A hydroxytyrosol and a method for separating and purifying the same

Abstract

The application discloses a hydroxytyrosol and a separation and purification method thereof. The method comprises the following steps: concentrating a catalytic liquid containing hydroxytyrosol to obtain a first concentrated liquid; adding a drying aid to the first concentrated liquid, uniformly mixing to obtain a mixed liquid, and performing spray drying to obtain a powder; performing leaching on the powder, collecting a solvent phase as a second concentrated liquid, and sequentially performing thin film evaporation concentration, molecular distillation on the second concentrated liquid to obtain finished hydroxytyrosol. The method not only avoids oxidation and decomposition of the hydroxytyrosol, but also avoids water removal operation of repeatedly using a solvent, and greatly reduces the extraction cost.

Description

Technical Field

[0001] This invention relates to a hydroxytyrosol and its separation and purification method, belonging to the field of biochemical separation and purification technology. Background Technology

[0002] Hydroxytyrosol is a phenolic compound with the chemical name 3,4-dihydroxyphenylethanol and the molecular formula C8H12H2O. 10 O3, with a relative molecular weight of 154.16, exhibits good lipid and water solubility, readily soluble in water and ethyl acetate. Hydroxytyrosol, a bioactive substance extracted from olive oil, possesses high safety and strong antioxidant and mitochondrial-promoting biological activities, showing promising applications in the prevention and treatment of various diseases. In nature, hydroxytyrosol mainly exists in the form of non-free oleuropein in olive fruits and leaves. Industrially, it can be extracted and separated from olive oil production wastewater, olive leaves, and juice. Due to the limitation of plant resources, large-scale industrial production of plant-extracted hydroxytyrosol is difficult to achieve.

[0003] Currently, hydroxytyrosol is mainly obtained by the following methods: (1) Extracting hydroxytyrosol from the pulp, stems or leaves of plants of the genus *Olive* in the family Burseraceae. The advantage of this method is that the source is wide, the raw materials are easy to obtain, and there is less environmental pollution. However, this method requires a large amount of raw materials and is seriously affected by the planting area and growth cycle. The yield of hydroxytyrosol is low and it is difficult to produce industrially. (2) Obtaining hydroxytyrosol by biological fermentation. The bacteria are modified by genetic engineering. The culture cycle is long, the fermentation density is low, the purification process of hydroxytyrosol is easily oxidized, the storage period is short, the purification is difficult, and the industrial scale-up cost is high. (3) Preparing hydroxytyrosol by chemical synthesis. Patent CN106187708A discloses a method for preparing high-purity hydroxytyrosol from olive bitter glycosides in the chemical field. The raw materials containing olive bitter glycosides are hydrolyzed with ethanol as solvent, the hydrolysate is concentrated to a viscous state, and the ethyl acetate is repeatedly extracted. Finally, the organic phase concentrate is reconstituted with ethyl acetate and separated by silica gel column chromatography to obtain hydroxytyrosol. The acid hydrolysis temperature of this method needs to be controlled at 80-1000℃, and repeated separation with silica gel chromatography columns is still required. The process is complicated and requires a large amount of organic reagents. In addition, the hydroxytyrosol content in the raw material is low, making it unsuitable for industrial-scale production.

[0004] Industrially, lithium aluminum hydride is commonly used to reduce methyl 3,4-dihydroxyphenylacetate, using dry tetrahydrofuran as a solvent. The crude product is then subjected to high-temperature vacuum distillation to obtain hydroxytyrosol. This process has the following disadvantages: (1) During the feeding process, the addition of the strong reducing agent lithium aluminum hydride generates a large number of bubbles, leading to a rapid temperature rise; (2) Tetrahydrofuran is used as a solvent, which is highly toxic and causes serious environmental pollution; (3) When the vacuum distillation temperature reaches above 200°C, hydroxytyrosol will be oxidized, generating black-brown tar, which affects the product yield. In addition, high-temperature operation is not suitable for the production of large quantities of high-purity hydroxytyrosol. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for separating and purifying hydroxytyrosol, which effectively avoids the oxidative decomposition of hydroxytyrosol and reduces extraction costs.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The present invention provides a method for purifying hydroxytyrosol, comprising: concentrating a catalytic solution containing hydroxytyrosol to obtain a first concentrate;

[0008] A drying aid is added to the first concentrate while maintaining a constant temperature range. The mixture is then spray-dried to obtain a powder.

[0009] The powder was extracted, and the solvent phase was collected to obtain a second concentrated solution;

[0010] The second concentrate is concentrated by thin-film evaporation to obtain the third concentrate;

[0011] The third concentrate was subjected to molecular distillation to obtain the final product, hydroxytyrosol.

[0012] Furthermore, the catalyst containing hydroxytyrosol is concentrated, including by concentrating the catalyst containing hydroxytyrosol through at least two of the following methods: ceramic membrane, ultrafiltration, nanofiltration, and reverse osmosis membrane.

[0013] Furthermore, the concentration of the first concentrate is 10-50 g / L, and the constant temperature range is 20-50 °C.

[0014] Furthermore, the solid content of the mixture is 5wt%-50wt%.

[0015] Furthermore, the drying agent is at least one of α-cyclodextrin, β-cyclodextrin, sweet potato starch, dextrin, inulin, sodium carboxymethyl cellulose, whey powder, gluten powder, and gum arabic, preferably a mixture of two or more.

[0016] Furthermore, the solvent used for extracting the powder is at least one selected from ethyl acetate, methanol, ethanol, isopropanol, methyl acetate, and dimethyl sulfoxide.

[0017] Furthermore, the spray drying adopts a nozzle-type airflow atomization method, with an inlet air temperature of 130-200℃, an outlet air temperature of 60-120℃, and a feeding speed of 200-1200kg / h.

[0018] Furthermore, the thin-film evaporation concentration includes:

[0019] The second concentrate was subjected to thin-film evaporation under the following conditions: vacuum degree 100-200 Pa, distillation temperature 40-110℃, material flow rate 10-500 kg / h, condensation surface temperature 30-50℃, scraper rotation speed 80-200 r / min, and feed port circulating water temperature 50-80℃.

[0020] Furthermore, the molecular distillation includes:

[0021] The third concentrate was subjected to molecular distillation under the following conditions: vacuum degree 0.05-80 Pa, distillation temperature 70-150℃, material flow rate 5-200 kg / h, condensation surface temperature 25-70℃, scraper rotation speed 100-300 r / min, and feed port circulating water temperature 40-80℃.

[0022] The present invention also provides a hydroxytyrosol, which is prepared according to any of the purification methods described above.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0024] This invention provides a method for purifying hydroxytyrosol by converting hydroxytyrosol from a liquid state to a solid state through extraction and purification. Unlike conventional liquid extraction and separation processes for hydroxytyrosol, the liquid volume is concentrated 10 times to prepare a solid paste. At the same time, the extraction solvent is reduced from 3 times to 2 times. This not only reduces the loss of hydroxytyrosol due to oxidation and decomposition during the process, but also reduces the amount of solvent used by more than 10 times, thus avoiding the generation of a large amount of wastewater.

[0025] This invention employs a solid-state extraction method, allowing for the recycling and reuse of the extracted auxiliary materials, thus avoiding the generation of solid waste and waste liquid. It also significantly reduces production costs, is easy to operate, and operates under mild conditions, making it suitable for large-scale industrial production. Attached Figure Description

[0026] Figure 1 This is the HPLC chromatogram of the hydroxytyrosol reference standard provided by the present invention;

[0027] Figure 2 This is the HPLC chromatogram of hydroxytyrosol obtained by purification in Example 1 of the present invention;

[0028] Figure 3 This is a flowchart of the hydroxytyrosol purification process provided in an embodiment of the present invention. Detailed Implementation

[0029] This invention provides a method for purifying hydroxytyrosol, comprising:

[0030] Step 1: Concentrate the catalyst solution containing hydroxytyrosol through at least two of the following methods: ceramic membrane, ultrafiltration, nanofiltration, and reverse osmosis membrane, to obtain a first concentrate with a concentration of 10-50 g / L.

[0031] Step 2: Add a drying agent to the first concentrate, mix evenly to obtain a mixture with a solid content of 5wt%-50wt%, and spray dry to obtain a powder.

[0032] Step 3: Extract the powder 1-3 times using at least one of ethyl acetate, methanol, ethanol, isopropanol, methyl acetate, and dimethyl sulfoxide, and collect the solvent phase as the second concentrate. Since the second concentrate contains impurities and residual solvents, including two or more of the following impurities: hydroxytyrosol acetate, fatty acids, sodium chloride, ammonium sulfate, magnesium sulfate, glucose, and protein; and the residual solvents are one or more of ethyl acetate, water, acetic acid, and ethanol, further purification is required.

[0033] Step 4: The second concentrate is subjected to thin-film evaporation under the following conditions: circulating water temperature at the feed port of 50-80℃, vacuum degree of 100-200Pa, distillation temperature of 40-110℃, material flow rate of 10-500kg / h, condensation surface temperature of 30-50℃, and scraper rotation speed of 80-200r / min, to obtain the third concentrate.

[0034] Step 5: Molecular distillation is carried out on the third concentrate under the following conditions: circulating water temperature at the feed port is 40-80℃, vacuum degree is 0.05-80Pa, distillation temperature is 70-150℃, material flow rate is 5-200kg / h, condensation surface temperature is 25-70℃, and scraper rotation speed is 100-300r / min to obtain the finished product hydroxytyrosol.

[0035] The drying agent is at least one of α-cyclodextrin, β-cyclodextrin, sweet potato starch, dextrin, inulin, sodium carboxymethyl cellulose, whey powder, gluten powder, and gum arabic, preferably a mixture of two or more.

[0036] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0037] Example 1:

[0038] like Figure 3The diagram shown is a flowchart of the hydroxytyrosol purification process in this embodiment. This embodiment uses a 5m... 3 The catalyst solution containing hydroxytyrosol was separated and concentrated using ceramic membranes, nanofiltration membranes, and reverse osmosis membranes to obtain 1.5m... 3 First concentrated solution of hydroxytyrosol with a concentration of 40 g / L.

[0039] 100 kg of dextrin and 200 kg of β-cyclodextrin were added to the first concentrated hydroxytyrosol solution under magnetic stirring at 25 °C to prepare a mixture with a solid content of 24 wt%. After stirring evenly for 30 min, spray drying was started. The inlet air temperature was set at 150 °C, the feed rate was 300 kg / h, the outlet air temperature was 92 °C, and 232 kg of powder was collected.

[0040] The powder was extracted three times with methanol, and the solvent phase was collected to obtain a second concentrate. The second concentrate was poured into the feed port of a thin-film evaporator, and the material was heated by circulating water at 60°C. After preheating the material for 10 minutes, thin-film evaporation and concentration were carried out under the conditions of vacuum degree 180Pa, distillation temperature 102°C, material flow rate 25kg / h, condensation surface temperature 35°C, and scraper rotation speed 120r / min, finally yielding 61.3kg of a brownish-brown viscous third concentrate.

[0041] 51.3 kg of the third concentrated liquid from the evaporation of a brownish-black viscous film was poured into the feeding port, and the material was heated by circulating water at 65°C. After preheating the material for 10 min, two molecular distillations were performed under the conditions of vacuum degree 1 Pa, distillation temperature 101°C, material flow rate 10 kg / h, condensation surface temperature 40°C, and scraper rotation speed 180 r / min, finally yielding 32.3 kg of molecularly distilled material, which was the finished product hydroxytyrosol, with a purity of 99.7% as determined by HPLC.

[0042] like Figure 1 The figure shown is the HPLC chromatogram of hydroxytyrosol reference standard. Figure 2 The figure shows the HPLC chromatogram of hydroxytyrosol obtained by purification in Example 1 of this invention. As can be seen from the comparison of the figures, the purity of the hydroxytyrosol prepared by this method is achieved, which proves the scale-up feasibility of this invention.

[0043] Example 2:

[0044] 30m 3 The hydroxytyrosol catalyst solution was separated and concentrated using ceramic membranes, nanofiltration membranes, and reverse osmosis membranes to obtain 24m. 3 Hydroxytyrosol first concentrate with a concentration of 35 g / L.

[0045] 2100 kg of additive powder was added to the first concentrated hydroxytyrosol solution under mechanical stirring at 35°C to prepare a mixture with a solid content of 12.25 wt%. After stirring for 60 min until homogeneous, spray drying was started. The spray drying settings were: inlet air temperature 178°C, feed rate 450 kg / h, outlet air temperature 105°C, and 2540 kg of powder collected.

[0046] The collected powder was extracted twice with ethanol, and the solvent phase was collected to obtain a second concentrate. The second concentrate was poured into the feed port of a thin-film evaporator, and the material was heated by circulating water at 75°C. After preheating the material for 10 minutes, thin-film evaporation and concentration were carried out under the conditions of vacuum degree 120Pa, distillation temperature 85°C, material flow rate 200kg / h, condensation temperature 45°C, and scraper rotation speed 90r / min. Finally, 749kg of the third concentrate from the thin-film evaporation was obtained, which was a brownish-black viscous liquid.

[0047] 749 kg of the brownish-black viscous film-thickened concentrate was poured into the feeding port, and the material was heated by circulating water at 75°C. After preheating for 10 min, two molecular distillations were performed under the following conditions: vacuum degree 25 Pa, distillation temperature 115°C, material flow rate 100 kg / h, condensation surface temperature 30°C, and scraper rotation speed 280 r / min. The final product, 438 kg of molecularly distilled material, was hydroxytyrosol, with a purity of 99.3% as determined by HPLC.

[0048] Example 3:

[0049] 50m 3 The hydroxytyrosol catalyst solution was separated and concentrated using ceramic membranes, nanofiltration membranes, and reverse osmosis membranes to obtain 30m. 3 First concentrated solution of hydroxytyrosol with a concentration of 38 g / L.

[0050] 9408 kg of inulin and 2352 kg of whey powder were added to the first concentrated hydroxytyrosol solution under mechanical stirring at 40℃ to prepare a mixture with a solid content of 43 wt%. The mixture was stirred for 30 minutes until it was uniform, and then spray drying was started. The inlet air temperature was set at 198℃, the feed rate was 850 kg / h, the outlet air temperature was 88℃, and 3150 kg of powder was collected.

[0051] The powder was extracted twice with ethyl acetate, and the solvent phase was collected to obtain a second concentrate. The second concentrate was poured into the feed port of a thin-film evaporator, and the material was heated by circulating water at 55°C. After preheating the material for 20 minutes, thin-film evaporation and concentration were carried out under the conditions of vacuum degree 100Pa, distillation temperature 75°C, material flow rate 450kg / h, condensation temperature 40°C, and scraper rotation speed 160r / min, finally yielding 800kg of a brownish-brown viscous third concentrate.

[0052] 800 kg of the third concentrated liquid from the evaporation of a brownish-black viscous film was poured into the feeding port, and the material was heated by circulating water at 55°C. After preheating the material for 20 min, three molecular distillations were performed under the following conditions: vacuum degree 63 Pa, distillation temperature 145°C, material flow rate 160 kg / h, condensation surface temperature 50°C, and scraper rotation speed 220 r / min. Finally, 522 kg of molecularly distilled material was obtained, which was the finished product hydroxytyrosol, with a purity of 99.6% as determined by HPLC.

[0053] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for purifying hydroxytyrosol, characterized in that, include: The catalyst solution containing hydroxytyrosol was concentrated to obtain the first concentrate. A drying aid is added to the first concentrate while maintaining a constant temperature range, and the mixture is stirred evenly to form a mixture. This mixture is then spray-dried to obtain a powder. The concentration of the first concentrate is 10-50 g / L, and the constant temperature range is 20-50℃. The drying aid is at least one of α-cyclodextrin, β-cyclodextrin, sweet potato starch, dextrin, inulin, sodium carboxymethyl cellulose, whey powder, gluten powder, and gum arabic. The spray drying employs a nozzle-type airflow atomization method, with an inlet air temperature of 130-200℃, an outlet air temperature of 60-120℃, and a feed rate of 200-1200 kg / h. The powder was extracted, and the solvent phase was collected to obtain a second concentrated solution; The second concentrate is concentrated by thin-film evaporation to obtain a third concentrate; the thin-film evaporation concentration includes: The second concentrate was subjected to thin-film evaporation under the following conditions: vacuum degree 100-200Pa, distillation temperature 40-110℃, material flow rate 10-500kg / h, condensation surface temperature 30-50℃, scraper rotation speed 80-200r / min, and feed port circulating water temperature 50-80℃. The third concentrate is subjected to molecular distillation to obtain the final product, hydroxytyrosol; the molecular distillation includes: The third concentrate was subjected to molecular distillation under the following conditions: vacuum degree 0.05-80 Pa, distillation temperature 70-150℃, material flow rate 5-200 kg / h, condensation surface temperature 25-70℃, scraper rotation speed 100-300 r / min, and feed port circulating water temperature 40-80℃.

2. The purification method according to claim 1, characterized in that, Concentrating a catalyst containing hydroxytyrosol includes concentrating the catalyst containing hydroxytyrosol through at least two of the following methods: ceramic membrane, ultrafiltration, nanofiltration, and reverse osmosis membrane.

3. The purification method according to claim 1, characterized in that, The solid content of the mixture is 5wt%-50wt%.

4. The purification method according to claim 1, characterized in that, The solvent used for extracting the powder is at least one of ethyl acetate, methanol, ethanol, isopropanol, methyl acetate, and dimethyl sulfoxide.

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