Preparation method of pomegranate polyphenol sustained-release microcapsule

Abstract

The invention discloses a preparation method of pomegranate polyphenol sustained-release microcapsules, which comprises the following steps: taking composite modified gelatin as a wall material, introducing the composite modified gelatin into an organic solvent, stirring, mixing and dissolving to obtain a first mixed solution; preparing a compound emulsifier; adding a compound emulsifier into the first mixed solution, and carrying out stirring emulsification treatment to obtain an emulsion; adding pomegranate polyphenol into the emulsion, and carrying out ultrasonic dispersion to obtain a second mixed solution; performing high-pressure homogenization treatment on the second mixed solution to obtain a stable emulsion; according to the pomegranate polyphenol sustained-release microcapsule and the preparation method thereof, the pomegranate polyphenol is subjected to microencapsulation, and the pomegranate polyphenol can be wrapped by the sustained-release microcapsule, so that the obtained sustained-release microcapsule can be slowly released according to a preset speed and mode, and the sustained-release function of the pomegranate polyphenol is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of microcapsules, in particular to a method for preparing pomegranate polyphenol sustained-release microcapsules. Background Art

[0002] Pomegranate (Pun icagranatum L.), a plant of the genus Punica of the family Punica, is sweet and sour and has rich nutrients such as amino acids, vitamins, cellulose, minerals, etc. At present, China's pomegranate planting area is about 1.7 million mu, ranking first in the world, with an annual output of more than 1 million tons.

[0003] There are many foods made from pomegranates, such as juice, wine, pomegranate seed oil, etc. However, during the processing of pomegranates, only the pomegranate pulp is needed, and the pomegranate peel, which accounts for 30% of the pomegranate mass, is usually discarded in large quantities, resulting in a large waste of resources.

[0004] Through the chemical composition analysis of pomegranate peel, we can know that pomegranate peel is rich in important active substances such as pomegranate polyphenols, tannins, flavonoids, organic acids, etc., among which pomegranate polyphenols account for 10% to 20% of the dry weight of pomegranate peel, including punicalagin, ellagic acid, gallic acid, catechins, chlorogenic acid and other substances, which have great development value.

[0005] Pomegranate polyphenols have excellent antioxidant ability. In modern life, people are faced with various oxidative stresses such as environmental pollution and radiation, which will accelerate the aging process of the human body. Pomegranate polyphenols can remove free radicals in the body and reduce cell damage, thereby delaying aging. Not only that, it can also protect human skin from oxidative damage and keep the skin young.

[0006] Secondly, pomegranate polyphenols also have the effect of lowering blood lipids. With the improvement of living standards, high blood lipids have become a health problem faced by many people. The polyphenols in pomegranates can block fat deposition and lower blood lipid levels, thereby preventing the occurrence of cardiovascular diseases such as arteriosclerosis and coronary heart disease.

[0007] In addition to the above two points, pomegranate polyphenols also have certain antibacterial properties and help promote wound healing.

[0008] In short, pomegranate polyphenols are a precious natural ingredient with many beneficial effects and functions for the human body. However, although pomegranate polyphenols, as a natural polyphenol, show strong antioxidant properties, due to its low stability and relatively short duration in the intestine, it usually requires taking a larger amount or more times to achieve a certain effect, causing many inconveniences.

[0009] Therefore, the present invention solves the corresponding problems by providing a method for preparing pomegranate polyphenol sustained-release microcapsules. Summary of the invention

[0010] The purpose of the present invention is to provide a method for preparing pomegranate polyphenol sustained-release microcapsules to solve the deficiencies in the prior art.

[0011] The technical solution adopted by the present invention is as follows:

[0012] A method for preparing pomegranate polyphenol sustained-release microcapsules comprises the following steps:

[0013] Taking composite modified gelatin as the wall material, introducing it into an organic solvent, stirring, mixing and dissolving, and obtaining a first mixed solution;

[0014] Wherein, the mixing ratio of the organic solvent to the composite modified gelatin is 6-8:100;

[0015] Prepare compound emulsifier;

[0016] Adding a composite emulsifier to the first mixed liquid, stirring and emulsifying the mixture to obtain an emulsified liquid;

[0017] Wherein, the mixing mass ratio of the first mixed liquid and the compound emulsifier is 100:0.2-0.3;

[0018] Adding pomegranate polyphenols to the emulsion and dispersing by ultrasonication to obtain a second mixed solution;

[0019] Among them, the mixing ratio of pomegranate polyphenols and emulsion is 12-14:100;

[0020] performing high pressure homogenization on the second mixed liquid to obtain a stable emulsion;

[0021] The stable emulsion is spray-dried to obtain pomegranate polyphenol sustained-release microcapsules.

[0022] As a further technical solution: the preparation method of the composite modified gelatin is:

[0023] First, a grafted acid mixture is prepared;

[0024] Propylene glycol alginate was added to 2-morpholineethanesulfonic acid buffer at a volume ratio of 1:1.2, and the mixture was stirred and mixed to obtain a composite buffer;

[0025] The grafted acid mixture is added to the composite buffer solution, and after being evenly mixed, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride are added in sequence, and stirring is continued for 30 minutes, and then the reaction is terminated to obtain a grafted reaction solution;

[0026] Adding gelatin to 2-morpholineethanesulfonic acid buffer, stirring and mixing evenly to obtain a gelatin solution;

[0027] The gelatin and 2-morpholineethanesulfonic acid buffer solution are mixed in a mass ratio of 1:5;

[0028] The grafting reaction liquid was mixed with the gelatin solution, stirred in a water bath for 4 hours, and then the pretreated maltodextrin was added, and the stirring reaction was continued for 6 hours. Then the material was discharged, dialyzed through a 49 mm dialysis bag, and then freeze-dried to obtain the product.

[0029] As a further technical solution: the grafted acid mixture is a mixture of ferulic acid and alginic acid;

[0030] Wherein, the mixing mass ratio of ferulic acid to alginic acid is 0.3:1-1.5.

[0031] As a further technical solution: the concentration of the 2-morpholineethanesulfonic acid buffer is 0.15 mol / L;

[0032] The pH of the 2-morpholineethanesulfonic acid buffer solution is 4.8.

[0033] As a further technical solution: the grafted acid mixture and the composite buffer solution are mixed in a mass ratio of 1-2:10;

[0034] The mass ratio of the composite buffer, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride is 30:1-2:1-1.5:1-2.

[0035] As a further technical solution: the grafting reaction solution and the gelatin solution are mixed in a mass ratio of 1:10-15;

[0036] The mass ratio of the gelatin solution to the pretreated maltodextrin is 20:1-2;

[0037] The preparation method of the pretreated maltodextrin is as follows:

[0038] First, maltodextrin is added into pure water and stirred to obtain a maltodextrin solution;

[0039] Add polyvinyl pyrrolidone and ammonium bicarbonate to the maltodextrin solution, adjust the temperature to 55°C, and stir for 1 hour to obtain a uniform solution;

[0040] The homogeneous solution is spray-dried to obtain a solid powder;

[0041] The solid powder was mixed with anhydrous ethanol at a mass ratio of 1:10 and stirred for 30 minutes, then centrifuged at 8000 r / min for 10 minutes, the supernatant was removed, and then dried at 60° C. for 5 hours to obtain pretreated maltodextrin;

[0042] The spray drying had an inlet air temperature of 175° C., an atomization pressure of 0.32 bar, a feed rate of 550 mL / h, and a nozzle diameter of 4 mm.

[0043] As a further technical solution: the organic solvent is ethyl acetate.

[0044] As a further technical solution: the compound emulsifier is prepared by mixing Span 80 and Span 60;

[0045] Among them, the mixing mass ratio of Span 80 and Span 60 is 1:1.

[0046] As a further technical solution: the high pressure homogenization treatment time is 15-20min;

[0047] The high-pressure homogenization pressure is 32-35MPa.

[0048] As a further technical solution: the spray drying parameters are:

[0049] The inlet air temperature is 155°C, the atomization pressure is 0.35 bar, the outlet air temperature is 68°C, the feed rate is 520 mL / h, and the nozzle diameter is 2 mm.

[0050] Beneficial effects:

[0051] The invention microcapsules pomegranate polyphenols and wraps the pomegranate polyphenols with sustained-release microcapsules, so that the obtained sustained-release microcapsules can be slowly released at a predetermined speed and in a predetermined manner, thereby realizing the sustained-release function of the pomegranate polyphenols.

[0052] The pomegranate polyphenol sustained-release microcapsules prepared by the present invention can prolong the action time of pomegranate polyphenol, and can delay the release and absorption process of pomegranate polyphenol in the body by controlling the diffusion rate of pomegranate polyphenol molecules. In this way, the pomegranate polyphenol can maintain a stable concentration in the body for a long time, thereby improving the durability of the pomegranate polyphenol efficacy.

[0053] Since the pomegranate polyphenol sustained-release microcapsules prepared by the present invention have a longer pomegranate polyphenol release period, the number of uses can be reduced, thereby greatly improving convenience and compliance.

[0054] In microcapsule technology, selecting a suitable wall material is crucial for protecting pomegranate polyphenols, controlling the release rate, and improving the stability and safety of pomegranate polyphenols. Therefore, the present invention prepares composite modified gelatin as the wall material of microcapsules, and through its unique physicochemical properties and biocompatibility, the application range of the prepared microcapsules can be further broadened.

[0055] The composite modified gelatin prepared by the present invention uses gelatin as the main raw material. Gelatin is derived from collagen in animal bones and skins, has a wide source, is low in cost, can reduce immune response and toxicity risks when used in vivo, and is easily absorbed and metabolized by the human body.

[0056] The present invention performs specific treatment on gelatin, and the obtained composite modified gelatin molecules have stronger interactions and can form a stable gel network structure in an aqueous solution. The stable gel network structure can easily wrap the pomegranate polyphenols, thereby forming a uniform and dense microcapsule wall layer, which has a stable and continuous protective effect on the pomegranate polyphenols.

[0057] The wall material made of modified gelatin in the present invention is a special material that can resist the erosion of gastric acid and ensure that the pomegranate polyphenol is not digested in the stomach. When the pomegranate polyphenol enters the small intestine, the shell begins to dissolve and releases the pomegranate polyphenol. At the same time, the microporous structure inside the capsule can control the release rate of the pomegranate polyphenol, so that the pomegranate polyphenol can be released slowly and evenly.

[0058] Direct use of untreated gelatin is easily affected by the environment and denatured, resulting in the inability to maintain the sustained-release function. Therefore, the present invention improves the relative stability of gelatin by performing a specific composite modification treatment, thereby being able to continuously maintain the sustained-release effect, and better prevent the decline in the performance of pomegranate polyphenols caused by oxygen, light, heat and volatilization, thereby ensuring the stability and long-term storage capacity of the pomegranate polyphenol product.

[0059] The inclusion complex formed between the composite modified gelatin prepared by the invention and the pomegranate polyphenol is firmly combined and difficult to separate, and at the same time, its low hygroscopicity helps to maintain the stability of the microcapsule and prolong the shelf life. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a bar graph of the antibacterial performance of each sample after being placed for 7 days in the experiment. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] The following are specific embodiments

[0063] Example 1

[0064] A method for preparing pomegranate polyphenol sustained-release microcapsules comprises the following steps:

[0065] Using composite modified gelatin as a wall material, introducing it into ethyl acetate, stirring, mixing and dissolving, to obtain a first mixed solution;

[0066] Among them, the mixing ratio of organic solvent and composite modified gelatin is 6:100;

[0067] Prepare a compound emulsifier; the compound emulsifier is prepared by mixing Span 80 and Span 60;

[0068] Among them, the mixing mass ratio of Span 80 and Span 60 is 1:1.

[0069] Adding a composite emulsifier to the first mixed liquid, stirring and emulsifying the mixture to obtain an emulsified liquid;

[0070] Wherein, the mixing mass ratio of the first mixed liquid and the compound emulsifier is 100:0.2;

[0071] Adding pomegranate polyphenols to the emulsion and dispersing by ultrasonication to obtain a second mixed solution;

[0072] Among them, the mixing ratio of pomegranate polyphenols and emulsion is 12:100;

[0073] The second mixed liquid was subjected to high-pressure homogenization treatment to obtain a stable emulsion; the high-pressure homogenization treatment time was 15 minutes; and the high-pressure homogenization pressure was 32 MPa.

[0074] The stable emulsion is spray-dried to obtain pomegranate polyphenol sustained-release microcapsules.

[0075] The spray drying parameters are:

[0076] The inlet air temperature is 155°C, the atomization pressure is 0.35 bar, the outlet air temperature is 68°C, the feed rate is 520 mL / h, and the nozzle diameter is 2 mm.

[0077] The preparation method of the composite modified gelatin is as follows:

[0078] First, a grafted acid mixed solution is prepared; the grafted acid mixed solution is prepared by mixing ferulic acid and alginic acid;

[0079] Among them, the mixing mass ratio of ferulic acid and alginate is 0.3:1.

[0080] Propylene glycol alginate was added to 2-morpholineethanesulfonic acid buffer at a volume ratio of 1:1.2, and the mixture was stirred to obtain a composite buffer; the concentration of the 2-morpholineethanesulfonic acid buffer was 0.15 mol / L;

[0081] The pH of the 2-morpholineethanesulfonic acid buffer solution is 4.8.

[0082] The grafted acid mixture is added to the composite buffer solution, and after being evenly mixed, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride are added in sequence, and stirring is continued for 30 minutes, and then the reaction is terminated to obtain a grafted reaction solution;

[0083] Adding gelatin to 2-morpholineethanesulfonic acid buffer, stirring and mixing evenly to obtain a gelatin solution;

[0084] The gelatin and 2-morpholineethanesulfonic acid buffer solution are mixed in a mass ratio of 1:5;

[0085] The grafting reaction liquid was mixed with the gelatin solution, stirred in a water bath for 4 hours, and then the pretreated maltodextrin was added, and the stirring reaction was continued for 6 hours. Then the material was discharged, dialyzed through a 49 mm dialysis bag, and then freeze-dried to obtain the product.

[0086] The mass ratio of the grafted acid mixture to the composite buffer solution is 1:10;

[0087] The mass ratio of the composite buffer, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride is 30:1:1:1.

[0088] The mass ratio of the grafting reaction solution to the gelatin solution was 1:10;

[0089] The mass ratio of the gelatin solution to the pretreated maltodextrin is 20:1;

[0090] The preparation method of the pretreated maltodextrin is as follows:

[0091] First, maltodextrin is added into pure water and stirred to obtain a maltodextrin solution;

[0092] Add polyvinyl pyrrolidone and ammonium bicarbonate to the maltodextrin solution, adjust the temperature to 55°C, and stir for 1 hour to obtain a uniform solution;

[0093] The homogeneous solution is spray-dried to obtain a solid powder;

[0094] The solid powder was mixed with anhydrous ethanol at a mass ratio of 1:10 and stirred for 30 minutes, then centrifuged at 8000 r / min for 10 minutes, the supernatant was removed, and then dried at 60° C. for 5 hours to obtain pretreated maltodextrin;

[0095] The spray drying had an inlet air temperature of 175° C., an atomization pressure of 0.32 bar, a feed rate of 550 mL / h, and a nozzle diameter of 4 mm.

[0096] Example 2

[0097] A method for preparing pomegranate polyphenol sustained-release microcapsules comprises the following steps:

[0098] Using composite modified gelatin as a wall material, introducing it into ethyl acetate, stirring, mixing and dissolving, to obtain a first mixed solution;

[0099] Among them, the mixing ratio of organic solvent and composite modified gelatin is 6.5:100;

[0100] Prepare a compound emulsifier; the compound emulsifier is prepared by mixing Span 80 and Span 60;

[0101] Among them, the mixing mass ratio of Span 80 and Span 60 is 1:1.

[0102] Adding a composite emulsifier to the first mixed liquid, stirring and emulsifying the mixture to obtain an emulsified liquid;

[0103] Wherein, the mixing mass ratio of the first mixed liquid and the compound emulsifier is 100:0.28;

[0104] Adding pomegranate polyphenols to the emulsion and dispersing by ultrasonication to obtain a second mixed solution;

[0105] Among them, the mixing ratio of pomegranate polyphenols and emulsion is 13:100;

[0106] The second mixed liquid was subjected to high-pressure homogenization treatment to obtain a stable emulsion; the high-pressure homogenization treatment time was 16 minutes; and the high-pressure homogenization pressure was 34 MPa.

[0107] The stable emulsion is spray-dried to obtain pomegranate polyphenol sustained-release microcapsules.

[0108] The spray drying parameters are:

[0109] The inlet air temperature is 155°C, the atomization pressure is 0.35 bar, the outlet air temperature is 68°C, the feed rate is 520 mL / h, and the nozzle diameter is 2 mm.

[0110] The preparation method of the composite modified gelatin is as follows:

[0111] First, a grafted acid mixed solution is prepared; the grafted acid mixed solution is prepared by mixing ferulic acid and alginic acid;

[0112] Among them, the mixing mass ratio of ferulic acid and alginate is 0.3:1.

[0113] Propylene glycol alginate was added to 2-morpholineethanesulfonic acid buffer at a volume ratio of 1:1.2, and the mixture was stirred to obtain a composite buffer; the concentration of the 2-morpholineethanesulfonic acid buffer was 0.15 mol / L;

[0114] The pH of the 2-morpholineethanesulfonic acid buffer solution is 4.8.

[0115] The grafted acid mixture is added to the composite buffer solution, and after being evenly mixed, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride are added in sequence, and stirring is continued for 30 minutes, and then the reaction is terminated to obtain a grafted reaction solution;

[0116] Adding gelatin to 2-morpholineethanesulfonic acid buffer, stirring and mixing evenly to obtain a gelatin solution;

[0117] The gelatin and 2-morpholineethanesulfonic acid buffer solution are mixed in a mass ratio of 1:5;

[0118] The grafting reaction liquid was mixed with the gelatin solution, stirred in a water bath for 4 hours, and then the pretreated maltodextrin was added, and the stirring reaction was continued for 6 hours. Then the material was discharged, dialyzed through a 49 mm dialysis bag, and then freeze-dried to obtain the product.

[0119] The mass ratio of the grafted acid mixture to the composite buffer solution is 1.6:10;

[0120] The mass ratio of the composite buffer, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride is 30:1.5:1.2:1.6.

[0121] The mass ratio of the grafting reaction solution to the gelatin solution was 1:13;

[0122] The mass ratio of the gelatin solution to the pretreated maltodextrin is 20:1.8;

[0123] The preparation method of the pretreated maltodextrin is as follows:

[0124] First, maltodextrin is added into pure water and stirred to obtain a maltodextrin solution;

[0125] Add polyvinyl pyrrolidone and ammonium bicarbonate to the maltodextrin solution, adjust the temperature to 55°C, and stir for 1 hour to obtain a uniform solution;

[0126] The homogeneous solution is spray-dried to obtain a solid powder;

[0127] The solid powder was mixed with anhydrous ethanol at a mass ratio of 1:10 and stirred for 30 minutes, then centrifuged at 8000 r / min for 10 minutes, the supernatant was removed, and then dried at 60° C. for 5 hours to obtain pretreated maltodextrin;

[0128] The spray drying had an inlet air temperature of 175° C., an atomization pressure of 0.32 bar, a feed rate of 550 mL / h, and a nozzle diameter of 4 mm.

[0129] Example 3

[0130] A method for preparing pomegranate polyphenol sustained-release microcapsules comprises the following steps:

[0131] Using composite modified gelatin as a wall material, introducing it into ethyl acetate, stirring, mixing and dissolving, to obtain a first mixed solution;

[0132] Among them, the mixing ratio of organic solvent and composite modified gelatin is 7:100;

[0133] Prepare a compound emulsifier; the compound emulsifier is prepared by mixing Span 80 and Span 60;

[0134] Among them, the mixing mass ratio of Span 80 and Span 60 is 1:1.

[0135] Adding a composite emulsifier to the first mixed liquid, stirring and emulsifying the mixture to obtain an emulsified liquid;

[0136] Wherein, the mixing mass ratio of the first mixed liquid and the compound emulsifier is 100:0.25;

[0137] Adding pomegranate polyphenols to the emulsion and dispersing by ultrasonication to obtain a second mixed solution;

[0138] Among them, the mixing ratio of pomegranate polyphenols and emulsion is 13:100;

[0139] The second mixed liquid was subjected to high-pressure homogenization treatment to obtain a stable emulsion; the high-pressure homogenization treatment time was 18 minutes; and the high-pressure homogenization pressure was 34 MPa.

[0140] The stable emulsion is spray-dried to obtain pomegranate polyphenol sustained-release microcapsules.

[0141] The spray drying parameters are:

[0142] The inlet air temperature is 155°C, the atomization pressure is 0.35 bar, the outlet air temperature is 68°C, the feed rate is 520 mL / h, and the nozzle diameter is 2 mm.

[0143] The preparation method of the composite modified gelatin is as follows:

[0144] First, a grafted acid mixed solution is prepared; the grafted acid mixed solution is prepared by mixing ferulic acid and alginic acid;

[0145] Among them, the mixing mass ratio of ferulic acid and alginate is 0.3:1.2.

[0146] Propylene glycol alginate was added to 2-morpholineethanesulfonic acid buffer at a volume ratio of 1:1.2, and the mixture was stirred to obtain a composite buffer; the concentration of the 2-morpholineethanesulfonic acid buffer was 0.15 mol / L;

[0147] The pH of the 2-morpholineethanesulfonic acid buffer solution is 4.8.

[0148] The grafted acid mixture is added to the composite buffer solution, and after being evenly mixed, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride are added in sequence, and stirring is continued for 30 minutes, and then the reaction is terminated to obtain a grafted reaction solution;

[0149] Adding gelatin to 2-morpholineethanesulfonic acid buffer, stirring and mixing evenly to obtain a gelatin solution;

[0150] The gelatin and 2-morpholineethanesulfonic acid buffer solution are mixed in a mass ratio of 1:5;

[0151] The grafting reaction liquid was mixed with the gelatin solution, stirred in a water bath for 4 hours, and then the pretreated maltodextrin was added, and the stirring reaction was continued for 6 hours. Then the material was discharged, dialyzed through a 49 mm dialysis bag, and then freeze-dried to obtain the product.

[0152] The mass ratio of the grafted acid mixture to the composite buffer solution is 1.5:10;

[0153] The mass ratio of the composite buffer, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride is 30:1.5:1.3:1.2.

[0154] The mass ratio of the grafting reaction solution to the gelatin solution was 1:12;

[0155] The mass ratio of the gelatin solution to the pretreated maltodextrin is 20:1.5;

[0156] The preparation method of the pretreated maltodextrin is as follows:

[0157] First, maltodextrin is added into pure water and stirred to obtain a maltodextrin solution;

[0158] Add polyvinyl pyrrolidone and ammonium bicarbonate to the maltodextrin solution, adjust the temperature to 55°C, and stir for 1 hour to obtain a uniform solution;

[0159] The homogeneous solution is spray-dried to obtain a solid powder;

[0160] The solid powder was mixed with anhydrous ethanol at a mass ratio of 1:10 and stirred for 30 minutes, then centrifuged at 8000 r / min for 10 minutes, the supernatant was removed, and then dried at 60° C. for 5 hours to obtain pretreated maltodextrin;

[0161] The spray drying had an inlet air temperature of 175° C., an atomization pressure of 0.32 bar, a feed rate of 550 mL / h, and a nozzle diameter of 4 mm.

[0162] Example 4

[0163] A method for preparing pomegranate polyphenol sustained-release microcapsules comprises the following steps:

[0164] Using composite modified gelatin as a wall material, introducing it into ethyl acetate, stirring, mixing and dissolving, to obtain a first mixed solution;

[0165] Among them, the mixing ratio of organic solvent and composite modified gelatin is 6:100;

[0166] Prepare a compound emulsifier; the compound emulsifier is prepared by mixing Span 80 and Span 60;

[0167] Among them, the mixing mass ratio of Span 80 and Span 60 is 1:1.

[0168] Adding a composite emulsifier to the first mixed liquid, stirring and emulsifying the mixture to obtain an emulsified liquid;

[0169] Wherein, the mixing mass ratio of the first mixed liquid and the compound emulsifier is 100:0.2;

[0170] Adding pomegranate polyphenols to the emulsion and dispersing by ultrasonication to obtain a second mixed solution;

[0171] Among them, the mixing ratio of pomegranate polyphenols and emulsion is 12:100;

[0172] The second mixed liquid was subjected to high-pressure homogenization treatment to obtain a stable emulsion; the high-pressure homogenization treatment time was 15 minutes; and the high-pressure homogenization pressure was 32 MPa.

[0173] The stable emulsion is spray-dried to obtain pomegranate polyphenol sustained-release microcapsules.

[0174] The spray drying parameters are:

[0175] The inlet air temperature is 155°C, the atomization pressure is 0.35 bar, the outlet air temperature is 68°C, the feed rate is 520 mL / h, and the nozzle diameter is 2 mm.

[0176] The preparation method of the composite modified gelatin is as follows:

[0177] First, a grafted acid mixed solution is prepared; the grafted acid mixed solution is prepared by mixing ferulic acid and alginic acid;

[0178] Among them, the mixing mass ratio of ferulic acid and alginate is 0.3:1.

[0179] Propylene glycol alginate was added to 2-morpholineethanesulfonic acid buffer at a volume ratio of 1:1.2, and the mixture was stirred to obtain a composite buffer; the concentration of the 2-morpholineethanesulfonic acid buffer was 0.15 mol / L;

[0180] The pH of the 2-morpholineethanesulfonic acid buffer solution is 4.8.

[0181] The grafted acid mixture is added to the composite buffer solution, and after being evenly mixed, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride are added in sequence, and stirring is continued for 30 minutes, and then the reaction is terminated to obtain a grafted reaction solution;

[0182] Adding gelatin to 2-morpholineethanesulfonic acid buffer, stirring and mixing evenly to obtain a gelatin solution;

[0183] The gelatin and 2-morpholineethanesulfonic acid buffer solution are mixed in a mass ratio of 1:5;

[0184] The grafting reaction liquid was mixed with the gelatin solution, stirred in a water bath for 4 hours, and then the pretreated maltodextrin was added, and the stirring reaction was continued for 6 hours. Then the material was discharged, dialyzed through a 49 mm dialysis bag, and then freeze-dried to obtain the product.

[0185] The mass ratio of the grafted acid mixture to the composite buffer solution is 1:5;

[0186] The mass ratio of the composite buffer, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride is 30:1:1:1.

[0187] The mass ratio of the grafting reaction solution to the gelatin solution was 1:15;

[0188] The mass ratio of the gelatin solution to the pretreated maltodextrin is 10:1;

[0189] The preparation method of the pretreated maltodextrin is as follows:

[0190] First, maltodextrin is added into pure water and stirred to obtain a maltodextrin solution;

[0191] Add polyvinyl pyrrolidone and ammonium bicarbonate to the maltodextrin solution, adjust the temperature to 55°C, and stir for 1 hour to obtain a uniform solution;

[0192] The homogeneous solution is spray-dried to obtain a solid powder;

[0193] The solid powder was mixed with anhydrous ethanol at a mass ratio of 1:10 and stirred for 30 minutes, then centrifuged at 8000 r / min for 10 minutes, the supernatant was removed, and then dried at 60° C. for 5 hours to obtain pretreated maltodextrin;

[0194] The spray drying had an inlet air temperature of 175° C., an atomization pressure of 0.32 bar, a feed rate of 550 mL / h, and a nozzle diameter of 4 mm.

[0195] Example 5

[0196] A method for preparing pomegranate polyphenol sustained-release microcapsules comprises the following steps:

[0197] Using composite modified gelatin as a wall material, introducing it into ethyl acetate, stirring, mixing and dissolving, to obtain a first mixed solution;

[0198] Among them, the mixing ratio of organic solvent and composite modified gelatin is 6:100;

[0199] Prepare a compound emulsifier; the compound emulsifier is prepared by mixing Span 80 and Span 60;

[0200] Among them, the mixing mass ratio of Span 80 and Span 60 is 1:1.

[0201] Adding a composite emulsifier to the first mixed liquid, stirring and emulsifying the mixture to obtain an emulsified liquid;

[0202] Wherein, the mixing mass ratio of the first mixed liquid and the compound emulsifier is 100:0.2;

[0203] Adding pomegranate polyphenols to the emulsion and dispersing by ultrasonication to obtain a second mixed solution;

[0204] Among them, the mixing ratio of pomegranate polyphenols and emulsion is 12:100;

[0205] The second mixed liquid was subjected to high-pressure homogenization treatment to obtain a stable emulsion; the high-pressure homogenization treatment time was 15 minutes; and the high-pressure homogenization pressure was 32 MPa.

[0206] The stable emulsion is spray-dried to obtain pomegranate polyphenol sustained-release microcapsules.

[0207] The spray drying parameters are:

[0208] The inlet air temperature is 155°C, the atomization pressure is 0.35 bar, the outlet air temperature is 68°C, the feed rate is 520 mL / h, and the nozzle diameter is 2 mm.

[0209] The preparation method of the composite modified gelatin is as follows:

[0210] First, a grafted acid mixed solution is prepared; the grafted acid mixed solution is prepared by mixing ferulic acid and alginic acid;

[0211] Among them, the mixing mass ratio of ferulic acid and alginate is 0.3:1.

[0212] Propylene glycol alginate was added to 2-morpholineethanesulfonic acid buffer at a volume ratio of 1:1.2, and the mixture was stirred to obtain a composite buffer; the concentration of the 2-morpholineethanesulfonic acid buffer was 0.15 mol / L;

[0213] The pH of the 2-morpholineethanesulfonic acid buffer solution is 4.8.

[0214] The grafted acid mixture is added to the composite buffer solution, and after being evenly mixed, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride are added in sequence, and stirring is continued for 30 minutes, and then the reaction is terminated to obtain a grafted reaction solution;

[0215] Adding gelatin to 2-morpholineethanesulfonic acid buffer, stirring and mixing evenly to obtain a gelatin solution;

[0216] The gelatin and 2-morpholineethanesulfonic acid buffer solution are mixed in a mass ratio of 1:5;

[0217] The grafting reaction liquid was mixed with the gelatin solution, stirred in a water bath for 4 hours, and then the pretreated maltodextrin was added, and the stirring reaction was continued for 6 hours. Then the material was discharged, dialyzed through a 49 mm dialysis bag, and then freeze-dried to obtain the product.

[0218] The mass ratio of the grafted acid mixture to the composite buffer solution is 1.5:10;

[0219] The mass ratio of the composite buffer, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride is 30:1:1:1.

[0220] The mass ratio of the grafting reaction solution to the gelatin solution was 1:12;

[0221] The mass ratio of the gelatin solution to the pretreated maltodextrin is 20:1.6;

[0222] The preparation method of the pretreated maltodextrin is as follows:

[0223] First, maltodextrin is added into pure water and stirred to obtain a maltodextrin solution;

[0224] Add polyvinyl pyrrolidone and ammonium bicarbonate to the maltodextrin solution, adjust the temperature to 55°C, and stir for 1 hour to obtain a uniform solution;

[0225] The homogeneous solution is spray-dried to obtain a solid powder;

[0226] The solid powder was mixed with anhydrous ethanol at a mass ratio of 1:10 and stirred for 30 minutes, then centrifuged at 8000 r / min for 10 minutes, the supernatant was removed, and then dried at 60° C. for 5 hours to obtain pretreated maltodextrin;

[0227] The spray drying had an inlet air temperature of 175° C., an atomization pressure of 0.32 bar, a feed rate of 550 mL / h, and a nozzle diameter of 4 mm.

[0228] Comparative Example 1:

[0229] On the basis of the technical solution of Example 1, the composite modified gelatin is replaced by untreated gelatin, and the rest of the technical solutions remain unchanged.

[0230] Comparative Example 2:

[0231] Based on the technical solution of Example 1, no pretreated maltodextrin is added during the preparation of the composite modified gelatin, and the rest of the technical solutions remain unchanged.

[0232] test:

[0233] DPPH free radical scavenging ability assay

[0234] The samples of the embodiment and the comparative example were mixed with pure water (mixed at a ratio of 10 mg: 1 mL) to obtain 1 mL of the sample solution and 3.0 mL of a DPPH solution with a concentration of 100 μmol / mL to obtain a mixed solution;

[0235] The mixture was placed in the dark at room temperature for 30 min, and the absorbance was measured at 517 nm. An equal volume of ultrapure water was used for zero setting.

[0236] DPPH clearance rate is calculated as follows:

[0237] DPPH·scavenging rate %=[1-(A1-A2) / A0]×100%;

[0238] Where A0 is the blank group, the absorbance of the mixture of 3mL DPPH and 1mL anhydrous ethanol;

[0239] A1 is the absorbance of a mixture of 3 mL DPPH and 1 mL sample;

[0240] A2 is the control group, the photometric value of 3mL anhydrous ethanol and 1mL sample:

[0241] Table 1

[0242] DPPH·Scavenging rate % Example 1 97.3 Example 2 98.2 Example 3 98.8 Example 4 97.4 Example 5 97.2 Comparative Example 1 97.1 Comparative Example 2 95.6

[0243] It can be seen from Table 1 that the pomegranate polyphenol sustained-release microcapsules prepared in the present invention have high antioxidant activity.

[0244] The samples of the embodiment and the comparative example were left to stand for 7 days in an air atmosphere, and then the DPPH free radical scavenging ability was measured. The measuring method was:

[0245] Table 2

[0246] DPPH·Scavenging rate % Example 1 83.5 Example 2 94.1 Example 3 84.7 Example 4 83.4 Example 5 83.1 Comparative Example 1 68.1 Comparative Example 2 79.7

[0247] It can be seen from Table 2 that the pomegranate polyphenol sustained-release microcapsules prepared by the present invention can greatly reduce the oxidation effect of air on pomegranate polyphenols and can maintain a high oxidation performance for a long time.

[0248] Taking Example 1 as the basic sample, the effects of different time periods on the antioxidant properties of the samples are compared:

[0249] Table 3

[0250]

[0251]

[0252] It can be seen from Table 3 that the antioxidant activity of the samples decreases continuously with the passage of time.

[0253] use

[0254] The diameter of the inhibition zone was measured by the paper disc method as follows:

[0255] In a sterile workbench, take several MH broth agar culture media, add 30 μL of a suspension of a standard strain of Staphylococcus aureus to each medium, spread evenly, and mark well; place a blank drug-sensitive sheet sterilized by high-pressure steam evenly in each culture medium, drop 10 μL of the mixed solution of Example 1 and the comparative sample water (mixed at a ratio of 1 mg: 1 mL) on the drug-sensitive sheet, and culture in a 37°C constant temperature incubator for 12 hours, observe and measure the diameter of the inhibition zone:

[0256] At the same time, the samples of Example 1 and the comparative example were placed in an air atmosphere for 10 days and then tested again:

[0257] Table 4

[0258]

[0259] It can be seen from Table 4 that after being placed for a long time, the pomegranate polyphenol sustained-release microcapsules prepared by the present invention can still maintain excellent antibacterial properties.

[0260] The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the specification, should be within the protection scope of the present invention.

Claims

1. A method for preparing pomegranate polyphenol sustained-release microcapsules, characterized in that: The following steps are involved: Taking composite modified gelatin as the wall material, introducing it into an organic solvent, stirring, mixing and dissolving, and obtaining a first mixed solution; Wherein, the mixing ratio of the organic solvent to the composite modified gelatin is 6-8:100; Prepare compound emulsifier; Adding a composite emulsifier to the first mixed liquid, stirring and emulsifying the mixture to obtain an emulsified liquid; Wherein, the mixing mass ratio of the first mixed liquid and the compound emulsifier is 100:0.2-0.3; Adding pomegranate polyphenols to the emulsion and dispersing by ultrasonication to obtain a second mixed solution; Among them, the mixing ratio of pomegranate polyphenols and emulsion is 12-14:100; performing high pressure homogenization on the second mixed liquid to obtain a stable emulsion; The stable emulsion is spray-dried to obtain pomegranate polyphenol sustained-release microcapsules.

2. The method for preparing a pomegranate polyphenol sustained-release microcapsule according to claim 1, characterized in that: The composite modified gelatin preparation method is: First, a grafted acid mixture is prepared; Propylene glycol alginate was added to 2-morpholineethanesulfonic acid buffer at a volume ratio of 1:1.2, and the mixture was stirred and mixed to obtain a composite buffer; The grafted acid mixture is added to the composite buffer solution, and after being evenly mixed, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride are added in sequence, and stirring is continued for 30 minutes, and then the reaction is terminated to obtain a grafted reaction solution; Adding gelatin to 2-morpholineethanesulfonic acid buffer, stirring and mixing evenly to obtain a gelatin solution; The gelatin and 2-morpholineethanesulfonic acid buffer solution are mixed in a mass ratio of 1:5; The grafting reaction liquid was mixed with the gelatin solution, stirred in a water bath for 4 hours, and then the pretreated maltodextrin was added, and the stirring reaction was continued for 6 hours. Then the material was discharged, dialyzed through a 49 mm dialysis bag, and then freeze-dried to obtain the product.

3. The method for preparing a pomegranate polyphenol sustained-release microcapsule according to claim 2, characterized in that: The grafted acid mixture is prepared by mixing ferulic acid and alginic acid; Wherein, the mixing mass ratio of ferulic acid to alginic acid is 0.3:1-1.

5.

4. The method for preparing a pomegranate polyphenol sustained-release microcapsule according to claim 2, characterized in that: The concentration of the 2-morpholineethanesulfonic acid buffer is 0.15 mol / L; The pH of the 2-morpholineethanesulfonic acid buffer solution is 4.

8.

5. The method for preparing a pomegranate polyphenol sustained-release microcapsule according to claim 2, characterized in that: The mass ratio of the grafted acid mixture to the composite buffer solution is 1-2:10; The mass ratio of the composite buffer, α-cyclodextrin, 5% hydrochloric acid solution and ε-polylysine hydrochloride is 30:1-2:1-1.5:1-2.

6. The method for preparing a pomegranate polyphenol sustained-release microcapsule according to claim 2, characterized in that: The grafting reaction solution and the gelatin solution are mixed in a mass ratio of 1:10-15; The mass ratio of the gelatin solution to the pretreated maltodextrin is 20:1-2; The preparation method of the pretreated maltodextrin is as follows: First, maltodextrin is added into pure water and stirred to obtain a maltodextrin solution; Add polyvinyl pyrrolidone and ammonium bicarbonate to the maltodextrin solution, adjust the temperature to 55°C, and stir for 1 hour to obtain a uniform solution; The homogeneous solution is spray-dried to obtain a solid powder; The solid powder was mixed with anhydrous ethanol at a mass ratio of 1:10 and stirred for 30 minutes, then centrifuged at 8000 r / min for 10 minutes, the supernatant was removed, and then dried at 60° C. for 5 hours to obtain pretreated maltodextrin; The inlet air temperature of the spray drying was 175° C., the atomization pressure was 0.32 bar, the feed rate was 550 mL / h, and the nozzle diameter was 4 mm.

7. The method for preparing a pomegranate polyphenol sustained-release microcapsule according to claim 1, characterized in that: The organic solvent is ethyl acetate.

8. The method for preparing a pomegranate polyphenol sustained-release microcapsule according to claim 1, characterized in that: The compound emulsifier is prepared by mixing Span 80 and Span 60; Among them, the mixing mass ratio of Span 80 and Span 60 is 1:

1.

9. The method for preparing a pomegranate polyphenol sustained-release microcapsule according to claim 1, characterized in that: The high pressure homogenization treatment time is 15-20min; The high-pressure homogenization pressure is 32-35MPa.

10. The method for preparing pomegranate polyphenol sustained-release microcapsules according to claim 1, characterized in that: The spray drying parameters are: The inlet air temperature is 155°C, the atomization pressure is 0.35 bar, the outlet air temperature is 68°C, the feed rate is 520 mL / h, and the nozzle diameter is 2 mm.

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