Lutein powder without antioxidant and method for preparing the same

Abstract

The present application discloses a lutein powder without antioxidant, which contains lutein and a stabilizer. The lutein powder has excellent stability. The powder is well dissolved in water, and no precipitation is observed in the saturated solution after long-term storage. In addition, the lutein powder can effectively prevent the oxidation of lutein in air without additional antioxidant. Furthermore, the lutein powder is easy to prepare and is very suitable for industrial production.

Description

Technical Field

[0001] This invention relates to a lutein powder, and more specifically to a lutein powder that is free of antioxidants and has excellent stability. This invention also relates to a method for preparing the lutein powder. Background Technology

[0002] Lutein is a natural substance with functions such as protecting eyesight, relieving eye fatigue, increasing macular pigment density, and preventing macular degeneration and retinitis pigmentosa. It has been applied in various fields including food, cosmetics, and medicine. However, lutein's poor water solubility leads to low bioavailability; furthermore, its unique conjugated polyene structure makes it extremely unstable and easily degraded, losing its activity. These drawbacks limit its applications.

[0003] CN102038644A discloses a water-soluble lutein powder and its preparation method. The powder includes lutein, carrier materials such as povidone, polyethylene glycol, mannose, galactose, and bile acids, and excipients such as polysorbate, sorbitol fatty acid esters, fatty acid sucrose esters, tocopherol, ascorbic acid, and tert-butylhydroxyphenyl methyl ether. The preparation method includes: mixing lutein with at least two of the carrier materials and excipients, adding an organic solvent and stirring to dissolve, evaporating to dryness under vacuum at a temperature of 30–85°C, and pulverizing. The entire preparation process is carried out under light-protected conditions. This powder has advantages such as good water solubility and good stability. However, this powder requires the use of antioxidants such as tocopherol and must be prepared under light-protected conditions.

[0004] CN101433528A discloses a stable, water-dispersible lutein microcapsule and its preparation method. The microcapsule contains lutein, vegetable oil, and emulsifiers such as soybean lecithin, phospholipids, Tween 80, sucrose esters, or 1,2-propanediol, as well as encapsulation materials such as soluble starch, sodium carboxymethyl cellulose, ethyl cellulose, and gelatin. The method involves dissolving lutein using a flash high-temperature melting method, adding emulsifiers, and then homogenizing under high pressure. The emulsion and encapsulation materials are then granulated in a fluidized bed to obtain the microcapsules. However, this microcapsule method requires the use of emulsifiers and high-pressure homogenization, which is not conducive to large-scale production.

[0005] There is still a need to provide better lutein products. Summary of the Invention

[0006] The purpose of this invention is to provide a stable, water-soluble lutein powder. This powder does not contain antioxidants, emulsifiers, or other additives, and can be prepared using a very simple industrial method. To achieve this objective, the technical solution adopted by this invention is as follows:

[0007] A lutein powder containing lutein and a stabilizer, said stabilizer being composed of sodium octenyl succinate starch and γ-cyclodextrin in a weight ratio of 3:1 to 1:3.

[0008] In some preferred embodiments, the weight ratio of sodium octenyl succinate starch and γ-cyclodextrin in the stabilizer is 1:3, 1:2, 1:1, 2:1 or 3:1.

[0009] Lutein is highly susceptible to oxidation. Existing technologies often employ the addition of antioxidants to prevent its deterioration, while others use encapsulation methods, but these methods often involve complex preparation processes. This invention unexpectedly discovered that a specific combination of sodium octenyl succinate starch and γ-cyclodextrin in a particular ratio can effectively maintain the stability of lutein. This combination acts as a co-stabilizer, capable of stabilizing both low and high concentrations of lutein.

[0010] In some preferred technical solutions, the weight ratio of lutein to stabilizer in the powder is 1:9 to 1:1000.

[0011] In some preferred technical solutions, the weight ratio of lutein to stabilizer in the powder is 1:9, 1:10, 1:20, 1:40, 1:80, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900 or 1:1000.

[0012] In some preferred technical solutions, the weight percentage of lutein in the powder is 0.1%-10%.

[0013] In some preferred technical solutions, the weight percentage of lutein in the powder is 0.1%, 0.25%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 9.09%, or 10%.

[0014] In some preferred embodiments, the lutein powder of the present invention does not contain antioxidants other than lutein, sodium octenyl succinate starch, and γ-cyclodextrin. Antioxidants are well known in the art, such as ascorbic acid, vitamin E, butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, and tert-butylhydroquinone.

[0015] In some preferred embodiments, the lutein powder of the present invention does not contain emulsifiers other than lutein, sodium octenyl succinate starch, and γ-cyclodextrin. Emulsifiers are well known in the art, such as Tween, Span, sodium lauryl sulfate, gelatin, phospholipids, etc.

[0016] The lutein powder of this invention can be used as a raw material or intermediate to prepare food, pharmaceuticals, functional beverages, etc., as needed, and other ingredients can be added. For example, flavoring agents can be added to improve the taste.

[0017] In some preferred technical solutions, lutein powder may optionally contain flavoring agents.

[0018] These flavoring agents can be commonly used flavoring agents in the food or pharmaceutical industries, such as sucrose and maltose. The weight percentage of the flavoring agent in the powder can be 0%-20%.

[0019] This invention also provides a method for preparing the above-mentioned lutein powder:

[0020] A method for preparing lutein powder includes the following steps:

[0021] (1) Dissolve lutein in an organic solvent to obtain solution a;

[0022] (2) Dissolve sodium octenyl succinate starch and γ-cyclodextrin, along with an optional flavoring agent, in water to obtain solution b;

[0023] (3) Mix solution a and solution b evenly, and spray dry the mixture to obtain lutein powder.

[0024] In this method, the weight ratio of sodium octenyl succinate starch and γ-cyclodextrin is 3:1 to 1:3.

[0025] In this method, the organic solvent is not particularly limited, as long as it can dissolve lutein, such as ethanol, ethyl acetate, etc.

[0026] In this method, the organic solvent added in step (1) and the water added in step (2) can be removed in the spray drying step (3).

[0027] The beneficial effects of this invention are:

[0028] The lutein powder of this invention exhibits excellent solubility and stability. The powder dissolves well in water, and no precipitation occurs even after prolonged standing of the saturated solution. Furthermore, the powder demonstrates excellent resistance to air oxidation, effectively preventing lutein from oxidizing and deteriorating in air without the need for additional antioxidants. Moreover, the lutein powder of this invention is simple to prepare, requiring only conventional mixing and spray drying methods, making it highly suitable for industrial production. Detailed Implementation

[0029] The present invention will be further illustrated below with examples, comparative examples, and experimental cases. It should be understood that the content of the detailed embodiments section is illustrative and not restrictive, that is, it does not limit the technical solution of the present invention in any way.

[0030] All raw and auxiliary materials used in the examples were commercially available.

[0031] Example 1

[0032] 0.1 kg of lutein was dissolved in 50 L of anhydrous ethanol to form a solution. 0.6 kg of sodium octenyl succinate starch and 0.3 kg of γ-cyclodextrin were dissolved in 40 L of purified water to form an aqueous solution. The ethanol solution and the aqueous solution were mixed and spray-dried to obtain lutein powder.

[0033] Example 2

[0034] Following the method in Example 1, 0.01 kg of lutein, 1 kg of sodium octenyl succinate starch, and 3 kg of γ-cyclodextrin were used to prepare lutein powder.

[0035] Example 3

[0036] Following the method of Example 1, 0.01 kg of lutein, 7.5 kg of sodium octenyl succinate starch, and 2.5 kg of γ-cyclodextrin were used to prepare lutein powder.

[0037] Example 4

[0038] Following the method of Example 1, 0.1 kg of lutein, 0.5 kg of sodium octenyl succinate starch, and 0.5 kg of γ-cyclodextrin were used to prepare lutein powder.

[0039] Example 5

[0040] 0.1 kg of lutein was dissolved in 30 L of anhydrous ethanol to form a solution. 4 kg of sodium octenyl succinate starch, 4 kg of γ-cyclodextrin, and 1.9 kg of maltose were dissolved in 50 L of purified water to form an aqueous solution. The ethanol solution and the aqueous solution were mixed and spray-dried to obtain lutein powder.

[0041] Comparative Example 1

[0042] Lutein powder was prepared by adjusting the ratio of sodium octenyl succinate starch and γ-cyclodextrin. 0.1 kg of lutein was dissolved in 50 L of anhydrous ethanol to form a solution, and 0.75 kg of sodium octenyl succinate starch and 0.15 kg of γ-cyclodextrin were dissolved in 40 L of purified water to form an aqueous solution. The ethanol solution and the aqueous solution were mixed thoroughly, and the mixture was spray-dried to obtain lutein powder.

[0043] Comparative Example 2

[0044] Lutein powder was prepared by adjusting the ratio of sodium octenyl succinate starch and γ-cyclodextrin. 0.1 kg of lutein was dissolved in 50 L of anhydrous ethanol to form a solution, and 0.15 kg of sodium octenyl succinate starch and 0.75 kg of γ-cyclodextrin were dissolved in 40 L of purified water to form an aqueous solution. The ethanol solution and the aqueous solution were mixed thoroughly, and the mixture was spray-dried to obtain lutein powder.

[0045] Comparative Example 3

[0046] Lutein powder was prepared by replacing sodium octenyl succinate starch with sodium carboxymethyl starch. 0.1 kg of lutein was dissolved in 50 L of anhydrous ethanol to form a solution, and 0.6 kg of sodium carboxymethyl starch and 0.3 kg of γ-cyclodextrin were dissolved in 40 L of purified water to form an aqueous solution. The ethanol solution and the aqueous solution were mixed thoroughly, and the mixture was spray-dried to obtain lutein powder.

[0047] Comparative Example 4

[0048] Lutein powder was prepared by replacing γ-cyclodextrin with β-cyclodextrin. 0.1 kg of lutein was dissolved in 50 L of anhydrous ethanol to form a solution. 0.6 kg of sodium octenyl succinate starch and 0.3 kg of β-cyclodextrin were dissolved in 40 L of purified water to form an aqueous solution. The ethanol solution and the aqueous solution were mixed thoroughly, and the mixture was spray-dried to obtain lutein powder.

[0049] Test Example 1: Solution Stability Test

[0050] Take 10g of lutein powder prepared in Examples 1-5 and Comparative Examples 1-4 respectively, add it to 100g of water, and stir in a water bath at 20℃ until the powder no longer dissolves, to obtain a saturated lutein solution. Take the supernatant and place it at room temperature, observing its properties at 0, 2, 4, 8, 24, and 48 hours after placement. The results are shown in Table 1.

[0051] Table 1. Properties of saturated solutions in each group after standing.

[0052]

[0053]

[0054] Comparative experiments show that the lutein powder of the present invention has good solubility in water, and the saturated solution did not become turbid or precipitate after long-term storage, indicating good stability.

[0055] In Comparative Examples 3 and 4, when the stabilizer was replaced with sodium carboxymethyl starch or β-cyclodextrin, trace precipitation appeared in the solution after 24 or 48 hours, indicating poor stability. This phenomenon shows that different types of starch derivatives and different types of cyclodextrin have a significant impact on the stability of lutein saturated solutions, and the type of stabilizer is crucial for maintaining the stability of lutein solutions.

[0056] Experimental Example 2: Antioxidant Stability Test

[0057] Lutein powders prepared in Examples 1-5 and Comparative Examples 1-4 were exposed to air at room temperature. Samples were taken at 0, 6, and 12 hours after exposure to determine the lutein content in the powder (UV-Vis spectrophotometry, wavelength 445 nm). The percentage decrease in content was calculated (the difference between the content at 12 hours and the content at 0 hours, divided by the content at 0 hours). The results are shown in Table 2.

[0058] Table 2. Changes in lutein content in each group of samples after exposure to air.

[0059] 0 hours 6 hours 12 hours Percentage change in content Example 1 9.990％ 9.973％ 9.951％ -0.390％ Example 2 0.246％ 0.244％ 0.244％ -0.813％ Example 3 0.100％ 0.099％ 0.099％ -1.000％ Example 4 9.082％ 9.060％ 9.040％ -0.462％ Example 5 0.997％ 0.994％ 0.992％ -0.502％ Comparative Example 1 9.990％ 9.782％ 9.402％ -5.886％ Comparative Example 2 9.992％ 9.681％ 9.583％ -4.093％ Comparative Example 3 9.998％ 9.390％ 9.110％ -8.882％ Comparative Example 4 9.996％ 9.403％ 9.281％ -7.153％

[0060] The results showed that after 12 hours of exposure to air, the lutein content in the samples of Comparative Example 1 and Comparative Example 2 decreased by more than 4%, and the lutein content in the samples of Comparative Example 3 and Comparative Example 4 decreased by more than 7%, indicating that a large amount of lutein was oxidized and deteriorated.

[0061] The lutein content in the lutein powder of this invention varies very little, remaining at 1% or less, exhibiting significantly better stability. This phenomenon indicates that the specific combination of sodium octenyl succinate starch and γ-cyclodextrin in this invention provides excellent protection for lutein.

[0062] The present invention has been described in detail above with general descriptions and specific embodiments. Based on this, those skilled in the art can make some changes or improvements. All such changes or improvements made without departing from the present invention are protected by the present invention.

Claims

1. A lutein powder containing lutein and a stabilizer, and optionally a flavoring agent; wherein the stabilizer is composed of sodium octenyl succinate starch and γ-cyclodextrin in a weight ratio of 3:1 to 1:3; wherein the lutein powder contains no antioxidants or emulsifiers other than lutein, sodium octenyl succinate starch and γ-cyclodextrin.

2. The lutein powder according to claim 1, wherein the weight ratio of lutein to stabilizer is 1:9 to 1:1000.

3. The lutein powder according to claim 1, wherein the weight percentage of lutein in the powder is 0.1%-10%.

4. The lutein powder according to claim 1, wherein the flavoring agent is selected from sucrose or maltose.

5. A method for preparing the lutein powder according to any one of claims 1-4, comprising the following steps: (1) Dissolve lutein in an organic solvent to obtain solution a; (2) Dissolve sodium octenyl succinate starch and γ-cyclodextrin, as well as optional flavoring agents in water to obtain solution b; (3) Mix solution a and solution b evenly, and spray dry the mixture to obtain lutein powder.

6. The preparation method according to claim 5, wherein the organic solvent is selected from ethanol and ethyl acetate.

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