Instant micro-capsule coated fat powder and preparation method thereof

Abstract

The invention discloses instant micro-capsule coated fat powder and a preparation method thereof, and belongs to the technical field of biological processing, the fat powder comprises the following raw materials by mass: 35-45% of grease; 15%-20% of a cyclodextrin metal organic framework material; 1%-3% of epoxidized soybean lecithin; 20%-25% of a wall material; 0.5%-2% of an emulsifier; and the balance of deionized water. The sum of the mass percentages of the raw materials is 100%, the cyclodextrin metal organic framework realizes molecular-level physical confinement, the epoxidized soybean lecithin serves as a molecular bridge to realize interface chemical crosslinking, the protein-carbohydrate compound wall material completes macroscopic packaging, and the cyclodextrin metal organic framework, the epoxidized soybean lecithin and the protein-carbohydrate compound wall material synergistically construct a compact three-dimensional crosslinking network. High-temperature damage and oxygen permeation are fundamentally blocked, and the problem that the fat powder prepared by a spray drying method is oxidized and loses efficacy in the processing and storage process is solved on the premise of avoiding external addition of an antioxidant.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological processing, and particularly relates to a kind of instant microcapsule coated fat powder and a preparation method thereof. BACKGROUND

[0002] Unsaturated fatty acids refer to a kind of fatty acids with unsaturated chemical bonds in the molecule, which can be divided into monounsaturated fatty acids and polyunsaturated fatty acids according to the number of unsaturated chemical bonds. As important nutrients for animals and humans, unsaturated fatty acids play an important role in regulating nervous system function, participating in inflammatory response, regulating cell signal transduction, and regulating glycolipid metabolism, etc.

[0003] Unsaturated fatty acids are mainly derived from plant oils, fish oils and algal oils, etc. Among them, plant oils (such as soybean oil, rapeseed oil, corn oil, sunflower oil, flaxseed oil, etc.) are more easily obtained due to their wide sources. Adding an appropriate amount of unsaturated fatty acids in livestock and poultry feed can help regulate the body's cellular immune process, thereby having a positive impact on their growth and reproduction performance.

[0004] However, unsaturated fatty acids are usually in liquid state at room temperature, which is inconvenient to add directly to feed. Moreover, the unsaturated double bonds in the molecule are easily oxidized under the influence of external factors such as light, heat and oxygen, resulting in loss of biological activity and nutritional value, and even the production of harmful substances.

[0005] Currently, microcapsule technology is a relatively effective method for protecting unsaturated fatty acids. By developing feed unsaturated fatty acid microcapsules, not only can long-term stable storage, odor masking and improved palatability be achieved, but also the addition and mixing of the microcapsules in feed can be more convenient. For example, the Chinese patent with application number 201110263751.9 discloses a method for preparing high-content fat powder, which selects high-quality coconut oil as raw material and matches different emulsifier combinations to form water-soluble oil with better stability. The fat powder product is obtained by high-pressure homogenization and spray drying. The obtained product has good water solubility, which is beneficial to the digestion and absorption of animals. However, the spray drying process is in a high-temperature environment, which can easily lead to oxidation of heat-sensitive unsaturated fatty acids. At the same time, the obtained powder has a porous structure, and oxygen is more likely to penetrate during storage, which can further exacerbate the oxidative deterioration of the core material, ultimately affecting the activity and safety of the product. In order to control oxidation, current technology usually relies on the addition of antioxidants, but common options such as vitamin E are unstable in effect, while synthetic antioxidants (such as tertiary butyl hydroquinone TBHQ, butylated hydroxyanisole BHA, etc.) have potential safety and residue risks, and their application in feed is limited.

[0006] Therefore, how to overcome the oxidation failure problem of the core material (unsaturated fatty acid) in the process and storage process caused by the high-temperature condition and porous structure of spray drying without adding external antioxidants is a technical problem that needs to be solved at present. SUMMARY

[0007] One of the purposes of the present application is to provide a fast-dissolving microencapsulated fat powder, which overcomes the oxidation failure problem of the fat powder prepared by the spray drying method in the process and storage process without adding external antioxidants.

[0008] The second purpose of the present application is to provide a preparation method of the fast-dissolving microencapsulated fat powder.

[0009] The purpose of the present application can be achieved by the following technical solutions. A fast-dissolving microencapsulated fat powder comprises the following raw materials in mass percentage: 35%-45% of oil and fat; 15%-20% of cyclodextrin metal organic framework material; 1%-3% of epoxidized soy lecithin; 20%-25% of wall material; 0.5%-2% of emulsifier; the balance of deionized water; The sum of the mass percentages of the above raw materials is 100%.

[0010] Further, the wall material comprises protein and carbohydrate, and the mass ratio of the protein and the carbohydrate is 1.5-3:8-9.

[0011] Single wall material has certain limitations in use, such as low embedding rate and poor film forming property, and the wall material is often used in combination in actual production. In the present application, the protein and carbohydrate compound are used as the wall material. On the one hand, when the protein molecules contact with the oil and fat, the hydrophobic groups are adsorbed on the surface of the oil and fat, and the hydrophilic groups penetrate into the water phase, tightly combine with the water and the oil, and form an emulsion. After the addition of the carbohydrate, the carbohydrate is embedded in the protein matrix, which improves the stability of the protein film, increases the thickness, strength and density of the microcapsule film, and further improves the stability of the fat powder.

[0012] Further, the protein is at least one of soybean protein isolate, soybean protein concentrate, wheat protein, whey protein isolate, whey protein concentrate, sodium caseinate and gelatin protein.

[0013] Further, the carbohydrate is at least one of glucose, sucrose, lactose, trehalose, maltodextrin, starch syrup and sodium octenyl succinate starch.

[0014] Further, the emulsifier is a mixture of tri-glycerol monostearate and sucrose ester in a mass ratio of 2-3:1-3.

[0015] Further, the oil and fat is at least one of soybean oil, corn oil, coconut oil, flaxseed oil, fish oil and algal oil.

[0016] Further, the raw material for preparing the cyclodextrin metal organic framework material comprises cyclodextrin and potassium hydroxide.

[0017] Further, the cyclodextrin is beta-cyclodextrin and / or gamma-cyclodextrin, preferably gamma-cyclodextrin, and the oil and fat molecule is large in size, and the cyclodextrin metal organic framework material prepared by using gamma-cyclodextrin as the raw material has larger cavities and pore sizes, can more effectively load the oil and fat molecules, reduces the gap mismatch, and obtains higher embedding rate.

[0018] Further, the preparation steps of the cyclodextrin metal organic framework material are as follows: The cyclodextrin and potassium hydroxide are added into deionized water and stirred uniformly, the filtrate is filtered and taken out to be placed in a beaker, methanol is sealed in a chromatography cylinder for one week, methanol vapor is diffused into the solution in the beaker, centrifugation is performed, the supernatant is removed, the precipitate is washed with methanol and then vacuum dried, and the cyclodextrin metal organic framework material is obtained.

[0019] Further, the usage ratio of the cyclodextrin, potassium hydroxide, deionized water and methanol is 1 mmol:8 mmol:20-40 mL:100-120 mL, and a filter membrane with a pore size of 0.45 um is used for filtration.

[0020] As a natural inclusion material, cyclodextrin is a kind of cyclic oligosaccharide with a hydrophobic cavity and a hydrophilic outer wall structure, and it is non-toxic, porous and soluble in water, and can form a relatively stable inclusion compound with guest molecules in an aqueous solution, and is used for microcapsule preparation. However, the traditional cyclodextrin has inherent limitations in coating oil and fat molecules: the single ring cavity size is limited, and there is a "gap mismatch" problem with substances with larger molecular sizes in vegetable oil, resulting in low embedding rate and insufficient stability of the inclusion compound, so that the final fat powder product is prone to core material leakage and oxidation during storage, and the overall stability is poor.

[0021] To this end, the cyclodextrin metal organic framework material is used to replace the traditional cyclodextrin, and the material is formed by using cyclodextrin molecules as organic ligands and K + The three-dimensional ordered, porous and crystalline network structure formed by coordination bonds not only has good biocompatibility, but also has high specific surface area and large pore size, which provides more abundant and higher matching physical accommodation space for oil and fat molecules, can realize higher loading capacity and embedding rate, and solves the problem of incomplete coating caused by insufficient space.

[0022] In addition, the traditional cyclodextrin mainly relies on weak van der Waals force for inclusion, while the three-dimensional crystal framework of the cyclodextrin metal organic framework material can produce a stronger "physical confinement" effect on the embedded oil molecules. This structure can more effectively limit the movement, aggregation and outward diffusion of oil molecules during subsequent spray drying, high temperature impact and storage, providing a stronger physical barrier for the core material, which is beneficial to improve the storage stability of the fat powder.

[0023] Further, the preparation steps of the epoxidized soy lecithin are as follows: The soy lecithin, catalyst and acetic acid are uniformly mixed, hydrogen peroxide is added dropwise at a temperature of 55-65 DEG C, after the dropwise addition is completed, the reaction is kept for 5-7 h, after the reaction is completed, the pH is adjusted to 7-8 with sodium hydroxide solution, filtration, and the filtrate is distilled under reduced pressure to remove water to obtain epoxidized soy lecithin.

[0024] Further, the catalyst is used in an amount of 8%-11% of the mass of the soy lecithin, the acetic acid is used in an amount of 5%-6% of the mass of the soy lecithin, and the hydrogen peroxide is used in an amount of 80%-100% of the mass of the soy lecithin, and the mass fraction of the hydrogen peroxide is 27.5%-35%.

[0025] Further, the catalyst is pretreated 732# cation exchange resin, and the preparation steps are as follows: The 732# cation exchange resin is soaked in distilled water for 12 h, then taken out, and then soaked in a sodium chloride ethanol solution composed of sodium chloride and anhydrous ethanol in a mass ratio of 1:100 for 24 h, taken out, then soaked in a 5%-8% hydrochloric acid solution for 3-5 h, taken out, finally washed with water until the pH of the effluent is 4-5, and dried.

[0026] Soy lecithin is a natural amphiphilic substance extracted from soybean oil, which contains both hydrophobic groups and hydrophilic groups in the molecule, and thus has excellent emulsifying, dispersing and wetting properties, and is a high-efficiency natural emulsifier. However, the unsaturated double bond existing in the molecular chain makes it easy to be oxidized, which limits its application in systems requiring high oxidative stability to some extent.

[0027] To solve this problem, the soy lecithin is epoxidized in the present application. On the one hand, the unstable carbon-carbon double bond is converted into a more stable epoxy group, which fundamentally eliminates the structural hidden danger of easy oxidation; on the other hand, the newly introduced epoxy group has high reactivity and can be used as an active site for subsequent chemical modification (such as cross-linking with protein or polysaccharide wall material). These two improvements together lay the material foundation for the preparation of high-quality microencapsulated fat powder products with excellent oxidative stability.

[0028] The preparation method of the instant microencapsulated fat powder comprises the following steps: S1, mix the wall material, cyclodextrin metal organic framework material, deionized water and total mass 1 / 2 emulsifier, stir and mix at 50-80 DEG C for 15-30 min, to obtain the water phase wall material; S2, mix the oil and the remaining emulsifier, stir and mix at 70-80 DEG C for 15-30 min, to obtain the oil phase core material; S3, mix the water phase wall material and the oil phase core material uniformly, and add sodium hydroxide solution to adjust the pH to 8-9, then add epoxidized soy lecithin, stir and react at 40-50 DEG C for 2-4 h, then neutralize with hydrochloric acid solution to pH 7, to obtain the initial emulsion, pass through homogenization to obtain the final emulsion, spray dry the final emulsion to obtain the instant microencapsulated fat powder.

[0029] Further, the concentration of the sodium hydroxide solution is 1-3 mol / L, and the concentration of the hydrochloric acid solution is 1-3 mol / L.

[0030] Further, the homogenization conditions are: homogenization speed of 8000-12000 r / min, homogenization time of 10-20 min, and homogenization temperature of 20-30 DEG C.

[0031] Further, the nozzle pressure in the spray drying process is 0.15-0.2 MPa, the drying inlet air temperature is 170-180 DEG C, and the outlet air temperature is 80-85 DEG C.

[0032] In the preparation process of the fat powder, the epoxidized soy lecithin is introduced, which plays a role of emulsification and compatibilization on one hand, and on the other hand, the epoxy groups in the molecule of the substance can react with the hydroxyl groups on the surface of the cyclodextrin metal organic framework material, and the amino or hydroxyl groups in the protein / carbohydrate molecules in the wall material, to form a three-dimensional covalent network structure connecting the core carrier and the wall material at the oil-water interface and in the entire water phase matrix; the formation of the crosslinked network can effectively enhance the continuity and compactness of the microcapsule wall layer. On one hand, it can reduce the wall material defects and pores caused by incomplete physical embedding through chemical bond fixation, thereby minimizing the content of "surface oil" that is not effectively embedded. On the other hand, the formed compact three-dimensional network itself is an excellent physical barrier, which can significantly hinder the penetration and diffusion of oxygen molecules, thereby imparting better oxygen barrier performance and long-term storage stability to the fat powder product.

[0033] The beneficial effects of the present application are: 1.The present application provides a kind of instant microcapsule coated fat powder, and a three-level synergistic protection system of "molecular embedding-interface crosslinking-wall material encapsulation" is constructed.Cyclodextrin metal organic framework realizes molecular level physical confinement, epoxidized soy lecithin realizes interface chemical crosslinking as "molecular bridge", and protein-carbohydrate compound wall material completes macroscopic encapsulation, and the three cooperatively build a dense three-dimensional crosslinked network, which fundamentally blocks high-temperature damage and oxygen permeation, avoids the addition of antioxidants, and overcomes the oxidation failure of fat powder prepared by spray drying method during processing and storage.

[0034] 2.In the present application, the three-dimensional porous network of cyclodextrin metal organic framework material provides more space for oil and fat loading, solving the "void mismatch" problem of traditional materials.This physical confinement effect can more effectively isolate oxygen, heat and other factors from the structure, providing a solid primary barrier for the core material.

[0035] 3.The present application epoxidizes soy lecithin, which not only eliminates its own oxidation risk, but also introduces highly reactive epoxy groups.These groups can crosslink with cyclodextrin metal organic framework material and wall material molecules, forming a dense three-dimensional covalent network at the interface, significantly enhancing the continuity of the wall layer and reducing defects, thereby actively improving the overall antioxidant and mechanical stability of the system.

[0036] 4.The present application ensures high embedding rate and low surface oil characteristics of fat powder through precise raw material ratio and mild and efficient crosslinking reaction process.The final product not only solves the problem of thermal oxidation damage during spray drying, but also achieves excellent storage stability, realizing the production of high-quality and stable feed fat powder without relying on external synthetic antioxidants. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application, obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments.Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0038] Obviously, the following description is only some examples or embodiments of the present application, and for those skilled in the art, the present application can be applied to other similar situations without creative labor.In addition, it can be understood that although the effort made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in the present application, some design, manufacture or production changes based on the technical content disclosed in the present application are only routine technical means, and should not be understood as insufficient disclosure of the present application.

[0039] However, there are cases where unnecessary detailed description is omitted. For example, there are cases where detailed description of matters well known, repeated description of actually identical structures is omitted. This is to avoid the following description becoming unnecessarily lengthy and facilitate understanding by those skilled in the art. In addition, the following description is provided in order for those skilled in the art to fully understand the present application and is not intended to limit the subject matter recited in the claims.

[0040] If not specifically stated, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0041] The following will be specifically described in combination with examples. In the following examples and comparative examples, the purity of soybean lecithin (97% acetone insoluble) is 98%, which is purchased from Shaanxi Xintianyu Biotechnology Co., Ltd.; the first grade soybean oil is "Jiuji" first grade soybean oil, which is provided by Anhui Wuji Fang Tea Oil Co., Ltd.; the corn oil has a purity of 99.9%, which is purchased from Shandong Ruisheng Pharmaceutical Auxiliary Material Co., Ltd.; the coconut oil has a purity of 99%, which is purchased from Yikang Natural Spice Oil Refining Factory in Jishui County; the soybean protein isolate has a purity of 99%, which is purchased from Guangzhou Hengtian Biotechnology Co., Ltd.; the sodium octenyl succinate starch and sucrose ester have a purity of 99%, which are purchased from Nanjing Songguan Biotechnology Co., Ltd.

[0042] Preparation Example 1

[0043] A cyclodextrin metal organic framework material, the preparation steps are as follows: 10 mmol of γ-cyclodextrin and 80 mmol of potassium hydroxide were added to 200 mL of deionized water and stirred uniformly, filtered with a filter membrane with a pore size of 0.45 um, and the filtrate was placed in a beaker. 1000 mL of methanol was sealed in a chromatography cylinder for one week, so that the methanol vapor diffused into the solution in the beaker. After centrifugation, the supernatant was removed, and the precipitate was washed with methanol and then vacuum dried to obtain a cyclodextrin metal organic framework material.

[0044] Preparation Example 2

[0045] A cyclodextrin metal organic framework material, the preparation steps are as follows: 10 mmol of γ-cyclodextrin and 80 mmol of potassium hydroxide were added to 400 mL of deionized water and stirred uniformly, filtered with a filter membrane with a pore size of 0.45 um, and the filtrate was placed in a beaker. 1200 mL of methanol was sealed in a chromatography cylinder for one week, so that the methanol vapor diffused into the solution in the beaker. After centrifugation, the supernatant was removed, and the precipitate was washed with methanol and then vacuum dried to obtain a cyclodextrin metal organic framework material.

[0046] Preparation Example 3

[0047] An epoxidized soy lecithin, the preparation steps are as follows: 10g of soy lecithin, 0.8g of pretreated 732# cation exchange resin and 0.5g of acetic acid are uniformly mixed, 8g of 27.5wt% hydrogen peroxide is added dropwise at 55℃, after the dropwise addition is completed, the reaction is kept for 5h, after the reaction is completed, the pH is adjusted to 7 with sodium hydroxide solution, filtration is performed, and the filtrate is distilled under reduced pressure to remove water to obtain the epoxidized soy lecithin.

[0048] The pretreated 732# cation exchange resin has the following preparation steps: The 732# cation exchange resin is soaked in distilled water for 12h, then taken out, soaked in a sodium chloride ethanol solution composed of sodium chloride and anhydrous ethanol according to a mass ratio of 1:100 for 24h, taken out, then soaked in a 5% hydrochloric acid solution for 3h, taken out, finally washed with water until the effluent has a pH of 4, and dried.

[0049] Preparation Example 4

[0050] An epoxidized soy lecithin, the preparation steps are as follows: 10g of soy lecithin, 1.1g of pretreated 732# cation exchange resin and 0.6g of acetic acid are uniformly mixed, 10g of 35wt% hydrogen peroxide is added dropwise at 65℃, after the dropwise addition is completed, the reaction is kept for 7h, after the reaction is completed, the pH is adjusted to 8 with sodium hydroxide solution, filtration is performed, and the filtrate is distilled under reduced pressure to remove water to obtain the epoxidized soy lecithin.

[0051] The pretreated 732# cation exchange resin has the following preparation steps: The 732# cation exchange resin is soaked in distilled water for 12h, then taken out, soaked in a sodium chloride ethanol solution composed of sodium chloride and anhydrous ethanol according to a mass ratio of 1:100 for 24h, taken out, then soaked in an 8% hydrochloric acid solution for 5h, taken out, finally washed with water until the effluent has a pH of 5, and dried.

[0052] Example 1

[0053] A fast-dissolving microencapsulated fat powder, comprising the following raw materials in mass percentage: 35% of oil and fat; 15% of the cyclodextrin metal organic framework material of Preparation Example 1; 1% of the epoxidized soy lecithin of Preparation Example 3; 20% of wall material; 0.5% of emulsifier; the balance of deionized water; The sum of the mass percentages of the above raw materials is 100%.

[0054] The oil is composed of first-grade soybean oil, corn oil and coconut oil in a mass ratio of 50:4:10, the wall material is composed of soybean protein isolate and sodium octenyl succinate starch in a mass ratio of 1.5:8, and the emulsifier is a mixture of triacylglycerol monostearate and sucrose ester in a mass ratio of 2:1.

[0055] The preparation method of the instant micro-capsule coated fat powder comprises the following steps: S1, mixing the wall material, the cyclodextrin metal organic framework material, deionized water and 1 / 2 of the total mass of the emulsifier, stirring and mixing at 50 DEG C for 30 min to obtain the water phase wall material; S2, mixing the oil and the remaining emulsifier, stirring and mixing at 70 DEG C for 30 min to obtain the oil phase core material; S3, uniformly mixing the water phase wall material and the oil phase core material, adding 1 mol / L sodium hydroxide solution to adjust the pH to 8, then adding the epoxidized soybean lecithin, stirring and reacting at 40 DEG C for 2 h, then neutralizing with 1 mol / L hydrochloric acid solution to pH 7 to obtain the initial emulsion, homogenizing to obtain the final emulsion, spray drying the final emulsion to obtain the instant micro-capsule coated fat powder.

[0056] The homogenization conditions are: homogenization speed of 8000 r / min, homogenization time of 10 min, and homogenization temperature of 20 DEG C; the nozzle pressure during spray drying is 0.15 MPa, the drying inlet air temperature is 170 DEG C, and the outlet air temperature is 80 DEG C.

[0057] Example 2

[0058] An instant micro-capsule coated fat powder comprises the following raw materials in mass percentage: Oil 40%; The cyclodextrin metal organic framework material of Preparation Example 1 18%; The epoxidized soybean lecithin of Preparation Example 3 2%; Wall material 22%; Emulsifier 1%; Deionized water balance; The sum of the mass percentages of the above raw materials is 100%.

[0059] The oil is composed of first-grade soybean oil, corn oil and coconut oil in a mass ratio of 53:5:12, the wall material is composed of soybean protein isolate and sodium octenyl succinate starch in a mass ratio of 2:8.5, and the emulsifier is a mixture of triacylglycerol monostearate and sucrose ester in a mass ratio of 2.5:2.

[0060] The preparation method of the instant micro-capsule coated fat powder comprises the following steps: S1, mix the wall material, cyclodextrin metal organic framework material, deionized water and half of the total mass of emulsifier, stir and mix at 70℃ for 20min to obtain the water phase wall material; S2, mix the oil and the remaining emulsifier, stir and mix at 75℃ for 20min to obtain the oil phase core material; S3, mix the water phase wall material and the oil phase core material uniformly, add 2mol / L sodium hydroxide solution to adjust the pH to 8, then add the epoxidized soy lecithin, stir and react at 45℃ for 3h, then neutralize to pH 7 with 2mol / L hydrochloric acid solution to obtain the primary emulsion, homogenize to obtain the final emulsion, spray dry the final emulsion to obtain the instant microencapsulated fat powder.

[0061] The homogenization conditions are: homogenization speed is 10000r / min, homogenization time is 15min, and homogenization temperature is 25℃; the nozzle pressure during spray drying is 0.15MPa, the drying inlet air temperature is 175℃, and the outlet air temperature is 83℃.

[0062] Example 3

[0063] An instant microencapsulated fat powder, comprising the following mass percentages of raw materials: Oil 45%; Cyclodextrin metal organic framework material of Preparation Example 1 20%; Epoxidized soy lecithin of Preparation Example 3 1%; Wall material 20%; Emulsifier 1%; Deionized water balance; The sum of the mass percentages of the above raw materials is 100%.

[0064] The oil is composed of first grade soybean oil, corn oil and coconut oil in a mass ratio of 55:6:15, the wall material is composed of soybean protein isolate and octenyl succinic anhydride sodium starch in a mass ratio of 3:9, and the emulsifier is a mixture of triacylglycerol monostearate and sucrose ester in a mass ratio of 3:1.

[0065] The preparation method of the instant microencapsulated fat powder comprises the following steps: S1, mix the wall material, cyclodextrin metal organic framework material, deionized water and half of the total mass of emulsifier, stir and mix at 80℃ for 30min to obtain the water phase wall material; S2, mix the oil and the remaining emulsifier, stir and mix at 80℃ for 30min to obtain the oil phase core material; S3, the water phase wall material and the oil phase core material are mixed uniformly, and a 3 mol / L sodium hydroxide solution is added to adjust the pH to 9, then epoxidized soybean lecithin is added, and stirred at 50℃ for 4h, then neutralized to pH 7 with a 3 mol / L hydrochloric acid solution, to obtain a primary emulsion, which is homogenized to obtain a final emulsion, which is spray dried to obtain a fat powder coated with instant microcapsules.

[0066] The homogenization conditions are: homogenization speed of 12000r / min, homogenization time of 20min, and homogenization temperature of 30℃. In the spray drying process, the nozzle pressure is 0.2MPa, the drying inlet air temperature is 180℃, and the outlet air temperature is 85℃.

[0067] Example 4

[0068] A fat powder coated with instant microcapsules, compared with Example 1, the only difference is that the cyclodextrin metal organic framework material in Example 1 is replaced by the product obtained in Preparation Example 2.

[0069] Example 5

[0070] A fat powder coated with instant microcapsules, compared with Example 1, the only difference is that the epoxidized soybean lecithin in Example 1 is replaced by the product obtained in Preparation Example 4.

[0071] Example 6

[0072] A fat powder coated with instant microcapsules, compared with Example 2, the only difference is that the cyclodextrin metal organic framework material in Example 2 is replaced by the product obtained in Preparation Example 2.

[0073] Example 7

[0074] A fat powder coated with instant microcapsules, compared with Example 2, the only difference is that the epoxidized soybean lecithin in Example 2 is replaced by the product obtained in Preparation Example 4.

[0075] Example 8

[0076] A fat powder coated with instant microcapsules, compared with Example 3, the only difference is that the cyclodextrin metal organic framework material in Example 3 is replaced by the product obtained in Preparation Example 2.

[0077] Example 9

[0078] A fat powder coated with instant microcapsules, compared with Example 3, the only difference is that the epoxidized soybean lecithin in Example 3 is replaced by the product obtained in Preparation Example 4.

[0079] Comparative Example 1

[0080] A fat powder coated with instant microcapsules, which differs from Example 1 only in that the cyclodextrin metal organic framework material in Example 1 is replaced by equal mass γ-cyclodextrin.

[0081] Comparative Example 2

[0082] A fat powder coated with instant microcapsules, which differs from Example 1 only in that the epoxidized soy lecithin in Example 1 is replaced by equal mass soy lecithin.

[0083] Comparative Example 3

[0084] A fat powder coated with instant microcapsules, which differs from Example 1 only in that the cyclodextrin metal organic framework material in Example 1 is replaced by equal mass γ-cyclodextrin, and the epoxidized soy lecithin is replaced by equal mass soy lecithin.

[0085] Comparative Example 4

[0086] A fat powder coated with instant microcapsules, which differs from Example 1 only in that the soy protein isolate in Example 1 is replaced by equal mass sodium octenyl succinate starch.

[0087] Comparative Example 5

[0088] A fat powder coated with instant microcapsules, which differs from Example 1 only in that the sodium octenyl succinate starch in Example 1 is replaced by equal mass soy protein isolate.

[0089] The fat powders coated with instant microcapsules obtained in Examples 1-9 and Comparative Examples 1-5 are tested, and the testing process is as follows: (1) Stability of the final emulsion: the final emulsion in the preparation process of each group of fat powders is loaded into a centrifuge tube with scale, centrifuged at 3000 r / min for 10 min, and the height of the emulsion layer and the free water layer is observed, and the formula E (stability of the final emulsion) = (1-h1 / h0) x 100%, wherein h1 is the height of the emulsion layer, cm; h0 is the total height of the liquid in the centrifuge tube, cm; (2) Solubility of the fat powder: 10 g of each group of fat powder is taken and added to 100 mL of 25°C deionized water, and under 500 r / min magnetic stirring, the complete dissolution time of the fat powder is observed, and when completely dissolved, no undispersed particles are observed by visual observation; (3) Embedding rate: take 3g of fat powder (mass is marked as m) of each group, accurately extract with 40mL of petroleum ether under slight stirring for 1min, immediately filter with a sand core funnel, wash the filter residue with 25mL of petroleum ether for 40s, immediately filter, transfer the filtrate to a constant weight conical flask (mass is marked as m1), evaporate the petroleum ether and dry at 65℃ under vacuum until constant weight (mass is marked as m2), test the surface oil content: surface oil = (m2-m1) / m x 100%; apply basic diethyl ether extraction method to determine the total fat content in the product: total fat content = extracted oil content / fat powder sample mass x 100%; then calculate the embedding rate: embedding rate = (total fat content-surface oil content) / total fat content x 100%; (4) Peroxide value determination: adopt accelerated oxidation test by Schaal oven method, fill each group of fat powder into a wide-mouth reagent bottle, test the initial oxidation value, then place in a constant temperature oven at (62+0.5)℃ with good air convection for 60h, take samples every 30h, extract oil by ultrasonic method and determine the peroxide value of the extracted oil according to the method of GB / T 5009.37-2003. Each sample is repeated 3 times to take the average value. The test results are shown in Table 1: Table 1 Performance test result statistics table of instant microcapsule coated fat powder of examples and comparative examples

[0090] It can be seen from the data recorded in Table 1 that the stability of the final emulsion obtained in Examples 1-9 is ≥99.2%, the complete dissolution time is ≤58s, the embedding rate is ≥97.6%, the initial peroxide value is ≤1.5mmol / kg, the 30h peroxide value is ≤1.7mmol / kg, and the 60h peroxide value is ≤2.3mmol / kg, indicating that the final emulsion prepared by the present application has high stability and is more suitable for spray drying process. In addition, the obtained fat powder has high embedding rate and high stability, and has a longer effective period; It can be seen from the test results of Example 1 and Comparative Example 1 that replacing the cyclodextrin metal organic framework material in Example 1 with γ-cyclodextrin significantly reduces the embedding rate of the obtained fat powder and significantly increases the initial, 30h and 60h peroxide values, indicating that using cyclodextrin metal organic framework material is more conducive to obtaining high-quality fat powder; It can be seen from the test results of Example 1 and Comparative Example 2 that replacing the epoxidized soy lecithin in Example 1 with lecithin also significantly reduces the embedding rate of the obtained fat powder and significantly increases the initial, 30h and 60h peroxide values, indicating that using epoxidized soy lecithin is more conducive to obtaining high-quality fat powder; It can be seen from the test results of Example 1 and Comparative Example 3 that using cyclodextrin metal organic framework material and epoxidized soy lecithin is more conducive to obtaining high-quality fat powder; It can be seen from the test results of example 1, comparative example 4 and comparative example 5 that the stability of the fat powder is better and the embedding rate is larger when the soybean protein isolate and sodium octenyl succinate starch compound product are used as the wall material compared with single use; In summary, in the preparation process of the microcapsule-coated fat powder, the molecular level physical confinement is realized by using the cyclodextrin metal organic framework, the interface chemical cross-linking is realized by using the epoxidized soy lecithin as a "molecular bridge", the macroscopic encapsulation is completed by using the protein-carbohydrate compound wall material, and a dense three-dimensional cross-linked network is formed by the synergistic effect of the three, which fundamentally blocks the damage of high temperature and the penetration of oxygen, avoids the addition of antioxidants, and overcomes the oxidation failure problem of the fat powder prepared by the spray drying method in the process of processing and storage.

[0091] It should be noted that, in this document, the terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0092] Although the embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A fast-dissolving microencapsulated fat powder, characterized in that, Including the following percentages by weight of raw materials: Oil content: 35%-45%; Cyclodextrin metal-organic framework materials: 15%-20%; Epoxidized soybean lecithin 1%-3%; Wall material 20%-25%; Emulsifier 0.5%-2%; Deionized water balance; The sum of the above raw material mass percentages is 100%.

2. The fast-dissolving microencapsulated fat powder according to claim 1, characterized in that, The wall material comprises protein and carbohydrates, with a mass ratio of protein to carbohydrates of 1.5-3:8-9.

3. The fast-dissolving microencapsulated fat powder according to claim 2, characterized in that, The protein is at least one of soy protein isolate, soy protein concentrate, wheat protein, whey protein isolate, whey protein concentrate, sodium caseinate, and gelatin protein, and the carbohydrate is at least one of glucose, sucrose, lactose, trehalose, maltodextrin, starch syrup, and sodium octenyl succinate.

4. The fast-dissolving microencapsulated fat powder according to claim 1, characterized in that, The emulsifier is a mixture of triglyceride monostearate and sucrose ester in a mass ratio of 2-3:1-3.

5. The fast-dissolving microencapsulated fat powder according to claim 1, characterized in that, The oil is at least one of soybean oil, corn oil, coconut oil, flaxseed oil, fish oil, and algae oil.

6. The fast-dissolving microencapsulated fat powder according to claim 1, characterized in that, The raw materials for preparing the cyclodextrin metal-organic framework material include cyclodextrin and potassium hydroxide, wherein the cyclodextrin is β-cyclodextrin and / or γ-cyclodextrin.

7. A fast-dissolving microencapsulated fat powder according to claim 1 or 6, characterized in that, The preparation steps of the cyclodextrin metal-organic framework material are as follows: Cyclodextrin and potassium hydroxide were added to deionized water and stirred until homogeneous. The filtrate was filtered and placed in a beaker. The beaker was sealed with methanol in a chromatography tank for one week to allow methanol vapor to diffuse into the solution. After centrifugation, the supernatant was removed, and the precipitate was washed with methanol and then dried under vacuum to obtain the cyclodextrin metal-organic framework material.

8. The fast-dissolving microencapsulated fat powder according to claim 7, characterized in that, The ratio of cyclodextrin, potassium hydroxide, deionized water and methanol was 1 mmol: 8 mmol: 20-40 mL: 100-120 mL, and filtration was performed using a 0.45 μm filter membrane.

9. A method for preparing fast-dissolving microencapsulated fat powder, characterized in that, The preparation of the fast-dissolving microcapsule-coated fat powder according to any one of claims 1-8 includes the following steps: S1. Mix the wall material, cyclodextrin metal-organic framework material, deionized water and 1 / 2 of the total mass of emulsifier, and stir at 50-80℃ for 15-30 min to obtain the aqueous wall material. S2. Mix the grease and the remaining emulsifier, and stir at 70-80℃ for 15-30 minutes to obtain the oil phase core material; S3. Mix the aqueous wall material and oil core material evenly, and add sodium hydroxide solution to adjust the pH to 8-9. Then add epoxidized soybean lecithin and stir the reaction at 40-50℃ for 2-4 hours. Then neutralize with hydrochloric acid solution to pH 7 to obtain the primary emulsion. After homogenization, obtain the final emulsion. Spray dry the final emulsion to obtain fast-dissolving microcapsule-coated fat powder.

10. The method for preparing a fast-dissolving microencapsulated fat powder according to claim 9, characterized in that, The concentration of the sodium hydroxide solution is 1-3 mol / L, and the concentration of the hydrochloric acid solution is 1-3 mol / L.

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