A method for preparing a low metal salt cistanche wine extract

Abstract

The present application relates to the technical field of extraction, and specifically provides a preparation method of low-metal salt cistanche wine extract, which specifically comprises the following steps: base wine extraction, concentration, ultrasonic-assisted sodium bicarbonate dissolution, multi-stage acid reaction, filtration and ceramic membrane impurity removal, dynamic high-pressure microfluidization treatment, and drying, and the like, so as to prepare the low-metal salt cistanche wine extract. The preparation method is simple and green, and no organic solvent is used in the whole process. The cistanche extract obtained by the method has low metal salt content, significantly reduced bitterness value, high color stability in the wine body, convenient industrial production, and good market value.

Description

Technical Field

[0001] The invention relates to the technical field of extraction, in particular to a method for preparing a low-metal salt Cistanche deserticola wine extract. Background Art

[0002] Cistanche deserticola is the dried, scaly-leaved fleshy stem of the Orobanchaceae plant Cistanche deserticola or Cistanche tubulosa. It is widely cultivated in my country's Inner Mongolia, Gansu, Xinjiang, and Qinghai provinces. It is a dual-purpose medicinal plant, often used to boost kidney yang and promote bowel movements. There are also reports of its use in health wines to boost immunity. Cistanche deserticola contains numerous nutrients, and modern pharmacological research indicates that its primary active ingredients are phenylethanoid glycosides, polysaccharides, and iridoids, which possess potent antioxidant, immune-boosting, liver cell-protecting, and bowel-moistening properties.

[0003] Cistanche deserticola often grows in salinized sandy environments, resulting in a high metal salt content in the herb. This is especially true in Cistanche deserticola extracts obtained through the commonly used ethanol extraction and drying methods. Cistanche deserticola extracts are used in health wines to replenish kidney yang and boost yang energy. However, in practice, Cistanche deserticola extracts have been found to exhibit a strong bitterness, which, when added to wine, can affect the product's taste, making them difficult for some consumers to accept as health wines. Our previous research on the bitterness in Cistanche deserticola extracts revealed that the bitterness primarily stems from the active ingredient verbascoside and metal ions. Removing these metal ions is the most effective method for reducing the bitterness of Cistanche deserticola extracts. Patent CN109824738A discloses a method for desalting and decolorizing total oligosaccharides from Cistanche deserticola using a macroporous adsorption resin in series. This method targets total oligosaccharides. Furthermore, our research team used the method described in patent CN109824738A to decolorize Cistanche deserticola extract using a series of macroporous adsorption resins. The results revealed a low retention rate of the main active ingredients, verbascoside and echinacoside, in the Cistanche deserticola extract. The extract's primary components are polysaccharides, with a high loss rate of phenylethanoid glycosides. Furthermore, patent CN109824738A primarily utilizes macroporous adsorption resins for desalting and decolorization, which can result in high levels of chemical residues and potentially lead to the production of high levels of harmful substances in the total oligosaccharides. Summary of the Invention

[0004] In view of this, the present invention proposes a method for preparing a Cistanche deserticola extract for wine, which can effectively reduce the metal salt content. The Cistanche deserticola extract for wine prepared by this method has a high metal salt removal rate, low bitterness value, and high chromaticity stability and effective ingredient retention rate.

[0005] The technical solution of the present invention is achieved as follows: The present invention provides a method for preparing a low-metal salt Cistanche deserticola wine extract, comprising the following steps:

[0006] Step 1: mixing the Cistanche deserticola with the base wine, heating and refluxing the mixture, and performing solid-liquid separation to obtain an extract;

[0007] Step 2: vacuum concentrating the extract to obtain a concentrated solution;

[0008] Step 3: Mix the concentrated solution with sodium bicarbonate and dissolve it under ultrasonication;

[0009] Step 4: Mix the concentrated solution containing sodium bicarbonate with dilute hydrochloric acid and stir until there are no bubbles, then add the oxalic acid solution and stir;

[0010] Step 5: Pass the solution obtained in step 4 through a filter bag to collect the permeate, and then pass it through a ceramic membrane to obtain the ceramic membrane permeate;

[0011] Step 6: subjecting the ceramic membrane permeate to dynamic high-pressure microfluidization treatment to obtain a Cistanche deserticola effluent;

[0012] Step 7: Dry the Cistanche deserticola effluent under vacuum at low temperature to obtain a low-metal salt Cistanche deserticola wine extract.

[0013] In some embodiments, in step 1, the base wine concentration is 40-80% vol, and the multiple of the base wine is 4-6 times.

[0014] In some embodiments, in step 1, the temperature of the heating reflux extraction is 50-85° C., the extraction time is 1-3 hours, and the reflux extraction method is condensation reflux extraction or dynamic circulation extraction.

[0015] In some embodiments, in step 2, the concentration temperature is 40-55° C., and the concentration endpoint is 1 / 3-1 / 4 of the original volume.

[0016] In some embodiments, in step three, the amount of sodium bicarbonate added is 0.5%-1% of the mass of the Cistanche deserticola concentrate, the ultrasonic power is 120-180W, and the ultrasonic temperature is 40-55°C.

[0017] In some embodiments, in step 4, the amount of dilute hydrochloric acid added is 0.5%-1% of the volume of the Cistanche deserticola concentrate.

[0018] In some embodiments, in step 4, the amount of oxalic acid added is 0.1%-0.5% of the mass of the Cistanche deserticola concentrate, the stirring reaction time after adding oxalic acid is 2-10 hours, and the stirring speed is 50-100 rpm.

[0019] In some embodiments, in step five, the pore size of the filter bag is 200-300 mesh, and the pore size of the ceramic membrane is 50-150 nm.

[0020] In some embodiments, in step six, the dynamic high-pressure microfluidization treatment pressure is 60-170 MPa, and the number of cycles is 3-7 times.

[0021] In some embodiments, in step seven, the drying temperature of the Cistanche deserticola effluent is 40-60°C.

[0022] The present invention has the following beneficial effects compared to the prior art:

[0023] The present invention discloses a method for preparing a Cistanche deserticola extract. The resulting extract has a metal salt ion removal rate of ≥95% and a low bitterness. Compared to a Cistanche deserticola extract obtained by simple ethanol extraction and drying, the bitterness value is reduced by more than 80%. Furthermore, the resulting extract exhibits high color stability. The overall preparation process of the present invention is simple, does not use organic solvents, and has high industrial application value. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the present invention belong. If the definitions set forth in this section are contrary to or otherwise inconsistent with definitions set forth in the patents, patent applications, published patent applications, and other publications incorporated herein by reference, the definitions listed in this section take precedence over the definitions incorporated herein by reference.

[0026] Unless otherwise specified, the methods used in the following examples are conventional methods. The materials, reagents, and instruments used are conventional materials, reagents, and instruments in the art, unless otherwise specified, and can be obtained commercially by those skilled in the art.

[0027] When an amount, concentration or other value or parameter is expressed as a range, a preferred range or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any upper range limit or preferred value with any lower range limit or preferred value, regardless of whether the range is disclosed alone. For example, when a range "1 to 5" is disclosed, the described range should be interpreted as including the ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within the range. In the present specification and claims, range definitions may be combined and / or interchanged, and if not otherwise stated, such ranges include all subranges contained therein.

[0028] Example 1

[0029] This embodiment provides a method for preparing a low-metal salt Cistanche deserticola wine extract.

[0030] Prepared by the following method:

[0031] (1) 1 kg of crushed Cistanche deserticola powder was added to an extraction container containing 4 L of 40% vol base wine solution, and condensed and refluxed for 1 h at 50°C to obtain 3.85 L of Cistanche deserticola extract. The obtained Cistanche deserticola extract was vacuum concentrated to 1.28 L at 40°C, and then 6.4 g of sodium bicarbonate was added to the Cistanche deserticola concentrate. The sodium bicarbonate was ultrasonically dissolved using an ultrasonic instrument at an ultrasonic power of 120 W and an ultrasonic temperature of 40°C.

[0032] (2) Add 6 mL of 10% dilute hydrochloric acid solution to the Cistanche deserticola concentrate containing sodium bicarbonate, stir and react until no bubbles appear, then add 1.28 g of oxalic acid and stir at 50 r / min for 2 h. The obtained Cistanche deserticola concentrate is passed through a filter bag with a pore size of 200 mesh, and the permeate is collected and passed through a ceramic membrane with a pore size of 50 nm to obtain a ceramic membrane permeate. The ceramic membrane permeate is then subjected to dynamic high-pressure microfluidization treatment under a pressure of 60 MPa, and the treatment is circulated three times to obtain a Cistanche deserticola effluent. Finally, the Cistanche deserticola effluent is vacuum dried at 40°C to obtain 121 g of a low-metal salt Cistanche deserticola wine extract.

[0033] Example 2

[0034] This embodiment provides a method for preparing a low-metal salt Cistanche deserticola extract for wine.

[0035] Prepared by the following method:

[0036] (1) 1 kg of crushed Cistanche deserticola powder was added to an extraction container containing 5 L of 60% vol base wine solution, and condensed and refluxed for 1.5 h at 60° C. to obtain 4.86 L of Cistanche deserticola extract. The obtained Cistanche deserticola extract was vacuum concentrated to 1.38 L at 45° C., and then 8.3 g of sodium bicarbonate was added to the Cistanche deserticola concentrate. The sodium bicarbonate was ultrasonically dissolved using an ultrasonic instrument at an ultrasonic power of 140 W and an ultrasonic temperature of 45° C.

[0037] (2) Add 8.9 mL of 10% dilute hydrochloric acid solution to the Cistanche deserticola concentrate containing sodium bicarbonate, stir and react until no bubbles appear, then add 1.77 g of oxalic acid and stir at 80 r / min for 4 h. The obtained Cistanche deserticola concentrate is passed through a filter bag with a pore size of 250 mesh, and the permeate is collected and passed through a ceramic membrane with a pore size of 100 nm to obtain a ceramic membrane permeate. The ceramic membrane permeate is then subjected to dynamic high-pressure microfluidization treatment under a pressure of 100 MPa, and the Cistanche deserticola effluent is obtained after 5 cycles of treatment. Finally, the Cistanche deserticola effluent is vacuum dried at 45°C to obtain 125 g of a low-metal salt Cistanche deserticola wine extract.

[0038] Example 3

[0039] This embodiment provides a method for preparing a low-metal salt Cistanche deserticola extract for wine.

[0040] Prepared by the following method:

[0041] (1) 1 kg of crushed Cistanche deserticola powder was added to an extraction container containing 6 L of 80% vol base wine solution, and condensed and refluxed for 3 h at 85°C to obtain 5.85 L of Cistanche deserticola extract. The obtained Cistanche deserticola extract was vacuum concentrated to 1.47 L at 55°C, and then 13.2 g of sodium bicarbonate was added to the Cistanche deserticola concentrate. The sodium bicarbonate was ultrasonically dissolved using an ultrasonic instrument at an ultrasonic power of 180 W and an ultrasonic temperature of 55°C.

[0042] (2) 13.4 mL of 10% dilute hydrochloric acid solution was added to the Cistanche deserticola concentrate containing sodium bicarbonate, and the reaction was stirred until no bubbles appeared. Then, 7.35 g of oxalic acid was added and stirred at a speed of 100 r / min for 10 h. The obtained Cistanche deserticola concentrate was passed through a filter bag with a pore size of 300 mesh, and the permeate was collected and passed through a ceramic membrane with a pore size of 150 nm to obtain a ceramic membrane permeate. The ceramic membrane permeate was then subjected to dynamic high-pressure microfluidization treatment under a pressure of 170 MPa. After 7 cycles of treatment, a Cistanche deserticola effluent was obtained. Finally, the Cistanche deserticola effluent was vacuum dried at 60°C to obtain 132 g of a low-metal salt Cistanche deserticola wine extract.

[0043] Comparative Example 1

[0044] This comparative example maintained the same steps as Example 1, except that after vacuum concentration to 1.28 L, 6 mL of 10% dilute hydrochloric acid solution was directly added to the Cistanche deserticola concentrate without adding sodium bicarbonate or performing ultrasound-assisted dissolution, to obtain 110 g of Cistanche deserticola extract.

[0045] Comparative Example 2

[0046] This comparative example is the same as Example 1 in other steps, except that the Cistanche deserticola concentrate containing sodium bicarbonate is directly passed through a filter bag with a pore size of 200 mesh without adding dilute hydrochloric acid and oxalic acid, to obtain 114 g of Cistanche deserticola extract.

[0047] Comparative Example 3

[0048] This comparative example is the same as Example 1 in other steps except that the dynamic high-pressure microfluidization treatment is not performed after the ceramic membrane permeate is obtained. The ceramic membrane permeate is vacuum dried at 40° C. to obtain 123 g of Cistanche deserticola extract.

[0049] Calculation of salt rejection rate:

[0050] In the above examples and comparative examples, the Cistanche deserticola extract obtained after reflux extraction was dried, and the dried extract was used as a control group of the corresponding examples or comparative examples.

[0051] The extracts finally prepared in the Examples and Comparative Examples and the corresponding control group extracts were dissolved in the base wine used in the corresponding Examples or Comparative Examples to keep their concentrations consistent. The conductivity of each sample was measured using a conductivity meter, and the desalination rate of the Cistanche deserticola extracts in different Examples or Comparative Examples was calculated using the following formula:

[0052] Desalination rate = [(AB) / A] × 100%

[0053] Where:

[0054] A is the electrical conductivity of the Cistanche deserticola control group, ms / cm;

[0055] B is the electrical conductivity of the Cistanche deserticola extract finally obtained in the corresponding embodiment or comparative example of the control group, ms / cm.

[0056] The calculated results of the salt rejection rates of the different examples and comparative examples are shown in the following table:

[0057] Group Desalination rate / % Example 1 Control Group / Example 1 96.3±0.2 Example 2 Control Group / Example 2 95.8±0.7 Example 3 Control Group / Example 3 95.8±0.5 Comparative Example 1 Control Group / Comparative Example 1 43.7±0.4 Comparative Example 2 Control Group / Comparative Example 2 21.6±0.3 Comparative Example 3 Control Group / Comparative Example 3 96.2±0.4

[0058] As can be seen from the data in the above table, the salt removal rates of the samples in Examples 1-3 were significantly different from those in Comparative Examples 1-2, with the salt removal rates all exceeding 95%. This indicates that both the ultrasound-assisted sodium bicarbonate dissolution step and the multi-stage acid reaction step with dilute hydrochloric acid and oxalic acid significantly desalt the Cistanche deserticola extract. However, compared with the Cistanche deserticola sample obtained in Comparative Example 3, the salt removal rates of the samples in Examples 1-3 did not change significantly, indicating that the dynamic high-pressure microfluidization treatment had no significant effect on desalination.

[0059] Comparison of the impact of bitterness value:

[0060] In the above examples and comparative examples, the Cistanche deserticola extract obtained after reflux extraction was dried, and the dried extract was used as a control group of the corresponding examples or comparative examples.

[0061] The extracts finally prepared in the examples and comparative examples and the corresponding control group extracts were dissolved in the base wine used in the corresponding examples or comparative examples to keep their concentrations consistent, and the bitterness value of each sample was measured using an electronic tongue. The specific operating steps are as follows: pour the samples into the electronic tongue sample beakers respectively, and then place them on the sampling analysis device. Before measuring the samples, the electronic tongue system needs to complete initialization, self-test, calibration and other links, and rinse with water for 300 seconds after the measurement. The data acquisition time of the sample is 150 seconds. Each sample is tested 4 times, and the last 3 data are taken and the average value is calculated. The bitterness value reduction rate is calculated using the following formula:

[0062] Bitterness value reduction rate = [(CD) / C] × 100%

[0063] Where:

[0064] C is the bitterness value of the Cistanche deserticola control group;

[0065] D is the bitterness value of the Cistanche deserticola extract finally obtained in the corresponding embodiment or comparative example of the control group.

[0066] The calculated bitterness values ​​of the different examples and comparative examples are shown in the following table:

[0067] Group Bitterness value reduction rate / % Example 1 Control Group / Example 1 86.3±0.4 Example 2 Control Group / Example 2 86.4±0.3 Example 3 Control Group / Example 3 86.6±0.5 Comparative Example 1 Control Group / Comparative Example 1 17.9±0.2 Comparative Example 2 Control Group / Comparative Example 2 9.3±0.3 Comparative Example 3 Control Group / Comparative Example 3 86.2±0.5

[0068] As can be seen from the data in the above table, the bitterness value reduction rate of the samples in Examples 1-3 and Comparative Example 3 is significantly different from that in Comparative Example 1-2, and the bitterness value reduction rate is higher than 80%, indicating that the low-metal salt Cistanche deserticola wine extract prepared by the present invention has a significantly reduced bitterness value compared with the conventional preparation process of Cistanche deserticola extract.

[0069] Chromaticity stability comparison:

[0070] In the above examples and comparative examples, the Cistanche deserticola extract obtained after reflux extraction was dried, and the dried extract was used as a control group of the corresponding examples or comparative examples.

[0071] The extracts finally prepared in the Examples and Comparative Examples and the corresponding control group extracts were dissolved in the base wine used in the corresponding Examples or Comparative Examples to keep their concentrations consistent. 1 mL of each was taken, diluted 500-fold, and then the absorbance was measured at a wavelength of 282 nm. Samples were taken at 30 days, 60 days, and 90 days, respectively, to measure their absorbance values.

[0072] The absorbance values ​​of different examples and comparative examples at different time points are shown in the following table:

[0073]

[0074]

[0075] It can be seen from the data in the above table that, as time goes on, the chromaticity values ​​of the embodiments and comparative examples do not change significantly compared with the control group, which indicates that the low-metal salt Cistanche deserticola wine extract prepared by the method of the present invention has good chromaticity stability.

[0076] Based on the above data analysis results, the low-metal salt Cistanche deserticola wine extract prepared in the examples of the present invention has the characteristics of low metal salt content, high bitterness value reduction rate, strong chromaticity stability in wine, and convenient industrial production.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a low-metal salt Cistanche deserticola wine extract, characterized in that: The steps include: Step 1: mixing the Cistanche deserticola with the base wine, heating and refluxing the mixture, and performing solid-liquid separation to obtain an extract; Step 2: vacuum concentrating the extract to obtain a concentrated solution; Step 3: Mix the concentrated solution with sodium bicarbonate and dissolve it under ultrasonic wave, the amount of sodium bicarbonate added is 0.5%-1% of the mass of the Cistanche deserticola concentrated solution, the ultrasonic wave power is 120-180W, and the ultrasonic wave temperature is 40-55°C; Step 4: Mix the concentrated solution containing sodium bicarbonate with dilute hydrochloric acid and stir until there are no bubbles, then add oxalic acid solution and stir. The amount of dilute hydrochloric acid added is 0.5%-1% by volume of the Cistanche deserticola concentrate, and the amount of oxalic acid added is 0.1%-0.5% by mass of the Cistanche deserticola concentrate. After adding oxalic acid, the stirring reaction time is 2-10 hours, and the stirring speed is 50-100 rpm. Step 5: Pass the solution obtained in step 4 through a filter bag to collect the permeate, and then pass it through a ceramic membrane to obtain the ceramic membrane permeate; Step 6: subjecting the ceramic membrane permeate to dynamic high-pressure microfluidization treatment to obtain a Cistanche deserticola effluent; Step 7: Dry the Cistanche deserticola effluent under vacuum at low temperature to obtain a low-metal salt Cistanche deserticola wine extract.

2. The method for preparing the low-metal salt Cistanche deserticola wine extract according to claim 1, wherein: In step 1, the base wine concentration is 40-80% vol, and the multiple of the base wine is 4-6 times.

3. The method for preparing the low-metal salt Cistanche deserticola wine extract according to claim 1, wherein: In step 1, the temperature of the heating reflux extraction is 50-85° C., the extraction time is 1-3 hours, and the reflux extraction method is condensation reflux extraction or dynamic circulation extraction.

4. The method for preparing the low-metal salt Cistanche deserticola wine extract according to claim 1, wherein: In step 2, the concentration temperature is 40-55°C, and the concentration end point is 1 / 3-1 / 4 of the original volume.

5. The method for preparing the low-metal salt Cistanche deserticola wine extract according to claim 1, wherein: In step five, the pore size of the filter bag is 200-300 mesh, and the pore size of the ceramic membrane is 50-150 nm.

6. The method for preparing the low-metal salt Cistanche deserticola wine extract according to claim 1, wherein: In step six, the dynamic high-pressure microfluidization treatment pressure is 60-170 MPa, and the number of cycles is 3-7 times.

7. The method for preparing the low-metal salt Cistanche deserticola wine extract according to claim 1, wherein: In step seven, the drying temperature of the Cistanche deserticola effluent is 40-60°C.

Images