A kind of fucoxanthin and its preparation method and application

Abstract

The present invention relates to a fucoxanthin and a preparation method and application thereof, and belongs to the technical field of plant extraction and processing. The preparation method comprises: crushing the triangular brown finger algae to obtain triangular brown finger algae powder; extracting the triangular brown finger algae powder with a non-polar solvent and collecting the extract residue; extracting the extract residue with an ethanol aqueous solution and centrifuging to obtain an extract; concentrating the extract and adding petroleum ether, cooling and crystallizing, filtering to remove impurities, and collecting liquid phase substances; subjecting the liquid phase substances to crystallization, filtering, drying, and recrystallization treatment to obtain crystalline fucoxanthin. The method extracts and purifies the fucoxanthin in the triangular brown finger algae by using a solvent extraction separation method to remove impurities such as fat-soluble and chlorophyll, avoids the use of purification methods such as chromatographic separation / column chromatography, reduces production costs, and improves production capacity.

Description

Technical Field

[0001] The invention belongs to the technical field of plant extraction and processing, and specifically relates to fucoxanthin and a preparation method and application thereof. Background Art

[0002] Fucoxanthin is a xanthophyll carotenoid naturally found in algae and marine organisms. It is widely used in medicine, skin care and beauty products, and health products because of its anti-tumor, anti-inflammatory, antioxidant, neuroprotective, and weight loss effects. However, the current industrial production of fucoxanthin is limited by its complex extraction and purification process and high cost.

[0003] At present, fucoxanthin is mostly extracted from brown algae (such as kelp, Sargassum fusiformis) or microalgae (such as triangular brown finger algae, golden audusa, etc.), and the extraction process is usually based on solvent extraction. However, the content of fucoxanthin in algae is low (for example, the dry basis content of fucoxanthin in microalgae is only 1.1% to 1.5%), resulting in a large amount of impurities in the liquid after extraction, including protein, fat, chlorophyll, DHA, EPA and polysaccharides, etc. These impurities seriously affect the purity and quality of the fucoxanthin product. Therefore, further purification process becomes a key step.

[0004] The purification methods reported in the prior art are mainly chromatographic separation techniques, such as silica gel column chromatography, high performance liquid chromatography (HPLC), thin layer chromatography (TLC), high speed countercurrent chromatography and macroporous resin adsorption chromatography. Although these methods can effectively improve the purity of fucoxanthin, they have significant limitations, such as complex operation, high cost, and low production capacity, which are difficult to meet the needs of industrial production.

[0005] For example, patent document CN114560797A discloses a method for extracting fucoxanthin from brown algae, and high-purity crystals are obtained by ethanol extraction, alkali saponification and column chromatography purification. However, its column chromatography process is complicated and costly. Similarly, patent documents CN107382912B and CN103232552B also use macroporous resin chromatography and silica gel chromatography to purify the extracts, but these methods all rely on solvent separation or column chromatography operations, and industrial applications are limited. In addition, documents CN104003962B and CN103965143A separate fucoxanthin by redissolving in organic solvents and combining n-hexane / ethyl acetate elution or high-performance liquid chromatography, but still cannot overcome the bottlenecks of high cost and large-scale application.

[0006] It can be seen that in the prior art, although there are various methods for purifying fucoxanthin, they all have the problems of high cost, low production capacity and difficulty in industrialization. Therefore, developing an efficient, low-cost fucoxanthin extraction and purification process suitable for large-scale industrial production has become a technical problem that needs to be solved urgently. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the first aspect of the present invention provides a low-cost and easy industrial production method for preparing fucoxanthin.

[0008] The second aspect of the present invention provides high-purity fucoxanthin prepared by the preparation method.

[0009] According to a first aspect of the present invention, a method for preparing fucoxanthin is provided, comprising the steps of:

[0010] (1) using an ultrafine grinder to grind the triangular kelp at a temperature of -10°C to -20°C to obtain triangular kelp powder;

[0011] (2) extracting the P. triangularis powder with a non-polar solvent and collecting the residue; the non-polar solvent comprises at least one of petroleum ether, n-hexane and cyclohexane;

[0012] (3) extracting the residue with an ethanol aqueous solution and centrifuging to obtain an extract;

[0013] (4) concentrating the extract to obtain a concentrated solution, adding petroleum ether to the concentrated solution, cooling the temperature to 0°C-5°C for 1.5-2.5 hours to allow impurities to crystallize, filtering to remove impurities, and collecting liquid phase substances;

[0014] (5) The liquid phase material is evaporated and crystallized, filtered, and dried to obtain fucoxanthin.

[0015] In some of the embodiments, in step (1), the triangular kelp is crushed using an ultrafine grinder at a temperature of -10°C to -20°C, preferably under nitrogen conditions, and the crushing time of the ultrafine grinder is 12-20 minutes to obtain triangular kelp powder.

[0016] In some embodiments, in step (2), during the extraction, the mass volume ratio of the triangular phytodactylum powder to the non-polar solvent is 1: (4-5) g / mL. That is, 1 g of triangular phytodactylum powder is added with 4-5 mL of non-polar solvent, and those skilled in the art can scale up accordingly.

[0017] In some embodiments, the extraction temperature in step (2) is 40° C. to 55° C., and the number of extractions is preferably 2-4 times, with each extraction lasting 0.8 to 1.5 h.

[0018] In some embodiments, in step (3), the concentration of the ethanol solution is 80-95% (v / v), and the preferred ethanol concentration is 85-95% (v / v);

[0019] and / or, the mass volume ratio of the raffinate to the ethanol solution is 1:(4-5) g / mL,

[0020] And / or, the temperature during extraction is 40° C. to 55° C., preferably the number of extractions is 2-4 times, and the time of each extraction is 0.8 to 1.5 hours.

[0021] In some embodiments, in step (4), the concentration is reduced pressure concentration, and the temperature of the reduced pressure concentration is 55° C. to 65° C.;

[0022] And / or, the vacuum degree of the reduced pressure concentration is -0.080Mpa to -0.095Mpa;

[0023] And / or, the mass volume ratio of the Phaeodactylum tricornutum powder to the concentrated solution is 1:(1-4) g / mL. That is, the extract is concentrated to the above mass volume ratio and the reduced pressure concentration is stopped.

[0024] In some embodiments, in step (4), the mass volume ratio of the Phaeodactylum tricornutum powder to the petroleum ether is 1:(1-4) g / mL.

[0025] In some of the embodiments, in step (5), the heating temperature of the evaporation crystallization is 50° C. to 60° C., and / or the vacuum degree of the evaporation crystallization is -0.080 MPa to -0.095 MPa.

[0026] In some embodiments, the preparation method further comprises step (6), adding ethanol solution to dissolve the fucoxanthin obtained in step (5), slowly adding water for recrystallization, wherein the water is deionized water, filtering and drying to obtain high-purity crystalline fucoxanthin.

[0027] In some of the embodiments, in step (6), the concentration of the ethanol solution is 95%-100% (v / v), and the mass volume ratio of the added amount of ethanol solution to fucoxanthin is 1:(40-70) g / mL.

[0028] In some embodiments, in the slow water addition recrystallization in step (6), the water is deionized water, and the amount of water added is such that the concentration of the ethanol solution is adjusted to 30-35% (v / v) after adding water.

[0029] According to a second aspect of the present invention, there is provided high-purity fucoxanthin prepared by any of the preparation methods described above.

[0030] The above-mentioned fucoxanthin is used in food, health products, medicine, cosmetics and feed.

[0031] Beneficial effects of the present invention:

[0032] The present invention provides a method for preparing fucoxanthin, which extracts and purifies fucoxanthin from Phaeodactylum triangularis powder by solvent extraction and separation, removes impurities such as fat-soluble and chlorophyll, avoids the use of purification methods such as chromatographic separation / column chromatography, reduces production costs, and improves production capacity. The method is suitable for large-scale industrial production of fucoxanthin.

[0033] The fucoxanthin obtained by the method of the invention has high purity and high content yield. The fucoxanthin content is 70%-90% as determined by high performance liquid chromatography. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a microscopic image of the triangular algae.

[0035] Figure 2 This is the high-purity crystalline fucoxanthin prepared in Example 1.

[0036] Figure 3 This is the liquid phase spectrum of the crystalline fucoxanthin obtained in Example 1.

[0037] Figure 4 It is an impurity precipitated from the crystallization of petroleum ether. DETAILED DESCRIPTION

[0038] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0039] In the examples, the test methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0040] A method for preparing fucoxanthin, comprising the steps of:

[0041] (1) using an ultrafine grinder to grind the triangular kelp at a temperature of -10°C to -20°C to obtain triangular kelp powder;

[0042] (2) extracting the P. triangularis powder with a non-polar solvent and collecting the residue; the non-polar solvent comprises at least one of petroleum ether, n-hexane and cyclohexane;

[0043] (3) extracting the residue with an ethanol aqueous solution and centrifuging to obtain an extract;

[0044] (4) concentrating the extract to obtain a concentrated solution, adding petroleum ether to the concentrated solution, cooling the solution to 0°C-5°C for 1.5-2.5 hours to allow impurities to crystallize, filtering to remove impurities, and collecting liquid phase substances;

[0045] (5) evaporating and crystallizing the liquid phase material, filtering, and drying to obtain fucoxanthin (crude product);

[0046] (6) Add fucoxanthin (crude product) into ethanol solution to dissolve it, slowly add water to recrystallize it, filter and dry it to obtain high-purity crystalline fucoxanthin.

[0047] In the prior art, the sources of fucoxanthin extraction are generally large algae (brown algae) and microalgae. Generally speaking, large algae grow slowly and have high extraction costs, while microalgae such as diatoms grow fast, have high photosynthetic efficiency, and controllable culture conditions. Their fucoxanthin content is 1 to 3 orders of magnitude higher than that of large algae, so microalgae are currently used to extract fucoxanthin. Secondly, many kinds of marine microalgae contain fucoxanthin, such as Sargassum, copper algae, and Isochrysis spherica.

[0048] Phaeodactylum tricornutum is a marine unicellular microalgae belonging to the phylum Bacillariophyta, class Pinnata, order Phaeodactylum, family Phaeodactylum, genus Phaeodactylum. It has three different morphologies: ovate, fusiform, and triradiate, which can change under different environmental conditions.

[0049] The main reason for choosing Phaeodactylum tricornutum in this application is that it has the advantages of fast growth, high photosynthetic efficiency, high fucoxanthin content, large-scale cultivation, no occupation of arable land, and almost no seasonal influence. It is considered to be a high-quality algae source for sustainable production of fucoxanthin, and industrial cultivation has been achieved. Figure 1 .

[0050] The preparation method of the present application uses P. triangularis as a raw material, does not require macroporous resin chromatography or silica gel chromatography to purify the extract, and does not require high performance liquid chromatography to separate fucoxanthin. Only a solvent extraction and separation method is used to achieve the crude extraction and purification of fucoxanthin in P. triangularis, and obtain high-purity fucoxanthin crystals.

[0051] However, the impurities extracted from large brown algae such as kelp are different from those of the triangular brown algae used in this application, and the subsequent purification methods are also quite different, so the technical solution of this application cannot be applied.

[0052] The raffinate, also known as the raffinate phase, refers to the liquid phase of the mixture left after the solvent extraction process. It includes all substances not extracted by the solvent and a small amount of solvent dissolved in it during the extraction process. It is commonly known as the residue.

[0053] In some of the embodiments, in step (1), the triangular kelp is crushed using an ultrafine grinder at a temperature of -10°C to -20°C, preferably under nitrogen conditions, and the crushing time of the ultrafine grinder is 12-20 minutes to obtain triangular kelp powder.

[0054] Since fucoxanthin has poor stability, the heat generated during the crushing process will cause the loss of fucoxanthin content, so low-temperature ultrafine crushing is adopted.

[0055] The purpose of ultrafine grinding is to break the wall. The reason for choosing ultrafine grinding is that the ultrafine grinder has good grinding effect, short time, temperature control, nitrogen flow, suitable for heat-sensitive and oxygen-sensitive materials, and avoids the loss of fucoxanthin.

[0056] There is no limit on screening after crushing, mainly because the algae powder itself is very fine. Ultrafine grinding destroys the cell wall through vibration and friction and shearing of metal rods. By limiting the crushing time of the ultrafine grinder, the triangular brown finger algae can achieve a certain cell wall breaking rate.

[0057] In some embodiments, in step (2), the non-polar solvent includes at least one of petroleum ether, n-hexane and cyclohexane.

[0058] The non-polar solvent is a low polar solvent, which refers to a solvent with a lower molecular polarity. DHA, EPA and other substances in the triangular phytoplankton are firstly extracted.

[0059] In some embodiments, in step (2), during extraction, the mass volume ratio of the Phaeodactylum tricornutum powder to the non-polar solvent is 1:(4-5) g / mL.

[0060] In some embodiments, the extraction temperature in step (2) is 40° C. to 55° C., and the number of extractions is preferably 2-4 times, with each extraction lasting 0.8 to 1.5 h.

[0061] In some of the embodiments, in step (3), the concentration of the ethanol solution is 80-95% (v / v), and the preferred ethanol concentration is 85-95% (v / v).

[0062] Ethanol (C2H5OH) aqueous solution is widely used due to its good solubility and volatility. It is able to dissolve many organic compounds and, due to its low boiling point, is easily volatile, which makes it very useful for cleaning and disinfection. In addition, ethanol aqueous solution is also a common solvent in many chemical experiments because it can dissolve a variety of substances and is relatively inert to many chemical reactions.

[0063] The present application preferably uses an ethanol (C2H5OH) aqueous solution to dissolve and extract the triangular phycodactylum powder treated with a low-polarity solvent, so that the fucoxanthin in the triangular phycodactylum can be well extracted, and impurities such as chlorophyll are also included. It is not easy to extract fucoxanthin when the concentration of the ethanol solution is lower than 80%.

[0064] In some embodiments, in step (3), the mass volume ratio of the raffinate to the ethanol solution is 1: (4-5) g / mL, and / or the temperature during extraction is 40°C to 55°C, preferably the number of extractions is 2-4 times, and the time of each extraction is 0.8-1.5 hours. If the temperature is not within this range, the extraction yield of fucoxanthin will be affected to a certain extent.

[0065] In some embodiments, in step (4), the concentration is reduced pressure concentration, the temperature of the reduced pressure concentration is 55°C to 65°C, and / or the vacuum degree of the reduced pressure concentration is -0.080Mpa

[0066] ~-0.095Mpa; and / or, the mass volume ratio of the triangular kelp powder to the concentrated solution is 1:(1~4)g / mL.

[0067] In some embodiments, in step (4), the mass volume ratio of the Phaeodactylum tricornutum powder to the petroleum ether is 1:(1-4) g / mL.

[0068] The crystals in this step are impurity chlorophyll, mainly chlorophyll A and chlorophyll B. The photos of impurities precipitated from petroleum ether crystals are shown in Figure 4 The present invention replaces the column chromatography of the prior art by optimizing petroleum ether and cooling crystallization. However, other organic solvents cannot achieve the effect of the present invention when replacing petroleum ether.

[0069] In some of the embodiments, in step (5), the heating temperature of the evaporation crystallization is 50° C. to 60° C., and / or the vacuum degree of the evaporation crystallization is -0.080 MPa to -0.095 MPa.

[0070] In some of the embodiments, in step (6), the concentration of the ethanol solution is 95%-100% (v / v), and the mass volume ratio of the added amount of ethanol solution to fucoxanthin is 1:(40-70) g / mL.

[0071] In some embodiments, in the slow water addition recrystallization in step (6), the water is deionized water, and the amount of water added is such that the concentration of the ethanol solution is adjusted to 30-35% (v / v) after adding water.

[0072] By utilizing the polarity difference between 95%-100% ethanol solution and deionized water, fucoxanthin crystals are precipitated earlier, and a small amount of impurities in the crude fucoxanthin crystals are further removed.

[0073] The fucoxanthin prepared by the preparation method described in any one of the above items.

[0074] The fucoxanthin is used in food, health products, medicines, cosmetics and feed.

[0075] The concentration of the ethanol solution used in the examples and comparative examples is in volume percentage. Chemicals and reagents such as n-hexane, petroleum ether, and acetone are all commercially available products of analytical grade.

[0076] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0077] Example 1

[0078] A method for extracting and purifying high-purity fucoxanthin, specifically comprising the following steps:

[0079] (1) Phaeochromis triangularis (with a fucoxanthin content of about 1%) was crushed using an ultrafine grinder at -20°C for 15 min to obtain algae powder after wall breaking;

[0080] (2) Weigh 100 g of broken algae powder, add 400 ml of n-hexane, extract at 50°C, extract for 1 h three times, centrifuge, and collect the residue;

[0081] (3) The residue was extracted with 400 ml of 92% (v / v) ethanol solution at 50° C. for 1 h each time for a total of 3 times, and then centrifuged to obtain an extract;

[0082] (4) The extract was concentrated to 200 ml at 60°C and vacuum degree -0.09 MPa, 400 ml of petroleum ether was added, the temperature was cooled to 0°C for crystallization for 2 h, impurities were removed by filtration, and the liquid phase was collected;

[0083] (5) The liquid phase was evaporated and crystallized at 60° C. and vacuum degree of -0.09 MPa, filtered, and vacuum dried at 50° C. for 8 h to obtain 1.09 g of crude fucoxanthin crystals. The fucoxanthin content was 75.67% as determined by high performance liquid chromatography.

[0084] (6) After the crude fucoxanthin crystals were dissolved in 50 ml of 95% (v / v) ethanol, 108 ml of deionized water was slowly added and filtered to obtain 0.95 g of fucoxanthin crystals. Figure 2 The fucoxanthin content was 85.74% as determined by high performance liquid chromatography. Figure 3 shown.

[0085] Example 2

[0086] A method for extracting and purifying high-purity fucoxanthin, specifically comprising the following steps:

[0087] (1) Phaeochromis triangularis (with a fucoxanthin content of about 1%) was crushed using an ultrafine grinder at -10°C for 15 min to obtain algae powder after wall breaking;

[0088] (2) Weigh 100 g of broken algae powder, add 500 ml of n-hexane, extract at 55°C, extract 3 times for 1 h each time, centrifuge, and collect the residue;

[0089] (3) The residue was extracted with 500 ml of 90% ethanol solution at 55° C. for 1 h each time for 3 times, and then centrifuged to obtain an extract;

[0090] (4) The extract was concentrated to 200 ml at 60°C and vacuum degree -0.09 MPa, 300 ml of petroleum ether was added, the temperature was cooled to 3°C for crystallization for 2 h, impurities were removed by filtration, and the liquid phase was collected;

[0091] Among them, the impurities precipitated from the crystallization of petroleum ether are shown in the following figure: Figure 4 .

[0092] (5) The liquid phase was evaporated and crystallized at 60° C. and vacuum degree of −0.09 MPa, filtered, and vacuum dried at 50° C. for 8 h to obtain 1.13 g of crude fucoxanthin crystals. The fucoxanthin content was 73.12% as determined by high performance liquid chromatography.

[0093] (6) After the crude fucoxanthin crystals were dissolved in 50 ml of 95% ethanol, 108 ml of deionized water was slowly added and filtered to obtain 0.97 g of fucoxanthin crystals. The fucoxanthin content was 82.63% as determined by high performance liquid chromatography.

[0094] Example 3

[0095] A method for extracting and purifying high-purity fucoxanthin, specifically comprising the following steps:

[0096] (1) Phaeochromis triangularis (with a fucoxanthin content of about 1%) was crushed using an ultrafine grinder at -20°C for 15 min to obtain algae powder after wall breaking;

[0097] (2) Weigh 100 g of broken algae powder, add 400 ml of n-hexane, extract at 50°C, extract for 1 h three times, centrifuge, and collect the residue;

[0098] (3) The residue was extracted with 400 ml of 80% ethanol solution at 55°C for 1 h each time for a total of 2 times, and then centrifuged to obtain an extract;

[0099] (4) The extract was concentrated to 300 ml at 65°C and vacuum degree -0.08 MPa, 300 ml of petroleum ether was added, the temperature was cooled to 5°C for crystallization for 2 h, impurities were removed by filtration, and the liquid phase was collected;

[0100] (5) The liquid phase was evaporated and crystallized at 60°C and vacuum degree of -0.08 MPa, filtered, and vacuum dried at 50°C for 8 h to obtain 1.10 g of fucoxanthin crystals, which was crude fucoxanthin. The fucoxanthin content was 70.19% as determined by high performance liquid chromatography.

[0101] (6) After the crude fucoxanthin crystals were dissolved in 45 ml of 95% ethanol, 100 ml of deionized water was slowly added and filtered to obtain 0.93 g of fucoxanthin crystals. The fucoxanthin content was 81.73% as determined by high performance liquid chromatography.

[0102] Example 4

[0103] A method for extracting and purifying high-purity fucoxanthin, specifically comprising the following steps:

[0104] (1) Phaeochromis triangularis (with a fucoxanthin content of about 1%) was crushed using an ultrafine grinder at -20°C for 15 min to obtain algae powder after wall breaking;

[0105] (2) Weigh 100 g of broken algae powder, add 500 ml of petroleum ether, extract at 55°C, extract 4 times for 1.2 h each time, centrifuge, and collect the residue;

[0106] (3) The residue was extracted with 500 ml of 95% ethanol solution at 50° C. for 1 h each time for a total of 4 times, and then centrifuged to obtain an extract;

[0107] (4) The extract was concentrated to 200 ml at 55°C and vacuum degree -0.095 MPa, 300 ml of petroleum ether was added, the temperature was cooled to 0°C for crystallization for 2 h, impurities were removed by filtration, and the liquid phase was collected;

[0108] (5) The liquid phase was evaporated and crystallized at 60° C. and vacuum degree of -0.09 MPa, filtered, and vacuum dried at 50° C. for 8 h to obtain 1.05 g of fucoxanthin crystals, which was crude fucoxanthin. The fucoxanthin content was 79.06% as determined by high performance liquid chromatography.

[0109] (6) After the crude fucoxanthin crystals were dissolved by adding 50 ml of anhydrous ethanol, 120 ml of deionized water was slowly added and filtered to obtain 0.95 g of fucoxanthin crystals. The fucoxanthin content was 86.32% as determined by high performance liquid chromatography.

[0110] Example 5

[0111] A method for extracting and purifying high-purity fucoxanthin, specifically comprising the following steps:

[0112] (1) Phaeochromis triangularis (with a fucoxanthin content of about 1%) was crushed using an ultrafine grinder at -20°C for 15 min to obtain algae powder after wall breaking;

[0113] (2) Weigh 100 g of broken algae powder, add 400 ml of cyclohexane, extract at 55°C, extract 4 times for 0.8 h each time, centrifuge, and collect the residue;

[0114] (3) The residue was extracted with 400 ml of 90% ethanol solution at 55°C for 1 h each time for 4 times, and then centrifuged to obtain an extract;

[0115] (4) The extract was concentrated to 200 ml at 55°C and vacuum degree -0.095 MPa, 300 ml of petroleum ether was added, the temperature was cooled to 3°C for crystallization for 2 h, impurities were removed by filtration, and the liquid phase was collected;

[0116] (5) The liquid phase was evaporated and crystallized at 50° C. and vacuum degree of -0.09 MPa, filtered, and vacuum dried at 50° C. for 8 h to obtain 1.1 g of fucoxanthin crystals, which was crude fucoxanthin. The fucoxanthin content was 73.21% as determined by high performance liquid chromatography.

[0117] (6) After the crude fucoxanthin crystals were dissolved in 55 ml of 95% ethanol, 120 ml of deionized water was slowly added and filtered to obtain 0.97 g of fucoxanthin crystals. The fucoxanthin content was 82.03% as determined by high performance liquid chromatography.

[0118] Comparative Example 1

[0119] Compared with the method of patent document CN114560797A.

[0120] CN114560797A discloses a fucoxanthin extraction process using ethanol to extract brown algae, wherein the crude product after extraction is purified by saponification and column chromatography to obtain fucoxanthin crystals. Although this method can obtain high-purity fucoxanthin, due to the use of saponification steps and column chromatography, the operation is complicated and the cost is high, and the production capacity is limited.

[0121] The present invention simplifies the extraction and purification steps, uses low-cost low-temperature crushing, non-polar solvent extraction and crystallization to purify, does not require a saponification process, and uses the method of adding an organic solvent petroleum ether to the concentrated solution and then cooling and crystallizing to remove impurities instead of traditional column chromatography, thereby improving production efficiency and reducing costs. Through this improvement, the present invention can achieve industrial production on a larger scale and can effectively improve the recovery rate of fucoxanthin.

[0122] Comparative advantages:

[0123] 1. Cost:

[0124] The extraction solvent and purification method of the present invention use low-temperature crushing, non-polar solvent extraction and crystallization, which greatly reduces the cost compared with the solvent and column chromatography in CN114560797A.

[0125] 2. Easy to operate:

[0126] The invention removes the saponification step, reduces the operation links, and has a simpler and easier process, which is suitable for large-scale production.

[0127] 3.Production efficiency:

[0128] The invention adds organic solvent petroleum ether to the concentrated liquid, then cools down the liquid for crystallization and impurity removal instead of column chromatography, thereby improving production efficiency and shortening production cycle.

[0129] Comparative Example 2

[0130] Compared with the method of patent document CN103232552B.

[0131] CN103232552B adopts a purification method of silica gel chromatography and organic solvent re-dissolution. Although it can obtain fucoxanthin with high purity, it uses a large amount of organic solvent and the operation steps are complicated, making it difficult to apply in large-scale production.

[0132] The present invention optimizes the extraction and purification process, simplifies the steps and reduces the use of organic solvents, and can obtain high-purity fucoxanthin crystals without silica gel chromatography, thereby reducing production costs.

[0133] Comparative advantages:

[0134] 1. Amount of organic solvent used: The amount of organic solvent used in the present invention is relatively small, which reduces solvent consumption and production costs compared to CN103232552B.

[0135] 2. Simplified steps: The present invention reduces the chromatography steps and does not use a complicated solvent re-dissolution process, making the operation easier.

[0136] 3. Production feasibility: Due to the simplified steps and low solvent usage, the process of the present invention is more suitable for large-scale industrial production.

[0137] Comparative Example 3

[0138] In step (1), the temperature of low-temperature ultrafine grinding is 10° C. Except for this temperature, steps (1) to (5) are the same as in Example 1.

[0139] The result is that 0.81 g of fucoxanthin crystals are obtained in step (5), which is crude fucoxanthin. The fucoxanthin content is 75.43% as determined by high performance liquid chromatography.

[0140] Step (6) After the crude fucoxanthin crystals are dissolved by adding 50 ml of 95% ethanol, 108 ml of deionized water is slowly added and filtered to obtain 0.7 g of fucoxanthin crystals. The fucoxanthin content is 84.62% as determined by high performance liquid chromatography.

[0141] The results showed that the yield of fucoxanthin crystal content was significantly reduced, indicating that there was content loss during the ultrafine grinding process.

[0142] Comparative Example 4

[0143] In step (4), petroleum ether was replaced by ethyl acetate in an equal amount. Except for this replacement, steps (1) to (5) were the same as in Example 1.

[0144] The result is that 0.54 g of fucoxanthin crystals are obtained in step (5), which is crude fucoxanthin. The fucoxanthin content is 62.5% as determined by high performance liquid chromatography.

[0145] Step (6) After the crude fucoxanthin crystals are dissolved by adding 50 ml of 95% ethanol, 108 ml of deionized water is slowly added and filtered to obtain 0.42 g of fucoxanthin crystals. The fucoxanthin content is 75.32% as determined by high performance liquid chromatography.

[0146] The present invention utilizes petroleum ether to cool and crystallize to remove chlorophyll impurities instead of column chromatography, while similar effects cannot be obtained under other solvents or temperatures.

[0147] Comparative Example 5

[0148] The crude fucoxanthin obtained in step (5) of Example 1 was measured by high performance liquid chromatography to show that the fucoxanthin content was 75.67%.

[0149] In step (6), an equal amount of acetone solution is used to replace the 95% ethanol solution. Specifically, after the crude fucoxanthin crystals are dissolved in 50 ml of acetone solution, 108 ml of deionized water is slowly added and filtered, resulting in 1.62 g of fucoxanthin crystals. The fucoxanthin content is 76.32% as determined by high performance liquid chromatography. This indicates that using acetone to replace the preferred ethanol solution of this application for recrystallization treatment does not significantly increase the content of fucoxanthin crystals.

[0150] It should be noted that the specific parameters or some reagents in the above embodiments are specific embodiments or preferred embodiments of the present invention, rather than limiting the present invention; those skilled in the art can make adaptive adjustments within the scope of the present invention.

Claims

1. A method for preparing fucoxanthin, characterized in that: Includes steps: (1) using an ultrafine grinder to grind the triangular kelp at a temperature of -10°C to -20°C to obtain triangular kelp powder; (2) extracting the P. triangularis powder with a non-polar solvent and collecting the residue; the non-polar solvent comprises at least one of petroleum ether, n-hexane and cyclohexane; (3) extracting the residue with an ethanol aqueous solution and centrifuging to obtain an extract; (4) concentrating the extract to obtain a concentrated solution, adding petroleum ether to the concentrated solution, cooling the solution to 0°C-5°C for 1.5-2.5 hours, filtering to remove impurities, and collecting liquid phase substances; (5) The liquid phase material is evaporated and crystallized, filtered, and dried to obtain fucoxanthin.

2. The preparation method according to claim 1, characterized in that: In step (2), during extraction, the mass volume ratio of the triangular phycodactylum powder to the non-polar solvent is 1: (4-5) g / mL; And / or, the temperature during extraction is 40° C. to 55° C., preferably the number of extractions is 2-4 times, and the time of each extraction is 0.8 to 1.5 hours.

3. The preparation method according to claim 1, characterized in that: In step (3), the concentration of the ethanol solution is 80-95% (v / v); and / or, the mass volume ratio of the raffinate to the ethanol solution is 1:(4-5) g / mL, And / or, the temperature during extraction is 40° C. to 55° C., preferably the number of extractions is 2-4 times, and the time of each extraction is 0.8 to 1.5 hours.

4. The preparation method according to claim 1, characterized in that: In step (4), the concentration is reduced pressure concentration, and the temperature of the reduced pressure concentration is 55° C. to 65° C., And / or, the vacuum degree of the reduced pressure concentration is -0.080Mpa to -0.095Mpa; and / or, the mass volume ratio of the Phaeodactylum triangularis powder to the concentrated solution is 1:(1-4) g / mL; And / or, the mass volume ratio of the Phaeodactylum triangularis powder to the petroleum ether is 1:(1-4) g / mL.

5. The preparation method according to claim 1, characterized in that: In step (5), the heating temperature of the evaporation crystallization is 50°C to 60°C, and / or the vacuum degree of the evaporation crystallization is -0.080Mpa to -0.095Mpa.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The preparation method further comprises a step (6), wherein the fucoxanthin obtained in step (5) is dissolved in an ethanol solution, slowly recrystallized by adding water, and filtered and dried to obtain crystalline fucoxanthin.

7. The preparation method according to claim 6, characterized in that: The concentration of the ethanol solution in step (6) is 95%-100% (v / v), and / or the mass volume ratio of the added amount of ethanol solution to fucoxanthin is 1:(40-70) g / mL.

8. The preparation method according to claim 6, characterized in that: In the step (6) of slowly adding water for recrystallization, the water is deionized water, and the amount of water added is such that the concentration of the ethanol solution is adjusted to 30-35% (v / v) after adding water.

9. Fucoxanthin prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the fucoxanthin according to claim 9 in food, health products, medicines, cosmetics and feed.

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