Nutritional emulsion and preparation method thereof

Abstract

The invention provides a nutritional emulsion and a preparation method thereof. Specifically, the nutritional emulsion comprises egg yolk phospholipid, OPO-containing triglyceride, raw material oil and water, and the weight ratio of the egg yolk phospholipid to the OPO-containing triglyceride ranges from 1: 40 to 3: 7; the average particle size D [4, 3] of oil drop particles formed in the nutritional emulsion is in the range of 0.8-1.5 [mu] m; and in the OPO-containing triglyceride, the proportion of 2-position palmitic acid in total palmitic acid is at least 52%, and the content of OPO is at least 40% by weight. The nutritional emulsion provided by the invention has good system stability, and does not have a turbid or layering phenomenon after being placed for a long time.

Description

Technical Field

[0001] This invention relates to the field of food processing technology. Specifically, this invention provides a nutritional emulsion containing egg yolk phospholipids and 1,3-dioleoyl-2-palmitoylglycerol triglyceride (OPO) and its preparation method. Background Technology

[0002] Egg yolk phospholipids, also known as lecithin, are a natural mixture of phospholipids found in egg yolks. They possess amphiphilic properties, meaning one end is hydrophilic (containing a nitrogen or phosphorus head), while the other end is hydrophobic (a long, lipophilic hydrocarbon chain). Egg yolk phospholipids have important physiological functions and applications in edible oils. Specifically, they exhibit antioxidant, antibacterial, anti-inflammatory, and neuroprotective and cardiovascular activities. They can improve lipid metabolism, protect the retina, and enhance brain function. Furthermore, egg yolk lecithin can alleviate blood clotting, clarify blood lipids, and prevent arteriosclerosis, myocardial infarction, and cerebral hemorrhage. Choline in egg yolk lecithin is a precursor to the neurotransmitter acetylcholine, which can improve memory and learning abilities. Additionally, egg yolk lecithin can promote the synthesis and regeneration of lipoproteins, improve alcoholic liver disorders, and protect the membranes of liver mitochondria, microsomes, and lysosomes from damage. In conclusion, due to its multifunctionality and wide application in the food industry, egg yolk phospholipids are considered a high-value natural resource. In cooking oil, it not only enhances the nutritional value of food, but also improves its flavor and texture, which is of great significance for promoting health and improving food quality.

[0003] On the other hand, 1,3-dioleoyl-2-palmitoylglycerol (OPO) is a structured fat characterized by palmitic acid primarily located at the sn-2 position of the triglyceride, while unsaturated fatty acids such as oleic acid are mainly located at the sn-1 and sn-3 positions. This structure is similar to the natural fat structure in breast milk. OPO structured lipids offer a variety of unique nutritional and health benefits, such as preventing constipation, optimizing calcium and fatty acid absorption, enhancing bone development, and promoting the growth of beneficial bacteria. The addition of OPO structured lipids is considered one of the latest advancements in nutritional foods. By mimicking the fat structure of breast milk, it helps to better meet the natural nutritional needs of babies and support their healthy growth. In conclusion, 1,3-dioleoyl-2-palmitoylglycerol (OPO) has become an important food ingredient due to its similarity to the fat structure of breast milk and its various health benefits in infant formula.

[0004] In view of this, developing nutritional foods that contain both egg yolk phospholipids and OPO is a current trend in the food processing industry.

[0005] Currently, emulsion systems containing both egg yolk phospholipids and OPO are a hot topic in the development of nutritional foods. However, existing OPO nutritional oil emulsions suffer from stability issues. Specifically, emulsion systems containing OPO generally exhibit poor stability, quickly showing precipitation and stratification after preparation.

[0006] Therefore, it is of great significance to develop a nutritional emulsion that contains egg yolk phospholipids and OPO while having good system stability. Summary of the Invention

[0007] Based on the technical problems described above, the objective of this invention is to provide a nutritional emulsion and its preparation method, wherein the nutritional emulsion simultaneously contains egg yolk phospholipids and OPO. The nutritional emulsion according to the invention exhibits good system stability and will not become cloudy or separate after long-term storage.

[0008] The inventor completed this invention through in-depth and meticulous research.

[0009] Specifically, in one aspect, the present invention provides a nutritional emulsion comprising egg yolk lecithin, OPO-containing triglycerides, raw material oil, and water, wherein:

[0010] The weight ratio of the egg yolk phospholipids to the OPO-containing triglycerides is in the range of 1:40 to 3:7;

[0011] The average particle size D of the oil droplets formed in the nutritional emulsion [4，3] Within the range of 0.8-1.5 μm; and

[0012] In the OPO-containing triglycerides, the 2-palmitic acid accounts for at least 52% of the total palmitic acid, and the OPO content is at least 40% by weight.

[0013] In another aspect, the present invention provides a method for preparing a nutritional emulsion comprising egg yolk lecithin, OPO-containing triglycerides, raw material oil, and water, the method comprising the following steps:

[0014] (1) The egg yolk phospholipids, the OPO-containing triglycerides, the raw material oil, and water are mixed to obtain a dispersion: and

[0015] (2) The dispersion is subjected to shearing and homogenization processes in sequence, wherein the shearing process includes shearing the dispersion at a rotation speed of 3000-5000 rpm under heating, and the homogenization process includes homogenizing the sheared dispersion under a pressure of 300-400 bar under heating.

[0016] Compared with the prior art in this field, the advantages of the present invention are as follows:

[0017] 1. Improved system stability: By controlling the composition and preparation process of the nutritional emulsion, this invention significantly improves the stability of OPO nutritional oil emulsion containing egg yolk phospholipids, and solves the problem of emulsion stratification in the prior art.

[0018] 2. No need to add solubilizer: Compared with the prior art, the improved emulsion stability of the present invention does not rely on the addition of solubilizers (e.g., hydroxypropyl β-cyclodextrin, etc.), which makes the present invention applicable to a wider range of oil and fat mixture systems, especially those systems that do not contain solubilizers (e.g., hydroxypropyl β-cyclodextrin, etc.).

[0019] 3. Optimized processing technology: This invention employs specific high-speed shearing and high-pressure homogenization steps, which are carried out under specific temperature and pressure conditions to ensure the uniformity and stability of the emulsion.

[0020] 4. Expanded application scope: Due to the improved emulsion stability provided by this invention, OPO nutritional emulsions containing egg yolk phospholipids are more easily applied to water-soluble products, thus expanding their application scope in the food processing field. Detailed Implementation

[0021] It should be understood that, without departing from the scope or spirit of this disclosure, those skilled in the art can conceive of various other embodiments and can modify them based on the teachings of this specification. Therefore, the following specific embodiments are not intended to be limiting.

[0022] Unless otherwise specified, all figures used in this specification and claims to indicate feature dimensions, quantities, and physical properties should be understood to be modified by the term "about" in all cases. Therefore, unless stated to the contrary, the numerical parameters listed in the foregoing specification and appended claims are approximations, and those skilled in the art can appropriately modify these approximations to obtain the desired characteristics using the teachings disclosed herein. The use of numerical ranges indicated by endpoints includes all numbers within that range and any range within that range; for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, etc.

[0023] As mentioned earlier, emulsion systems containing both egg yolk phospholipids and OPO are currently a hot topic in the development of nutritional foods. However, existing OPO nutritional oil emulsions suffer from stability issues. Specifically, emulsion systems containing OPO generally exhibit poor stability, quickly showing precipitation and stratification after preparation.

[0024] The inventors of this invention, through systematic research, discovered that by controlling the specific types and contents of each component in the emulsion (e.g., the weight ratio of egg yolk phospholipids to OPO-containing triglycerides) and combining it with a specific dispersion process (including high-speed shearing and high-pressure homogenization under specific conditions), a nutritional emulsion containing both egg yolk phospholipids and 1,3-dioleoyl-2-palmitoyl triglycerides (OPO) can be obtained while maintaining good system stability. Unbound by theory, it is speculated that, according to the technical solution of this invention, the synergistic effect of egg yolk phospholipids as an emulsifier with OPO (1,3-dioleoyl-2-palmitoyl triglycerides) forms emulsion particles with excellent stability and uniformity. This synergistic effect not only enhances the physical properties of the emulsion but also significantly improves its nutritional value. Specifically, egg yolk phospholipids, with their unique amphiphilic properties, can effectively reduce the tension at the oil-water interface and promote the uniform dispersion of oil droplets. Furthermore, the addition of OPO not only helps to form well-dispersed oil droplets but also, through its unique structure, promotes the efficient absorption of fatty acids by the human body. According to the technical solution of the present invention, by controlling the specific type and content of each component (e.g., the weight ratio of the egg yolk phospholipid to the OPO-containing triglyceride) and combining it with a specific dispersion process (including high-speed shearing and high-pressure homogenization under specific conditions), oil droplet particles of a specific size can be formed in the nutrient emulsion, with an average particle size D. [4，3] The particle size was controlled within the range of 0.8–1.5 μm. The average particle size D within this size range... [4，3] Control not only ensures the homogeneity of the emulsion system but also improves its stability, thereby extending the product's shelf life and guaranteeing the consistency and reliability of the emulsion during application.

[0025] Specifically, according to one aspect of the present invention, a nutritional emulsion is provided, the nutritional emulsion comprising egg yolk lecithin, OPO-containing triglycerides, raw material oil, and water, wherein:

[0026] The weight ratio of the egg yolk phospholipids to the OPO-containing triglycerides is in the range of 1:40 to 3:7;

[0027] The average particle size D of the oil droplets formed in the nutritional emulsion [4，3 Within the range of 0.8-1.5 μm; and

[0028] In the OPO-containing triglycerides, the 2-palmitic acid accounts for at least 52% of the total palmitic acid, and the OPO content is at least 40% by weight.

[0029] In this application, unless otherwise specified, the "average particle size D" of the oil droplets formed in the nutritional emulsion according to the present invention is... [4，3]"Average particle size D" is a statistical parameter used to describe the particle size distribution of the dispersed phase in an emulsion, and it has similar characteristics to the existing definition of "average particle size D". [4，3] The same concept applies to oil droplets. This parameter is a weighted average particle size based on volume and surface area, also known as the De Brouckere mean, which represents the ratio of the volume of all particles in the emulsion to the total surface area. The "average particle size D" of oil droplets... [4，3] "It can usually be measured by a particle size analyzer, such as laser diffraction or dynamic light scattering."

[0030] It should be noted that the average particle size D of the oil droplets formed in the nutritional emulsion is... [4，3] It has a significant impact on the stability and appearance properties of the emulsion. When the average particle size D of the oil droplets... [4，3] When the particle size is less than 0.8 μm, the resulting nutrient emulsion is prone to turbidity or stratification. Unbound by theory, it is speculated that smaller oil droplets (average particle size D...)... [4，3] A particle size smaller than 0.8 μm implies a larger total surface area, which leads to increased tension at the oil-water interface. Since the emulsifier is insufficient to cover these interfaces, the stability of the emulsion decreases, and oil droplets may aggregate, resulting in turbidity or stratification. On the other hand, when the average particle size D of the oil droplets... [4，3] When the droplet size is greater than 1.5 μm, the resulting nutrient emulsion will also exhibit turbidity or stratification. Without being bound by theory, it is speculated that larger oil droplets, due to their greater mass and volume, are more significantly affected by gravity, leading to faster settling rates. This may cause emulsion stratification. Furthermore, the increased size of the oil droplets enhances the van der Waals forces between particles. This attraction may cause the oil droplets to aggregate, forming larger clumps, which in turn leads to emulsion turbidity or stratification.

[0031] Preferably, to further improve the system stability of the prepared nutrient emulsion, the particle size D of the oil droplets formed in the nutrient emulsion is... 50 Less than 1.5μm.

[0032] In this application, unless otherwise specified, the particle size D of the oil droplets formed in the nutritional emulsion according to the present invention is... 50 It has the same characteristics as the existing technology regarding "particle size D" 50 The same concept as "particle size D". 50 Also known as median particle size or volume median diameter, it is an important parameter describing the particle size distribution in an emulsion. It indicates that in the emulsion, 50% of the particles are smaller than this diameter, while the other 50% are larger. The "particle size D" of oil droplets... 50 "It can usually be measured by a particle size analyzer, such as laser diffraction or dynamic light scattering."

[0033] Preferably, to further improve the system stability of the prepared nutrient emulsion, the particle size D of the oil droplets formed in the nutrient emulsion is... 90 Less than 2.5μm.

[0034] In this application, unless otherwise specified, the particle size D of the oil droplets formed in the nutritional emulsion according to the present invention is... 90 It has the same characteristics as the existing technology regarding "particle size D" 90 The same concept as "particle size D". 90 Also known as the 90th percentile particle size distribution, it is a key parameter describing the particle size distribution in an emulsion. It indicates that 90% of the particles in the emulsion are smaller than this size, while the remaining 10% are larger. The particle size D of oil droplets... 90 "It can usually be measured by a particle size analyzer, such as laser diffraction or dynamic light scattering."

[0035] According to the technical solution of the present invention, the weight ratio of the egg yolk phospholipid to the OPO-containing triglyceride is in the range of 1:40 to 3:7. When the weight ratio of the egg yolk phospholipid to the OPO-containing triglyceride is less than 1:40, the amount of egg yolk phospholipid as an emulsifier is too small, which cannot completely stabilize the oil phase system containing OPO, resulting in stratification and failure to form an average particle size D of oil droplets. [4，3] Nutrient emulsions in the range of 0.8-1.5 μm. On the other hand, when the weight ratio of egg yolk phospholipids to the OPO-containing triglycerides is greater than 3:7, the excessive amount of egg yolk phospholipids as emulsifier may exceed the requirements of the oil-water interface, causing the emulsifier to form a multilayer coating on the oil droplet surface, thereby increasing the size of the oil droplets and failing to form an average particle size D of oil droplets. [4，3 Nutrient emulsions in the range of 0.8-1.5 μm. Furthermore, the efficiency of emulsifiers may decrease with increasing concentration; excessive emulsifiers do not proportionally increase emulsion stability and may instead lead to larger emulsion particles. As a negative consequence, the emulsion may separate into layers after prolonged storage.

[0036] According to the technical solution of the present invention, in order to form oil droplet particles of the desired particle size range in the nutritional emulsion to obtain a nutritional emulsion with good system stability, the weight ratio of the egg yolk phospholipid to the OPO-containing triglyceride is preferably in the range of 1:40 to 1:3, more preferably 1:20 to 1:15.

[0037] To achieve a good combination of egg yolk phospholipids and OPO, the sum of the weight of the egg yolk phospholipids and the OPO-containing triglycerides accounts for 8-30%, preferably 8-20%, and more preferably 8-10% of the total weight of the nutritional emulsion.

[0038] Preferably, in order to better form oil droplet particles with the desired average particle size, the water accounts for more than 80% of the total weight of the nutrient emulsion, more preferably 80-90%.

[0039] Preferably, in order to better form oil droplet particles with the desired average particle size, the sum of the weights of the egg yolk phospholipids, the OPO-containing triglycerides, and the raw material oil accounts for 10-20% of the total weight of the nutritional emulsion.

[0040] The nutritional emulsion according to the present invention, in addition to egg yolk phospholipids and OPO-containing triglycerides, also contains raw material oil. This raw material oil not only improves the nutrient composition distribution of the nutritional emulsion but also enhances the system stability. There are no particular limitations on the specific type of raw material oil that can be used in this invention. Preferably, the raw material oil is selected from one or more of vegetable oils or animal oils. More preferably, the raw material oil is selected from one or more of the following groups: sunflower seed oil (including high-oleic sunflower seed oil), medium-chain triglycerides, coconut oil, flaxseed oil, anhydrous butter, palm kernel oil, DHA algal oil, fish oil, walnut oil, camellia oil, perilla seed oil, sea buckthorn seed oil, avocado oil, wheat germ oil, blackcurrant seed oil, borage oil, eucommia seed oil, evening primrose oil, soybean oil, rapeseed oil (including low-erucic acid rapeseed oil), corn oil, peanut oil, safflower seed oil, palm oil, rice bran oil, sesame oil, γ-linolenic acid oil, tomato seed oil, peony seed oil, krill oil, maple seed oil, sacha inchi oil, milk thistle seed oil, conjugated linoleic acid, and shea butter, etc. More preferably, the sunflower seed oil is high-oleic sunflower seed oil (HOSO). Preferably, the sunflower seed oil is high-oleic sunflower seed oil.

[0041] According to certain embodiments of the present invention, the water used to form the nutritional emulsion of the present invention is preferably purified water. Purified water removes ionic impurities such as calcium, magnesium, and sodium, reducing the number of ions that may react with emulsifiers or other components, thereby avoiding potential interference from these ions on the stability and emulsification effect of the emulsion. The presence of ions may affect the adsorption and arrangement of emulsifiers at the oil-water interface; using purified water helps maintain the stability of the emulsifiers, thereby improving the overall stability of the emulsion. Ionic impurities in the nutritional emulsion may affect the shelf life and quality of the product; using purified water ensures product quality and avoids product deterioration or changes in taste caused by ions. More preferably, the water used to form the nutritional emulsion of the present invention is preferably deionized water.

[0042] Preferably, the nutritional emulsion according to the invention may contain phospholipid-bound arachidonic acid (ARA) and phospholipid-bound docosahexaenoic acid (DHA). For example, the nutritional emulsion according to the invention may contain 0.016 to 0.064 g / 100 g, preferably 0.032 to 0.064 g / 100 g, such as 0.032 to 0.06 g / 100 g of phospholipid-bound ARA, and / or the nutritional emulsion according to the invention may contain 0.008 to 0.032 g / 100 g, preferably 0.016 to 0.032 g / 100 g, such as 0.02 to 0.03 g / 100 g of phospholipid-bound DHA.

[0043] There are no particular limitations on the egg yolk phospholipids that can be used in this invention, and they can be obtained through conventional commercial means. Preferably, the egg yolk phospholipids are egg yolk phospholipids with a phospholipid content of ≥75%. The egg yolk phospholipids contain phosphatidylcholine (PC), phosphatidylethanolamine (PE), sphingomyelin (SM), and lysophospholipids (LPC+LPE), etc.

[0044] Preferably, the egg yolk phospholipids comprise 55-82% by weight phosphatidylcholine (PC), 11-20% by weight phosphatidylethanolamine (PE), 2-4% by weight sphingomyelin (SM), and 2-9% by weight lysophospholipids, wherein the lysophospholipids comprise lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE). Preferably, the egg yolk phospholipids also comprise 1-3% by weight docosahexaenoic acid (DHA) and 2-4% by weight arachidonic acid (ARA).

[0045] Alternatively, a specific example of egg yolk lecithin includes ELIP 3020 from AAK, a blend of egg yolk lecithin and high-oleic sunflower oil in a mass ratio of approximately 1:1. ELIP 3020 contains phospholipid-bound DHA and phospholipid-bound ARA, among other things.

[0046] There are no particular limitations on the OPO-containing triglycerides that can be used in this invention; they can be obtained through conventional commercial routes or synthesized via traditional esterification reactions. Esterification is the process by which glycerol reacts with fatty acids in the presence of an acidic or basic catalyst to form triglycerides. In addition to esterification, transesterification can also be used to prepare OPO-structured esters. Transesterification involves existing triglycerides and free fatty acids, adjusting the position of the fatty acids on the triglyceride molecule in the presence of a specific catalyst (usually an enzyme). The choice of catalyst is crucial in both esterification and transesterification reactions. Esterification can be carried out using acidic or basic catalysts, while transesterification typically requires a more specific enzymatic catalyst.

[0047] Preferably, the OPO-containing triglycerides that can be used in this invention are fractions of transesterification products obtained by selective transesterification of vegetable oil (e.g., palm oil) and oleic acid at the 1,3-position. Preferably, in the OPO-containing triglycerides that can be used in this invention, the proportion of 2-palmitic acid in the total palmitic acid is at least 52%, and the OPO content is at least 40% by weight. The OPO-containing triglycerides are commercially available as food fortifiers. The physicochemical properties of the OPO-containing triglycerides meet the requirements specified in the Chinese National Food Safety Standard GB 30604-2015. Specifically, the OPO-containing triglycerides that can be used in this invention are 1,3-dioleoyl-2-palmitoyl triglycerides (product name: INFAT C250) produced by Ahuskars Oils (Zhangjiagang) Co., Ltd.

[0048] In addition to the components mentioned above, one or more additives conventionally used in the field of nutritional emulsions may be added to the method according to the present invention for preparing a nutritional emulsion containing egg yolk phospholipids and 1,3-dioleoyl-2-palmitoylglycerol triglyceride, as long as they do not affect the formation of an average particle size D in the mixture of egg yolk phospholipids, OPO-containing triglyceride, raw material oil and water. [4，3] Oil droplet particles in the range of 0.8-1.5 μm are acceptable. Specific examples of one or more applicable additives include: antioxidants, including but not limited to vitamin E (mixed tocopherols), AP (ascorbyl palmitate), BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), etc.; emulsifiers, including but not limited to caprylic / capric triglycerides, etc.; nutritional fortifiers, including but not limited to vitamin A, vitamin D, DHA (docosahexaenoic acid), EPA (eicosapentaenoic acid), etc.; stabilizers, including but not limited to EDTA, etc.; preservatives, including but not limited to nisin, etc.; and functional ingredients, including but not limited to oligosaccharides, etc.

[0049] According to another aspect of the present invention, a method for preparing the above-described nutritional emulsion is provided, the method comprising the following steps:

[0050] (1) The egg yolk phospholipids, the OPO-containing triglycerides, the raw material oil, and water are mixed to obtain a dispersion; and

[0051] (2) The dispersion is subjected to shearing and homogenization processes in sequence, wherein the shearing process includes shearing the dispersion at a rotation speed of 3000-5000 rpm under heating, and the homogenization process includes homogenizing the sheared dispersion under a pressure of 300-400 bar under heating.

[0052] The inventors of this invention discovered in their research that by controlling the specific types and contents of each component in the emulsion and, in particular, employing specific dispersion processing techniques (including high-speed shearing and high-pressure homogenization under specific conditions), a nutritional emulsion containing egg yolk phospholipids and 1,3-dioleoyl-2-palmitoylglycerol (OPO) can be obtained while exhibiting good system stability.

[0053] The inventors of this invention have discovered that specific dispersion processes (including high-speed shearing and high-pressure homogenization under specific conditions) are crucial for obtaining nutritional emulsions containing egg yolk phospholipids and OPO with good stability. Without being bound by theory, it is hypothesized that high-speed shearing and high-pressure homogenization can significantly improve emulsification, resulting in more uniform oil droplet dispersion and the formation of finer oil droplet particles, which contributes to improved emulsion stability. Furthermore, by specifically selecting the process conditions for high-speed shearing and high-pressure homogenization, the tension at the oil-water interface can be reduced physically, making it easier for oil droplets to disperse in water and promoting the formation of oil-in-water (W / O) emulsions. Egg yolk phospholipids, as an emulsifier, can be more evenly distributed at the oil-water interface under the action of high-speed shearing and high-pressure homogenization, thus improving their emulsification efficiency.

[0054] Specifically, in the shearing process of step (2) of the method according to the invention, emulsification and dispersion are achieved by applying shear force. There are no particular limitations on the specific type of apparatus used for the shearing process; common shearing apparatuses used in conventional oil and fat processing can be selected. Preferably, high-speed shear tanks, high-shear emulsifiers, colloid mills, or homogenizers can be used.

[0055] According to certain embodiments of the present invention, in step (2), the shearing process includes shearing the dispersion at a rotation speed of 3000-5000 rpm under heating. When the rotation speed used for shearing is less than 3000 rpm, a small amount of precipitation exists in the resulting egg yolk phospholipid-OPO emulsion system, and stratification occurs after a long period of standing. On the other hand, when the rotation speed used for shearing is greater than 5000 rpm, a small amount of precipitation also appears in the resulting egg yolk phospholipid-OPO emulsion system. It is speculated that this is because the excessively high shear rate causes the oil droplets in the emulsion system to be subjected to excessive shearing action, thereby destroying the stability of the oil droplets, causing the oil droplets to aggregate or merge, forming larger particles, and eventually precipitating.

[0056] According to certain embodiments of the present invention, the shearing process is carried out under heating conditions. Preferably, in step (2), in order to improve the emulsification effect of egg yolk phospholipids, OPO-containing triglycerides, raw material oil, and water, the shearing process is carried out in a temperature range of 55°C-70°C. Preferably, in step (2), in order to improve the emulsification effect of egg yolk phospholipids, OPO-containing triglycerides, raw material oil, and water, the shearing process is carried out for 3-5 minutes.

[0057] Specifically, in the homogenization process of step (2) of the method according to the invention, large droplets in the oil are broken into smaller droplets by applying high shear force, thereby reducing the average size of the droplets in the emulsion. There are no particular limitations on the specific type of apparatus used for homogenization; common homogenizing apparatuses used in conventional oil and fat food processing can be selected. Preferably, a high-pressure homogenizer or the like can be used.

[0058] According to certain embodiments of the present invention, in step (2), the homogenization process includes homogenizing the sheared dispersion under heating at a pressure of 300-400 bar. When the pressure used for homogenization is less than 300 bar, a large amount of precipitation quickly appears in the resulting egg yolk phospholipid-OPO emulsion system, resulting in stratification; when the pressure used for homogenization is greater than 400 bar, a small amount of precipitation also appears in the resulting egg yolk phospholipid-OPO emulsion system (and even a large amount of precipitation in the case of certain formulations), and the egg yolk phospholipid cannot be completely dispersed. Without being bound by theory, it is speculated that when the pressure of high-pressure homogenization is too high, it will cause the oil droplets to become excessively fine, and may even destroy the oil droplet structure, causing the oil droplets to aggregate or merge, forming larger particles and precipitating.

[0059] According to certain embodiments of the present invention, the homogenization process is carried out under heating conditions. Preferably, in step (2), in order to improve the emulsification effect of egg yolk phospholipids, OPO-containing triglycerides, raw material oil, and water, the homogenization process is carried out in a temperature range of 55°C-70°C. Preferably, in step (2), in order to improve the emulsification effect of egg yolk phospholipids, OPO-containing triglycerides, raw material oil, and water, the homogenization process is carried out for 5-10 minutes.

[0060] According to certain embodiments of the present invention, in order to further improve the miscibility of egg yolk phospholipids and OPO-containing triglycerides, in step (1), egg yolk phospholipids and raw material oil can be mixed first to obtain a premix, and then the premix can be mixed with the OPO-containing triglycerides and water to obtain the dispersion for step (2). Preferably, the raw material oil comprises sunflower seed oil. More preferably, in order to further improve the emulsifying effect of egg yolk phospholipids, OPO-containing triglycerides, raw material oil and water, the raw material oil comprises high-oleic sunflower seed oil.

[0061] The following detailed description is intended to illustrate the contents of this disclosure by way of example and not by way of limitation.

[0062] Specific embodiment 1 is a nutritional emulsion, wherein the nutritional emulsion comprises egg yolk phospholipids, OPO-containing triglycerides, raw material oil, and water, wherein:

[0063] The weight ratio of the egg yolk phospholipids to the OPO-containing triglycerides is in the range of 1:40 to 3:7;

[0064] The average particle size D of the oil droplets formed in the nutritional emulsion [4,3] Within the range of 0.8-1.5 μm; and

[0065] In the OPO-containing triglycerides, the 2-palmitic acid accounts for at least 52% of the total palmitic acid, and the OPO content is at least 40% by weight.

[0066] Specific embodiment 2 is based on the nutritional emulsion described in specific embodiment 1, wherein the particle size D of the oil droplets formed in the nutritional emulsion is... 50 Less than 1.5μm.

[0067] Specific embodiment 3 is based on the nutritional emulsion described in specific embodiment 1, wherein the particle size D of the oil droplets formed in the nutritional emulsion is... 90 Less than 2.5μm.

[0068] Specific embodiment 4 is a nutritional emulsion according to specific embodiment 1, wherein the weight ratio of egg yolk phospholipids to OPO-containing triglycerides is in the range of 1:40 to 1:3.

[0069] Specific embodiment 5 is a nutritional emulsion according to specific embodiment 1, wherein the weight ratio of egg yolk phospholipids to the OPO-containing triglycerides is in the range of 1:20 to 1:15.

[0070] Specific embodiment 6 is a nutritional emulsion according to specific embodiment 1, wherein the sum of the weight of the egg yolk phospholipid and the OPO-containing triglyceride accounts for 8-30% of the total weight of the nutritional emulsion.

[0071] Specific embodiment 7 is a nutritional emulsion according to specific embodiment 1, wherein the sum of the weight of the egg yolk phospholipid and the OPO-containing triglyceride accounts for 8-20% of the total weight of the nutritional emulsion.

[0072] Specific embodiment 8 is a nutritional emulsion according to specific embodiment 1, wherein the weight of water accounts for more than 80% of the total weight of the nutritional emulsion.

[0073] Specific embodiment 9 is a nutritional emulsion according to specific embodiment 1, wherein the weight of water accounts for 80-90% of the total weight of the nutritional emulsion.

[0074] Specific embodiment 10 is a nutritional emulsion according to specific embodiment 1, wherein the sum of the weights of the egg yolk phospholipids, the OPO-containing triglycerides, and the raw material oil accounts for 10-20% of the total weight of the nutritional emulsion.

[0075] Specific embodiment 11 is a nutritional emulsion according to specific embodiment 1, wherein the OPO is 1,3-dioleoyl-2-palmitoylglycerol triglyceride.

[0076] Specific embodiment 12 is a nutritional emulsion according to specific embodiment 1, wherein the egg yolk phospholipids contain 55-82% by weight of phosphatidylcholine (PC), 11-20% by weight of phosphatidylethanolamine (PE), 2-4% by weight of sphingomyelin (SM) and 2-9% by weight of lysophospholipids, wherein the lysophospholipids contain lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE).

[0077] Specific embodiment 13 is a nutritional emulsion according to specific embodiment 12, wherein the egg yolk phospholipids further contain 1-3% by weight of DHA and 2-4% by weight of ARA.

[0078] Specific embodiment 14 is a nutritional emulsion according to specific embodiment 1, wherein the raw material oil is selected from one or more of vegetable oil or animal oil.

[0079] Specific embodiment 15 is a nutritional emulsion according to specific embodiment 1, wherein the raw material oil is selected from one or more of the following groups: sunflower seed oil, medium-chain triglycerides, coconut oil, flaxseed oil, anhydrous butter, palm kernel oil, DHA algal oil, fish oil, walnut oil, camellia oil, perilla seed oil, sea buckthorn seed oil, avocado oil, wheat germ oil, blackcurrant seed oil, borage oil, eucommia seed oil, evening primrose oil, soybean oil, rapeseed oil, corn oil, peanut oil, safflower seed oil, palm oil, rice bran oil, sesame oil, γ-linolenic acid oil, tomato seed oil, peony seed oil, krill oil, maple seed oil, sacha inchi oil, milk thistle seed oil, conjugated linoleic acid, and shea butter.

[0080] Specific embodiment 16 is the nutritional emulsion according to specific embodiment 15, wherein the sunflower seed oil is high oleic sunflower seed oil.

[0081] Specific embodiment 17 is a nutritional emulsion according to specific embodiment 1, wherein the nutritional emulsion contains arachidonic acid (ARA) and phospholipid-bound docosahexaenoic acid (DHA).

[0082] Specific embodiment 18 is a method for preparing a nutritional emulsion according to any one of specific embodiments 1-17, the method comprising the following steps:

[0083] (1) The egg yolk phospholipids, the OPO-containing triglycerides, the raw material oil, and water are mixed to obtain a dispersion; and

[0084] (2) The dispersion is subjected to shearing and homogenization processes in sequence, wherein the shearing process includes shearing the dispersion at a rotation speed of 3000-5000 rpm under heating, and the homogenization process includes homogenizing the sheared dispersion under a pressure of 300-400 bar under heating.

[0085] Specific embodiment 19 is the method according to specific embodiment 18, wherein in step (2), the shearing process is carried out in a temperature range of 55℃-70℃.

[0086] Specific implementation 20 is the method according to specific implementation 18, wherein in step (2), the shearing process is performed for 3-5 minutes.

[0087] Specific implementation 21 is the method according to specific implementation 18, wherein in step (2), the homogenization process is carried out in a temperature range of 55℃-70℃.

[0088] Specific implementation 22 is the method according to specific implementation 18, wherein in step (2), the homogenization process is performed for 5-10 minutes.

[0089] Specific implementation 23 is the method according to specific implementation 18, wherein step (1) includes:

[0090] The egg yolk phospholipids and the raw material oil are mixed to obtain a premix, and then the premix is ​​mixed with the OPO-containing triglyceride and water to obtain the dispersion.

[0091] Specific embodiment 24 is the method according to specific embodiment 23, wherein the raw material oil comprises high oleic sunflower seed oil.

[0092] The present invention will now be described in more detail with reference to embodiments. It should be noted that these descriptions and embodiments are intended to facilitate understanding of the invention and are not intended to limit the invention. The scope of protection of the present invention is defined by the appended claims.

[0093] Example

[0094] In this invention, unless otherwise specified, all reagents used are commercially available products and are used directly without further purification.

[0095] Table 1 Raw Material List

[0096]

[0097] Table 2 Fatty acid composition of OPO-containing triglycerides

[0098]

[0099]

[0100] Test methods

[0101] The stability of the nutritional emulsions prepared in the following examples and comparative examples was tested according to the test methods described in detail below.

[0102] Stability testing

[0103] Take less than 300g of the nutrient emulsion prepared in each of the examples and comparative examples and add it to a 500mL beaker. Let the samples stand at room temperature in the dark for 10 days, and then judge their uniformity by observing the appearance of the samples.

[0104] The observation data came from ten evaluators in the field of nutritional emulsion production. They visually inspected the appearance of the samples and scored them according to the following criteria:

[0105] 9-10 minutes: Mix thoroughly and evenly;

[0106] 7-8 points: Most of the mixture is evenly mixed;

[0107] 5-6 points: Small amount of sediment;

[0108] 3-4 points: Significant sedimentation; and

[0109] 1-2 points: Completely stratified.

[0110] Finally, the average score from the ten reviewers was used as the evaluation score for the sample. Samples scoring below 7 points were not suitable as nutritional emulsion products due to the presence of sediment.

[0111] Example 1 (E1)

[0112] One part by weight of ELIP 3020, 19 parts by weight of OPO-containing triglycerides, and 80 parts by weight of purified water were simultaneously added to a high-speed shear tank (model T50D, IKA GmbH, Germany) and dispersed by high-speed shearing at 3000 rpm for 3 minutes at 70°C. Then, the dispersion treated by high-speed shearing was transferred to a high-pressure homogenizer (model PANDA PLUS 2000H, GEA GmbH, Germany) and homogenized at 55°C and 300 bar for 5 minutes to obtain nutritional emulsion 1.

[0113] The particle size of the oil droplets formed in the nutrient emulsion 1 was detected using a multi-source laser diffraction method with a particle size analyzer (Mastersizer 3000, Malvern). The average particle size D of the oil droplets formed in the nutrient emulsion 1 was determined. [4，3 The particle size is 1.312 μm, and the particle size D is... 50 It is 1.217 μm, and the particle size D 90 It is 2.230 μm.

[0114] The stability of nutritional emulsion 1 was tested according to the method described in detail in the above test method section. The results of the stability test are shown in Table 3 below.

[0115] Examples 2-7 (E2-E7) and Comparative Examples 1-12 (CE1-CE12)

[0116] Examples 2-7 (E2-E7) and Comparative Examples 1-12 (CE1-CE12) were carried out in a manner similar to that of Example 1, except that the types and proportions of each raw material, the process conditions of shearing treatment or homogenization treatment were changed as described in Table 3, in order to prepare nutritional emulsions 2-7 and comparative nutritional emulsions 1-12.

[0117] The particle size of the nutrient emulsions prepared in the above examples and comparative examples was measured using a particle size analyzer (Mastersizer 3000, Malvern) with multi-source laser diffraction, in the same manner as described in Example 1. The results are shown in Table 3 below. It should be noted that if obvious stratification is observed in the prepared nutrient emulsion, the above particle size measurement is not performed, and the corresponding part in Table 3 is simply marked "stratification".

[0118] In addition, based on the stability methods described in detail in the above test methods section, stability tests were conducted on nutritional emulsions 2-7 and comparative nutritional emulsions 1-12. The results for the emulsions are shown in Table 3 below.

[0119]

[0120] As shown in Table 3 above, when the composition and content of the nutritional emulsion are controlled according to the technical solution of the present invention (i.e., the weight ratio of the egg yolk phospholipid to the OPO-containing triglyceride is in the range of 1:40 to 3:7) and the nutritional emulsion is prepared according to specific process conditions (i.e., the dispersion is subjected to shearing and homogenization treatments in sequence, wherein the shearing treatment is performed at a rotation speed of 3000-5000 rpm under heating, and the homogenization treatment is performed under a pressure of 300-400 bar under heating), the resulting nutritional emulsion forms particles with a specific particle size (i.e., average particle size D). [4,3] Oil droplets (within the range of 0.8-1.5 μm) contribute to the good system stability of the nutrient emulsion.

[0121] By comparing the results of Example 1 (E1) with those of Comparative Example 1 (CE1), it can be seen that when the weight ratio of egg yolk phospholipid to the OPO-containing triglyceride is too small (for example, in CE1, the ratio is less than 1:40), the amount of egg yolk phospholipid as an emulsifier is too small, and it cannot completely stabilize the oil phase system containing OPO, resulting in stratification.

[0122] By comparing the results of Example 5 (E5) with those of Comparative Example 10 (CE10), it can be seen that when the weight ratio of egg yolk phospholipids to the OPO-containing triglycerides is too large (for example, in CE10, the ratio is 1:2, which is greater than 3:7), the average particle size D of the oil droplets formed in the nutrient emulsion is higher. [4，3] The size is much larger than 1.5 μm, which makes the system less stable. The emulsion showed some precipitation after 10 days of standing.

[0123] Although specific embodiments have been shown and described herein, those skilled in the art will understand that various alternative and / or equivalent embodiments can be used instead of the shown and described specific embodiments without departing from the scope of the invention. This application is intended to include any improvements or modifications to the specific embodiments discussed herein. Those skilled in the art will understand that various modifications and changes can be made without departing from the scope of the invention. Such modifications and changes are intended to fall within the scope of the invention as defined in the appended claims.

Claims

1. A nutritional emulsion, said nutritional emulsion comprising egg yolk lecithin, OPO-containing triglycerides, raw material oil, and water, wherein: The weight ratio of the egg yolk phospholipids to the OPO-containing triglycerides is in the range of 1:40 to 3:7; The average particle size D of the oil droplets formed in the nutritional emulsion [4,3] Within the range of 0.8-1.5 μm; and In the OPO-containing triglycerides, the 2-palmitic acid accounts for at least 52% of the total palmitic acid, and the OPO content is at least 40% by weight.

2. The nutritional emulsion according to claim 1, wherein the particle size D of the oil droplets formed in the nutritional emulsion is... 50 Less than 1.5μm.

3. The nutritional emulsion according to claim 1, wherein the particle size D of the oil droplets formed in the nutritional emulsion is... 90 Less than 2.5μm.

4. The nutritional emulsion according to claim 1, wherein the weight ratio of the egg yolk phospholipid to the OPO-containing triglyceride is in the range of 1:40 to 1:

3.

5. The nutritional emulsion according to claim 1, wherein the weight ratio of the egg yolk phospholipid to the OPO-containing triglyceride is in the range of 1:20 to 1:

15.

6. The nutritional emulsion according to claim 1, wherein the sum of the weights of the egg yolk phospholipids and the OPO-containing triglycerides accounts for 8-30% of the total weight of the nutritional emulsion.

7. The nutritional emulsion according to claim 1, wherein the sum of the weights of the egg yolk phospholipids and the OPO-containing triglycerides accounts for 8-20% of the total weight of the nutritional emulsion.

8. The nutritional emulsion according to claim 1, wherein the water accounts for more than 80% of the total weight of the nutritional emulsion.

9. The nutritional emulsion according to claim 1, wherein the water accounts for 80-90% of the total weight of the nutritional emulsion.

10. The nutritional emulsion according to claim 1, wherein the sum of the weights of the egg yolk phospholipids, the OPO-containing triglycerides, and the raw material oil accounts for 10-20% of the total weight of the nutritional emulsion.

11. The nutritional emulsion according to claim 1, wherein the OPO is 1,3-dioleoyl-2-palmitoylglycerol triglyceride.

12. The nutritional emulsion according to claim 1, wherein the egg yolk phospholipid comprises 55-82% by weight of phosphatidylcholine (PC), 11-20% by weight of phosphatidylethanolamine (PE), 2-4% by weight of sphingomyelin (SM) and 2-9% by weight of lysophospholipid, wherein the lysophospholipid comprises lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE).

13. The nutritional emulsion according to claim 12, wherein the egg yolk phospholipid further comprises 1-3% by weight of DHA and 2-4% by weight of ARA.

14. The nutritional emulsion according to claim 1, wherein the raw material oil is selected from one or more of vegetable oils or animal oils.

15. The nutritional emulsion according to claim 1, wherein the raw material oil is selected from one or more of the following groups: sunflower seed oil, medium-chain triglycerides, coconut oil, flaxseed oil, anhydrous butter, palm kernel oil, DHA algal oil, fish oil, walnut oil, camellia oil, perilla seed oil, sea buckthorn seed oil, avocado oil, wheat germ oil, blackcurrant seed oil, borage oil, eucommia seed oil, evening primrose oil, soybean oil, rapeseed oil, corn oil, peanut oil, safflower seed oil, palm oil, rice bran oil, sesame oil, γ-linolenic acid oil, tomato seed oil, peony seed oil, krill oil, maple seed oil, sacha inchi oil, milk thistle seed oil, conjugated linoleic acid, and shea butter.

16. The nutritional emulsion according to claim 15, wherein the sunflower seed oil is high-oleic sunflower seed oil.

17. The nutritional emulsion according to claim 1, wherein the nutritional emulsion comprises phospholipid-bound arachidonic acid (ARA) and docosahexaenoic acid (DHA).

18. A method for preparing a nutritional emulsion according to any one of claims 1-17, the method comprising the following steps: (1) The egg yolk phospholipids, the OPO-containing triglycerides, the raw material oil, and water are mixed to obtain a dispersion; and (2) The dispersion is subjected to shearing and homogenization processes in sequence, wherein the shearing process includes shearing the dispersion at a rotation speed of 3000-5000 rpm under heating, and the homogenization process includes homogenizing the sheared dispersion under a pressure of 300-400 bar under heating.

19. The method according to claim 18, wherein in step (2), the shearing process is performed in a temperature range of 55°C to 70°C.

20. The method according to claim 18, wherein in step (2), the shearing process is performed for 3-5 minutes.

21. The method according to claim 18, wherein in step (2), the homogenization process is carried out in a temperature range of 55°C to 70°C.

22. The method according to claim 18, wherein in step (2), the homogenization process is performed for 5-10 minutes.

23. The method of claim 18, wherein step (1) comprises: The egg yolk phospholipids and the raw material oil are mixed to obtain a premix, and then the premix is ​​mixed with the OPO-containing triglyceride and water to obtain the dispersion.

24. The method of claim 23, wherein the feedstock oil comprises high-oleic sunflower oil.

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