Preparation method of infant formula milk powder capable of simulating breast milk and added with lecithin and MFGM ingredients

Abstract

The invention discloses a preparation method of breast milk simulating infant formula milk powder added with lecithin and MFGM ingredients, and belongs to the field of infant ingredient powder processing. The preparation method comprises the following steps: (1) analyzing composition of phospholipids from different sources, and selecting egg yolk lecithin compounded with MFGM; and (2) determining the optimal ratio of the added egg yolk lecithin to the MFGM ingredient to be 1: 1. And (3) selecting an optimal process: mixing the MFGM ingredients and egg yolk lecithin with vegetable oil, homogenizing to prepare an emulsion, and finally spraying to prepare the milk powder. According to the research, lecithin and MFGM ingredients are selected to be compounded and added into the infant formula milk powder, so that the fat interface and digestion characteristics can be improved, and the condition that infants become fat due to poor digestion and absorption of lipid is avoided.

Description

Technical Field

[0001] This invention belongs to the field of infant formula processing technology, specifically relating to an infant formula with added lecithin and MFGM ingredients and its preparation method. Background Technology

[0002] For many years, infant formula has been the best alternative to breast milk, designed to meet the needs of infant growth and development. Lipids are an important energy source, accounting for 3-5% of breast milk and providing infants with more than 50% of their energy. Infants' metabolic phenotypes tend to compensate for high energy demands, with breastfed infants showing a greater preference for fat metabolism. However, formula-fed infants exhibit a "protein-preferred" metabolic phenotype. This difference in metabolic phenotypes may be a result of "fat underutilization" in formula-fed infants, meaning digestion affects metabolism. Furthermore, the main factors influencing fat digestion and absorption are the structure and composition of triglycerides (TAGs) and the interfacial properties of fat globules. Although many infant formulas use blended vegetable oils to mimic the TAG composition of breast milk, fat digestion in infant formula still differs from that in breast milk. This may be because milk fat globules (MFGs) are characterized by a three-layered membrane covering known as the "milk fat globule membrane (MFGM)." Infant formula often lacks MFGM components due to processing methods or the use of vegetable oils.

[0003] Although infant formula containing MFGM fragments has made significant nutritional progress in recent years, studies have found that while MFGM-added infant formula shows improvements in nutritional function, fat interface, and digestive properties, it still differs from breast milk. Furthermore, commercially available MFGM products are primarily whey protein powders rich in MFGM, with low phospholipid content (7-8%), making it difficult for them to form a film on the fat surface. Therefore, it may be necessary to combine other phospholipids and improve processing techniques to mimic the structure and interface of milk fat globules.

[0004] Therefore, this study selected specific phospholipids and MFGM ingredients to be added to infant formula, and adopted appropriate addition methods to make it closer to breast milk in structure and composition, improve fat interface and digestive properties, thereby improving the infant's digestive and metabolic abilities and avoiding the infant's obesity due to poor lipid digestion and absorption. Summary of the Invention

[0005] This invention addresses the technical problem of existing commercially available infant formula lacking phospholipids and MFGM, leading to poor digestion and absorption in infants and consequently causing various immune metabolic diseases. It provides a method for preparing a breast milk-mimicking infant formula with added lecithin and MFGM. One of the objectives of this invention is to analyze the composition of phospholipids from different sources and ultimately select the optimal phospholipid for blending with MFGM. The specific selection method includes the following steps: (1) Liquid chromatography-mass spectrometry (LC-MS) was used to analyze the composition of MFGM ingredients, egg yolk lecithin and soybean lecithin to determine the types, distribution and molecular content of phospholipids, and to perform differential analysis.

[0006] (2) Gas chromatography-mass spectrometry (GC-MS) was used to analyze the fatty acid composition of MFGM ingredients, egg yolk lecithin and soybean lecithin to determine the types and relative contents of fatty acids and to perform differential analysis.

[0007] The preferred condition is to select egg yolk lecithin and MFGM for compounding.

[0008] The second objective of this invention is to determine the optimal ratio of added lecithin and MFGM ingredients. The specific selection method includes the following steps: Simulated milk fat globule emulsions with different ratios of lecithin and MFGM were prepared. The stability, particle size, potential, encapsulation efficiency, interfacial protein composition and structure of the emulsions were measured. The ratio of egg yolk lecithin to MFGM was determined by using encapsulation efficiency, stability, microstructure and lipolysis rate as evaluation indicators.

[0009] The preferred condition is to select egg yolk lecithin and MFGM ingredients to be compounded in a 1:1 ratio.

[0010] The third objective of this invention is to determine the process for adding egg yolk lecithin and MFGM, and the specific method is as follows: Infant formula 1 (Concept IF1) was prepared by first homogenizing a single MFGM ingredient with vegetable oil to form an emulsion, and then mixing it with other ingredients. Infant formula 2 (Concept IF2) was prepared by replacing the single MFGM ingredient with a complex of lecithin and MFGM ingredients in the same manner. Infant formula 3 was prepared by homogenizing vegetable oil with lecithin, MFGM ingredients and other ingredients in one go, and then using the same method as infant formula 2.

[0011] The preferred condition is the selection of the additive process for infant formula milk powder 2.

[0012] The beneficial effects of this invention are as follows: This invention provides a method for preparing infant formula milk powder that mimics breast milk by adding lecithin and FGM ingredients. Compared with existing commercially available products, the product forms a fat globule interface and structure that is closer to breast milk. This experiment selected egg yolk lecithin, which is closest to breast milk, as the lecithin source by analyzing the composition of phospholipids from different sources. Simultaneously, the optimal ratio of egg yolk lecithin to MFGM ingredients was determined by measuring the stability, particle size, potential, encapsulation efficiency, interfacial protein composition, and structure of the emulsion. Finally, infant formula emulsions were prepared using three different processes, and the interfacial phospholipid and interfacial protein composition of the fat was analyzed. The microstructure of the fat globules was observed to determine the optimal order of addition and preparation process for preparing infant formula milk powder.

[0013] The infant formula milk powder that mimics breast milk provided by this invention can improve the lipid digestibility of infants and young children, and minimize the risk of obesity and immune metabolic diseases caused by indigestion in infants and young children. Attached Figure Description

[0014] Figure 1 PCA analysis of phospholipids from three sources Figure 2 Stability constants of simulated milk fat globule emulsions with different ratios of lecithin and MFGM Figure 3 Chemical stability of simulated milk fat globule emulsions with different ratios of lecithin and MFGM Figure 4 Interfacial structure of fats in breast milk and infant formula Figure 5 , Figure 6 The average particle size during the digestion of breast milk and infant formula Detailed Implementation

[0015] Those skilled in the art can refer to the content of this document and appropriately improve the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate alterations and combinations to the methods and applications described herein without departing from the content and scope of this invention to implement and apply the technology of this invention.

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, which can be obtained commercially by those skilled in the art. Example

[0017] This embodiment analyzes the composition of phospholipids from different sources.

[0018] (1) As Figure 1 Firstly, PCA analysis of the phospholipids in MFGM and lecithin revealed differences in the phospholipid composition of the three groups: MFGM, egg yolk lecithin, and soybean lecithin. The results showed that the three materials were distributed in independent quadrants with no regional overlap, indicating significant differences in the distribution of phospholipids from the three sources and good distinguishability.

[0019] Table 1 shows the phospholipid types with a content of 0.5% or higher in the three materials. The results indicate that the most abundant typical phospholipids are PC, PE, and SM. Egg yolk lecithin and soy lecithin had the highest PC content (16:0 / 20:4), accounting for over 25% of the total phospholipids. Egg yolk lecithin and soy lecithin also contained relatively high levels of PC (16:0 / 20:5). Next, MFGM had a relatively high PC content (16:0 / 18:1), which was also found in high levels in egg yolk lecithin, but was not detected in soy lecithin. MFGM also contained a relatively high amount of PE (18:1 / 18:2), while egg yolk lecithin and soy lecithin had relatively high PE content (18:0 / 18:4), and soy lecithin contained very little SM. The main phospholipids (SMs) in breast milk include SM (d18:1 / 23:2), SM (d16:1 / 18:0), SM (d18:1 / 18:1), and SM (d18:1 / 22:0). The types of SMs in soy lecithin and egg yolk lecithin differ significantly from those in breast milk, while phospholipids from animal milk sources are likely closer to those in breast milk. However, the SM content in egg yolk lecithin may be higher than that in soy lecithin.

[0020] Table 1 Phospholipid class Mass fraction MFGM Egg yolk lecithin Soy lecithin PC (10:0 / 18:0) 677.50 1.34±0.02 _ _ PC (10:0 / 20:0) 705.53 2.53±0.05 _ _ PC (10:0 / 21 :0) 719.55 1.26±0.02 _ _ PC (10:0 / 22:0) 733.56 2.83±0.05 _ _ PC (10:0 / 23:0) 747.58 1.03±0.02 _ _ PC (12:0 / 14:1) 647.45 _ 1.21±0.00 _ PC (13:0 / 18:2) 715.52 0.99±0.02 2.24±0.01 2.65±0.01 PC (14:0 / 22:6) 777.53 _ 0.77±0.00 1.78±0.00 PC (16:0 / 18:1) 759.58 6.80±0.12 2.81±0.01 _ PC (16:0 / 18:3) 755.55 _ 0.51±0.00 0.97±0.01 PC (16:0 / 20:3) 783.58 4.74±0.08 5.01±0.01 3.31±0.00 PC (16:0 / 20:4) 781.56 0.97±0.02 26.24±0.58 29.77±0.00 PC (16:0 / 20:5) 779.55 _ 7.90±0.01 13.63±0.00 PC (16:0 / 22:6) 805.56 _ 0.92±0.00 _ PC (16:1 / 22:6) 803.55 _ 2.22±0.00 1.26±0.01 PC (18:0 / 18:2) 785.59 8.82±0.15 2.90±0.00 6.28±0.00 PC (18:2 / 0:0) 519.33 _ 1.48±0.00 0.87±0.00 PC (18:3 / 20:5) 801.53 _ 0.78±0.00 0.96±0.01 PC (20:5 / 0:0) 541.32 _ 0.85±0.00 _ PC (0-17:0 / 20:4) 781.60 _ 0.67±0.00 _ PE (14:1 / 22:4) 737.50 _ 0.84±0.00 1.50±0.01 PE (17:0 / 22:1) 787.61 2.75±0.05 _ _ PE (18:0 / 18:1) 745.56 1.42±0.03 _ _ PE (18:0 / 18:4) 739.52 _ 3.64±0.004 3.70±0.01 PE (18:1 / 18:1) 743.55 3.06±0.05 _ 0.64±0.00 PE (18:1 / 18:2) 741.53 2.88±0.05 0.91±0.004 0.67±0.00 PE (19:0 / 18:0) 761.59 2.18±0.04 _ _ PE-NMe (16:0 / 18:1) 731.55 2.17±0.04 _ _ PE-NMe (18:1 / 18:1) 757.56 8.64±0.15 14.4±0.58 13.37±0.01 PG (19:0 / 22:1) 846.64 _ 0.69±0.00 0.51±0.00 PG (20:0 / 22:1) 860.65 _ 1.67±0.01 0.99±0.00 SM (d16:1 / 17:0) 688.55 _ 2.00±0.00 _ SM (d18:0 / 14:0) 676.55 2.12±0.04 _ _ SM (d18:0 / 16:0) 704.58 1.00±0.02 _ _ SM (d18:1 / 14:0) 674.54 4.16±0.07 _ _ SM (d18:1 / 16:0) 702.57 2.50±0.04 _ _ SM (d18:1 / 17:0) 716.58 _ 1.23±0.00 _ SM (d18:1 / 19:0) 744.61 _ 0.98±0.00 _ SM (d18:1 / 20:0) 758.63 3.43±0.06 _ _ SM (d18:1 / 22:0) 786.66 6.81±0.11 _ _ SM (d18:1 / 24:0) 814.69 2.34±0.04 _ _ SM (d18:1 / 25:0) 828.71 _ 1.15±0.00 0.59±0.00 Cer (d18:0 / 14:0) 511.50 _ 1.15±0.002 0.65±0.005 Cer (t18:1 / 26:0) 725.65 0.52±0.01 _ _ Example

[0021] Emulsion Preparation: MFGM ingredients and lecithin were mixed in proportions (0:1; 1:3; 1:1; 3:1; 1:0), and a 2% (w / v) solution was prepared with ultrapure water. The pH was adjusted to 6.7 with 1M NaOH, and the mixture was magnetically stirred (750 rpm, 45℃) overnight to form the aqueous phase of the emulsion. The vegetable oils in the oil phase were mixed in the following proportions: rapeseed oil (10%), sunflower oil (10%), soybean oil (15%), coconut oil (25%), palm oil (25%), and corn oil (15%). The aqueous and oil phases were mixed in a 4:1 ratio, premixed using a high-speed shear homogenizer, filtered through a 60-mesh screen, and then homogenized under different pressures using a microfluidic high-pressure homogenizer to prepare the emulsion.

[0022] (1) To determine the stability constant (KE) of emulsions with different ratios of lecithin and MFGM, the emulsions were centrifuged at 3000 rpm for 15 min. 0.5 mL of the lower layer was transferred to a 10 mL volumetric flask and diluted to volume with ultrapure water. The absorbance value A (450 nm) was measured. Another 0.5 mL of the uncentrifuged sample was diluted to 10 mL, and the absorbance value A0 was measured. The KE value was calculated using the following formula: like Figure 2 As shown, the stability constant of the emulsion first decreases and then increases with the ratio of lecithin to MFGM. The stability constant is lowest when the ratio of lecithin to MFGM is 1:1. This indicates that the stability of the emulsion first increases and then decreases with the increase of the ratio of egg yolk lecithin to MFGM, with the highest stability at a 1:1 ratio. After adding egg yolk lecithin, the lecithin coexists and interacts with the proteins in the MFGM ingredient at the interface, thereby improving the stability of the simulated milk fat globule emulsion.

[0023] (2) To determine the stability of emulsions with different ratios of lecithin and MFGM, a TTH solution was prepared. 15 g of trichloroacetic acid (TCA) and 0.375 g of thiobarbituric acid (TBA) were weighed and dissolved in 100 mL of 0.25 M HCl solution. The solution was cooled and filtered through a 0.45 μM organic filter membrane to obtain a TCA-TBA-HCl solution, which was called TTH.

[0024] The malondialdehyde (MDA) content was determined using the TBA method to assess the total level of lipid oxidation

[77] . 0.4 mL of sample and 2.5 mL of TTH solution were added to a 10 mL centrifuge tube and mixed vigorously. The mixture was heated in an immersion water bath for 30 minutes and then cooled to room temperature. Then, 2.5 mL of TTH solution was added and mixed thoroughly. After centrifugation (4000 × g) for 10 min, the absorbance A of the supernatant was measured (at 532 nm).

[0025] Where A is the absorbance value; b is the length of the absorption cell, in cm, usually 1 cm; a is the absorption coefficient, usually 4870, in L·g⁻¹·cm⁻¹.

[0026] like Figure 2 The malondialdehyde (MDA) content initially increased and then decreased with increasing lecithin to MFGM ratio. The highest MDA content and best stability were observed when the ratio was 1:1. Therefore, MDA content decreased when the ratio of lecithin to MFGM exceeded 1:1. This may be because the high concentration of phospholipids effectively slowed the oxidation of the core vegetable oil and improved the antioxidant properties of the emulsion. Example

[0027] (1) Preparation process of infant formula milk powder 2: All ingredients except vegetable oil, lecithin, and MFGM are slowly added to an equal mass of 40°C water while stirring and mixed thoroughly. After all ingredients are dissolved, the mixture is allowed to stand for 1 hour for hydration to obtain solution A. Simulated milk fat globule emulsions (solution B) are prepared by mixing the optimal ratio of lecithin and MFGM (infant formula 2) with the compound vegetable oil as described above.

[0028] Mix liquid A and emulsion B in a specified ratio and homogenize using a high-speed shear homogenizer at 1000 r / min. Then homogenize at pressures of 15 MPa, 20 MPa, and 25 MPa respectively.

[0029] Disinfection and sterilization: 65℃ water bath for 30 minutes Powder spraying: Use a spray dryer with an inlet air temperature of 180℃ and an outlet air temperature controlled at 90℃.

[0030] Comparative Example 1: All ingredients except vegetable oil, lecithin, and MFGM were slowly added to an equal mass of 40°C water while stirring and mixed thoroughly. After all ingredients were dissolved, the mixture was allowed to stand for 1 hour to hydrate, yielding solution A. Simulated milk fat globule emulsions were prepared by mixing the single MFGM ingredient (infant formula 1) with the compound vegetable oil as described above, yielding solution B. Subsequent processing was the same as for infant formula 2.

[0031] Comparative Example 3: Mix all powdered ingredients — dissolve in an equal amount of purified water — hydrate in a 45℃ water bath for 1 hour — add vegetable oil and purified water — mix all ingredients — emulsify and shear — homogenize (15MPa, 20MPa, 25MPa) — sterilize (65℃, 30min) — spray dry (inlet air temperature 180℃, outlet air temperature 90℃).

[0032] Comparative Example 4: Commercially available infant formula milk powder emulsion Comparative Example 5: Breast Milk Infant formula 1 and 2 are labeled as "Concept IF1" and "Concept IF2" respectively; infant formula 3, which has a different addition method, is labeled as "IF3"; commercially available infant formula emulsion is labeled as IF4; and breast milk is named HM.

[0033] (2) Determination of the interfacial microstructure formed by different addition methods. The microstructure was imaged using an ultra-high resolution microscope system. The emulsion sample (0.2 mL) was diluted to 10 mL with ultrapure water and gently mixed. Phospholipids at the lipid droplet interface were labeled with the fluorescent probe Rd-DOPE at a concentration of 1 mg / mL (chloroform preparation). The protein concentration at the lipid droplet interface was labeled with 1 mg / mL (Milli-Q configuration) FCF. Next, 120 μL of the sample was mixed with 15 μL of Rd-DOPE and 60 μL of FCF and incubated in the dark at room temperature for 1 hour. The mixture (0.5 μL) was dropped onto a glass slide, and the edges of the coverslip were coated with nail polish to fix the sample in place and prevent it from drying out. The sample observation temperature was 25 °C, and the excitation wavelengths corresponding to Rd-DOPE and FCF were 568 nm and 488 nm, respectively. The ultra-high resolution microscope was equipped with a 63x oil lens. The numerical aperture of the lens was 1.42.

[0034] like Figure 4 In breast milk, both labeled phospholipids and proteins exhibit clearly defined rings, and overlap between phospholipids and proteins was observed in milk fat globules. The rings in breast milk are larger than those in infant formula. Commercially available infant formula (IF4) lacks rings and contains large aggregates. Concept IF1 and IF3 have structures different from breast milk and are superior to IF4. Notably, the interfacial structure of Concept IF2, which is a compound of lecithin and MFGM ingredients homogenized with vegetable oil to form an emulsion before being added to other ingredients, is more similar to that of breast milk, consisting of phospholipids and proteins encapsulated and uniformly dispersed (with many small rings as indicated by arrows). Pre-preparing the emulsion may have ensured preferential adsorption of MFGM and phospholipids on the oil surface.

[0035] (3) Determination of particle size changes during digestion under different addition methods. The emulsion (0.1 mL) was diluted to 50 mL with ultrapure water to achieve a 10% masking level, and then the volume-weighted particle size distribution and average diameter (D4,3) of the fat globules in the sample were measured. At room temperature, the refractive indices were set to 1.46 (466 nm) and 1.458 (633 nm), and the refractive index of the dispersed phase (water) was set to 1.33. Potentiometric measurements were performed by diluting the sample (15 μL) 400 times with buffer (20 mM imidazole, 50 mM sodium chloride, 5 mM calcium chloride) and measuring the potential of the sample at 25 °C using a Nano ZS90 particle size and potential analyzer. Each sample was measured three times.

[0036] The average particle size of breast milk measured in this study was (3.73 ± 0.15) μm. The average particle size of fat in infant formula was around 0.4 µm, and the particle size of commercially available infant formula (IF4) was d = 0.37 ± 0.02 µm.Figure 6 Initially, the particle size of breast milk exhibits a bimodal distribution, while infant formula milk powder shows a unimodal distribution.

[0037] like Figure 5 As shown, after 30 minutes of gastric digestion, the particle size of Concept IF1 and IF4 increased, while the particle size of breast milk, Concept IF2, and IF3 decreased. During digestion, the average particle size of breast milk increased in the first two hours, reaching its minimum at the end of intestinal digestion. The particle size distribution was unimodal at the beginning of gastric and intestinal digestion and bimodal at the end. The particle size distribution of Concept IF2 during gastric digestion differed from other infant formulas, showing no large particle size distribution. While infant formula exhibited particle size increase after entering the intestines for digestion, Concept IF2 showed the least significant increase, the smallest particle size, and displayed a bimodal distribution similar to breast milk, indicating better stability.

[0038] The contents not described in detail in this specification are well-known to those skilled in the art. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be defined by the claims.

Claims

1. A method for preparing a breast milk-simulating infant formula powder with added lecithin and MFGM ingredients, the method comprising the following steps: (1) The results of PCA analysis of phospholipids in MFGM ingredients and egg yolk lecithin revealed the differences in phospholipid composition among the three groups of MFGM, egg yolk lecithin and soybean lecithin, and egg yolk lecithin was selected as the main source of phospholipids; (2) Mix MFGM ingredients and lecithin in a 1:1 ratio, prepare a 2% (w / v) solution with ultrapure water, adjust the pH to 6.7 with 1M NaOH, and stir magnetically (750 rpm, 45℃) overnight to form the aqueous phase of the emulsion; the mixing ratio of vegetable oils in the oil phase is as follows: rapeseed oil (10%), sunflower seed oil (10%), soybean oil (15%), coconut oil (25%), palm oil (25%), and corn oil (15%). Mix the aqueous phase and oil phase in a 4:1 ratio, premix with a high-speed shear homogenizer, filter through a 60-mesh screen, and homogenize under different pressures using a microfluidic high-pressure homogenizer to prepare the emulsion; (3) Add all ingredients except vegetable oil, lecithin and MFGM ingredients slowly to an equal mass of 40°C water under stirring and mix evenly. After all ingredients are dissolved, let stand for 1 hour to hydrate and obtain liquid A. Prepare simulated milk fat globule emulsions by mixing the optimal ratio of lecithin and MFGM ingredients (infant formula milk powder 2) with compound vegetable oil in the above manner to obtain liquid B. Mix liquid A and emulsion B in proportion and mix with a high-speed shear homogenizer at 1000 r / min. Then homogenize with pressures of 15 MPa, 20 MPa and 25 MPa respectively. Sterilize with a 65°C water bath for 30 min. Finally, use a spray dryer with an inlet air temperature of 180°C and an outlet air temperature of 90°C.

2. The method for preparing a simulated breast milk infant formula powder with added lecithin and MFGM ingredients according to claim 1, characterized in that, The phospholipids used are derived from egg yolk lecithin (the optimal source was selected based on the data).

3. The method for preparing a simulated breast milk infant formula powder with added lecithin and MFGM ingredients according to claim 1, characterized in that, The ratio of MFGM ingredients to egg yolk lecithin used is 1:1 (optimal ratio selected based on data).

4. The method for preparing a simulated breast milk infant formula powder with added lecithin and MFGM ingredients according to claim 1, characterized in that, After mixing MFGM ingredients and egg yolk lecithin, the mixture is homogenized with vegetable oil to prepare an emulsion, which is then spray-dried into milk powder (the optimal formula is selected based on data).

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