition, the above results also show that precooling, deep freezing treatment and ultrafine grinding at deep freezing temperature have a significant effect on the content of aroma components in peony flower concentrated liquid. The precooling and deep freezing treatment can well "lock" the aroma components, and these aroma components can be retained to the maximum extent during low-temperature grinding, which is beneficial to retain as many volatile aroma components as possible in the final product peony flower concentrated liquid.

[0034] Example 2 This example focuses on exploring the effect of the enzymatic hydrolysis process of peony whole micropowder on the extraction of active ingredients from peony flowers. The specific experimental operation is as follows: (1) Take fresh peony flowers, precool them at -18°C for 5 h, and then deep freeze them at -50°C for 5 h. Take the frozen peony flowers and shear and crush them in a circulating liquid nitrogen atmosphere. The liquid nitrogen temperature in the chamber and pipeline of the crushing equipment is -50°C. Sieve the powder to obtain peony flower full micronized powder with a particle size of less than 50 μm. (2) The peony flower whole powder obtained in (1) was treated by the following methods: cellulase treatment only, neutral protease treatment only, cellulase and neutral protease combined enzyme treatment, and ultrasound-assisted combined enzyme treatment.

[0035] The active ingredients in the enzymatic hydrolysate obtained after different treatments are shown in Table 3 below.

[0036] Table 3 Yield of active ingredients in the enzymatic hydrolysates obtained after different enzymatic hydrolysis treatments Group Soluble solids / mg / g Polyphenols / mg / g Flavonoids / mg / g Cellulase 20 U / g 409.36 122.83 19.68 Neutral protease 30 U / g 251.28 92.54 13.10 Cellulase 20 U / g + Neutral protease 30 U / g 541.75 136.47 23.44 Cellulase 50U / g 488.23 143.58 20.98 Neutral protease 50 U / g 379.50 118.32 23.01 Cellulase 20 U / g + neutral protease 30 U / g + ultrasound 709.67 152.64 28.07

[0037] The data in Table 3 show that the enzymatic method combined with ultrasound-assisted operation can make the active ingredients in peony pollen dissolve more fully.

[0038] Example 3 This example focuses on exploring the interception effect of ultrafiltration membranes of different specifications on peony extract, and the specific experimental operation is as follows: (1) Take fresh peony flowers, precool them at -18°C for 5 h, and then deep freeze them at -50°C for 5 h. Take the frozen peony flowers and shear and crush them in a circulating liquid nitrogen atmosphere. The liquid nitrogen temperature in the chamber and pipeline of the crushing equipment is -50°C. Sieve the powder to obtain peony flower full micronized powder with a particle size of less than 50 μm. (2) Take the peony flower powder obtained in (1), add citric acid buffer at a material-liquid mass ratio of 1:5, and adjust the pH value of the mixed solution to 6.0, and use a composite enzyme to hydrolyze at room temperature for 2 h. During the enzymatic hydrolysis, ultrasonic treatment is performed twice, each ultrasonic treatment is performed for 0.5 h and then ultrasonic treatment is performed again after an interval of 0.5 h. The ultrasonic frequency is 40 kHz to obtain an enzymatic hydrolyzate; In the complex enzyme, the addition amount of cellulase and neutral protease was 20 U / g and 30 U / g dry basis peony flower whole micro powder weight, respectively; (3) The enzymatic hydrolysate obtained in (2) was centrifuged at a speed of 8000 rpm for 10 min at 4°C. The supernatant was retained and filtered using ultrafiltration membranes of different specifications (unretained, 3000 Da, 6000 Da, and 10000 Da) to obtain a product enrichment solution.

[0039] The activity effects of peony extract concentrated stock solution obtained by ultrafiltration membranes of different specifications are shown in Table 4 below.

[0040] Table 4 Activity of enriched fractions with different molecular weights

[0041] The above results show that peony flower concentrated stock solutions of different molecular weights have high biological activity. Even for the stock solution without interception operation, its tyrosinase inhibition rate, cell melanin production inhibition rate, and cell secretion of TNF-α inhibition rate are all above 52%. When the stock solution is intercepted by ultrafiltration membrane, the activity of the peony flower concentrated stock solution with a specific molecular weight obtained is improved compared with the stock solution, especially the component with a molecular weight interception of ≤6 kDa, whose tyrosinase inhibition rate is 39.9% higher than that of the stock solution.

[0042] Example 4 A method for preparing a concentrated peony flower liquid rich in aroma components comprises the following steps: (1) Take fresh peony flowers, precool them at -18°C for 5 h, and then deep freeze them at -50°C for 5 h. Take the frozen peony flowers and shear and crush them in a circulating liquid nitrogen atmosphere. The liquid nitrogen temperature in the chamber and pipeline of the crushing equipment is -50°C. Sieve the powder to obtain peony flower full micronized powder with a particle size of less than 50 μm. (2) Take the peony flower powder obtained in (1), add citric acid buffer at a material-liquid mass ratio of 1:5, and adjust the pH value of the mixed solution to 6.0, and use a composite enzyme to hydrolyze at room temperature for 2 h. During the enzymatic hydrolysis, ultrasonic treatment is performed twice, each ultrasonic treatment is performed for 0.5 h and then ultrasonic treatment is performed again after an interval of 0.5 h. The ultrasonic frequency is 40 kHz to obtain an enzymatic hydrolyzate; In the complex enzyme, the addition amount of cellulase and neutral protease was 20 U / g and 30 U / g dry basis peony flower whole micro powder weight, respectively; (3) The enzymatic hydrolysate obtained in (2) was subjected to high-speed refrigerated centrifugation at a speed of 8000 rpm, a centrifugation time of 10 min, and a temperature of 4°C. The supernatant was retained and ultrafiltered using an ultrafiltration membrane to retain components with a molecular weight of ≤6 kDa to obtain a product enrichment solution; (4) The product enriched liquid obtained in (3) is subjected to low-temperature vacuum film concentration at an evaporation temperature of ≤50°C, and concentrated to 1 / 5 of the volume of the enriched liquid. Citric acid buffer is then added to adjust the pH value to 5.5, and the mixture is sterilized at 80°C for 25 min and filtered to obtain a peony flower concentrated stock solution rich in aroma components.

[0043] The activity of the concentrated peony flower solution rich in aroma components prepared in this example was tested, and the inhibition of the concentrated peony flower solution rich in aroma components on tyrosinase activity, melanin synthesis of B16F10 cells, and TNF-α secretion of RAW264.7 cells at different concentrations was measured. The results are shown in the attached Figure 1-3 .

[0044] The results of the inhibition rate of tyrosinase activity of the peony flower concentrated liquid rich in aroma components are shown in the attached figure. Figure 1 shown.

[0045] From the data in the figure, it can be seen that different concentrations of peony flower concentrates rich in aroma components have the effect of inhibiting tyrosinase activity, and are concentration-dependent. When the drug concentration is 6.25~800μg / mL, the inhibitory effect of the drug on tyrosinase is dose-dependent and increases with the increase of drug concentration. According to the fitting curve (y=-7×10 -5 x 2 +0.1007x+16.587, R 2 =0.9988) we can get the IC value of peony flower extract. 50 It is 640.3μg / mL.

[0046] The inhibition of the obtained peony flower concentrated liquid rich in aroma components on the melanin synthesis of B16F10 cells is shown in the attached Figure 2 shown.

[0047] The experimental results showed that when the concentration of peony flower concentrated solution rich in aroma components was 6.25 μg / mL, 12.5 μg / mL, 25 μg / mL, 50 μg / mL, 100 μg / mL, 200 μg / mL, 400 μg / mL, and 800 μg / mL, the inhibition rates on cellular melanin synthesis were 0.79±1.32%, 2.06±1.15%, 5.32±1.78%, 13.39±1.36% (P<0.01), 25.73±1.13% (P<0.0001), 32.23±0.82% (P<0.0001), 42.33±0.95% (P<0.0001), and 52.94±1.42% (P<0.0001), respectively.

[0048] It is not difficult to see from the experimental results that the peony flower concentrated stock solution rich in aroma components obtained by the method of the present invention has an inhibitory effect on the melanin production of B16F10 cells at a certain concentration and is concentration-dependent.

[0049] The inhibitory effect of the obtained peony flower concentrated liquid rich in aroma components on the secretion of TNF-α by RAW264.7 cells is shown in the attached Figure 3 shown.

[0050] The results showed that when the concentration of the peony flower concentrated solution rich in aroma components was 6.25 μg / mL, 12.5 μg / mL, 25 μg / mL, 50 μg / mL, 100 μg / mL, 200 When the concentrations of 400μg / mL, 400μg / mL and 800μg / mL were respectively, the inhibition rates on TNF-α secretion of cells were 5.08±0.75%, 12.46±0.54% (P<0.001), 19.83±1.74% (P<0.001), 24.93±1.73% (P<0.001), 40.02±0.98% (P<0.0001), 46.52±0.92% (P<0.0001), 54.68±0.85% (P<0.0001) and 62.28±1.03% (P<0.0001).

[0051] The above results show that the peony flower extract rich in aroma components has an inhibitory effect on the secretion of TNF-α by RAW264.7 cells at a certain concentration, and is concentration-dependent.

[0052] Comparative Example 1 A peony flower concentrated stock solution was prepared by supercritical fluid method, and the specific experimental operation was as follows: Supercritical carbon dioxide fluid was used to extract peony flower stock solution: the specific operating parameters were extraction pressure 30 MPa, extraction temperature 55°C; separator I pressure 8 MPa, separator I temperature 65°C; separator II pressure 8 MPa, separator II temperature 20°C.

[0053] Comparative Example 2 A peony flower concentrated stock solution was prepared by double enzyme digestion method, and the specific experimental operation was as follows: Peony flowers were taken as raw materials, citric acid buffer was added in a mass-to-volume ratio of 1:5, the pH value of the mixed solution was adjusted to 6.0, composite enzyme was added for enzymolysis at room temperature for 2 h, the added amounts of cellulase and neutral protease were 20 U / g and 30 U / g of dry basis peony flower whole micro powder weight, respectively; the enzymolysis solution was sterilized at 80°C for 25 min, filtered, and the product enrichment solution was concentrated by low-temperature vacuum membrane concentration at an evaporation temperature of ≤50°C to 1 / 5 of the volume of the enrichment solution, thus obtaining peony flower concentrated stock solution.

[0054] Comparative Example 3 A peony flower concentrated liquid was prepared by conventional atmospheric distillation method. The specific experimental operation is as follows: The peony flower raw material was boiled and refluxed with 5 times distilled water for 2 hours, and then filtered after standing to room temperature. The filtrate was concentrated to 1 / 5 of the original volume at a temperature of 70-85°C to obtain the peony flower concentrated stock solution.

[0055] Comparative Example 4 A peony flower concentrated stock solution was prepared by rotary evaporation. The specific experimental operation was as follows: Fresh peony flowers were subjected to reduced pressure distillation in a rotary evaporator, with distilled water as the extraction solvent, a solid-liquid ratio of 1:5, and reduced pressure distillation for 2 h, a rotation speed of 60 rpm, a vacuum degree of -0.09 MPa, and a temperature of 90°C. After the reduced pressure distillation was completed, a peony flower extract was collected; the extract was subjected to low-temperature vacuum film concentration, with an evaporation temperature of ≤50°C, and concentrated to 1 / 5 of the volume of the enriched liquid, to obtain a peony flower concentrated stock solution.

[0056] The components in the peony flower concentrated liquid obtained by different methods were detected, and the content of each component in the products obtained by different methods is shown in Table 5 below.

[0057] Table 5 Comparison of components of peony flower concentrated solution obtained by different methods Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Total polyphenols / mg / g 133.87 121.98 99.54 25.23 33.78 Total flavonoids / mg / g 25.79 27.23 18.43 4.79 8.76 Linalool oxide / % 7.78 7.33 5.67 5.56 6.35 Citronellol / % 1.23 0.84 0.56 1.39 1.05 Geraniol / % 0.93 0.57 0.42 1.83 1.24 Benzoic acid / % 0.77 0.80 0.62 0.69 0.73 Vc / mg / 100g 223 163 152 37 52 Gallic acid / mg / 100g 406 379 325 232 273 Flavonoid glycosides / mg / 100g 1324 879 1024 573 732

[0058] The results in Table 5 show that the peony flower concentrated solutions prepared by different methods all contain the above-mentioned active ingredients, but the contents of the active ingredients show great differences. Among them, the concentrated solution obtained by the traditional atmospheric distillation method has the lowest active ingredient content, which may be caused by the destruction of the active substances due to the high temperature. The concentrated solution obtained by the method of the present invention has much higher contents of total polyphenols, total flavonoids, main aroma substances (measured in terms of oxidized linalool, citronellol, geraniol and benzoic acid) than the peony flower concentrated solutions obtained by other methods.

[0059] Experimental Example 1 This experimental example focuses on verifying the effect of adding the product stability enhancer provided by the present invention. The specific experimental operation is as follows: First, a peony flower concentrated stock solution rich in aroma components is obtained according to the method in Example 4, and then a product stability enhancer is added to the obtained peony flower concentrated stock solution rich in aroma components, and after stirring evenly, a product containing a peony flower concentrated stock solution rich in aroma components is obtained.

[0060] The stability enhancer used in this product is prepared by the following method: Add 20 mL of peony seed oil, 5 g of sodium lactate, and 100 mL of water into the reaction tank, stir and heat to 70°C, then add 0.6 g of ε-polylysine hydrochloride and 3 g of methyl hydroxybenzoate, stir and then add citric acid buffer, adjust the pH to 5.5, then add 20 g of chitosan, stir evenly, and cool to room temperature.

[0061] The product containing the concentrated peony flower liquid rich in aroma components prepared in this experimental example and the concentrated peony flower liquid obtained by the method in Comparative Examples 1-4 were placed at room temperature for 1 month, and the stability of each concentrated peony flower liquid was compared. The turbidity of the products after being placed is shown in the attached figure. Figure 4 shown.

[0062] Attached Figure 4 In the figure, a is a picture of the product prepared in Experimental Example 1; bg are pictures of different products after being placed at room temperature for 1 month, specifically: b-product of Experimental Example 1, c-product of Example 4; d-product of Comparative Example 1; e-product of Comparative Example 2; f-product of Comparative Example 3; g-product of Comparative Example 4.

[0063] From the attached Figure 4 As can be seen from a and b, the product obtained by adding the product stability enhancer provided by the present invention to the prepared peony flower concentrated stock solution rich in aroma components, i.e., the product in Experimental Example 1, has good clarity and color after being placed at room temperature for 1 month; the clarity of the product without adding the stability enhancer is slightly reduced, as shown in c. It can be seen that the addition of the product stability enhancer provided by the present invention has a good effect on maintaining the stability of the product.

[0064] In addition, as shown in Figure dg, the peony flower concentrated liquid product prepared by the method of Comparative Examples 1-4 has obvious browning and significantly reduced clarity after being placed at room temperature for one month.

[0065] Experimental Example 2-10 In order to further verify the effect of the product stability enhancer provided by the present invention, the inventors also conducted the following experiments: The difference from Experimental Example 1 is that the composition of the stability enhancer is different. Other conditions remain unchanged. The browning degree and turbidity increase rate of the product after storage at room temperature for 1 month are shown in Table 6 below.

[0066] Table 6 Stability of the product after storage at room temperature for 1 month Peony seed oil / mL Sodium lactate / g ε-Polylysine hydrochloride / g Methyl hydroxybenzoate / g Chitosan / g Browning degree increase rate / % Turbidity increase rate / % Experimental Example 2 30 4 0.5 2.5 15 0 0 Experimental Example 3 0 4 0.5 2.5 15 0.05 0.02 Experimental Example 4 50 4 0.5 2.5 15 0.08 0.17 Experimental Example 5 30 2 0.5 2.5 15 0.06 0.28 Experimental Example 6 30 6 0.5 2.5 15 0.07 0.06 Experimental Example 7 30 4 0.3 1.5 15 0.18 0.05 Experimental Example 8 30 4 0.7 3.5 15 0.01 0.10 Experimental Example 9 30 4 0.5 2.5 0 0.10 0.32 Experimental Example 10 30 4 0.5 2.5 30 0.06 0.04

[0067] Note 1: The browning degree is measured by a colorimeter, and the browning degree increase rate is expressed as: (the average of three results of the liquid products of Experimental Examples 3-10 - the measured value of Experimental Example 2) / the measured value of Experimental Example 2.

[0068] Note 2: Turbidity is measured by a turbidity meter, and the turbidity increase rate is expressed as: (average of three results of the liquid products of Experimental Examples 3-10 - measured value of Experimental Example 2) / measured value of Experimental Example 2.

[0069] The results in Table 6 show that the addition of the product stability enhancer provided by the present invention has a good stabilizing effect on the preservation of the peony flower liquid rich in aroma components, which is beneficial to prolonging the storage period of the peony flower liquid.

[0070] The peony flower concentrated stock solution of the present invention contains rich aroma components such as linalool oxide, citronellol, geraniol, benzoic acid, etc., and has a high flavonoid content. In addition, the flavonoids also contain a part of aroma components. Therefore, the peony flower stock solution with rich aroma components can be used in the preparation of products such as essences and spices. For example, the stock solution can be used in the preparation of essences and spices as a whole, or the aroma components can be further separated therefrom and mixed with other spices to prepare essences or spices with target aromas.

Claims

1. A method for preparing a concentrated peony flower liquid rich in aroma components, characterized in that: The steps include: (1) Take fresh peony flowers, precool them at -20~-18℃ for 4~6 h, and then deep freeze them at -55~-45℃ for 4~6 h. Take the frozen peony flowers and shear and crush them in a circulating liquid nitrogen atmosphere. The liquid nitrogen temperature in the cavity and pipeline of the crushing equipment is -55~-45℃. Sieve the powder to obtain peony flower full micronized powder with a particle size of less than 50 μm. (2) taking the peony flower whole powder obtained in (1), adding a complex enzyme and performing enzymolysis under ultrasonication to obtain an enzymolysis solution; Based on the weight of dry peony flower powder, the addition amount of cellulase and neutral protease in the complex enzyme is 20-30 U / g and 20-50 U / g respectively; (3) centrifuging the enzymatic hydrolysate obtained in (2), retaining the supernatant, and filtering the supernatant using an ultrafiltration membrane to obtain a product enriched solution; (4) The product enriched liquid obtained in (3) is subjected to low-temperature vacuum film concentration, sterilization, and filtration to obtain a peony flower concentrated stock solution rich in aroma components.

2. The preparation method according to claim 1, characterized in that (2) Before using the composite enzyme for enzymatic hydrolysis, citric acid buffer was added at a material-liquid mass ratio of 1:4-6, and the pH value of the mixed solution was adjusted to 5.5-6.

5. The composite enzyme was used for enzymatic hydrolysis at room temperature for 1-3 h. Ultrasonic treatment was performed 1-3 times during the enzymatic hydrolysis process. Each ultrasonic treatment was performed for 0.5 h and then another ultrasonic treatment was performed at an interval of 0.5 h. The ultrasonic power was 20-50 kHz.

3. The preparation method according to claim 1, characterized in that: The refrigerated centrifugation described in (3) has a centrifugal speed of 8000-10000 rpm, a centrifugal time of 10-15 min, and a temperature of 0-4°C.

4. The preparation method according to claim 1, characterized in that: (3) The supernatant is retained by an ultrafiltration membrane to obtain a product enriched solution with a molecular weight cutoff of less than 6000 Da.

5. The preparation method according to claim 1, characterized in that: The low temperature vacuum film concentration described in (4) is carried out at an evaporation temperature of ≤50°C, and the concentrate is concentrated to 1 / 4 to 1 / 6 of the volume of the enriched liquid, and then a citric acid buffer is added to adjust the pH value to 5.5 to 6.

0.

6. The preparation method according to claim 1, characterized in that: The sterilization temperature described in (4) is 65~85℃, and the sterilization time is 15~30 min.

7. A product containing the peony flower concentrated liquid rich in aroma components as claimed in claim 1, characterized in that: The product is obtained by adding a product stability enhancer to the peony flower concentrated liquid rich in aroma components obtained in (4) and stirring the mixture evenly, wherein 2 to 5 g of the product stability enhancer is added to every 100 mL of the peony flower concentrated liquid rich in aroma components.

8. The product according to claim 7, characterized in that The product stability enhancer is prepared by the following method: Add 20-40 mL of peony seed oil, 3-5 g of sodium lactate, and 100 mL of water into a reaction tank, stir and heat to 60-80°C, then add 0.4-0.6 g of ε-polylysine hydrochloride and 2-3 g of methyl hydroxybenzoate, stir and then add citric acid buffer, adjust the pH to 5.5-6.0, then add 10-20 g of chitosan, stir evenly, and cool to room temperature to obtain a stability enhancer.

9. Use of the peony flower concentrated liquid rich in aroma components as claimed in claim 1 or the product as claimed in claim 7 in skin care products.

10. Use of the peony flower concentrated liquid rich in aroma components as claimed in claim 1 or the product as claimed in claim 7 in flavors / spices.

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