CN114957072A - Method for preparing zeaxanthin and zeaxanthin pellet from marigold ointment - Google Patents

Abstract

The invention provides a method for preparing zeaxanthin from marigold ointment and a method for preparing zeaxanthin pellets. The specific steps include: adding an organic extractant to the marigold ointment, and treating it under ultrasonic conditions to obtain an extract; adding a phase transfer catalyst, a mixed alcohol and an alkaline solution to the extract, and heating with variable frequency stirring to carry out saponification reaction to obtain Saponification liquid; add emulsifier, co-catalyst and strong alkaline solution to the saponification liquid, stir under heating condition to carry out isomerization reaction to obtain zeaxanthin crude product; carry out desalination treatment to zeaxanthin crude product, and add acid Neutralize to obtain a filtrate; the filtrate is separated, filtered, washed and dried to obtain zeaxanthin. The method adopts the step-by-step reaction, and by adding a phase transfer catalyst, an emulsifier and a cocatalyst, the two-phase contact can be effectively increased, so as to improve the efficiency of the saponification reaction and the isomerization reaction, shorten the reaction time, and improve the conversion rate of zeaxanthin.

Description

Method for preparing zeaxanthin and zeaxanthin pellets from marigold ointment

technical field

The invention belongs to the technical field of carotenoid preparation, in particular to a method for preparing zeaxanthin from marigold ointment and a method for preparing zeaxanthin pellets.

Background technique

Carotenoids are a class of yellow to red substances that are widely found in nature. In general, carotenoids can be divided into two subclasses, lutein or oxygenated carotenoids with relatively strong polarity, such as Lutein, Zeaxanthin, Astaxanthin, etc. Both subclasses of carotenoids contain at least nine conjugated double bonds, which not only endow carotenoids with their color characteristics, but also have strong antioxidant functions in disease prevention and treatment. And because of the ability of carotenoids to clear high-efficiency reactive oxygen radicals and prevent the generation of free radicals, they can limit the oxidative damage of free radicals.

Lutein and zeaxanthin are isomers, the difference lies in the position of the double bond on one end ring, the position of the double bond on the two end rings of the former is symmetrical, and the latter is asymmetric, that is, the The entire straight-chain portion of each molecule of flavin and zeaxanthin is a conjugated structure with alternating double and single bonds, while in the zeaxanthin molecule, the conjugated structure continues to the first bond on the two end rings, The degree of conjugation is higher than that of lutein. In view of this feature, at present, the prior art mostly adopts the isomerization reaction to generate zeaxanthin under the catalysis of strong base, but the following shortcomings exist in the reaction under the condition that only strong base is used as a catalyst: one, the use of strong base The amount is relatively large, secondly, the reaction time is longer, and thirdly, the conversion rate is low, only 10%-20%.

Therefore, in view of the above problems, it is necessary to propose a new method for preparing zeaxanthin from marigold ointment.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a method for preparing zeaxanthin from marigold ointment and a method for preparing zeaxanthin pellets.

One aspect of the present invention provides a method for preparing zeaxanthin from marigold ointment, the specific steps comprising: adding an organic extractant to the marigold ointment, and processing under ultrasonic conditions to obtain an extract;

adding a phase transfer catalyst, mixed alcohol and an alkaline solution to the extract, heating and stirring with variable frequency to carry out a saponification reaction to obtain a saponification solution;

Adding emulsifier, cocatalyst and strong alkaline solution to the saponification solution, stirring under heating conditions to carry out isomerization reaction, to obtain zeaxanthin crude product;

The zeaxanthin crude product is desalted and neutralized with acid to obtain a filtrate;

The filtrate is separated, filtered, washed and dried to obtain the zeaxanthin.

Optionally, adding an organic extractant to the marigold ointment and processing under ultrasonic conditions to obtain an extract, including:

Add 0.5kg~3kg of organic extractant to 400g~600g of marigold ointment, and extract 100min~120min under the condition that ultrasonic power range is 300W~600W and temperature range is 50°C~60°C to obtain an extract.

Optionally, adding a phase transfer catalyst, mixed alcohol and an alkaline solution to the extraction solution, heating with variable frequency stirring to carry out a saponification reaction, to obtain a saponification solution, including:

Add 10g~30g phase transfer catalyst and 400g~600g mixed alcohol to the extract, and under the condition that the heating temperature range is 90°C~110°C, add 50g~150g of alkaline solution dropwise, and stir in the range of rotation speed. Frequency conversion stirring is carried out for 25r/min~50r/min, and the saponification reaction is carried out for 1h~3h to obtain the saponification liquid.

Optionally, the phase transfer catalyst adopts benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, ten any one of dialkyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, and an onium salt; and/or,

The mixed alcohol adopts at least one of methanol, ethanol, isopropanol and n-butanol; and/or,

The alkali solution adopts sodium hydroxide aqueous solution or potassium hydroxide aqueous solution.

Optionally, adding an emulsifier, a cocatalyst and a strong alkaline solution to the saponification solution, and stirring under heating conditions to carry out an isomerization reaction to obtain a zeaxanthin crude product, including:

Add 50g~100g of emulsifier and 20g~120g of co-catalyst to the saponification solution, and under the condition that the temperature range is 85°C~100°C, dropwise add 20g~100g of strong alkaline solution to the stirring speed range Stirring at 20r/min~40r/min, isomerization reaction for 5h~8h, to obtain the crude product of zeaxanthin.

Optionally, the emulsifier adopts Tween series or Span series; and/or,

The co-catalyst adopts any one of a metal salt catalyst, an N-doped carbon dioxide catalyst, a gold/silver co-doped nano-catalyst, and a carbon-doped palladium catalyst; and/or,

The strong alkaline solution adopts any one of tert-butyl sodium, sodium methoxide, sodium ethoxide and sodium dimethyl sulfoxide.

Optionally, the described zeaxanthin crude product is desalted and neutralized with acid to obtain a filtrate, including:

Under stirring conditions, add 400g~600g of ethanol and 1L~3L of pure water at 60°C to 70°C to the zeaxanthin crude product for dilution and desalination treatment; after that, slowly add acid solution, and keep the temperature range at 65 °C ℃~70℃, stir until the pH range of the solution is 8~9, and let stand for 12h~16h to obtain the filtrate.

Optionally, the described filtrate is separated, filtered, washed and dried to obtain the zeaxanthin, including:

The filtrate is separated and filtered by a plate and frame filter press, wherein the plate and frame system is preheated to 70°C to 75°C with purified water, and the temperature is maintained at 70°C to 72°C to filter the filtrate. treatment; after that, use pure water at 60°C to 70°C to elute to neutrality to obtain a filter cake;

The filter cake is dried in a vacuum drying oven with a vacuum degree ranging from -0.06Mpa to -0.08Mpa and a temperature ranging from 42°C to 45°C for 8h to 10h to obtain the zeaxanthin.

Another aspect of the present invention provides a kind of preparation method of zeaxanthin pellet, the concrete steps include:

Add maltodextrin, microcrystalline cellulose and antioxidants to zeaxanthin and mix well;

A wetting agent is added to the uniformly mixed material for mixing and granulation, and dried in a vacuum drying oven with a temperature range of 42°C to 45°C for 8h to 10h to obtain the zeaxanthin pellets; wherein, the corn Xanthin is prepared by the method described in any one of claims 1 to 8.

Optionally, the wetting agent is 30% ethanol, and the amount of the wetting agent is 0.8 to 1.5 times that of the zeaxanthin.

The invention provides a method for preparing zeaxanthin from marigold ointment. The specific steps include: adding an organic extractant to the marigold ointment, and processing under ultrasonic conditions to obtain an extract; adding an organic extractant to the extract; Phase transfer catalyst, mixed alcohol and alkaline solution are heated with variable frequency stirring to carry out saponification reaction to obtain saponification liquid; emulsifier, co-catalyst and strong alkaline solution are added to the saponification liquid, and isomerization reaction is carried out with stirring under heating conditions, to obtain a zeaxanthin crude product; carry out desalination treatment to the zeaxanthin crude product, and add acid to neutralize to obtain a filtrate; separate, filter, wash and dry the filtrate to obtain the zeaxanthin . The method adopts step-by-step reaction, that is, the saponification reaction is carried out first, and a phase transfer catalyst is added in the process of the saponification reaction, so as to utilize its own affinity for the organic solvent, which can effectively increase the contact between the two phases, promote the reaction to occur, and improve the saponification. reaction efficiency. Secondly, emulsifiers and co-catalysts are added in the isomerization reaction process, so that the carotenoids can be dissolved better, and at the same time, the efficiency of the isomerization reaction is improved, the amount of strong alkali used is reduced, the reaction time is shortened, and the corn The conversion rate of xanthan.

Description of drawings

1 is a flowchart of a method for preparing zeaxanthin from marigold ointment according to an embodiment of the present invention; FIG. 2 is a flowchart of a method for preparing zeaxanthin pellets according to an embodiment of the present invention.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in Figure 1, one aspect of the present invention provides a method S100 for preparing zeaxanthin from marigold ointment, which specifically includes the following steps S110~S150:

S110, adding an organic extractant to the marigold ointment, and processing under ultrasonic conditions to obtain an extract.

Specifically, adding 0.5kg-3kg of organic extractant to 400g-600g of marigold ointment, and extracting 100min-120min under the conditions that the ultrasonic power range is 300W-600W and the temperature range is 50°C-60°C, to obtain extraction liquid.

In this example, marigold ointment is pretreated under ultrasonic conditions, so that it can be fully dissolved. It should be understood that the fully dissolved marigold ointment solution contains lutein ester, therefore, it is necessary to use an organic extractant to extract the lutein ester to obtain the extract. Wherein, the organic extractant can be selected from at least one of n-hexane, ethyl acetate, propyl acetate, isopropanol, methanol and ethanol, and organic solvents such as petroleum ether, acetone and tetrahydrofuran which are more toxic are not used.

S120, adding a phase transfer catalyst, a mixed alcohol and an alkaline solution to the extract, and heating with variable frequency stirring to carry out a saponification reaction to obtain a saponification solution.

Specifically, 10g-30g of phase transfer catalyst and 400g-600g of mixed alcohol are added to the extract obtained in step S110, and 50g-150g of alkaline solution is added dropwise under the condition that the heating temperature range is 90°C-110°C, And the stirring speed range is 25r/min~50r/min to carry out variable frequency stirring, and the saponification reaction is carried out for 1h~3h, so as to obtain the saponified liquid.

It should be noted that the current conventional saponification reaction process is to directly add the alkali solution to the ester solution, or add some ethanol and the alkali solution to directly carry out the saponification reaction, which will cause problems such as insufficient reaction and low yield. In order to solve this problem, in this example, the extraction solution was first stirred at a stirring speed of 35 r/min, and then a phase transfer catalyst and mixed alcohol were added. Stirring at a stirring speed of 45 r/min is conducive to the sufficient reaction between the alkali solution and the ester. Moreover, it is not difficult to understand that the saponification reaction of this embodiment can be carried out in a saponification tank, and the saponification reaction can be made more sufficient by step-by-step variable frequency stirring, further improving the yield and shortening the reaction time.

It should be further noted that, based on the present embodiment, it is necessary to add an alkaline solution and an ester to carry out a saponification reaction, and the alkaline solution belongs to an aqueous solution, and the ester belongs to an organic solvent, and the two phases are isolated from each other, and the reactants cannot be effectively contacted. Based on this, the inventors After many experiments, it was found that the synergistic addition of mixed alcohol and phase transfer catalyst into the reaction system can effectively increase the contact between the two phases and promote the reaction by utilizing its own affinity for organic solvents.

Specifically, the phase transfer catalyst of this embodiment can be benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride , any one of dodecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium chloride and onium salts.

It should still be noted that, the mixed alcohol in this embodiment can be at least one of methanol, ethanol, isopropanol, and n-butanol. And, the alkali solution of this embodiment adopts sodium hydroxide aqueous solution or potassium hydroxide aqueous solution.

S130, adding an emulsifier, a co-catalyst and a strong alkaline solution to the saponification solution, and stirring the isomerization reaction under heating conditions to obtain a crude product of zeaxanthin.

Specifically, 50g~100g of emulsifier and 20g~120g of co-catalyst are added to the saponification solution, and 20g~100g of strong alkaline solution is added dropwise under the condition that the temperature range is 85°C~100°C, to The stirring speed range is 20r/min~40r/min, and the isomerization reaction is carried out for 5h~8h to obtain the crude product of zeaxanthin.

In this embodiment, by adding an emulsifier, the carotenoid can be dissolved better, and the solubility of the free carotenoid in the carotenoid can be increased, which can effectively increase the contact between the strong alkaline solution and the reaction substrate, and make the reaction more thorough. Also, a co-catalyst is added at the same time to promote the isomerization reaction. Under this condition, adding a strong alkaline solution dropwise is conducive to the conversion of lutein to zeaxanthin, improves the conversion rate, and reduces the amount of strong alkali used. Compared with the current isomerization reaction of dozens of hours, it can effectively shorten the time for the isomerization reaction.

Optionally, the emulsifier in this embodiment adopts Tween series or Span series, for example, Tween-60, Tween-80, Span-60 and the like. And, the co-catalyst can be any one of metal salt catalyst, N-doped carbon dioxide catalyst, gold/silver co-doped nano-catalyst and carbon-doped palladium catalyst. And, any one of tert-butyl sodium, sodium methoxide, sodium ethoxide and sodium dimethyl sulfoxide is used as the strong alkaline solution.

S140, performing desalination treatment on the crude zeaxanthin product, and adding acid for neutralization to obtain a filtrate.

Specifically, under stirring conditions, 400g-600g of ethanol and 1L-3L of pure water at 60°C to 70°C are added to the zeaxanthin crude product for dilution and desalination treatment; after that, an acid solution is slowly added, and the temperature is maintained. The range is 65℃~70℃, stir until the pH of the solution is in the range of 8~9, and let stand for 12h~16h to obtain the filtrate. Of course, the above process can be left for 3min~7min after the pH value is detected, and the pH value can be re-measured again until the value is in the range of 8~9, and the stirring is stopped.

The acid solution is not specifically limited in this embodiment, and an organic acid or an inorganic acid may be used, for example, formic acid, oxalic acid, benzenesulfonic acid, perchloric acid, phosphoric acid, and the like. Specifically, for the preparation of the acid solution, the following process can be used: 250-350 g of acid is mixed with 250-350 mL of pure water.

S150, performing separation filtration, washing and drying on the filtrate to obtain the zeaxanthin.

Specifically, in this embodiment, a plate-and-frame filter press is used to separate and filter the filtrate, wherein the plate-and-frame system is preheated with purified water to 70°C to 75°C, and the temperature is maintained at 70°C to 72°C. The filtrate is subjected to pressure filtration, and the zeaxanthin wet product is obtained by separation. After that, it is eluted to neutrality with pure water at 60°C to 70°C to obtain a filter cake. The filter cake is then dried in a vacuum drying oven with a vacuum degree ranging from -0.06Mpa to -0.08Mpa and a temperature ranging from 42°C to 45°C for 8h to 10h to obtain the zeaxanthin.

As shown in Figure 2, another aspect of the present invention provides a preparation method S200 of zeaxanthin pellets, which specifically includes the following steps S210-S220:

S210, adding maltodextrin, microcrystalline cellulose and antioxidant to zeaxanthin and mixing uniformly.

It should be noted that the antioxidant in this embodiment can be any one of tocopherol, tea polyphenol, bamboo leaf extract, butylated hydroxyanisole and dibutylated hydroxytoluene.

S220, adding a wetting agent to the uniformly mixed material for mixing and granulating, and drying it in a vacuum drying oven with a temperature range of 42°C to 45°C for 8h to 10h to obtain the zeaxanthin pellets; wherein the zeaxanthin pellets are obtained. The zeaxanthin of the step is prepared by the method described above, and the specific preparation method will not be repeated.

It should be noted that the wetting agent in this embodiment adopts 30% ethanol, and the dosage of the wetting agent is 0.8 times to 1.5 times that of the zeaxanthin.

It should be further noted that, the granulation method of this embodiment may adopt methods such as extrusion spheronization method, powder layer deposition method, and compression method.

The method for preparing zeaxanthin by marigold ointment and the method for preparing zeaxanthin pellets will be further described below in conjunction with several specific embodiments:

Example 1

The method for preparing zeaxanthin from marigold ointment in this example includes the following steps:

S1, add the organic extractant that 1kg of ethyl acetate and ethanol are mixed in the marigold ointment of 500g, extract 110min under the condition that ultrasonic power is 450W, temperature is 55 ℃, to obtain extract.

S2, the extraction solution obtained in step S1 is stirred at a stirring speed of 35 r/min, and 10 g of a tetrabutylammonium chloride phase transfer catalyst and a mixed alcohol of 500 g of methanol and ethanol are added, and the heating temperature is 95 ℃. Then, 100 g of sodium hydroxide alkali solution was added dropwise, and stirred at a stirring speed of 45 r/min, and the saponification reaction was carried out for 2 hours to obtain a saponified solution.

S3, the saponification solution obtained in step S2 is added to the metal salt catalyst of 80g of Tween-80 and 70g, and under the condition that the temperature is 90 ° C, 60g of strong alkaline solution is added dropwise, and the stirring speed is 35r/min to carry out Stir, isomerization reaction 6h, to obtain zeaxanthin crude product.

S4. Under stirring conditions, add 500 g of ethanol and 2 L of pure water at 65°C to the zeaxanthin crude product for dilution and desalination treatment; after that, slowly add an acid solution, keep the temperature at 65°C, and stir until the pH of the solution is 8 , let stand for 12h to obtain filtrate.

S5. Use a plate and frame filter press to separate and filter the filtrate, wherein the plate and frame system is preheated to 70° C. with purified water, and the temperature is maintained at 70° C. The filtrate is subjected to pressure filtration treatment, and the obtained Zeaxanthin wet product. After that, it was eluted to neutrality with pure water at 65°C to obtain a filter cake. The filter cake was then dried in a vacuum drying oven with a vacuum degree of -0.06Mpa and a temperature of 42°C for 8h to obtain 38.5g of zeaxanthin.

The determination shows that the content of zeaxanthin prepared in this example is 62.5%.

In this embodiment, the prepared zeaxanthin is further prepared to form zeaxanthin pellets, and the specific steps include:

S1. Add 100 g of maltodextrin, 8 g of microcrystalline cellulose and tocopherol to 20 g of zeaxanthin and mix evenly.

S2. Add 30% ethanol to the uniformly mixed material for mixing and granulation, and dry in a vacuum drying oven at a temperature of 43° C. for 8 hours to obtain zeaxanthin pellets.

Example 2

The method for preparing zeaxanthin from marigold ointment in this example includes the following steps:

S1, add 1kg of n-hexane and methanol mixed organic extractant in 500g of marigold ointment, extract 110min under the condition that ultrasonic power is 450W, temperature is 55 ℃, to obtain extract.

S2, the extraction solution obtained in step S1 is stirred at a stirring speed of 35 r/min, and 20 g of trioctyl methyl ammonium chloride phase transfer catalyst and 500 g of mixed alcohol of methanol and ethanol are added, and the heating temperature is 95 ° C Under the condition of , 120 g of sodium hydroxide alkali solution was added dropwise, and stirred at a stirring speed of 45 r/min, and the saponification reaction was carried out for 2 h to obtain a saponified solution.

S3, the saponification solution obtained in step S2 is added to the metal salt catalyst of 80g of Tween-60 and 70g, and under the condition that the temperature is 90°C, 60g of strong alkaline solution is added dropwise, and the stirring speed is 35r/min to carry out Stir, isomerization reaction 6h, to obtain zeaxanthin crude product.

S4. Under stirring conditions, add 500 g of ethanol and 2 L of pure water at 65°C to the zeaxanthin crude product for dilution and desalination treatment; after that, slowly add an acid solution, keep the temperature at 65°C, and stir until the pH of the solution is 8 , let stand for 12h to obtain filtrate.

S5. Use a plate and frame filter press to separate and filter the filtrate, wherein the plate and frame system is preheated to 70° C. with purified water, and the temperature is maintained at 70° C. The filtrate is subjected to pressure filtration treatment, and the obtained Zeaxanthin wet product. After that, it was eluted to neutrality with pure water at 65°C to obtain a filter cake. The filter cake was then dried in a vacuum drying oven with a vacuum degree of -0.06Mpa and a temperature of 42°C for 8h to obtain 39.7g of zeaxanthin.

The determination shows that the content of zeaxanthin prepared in this example is 65.1%. It can be seen that increasing the amount of phase transfer catalyst and the amount of sodium hydroxide alkali solution in step S2 can promote the saponification reaction to obtain more zeaxanthin.

In this embodiment, the prepared zeaxanthin is further prepared to form zeaxanthin pellets, and the specific steps include:

S1. Add 90 g of maltodextrin, 10 g of microcrystalline cellulose and tocopherol to 20 g of zeaxanthin and mix evenly.

S2. Add 30% ethanol to the uniformly mixed material for mixing and granulation, and dry in a vacuum drying oven at a temperature of 43° C. for 8 hours to obtain zeaxanthin pellets.

Example 3

The method for preparing zeaxanthin from marigold ointment in this example includes the following steps:

S1, add the organic extractant that 1kg of propyl acetate and ethanol are mixed in the marigold ointment of 500g, extract 110min under the condition that ultrasonic power is 450W, temperature is 55 ℃, to obtain extract.

S2, the extraction solution obtained in step S1 is stirred at a stirring speed of 35 r/min, and the mixed alcohol of 20 g of dodecyl trimethyl ammonium chloride phase transfer catalyst and 500 g of methanol and ethanol is added, and the heating temperature is Under the condition of 100°C, 120 g of sodium hydroxide alkali solution was added dropwise, and stirred at a stirring speed of 45 r/min, and the saponification reaction was carried out for 2 hours to obtain a saponified solution.

S3, adding 100 g of Tween-60 and 100 g of gold/silver co-doped nano-catalyst to the saponification solution obtained in step S2, and adding 80 g of strong alkaline solution dropwise at a temperature of 90° C. to stir The rotating speed is 35r/min for stirring, and the isomerization reaction is carried out for 6h to obtain the crude product of zeaxanthin.

S4. Under stirring conditions, add 500 g of ethanol and 2 L of pure water at 65°C to the zeaxanthin crude product for dilution and desalination treatment; after that, slowly add an acid solution, keep the temperature at 65°C, and stir until the pH of the solution is 8 , let stand for 12h to obtain filtrate.

S5. Use a plate and frame filter press to separate and filter the filtrate, wherein the plate and frame system is preheated to 70° C. with purified water, and the temperature is maintained at 70° C. The filtrate is subjected to pressure filtration treatment, and the obtained Zeaxanthin wet product. After that, it was eluted to neutrality with pure water at 65°C to obtain a filter cake. The filter cake was then dried in a vacuum drying oven with a vacuum degree of -0.06Mpa and a temperature of 42°C for 8 hours to obtain 41.5g of zeaxanthin.

The determination shows that the content of zeaxanthin prepared in this example is 70.0%. It can be seen that appropriately increasing the content of emulsifier, catalyst and strong alkali solution in step S3 can effectively promote the isomerization reaction, so as to increase the content of zeaxanthin in the product.

In this embodiment, the prepared zeaxanthin is further prepared to form zeaxanthin pellets, and the specific steps include:

S1. Add 110g maltodextrin, 12g microcrystalline cellulose and tocopherol to 20g zeaxanthin and mix well.

S2. Add 30% ethanol to the uniformly mixed material for mixing and granulation, and dry in a vacuum drying oven at a temperature of 43° C. for 8 hours to obtain zeaxanthin pellets.

Comparative Example 1

The method for preparing zeaxanthin from marigold ointment in this example includes the following steps:

S1, add the organic extractant that 1kg of ethyl acetate and ethanol are mixed in the marigold ointment of 500g, extract 110min under the condition that ultrasonic power is 450W, temperature is 55 ℃, to obtain extract.

S2, stirring the extraction solution obtained in step S1 at a stirring speed of 35 r/min, adding 500 g of mixed alcohol of methanol and ethanol, and adding 120 g of sodium hydroxide alkali solution dropwise under the condition that the heating temperature is 100 ° C, and Stir at a stirring speed of 45 r/min, and carry out the saponification reaction for 2 hours to obtain a saponified solution.

S3, the saponification solution obtained in step S2 is added to the metal salt catalyst of 80g of Tween-60 and 70g, and under the condition that the temperature is 90°C, 60g of strong alkaline solution is added dropwise, and the stirring speed is 35r/min to carry out Stir, isomerization reaction 6h, to obtain zeaxanthin crude product.

S4. Under stirring conditions, add 500 g of ethanol and 2 L of pure water at 65°C to the zeaxanthin crude product for dilution and desalination treatment; after that, slowly add an acid solution, keep the temperature at 65°C, and stir until the pH of the solution is 8 , let stand for 12h to obtain filtrate.

S5. Use a plate and frame filter press to separate and filter the filtrate, wherein the plate and frame system is preheated to 70° C. with purified water, and the temperature is maintained at 70° C. The filtrate is subjected to pressure filtration treatment, and the obtained Zeaxanthin wet product. After that, it was eluted to neutrality with pure water at 65°C to obtain a filter cake. The filter cake was then dried in a vacuum drying oven with a vacuum degree of -0.06Mpa and a temperature of 42°C for 8h to obtain 23.7g of zeaxanthin.

The determination shows that the content of zeaxanthin prepared in this example is 43.1%. Compared with the above examples, it can be concluded that in step S2, the addition of the phase transfer catalyst is removed, and alcohol and alkali are directly added to carry out saponification reaction, and the content of zeaxanthin obtained therefrom is significantly reduced.

Comparative Example 2

The method for preparing zeaxanthin from marigold ointment in this example includes the following steps:

S1, add 500g of ethyl acetate and ethanol mixed organic extractant to 500g of marigold ointment, and extract for 110min under the condition that ultrasonic power is 450W and temperature is 55°C to obtain an extract.

S2, the extraction solution obtained in step S1 is stirred at a stirring speed of 35 r/min, and 10 g of tetrabutylammonium chloride phase transfer catalyst and 500 g of mixed alcohol of methanol and ethanol are added, and the heating temperature is 100 ℃. , 100g of sodium hydroxide alkaline solution was added dropwise, and the stirring speed was 45r/min, and the saponification reaction was carried out for 2h to obtain a saponified solution.

S3, under the condition that the temperature of the saponification solution obtained in step S2 is 90 ° C, dropwise add 60 g of strong alkaline solution, stir with a stirring speed of 35 r/min, and perform isomerization reaction for 6 h to obtain a zeaxanthin crude product .

S4. Under stirring conditions, add 500 g of ethanol and 2 L of pure water at 65°C to the zeaxanthin crude product for dilution and desalination treatment; after that, slowly add an acid solution, keep the temperature at 65°C, and stir until the pH of the solution is 8 , let stand for 12h to obtain filtrate.

S5. Use a plate and frame filter press to separate and filter the filtrate, wherein the plate and frame system is preheated to 70° C. with purified water, and the temperature is maintained at 70° C. The filtrate is subjected to pressure filtration treatment, and the obtained Zeaxanthin wet product. After that, it was eluted to neutrality with pure water at 65°C to obtain a filter cake. The filter cake was then dried in a vacuum drying oven with a vacuum degree of -0.06Mpa and a temperature of 42°C for 8h to obtain 16.9g of zeaxanthin.

The determination shows that the content of zeaxanthin prepared in this example is 35.6%. Compared with the above-mentioned embodiments, it can be concluded that in step S3, the emulsifier and the cocatalyst are removed, and the alkali is directly added to carry out the isomerization reaction, and it only obtains 35.6% zeaxanthin, which shows that a large amount of leaf in the product is obtained. Flavin did not undergo isomerization.

Comparative Example 3

The method for preparing zeaxanthin from marigold ointment in this example includes the following steps:

S1, add the organic extractant that 1kg of ethyl acetate and ethanol are mixed in the marigold ointment of 500g, extract 110min under the condition that ultrasonic power is 450W, temperature is 55 ℃, to obtain extract.

S2, the extraction solution obtained in step S1 is stirred at a stirring speed of 35 r/min, and 10 g of tetrabutylammonium chloride phase transfer catalyst and 500 g of mixed alcohol of methanol and ethanol are added, and the heating temperature is 100 ℃. , 100 g of sodium hydroxide alkali solution was added dropwise, and stirred at a stirring speed of 45 r/min to obtain a crude product of zeaxanthin.

S3, under stirring condition, add the ethanol of 500g, the pure water 2L of 65 ℃ in the zeaxanthin crude product to carry out the dilution desalting treatment; After that, slowly add the acid solution, and keep the temperature at 65 ℃, stir until the pH of the solution is 8 , let stand for 12h to obtain filtrate.

S4. Use a plate and frame filter press to separate and filter the filtrate, wherein the plate and frame system is preheated to 70° C. with purified water, and the temperature is kept at 70° C. The filtrate is subjected to pressure filtration treatment, and the obtained Zeaxanthin wet product. After that, it was eluted to neutrality with pure water at 65°C to obtain a filter cake. The filter cake was then dried in a vacuum drying oven with a vacuum degree of -0.06Mpa and a temperature of 42°C for 8h to obtain 11.3g of zeaxanthin.

The determination shows that the content of zeaxanthin prepared in this example is 19.2%. Compared with the above-mentioned embodiments, it can be concluded that steps S2 and S3 are combined together, and an alkaline solution is added to carry out saponification and isomerization reaction. The isomerization reaction effect is worse, and only 19.2% of zeaxanthin is obtained. It is illustrated that the above-mentioned embodiment adopts the step-by-step process to enable the reaction to proceed sufficiently and has a relatively high conversion rate.

The present invention provides a method for preparing zeaxanthin from marigold ointment and a method for preparing zeaxanthin pellets. Compared with the prior art, the present invention has the following beneficial effects: the present invention adopts a step-by-step reaction, that is, saponification is performed first. In the process of saponification reaction, a phase transfer catalyst is added to utilize its affinity for organic solvents, which can effectively increase the contact between the two phases, promote the reaction, and improve the efficiency of the saponification reaction. Secondly, emulsifiers and co-catalysts are added in the isomerization reaction process, so that the carotenoids can be dissolved better, and at the same time, the efficiency of the isomerization reaction is improved, the amount of strong alkali used is reduced, the reaction time is shortened, and the corn The conversion rate of xanthan.

It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, without departing from the spirit and essence of the present invention, various modifications and improvements can be made, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (10)

1. A method for preparing zeaxanthin from marigold ointment is characterized by comprising the following specific steps: adding organic extractant into marigold ointment, and treating under ultrasonic condition to obtain extractive solution;

adding a phase transfer catalyst, mixed alcohol and an alkali solution into the extracting solution, heating, carrying out variable frequency stirring, and carrying out saponification reaction to obtain a saponified solution;

adding an emulsifier, a cocatalyst and a strong alkaline solution into the saponification solution, and stirring under a heating condition for an isomerization reaction to obtain a zeaxanthin crude product;

desalting the zeaxanthin crude product, and adding acid for neutralization to obtain a filtrate;

and separating, filtering, washing and drying the filtrate to obtain the zeaxanthin.

2. The method of claim 1, wherein the marigold ointment is treated with an organic extractant under sonication conditions to obtain an extract solution comprising:

adding 0.5 kg-3 kg of organic extractant into 400 g-600 g of marigold ointment, and extracting for 100 min-120 min under the conditions that the ultrasonic power range is 300W-600W and the temperature range is 50-60 ℃ to obtain an extracting solution.

3. The method of claim 1, wherein adding a phase transfer catalyst, a mixed alcohol and an alkali solution to the extract, heating and stirring with variable frequency to perform saponification reaction to obtain a saponified solution, comprising:

adding 10 g-30 g of phase transfer catalyst and 400 g-600 g of mixed alcohol into the extracting solution, dropwise adding 50 g-150 g of alkali solution under the condition that the heating temperature is 90-110 ℃, carrying out variable frequency stirring at the stirring speed of 25 r/min-50 r/min, and carrying out saponification reaction for 1-3 h to obtain a saponified solution.

4. The method according to claim 3, wherein the phase transfer catalyst is any one of benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, and onium salts; and/or the presence of a gas in the gas,

the mixed alcohol is at least one of methanol, ethanol, isopropanol and n-butanol; and/or the presence of a gas in the atmosphere,

the alkali solution adopts sodium hydroxide aqueous solution or potassium hydroxide aqueous solution.

5. The method of claim 1, wherein the step of adding an emulsifier, a cocatalyst and a strongly alkaline solution to the saponified solution and stirring under heating for isomerization reaction to obtain a crude zeaxanthin product comprises:

adding 50 g-100 g of emulsifier and 20 g-120 g of cocatalyst into the saponification solution, dropwise adding 20 g-100 g of strong alkaline solution at the temperature of 85-100 ℃, stirring at the stirring speed of 20 r/min-40 r/min, and carrying out isomerization reaction for 5-8 h to obtain a zeaxanthin crude product.

6. The method according to claim 5, wherein the emulsifier is tween series or span series; and/or the presence of a gas in the gas,

the cocatalyst adopts any one of a metal salt catalyst, an N-doped carbon dioxide catalyst, a gold/silver co-doped nano catalyst and a carbon-doped palladium catalyst; and/or the presence of a gas in the gas,

the strong alkaline solution adopts any one of tert-butyl sodium, sodium methoxide, sodium ethoxide and sodium dimethyl sulfoxide.

7. The method of claim 1, wherein the desalting of the zeaxanthin crude product and the neutralization with acid to obtain a filtrate comprises:

under the condition of stirring, adding 400-600 g of ethanol and 1-3L of pure water at 60-70 ℃ into the zeaxanthin crude product to dilute and desalt; and slowly adding an acid solution, keeping the temperature within the range of 65-70 ℃, stirring until the pH value of the solution is within the range of 8-9, and standing for 12-16 hours to obtain a filtrate.

8. The method as claimed in claim 1, wherein the separating, filtering, washing and drying the filtrate to obtain the zeaxanthin comprises:

separating and filtering the filtrate by adopting a plate-and-frame filter press, wherein a plate-and-frame system is preheated to 70-75 ℃ by adding purified water, and the filtrate is subjected to filter pressing treatment under the condition that the temperature is kept at 70-72 ℃; then, eluting the mixture to be neutral by pure water at the temperature of 60-70 ℃ to obtain a filter cake;

and (3) putting the filter cake into a vacuum drying oven with the vacuum degree range of-0.06 Mpa to-0.08 Mpa and the temperature range of 42 ℃ to 45 ℃ for drying for 8h to 10h to obtain the zeaxanthin.

9. A preparation method of zeaxanthin pellets is characterized by comprising the following specific steps:

adding maltodextrin, microcrystalline cellulose and antioxidant into zeaxanthin, and mixing;

adding a wetting agent into the uniformly mixed materials for mixing and granulating, and drying for 8-10 h in a vacuum drying oven at the temperature of 42-45 ℃ to obtain the zeaxanthin pellets; wherein the zeaxanthin is prepared by the method of any one of claims 1 to 8.

10. The method of claim 9, wherein 30% ethanol is used as the wetting agent, and the amount of the wetting agent is 0.8 to 1.5 times that of the zeaxanthin.

Images