A preparation method of Maillard polyunsaturated fatty acid oil microcapsules

Abstract

The present invention provides a method for preparing Maillard polyunsaturated fatty acid oil microcapsules. The method for preparing the polyunsaturated fatty acid oil microcapsules comprises the following steps: (1) dissolving sodium caseinate, glucose and lactose in water and mixing them evenly, adding a moisture retaining agent, adjusting the Maillard reaction pH to 8-10, and obtaining an aqueous phase after the reaction; (2) adding polyunsaturated fatty acid oil to the aqueous phase and emulsifying by shearing; (3) adding cellulose and its derivatives to the system obtained in step (2), and shearing to obtain an emulsion; the content of polyunsaturated fatty acid oil in the polyunsaturated fatty acid oil microcapsules is not less than 40wt%. The preparation method provided by the present invention can improve the rehydration property of the Maillard microcapsule product with high oil content, while ensuring that the product is not over-dried, improving the product sensory properties, and ensuring its sensory stability during the shelf life.

Description

Technical Field

[0001] The present invention relates to the field of preparation of polyunsaturated fatty acids, and more particularly to a method for preparing Maillard polyunsaturated fatty acid oil microcapsules. Background Art

[0002] Polyunsaturated fatty acid oils, such as arachidonic acid oil and docosahexaenoic acid oil, are susceptible to oxidation due to their structure, producing unpleasant odors and affecting their functionality. Microencapsulation technology is often used to protect polyunsaturated fatty acid oils such as arachidonic acid oil and docosahexaenoic acid oil using encapsulation materials to improve their stability and flavor. During the preparation process of high-oil-loaded polyunsaturated fatty acid oil microcapsules, the hydrophobic oil accounts for 50% or more of the system, which is significantly different from the systems established for existing conventional polyunsaturated fatty acid products. The aqueous phase in the emulsion system tends to migrate to the surface, making it prone to rapid water loss during the drying process. This can lead to over-drying of the product, which not only affects the sensory perception of the product but can even cause discoloration during the shelf life, impacting back-end applications.

[0003] In the process of seeking a solution to the stability of high-content polyunsaturated fatty acid microcapsules, the applicant paid attention to the Maillard reaction products. Maillard reaction products have high thermal stability and oxidative stability. Whey protein, sodium caseinate, soy protein isolate, amino acids, and other proteins and sugars such as glucose, lactose, and oligomaltodextrose are all commonly used raw materials for preparing Maillard products. For example, "Preparation of Maillard Reaction Products and Their Application in Mixed Oil Microcapsules" discloses that the Maillard reaction products of sodium caseinate and oligomaltodextrose are used as wall materials to embed mixed oils. CN105685770A discloses the use of whey protein, casein, amino acids, lactose, and monosaccharides to prepare Maillard reaction products for embedding oils.

[0004] Although it is generally believed in the prior art that covalent complexes of proteins and sugars have good solubility, in fact, during the application process of the present applicant, it was found that the oil microcapsule product obtained by encapsulating the Maillard reaction product constructed by using a sodium caseinate-glucose and lactose complex carbohydrate system performed poorly in the dissolution dispersion experiment. In addition, during the preparation process of polyunsaturated fatty acid oil microcapsules with high oil loading rate, since the hydrophobic oil accounts for 50% or more in the system, the water phase in the emulsion system tends to migrate to the surface, and it is easy to lose water rapidly during the drying process, and the product will be over-dried. Although the Maillard product does not change much visually due to its special color, it will still change in the olfactory sense.

[0005] However, these technical problems do not exist or are difficult to detect in PUFA microcapsules or other fat-soluble nutrient microcapsules with regular content. Summary of the Invention

[0006] In order to solve or at least partially solve the above problems, the present invention provides a polyunsaturated fatty acid oil microcapsule based on the Maillard reaction and a preparation method thereof.

[0007] The first object of the present invention is to provide a method for preparing polyunsaturated fatty acid oil microcapsules based on the Maillard reaction, comprising the following steps:

[0008] (1) Sodium caseinate, glucose and lactose are dissolved in water and mixed evenly, a humectant is added, and the pH of the Maillard reaction is adjusted to 8-10, and an aqueous phase is obtained after the reaction;

[0009] (2) adding polyunsaturated fatty acid oil to the aqueous phase and emulsifying by shearing;

[0010] (3) adding cellulose and its derivatives to the system obtained in step (2), and shearing to obtain an emulsion; the content of cellulose and its derivatives in the polyunsaturated fatty acid oil microcapsules is 0.01-1wt%;

[0011] The mass proportion of polyunsaturated fatty acid oil in the polyunsaturated fatty acid oil microcapsules is not less than 40%, and the content of fatty acids with a carbon chain length of more than 20 and more than 4 unsaturated double bonds in the polyunsaturated fatty acid oil is not less than 40%.

[0012] The present invention adds a humectant in the first step of the Maillard reaction and simultaneously adds a specific amount of cellulose and its derivatives to the emulsified system. Under the premise of unchanged drying process, the rehydration properties of the Maillard microcapsule product with high oil content can be improved while preventing over-drying, thereby improving the sensory perception of the product and ensuring its sensory stability during the shelf life.

[0013] In the present invention, "the content of fatty acids with a carbon chain length of more than 20 and an unsaturated double bond of more than 4 in the polyunsaturated fatty acid oil is not less than 40%" specifically refers to that the content of fatty acids with a carbon chain length of more than 20 and an unsaturated double bond of more than 4 in the polyunsaturated fatty acid oil is not less than 50wt%. In the scheme of the present invention, the polyunsaturated fatty acid oil includes, but is not limited to, one or more of DHA, DPA, EPA, ARA, etc. For example, the DHA oil cited in the present invention contains DPA, EPA, ARA, etc. in addition to DHA, but the main component is DHA. In a preferred embodiment of the present invention, the content of polyunsaturated fatty acid oil in the high-oil-loaded polyunsaturated fatty acid oil microcapsules is 40-55wt%. In addition, the sources of polyunsaturated fatty acid oils include, but are not limited to, plants, deep-sea animals, and microbial fermentation, among which the fermentation of deep-sea fish oil and oil-producing microorganisms such as algae, yeast, and mold is currently the more mainstream source of oil.

[0014] In a preferred embodiment of the present invention, in step (1), in the Maillard reaction, the mass ratio of sodium caseinate, glucose, and lactose is (8-12): (6-12): (6-14). The reaction temperature in step (1) is preferably 80-90°C, and the reaction time is 30-60 minutes. In this step, a pH adjuster such as sodium hydroxide or sodium citrate can be used to adjust the pH of the Maillard reaction to 8-10.

[0015] In a preferred embodiment of the present invention, in step (1), the water-retaining agent is a phosphate, including but not limited to one or more of disodium hydrogen phosphate, sodium dihydrogen phosphate, sodium tripolyphosphate, and trisodium phosphate, and can be selected and matched according to the actual reaction environment and pH regulator. In a preferred embodiment of the present invention, the amount of water-retaining agent added is preferably such that the content of the water-retaining agent in the polyunsaturated fatty acid oil microcapsules is 0.1-0.4wt%. The present invention uses a water-retaining agent to ensure moisture during the drying process. Since phosphate itself has the property of pH regulation, in some specific embodiments, the pH characteristics of the phosphate adjustment system can be adopted, and the use range is maintained within the above range, thereby achieving the dual effects of pH regulation and water retention.

[0016] In a preferred embodiment of the present invention, a filler and / or an antioxidant may be added to the aqueous phase in step (1), preferably after the addition of a humectant and the Maillard reaction. Specifically, step (1) may include the following steps: dissolving sodium caseinate, glucose, and lactose in water and mixing them uniformly; adding a humectant; adjusting the Maillard reaction pH to 8-10; and, after the reaction, adding a filler and / or an antioxidant and mixing them uniformly to obtain an aqueous phase.

[0017] The antioxidants of the present invention include, but are not limited to, one or more of sodium ascorbate, ascorbic acid, ascorbyl palmitate, vitamin E, and phospholipids. In a specific embodiment of the present invention, the antioxidant is added in an amount such that the content of the antioxidant in the polyunsaturated fatty acid oil microcapsules is 3-6wt%. The filler material of the present invention may include, but is not limited to, corn syrup and / or maltodextrin. After the addition of other ingredients, the amount of filler material added is the remainder. The ingredients listed in the present invention are the most commonly used ingredients in the art, and other ingredients can be selected according to the needs of the components.

[0018] In a specific embodiment of the present invention, the shearing conditions in step (2) can be: a shearing speed of 10,000 r / min, and a shearing time of 5-20 min.

[0019] In a preferred embodiment of the present invention, in step (3), cellulose and its derivatives include, but are not limited to, one or more of sodium hydroxymethyl cellulose, sodium carboxymethyl cellulose, and sodium hydroxypropyl cellulose, and are selected based on their ability to dissolve easily in the system without affecting other processes. The present invention selects cellulose and its derivatives with a specific content, and in combination with the other components of the present invention, can improve the moisture retention capacity of the product while reducing the impact of the differences in other components on the product, thereby obtaining a product with better stability and improving the product sensory properties. In a preferred embodiment, the content of cellulose and its derivatives in the polyunsaturated fatty acid oil microcapsules is 0.05-0.3wt%.

[0020] In a specific embodiment of the present invention, the preparation method further comprises the following steps: homogenizing the emulsion obtained in step (3) and spray drying it, and adding an anti-caking agent and dry mixing it.

[0021] In the specific embodiment of the present invention, the homogenization conditions are not limited and can be selected by those skilled in the art. For example, the pressure condition can be: the pressure is conventionally 800 bar. Continuous or discontinuous system equipment can also be selected for implementation.

[0022] In a preferred embodiment of the present invention, the anticaking agent is selected from one or more of tricalcium phosphate, silicon dioxide, microcrystalline cellulose, magnesium stearate. The addition of the anticaking agent is preferably such that the content of the anticaking agent in the polyunsaturated fatty acid oil microcapsule is 0.2-1.0wt%.

[0023] In a preferred embodiment of the present invention, the spray drying conditions are preferably an inlet air temperature of 160-180°C and an outlet air temperature of 60-80°C. In some preferred embodiments, the spray drying pressure is preferably 110-180 bar. Within this pressure range, droplet formation is more favorable during the spray drying process in the system of the present invention.

[0024] The polyunsaturated fatty acid oil microcapsule product based on the Maillard reaction obtained by the preparation method provided by the present invention is not over-dried (under the premise that the drying conditions remain unchanged), thereby improving the product sensory perception while ensuring its stability during the shelf life.

[0025] Another object of the present invention is to provide polyunsaturated fatty acid oil microcapsules obtained by the above preparation method.

[0026] Another object of the present invention is to provide a polyunsaturated fatty acid oil microcapsule based on the Maillard reaction, wherein the polyunsaturated fatty acid oil content in the microcapsule is 40-55wt%, the content of fatty acids with more than 20 carbon chains and more than 4 unsaturated double bonds in the polyunsaturated fatty acid oil is not less than 50wt%, the content of Maillard reaction product is 20-35wt%, the content of cellulose and its derivatives is 0.01-1wt%, the content of humectant is 0.1-0.4wt%, the content of water is 2-4wt%, and the content of antioxidant is 3-6wt%. The reaction raw materials of the Maillard reaction product include sodium caseinate, glucose, and lactose in a mass ratio of (8-12):(6-12):(6-14).

[0027] The preparation method provided by the present invention can improve the rehydration property of Maillard microcapsule products with high oil content, while ensuring that the products are not over-dried, improving the sensory properties (especially the sense of smell) of the products while ensuring their sensory stability during the shelf life. DETAILED DESCRIPTION

[0028] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0029] Except for Comparative Example 4, the component contents of the microcapsules obtained in other Examples and Comparative Examples are shown in Table 1 below. The preparation methods of the Maillard polyunsaturated fatty acid oil microcapsules provided in the Examples and Comparative Examples of the present invention include the following steps:

[0030] a. Dissolve sodium caseinate, glucose, and lactose in water according to the ratio, stir thoroughly, then add a humectant, then adjust the pH to 8.0 with NaOH, raise the temperature to 80°C, hold for 40 minutes, and stir thoroughly;

[0031] b. After the reaction is complete, add the filler material and antioxidant, stir thoroughly to dissolve, and obtain an aqueous phase;

[0032] c. The polyunsaturated fatty acid oil is added to the aqueous phase and sheared at 10,000 r / min for 10 min;

[0033] d. Finally, cellulose and its derivatives were added and sheared for 5 minutes to obtain an emulsion with a solid content of 40%;

[0034] e. The above emulsion is homogenized 2-3 times by a high pressure homogenizer at 800 bar;

[0035] f. Spray drying conditions are inlet air temperature 170±5℃, outlet air temperature 70±5℃, and spray pressure 180bar;

[0036] g. add an anticaking agent and dry mix to obtain.

[0037] Table 1 Content of each component in the microcapsules obtained in Examples and Comparative Examples

[0038]

[0039]

[0040] The contents in parentheses in Table 1 are the mass content of the substance in the resulting polyunsaturated fatty acid oil microcapsules; unless otherwise noted, the contents given are the content of the component in the resulting microcapsules. A "-" indicates that the microcapsules do not contain the component. The DHA oil, derived from algae, contains 40% DHA, and the combined content of fatty acids with four or more unsaturated double bonds, including DHA, EPA, DPA, and ARA, is 60%. The content of all components in the polyunsaturated fatty acid oil microcapsules obtained by the present invention, excluding water, is 100%.

[0041] The ingredients, amounts, and preparation method used in Comparative Example 4 are the same as those in Example 1, except that the aqueous phase is prepared by dissolving sodium caseinate, glucose, and lactose in water and mixing them uniformly, adding a humectant and sodium carboxymethyl cellulose, adjusting the Maillard reaction pH to 8, heating to 80° C., maintaining the temperature for 40 min, stirring thoroughly, adding a filler material and an antioxidant, and stirring thoroughly to dissolve to obtain an aqueous phase.

[0042] Solubility test method: Add 6.5% of the sample to 40°C warm water and start timing. Measure the time it takes for the powder to completely sink below the liquid surface, which is the diffusion rate. Stir the solution at 3 rpm for 15 seconds, then let it sit. Observe the surface and interior of the solution and score the results. "0" indicates no visible insoluble matter; "1" indicates a small amount of insoluble matter; "2" indicates a moderate amount of insoluble matter; "3" indicates a significant amount of insoluble matter; and "4" indicates a significant amount of insoluble matter.

[0043] The appearance and properties of the Maillard polyunsaturated fatty acid oil microcapsules obtained in the Examples and Comparative Examples are shown in Table 2. It is worth mentioning that in Example 3, 0.4% CMC can improve the dissolution properties of the microcapsules, but the high viscosity makes spraying difficult during the process.

[0044] Table 2 Performance of microcapsules

[0045]

[0046] Finally, the method of the present invention is only a preferred embodiment and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing polyunsaturated fatty acid oil microcapsules based on the Maillard reaction, characterized in that: The steps include: (1) Sodium caseinate, glucose and lactose are dissolved in water and mixed evenly, a humectant is added, and the pH of the Maillard reaction is adjusted to 8-10, and an aqueous phase is obtained after the reaction; (2) adding polyunsaturated fatty acid oil to the aqueous phase and emulsifying by shearing; (3) adding cellulose and its derivatives to the system obtained in step (2), and shearing to obtain an emulsion; the content of cellulose and its derivatives in the polyunsaturated fatty acid oil microcapsules is 0.01-1wt%; The mass proportion of polyunsaturated fatty acid oil in the polyunsaturated fatty acid oil microcapsules is not less than 40%, and the content of fatty acids with a carbon chain length of more than 20 and more than 4 unsaturated double bonds in the polyunsaturated fatty acid oil is not less than 40%; In step (1), the content of the moisture retaining agent in the polyunsaturated fatty acid oil microcapsules is 0.1-0.4wt%; the mass ratio of the sodium caseinate, glucose and lactose is (8-12): (6-12): (6-14).

2. The preparation method according to claim 1, characterized in that In step (1), the moisture retaining agent is a phosphate, including but not limited to one or more of disodium hydrogen phosphate, sodium dihydrogen phosphate, sodium tripolyphosphate, and trisodium phosphate.

3. The preparation method according to claim 1, characterized in that In step (3), the cellulose and its derivatives include, but are not limited to, one or more of sodium hydroxymethyl cellulose, sodium carboxymethyl cellulose, and sodium hydroxypropyl cellulose.

4. The preparation method according to any one of claims 1 to 3, characterized in that In step (3), the content of cellulose and its derivatives in the polyunsaturated fatty acid oil microcapsules is 0.05-0.3 wt%.

5. The preparation method according to any one of claims 1 to 3, characterized in that The polyunsaturated fatty acid oils include but are not limited to one or more of DHA, DPA, EPA, and ARA.

6. The preparation method according to any one of claims 1 to 3, characterized in that The content of the polyunsaturated fatty acid oil is 40-55 wt%.

7. The preparation method according to any one of claims 1 to 3, characterized in that The aqueous phase also includes a filling material and / or an antioxidant; the content of the antioxidant in the polyunsaturated fatty acid oil microcapsules is 3-6wt%; the filling material includes but is not limited to solid corn syrup and / or maltodextrin; the antioxidant includes but is not limited to one or more of sodium ascorbate, ascorbic acid, ascorbyl palmitate, vitamin E, and phospholipids.

8. The preparation method according to any one of claims 1 to 3, characterized in that The method also includes the following steps: homogenizing the emulsion and then spray drying it, adding an anti-caking agent and dry mixing it; the anti-caking agent includes but is not limited to one or more of tricalcium phosphate, silicon dioxide, microcrystalline cellulose, and magnesium stearate.

9. The preparation method according to any one of claims 1 to 3, characterized in that In step (1), the reaction temperature is 80-90°C.

10. The polyunsaturated fatty acid oil microcapsules obtained by the preparation method according to any one of claims 1 to 9.

11. A high-oil-load polyunsaturated fatty acid oil microcapsule based on the Maillard reaction, characterized in that: The high-oil-loaded polyunsaturated fatty acid oil microcapsules have a polyunsaturated fatty acid oil content of 40-55wt%, a fatty acid content with more than 20 carbon chains and more than 4 unsaturated double bonds in the polyunsaturated fatty acid oil of not less than 50wt%, a Maillard reaction product content of 20-35wt%, a cellulose and cellulose derivative content of 0.01-1wt%, a moisture retention agent content of 0.1-0.4wt%, a water content of 2-4wt%; and an antioxidant content of 3-6wt%. The reaction raw materials of the Maillard reaction product include sodium caseinate, glucose and lactose in a mass ratio of (8-12): (6-12): (6-14).

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