Steady-state goat-based unsaturated fatty acid oil microcapsule powder and preparation method therefor

Abstract

Steady-state goat-based unsaturated fatty acid oil microcapsule powder and a preparation method therefor. The microcapsule powder comprises the following components in percentage by mass: 40.91%-92.5% of a wall material; 5%-50% of a core material treated by a special process; 2.5%-8% of an antioxidant; 0-0.99% of an emulsifier; and 0-0.1% of an acidity regulator, wherein the wall material comprises a protein and a carbohydrate. The protein is entirely derived from goat milk, and the carbohydrate is derived from goat milk or a plant; the core material has greatly enhanced stability after being treated by a special process; and a wall material from cow milk is avoided, thereby greatly improving the stability of the goat-based unsaturated fatty acid oil microcapsule powder, satisfying the quality requirements of goat infant formula milk powder manufacturers, and filling a technical gap.

Description

A kind of stabilized caprylic unsaturated fatty acid oil microcapsule powder and preparation method thereof Technical Field

[0001] The invention relates to the field of infant formula food and provides a stabilized caprylic unsaturated fatty acid oil microcapsule powder and a preparation method thereof. Background Art

[0002] Arachidonic acid (ARA) is a key polyunsaturated fatty acid that makes up the phospholipids in the cerebral cortex. It plays a vital role in the brain development of infants and young children. It is also an important and direct precursor for the synthesis of human prostaglandins and various physiologically active eicosapentaenoic acid derivatives. Along with linoleic acid and linolenic acid, it is considered one of the three essential fatty acids for the human body and possesses excellent nutritional value (Application and Research Progress of Arachidonic Acid, Zeng Siyu). ARA deficiency can limit the cognitive and intellectual development of infants and young children. Infants are also less able to synthesize ARA on their own. Therefore, ARA should be added to infant foods to ensure their healthy development.

[0003] Docosahexaenoic acid (DHA) is an essential ω-3 polyunsaturated fatty acid with benefits such as alleviating brain diseases, fighting inflammation, combating cancer, boosting immunity, enhancing lipid metabolism, and maintaining intestinal and cardiovascular health. DHA promotes brain and eye neurodevelopment and enhances early cognitive and motor development in infants. It is commonly used as an additive in infant formula and food. DHA derived from microalgae is widely used due to its simple structure and ease of absorption (Factors Influencing the Stability of Docosahexaenoic Acid Microalgae Oil Emulsions, Du Jian).

[0004] Breast milk fat provides over 50% of infant energy during development and plays a key role in the absorption of multiple vitamins and minerals. It is a nutritional indicator that requires particular attention in the design of infant formula. Infant formula is primarily formulated based on the fatty acid profile of breast milk. Therefore, appropriate supplementation of polyunsaturated fatty acids (such as linoleic acid and α-linolenic acid) is necessary to meet infant needs. Sunflower oil is a high-quality edible vegetable oil extracted from sunflower seeds through a process known as pressing. It is highly nutritious and rich in linoleic acid and oleic acid, reaching levels of 62.2% and 23.8%, respectively. It also contains sterols and various minerals, and is rich in tocopherols (approximately 74.3 mg / 100 g). α-tocopherol accounts for 96.7% of the total tocopherol content, or approximately 71.84 mg / 100 g (Research Progress on Volatile Flavor Compounds in Sunflower Oil, Yin Wenting). Sunflower oil has antioxidant, anti-cancer, and health benefits, as well as the prevention of various diseases.

[0005] DHA oil and ARA oil are both long-chain polyunsaturated fatty acids, which are easily oxidized. After oxidation, they will generate hydroperoxides, which will then break and decompose to produce a series of short carbon chain volatile and non-volatile substances, such as aldehydes, ketones, alcohols, acids, etc., which make the oil have a fishy smell and may cause damage to human health, thus affecting the application of DHA oil and ARA oil.

[0006] Microencapsulation technology uses polymer materials as wall materials to encapsulate core ingredients for protection. This technology can prolong and control the release of active substances within the microcapsules and is widely used in the fields of biology, food, pharmaceuticals, and cosmetics. Microencapsulation technology is currently a core method for slowing oil oxidation. Liquid oils are microencapsulated to form a solid powder with uniform particles. The oil enclosed in the wall material is isolated from pro-oxidant factors in the environment, effectively preventing oxidation problems, improving product stability and extending its shelf life. This ensures that the oil can be added and applied to food with stable quality. It also changes the product's appearance, making it easier to carry and transport, expanding its application range (Preparation and Oxidative Stability Study of Microencapsulated Powder of Schizochytrium oil, Lin Rongfang). Secondly, microencapsulation technology can mask the characteristic odor of oils to a certain extent, making the product more easily accepted by the market.

[0007] Goat milk is recognized worldwide as the closest dairy product to human breast milk. It contains no allergenic isocasein and is rich in adenosine triphosphate, which promotes the breakdown and utilization of lactose in the human intestine. Therefore, it is less likely to cause lactose intolerance. Compared to cow's milk, goat's milk offers higher nutritional value and is more easily absorbed by the human body, making it suitable for a variety of special populations. Currently, infant formulas on the market still mostly use cow's milk as a base. However, the extensive use of antibiotics in dairy farming to suppress mastitis has reduced the quality and nutritional value of cow's milk. Studies have shown that, among infants of the same delivery method and age, those fed goat's milk formula have a more diverse intestinal flora and a higher abundance of dominant bacteria (Effects of Goat's Milk Formula on Infant's Intestinal Microbiome and Major Beneficial Bacteria, Yang Li). Considering its nutritional and health benefits, goat's milk is the future trend for future infant formulas. Therefore, the development of oil microcapsule powders with goat's milk as the primary wall material is necessary to support the market development of goat's milk-based formulas.

[0008] There are already caprylic unsaturated fatty acid oil microcapsules on the market, but there are problems with the actual encapsulation effect and stability.

[0009] Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a stabilized sheep-based unsaturated fatty acid oil microcapsule powder and a preparation method thereof, which can improve the slightly insufficient stability of existing DHA and ARA sheep-based powder formulas on the market.

[0011] The above technical objectives of the present invention are achieved through the following technical solutions: A stabilized caprylic unsaturated fatty acid oil microcapsule powder comprises the following components in percentage by mass:

[0012] Wall material 40.91% ~ 92.5%;

[0013] Core material 5% to 50%;

[0014] Antioxidants 2.5% to 8%;

[0015] Emulsifier 0~0.99%;

[0016] Acidity regulator 0-0.1%;

[0017] The wall material includes sheep-derived protein and plant-derived carbohydrates;

[0018] The core material includes polyunsaturated fatty acid oil processed by a special process or polyunsaturated fatty acid oil blended with sunflower oil processed by a special process;

[0019] The antioxidants include water-phase antioxidants and oil-phase antioxidants;

[0020] The emulsifier includes a water phase emulsifier and an oil phase emulsifier.

[0021] The present invention is further configured as follows: the polyunsaturated fatty acid oil, i.e., the core material, is processed according to the following steps:

[0022] S1, catalytic ethyl esterification, adding alkali and ethanol to a polyunsaturated fatty acid glyceride having a content of 25% to 30%, wherein the mass ratio of ethanol to polyunsaturated fatty acid glyceride is 1.0 to 1.2, and catalytic ethyl esterification is performed at a reaction temperature of 65 to 70°C;

[0023] S2, molecular distillation, distillation temperature is 100 ~ 110 ℃;

[0024] S3, transesterification, adding lipase to the distilled polyunsaturated fatty acid glyceride, the transesterification temperature is 50-60°C;

[0025] S4, secondary molecular distillation, the distillation temperature is 215-255° C., to obtain unsaturated fatty acid glyceride with a content of 40-50%.

[0026] By adopting the above technical solution, the role of ethyl esterification is to convert polyunsaturated fatty acids with a content of 25-30% from triglyceride form (reacting with ethanol to obtain ethyl esters of different fatty acids) into ethyl ester form. The different fatty acids include unsaturated fatty acids and saturated fatty acids.

[0027] The purpose of the first molecular distillation is to remove some saturated fatty acid ethyl ester by-products and eliminate the oxidation products of unsaturated fatty acids.

[0028] Purpose of transesterification: Convert unsaturated fatty acid ethyl esters into unsaturated fatty acid glycerides.

[0029] The purpose of the second molecular distillation is to remove unsaturated fatty acid oxidation products and partially remove saturated fatty acid glycerides, resulting in a 40-45% unsaturated fatty acid glyceride content. Transesterification and a second molecular distillation can increase the polyunsaturated fatty acid glyceride content from 25-30% to over 40%. Polyunsaturated fatty acid glycerides with a content of over 50% are less stable than polyunsaturated fatty acid glycerides with a content of 40-45%. Pre-removal of polyunsaturated fatty acid oxidation products through the second molecular distillation reduces the removal load in the subsequent deodorization stage.

[0030] The present invention is further configured as follows: the unsaturated fatty acid glyceride with a content of 40-50% obtained in the step S4 is subjected to low-temperature short-time deodorization, the deodorization conditions being a temperature of 170° C., a time of 45-65 minutes, and a residual pressure of 230-235 Pa, and nitrogen is added to the deodorized polyunsaturated fatty acid glyceride, and a chelating agent and an oil-soluble antioxidant are added.

[0031] By adopting the above technical solution, the temperature and time required for heat treatment of unsaturated fatty acid glycerides in the deodorization process are shortened.

[0032] The present invention is further configured as follows: the chelating agent is citric acid.

[0033] By adopting the above technical solution, citric acid can chelate metal ions, slowing the oxidation rate and extending the shelf life of oils and fats. Unsaturated fatty acid oils and fats oxidize 100 to 1,000 times faster in the presence of high metal ion concentrations than in the absence or low metal ion concentrations.

[0034] The present invention is further configured as follows: the sheep-derived protein is one or a mixture of skimmed sheep milk powder, sheep concentrated whey protein, sheep isolated whey protein, sheep casein, and sheep desalted whey powder.

[0035] The present invention is further configured as follows: the plant-derived carbohydrate is selected from one or a mixture of two of maltodextrin, maltose, solid corn syrup, and goat lactose.

[0036] The present invention is further configured as follows: the core material is selected from one or a mixture of DHA oil, ARA oil, and sunflower oil.

[0037] The present invention is further configured as follows: the aqueous phase antioxidant is sodium ascorbate; the oil phase antioxidant is one or a mixture of two of ascorbyl palmitate, vitamin E, and phospholipids.

[0038] The present invention is further configured as follows: the aqueous phase emulsifier is one or a mixture of mono- and di-glycerol fatty acid esters and citric acid fatty acid glycerides; and the oil phase emulsifier is phospholipid.

[0039] The present invention is further configured as follows: the acidity regulator is one or a mixture of two of citric acid, sodium citrate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, and sodium dihydrogen phosphate.

[0040] A method for preparing stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 1, characterized in that the preparation method comprises the following steps:

[0041] (1) Preparation of aqueous phase: Weigh the wall material, aqueous antioxidant, aqueous emulsifier, and acidity regulator, dissolve them in 50-65°C pure water, and stir until completely mixed;

[0042] (2) Preparation of oil phase: Weigh the core material treated by a special process, thaw it in a water bath, mix the oil phase antioxidant, including the oil phase emulsifier, evenly, and shear it using a high-efficiency shearing machine for 1 to 30 minutes until the oil phase temperature rises by 1 to 5°C;

[0043] (3) pumping the oil phase prepared in step (2) into the water phase prepared in step (1), and pre-homogenizing using a high-speed shearing machine to disperse the oil phase in the water phase to form an emulsion;

[0044] (4) homogenizing the emulsion prepared in step (3) 1 to 2 times;

[0045] (5) pasteurizing or high-temperature instantaneous sterilization the emulsion after homogenization in step (4);

[0046] (6) spray-drying the liquid in step (5) to obtain the stabilized caprylic unsaturated fatty acid oil microcapsule powder.

[0047] The present invention is further configured as follows: in step (1), the weight of the pure water is 1 to 1.6 times the total weight of the microcapsule powder.

[0048] The present invention is further configured as follows: in step (4), the homogenization pressure is 25-45 MPa, and when the material is homogenized, the second homogenization pressure can be equal to or slightly lower than the first homogenization pressure.

[0049] The present invention is further configured as follows: in step (5), the pasteurization temperature is 60-70° C., the pasteurization time is 30-35 min or instantaneous sterilization is 80° C. for 15-30 s.

[0050] The present invention is further configured as follows: in step (6), the inlet air temperature used in the spray drying is 160-180°C, and the outlet air temperature is 70-90°C.

[0051] The beneficial effects of the present invention are:

[0052] 1. The protein in the present invention is all derived from goat milk, the carbohydrate is derived from plants, and there is no wall material derived from cow milk, which fully meets the requirements of infant goat milk formula milk powder.

[0053] 2. Compared with existing products on the market, the core material of the present invention has undergone a series of special process treatments, which greatly increases the amount of antioxidant added, especially the amount of sodium ascorbate added, and greatly reduces the amount of emulsifier, especially the aqueous phase emulsifier. By adding sunflower oil, the antioxidant property of ARA, especially DHA in the oil phase is improved. The actual embedding effect of the obtained microcapsules is excellent, and the shelf life stability of the product is greatly enhanced, which improves the current situation of the actual embedding effect and stability of sheep-based microcapsule oil powder being average, and fills the market gap in stabilized sheep-based unsaturated fatty acid microcapsule products.

[0054] 3. The wall material of the present invention is suitable for embedding DHA oil and ARA oil, and is also suitable for embedding one or more unsaturated fatty acid mixed oils. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0056] Example 1

[0057] In this embodiment, the method for preparing stabilized sheep-based ARA microcapsule powder includes the following steps:

[0058] (1) Preparation of aqueous phase: Weigh 41 kg of skimmed goat milk powder and 31.8 kg of maltodextrin as wall materials, 3 kg of sodium ascorbate as aqueous phase antioxidant, 0.1 kg of mono- and diglycerol fatty acid esters as aqueous phase emulsifier, and 10 g of sodium citrate as acidity regulator, dissolve them in 150 kg of pure water at 65°C, and stir until completely dissolved.

[0059] (2) Preparation of oil phase: Weigh 24 kg of ARA oil (core material) treated by a special process, 80 g of ascorbyl palmitate (oil phase antioxidant), 14.4 g of vitamin E, and 14.4 g of phospholipid (oil phase emulsifier) ​​and mix them evenly.

[0060] (3) adding the oil phase prepared in step (2) to the water phase prepared in step (1), and pre-homogenizing using a shearing machine to obtain an emulsion.

[0061] (4) The emulsion prepared in step (3) was homogenized twice using a homogenizer, with the first homogenization pressure being 35 MPa and the second homogenization pressure being 32 MPa.

[0062] (5) The material homogenized in step (4) is pasteurized at 68° C. for 30 min.

[0063] (6) The pasteurized material was spray-dried at an inlet air temperature of 168°C and an outlet air temperature of 82°C to obtain sheep-based ARA microcapsule powder.

[0064] Polyunsaturated fatty acid oils are treated with a special process, and the treatment method is carried out as follows:

[0065] S1, catalytic ethyl esterification, adding alkali and ethanol to a polyunsaturated fatty acid glyceride having a content of 25% to 30%, with a mass ratio of ethanol to polyunsaturated fatty acid glyceride being 1.2, and catalytic ethyl esterification is performed at a reaction temperature of 65 to 70°C;

[0066] S2, molecular distillation, distillation temperature is 100 ~ 110 ℃;

[0067] S3, transesterification, adding lipase to the distilled polyunsaturated fatty acid glyceride, the transesterification temperature is 50-60°C;

[0068] S4, secondary molecular distillation, the distillation temperature is 215-255° C., to obtain unsaturated fatty acid glyceride with a content of 40-50%.

[0069] The unsaturated fatty acid glyceride with a content of 40-50% obtained in step S4 is subjected to low-temperature short-time deodorization. The deodorization conditions are a temperature of 170° C., a time of 45-65 minutes, and a residual pressure of 230-235 Pa. The deodorized polyunsaturated fatty acid glyceride is nitrogen-filled and then citric acid and an oil-soluble antioxidant are added.

[0070] After testing, the surface oil was 0.21%, the peroxide value on the 46th day of the 60℃ destructive test was 1.5mmol / kg, and the anisidine value was 0.1.

[0071] Example 2

[0072] In this embodiment, the method for preparing stabilized sheep-based DHA microcapsule powder includes the following steps:

[0073] (1) Preparation of aqueous phase: Weigh 40.5 kg of skimmed goat milk powder and 28.9 kg of maltodextrin as wall materials, 4.3 kg of sodium ascorbate as aqueous phase antioxidant, 0.1 kg of mono- and diglycerol fatty acid esters as aqueous phase emulsifier, and 10 g of sodium citrate as acidity regulator, dissolve them in 150 kg of pure water at 65°C, and stir until completely dissolved.

[0074] (2) Preparation of oil phase: Weigh 24 kg of core material DHA oil treated by a special process, 2 kg of sunflower oil, 105.6 g of oil phase antioxidant ascorbyl palmitate, 19.2 g of vitamin E, and 36 g of oil phase emulsifier phospholipids, and mix them evenly.

[0075] (3) adding the oil phase prepared in step (2) to the water phase prepared in step (1), and pre-homogenizing using a shearing machine to obtain an emulsion.

[0076] (4) The emulsion prepared in step (3) was homogenized twice using a homogenizer, with the first homogenization pressure being 35 MPa and the second homogenization pressure being 32 MPa.

[0077] (5) The material homogenized in step (4) is pasteurized at 68° C. for 30 min.

[0078] (6) The pasteurized material was spray-dried at an inlet air temperature of 168°C and an outlet air temperature of 82°C to obtain sheep-based DHA microcapsule powder.

[0079] Polyunsaturated fatty acid oils are treated with a special process, and the treatment method is carried out as follows:

[0080] S1, catalytic ethyl esterification, adding alkali and ethanol to a polyunsaturated fatty acid glyceride having a content of 25% to 30%, with a mass ratio of ethanol to polyunsaturated fatty acid glyceride being 1.0, and catalytic ethyl esterification, the reaction temperature being 65 to 70°C;

[0081] S2, molecular distillation, distillation temperature is 100 ~ 110 ℃;

[0082] S3, transesterification, adding lipase to the distilled polyunsaturated fatty acid glyceride, the transesterification temperature is 50-60°C;

[0083] S4, secondary molecular distillation, the distillation temperature is 215-255° C., to obtain unsaturated fatty acid glyceride with a content of 40-50%.

[0084] The unsaturated fatty acid glyceride with a content of 40-50% obtained in step S4 is subjected to low-temperature short-time deodorization. The deodorization conditions are a temperature of 170° C., a time of 45-65 minutes, and a residual pressure of 230-235 Pa. The deodorized polyunsaturated fatty acid glyceride is nitrogen-filled and then citric acid and an oil-soluble antioxidant are added.

[0085] After testing, the surface oil was 0.14%, the peroxide value was 1.5mmol / kg and the anisidine value was 0.1 on the 46th day of the 60℃ destructive test.

[0086] Example 3

[0087] In this embodiment, the method for preparing stabilized ram-based ARA (or DHA) microcapsule powder includes the following steps:

[0088] (1) Preparation of aqueous phase: Weigh 19 kg of concentrated whey protein powder as the wall material and 50.9 kg of solid corn syrup, weigh 3.8 kg of sodium ascorbate as the aqueous phase antioxidant, weigh 0.1 kg of mono- and diglycerol fatty acid esters as the aqueous phase emulsifier, weigh 10 g of sodium citrate as the acidity regulator, dissolve them in 150 kg of pure water at 65°C, and stir until completely dissolved.

[0089] (2) Preparation of oil phase: Weigh 24 kg of core material ARA (or DHA) oil treated by a special process, 2 kg of sunflower oil, 105.6 g of oil phase antioxidant ascorbyl palmitate, 19.2 g of vitamin E, and 36 g of oil phase emulsifier phospholipids, and mix them evenly.

[0090] (3) adding the oil phase prepared in step (2) to the water phase prepared in step (1), and pre-homogenizing using a shearing machine to obtain an emulsion.

[0091] (4) The emulsion prepared in step (3) was homogenized twice using a homogenizer, with the first homogenization pressure being 33 MPa and the second homogenization pressure being 30 MPa.

[0092] (5) The material homogenized in step (4) is pasteurized at 68° C. for 30 min.

[0093] (6) The pasteurized material is spray-dried at an air inlet temperature of 168° C. and an air outlet temperature of 82° C. to obtain sheep-based ARA (or DHA) microcapsule powder.

[0094] Polyunsaturated fatty acid oils are treated with a special process, and the treatment method is carried out as follows:

[0095] S1, catalytic ethyl esterification, adding alkali and ethanol to a polyunsaturated fatty acid glyceride having a content of 25% to 30%, with a mass ratio of ethanol to polyunsaturated fatty acid glyceride being 1.2, and catalytic ethyl esterification is performed at a reaction temperature of 65 to 70°C;

[0096] S2, molecular distillation, distillation temperature is 100 ~ 110 ℃;

[0097] S3, transesterification, adding lipase to the distilled polyunsaturated fatty acid glyceride, the transesterification temperature is 50-60°C;

[0098] S4, secondary molecular distillation, the distillation temperature is 215-255° C., to obtain unsaturated fatty acid glyceride with a content of 40-50%.

[0099] The unsaturated fatty acid glyceride with a content of 40-50% obtained in step S4 is subjected to low-temperature short-time deodorization. The deodorization conditions are a temperature of 170° C., a time of 45-65 minutes, and a residual pressure of 230-235 Pa. The deodorized polyunsaturated fatty acid glyceride is nitrogen-filled and then citric acid and an oil-soluble antioxidant are added.

[0100] After testing, the surface oil was 0.12 or 0.10%, the peroxide value on the 46th day of the 60℃ destructive test was 1.79 or 2.04mmol / kg, and the anisidine value was 0.1.

[0101] Comparative Example 1

[0102] The preparation method of this comparative example is basically the same as that of Example 1, with the most critical difference being that in this comparative example, the main component of the oil phase used in step (2), i.e., the core material, has not been subjected to special processing.

[0103] The finished microcapsule powder thus obtained was tested to have a surface oil content of 0.17%, a peroxide value of 5.4 meq / kg, and an anisidine value of 3.2 after 46 days of a destructive test at 60°C (a peroxide value exceeding 5 meq / kg is considered unqualified, indicating that the product processed in Comparative Example 1 is not stable enough, and the anisidine value is 30 times higher than that in Example 1).

[0104] Comparative Example 2

[0105] The preparation method of this comparative example is basically the same as that of Example 2, with the most critical difference being that in this comparative example, the proportion of sodium ascorbate used in step (1) is only 0.5%.

[0106] The finished microcapsule powder thus obtained was tested to have a surface oil content of 0.21%, a peroxide value of 5.7 meq / kg after 46 days of destructive testing at 60°C, and an anisidine value of 1.1 (a peroxide value exceeding 5 meq / kg is considered unqualified, indicating that the product processed in Comparative Example 2 is not stable enough, and the anisidine value is 10 times higher than that in Example 2).

[0107] Comparative Example 3

[0108] The preparation method of this comparative example is basically the same as that of Example 3. The most critical difference is that in this comparative example, the main component of the oil phase used in step (2), i.e., the core material, has not been subjected to special process treatment and sunflower oil with good antioxidant properties is not added during the preparation of the oil phase in step (2) to further enhance the stability of the oil phase.

[0109] The finished microcapsule powder thus obtained was tested to have a surface oil content of 0.10% or 0.09%, a peroxide value of 5.2 or 5.4 meq / kg after 46 days of destructive testing at 60°C, and an anisidine value of 1.6 or 1.9 (a peroxide value exceeding 5 meq / kg is considered unqualified, indicating that the product processed in Comparative Example 3 is not stable enough, and the anisidine value is 10 times higher than that in Example 3).

[0110] There are many specific embodiments of the present invention, and the above description is only a preferred embodiment of the present invention. Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, further modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments listed here.

Claims

1. A stabilized caprylic unsaturated fatty acid oil microcapsule powder, characterized in that: Includes the following components in percentage by mass: Wall material 40.91% ~ 92.5%; Core material 5% to 50%; Antioxidants 2.5% to 8%; Emulsifier 0~0.99%; Acidity regulator 0~0.1%; The wall material includes sheep-derived protein and plant-derived carbohydrates; The core material includes processed polyunsaturated fatty acid oil or processed polyunsaturated fatty acid oil blended with sunflower seed oil; The antioxidants include water-phase antioxidants and oil-phase antioxidants; The emulsifier includes a water phase emulsifier and an oil phase emulsifier.

2. The stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 1, characterized in that: The polyunsaturated fatty acid oil, i.e. the core material, is processed according to the following steps: S1, catalytic ethyl esterification, adding alkali and ethanol to polyunsaturated fatty acid glyceride with a content of 25% to 30%, wherein the mass ratio of ethanol to polyunsaturated fatty acid glyceride is 1.0 to 1.2, and catalytic ethyl esterification is performed at a reaction temperature of 65 to 70°C; S2, molecular distillation, distillation temperature is 100 ~ 110 ℃; S3, transesterification, adding lipase to the distilled polyunsaturated fatty acid glyceride, the transesterification temperature is 50-60°C; S4, secondary molecular distillation, the distillation temperature is 215-255° C., to obtain unsaturated fatty acid glyceride with a content of 40-50%.

3. The stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 2, characterized in that: The unsaturated fatty acid glyceride with a content of 40-50% obtained in step S4 is subjected to low-temperature short-time deodorization, the deodorization conditions being a temperature of 170° C., a time of 45-65 min, and a residual pressure of 230-235 Pa. The deodorized polyunsaturated fatty acid glyceride is nitrogen-filled and then a chelating agent and an oil-soluble antioxidant are added.

4. The stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 3, characterized in that: The chelating agent is citric acid.

5. The stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 1, characterized in that: The sheep-derived protein is one or a mixture of skimmed sheep milk powder, sheep concentrated whey protein, sheep isolated whey protein, sheep casein, and sheep desalted whey powder.

6. The stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 1, characterized in that: The carbohydrates from plant sources are selected from one or a mixture of two of maltodextrin, maltose, solid corn syrup and goat lactose.

7. The stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 1, characterized in that: The core material is selected from one or a mixture of DHA oil, ARA oil, and sunflower oil.

8. The stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 1, characterized in that: The water phase antioxidant is sodium ascorbate; the oil phase antioxidant is one or a mixture of two of ascorbyl palmitate, vitamin E and phospholipids.

9. The stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 1, characterized in that: The water phase emulsifier is one of mono- and di-glycerol fatty acid esters and citric acid fatty acid glyceride or a mixture of two thereof; the oil phase emulsifier is phospholipid.

10. The stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 1, characterized in that: The acidity regulator is one of citric acid, sodium citrate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, or a mixture of two thereof.

11. A method for preparing stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 1, characterized in that: The preparation method comprises the following steps: (1) Preparation of aqueous phase: Weigh the wall material, aqueous antioxidant, aqueous emulsifier, and acidity regulator, dissolve them in 50-65°C pure water, and stir until completely mixed; (2) Preparation of oil phase: weigh the core material, thaw it in a water bath, mix the oil phase antioxidant, including the oil phase emulsifier, evenly, and use a high-efficiency shearing machine to shear for 1 to 30 minutes until the oil phase temperature rises by 1 to 5°C; (3) pumping the oil phase prepared in step (2) into the water phase prepared in step (1), and pre-homogenizing using a high-speed shearing machine to disperse the oil phase in the water phase to form an emulsion; (4) homogenizing the emulsion prepared in step (3) 1 to 2 times; (5) pasteurizing or high-temperature instantaneous sterilizing the emulsion after homogenization in step (4); (6) spray drying the liquid in step (5) to obtain the stabilized caprylic unsaturated fatty acid oil microcapsule powder.

12. The method for preparing stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 10, characterized in that: In step (1), the weight of the pure water is 1 to 1.6 times the total weight of the microcapsule powder.

13. The method for preparing stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 10, characterized in that: In step (4), the homogenization pressure is 25-45 MPa. When the material is homogenized, the second homogenization pressure can be equal to or slightly lower than the first homogenization pressure.

14. The method for preparing stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 10, characterized in that: In step (5), the pasteurization temperature is 60-70° C., and the pasteurization time is 30-35 min or 80° C., 15-30 s instantaneous sterilization.

15. The method for preparing stabilized caprylic unsaturated fatty acid oil microcapsule powder according to claim 10, characterized in that: In step (6), the inlet air temperature used in the spray drying is 160-180°C, and the outlet air temperature is 70-90°C.