Method for preparing a fresh flower concentrate stock solution

Abstract

This application relates to a method for preparing concentrated flower extract, belonging to the field of flower extraction technology. The method includes the following steps: (1) placing fresh flowers in an environment of 20±2℃, and subjecting the relative humidity of the environment to four stages of humidity shaking treatment at 75%±4%, 45%±5%, 75%±5%, and 15%±2% respectively, each stage lasting 120-480 minutes, with a humidity change rate of 15-20% / h; (2) pulping the flowers after humidity shaking treatment to obtain a pulping liquid; (3) adding 4-6 times the amount of citrate buffer to the pulping liquid, then adding an enzyme to the citrate buffer and performing enzymatic hydrolysis under ultrasonication to obtain an enzymatic hydrolysate; (4) filtering the enzymatic hydrolysate, and then concentrating the filtrate under low-temperature vacuum membrane, sterilizing, and filtering to obtain concentrated flower extract. In this application, based on the existing double-enzyme method, the secondary humidity shaking treatment of the flowers can significantly promote the full release of active substances in the flowers.

Description

Technical Field

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

[0002] As the essence of plants, flowers are valued not only for their ornamental value but also for their edible and medicinal properties. In addition to rich nutrients such as proteins, amino acids, lipids, sugars, vitamins, and minerals, flowers also contain bioactive substances such as polyphenols and flavonoids. The antioxidant activity of these polyphenols and flavonoids has long been a major focus of research on the functional properties of flowers.

[0003] In the extraction process of fresh flowers, pulping or crushing is often required before further processing. However, due to the softness of flower petals, they easily clump together and become a paste during crushing, making it difficult to fully dissolve the active ingredients. Existing techniques involve freezing the fresh flowers at low temperatures (≤-20℃) to make them brittle, followed by crushing, which is believed to improve the dissolution of intracellular active ingredients. While this method can improve the dissolution of effective components to some extent, the freezing process causes water within the flower cells to form ice crystals, which puncture cell membranes and vacuolar membranes. This leads to direct contact between cell contents (such as polyphenols and anthocyanins) and oxidases (such as PPO and POD), triggering enzymatic browning. Furthermore, the method of freezing followed by crushing is also quite cumbersome.

[0004] Simplifying extraction procedures and increasing the content of active ingredients in the extract has always been a goal pursued by those skilled in the art. Summary of the Invention

[0005] To address or partially address the problems existing in related technologies, this application provides a method for preparing concentrated flower extract.

[0006] A method for preparing concentrated flower extract according to this application includes the following steps:

[0007] (1) Place fresh flowers in an environment of 20±2℃, and subject the relative humidity of the environment to four stages of humidity shaking treatment at 75%±4%, 45%±5%, 75%±5%, and 15%±2%, with each stage lasting 90-120 minutes.

[0008] (2) The fresh flowers that have undergone humidity shaking treatment are pulped to obtain pulp liquid;

[0009] (3) Add 4-6 times the amount of citrate buffer to the pulping solution. The temperature of the citrate buffer is 4℃±0.5℃ and the pH is 3.80±0.1. Then add the enzyme to the citrate buffer and perform enzymatic hydrolysis under the action of ultrasound to obtain the enzymatic hydrolysate.

[0010] (4) After the enzymatic hydrolysate is filtered, the filtrate is concentrated by low temperature vacuum membrane, sterilized, and filtered to obtain concentrated fresh flower solution.

[0011] Furthermore, in step (1), the relative humidity of the environment is subjected to a four-stage humidity oscillation process at 75%, 45%, 75%, and 15% respectively.

[0012] In this application, the reason for choosing 75%RH as the starting point during humidity oscillation treatment is that: below 70%RH, sufficient expansion is impossible, while above 80%RH, cell wall plastic deformation occurs. Meanwhile, the reason for choosing 45%RH as the trough is that: with a humidity interval of 30% between oscillation from 75%RH to 45%RH, a better microcrack generation effect can be achieved. Furthermore, a second 75%RH treatment is necessary; only by restoring to high humidity can crack propagation be achieved. The final 15%RH endpoint is chosen because at 15%RH, the lignin in the cell wall undergoes a glass transition (Tg=18℃), which solidifies the cracks, thus forming channels that facilitate the release of active substances.

[0013] Furthermore, the enzyme is a complex enzyme composed of cellulase and pectinase.

[0014] Further, the low-temperature vacuum thin-film concentration in step (4) specifically involves: evaporation temperature ≤ 50°C, and concentration to 1 / 4 to 1 / 6 of the volume of the enriched liquid.

[0015] The mechanism of this application is:

[0016] First, the fresh flowers are allowed to absorb water and swell in a high-humidity environment (75% RH), during which the cell walls stretch. Then, in a medium-humidity environment (45% RH), the cells dehydrate and shrink, causing microcracks to form, thus completing one round of cell water absorption and swelling. Next, the cells with microcracks absorb water again in a high-humidity environment (75% RH) and undergo a second swelling. After the second swelling, the microcracks formed earlier are further enlarged. Finally, in a low-humidity environment (15% RH), ultimate dehydration is achieved, causing the cell wall cellulose microfibers to break down and form permanent channels that facilitate the release of active substances. This is then combined with subsequent low-temperature extraction to achieve low-damage and efficient release of components. Figure 1 The diagram shown illustrates the technical principle of the method in this application.

[0017] The addition of low-temperature citrate buffer can, on the one hand, target and inhibit the activity of PPO / POD enzymes. Polyphenol oxidase (PPO) is most suitable at pH 6.5-7.0, and its activity is lost by more than 99% at pH 3.8. Peroxidase (POD) is conformationally unstable at pH < 4.2. On the other hand, the acidic environment can fix cell wall channels. At 4°C, cell membrane phospholipids change from a liquid crystal state to a gel state, reducing membrane fluidity and preventing the channels from repairing themselves, thus facilitating the passage and release of active substances.

[0018] The beneficial effects of this application are:

[0019] 1. In this application, based on the existing dual-enzyme method, the second humidity shaking treatment of fresh flowers can significantly promote the full release of active substances in the flowers.

[0020] 2. The humidity vibration treatment in this application is more convenient than the existing method of freezing flowers at low temperature, making them brittle, and then crushing them.

[0021] 3. The concentrated flower extract prepared by the method in this application contains a high content of total polyphenols and total flavonoids and has a rich aroma, so it can be used in the production of fragrances, perfumes and cosmetics. Attached Figure Description

[0022] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0023] Figure 1 This is a schematic diagram illustrating the technical principles of the method in this application. Detailed Implementation

[0024] The embodiments of this application will now be described in more detail with reference to the examples. While embodiments of this application are shown in the examples, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art. Example 1

[0025] A method for preparing concentrated peony flower extract according to this application includes the following steps:

[0026] (1) Take fresh peony flowers and place them in an environment of 20±2℃. The relative humidity of the environment where the peony flowers are located is subjected to four stages of humidity fluctuation treatment at 75%, 45%, 75% and 15% respectively. The first three stages are each 120min, and the last stage is 240min. The humidity change rate is 15-20% / h.

[0027] (2) The peony flowers that have undergone humidity shaking treatment are pulped to obtain pulp liquid;

[0028] (3) Add 5 times the amount of citrate buffer to the pulping solution. The temperature of the citrate buffer is 4℃ and the pH is 3.80±0.1. Then add pectinase and cellulase to the resulting mixture. The amount of pectinase added is 0.3g per kg of mixture, and the amount of cellulase added is 0.5g per kg of mixture. Then perform enzymatic hydrolysis under ultrasonic treatment for 1h at an ultrasonic frequency of 40 kHz to obtain the enzymatic hydrolysate.

[0029] (4) After the enzymatic hydrolysate is filtered, the filtrate is concentrated by low temperature vacuum membrane, sterilized, and filtered to obtain peony flower concentrate; wherein, the low temperature vacuum membrane concentration is specifically: evaporation temperature 50°C, concentrated to one-fifth of the volume of the enriched liquid; the sterilization operation is sterilization at 85°C for 15 min. Example 2

[0030] A method for preparing concentrated red rose petal extract according to this application includes the following steps:

[0031] (1) Take fresh red roses and place them in an environment of 20±2℃. The relative humidity of the environment where the red roses are located is subjected to four stages of humidity shaking treatment, namely 75%, 45%, 75% and 15%, and each stage is maintained for 120 minutes.

[0032] (2) The red rose petals that have undergone humidity shaking treatment are pulped to obtain pulp liquid;

[0033] (3) Add 4 times the amount of citrate buffer to the pulping solution. The temperature of the citrate buffer is 4℃ and the pH is 3.80±0.1. Then add pectinase and cellulase to the resulting mixture. The amount of pectinase added is 0.4g per kg of mixture, and the amount of cellulase added is 0.4g per kg of mixture. Then perform enzymatic hydrolysis for 1.5h under ultrasonic treatment. The ultrasonic frequency is 35 kHz to obtain the enzymatic hydrolysate.

[0034] (4) After the enzymatic hydrolysate is filtered, the filtrate is concentrated by low temperature vacuum membrane, sterilized, and filtered to obtain the concentrated red rose petal stock solution; wherein, the low temperature vacuum membrane concentration is specifically: evaporation temperature 48°C, concentrated to one-fifth of the volume of the enriched liquid; the sterilization operation is sterilization at 80°C for 25 minutes. Example 3

[0035] A method for preparing concentrated rose extract according to this application includes the following steps:

[0036] (1) Take fresh roses and place them in an environment of 20±2℃. The relative humidity of the environment where the roses are located is subjected to four stages of humidity shaking treatment, namely 71%, 41%, 70% and 13%, and each stage is maintained for 120 minutes.

[0037] (2) The rose petals that have undergone humidity shaking treatment are pulped to obtain pulp liquid;

[0038] (3) Add 6 times the amount of citrate buffer to the pulping solution. The temperature of the citrate buffer is 4℃ and the pH is 3.80±0.1. Then add pectinase and cellulase to the resulting mixture. The amount of pectinase added is 0.4g per kg of mixture, and the amount of cellulase added is 0.5g per kg of mixture. Then perform enzymatic hydrolysis under ultrasonic treatment for 1h at an ultrasonic frequency of 40 kHz to obtain the enzymatic hydrolysate.

[0039] (4) After the enzymatic hydrolysate is filtered, the filtrate is concentrated by low temperature vacuum membrane, sterilized, and filtered to obtain the concentrated original solution of rose; wherein, the low temperature vacuum membrane concentration is specifically: evaporation temperature 50°C, concentrated to one-fifth of the volume of the enriched liquid; the sterilization operation is sterilization at 85°C for 15 min. Example 4

[0040] A method for preparing concentrated peony extract according to this application includes the following steps:

[0041] (1) Take fresh peony and place it in an environment of 20±2℃. The relative humidity of the environment where the peony is located is subjected to four stages of humidity shaking treatment at 75%, 45%, 75% and 15% respectively, and each stage is maintained for 120 minutes.

[0042] (2) The peony root that has been subjected to humidity shaking treatment is pulped to obtain pulp liquid;

[0043] (3) Add 5 times the amount of citrate buffer to the pulping solution. The temperature of the citrate buffer is 4℃ and the pH is 3.80±0.1. Then add pectinase and cellulase to the resulting mixture. The amount of pectinase added is 0.3g per kg of mixture, and the amount of cellulase added is 0.5g per kg of mixture. Then perform enzymatic hydrolysis under ultrasonic treatment for 1h at an ultrasonic frequency of 40 kHz to obtain the enzymatic hydrolysate.

[0044] (4) After the enzymatic hydrolysate is filtered, the filtrate is concentrated by low temperature vacuum membrane, sterilized, and filtered to obtain peony concentrate; wherein, the low temperature vacuum membrane concentration is specifically: evaporation temperature 50°C, concentrated to one-fifth of the volume of the enriched liquid; the sterilization operation is sterilization at 85°C for 15 min.

[0045] Comparative Example 1

[0046] The difference between the comparative example and Example 1 is that in step (1) of the comparative example, only the relative humidity of the environment where the peony flower is located is subjected to two stages of humidity oscillation treatment at 75% and 45% respectively. The rest is the same as Example 1.

[0047] Comparative Example 2

[0048] The difference between the comparative example and Example 1 is that in step (1) of the comparative example, only the relative humidity of the environment where the peony flower is located is subjected to two stages of humidity oscillation treatment at 45% and 75% respectively. The rest is the same as Example 1.

[0049] Comparative Example 3

[0050] In Comparative Example 3, the conventional two-enzyme method was used to extract concentrated peony flower extract. The difference between Comparative Example 3 and Example 1 is that the peony flowers were not subjected to humidity shaking treatment before pulping. All other aspects were the same.

[0051] Comparative Example 4

[0052] Comparative Example 4 uses the conventional dual-enzyme method to extract concentrated rose petal extract. The difference between Comparative Example 4 and Example 2 is that the rose petals were not subjected to humidity shaking treatment before pulping. All other aspects are the same.

[0053] Comparative Example 5

[0054] Comparative Example 5 uses the conventional dual-enzyme method to extract concentrated rose petal extract. The difference between Comparative Example 5 and Example 3 is that the rose petals were not subjected to humidity shaking treatment before pulping. All other aspects are the same.

[0055] Comparative Example 6

[0056] Comparative Example 6 uses the conventional dual-enzyme method to extract concentrated peony extract. The difference between Comparative Example 6 and Example 4 is that the peony was not subjected to humidity shaking treatment before pulping. All other aspects are the same.

[0057] The total polyphenol and total flavonoid contents of the concentrated flower extracts prepared in the examples and comparative examples were determined. Specifically, the total polyphenol content was determined using the ferric tartrate method; the total flavonoid content was determined using the NaNO2-Al(NO3)3 colorimetric method. All results were tested three times, and the average value was taken. It should be noted that the above determination methods are all conventional detection methods commonly used in the art, and therefore, the applicant will not elaborate further here. The test results are shown in Table 1 below;

[0058] Table 1. Total polyphenol and total flavonoid content of the concentrated flower extracts obtained in the examples and comparative examples.

[0059]

[0060] As can be seen from the results in Table 1, the concentrated flower extracts prepared using the method described in this application in Examples 1-4, when applied to various types of flowers, showed significantly better extraction results in both total polyphenol and total flavonoid content compared to the concentrated flower extracts obtained using the conventional dual-enzyme method in Comparative Examples 3-6. This indicates that subjecting the flowers to a humidity gradient agitation before processing them using the dual-enzyme method can effectively promote the release of active ingredients from the flower cells.

[0061] As can be seen from the results of Example 1 and Comparative Example 1, simply performing a positive humidity shaking treatment on the flowers, i.e., reducing the humidity from 75% to 45%, can also promote the release of active ingredients in the flower cells, compared to the dual-enzyme method. However, since a secondary humidity shaking treatment was not performed to promote crack expansion and channel solidification, the improvement effect was not significant.

[0062] As can be seen from the results of Example 1 and Comparative Example 2, simply performing a reverse humidity shaking treatment on the flowers, i.e., changing the humidity from 45% to 75%, causes the flower cells to be in a state of water absorption and swelling before enzymatic hydrolysis. The results show that the release of total polyphenols and total flavonoids is basically the same as that of the dual-enzyme method, with no significant difference.

[0063] The above results fully demonstrate that, based on the existing two-enzyme method, a secondary humidity shaking treatment of fresh flowers can significantly promote the full release of active substances in the flowers.

[0064] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for preparing concentrated flower extract, characterized in that, Includes the following steps: (1) Place fresh flowers in an environment of 20±2℃, and subject the relative humidity of the environment to four stages of humidity fluctuation treatment at 75%±4%, 45%±5%, 75%±5%, and 15%±2%, with each stage lasting 120-480 minutes and the humidity change rate being 15-20% / h. (2) The fresh flowers that have undergone humidity shaking treatment are pulped to obtain pulp liquid; (3) Add 4-6 times the amount of citrate buffer to the pulping solution. The temperature of the citrate buffer is 4℃±0.5℃ and the pH is 3.80±0.

1. Then add the enzyme to the citrate buffer and perform enzymatic hydrolysis under the action of ultrasound to obtain the enzymatic hydrolysate. (4) After the enzymatic hydrolysate is filtered, the filtrate is concentrated by low temperature vacuum membrane, sterilized, and filtered to obtain concentrated fresh flower solution.

2. The method for preparing concentrated flower extract according to claim 1, characterized in that, In step (1), the relative humidity of the environment is subjected to a four-stage humidity oscillation process at 75%, 45%, 75%, and 15% respectively.

3. The method for preparing concentrated flower extract according to claim 1, characterized in that, The enzyme is a complex enzyme composed of cellulase and pectinase.

4. The method for preparing concentrated flower extract according to claim 1, characterized in that, The low-temperature vacuum thin-film concentration in step (4) specifically involves: evaporation temperature ≤ 50°C, and concentration to 1 / 4 to 1 / 6 of the volume of the enriched liquid.

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