Phytosterol ester as well as preparation method and application thereof

Abstract

The invention relates to a phytosterol ester as well as a preparation method and application thereof, the preparation method comprises the following steps: sequentially carrying out saponification reaction and solid-liquid separation on a vegetable oil deodorized distillate to obtain a saponified solution; extracting the saponified solution to obtain an organic phase, and sequentially carrying out evaporation concentration and solid-liquid separation on the organic phase to obtain an extracted concentrated solution; sequentially performing dissolution, decoloration and solid-liquid separation on the extraction concentrated solution to obtain filtrate; sequentially carrying out cooling crystallization, solid-liquid separation and drying on the filtrate to obtain purified phytosterol; carrying out esterification reaction on phytosterol to obtain a reaction product; and sequentially carrying out first purification treatment, second purification treatment and third purification treatment on the reaction product to obtain a phytosterol ester product. According to the preparation method provided by the invention, the problems of poor solubility, low transdermal absorption rate, insufficient stability and the like of the phytosterol are solved, and the yield and the purity of the phytosterol ester are improved, so that the phytosterol ester has a wide application prospect in the field of skin care products.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of phytosterol ester preparation, and particularly relates to a phytosterol ester and a preparation method and application thereof. BACKGROUND

[0002] Phytosterol ester is a natural plant-derived lipid derivative formed by esterification of phytosterol and fatty acid, and is one of the most important skin barrier repair components. Phytosterol widely exists in plant oils such as soybean and corn, and was found to have the function of regulating cholesterol in the 1950s. In the early 21st century, the esterification product was confirmed to be able to significantly improve the bioavailability. Phytosterol ester mainly has the physiological functions of enhancing skin barrier and soothing and repairing. In recent years, it has been found that phytosterol ester with a specific structure (such as phytosterol isostearate) has a regulating effect on skin microecological balance.

[0003] Phytosterol isostearate is a derivative prepared by esterification of phytosterol and isostearic acid, and is widely favored in high-end skin care products, and is often used as a core component of barrier repair, and has excellent soothing anti-sensitivity, keratin layer strengthening and other functions. At present, phytosterol ester is applied in the fields of medicine, functional food and efficacy skin care. However, due to the difference of esterification process, the existing process has problems such as unstable product purity, limited biological activity, and uneven production cost and efficacy performance.

[0004] In order to optimize the functional characteristics of phytosterol ester, the mainstream preparation technologies include: enzyme catalysis method, under the catalysis of lipase, phytosterol and isostearic acid are directionally esterified under mild conditions, but there are problems such as high enzyme cost and slow reaction rate; chemical synthesis method, using p-toluenesulfonic acid as catalyst, high-purity product is obtained by molecular distillation purification; supercritical fluid technology, solvent-free esterification is realized in supercritical CO2 medium, which avoids isomerization caused by high temperature, but the equipment requirement is high and the operation is complex.

[0005] There are still deficiencies in the existing preparation methods in terms of conversion rate, color control, environmental protection and product stability of phytosterol ester. Therefore, how to realize high conversion rate, high purity and high stability of phytosterol ester, while controlling the production process to be green and environmentally friendly and reducing waste emission, is a technical problem to be solved at present. SUMMARY

[0006] In view of the above problems, the present application aims to provide a phytosterol ester and a preparation method and application thereof, compared with the prior art, the preparation method provided by the present application is green and efficient, significantly reduces the production cost, makes the conversion rate of phytosterol ester reach a higher level, the molecular structure is more stable, the product quality is more uniform, and the physiological activity of phytosterol ester is fully released. The obtained phytosterol ester product can effectively repair the skin barrier function and inhibit free radical damage, thereby helping to enhance the skin resistance, relieve sensitive symptoms, improve the water locking ability of the stratum corneum, solve the problem of damaged skin barrier, and long-term maintain the moisturizing state of the skin. Phytosterol has the effects of regulating sebum secretion, enhancing skin elasticity, and soothing irritation, and through esterification modification, the combination of phytosterol and isostearic acid significantly improves the biocompatibility of phytosterol ester and greatly optimizes the transdermal absorption efficiency, which has key application value in skin care products such as repair cream, soothing serum, and barrier milk, and has become one of the irreplaceable core active ingredients in high-end functional skin care products.

[0007] To achieve the object of the present application, the following technical solutions are adopted:

[0008] In a first aspect, the present application provides a preparation method of phytosterol ester, which comprises the following steps:

[0009] (1) subjecting a plant oil deodorization distillate to a saponification reaction and a solid-liquid separation in sequence to obtain a saponification liquid;

[0010] (2) subjecting the saponification liquid obtained in step (1) to extraction to obtain an organic phase, and subjecting the organic phase to evaporation concentration and solid-liquid separation in sequence to obtain an extraction concentrated liquid;

[0011] (3) subjecting the extraction concentrated liquid obtained in step (2) to dissolution, decolorization and solid-liquid separation in sequence to obtain a filtrate; and subjecting the filtrate to cooling crystallization, solid-liquid separation and drying in sequence to obtain a purified phytosterol;

[0012] (4) subjecting the phytosterol obtained in step (3) to an esterification reaction to obtain a reaction product;

[0013] (5) subjecting the reaction product obtained in step (4) to first purification treatment, second purification treatment and third purification treatment in sequence to obtain a phytosterol ester product.

[0014] In the present application, the saponification liquid can be effectively extracted from the plant oil deodorization distillate by saponification and solid-liquid separation; the phytosterol can be efficiently extracted and concentrated by extraction, evaporation and concentration, and solid-liquid separation; the impurities and pigments can be removed by dissolving, decolorizing and solid-liquid separation of the extracted and concentrated liquid; and the high-purity phytosterol can be finally obtained by cooling crystallization, solid-liquid separation and drying. The purity of the phytosterol is improved by the foregoing process, which lays a foundation for the production of high-quality phytosterol ester. The phytosterol ester is prepared by esterification reaction, and the reaction product is subjected to first, second and third purification treatments to gradually remove impurities and by-products in the reaction product, so that the high-purity phytosterol ester product is finally obtained.

[0015] In the present application, the plant oil deodorization distillate is not particularly limited and can be any plant oil deodorization distillate used in the preparation of phytosterol in the art, for example, can be soybean oil deodorization distillate.

[0016] Preferably, the temperature of the saponification reaction in step (1) is 80-85℃, for example, can be 80℃, 81℃, 82℃, 83℃, 84℃ or 85℃, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0017] Preferably, the time of the saponification reaction is 1.5-2h, for example, can be 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2h, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0018] In the present application, the saponification reaction generally includes two stages. In the first stage, i.e. the preheating stage, the plant oil deodorization distillate is preheated to 60-65℃, and the reaction is initiated by adding alkali (for example, sodium hydroxide) with a mass concentration of 8-12% and reacting for 0.4-0.8h. In the second stage, i.e. the reaction stage, the temperature is gradually increased to 80-85℃ at a rate of 0.8-2.5℃ / min, additional alkali with a mass concentration of 8-12% is added, and the reaction is continued for 1.5-2h. The saponification reaction is carried out with stirring at a stirring rate of 60-100rpm, which can reduce the degradation of sterols caused by local over-alkalization and reduce the generation of by-products. After the saponification reaction is completed, the material is generally sent to a settling tank, where it will be stratified by standing. The solid-liquid separation is performed on all the materials in the settling tank, and the unsaponified oil and solid impurities are removed by using a hot filter press (operating at 75-85℃). The hot filter residue is subjected to supercritical CO2 extraction to recover residual sterols (which can increase the sterol yield by more than 13.8%, and under optimal conditions, the sterol yield can be increased by 15%), and the residue is used as a raw material for biodiesel.

[0019] Preferably, the temperature of the extraction in step (2) is 25-30℃, for example, it can be 25℃, 26℃, 27℃, 28℃, 29℃ or 30℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0020] Preferably, the time of the extraction is 1-2h, for example, it can be 1h, 1.2h, 1.4h, 1.6h, 1.8h or 2h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0021] Preferably, the extraction agent used in the extraction includes 2-methyltetrahydrofuran.

[0022] Preferably, the mass ratio of the saponification solution to the extraction agent in the extraction is 1:(4-5), for example, it can be 1:4, 1:4.2, 1:4.4, 1:4.6, 1:4.8 or 1:5, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0023] In the present application, stirring is generally also carried out during the extraction, the stirring rate is 50-80rpm, and the stirring time is 0.5-3h. Through the extraction, the non-saponification substances (sterol, vitamin E, etc.) can be promoted to dissolve out. After the extraction, the layers are separated by standing, the lower layer of the aqueous phase (containing glycerol and salt) is discharged to the wastewater treatment system, and the upper layer of the organic phase (containing sterol) is transferred to a solvent recovery tower for evaporation and concentration, for example, a multiple-effect evaporator is used for concentration, so as to recover the extraction agent. The extracted concentrated solution obtained after concentration is detected for the purity of plant sterol by HPLC, and solid-liquid separation is carried out, for example, a plate and frame filter press (using a polypropylene filter core with a filtering precision of 0.5μm) is used to remove the insoluble substances.

[0024] Preferably, alcohol is added in the dissolving in step (3).

[0025] Preferably, the alcohol includes methanol.

[0026] Preferably, the mass ratio of the extracted concentrated solution to methanol is 1:(6-8), for example, it can be 1:6, 1:6.2, 1:6.5, 1:6.8, 1:7, 1:7.5 or 1:8, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0027] Preferably, the temperature of the dissolving is 60-70℃, for example, it can be 60℃, 61℃, 62℃, 63℃, 64℃, 65℃, 66℃, 68℃ or 70℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0028] Preferably, the decolorization includes: mixing the dissolved liquid with activated carbon.

[0029] Preferably, the mass of the activated carbon is 1.5-2.5% of the mass of the dissolved feed liquid, for example, it can be 1.5%, 1.6%, 1.8%, 2%, 2.2% or 2.5%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0030] Preferably, the decolorization time is 20-30 min, for example, it can be 20 min, 22 min, 24 min, 26 min, 28 min or 30 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0031] In the present application, mixing the extraction concentrate and methanol can promote the dissolution of phytosterols, and effective decolorization can be achieved by adding activated carbon, followed by solid-liquid separation, for example, using a plate and frame filter press (0.5 μm filter) to remove impurities.

[0032] Preferably, the cooling rate of the cooling crystallization is 0.5-1.5°C / min, for example, it can be 0.5°C / min, 0.6°C / min, 0.8°C / min, 1°C / min, 1.2°C / min or 1.5°C / min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0033] Preferably, the cooling endpoint of the cooling crystallization is -15 to -20°C, for example, it can be -15°C, -16°C, -17°C, -18°C, -19°C or -20°C, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0034] Preferably, the crystallization time at the cooling endpoint is 12-16 h, for example, it can be 12 h, 13 h, 14 h, 15 h or 16 h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0035] Preferably, ultrasound and / or pulsed microwave radiation is applied during the cooling crystallization.

[0036] Preferably, the frequency of the ultrasound is 35-45 kHz, for example, it can be 35 kHz, 36 kHz, 38 kHz, 40 kHz, 44 kHz or 45 kHz, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0037] Preferably, the power of the ultrasound is 150-250 W, for example, it can be 150 W, 160 W, 180 W, 200 W, 220 W, 240 W or 250 W, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0038] Preferably, the power of the pulsed microwave radiation is 550-650 W, for example, it can be 550 W, 560 W, 580 W, 600 W, 620 W, 640 W or 650 W, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0039] In the present application, the pulse period of the pulsed microwave radiation is 8-15 s, wherein the microwave radiation time accounts for 40-60% of the period, and 5 s on / 5 s off is selected for a 10 s period.

[0040] In the present application, the filtrate is transferred to an ultrasonic-microwave coupled crystallization system, and ultrasonic waves and pulsed microwave radiation are applied simultaneously during the process of cooling crystallization, which can promote crystal nucleation and growth regulation, and finally the crystal particle size D 90 The control is 15±2 μm, and the crystal grows sufficiently, and the purity of phytosterol obtained by HPLC detection is high. Then, solid-liquid separation is performed, for example, a horizontal siphon centrifuge (rotating speed of 1500-4500 rpm) is used to separate the crystal, the obtained wet crystal is dried in a fluidized bed (hot air at 35-45°C) to remove residual solvent, and the process is repeated 1-2 times, and finally high-purity phytosterol crystal is obtained.

[0041] Preferably, the raw material used in the esterification reaction of step (4) further comprises isostearic acid and a catalyst.

[0042] Preferably, the catalyst comprises p-toluenesulfonic acid.

[0043] Preferably, the isostearic acid is subjected to microwave activation before the esterification reaction.

[0044] Preferably, the power of the microwave activation is 500-700 W, for example, it can be 500 W, 520 W, 540 W, 560 W, 580 W, 600 W, 620 W, 640 W, 660 W, 680 W or 700 W, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0045] Preferably, the frequency of the microwave activation is 2400-2500 MHz, for example, it can be 2400 MHz, 2410 MHz, 2420 MHz, 2440 MHz, 2460 MHz, 2480 MHz or 2500 MHz, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0046] Preferably, the time of the microwave activation is 10-20 min, for example, it can be 10 min, 12 min, 14 min, 16 min, 18 min or 20 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0047] In the present application, the isostearic acid is generally subjected to vacuum dehydration, decolorization and other steps before microwave activation. The vacuum dehydration is to pump the crude isostearic acid into a vacuum dehydration kettle, and the crude isostearic acid is subjected to vacuum dehydration at 105-135℃ and -0.085 to -0.100 MPa for 0.5-4h, and the moisture content is monitored by an online moisture meter to ensure that the moisture content is less than or equal to 0.05%, so as to ensure the subsequent reaction efficiency. The decolorization is to add 2-4% of food-grade activated clay based on the mass of the isostearic acid, and the mixture is stirred at 70-90℃ for 20-45min, and then the mixture is subjected to solid-liquid separation, for example, the activated clay and impurities are removed by using a plate and frame filter press (0.2μm filter core), so as to ensure that the Gardner color is less than or equal to 2 (determined by a colorimeter).

[0048] In the present application, the isostearic acid is subjected to solid-liquid separation after microwave activation, for example, the isostearic acid is filtered by using a candle filter (0.2μm PTFE membrane), and the temperature is controlled at 76-80℃ to prevent the crystallization of the fatty acid.

[0049] Preferably, the phytosterol is mixed with a solvent before the esterification reaction.

[0050] Preferably, the solvent comprises silicone oil.

[0051] In the present application, the mass ratio of the phytosterol to the solvent is generally 1:(2-5), and the phytosterol is mixed with the silicone oil, and the mixture is stirred at 85-95℃ for 20-60min to form a homogeneous transparent solution.

[0052] Preferably, the molar ratio of the isostearic acid to the phytosterol is 1:(1-2), for example, it can be 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8 or 1:2, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0053] Preferably, the catalyst is added in an amount of 1.5-2% based on the total mass of the reaction system, for example, it can be 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0054] In the present application, the total mass of the reaction system refers to the sum of the masses of the phytosterol, the isostearic acid and the solvent.

[0055] Preferably, the temperature of the esterification reaction is 110-120℃, for example, it can be 110℃, 112℃, 114℃, 116℃, 118℃ or 120℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0056] Preferably, the esterification reaction time is 1.5-2h, for example, it can be 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2h, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0057] In the present application, the esterification reaction is stirred at a rate of 150-200rpm.

[0058] Preferably, the esterification reaction is carried out under nitrogen protection.

[0059] In the present application, the content of nitrogen in the reaction system is <100ppm.

[0060] Preferably, the first purification treatment in step (5) includes: removing the catalyst by first neutralization of the reaction product to obtain a neutralized reaction product, then performing three-stage countercurrent water washing of the neutralized reaction product to obtain a water-washed reaction product, then recovering silicone oil by molecular distillation of the water-washed reaction product to obtain a solvent-removed reaction product, and finally performing flash evaporation under reduced pressure on the solvent-removed reaction product to obtain the esterification product.

[0061] Preferably, the neutralizing agent used in the first neutralization includes a sodium carbonate solution.

[0062] Preferably, the temperature of the first neutralization is 60-70℃, for example, it can be 60℃, 62℃, 64℃, 66℃, 68℃, 69℃ or 70℃, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0063] In the present application, the sodium carbonate solution is used for neutralization in the first neutralization to remove the catalyst, and the mass concentration of the sodium carbonate solution is generally 1-2% and the temperature is 60-70℃.

[0064] Preferably, the water washing temperature of the three-stage countercurrent water washing in the first purification treatment is 60-70℃, for example, it can be 60℃, 62℃, 64℃, 66℃, 68℃, 69℃ or 70℃, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0065] Preferably, the content of sulfonate after the three-stage countercurrent water washing in the first purification treatment is <10ppm, for example, it can be 9ppm, 8ppm, 7ppm, 6ppm, 5ppm, 4ppm, 3ppm or 2ppm, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0066] Preferably, the pH value of the esterification product after the third reverse flow water washing in the first purification process is 7-8, for example, it can be 7, 7.2, 7.4, 7.6, 7.8 or 8, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0067] In the present application, the neutralized reaction product is subjected to the third reverse flow water washing, thereby ensuring that the sulfonate residue is <10 ppm.

[0068] Preferably, the temperature of the molecular distillation in the first purification process is 175-185℃, for example, it can be 175℃, 176℃, 178℃, 180℃, 182℃, 184℃ or 185℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0069] Preferably, the pressure of the molecular distillation in the first purification process is 3-5 Pa, for example, it can be 3 Pa, 3.2 Pa, 3.4 Pa, 3.6 Pa, 3.8 Pa, 4 Pa, 4.2 Pa, 4.4 Pa, 4.6 Pa, 4.8 Pa or 5 Pa, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0070] Preferably, the temperature of the vacuum flash distillation is 70-80℃, for example, it can be 70℃, 71℃, 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, 79℃ or 80℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0071] Preferably, the pressure of the vacuum flash distillation is 2-4 kPa, for example, it can be 2 kPa, 2.2 kPa, 2.4 kPa, 2.6 kPa, 2.8 kPa, 3 kPa, 3.2 kPa, 3.4 kPa, 3.6 kPa, 3.8 kPa or 4 kPa, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0072] In the present application, the silicone oil is recovered by molecular distillation, and the recovered silicone oil is recycled after molecular sieve dehydration. The esterification product obtained after the vacuum flash distillation is light yellow.

[0073] Preferably, the second purification process in step (5) comprises: removing the residual free acid by second neutralization of the esterification product, and then performing the third reverse flow water washing to obtain a washed esterification product; centrifuging the washed esterification product to separate an organic phase containing the esterification product and an aqueous phase, and then dehydrating and drying the organic phase to obtain a phytosteryl ester crude product.

[0074] Preferably, the neutralizing agent used in the second neutralization comprises a sodium bicarbonate solution.

[0075] In the present application, the mass concentration of the sodium bicarbonate solution is generally 4-6%, and the temperature is 65-75℃.

[0076] Preferably, the temperature of the second neutralization is 65-75℃, for example, it can be 65℃, 66℃, 68℃, 70℃, 72℃, 74℃ or 75℃, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0077] Preferably, the end point pH value of the second neutralization is 6.8-7.2, for example, it can be 6.8, 6.9, 7.0, 7.1 or 7.2, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0078] Preferably, the time of the second neutralization is 23-30min, for example, it can be 23min, 24min, 25min, 26min, 28min or 30min, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0079] Preferably, the water washing temperature of the third-stage countercurrent water washing in the second purification treatment is 70-85℃, for example, it can be 70℃, 72℃, 75℃, 76℃, 78℃, 80℃, 82℃, 84℃ or 85℃, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0080] Preferably, the mass percentage of water in the organic phase after the dehydration and drying is ≤0.05%, for example, it can be 0.05%, 0.04%, 0.03%, 0.02% or 0.01%, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0081] In the present application, the residual free acid is completely neutralized by the second neutralization, and the material after the neutralization is subjected to the third-stage countercurrent water washing, each stage stays for 15min, and the water-soluble impurities (such as salt, residual ionic liquid) are fully separated, and the water phase is detected in real time by a conductivity meter until the requirement is reached, otherwise the washing is continued. The washed esterification product enters a centrifugal device such as a disc centrifuge, and is subjected to centrifugation under the condition of a rotation speed of 2000-4000rpm to separate the organic phase (ester product) from the water phase (containing NaHCO3 waste water), and the organic phase is subjected to deep dehydration and drying by a molecular sieve dehydration tower to ensure that the water content is ≤0.05%.

[0082] Preferably, the third purification treatment in step (5) comprises three-stage molecular distillation, that is, the crude phytosteryl ester is subjected to first-stage molecular distillation to obtain a first-stage heavy phase, the obtained first-stage heavy phase is subjected to second-stage molecular distillation to obtain phytosteryl ester product and a second-stage heavy phase; and the obtained second-stage heavy phase is subjected to third-stage distillation to crack and remove heavy components.

[0083] Preferably, the temperature of the first molecular distillation is 175-185°C, for example, it can be 175°C, 176°C, 178°C, 180°C, 182°C, 184°C or 185°C, but is not limited to the listed values, and other values not listed in the range of values are also applicable.

[0084] Preferably, the pressure of the first molecular distillation is 8-10 Pa, for example, it can be 8 Pa, 8.5 Pa, 9 Pa, 9.5 Pa or 10 Pa, but is not limited to the listed values, and other values not listed in the range of values are also applicable.

[0085] Preferably, the temperature of the second molecular distillation is 195-205°C, for example, it can be 195°C, 196°C, 198°C, 200°C, 202°C, 204°C or 205°C, but is not limited to the listed values, and other values not listed in the range of values are also applicable.

[0086] Preferably, the pressure of the second molecular distillation is 0.3-0.7 Pa, for example, it can be 0.3 Pa, 0.35 Pa, 0.4 Pa, 0.45 Pa, 0.5 Pa, 0.55 Pa, 0.6 Pa, 0.65 Pa or 0.7 Pa, but is not limited to the listed values, and other values not listed in the range of values are also applicable.

[0087] Preferably, the temperature of the third molecular distillation is 215-225°C, for example, it can be 215°C, 217°C, 218°C, 220°C, 222°C, 224°C or 225°C, but is not limited to the listed values, and other values not listed in the range of values are also applicable.

[0088] Preferably, the pressure of the third molecular distillation is 0.05-0.15 Pa, for example, it can be 0.05 Pa, 0.06 Pa, 0.08 Pa, 0.10 Pa, 0.12 Pa, 0.14 Pa or 0.15 Pa, but is not limited to the listed values, and other values not listed in the range of values are also applicable.

[0089] In the present application, light components are removed by the first molecular distillation, such as free fatty acids and low-boiling substances (condenser temperature of 60°C), the light components are recovered by a cold trap, and the loss of main products is reduced; the second molecular distillation is used for main product collection, and the automatic membrane scraping system is used for continuous collection; the third molecular distillation is used for removing heavy components, that is, the residues of the second molecular distillation are transferred into a high-temperature distillation unit, cracking and removing high-molecular polymers and pigments (residue ≤3%), and the waste gas is treated by activated carbon adsorption.

[0090] Preferably, the third purification process further comprises a tertiary filtration, i.e., the phytosteryl ester product obtained from the secondary molecular distillation is sequentially subjected to a primary filtration, a secondary filtration and a tertiary filtration.

[0091] Preferably, the primary filtration adopts a multi-bag parallel automatic backflush filter.

[0092] Preferably, the primary filtration has a precision of 3-5 μm, for example, can be 3 μm, 3.5 μm, 4 μm, 4.5 μm or 5 μm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0093] Preferably, the primary filtration has a temperature of 53-57 ℃, for example, can be 53 ℃, 54 ℃, 55 ℃, 56 ℃ or 57 ℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0094] Preferably, the primary filtration has a pressure of 0.2-0.4 MPa, for example, can be 0.2 MPa, 0.22 MPa, 0.24 MPa, 0.26 MPa, 0.28 MPa, 0.3 MPa, 0.32 MPa, 0.34 MPa, 0.36 MPa, 0.38 MPa or 0.4 MPa, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0095] Preferably, the secondary filtration has a precision of 0.08-0.12 μm, for example, can be 0.08 μm, 0.09 μm, 0.10 μm, 0.11 μm or 0.12 μm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0096] Preferably, the secondary filtration adopts an α-alumina ceramic membrane cross-flow system.

[0097] Preferably, the α-alumina ceramic membrane cross-flow system has a transmembrane pressure difference of 0.4-0.6 MPa, for example, can be 0.4 MPa, 0.42 MPa, 0.44 MPa, 0.46 MPa, 0.48 MPa, 0.5 MPa, 0.52 MPa, 0.54 MPa, 0.56 MPa, 0.58 MPa or 0.6 MPa, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0098] Preferably, the α-alumina ceramic membrane cross-flow system has a cross-flow speed of 3.3-3.7 m / s, for example, can be 3.3 m / s, 3.4 m / s, 3.5 m / s, 3.6 m / s or 3.7 m / s, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0099] Preferably, the precision of the third-stage filtration is 0.2-0.25 μm, for example, it can be 0.2 μm, 0.21 μm, 0.22 μm, 0.23 μm, 0.24 μm or 0.25 μm, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0100] Preferably, the third-stage filtration employs a capsule filter.

[0101] Preferably, online steam sterilization is performed in the third-stage filtration.

[0102] In the present application, by first-stage filtration and using a multi-bag parallel automatic backflush filter, a polypropylene melt-blown filter bag and a 304 stainless steel support net are arranged in the multi-bag parallel automatic backflush filter, and the filter bag is operated at a flow rate of 3 m 3 / (m 2 ·h) at 53-57℃ and 0.2-0.4 MPa pressure; the second-stage filtration employs an α-alumina ceramic membrane cross-flow system (filtration precision 0.08-0.12 μm, 19-channel design, 10 m 2 effective area), the transmembrane pressure difference is controlled to be 0.4-0.6 MPa, and the cross-flow speed is 3.3-3.7 m / s; the third-stage filtration employs a 0.2-0.25 μm capsule filter, and online steam sterilization is performed, with a steam temperature of 121℃ and a steam time of 30 min.

[0103] In a second aspect, the present application provides a phytosteryl ester obtained by the preparation method of the phytosteryl ester according to the first aspect of the present application.

[0104] The phytosteryl ester is a natural plant-derived lipid component, and as an active substance for external use, has excellent barrier repair, soothing anti-sensitivity and moisturizing and water-locking effects. Its action mechanism includes: repairing damaged barrier structure by supplementing the skin stratum corneum lipid, reducing transdermal water loss; regulating the skin immune response, inhibiting the release of inflammatory factors, and relieving sensitive symptoms such as redness and stinging; promoting keratinocyte differentiation, enhancing the skin's own moisturizing ability, and maintaining a healthy and moist state; improving microcirculation, and enhancing the skin's defense ability against external stimuli.

[0105] The phytosteryl ester provided by the present application has a high yield, and the molecular structure is optimized, can be more easily absorbed by the skin, has good stability, and at the same time retains its safe and mild properties.

[0106] In a third aspect, the present application provides a use of the phytosteryl ester according to the second aspect of the present application, and the phytosteryl ester is used in skin care products.

[0107] The phytosterol ester provided by the present application has excellent barrier repair, soothing and stabilizing, and long-acting moisturizing effects, and thus becomes an indispensable core active ingredient in high-end skin care products such as repair cream, sensitive skin care product, and moisturizing essence.

[0108] Compared with the prior art, the present application has the following beneficial effects:

[0109] (1) The preparation method provided by the present application improves the yield of phytosterol ester and optimizes the molecular structure through multistage purification treatment, molecular distillation, and multistage filtration, so that the phytosterol ester is more easily absorbed by the skin.

[0110] (2) The preparation method provided by the present application solves the problems of poor solubility, low transdermal absorption rate, and insufficient stability of phytosterol, while retaining the safe and mild characteristics thereof. The excellent barrier repair, soothing and stabilizing, and long-acting moisturizing effects of the phytosterol ester make it an indispensable core active ingredient in high-end skin care products such as repair cream, sensitive skin care product, and moisturizing essence.

[0111] (3) The preparation method provided by the present application can make the purity of phytosterol reach more than 98.8% under relatively optimal conditions, and reach 99.2% under more optimal conditions. The purified phytosterol crystal is subjected to esterification reaction with isostearic acid, and the conversion rate reaches more than 98.2% under relatively optimal conditions, and reaches 98.8% under more optimal conditions. The reaction product is subjected to first purification treatment, second purification treatment, and third purification treatment, and the purity of the obtained phytosterol ester product reaches more than 98.1% under relatively optimal conditions, and reaches 98.5% under more optimal conditions.

[0112] (4) In the preparation method provided by the present application, the extractant and silicone oil can be recycled, and the recovery rate of the extractant reaches more than 89%, and the recovery rate of the silicone oil reaches more than 89%. Under relatively optimal conditions, the recovery rate of the silicone oil reaches 95%, and near-zero waste discharge can be achieved. DETAILED DESCRIPTION

[0113] The technical solutions of the present application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitations on the present application.

[0114] Example 1

[0115] The present embodiment provides a preparation method of phytosterol ester, which comprises the following steps:

[0116] (1) The soybean oil deodorizing distillate is put into a stainless steel reaction kettle, preheated to 60°C, 10% NaOH solution is added and reacted for 0.5h, then the temperature is raised to 80°C at a rate of 1°C / min, 10% NaOH solution is added and reacted for 2h, the saponification reaction is carried out under stirring at a stirring rate of 80rpm, the byproduct generation is reduced, after the saponification reaction, the saponification liquid is pumped into a settling tank through the bottom discharge valve, and the layers are separated by standing, a hot filter press (operating at 80°C) is used to remove unsaponifiable oil and solid impurities, and hot filter residue and saponification liquid are obtained, the residual sterol is recovered by supercritical CO2 extraction, the sterol yield is increased by 15%, and the residue is used for biodiesel raw material;

[0117] (2) The saponification liquid obtained in step (1) is pumped into an extraction kettle for extraction, the extraction temperature is 25°C, the mass ratio of saponification liquid to extraction agent 2-methyltetrahydrofuran is 1:4, stirring is carried out at a speed of 60rpm for 1h to promote the dissolution of non-saponified substances (sterol, vitamin E, etc.), after extraction, the layers are separated by standing, the lower water phase (containing glycerol, salt) is discharged to the wastewater treatment system, and the upper organic phase (containing sterol) is transferred to a multi-effect evaporator for evaporation and concentration, the recovery rate of the extraction agent is 92%, the sterol initial purity is detected by HPLC, and the insoluble substances are removed by using a plate and frame filter press (using a polypropylene filter core with a filtering precision of 0.5μm) to obtain an extraction concentrate;

[0118] (3) The extraction concentrate obtained in step (2) is put into a stainless steel crystallization kettle, industrial methanol is added, the mass ratio of extraction concentrate to methanol is 1:6, and the solution is dissolved at 60°C to obtain a dissolved liquid, then activated carbon is added for decolorization for 30min, the mass of activated carbon accounts for 1.5% of the mass of the dissolved liquid, then impurities are removed by using a plate and frame filter press (0.5μm filter core) to obtain a filtrate; the obtained filtrate is transferred to an ultrasonic-microwave coupled crystallization system, cooled to-20°C at a rate of 1°C / min for 14h, while 40kHz, 200W ultrasonic waves and 600W, 5s on / 5s off pulsed microwave radiation are applied to promote the homogeneous nucleation and growth of crystals, and finally the crystal size D 90 is controlled to be 15±2μm, then the crystals are separated by using a horizontal siphon centrifuge (rotating speed is 3000rpm), the obtained wet crystals are dried by using a fluidized bed dryer (using hot air at 40°C) to obtain purified phytosterol;

[0119] (4) The phytosterol obtained in step (3) is mixed with silicon oil D5 at a mass ratio of 1:3 and put into a high-temperature resistant reaction kettle, stirred at 90°C for 30min to form a homogeneous transparent solution;

[0120] The crude isostearic acid was pumped into a vacuum dehydration kettle, and was subjected to vacuum dehydration at 120°C and -0.095 MPa for 2 h, with the moisture content monitored by an online moisture meter to be less than or equal to 0.05%, to ensure the subsequent reaction efficiency. Then, 3% of food-grade activated clay based on the mass of the isostearic acid was added for decolorization, and the mixture was stirred at 80°C for 30 min. Subsequently, the activated clay and impurities were removed by a plate-and-frame filter (0.2 μm filter core) to ensure that the Gardner color was less than or equal to 2. Then, the isostearic acid was transferred into a microwave reactor, and was subjected to microwave irradiation at 2450 MHz and 600 W for 15 min to promote the activation of the molecules and shorten the reaction time. Subsequently, the mixture was filtered using a candle filter (0.2 μm PTFE membrane) with the temperature controlled at 78°C to prevent crystallization of the fatty acid.

[0121] The homogeneous transparent solution of phytosterol was added with isostearic acid and a catalyst p-toluenesulfonic acid, the molar ratio of isostearic acid to phytosterol was 1:1.2, and the catalyst was added in an amount of 1.8% of the total mass of the reaction system, and the mixture was reacted at 115°C under nitrogen protection (nitrogen content <100 ppm) for 1.6 h, with stirring during the reaction at a stirring rate of 180 rpm to obtain a reaction product.

[0122] (5) The reaction product obtained in step (4) was subjected to first purification treatment, including: adding a 60°C Na2CO3 solution with a mass concentration of 1% into the reaction product for first neutralization to remove the catalyst to obtain a neutralized reaction product, then subjecting the neutralized reaction product to three-stage countercurrent water washing at a water washing temperature of 60°C to obtain a water-washed reaction product, the sulfonate content of the water-washed reaction product was <10 ppm, and the pH value was 7-8, then subjecting the water-washed reaction product to molecular distillation to recover silicone oil at a temperature of 180°C and a pressure of 5 Pa to obtain a reaction product after solvent removal, and the recovered solvent silicone oil was recycled after molecular sieve dehydration, the recovery rate of the silicone oil reached 95%, and finally the reaction product after solvent removal was subjected to vacuum flash evaporation at a temperature of 70°C and a pressure of 3 kPa to obtain a light yellow esterification product.

[0123] The esterification product was subjected to second purification treatment, including: adding a 65°C NaHCO3 solution with a mass concentration of 5% into the esterification product for second neutralization for 30 min to remove residual free acid, and adjusting the pH to 7.0±0.2, then subjecting the esterification product to three-stage countercurrent water washing at a water washing temperature of 80°C, with the volume ratio of the esterification product to water being 1:3, and each stage being kept for 15 min to obtain a washed esterification product; the washed esterification product was fed into a disc centrifuge, and was subjected to centrifugation at 3000 rpm to separate an organic phase containing the esterification product and an aqueous phase, then the organic phase was subjected to deep dehydration and drying by a molecular sieve dehydration tower to ensure that the moisture content was less than or equal to 0.05% to obtain a crude phytosterol ester product.

[0124] ​The crude phytosterol ester is subjected to a third purification treatment, including: subjecting the crude phytosterol ester to primary molecular distillation under the condition of a temperature of 180°C and a pressure of 10 Pa to obtain a primary heavy phase, and removing free fatty acids and light components such as low-boiling substances, and the light components are recovered by a cold trap to reduce the loss of main products; subjecting the obtained primary heavy phase to secondary molecular distillation under the condition of a temperature of 200°C and a pressure of 0.5 Pa, collecting the main products, and continuously collecting the main products through an automatic membrane scraping system to obtain phytosterol ester products and a secondary heavy phase; subjecting the obtained secondary heavy phase to tertiary distillation under the condition of a temperature of 220°C and a pressure of 0.1 Pa, cracking and removing high-molecular polymers and pigments (residue ≤ 3%), and subjecting the condensed waste gas to activated carbon adsorption treatment;

[0125] The phytosterol ester products are subjected to tertiary filtration, including: subjecting the phytosterol ester products obtained by secondary molecular distillation to primary filtration through a multi-bag parallel automatic back-flushing filter (configured with 5-μm-absolute-precision polypropylene melt-blown filter bags and a 304 stainless steel support net) at a temperature of 55°C, a pressure of 0.3 MPa, and a flow rate of 3 m 3 / (m 2 ·h); then, subjecting the phytosterol ester products to secondary filtration through an α-alumina ceramic membrane cross-flow system at a filtration precision of 0.1 μm, an effective area of 10 m 2 , a transmembrane pressure difference of 0.5 MPa, and a cross-flow speed of 3.5 m / s; and subjecting the phytosterol ester products to tertiary filtration through a 0.22-μm capsule filter, which is subjected to online steam sterilization at 121°C for 30 min to obtain final phytosterol ester products.

[0126] Example 2

[0127] The present embodiment provides a preparation method of phytosterol ester, which comprises the following steps:

[0128] (1) Put the soybean oil deodorized distillate into a stainless steel reaction kettle, preheat to 60°C, add a 10% NaOH solution and react for 0.5 h, then heat to a saponification reaction temperature of 82°C at a heating rate of 1°C / min, add a 10% NaOH solution and react for 2 h, and stir in the saponification reaction at a stirring rate of 80 rpm to reduce the generation of by-products; after the saponification reaction is completed, pump the saponification liquid into a settling tank through the bottom discharge valve, stand for stratification, remove the unsaponified oil and solid impurities by a hot pressure filter (operated at 80°C) to obtain hot pressure filter residue and saponification liquid, and recover residual sterols from the hot pressure filter residue by supercritical CO2 extraction, with a sterol yield increased by 14%, and the residue used as a raw material for biodiesel;

[0129] (2) The saponified liquid obtained in step (1) is pumped into the extraction vessel for extraction. The extraction temperature is 27°C. The mass ratio of the saponified liquid to the extractant 2-methyltetrahydrofuran is 1:4.5. The mixture is stirred at 60 rpm for 1 hour to promote the dissolution of non-saponifiables (sterols, vitamin E, etc.). After extraction, the mixture is allowed to stand and separate into layers. The lower aqueous phase (containing glycerol and salt) is discharged to the wastewater treatment system. The upper organic phase (containing sterols) is transferred to a multi-effect evaporator for evaporation and concentration. The extractant recovery rate is 90%. The initial purity of sterols is detected by HPLC. The insoluble matter in the obtained concentrate is removed by a plate and frame filter press (using a polypropylene filter element with a filtration accuracy of 0.5 μm) to obtain the extract concentrate.

[0130] (3) The extract concentrate obtained in step (2) is put into a stainless steel crystallization vessel, and industrial methanol is added. The mass ratio of the extract concentrate to methanol is 1:7. The solution is dissolved at 60°C to obtain a dissolved liquid. Then, activated carbon is added for decolorization for 30 min. The mass of activated carbon accounts for 2% of the mass of the dissolved liquid. Then, a plate and frame filter press (0.5 μm filter element) is used to remove impurities to obtain a filtrate. The obtained filtrate is transferred to an ultrasonic-microwave coupled crystallization system and cooled to -20°C at a rate of 1°C / min and held for 12 h. At the same time, 35kHz, 250W ultrasonic waves and 550W, 5s on / 5s off pulsed microwave radiation are applied to promote homogeneous nucleation and growth control of crystals. The final crystal particle size D 90 The sample was controlled at 15±2μm. Then, a horizontal siphon centrifuge (3000rpm) was used to separate the crystals. The resulting wet crystals were dried in a fluidized bed (using 40℃ hot air) to obtain purified phytosterols.

[0131] (4) The phytosterols obtained in step (3) are mixed with silicone oil D5 at a ratio of 1:3 (mass ratio) and added to a high-temperature resistant reactor. The mixture is stirred at 90°C for 30 minutes to form a homogeneous transparent solution.

[0132] Crude isostearic acid was pumped into a vacuum dehydration vessel and dehydrated under reduced pressure at 120℃ and -0.095MPa for 2 hours. The moisture content was monitored by an online moisture analyzer to ensure that the moisture content was ≤0.05% to ensure the efficiency of subsequent reactions. Then, food-grade activated clay (3% of the isostearic acid mass) was added for decolorization and stirred at 80℃ for 30 minutes. After that, a plate and frame filter press (0.2μm filter element) was used to remove the clay and impurities, ensuring that the Gardner color was ≤2. Then, the isostearic acid was transferred to a microwave reactor and microwave irradiated at 2500MHz and 500W for 15 minutes to promote molecular activation and shorten the reaction time. Finally, a candle filter (0.2μm PTFE membrane) was used for filtration, and the temperature was controlled at 78℃ to prevent fatty acid crystallization.

[0133] Isostearic acid and p-toluenesulfonic acid catalyst were added to a homogeneous transparent solution of phytosterols. The molar ratio of isostearic acid to phytosterols was 1:1.5, and the amount of catalyst added accounted for 1.5% of the total mass of the reaction system. The reaction was carried out at 110°C under nitrogen protection (nitrogen content <100ppm) for 2 hours. The mixture was stirred at a rate of 180 rpm during the reaction to obtain the reaction product.

[0134] (5) The reaction product obtained in step (4) is subjected to a first purification treatment, including: adding a 1% Na2CO3 solution at 60°C to the reaction product for first neutralization to remove the catalyst, obtaining a neutralized reaction product, and then subjecting the neutralized reaction product to a three-stage countercurrent water wash at 60°C to obtain a water-washed reaction product with a sulfonate content of <10ppm and a pH of 7-8. The water-washed reaction product is then subjected to molecular distillation to recover the silicone oil at 175°C and 3Pa to obtain a solvent-free reaction product. The recovered solvent silicone oil is then subjected to... The molecular sieve was dehydrated and recycled, and the recovery rate of silicone oil reached 93%. Finally, the reaction product after solvent removal was subjected to vacuum flash evaporation at a temperature of 75°C and a pressure of 4 kPa to obtain a light yellow esterified product.

[0135] The second purification process of the esterification product includes: adding a 5% NaHCO3 solution at 65°C to the esterification product for a second neutralization of 30 min to remove residual free acid, adjusting the pH to 7.0±0.2, and then performing a three-stage countercurrent water wash at 80°C with a volume ratio of esterification product to water of 1:3, with each stage lasting 15 min to obtain the washed esterification product; the washed esterification product is then sent to a disc centrifuge and centrifuged at 3000 rpm to separate the organic phase containing the esterification product and the aqueous phase; the organic phase is then deeply dehydrated and dried in a molecular sieve dehydration tower to ensure that the moisture content is ≤0.05% to obtain crude phytosterol ester;

[0136] The crude phytosterol esters undergo a third purification process, including: primary molecular distillation at 185°C and 8 Pa to obtain a primary heavy phase, removing free fatty acids and low-boiling components, which are then recovered via a cold trap to reduce the loss of the main product; secondary molecular distillation at 205°C and 0.3 Pa to collect the main product, which is continuously collected using an automatic scraping membrane system to obtain the phytosterol ester product and the secondary heavy phase; and tertiary distillation at 225°C and 0.05 Pa to pyrolyze and remove high molecular weight polymers and pigments (residue ≤3%), with the condensate treated by activated carbon adsorption.

[0137] The phytosterol ester product is subjected to three-stage filtration, including: the phytosterol ester product obtained by secondary molecular distillation is subjected to first-stage filtration by using a multi-bag parallel automatic back-flushing filter (4 μm absolute precision polypropylene melt-blown filter bag and 304 stainless steel support net are configured) at a temperature of 57 ℃, a pressure of 0.2 MPa and a flow rate of 3 m 3 / (m 2 ·h); then, the phytosterol ester product is subjected to second-stage filtration by using an α-alumina ceramic membrane cross-flow system at a filtration precision of 0.1 μm, an effective area of 10 m 2 , a transmembrane pressure difference of 0.6 MPa and a cross-flow speed of 3.7 m / s; and the phytosterol ester product is subjected to third-stage filtration by using a 0.25 μm capsule filter, which is subjected to online steam sterilization at 121 ℃ for 30 min, to obtain a phytosterol ester final product.

[0138] Example 3

[0139] The present embodiment provides a preparation method of a phytosterol ester, which comprises the following steps:

[0140] (1) The soybean oil deodorization distillate is put into a stainless steel reaction kettle, preheated to 60 ℃, and a 10% NaOH solution is added and reacted for 0.5 h, then the temperature is raised to the saponification reaction temperature of 82 ℃ at a rate of 1 ℃ / min, and a 10% NaOH solution is added and reacted for 2 h, the saponification reaction is carried out with stirring at a stirring rate of 80 rpm to reduce the generation of by-products, after the saponification reaction is completed, the saponification liquid is pumped into a settling tank through the bottom discharge valve, and is allowed to stand and separate, a hot pressure filter (operated at 80 ℃) is used to remove unsaponifiable oil and solid impurities, to obtain hot pressure filter residue and saponification liquid, the hot pressure filter residue is subjected to supercritical CO2 extraction to recover residual sterols, the sterol yield is increased by 13.8%, and the residue is used as a biodiesel raw material;

[0141] (2) The saponification liquid obtained in step (1) is pumped into an extraction kettle for extraction, the extraction temperature is 28 ℃, the mass ratio of the saponification liquid to the extractant 2-methyltetrahydrofuran is 1:4, and the stirring speed is 60 rpm for 1 h to promote the dissolution of non-saponifiable substances (sterols, vitamin E, etc.), after extraction, the liquid is allowed to stand and separate, the lower water phase (containing glycerol and salt) is discharged to a wastewater treatment system, and the upper organic phase (containing sterols) is transferred into a multi-effect evaporator for evaporation and concentration, the extractant recovery rate is 89%, the sterol initial purity is detected by HPLC, and the insoluble substances in the concentrated liquid are removed by using a plate and frame filter press (a polypropylene filter core with a filtration precision of 0.5 μm is used) to obtain an extraction concentrated liquid;

[0142] (3) The extraction concentrate obtained in step (2) is put into a stainless steel crystallization kettle, industrial methanol is added, the mass ratio of the extraction concentrate to methanol is 1:8, dissolution is carried out at 65°C to obtain a dissolved feed liquid, then activated carbon is added for decolorization for 30 min, the mass of the activated carbon accounts for 2% of the mass of the dissolved feed liquid, then a plate and frame filter press (0.5 μm filter core) is used to remove impurities to obtain a filtrate; the obtained filtrate is transferred to an ultrasonic-microwave coupled crystallization system, cooling is carried out at a rate of 1°C / min to -20°C for 16 h, while 45 kHz, 150 W ultrasonic waves and 650 W, 5 s on / 5 s off pulsed microwave radiation are applied to promote crystal homogeneous nucleation and growth regulation, and finally the crystal particle size D 90 is controlled at 15±2 μm, then a horizontal siphon centrifuge (rotating speed is 3000 rpm) is used to separate the crystals, and the obtained wet crystals are dried through a fluidized bed (hot air at 40°C) to obtain purified phytosterols;

[0143] (4) The phytosterols obtained in step (3) are mixed with silicon oil D5 at a mass ratio of 1:3 and put into a high-temperature resistant reaction kettle, stirring is carried out at 90°C for 30 min to form a homogeneous transparent solution;

[0144] The crude isostearic acid is pumped into a vacuum dehydration kettle, dehydration is carried out at 120°C and -0.095 MPa for 2 h, the moisture mass percentage is monitored through an online water content tester to be ≤0.05%, and the subsequent reaction efficiency is ensured, then food-grade activated clay accounting for 3% of the mass of the isostearic acid is added for decolorization, stirring is carried out at 80°C for 30 min, then a plate and frame filter press (0.2 μm filter core) is used to remove the clay and impurities to ensure that the Gardner color is ≤2, then the isostearic acid is transferred into a microwave reactor, microwave radiation treatment is carried out at 2400 MHz and 700 W for 15 min to promote molecular activation and shorten the reaction time, then a candle filter (0.2 μm PTFE membrane) is used for filtration, and the temperature is controlled at 78°C to prevent crystallization of fatty acids;

[0145] The isostearic acid and the catalyst p-toluenesulfonic acid are added to the homogeneous transparent solution of the phytosterols, the molar ratio of the isostearic acid to the phytosterols is 1:2, and the catalyst is added in an amount accounting for 2% of the total mass of the reaction system, reaction is carried out at 120°C under nitrogen protection (nitrogen content <100 ppm) for 1.5 h, stirring is carried out during the reaction, and the stirring rate is 180 rpm to obtain a reaction product;

[0146] (5) the reaction product obtained in step (4) is subjected to first purification treatment, comprising: adding a 60℃ Na2CO3 solution with a mass concentration of 1% to the reaction product to remove the catalyst by first neutralization to obtain a neutralized reaction product, then performing three-stage countercurrent water washing on the neutralized reaction product, with a water washing temperature of 60℃ to obtain a water-washed reaction product, the sulfonate content of which is <10 ppm and the pH value is 7-8, and then performing molecular distillation on the water-washed reaction product to recover silicone oil, at a temperature of 185℃ and a pressure of 4 Pa, to obtain a reaction product after solvent removal, and the recovered solvent silicone oil is subjected to molecular sieve dehydration and recycled, and the recovery rate of silicone oil reaches 89%, and finally the reaction product after solvent removal is subjected to vacuum flash evaporation, at a temperature of 80℃ and a pressure of 2 kPa, to obtain a light yellow esterification product;

[0147] the esterification product is subjected to second purification treatment, comprising: adding a 65℃ NaHCO3 solution with a mass concentration of 5% to the esterification product to remove residual free acid by second neutralization for 30 min, adjusting the pH to 7.0±0.2, then performing three-stage countercurrent water washing, with a water washing temperature of 80℃, a volume ratio of the esterification product to water of 1:3 in water washing, and a residence time of 15 min per stage, to obtain a washed esterification product; the washed esterification product is fed into a disc centrifuge for centrifugation at 3000 rpm to separate an organic phase containing the esterification product and an aqueous phase, and then the organic phase is subjected to deep dehydration and drying in a molecular sieve dehydration tower to ensure that the moisture content is ≤0.05%, to obtain a phytosteryl ester crude product;

[0148] the phytosteryl ester crude product is subjected to third purification treatment, comprising: performing first-stage molecular distillation on the phytosteryl ester crude product at a temperature of 175℃ and a pressure of 10 Pa to obtain a first-stage heavy phase, remove free fatty acids and light components such as low-boiling substances, and recover the light components through a cold trap to reduce the loss of main products; performing second-stage molecular distillation on the obtained first-stage heavy phase at 195℃ and 0.7 Pa to collect the main products, and continuously collecting the main products through an automatic membrane scraping system to obtain a phytosteryl ester product and a second-stage heavy phase; performing third-stage distillation on the obtained second-stage heavy phase at a temperature of 215℃ and a pressure of 0.15 Pa to crack and remove high-molecular polymers and pigments (residue ≤3%), and adsorbing the condensed waste gas through activated carbon;

[0149] the phytosteryl ester product is subjected to three-stage filtration, comprising: performing first-stage filtration on the phytosteryl ester product obtained by second-stage molecular distillation through a multi-bag parallel automatic backflush filter (configured with a 3 μm absolute precision polypropylene melt-blown filter bag and a 304 stainless steel support net), at a temperature of 53℃, a pressure of 0.4 MPa, and a flow rate of 3 m 3 / (m 2·h); then sent to the α-alumina ceramic membrane cross-flow system for secondary filtration, the filtration accuracy is 0.1 μm, the 19-channel design is adopted, the effective area is 10 m 2 , the transmembrane pressure difference is 0.4 MPa, and the cross-flow speed is 3.3 m / s; the 0.2 μm capsule filter is selected for tertiary filtration, and the plant sterol ester final product is obtained by online steam sterilization at 121 ℃ for 30 min.

[0150] Example 4

[0151] The embodiment provides a preparation method of plant sterol ester, and the difference between the preparation method and the embodiment 1 is only that the temperature of the primary molecular distillation is 170 ℃.

[0152] Example 5

[0153] The embodiment provides a preparation method of plant sterol ester, and the difference between the preparation method and the embodiment 1 is only that the temperature of the primary molecular distillation is 190 ℃.

[0154] Example 6

[0155] The embodiment provides a preparation method of plant sterol ester, and the difference between the preparation method and the embodiment 1 is only that the pressure of the primary molecular distillation is 6 Pa.

[0156] Example 7

[0157] The embodiment provides a preparation method of plant sterol ester, and the difference between the preparation method and the embodiment 1 is only that the pressure of the primary molecular distillation is 12 Pa.

[0158] Example 8

[0159] The embodiment provides a preparation method of plant sterol ester, and the difference between the preparation method and the embodiment 1 is only that the temperature of the secondary molecular distillation is 190 ℃.

[0160] Example 9

[0161] The embodiment provides a preparation method of plant sterol ester, and the difference between the preparation method and the embodiment 1 is only that the temperature of the secondary molecular distillation is 210 ℃.

[0162] Example 10

[0163] The embodiment provides a preparation method of plant sterol ester, and the difference between the preparation method and the embodiment 1 is only that the pressure of the secondary molecular distillation is 0.2 Pa.

[0164] Example 11

[0165] The present example provides a preparation method of phytosteryl ester, which is only different from example 1 in that the pressure of the secondary molecular distillation is 0.9 Pa.

[0166] Examples 12-13

[0167] The present examples 12-13 respectively provide a preparation method of phytosteryl ester, which is only different from example 1 in that no primary molecular distillation and secondary molecular distillation is respectively performed.

[0168] Examples 14-16

[0169] The present examples 14-16 respectively provide a preparation method of phytosteryl ester, which is only different from example 1 in that no primary filtration, secondary filtration and tertiary filtration is respectively performed.

[0170] The purity of phytosterol and the purity of phytosteryl ester in the above examples 1-3 are detected by HPLC, and the results are shown in Table 1; the conversion rate of phytosteryl ester is shown in Table 1.

[0171] The purity of phytosteryl ester in example 1 is compared with that in examples 14-16, and the results are shown in Table 2.

[0172] Table 1

[0173]

[0174] Table 2

[0175] Purity of phytosterol esters / % Example 1 98.5 Example 4 95.0 Example 5 94.2 Example 6 95.5 Example 7 94.0 Example 8 95.8 Example 9 93.8 Example 10 95.2 Example 11 93.5 Example 12 88.0 Example 13 87.2 Example 14 90.3 Example 15 89.5 Example 16 88.1

[0176] From the data in Tables 1-2, the following points can be seen:

[0177] (1) From the data in examples 1-3, it can be seen that, by using the preparation method provided by the present application under the optimal conditions, the purity of phytosterol can reach more than 98.8%, and under more optimal conditions, it can reach 99.2%; the purity of phytosteryl ester can reach more than 98.1%, and under more optimal conditions, it can reach 98.5%; the conversion rate of phytosteryl ester can reach more than 98.2%, and under more optimal conditions, it can reach 98.8%.

[0178] (2) From the data in example 1 and examples 4-11, it can be seen that, by optimizing the temperature and pressure of the primary molecular distillation and the secondary molecular distillation, the present application can further improve the purity of phytosteryl ester.

[0179] (3) From the comparison between example 1 and examples 12-16, it can be seen that, by using the combined operation of multi-stage molecular distillation and multi-stage filtration, the present application can further improve the purity of phytosteryl ester.

[0180] In summary, the preparation method provided by the application improves the purity of phytosterol esters through multi-stage purification treatment, molecular distillation and multi-stage filtration, optimizes the molecular structure, and makes the phytosterol esters more easily absorbed by the skin.

[0181] The applicant declares that the above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, and those skilled in the art should understand that any change or replacement within the technical scope disclosed by the application, which can be easily thought of by any person skilled in the art, falls within the protection scope and disclosure scope of the application.

Claims

1. A process for the preparation of a plant sterol ester, characterized in that, The preparation method comprises the following steps: (1) sequentially performing saponification reaction and solid-liquid separation on the plant oil deodorization distillate to obtain saponification liquid; (2) performing extraction on the saponification liquid obtained in step (1) to obtain organic phase, and sequentially performing evaporation concentration and solid-liquid separation on the organic phase to obtain extraction concentrated liquid; (3) sequentially performing dissolution, decolorization and solid-liquid separation on the extraction concentrated liquid obtained in step (2) to obtain filtrate; and sequentially performing cooling crystallization, solid-liquid separation and drying on the filtrate to obtain purified phytosterol; (4) performing esterification reaction on the phytosterol obtained in step (3) to obtain reaction product; (5) sequentially performing first purification treatment, second purification treatment and third purification treatment on the reaction product obtained in step (4) to obtain phytosterol ester product.

2. The production method according to claim 1, characterized by, The temperature of the saponification reaction in step (1) is 80-85℃; Preferably, the time of the saponification reaction is 1.5-2h; Preferably, the temperature of the extraction in step (2) is 25-30℃; Preferably, the time of the extraction is 1-2h; Preferably, the extractant used in the extraction comprises 2-methyltetrahydrofuran; Preferably, the mass ratio of saponification liquid to extractant in the extraction is 1:(4-5).

3. The production method according to claim 1 or 2, characterized by, Alcohol is added in the dissolution in step (3); Preferably, the alcohol comprises methanol; Preferably, the mass ratio of the extraction concentrated liquid to methanol is 1:(6-8); Preferably, the temperature of the dissolution is 60-70℃; Preferably, the decolorization comprises: mixing the solution after dissolution with activated carbon; Preferably, the mass of the activated carbon accounts for 1.5-2.5% of the mass of the solution after dissolution; Preferably, the time of the decolorization is 20-30min; Preferably, the cooling rate of the cooling crystallization is 0.5-1.5℃ / min; Preferably, the final temperature of the cooling crystallization is-15 to-20℃; Preferably, the crystallization time at the final temperature of the cooling crystallization is 12-16h; Preferably, ultrasonic wave and / or pulsed microwave radiation are applied in the process of the cooling crystallization; Preferably, the frequency of the ultrasonic wave is 35-45kHz; Preferably, the power of the ultrasonic wave is 150-250W; Preferably, the power of the pulsed microwave radiation is 550-650W.

4. The production method according to any one of claims 1 to 3, characterized by, Raw materials used in the esterification reaction in step (4) further comprise isostearic acid and catalyst; Preferably, the catalyst comprises p-toluenesulfonic acid; Preferably, the isostearic acid is subjected to microwave activation before the esterification reaction; Preferably, the power of the microwave activation is 500-700W; Preferably, the frequency of the microwave activation is 2400-2500MHz; Preferably, the time of the microwave activation is 10-20min.

5. The preparation method according to claim 4, characterized in that, Phytosterol is mixed with solvent before the esterification reaction; Preferably, the solvent comprises silicone oil; Preferably, the molar ratio of the isostearic acid to phytosterol is 1:(1-2); Preferably, the added amount of the catalyst accounts for 1.5-2% of the total mass of the reaction system; Preferably, the temperature of the esterification reaction is 110-120℃; Preferably, the time of the esterification reaction is 1.5-2h; Preferably, the esterification reaction is carried out under nitrogen protection.

6. The method of any one of claims 1-5, wherein, The first purification treatment in step (5) comprises: subjecting the reaction product to first neutralization to remove the catalyst to obtain a neutralized reaction product, then subjecting the neutralized reaction product to three-stage countercurrent water washing to obtain a water-washed reaction product, then subjecting the water-washed reaction product to molecular distillation to recover silicone oil to obtain a solvent-removed reaction product, and finally subjecting the solvent-removed reaction product to reduced-pressure flash evaporation to obtain an esterification product; Preferably, the neutralizing agent used in the first neutralization comprises a sodium carbonate solution; Preferably, the temperature of the first neutralization is 60-70℃; Preferably, the water washing temperature in the three-stage countercurrent water washing in the first purification treatment is 60-70℃; Preferably, the sulfonic acid root content after the three-stage countercurrent water washing in the first purification treatment is <10ppm; Preferably, the pH value after the three-stage countercurrent water washing in the first purification treatment is 7-8; Preferably, the temperature of the molecular distillation in the first purification treatment is 175-185℃; Preferably, the pressure of the molecular distillation in the first purification treatment is 3-5Pa; Preferably, the temperature of the reduced-pressure flash evaporation is 70-80℃; Preferably, the pressure of the reduced-pressure flash evaporation is 2-4kPa.

7. The production method according to claim 6, wherein The second purification treatment in step (5) comprises: subjecting the esterification product to second neutralization to remove residual free acid, then subjecting it to three-stage countercurrent water washing to obtain a washed esterification product; subjecting the washed esterification product to centrifugation to separate an organic phase containing the esterification product and an aqueous phase, and then subjecting the organic phase to dehydration drying to obtain a phytosterol ester crude product; Preferably, the neutralizing agent used in the second neutralization comprises a sodium bicarbonate solution; Preferably, the temperature of the second neutralization is 65-75℃; Preferably, the end-point pH value of the second neutralization is 6.8-7.2; Preferably, the time of the second neutralization is 23-30min; Preferably, the water washing temperature in the three-stage countercurrent water washing in the second purification treatment is 70-85℃; Preferably, the mass percentage content of water in the organic phase after the dehydration drying is ≤0.05%.

8. The method of claim 7, wherein, The third purification treatment in step (5) comprises three-stage molecular distillation, i.e., subjecting the phytosterol ester crude product to first-stage molecular distillation to obtain a first-stage heavy phase, subjecting the obtained first-stage heavy phase to second-stage molecular distillation to obtain a phytosterol ester product and a second-stage heavy phase, and subjecting the obtained second-stage heavy phase to third-stage distillation to crack and remove heavy components; Preferably, the temperature of the first-stage molecular distillation is 175-185℃; Preferably, the pressure of the first-stage molecular distillation is 8-10Pa; Preferably, the temperature of the second-stage molecular distillation is 195-205℃; Preferably, the pressure of the second-stage molecular distillation is 0.3-0.7Pa; Preferably, the temperature of the third-stage molecular distillation is 215-225℃; Preferably, the pressure of the third-stage molecular distillation is 0.05-0.15Pa; Preferably, the third purification treatment further comprises three-stage filtration, i.e., subjecting the phytosterol ester product obtained from the second-stage molecular distillation to first-stage filtration, second-stage filtration and third-stage filtration in sequence; Preferably, the first-stage filtration adopts a multi-bag parallel automatic backflushing filter; Preferably, the precision of the primary filtration is 3-5 μm; Preferably, the temperature of the primary filtration is 53-57℃; Preferably, the pressure of the primary filtration is 0.2-0.4 MPa; Preferably, the precision of the secondary filtration is 0.08-0.12 μm; Preferably, the secondary filtration adopts an α-alumina ceramic membrane cross-flow system; Preferably, the transmembrane pressure difference of the α-alumina ceramic membrane cross-flow system is 0.4-0.6 MPa; Preferably, the cross-flow velocity of the α-alumina ceramic membrane cross-flow system is 3.3-3.7 m / s; Preferably, the precision of the tertiary filtration is 0.2-0.25 μm; Preferably, the tertiary filtration adopts a capsule filter; Preferably, online steam sterilization is performed in the tertiary filtration.

9. A phytosteryl ester, characterized in that, The phytosterol ester is obtained by the method for preparing phytosterol ester according to any one of claims 1-8.

10. Use of a plant sterol ester as claimed in claim 9, characterized in that, The phytosterol ester is used for skin care products.

Images