High-stability calcium-fortified full-nutrition liquid special medical purpose food and preparation method thereof

Abstract

This invention discloses a highly stable calcium-fortified complete nutritional liquid food for special medical purposes and its preparation method. The formula contains the following components at the following mass concentrations: casein 5-6 g / 100 mL, maltodextrin 10-11 g / 100 mL, mixed oil 4-5 g / 100 mL, resistant dextrin 1-2 g / 100 mL, fructooligosaccharides 2-3 g / 100 mL, compound emulsifier 0.3-0.5 g / 100 mL, phosphorus... The ingredients are: lipids 0.2–0.4 g / 100 mL, calcium carbonate 0–0.2 g / 100 mL, compound vitamins 0.1–0.3 g / 100 mL, compound salts 1–2 g / 100 mL, xanthan gum 0.002–0.004 g / 100 mL, carrageenan 0.002–0.004 g / 100 mL, edible flavoring 0.1–0.2 g / 100 mL, and purified water 70–80 g / 100 mL. This invention optimizes the proportions of each component and the processing technology, especially controlling the calcium carbonate content within a specific range and combining it with a key step of homogenization four times under 60 MPa pressure. This allows calcium carbonate and casein to form a stable complex system, effectively inhibiting the Maillard reaction during high-temperature sterilization, significantly improving product color, and simultaneously enhancing the physical stability of the emulsion, preventing precipitation and stratification. The resulting product is highly stable, has good flowability, and is easily absorbed. It can be taken orally or via tube feeding, providing a safe, convenient, and comprehensive nutritional solution for specific disease populations that require calcium fortification support.

Description

Technical Field

[0001] This invention relates to the field of food technology, specifically to a highly stable calcium-fortified complete nutritional liquid food for special medical purposes and its preparation method. Background Technology

[0002] This invention relates to the field of special medical purpose formulation foods, specifically to a calcium-fortified liquid special medical purpose formulation food with high stability and high bioavailability and its industrial preparation method.

[0003] Foods for Special Medical Purposes (FSMP) are specially formulated foods designed to meet the specific nutritional or dietary needs of individuals with restricted food intake, malabsorption, metabolic disorders, or specific disease states, based on medical and nutritional research findings. Complete nutritional formulas can serve as a single source of nutrition to meet the daily needs of the target population. Ready-to-use liquid formulations, in particular, offer irreplaceable advantages in hospital and home nutritional support due to their immediate use, lack of need for reconstitution, ease of standardized tube feeding, and portability. However, achieving commercial sterility and ensuring high physicochemical stability of liquid complete nutritional formulas during their shelf life faces a series of significant technical challenges, especially in the processes of mineral fortification and high-temperature heat treatment.

[0004] Calcium, a key mineral for maintaining bone health, nerve conduction, and muscle function, is an indispensable core nutrient in complete nutritional formulas. For individuals at risk of osteoporosis, recovering from fractures, or those with long-term bed rest, adequate and efficient calcium supplementation through medical foods is crucial. Stable incorporation of calcium, especially inorganic calcium sources with limited solubility, into complex liquid complete nutritional systems and its industrial production has long been a prominent challenge for the industry. The main challenges lie in two aspects: First, the chemical instability arising from thermal processing. Liquid products must undergo high-temperature sterilization to ensure commercial sterility. During this process, proteins (such as casein) and reducing sugars (such as maltodextrin) abundant in the formula are highly susceptible to Maillard reactions, leading to protein denaturation, the production of large amounts of high-molecular-weight polymers, directly disrupting the homogeneity of the emulsion and causing precipitation, layering, and deterioration in color and flavor. Second, the physical instability inherent in the minerals themselves. Calcium ions (Ca²⁺), as potent divalent cations, play a dual role in the system: appropriate amounts of calcium ions may inhibit certain reactions, but excessive amounts can cause strong cross-linking and charge neutralization with proteins and stabilizers, promoting protein flocculation and fat globule aggregation, thus leading to demulsification. These two instability mechanisms intertwine, creating a dilemma in the development of high-calcium liquid formulations: adding no calcium or only a small amount cannot meet nutritional requirements; while conventional calcium addition often leads to a sharp decline in product stability after sterilization or during storage. Furthermore, production process parameters, such as the pressure and number of high-pressure homogenization cycles, have a decisive impact on the formation and stability of the final microparticle structure; insufficient or excessive homogenization cannot achieve the optimal particle distribution to resist the aforementioned instability processes.

[0005] Currently, many industry solutions have limitations: some reduce the calcium fortification level to ensure basic stability, making it difficult to meet the high calcium needs of specific populations; others rely on a large amount of compound emulsifiers and stabilizers to barely maintain the system, but this may lead to problems such as sticky taste, increased costs and label cleanliness, and may not be able to fundamentally solve the essential conflict caused by heat processing and calcium ions.

[0006] Therefore, there is an urgent need for an innovative formulation design and process combination capable of controlling the Maillard reaction process and the physicochemical behavior of calcium ions at the molecular level. Based on this, this invention provides a highly stable calcium-fortified complete nutritional liquid for special medical purposes and its preparation method. This invention achieves synergistic effects by carefully selecting and precisely defining the proportions of proteins, carbohydrates, specific calcium sources, and a complex stabilizing system, combined with optimized high-pressure homogenization process parameters. This solution inhibits the formation of harmful polymers during high-temperature sterilization, precisely controls calcium ions to the optimal inhibition concentration, and combines physical homogenization to construct a stable microstructure. Without relying on excessive additives, this invention successfully develops a complete nutritional liquid with adequate calcium content, excellent sterilization and storage stability, and suitability for industrial production. This product provides a stable, reliable, and highly compliant nutritional solution for patients requiring high calcium support, possessing significant clinical value and market potential. Summary of the Invention

[0007] The main objective of this invention is to provide a highly stable calcium-fortified complete nutritional liquid for special medical purposes and its preparation method. The aim is to provide a highly stable calcium-fortified complete nutritional liquid for special medical purposes that is easily digestible and absorbable, requires no rehydration, has high product safety, and can be directly tube-fed or taken orally, providing nutritional support for patients during treatment, rehabilitation, and maintenance of bodily functions.

[0008] To achieve the above objectives, this invention proposes a highly stable calcium-fortified complete nutritional liquid food for special medical purposes, comprising the following components in the indicated mass concentrations: casein 5-6 g / 100 mL, maltodextrin 10-11 g / 100 mL, mixed oil 4-5 g / 100 mL, resistant dextrin 1-2 g / 100 mL, fructooligosaccharides 2-3 g / 100 mL, compound emulsifier 0.3-0.5 g / 100 mL, and phosphorus... Lipids 0.2-0.4g / 100mL, calcium carbonate 0-0.2g / 100mL, compound vitamins 0.1-0.3g / 100mL, compound salts 1-2g / 100mL, xanthan gum 0.002-0.004g / 100mL, carrageenan 0.002-0.004g / 100mL, edible flavoring 0.1-0.2g / 100mL, purified water 70-80g / 100mL.

[0009] Optionally, the components include the following mass concentrations: casein 5.5 g / 100 mL, maltodextrin 10.2 g / 100 mL, mixed oil 4.6 g / 100 mL, resistant dextrin 1.2 g / 100 mL, fructooligosaccharides 2.2 g / 100 mL, compound emulsifier 0.4 g / 100 mL, phospholipid 0.3 g / 100 mL, calcium carbonate 0.1 g / 100 mL, compound vitamins 0.2 g / 100 mL, compound salts 1.04 g / 100 mL, xanthan gum 0.003 g / 100 mL, carrageenan 0.003 g / 100 mL, edible flavor 0.11 g / 100 mL, and purified water 75 g / 100 mL.

[0010] Optionally, the blended oil includes low-erucic acid rapeseed oil, medium-chain triglycerides, corn oil, and flaxseed oil.

[0011] Optionally, the low-erucic acid rapeseed oil, medium-chain triglycerides, corn oil, and flaxseed oil are present in the following mass percentages: 74%, 20%, 5.5%, and 0.5%, respectively.

[0012] Optionally, the compound emulsifier includes at least two of stearoyl lactate, sodium carboxymethyl cellulose, and gelatin; and / or,

[0013] The compound vitamins include vitamin A, vitamin D, vitamin E, vitamin K1, vitamin B1, vitamin B2, vitamin B6, vitamin B12, niacin, folic acid, pantothenic acid, vitamin C, and biotin; and / or,

[0014] The compound salt includes sodium chloride, potassium chloride, sodium hexametaphosphate, and sodium metaphosphate.

[0015] This invention also proposes a method for preparing the liquid diabetic special medical purpose formula food as described above, comprising the following steps:

[0016] Step A: Dissolve resistant dextrin, fructooligosaccharides, xanthan gum, carrageenan, and salts together with purified water to obtain the first mixture;

[0017] Step B: Dissolve casein, maltodextrin, and calcium carbonate together with purified water to obtain a second mixture;

[0018] Step C: Dissolve corn oil, low-erucic acid rapeseed oil, medium-chain triglycerides, flaxseed oil, phospholipids, and compound emulsifier in purified water and perform primary emulsification by shearing to obtain the oil phase;

[0019] Step D: Mix the first mixture, the second mixture, and the oil phase, and then add the compound vitamins to obtain the total mixture;

[0020] Step E: Homogenize the total mixture, then bottle and sterilize it to obtain a highly stable calcium-fortified complete nutritional liquid food for special medical purposes.

[0021] Optionally, in step C, the shearing rate is 2700–2900 r / min.

[0022] Optionally, in step D, the pressure of the homogenization process is 50–70 MPa; and / or,

[0023] The homogenization process is repeated 3 to 5 times.

[0024] Optionally, in step C, the sterilization temperature is 120–125°C.

[0025] Optionally, in step C, the sterilization time is 13 to 17 minutes.

[0026] The beneficial effects of this invention are as follows:

[0027] (1) The highly stable calcium-fortified liquid medical food provided by this invention systematically constructs a nutritional and functional system with casein, maltodextrin, and calcium carbonate as key components, and precisely combines resistant dextrin, fructooligosaccharides, phospholipids, and compounded stable colloids. While meeting the goals of complete nutrition and high calcium fortification, it overcomes the stability bottleneck that easily occurs in liquid medical foods during heat processing and long-term storage. This product not only achieves a scientific ratio of key nutrients but also exhibits excellent physical stability during its shelf life, with no fat floating, no protein precipitation, uniform texture, and good fluidity, ensuring the consistency of nutritional composition and bioavailability in each unit dose. It provides a safe, stable, and reliable standardized solution for clinical high-calcium nutritional support.

[0028] (2) This invention achieves intelligent regulation of system stability through the synergy of calcium carbonate and high-pressure homogenization. Calcium carbonate plays a dual regulatory role at specific concentrations: the calcium ions it releases can controllably bind to casein, competitively inhibiting the Maillard reaction and reducing the formation of large polymer molecules; on the other hand, it moderately enhances protein-protein interactions within the optimal concentration range, synergistically forming a robust interfacial film with phospholipids and emulsifiers, and combining with the network structure of xanthan gum and carrageenan to comprehensively improve emulsion stability. Combined with optimized homogenization processes, a particle system with uniform particle size and complete interfaces is formed, synergistically ensuring the high stability of the product from the molecular to the macroscopic level. This design enables the product to simultaneously meet the requirements of high calcium fortification, excellent processing tolerance, and long-term storage stability, possessing significant industrial and clinical value. Attached Figure Description

[0029] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0030] Figure 1 The images show the appearance of the finished FSMP products obtained in Examples 1-3 and Comparative Examples 1-3 of this invention.

[0031] Figure 2 These are grafting degree diagrams obtained from Embodiments 1-3 and Comparative Examples 1-3 of the present invention;

[0032] Figure 3 The diagrams show the 5-hydroxymethylfurfural obtained in Examples 1-3 and Comparative Examples 1-3 of this invention;

[0033] Figure 4 These are the black-like images obtained in Examples 1-3 and Comparative Examples 1-3 of the present invention;

[0034] Figure 5 The particle size distributions of the finished FSMP emulsions obtained in Examples 1-3 and Comparative Examples 1-3 of this invention are shown below.

[0035] Figure 6 These are FSMP SEM images of the finished products obtained in Examples 1-3 and Comparative Examples 1-3 of the present invention;

[0036] Figure 7 The centrifugal sedimentation rate diagrams of the finished FSMP obtained in Examples 1-3 and Comparative Examples 1-3 of this invention are shown.

[0037] Figure 8 The apparent viscosity diagrams of the finished FSMP obtained in Examples 1-3 and Comparative Examples 1-3 of this invention are shown.

[0038] Figure 9 The above are stability analysis diagrams of the finished FSMP products obtained in Examples 1-3 and Comparative Examples 1-3 of this invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially. Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, or solution B, or a solution where both A and B are satisfied simultaneously. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0041] Example 1: A method for preparing a highly stable calcium-fortified complete nutritional liquid food for special medical purposes

[0042] (1) Dissolve 1.2g resistant dextrin, 2.2g oligofructose, 0.003g carrageenan, 0.003g xanthan gum and 1.04g compound salts in 50mL of purified water to obtain the first mixture;

[0043] (2) Dissolve 5.5g casein, 10.2g maltodextrin, and 0.1g calcium carbonate in 30mL purified water to obtain a second mixture;

[0044] (3) Dissolve the mixture of 3.40g low erucic acid rapeseed oil, 0.92g medium chain triglycerides, 0.25g corn oil, and 0.02g flaxseed oil in 20mL of purified water and the compound emulsifier consisting of 0.3g soybean lecithin, 0.2g stearoyl lactate, and 0.2g sodium carboxymethyl cellulose. Perform primary emulsification by shearing (2800r / min) to obtain the oil phase.

[0045] (4) Mix the first mixture, the second mixture and the oil phase, and then add 0.2g of compound vitamins to obtain the total mixture;

[0046] (5) The total mixture was homogenized four times at 2800 r / min under 60 MPa, then bottled and sterilized at 121℃ for 15 min to obtain a highly stable calcium-fortified complete nutritional liquid food for special medical purposes.

[0047] Example 2: Preparation method of a highly stable calcium-fortified complete nutritional liquid food for special medical purposes

[0048] (1) Dissolve 1.2g resistant dextrin, 2.2g oligofructose, 0.003g carrageenan, 0.003g xanthan gum and 1.04g compound salts in 50mL of purified water to obtain the first mixture;

[0049] (2) Dissolve 5.5g casein, 10.2g maltodextrin, and 0.1g calcium carbonate in 30mL of purified water to obtain a second mixture;

[0050] (3) Dissolve the mixture of 3.40g low erucic acid rapeseed oil, 0.92g medium chain triglycerides, 0.25g corn oil, and 0.02g flaxseed oil in 20mL of purified water and the compound emulsifier consisting of 0.3g soybean lecithin, 0.2g stearoyl lactate, and 0.2g sodium carboxymethyl cellulose. Perform primary emulsification by shearing (2800r / min) to obtain the oil phase.

[0051] (4) Mix the first mixture, the second mixture and the oil phase, and then add 0.2g of compound vitamins to obtain the total mixture;

[0052] (5) The total mixture was homogenized twice at 2800 r / min under 60 MPa, then bottled and sterilized at 121℃ for 15 min to obtain a highly stable calcium-fortified complete nutritional liquid food for special medical purposes.

[0053] Example 3: Preparation method of a highly stable calcium-fortified complete nutritional liquid food for special medical purposes

[0054] (1) Dissolve 1.2g resistant dextrin, 2.2g oligofructose, 0.003g carrageenan, 0.003g xanthan gum and 1.04g compound salts in 50mL of purified water to obtain the first mixture;

[0055] (2) Dissolve 5.5g casein, 10.2g maltodextrin, and 0.1g calcium carbonate in 30mL purified water to obtain a second mixture;

[0056] (3) Dissolve the mixture of 3.40g low erucic acid rapeseed oil, 0.92g medium chain triglycerides, 0.25g corn oil, and 0.02g flaxseed oil in 20mL of purified water and the compound emulsifier consisting of 0.3g soybean lecithin, 0.2g stearoyl lactate, and 0.2g sodium carboxymethyl cellulose. Perform primary emulsification by shearing (2800r / min) to obtain the oil phase.

[0057] (4) Mix the first mixture, the second mixture and the oil phase, and then add 0.2g of compound vitamins to obtain the total mixture;

[0058] (5) The total mixture was homogenized 6 times at 2800 r / min at 60 MPa, then bottled and sterilized at 121℃ for 15 min to obtain a highly stable calcium-fortified complete nutritional liquid food for special medical purposes.

[0059] Comparative Example 1: A method for preparing a highly stable calcium-fortified complete nutritional liquid food for special medical purposes

[0060] (1) Dissolve 1.2g resistant dextrin, 2.2g oligofructose, 0.003g carrageenan, 0.003g xanthan gum and 1.04g compound salts in 50mL of purified water to obtain the first mixture;

[0061] (2) Dissolve 5.5g casein and 10.2g maltodextrin together in 30mL purified water to obtain a second mixture;

[0062] (3) Dissolve the mixture of 3.40g low erucic acid rapeseed oil, 0.92g medium chain triglycerides, 0.25g corn oil, and 0.02g flaxseed oil in 20mL of purified water and the compound emulsifier consisting of 0.3g soybean lecithin, 0.2g stearoyl lactate, and 0.2g sodium carboxymethyl cellulose. Perform primary emulsification by shearing (2800r / min) to obtain the oil phase.

[0063] (4) Mix the first mixture, the second mixture and the oil phase, and then add 0.2g of compound vitamins to obtain the total mixture;

[0064] (5) The total mixture was homogenized four times at 2800 r / min under 60 MPa, then bottled and sterilized at 121℃ for 15 min to obtain a highly stable calcium-fortified complete nutritional liquid food for special medical purposes.

[0065] Comparative Example 2: A method for preparing a highly stable calcium-fortified complete nutritional liquid food for special medical purposes

[0066] (1) Dissolve 1.2g resistant dextrin, 2.2g oligofructose, 0.003g carrageenan, 0.003g xanthan gum and 1.04g compound salts in 50mL of purified water to obtain the first mixture;

[0067] (2) Dissolve 5.5g casein, 10.2g maltodextrin, and 0.05g calcium carbonate in 30mL of purified water to obtain a second mixture;

[0068] (3) Dissolve the mixture of 3.40g low erucic acid rapeseed oil, 0.92g medium chain triglycerides, 0.25g corn oil, and 0.02g flaxseed oil in 20mL of purified water and the compound emulsifier consisting of 0.3g soybean lecithin, 0.2g stearoyl lactate, and 0.2g sodium carboxymethyl cellulose. Perform primary emulsification by shearing (2800r / min) to obtain the oil phase.

[0069] (4) Mix the first mixture, the second mixture and the oil phase, and then add 0.2g of compound vitamins to obtain the total mixture;

[0070] (5) The total mixture was homogenized four times at 2800 r / min under 60 MPa, then bottled and sterilized at 121℃ for 15 min to obtain a highly stable calcium-fortified complete nutritional liquid food for special medical purposes.

[0071] Comparative Example 3: A method for preparing a highly stable calcium-fortified complete nutritional liquid food for special medical purposes

[0072] (1) Dissolve 1.2g resistant dextrin, 2.2g oligofructose, 0.003g carrageenan, 0.003g xanthan gum and 1.04g compound salts in 50mL of purified water to obtain the first mixture;

[0073] (2) Dissolve 5.5g casein, 10.2g maltodextrin, and 0.15g calcium carbonate in 30mL purified water to obtain a second mixture;

[0074] (3) Dissolve the mixture of 3.40g low erucic acid rapeseed oil, 0.92g medium chain triglycerides, 0.25g corn oil, and 0.02g flaxseed oil in 20mL of purified water and the compound emulsifier consisting of 0.3g soybean lecithin, 0.2g stearoyl lactate, and 0.2g sodium carboxymethyl cellulose. Perform primary emulsification by shearing (2800r / min) to obtain the oil phase.

[0075] (4) Mix the first mixture, the second mixture and the oil phase, and then add 0.2g of compound vitamins to obtain the total mixture;

[0076] (5) The total mixture was homogenized four times at 2800 r / min under 60 MPa, then bottled and sterilized at 121℃ for 15 min to obtain a highly stable calcium-fortified complete nutritional liquid food for special medical purposes.

[0077] Performance testing

[0078] The performance of the highly stable calcium-fortified complete nutritional liquid special medical purpose foods prepared in Examples 1-3 and Comparative Examples 1-3 was tested, as follows:

[0079] (1) Appearance and color difference

[0080] The finished emulsion was placed at room temperature, and its color and whether layering occurred were observed. The color difference of the finished product was detected using an NR60CP+ handheld colorimeter, and the values ​​of L*, a*, and b* were recorded.

[0081] Test results are as follows Figure 1 As shown in Table 1.

[0082] Table 1 Color difference of Examples 1-3

[0083] Depend on Figure 1 As shown in Table 1, the product of Comparative Example 1, which does not contain calcium carbonate, has the darkest color (lowest L, highest a), indicating the most vigorous Maillard reaction and the formation of a large amount of brown polymer. In contrast, Examples 1-3, with the addition of appropriate amounts of calcium carbonate, have significantly whiter and more uniform colors (higher L values, lower a values), directly confirming the inhibitory effect of calcium ions on the Maillard reaction. At the same calcium addition amount, the color of Example 1 (homogenized 4 times) is better than that of Examples homogenized 2 or 6 times, indicating that the optimized homogenization process can construct a more uniform dispersion system and avoid intensified local reactions. Comparative Examples 2 and 3 show that insufficient calcium addition has a limited inhibitory effect on the Maillard reaction, while excessive homogenization or excessive calcium may damage the emulsion structure or induce ionic cross-linking, ultimately impairing the overall uniformity of the product.

[0084] (2) Grafting degree

[0085] The extent of Maillard reactions in emulsions was analyzed using the OPA method. Specifically, a certain amount of emulsion sample was taken, and an equal volume of trichloroacetic acid solution was added to precipitate proteins. The emulsion was then broken up to allow the fat to float to the surface. After high-speed centrifugation, the supernatant fat layer and TCA layer were discarded. The protein precipitate was washed with acetone to remove residual fat, and then dissolved / dispersed with an appropriate alkaline buffer (such as phosphate buffer at pH 8.0) or SDS solution to obtain a clear or homogeneous protein solution for analysis.

[0086] Test results are as follows Figure 2 It can be known that...

[0087] Depend on Figure 2It can be seen that the grafting degree of Example 1 (0.1g calcium carbonate, homogenized 4 times at 60MPa) was 43%, indicating that the Maillard reaction covalent crosslinking was most effectively inhibited; the grafting degree of Comparative Example 1 without calcium was the highest (52%), confirming the violent occurrence of the uninhibited reaction; Comparative Example 2 with insufficient calcium (47%) showed limited improvement. The grafting degree of Comparative Example 3 with excessive calcium (41%) was further reduced. Under the same calcium content, the grafting degrees of Examples 2 and 3 were slightly higher than those of Example 1, proving that the optimized homogenization process has a synergistic effect on achieving the best inhibition effect. This data corresponds completely with the aforementioned best color (highest L* value), together forming a complete chain of evidence from macroscopic manifestations to molecular mechanisms, providing a chemical basis for subsequent microstructural analysis such as emulsion particle size.

[0088] (3) 5-Hydroxymethylfurfural

[0089] The formation of Maillard reaction intermediates was determined using the measurement of 5-hydroxymethylfurfural (5-HMF). Specifically, the sample (5.0 g) was added to oxalic acid solution (0.3 mol / L, 5 mL). Trichloroacetic acid solution (40%, weight / volume, 5 mL) was added, and the mixture was shaken and allowed to stand for 15 minutes. The mixture was then centrifuged at 4000 x g for 15 minutes at room temperature. TBA (0.05 mol / L, 1 mL) was added to the supernatant, and the mixture was placed in a 40°C water bath for 30 minutes. The detection of 5-HMF was determined at 443 nm.

[0090] Test results are as follows Figure 3 It can be known that...

[0091] Depend on Figure 3 It can be seen that Example 1 (0.1g calcium carbonate, homogenized 4 times at 60MPa) had the lowest 5-hydroxymethylfurfural content (21.2%), indicating that the Maillard reaction chain was effectively inhibited in the middle stage. Comparative Example 1 (no calcium) had the highest content (26.0%), confirming the vigorous progress of the uninhibited reaction; Comparative Example 2 (calcium deficiency) had a lower content (24.8%), but the inhibition was still insufficient. Comparative Example 3 (calcium excess) had the lowest content (20.8%), further enhancing the inhibition effect. Under the same calcium content, the contents of Examples 2 and 3 were slightly higher than those of Example 1, also demonstrating that the optimal homogenization process has a synergistic effect on achieving comprehensive inhibition.

[0092] (4) Melanoid content

[0093] The production of the final product of the Maillard reaction was determined by measuring the content of melanoidins. Specifically, a certain amount of emulsion sample was taken, and an equal volume of trichloroacetic acid solution was added to precipitate proteins, followed by demulsification to allow the fat to float. After high-speed centrifugation, the supernatant fat layer and TCA layer were discarded. The protein precipitate was washed with acetone to remove residual fat, and then dissolved / dispersed with an appropriate alkaline buffer (such as phosphate buffer at pH 8.0) or SDS solution to obtain a clear or homogeneous protein solution for analysis. The absorbance at 470 nm was measured using a UV-Vis spectrophotometer, and calculations were performed using the Lambert-Beer law equation.

[0094] Test results are as follows Figure 4 It can be known that...

[0095] As Figure 4 It can be seen that Example 1 (0.1g calcium carbonate, homogenized 4 times at 60MPa) had the lowest content (0.055 mmol / L), indicating that the least amount of final reaction product was generated. Comparative Example 1 (no calcium) had the highest content (0.112 mmol / L), directly confirming that the reaction was not completely inhibited; the content of Comparative Example 2 (calcium deficiency) (0.073 mmol / L) decreased but was still relatively high, indicating insufficient inhibition. The content of Comparative Example 3 (calcium excess) (0.053 mmol / L) was slightly lower than that of Example 1. The contents of Examples 2 and 3 were higher than those of Example 1, further demonstrating the necessity of the synergistic effect of the homogenization process. This data is closely related to the color difference, grafting degree, and 5-hydroxymethylfurfural index, fully demonstrating that only under the synergistic effect of the optimal calcium concentration (approximately 0.1g) and the optimal process (60MPa / 4 times) can the entire Maillard reaction be effectively inhibited while ensuring the physical stability of the system.

[0096] (5) Emulsion particle size

[0097] The particle size of the finished emulsion was measured using a laser particle size distribution analyzer. Specifically, the finished emulsion sample was diluted 200 times with deionized water before measurement. The main instrument parameters were set as follows: particle refractive index 1.414, absorption index 0.001, aqueous phase refractive index 1.330, and absorption index 0.

[0098] Test results are as follows Figure 5 It can be known that...

[0099] Depend on Figure 5It can be seen that Example 1 (0.1g calcium carbonate, homogenized 4 times at 60MPa) has the smallest particle size (484 nm), indicating that it formed the finest and most stable colloidal system. Comparative Example 1, without calcium, has the largest particle size (766 nm), confirming that the Maillard reaction generates a large amount of polymer. Comparative Example 2 (592 nm), with insufficient calcium, has a limited inhibitory effect, while Comparative Example 3 (675 nm), with excessive calcium, although calcium continues to inhibit the Maillard reaction, calcium ions aggregate through ionic cross-linking. Under the same formulation, the particle size of homogenized 2 or 6 times (Examples 2 and 3) is larger than that of homogenized 4 times, proving that this process parameter is crucial for constructing the optimal particle structure. The particle size results indicate that this invention, by precisely controlling the calcium content (approximately 0.1g) and the homogenization process (60MPa / 4 times), achieves a balance between inhibiting the Maillard reaction and avoiding excessive ionic cross-linking, thereby obtaining a microscopically uniform and macroscopically stable high-calcium liquid product.

[0100] (6) Cryo-scanning electron microscopy

[0101] The microstructure of the finished medical sample was observed using an S-3000 cryo-scanning model. Specifically, the sample was placed in an aluminum can and rapidly frozen in liquid nitrogen (-90°C for 10 min). Then, in a vacuum cryogenic fracture chamber, the sample was cut with the edge of a scalpel to expose its cross-section. The sample was placed in a freezing stage, and its microstructure was observed via a cryo-transport system.

[0102] Test results are as follows Figure 6 It can be known that...

[0103] Depend on Figure 6 It can be seen that Example 1 (0.1g calcium carbonate, homogenized 4 times at 60MPa) exhibits a uniform and dense three-dimensional gel network, with fat and protein particles fully fixed and structurally intact. Comparative Example 1, without calcium, shows a large number of coarse polymer aggregates, a direct representation of Maillard reaction products. Comparative Example 2, with insufficient calcium, has a loose network and insufficient inhibition effect. Comparative Example 3, with excessive calcium, shows locally dense and rigid clumps, due to excessive calcium ion cross-linking. Under the same formulation, the structural uniformity of Example 2 or Example 3 is less than that of homogenized 4 times. This demonstrates that the present invention, through precise control of calcium content and homogenization process, synergistically inhibits the formation of harmful polymers and avoids excessive ionic cross-linking at the molecular level. This is consistent with the aforementioned changes in emulsion particle size.

[0104] (7) Centrifugal sedimentation rate

[0105] The centrifugal sedimentation rate of the finished emulsion is measured to express its centrifugal stability. 50g of sample is poured into a centrifuge tube and centrifuged at 3000 r / min for 15 min using a TD-5M benchtop low-speed centrifuge. The centrifugal sedimentation rate of the sample is then calculated.

[0106] Test results are as follows Figure 7 It can be known that...

[0107] Depend on Figure 7 It can be seen that Example 1 (0.1g calcium carbonate, homogenized 4 times at 60MPa) had the lowest sedimentation rate, indicating that it had the strongest resistance to phase separation. Comparative Example 1 without calcium had the highest sedimentation rate (3.35%), which, along with the worst color and largest particle size, confirmed that the uninhibited Maillard reaction severely damaged stability. Comparative Example 2 with insufficient calcium showed limited improvement, while the sedimentation rate of Comparative Example 3 with excessive calcium rose sharply. Although calcium ions continuously inhibited the Maillard reaction, the excessive calcium ion content caused harmful cross-linking. Under the same formulation, the sedimentation rates of Examples 2 and 3 were higher than those of Example 1, which again proves that the process parameters are crucial for maintaining long-term stability.

[0108] (8) Viscosity

[0109] The apparent viscosity of the finished emulsion was measured using a rotational dynamic shear rheometer. Specifically, the sample was placed on a platform, and the shear rate ranged from 0.1 s to 100 s. −1 The apparent viscosity of a sample is determined by measuring its response to different shear rates.

[0110] Test results are as follows Figure 8 It can be known that...

[0111] Depend on Figure 8 As can be seen, Example 1 exhibits the lowest viscosity at all shear rates, demonstrating ideal low viscosity and good shear-thinning properties. Comparative Example 1 (calcium-free) has the highest viscosity due to the formation of a large amount of polymer via the Maillard reaction, while Comparative Example 3 (calcium excess) shows a significant increase in viscosity due to excessive ionic crosslinking; both impair rheological applicability. Comparative Example 2 (calcium deficiency) shows an intermediate viscosity with limited improvement. Under the same formulation, the viscosities of Examples 2 and 3 are both higher than that of Example 1, further verifying the crucial role of these process parameters in constructing suitable fluid structures.

[0112] (9) Stability Analysis

[0113] Multiple light scattering of the finished emulsion was measured to assess its stability. Specifically, a dispersion stability analyzer was used to evaluate the emulsion stability. The parameters were configured as follows: scan time of 3 hours, scan interval of 2 minutes, and test temperature of 30°C. The analysis software provided Delta backscattering (ΔBS) and Turbiscan stability index (TSI).

[0114] Test results are as follows Figure 9 It can be known that...

[0115] Depend on Figure 9It can be seen that Example 1 exhibits the highest Delta backscattering (ΔBS) overlap and the lowest Turbiscan stability index (TSI), indicating that no detectable particle migration, aggregation, or phase separation occurred in this sample, making the emulsion system the most stable. Comparative Example 1 (calcium-free) shows the most dramatic change in its ΔBS curve, the highest TSI value, and the fastest increase, directly reflecting the rapid aggregation and phase separation caused by the uninhibited Maillard reaction. Comparative Example 2 (calcium-deficient) shows improved stability but remains insufficient. Comparative Example 3 (calcium-excessive) exhibits a continuous risk of instability due to excessive ionic crosslinking. Examples 2 and 3, deviating from the optimal number of homogenization cycles under the same formulation, show lower dynamic stability than Example 1. These dynamic monitoring results corroborate all previous static characterization data, jointly confirming that precisely controlling the calcium carbonate content to approximately 0.1g and employing a "60MPa homogenization four times" process can synergistically inhibit the Maillard reaction and excessive ionic crosslinking at the kinetic level, thereby endowing the product with excellent long-term storage stability.

[0116] In summary, this invention systematically solves the stability problem of high-calcium liquid medical foods through precise design of formulation components and synergistic optimization of key processing techniques. The core technology lies in precisely controlling the amount of calcium carbonate added, ensuring that at a specific concentration, it can bind with casein, effectively inhibiting the Maillard reaction between casein and maltodextrin during high-temperature sterilization (directly confirmed by grafting degree, 5-hydroxymethylfurfural, and melanoidin content), improving color and flavor, while avoiding harmful protein cross-linking caused by excessive calcium ions. Simultaneously, the specific process of high-pressure homogenization (60 MPa, 4 times) thoroughly breaks down and mixes the oil phase, protein, and colloidal components, forming uniformly sized, densely structured micro-droplets, thus constructing a stable structure at the microscale that resists aggregation and phase separation. The synergy between this "precise formulation" and "optimized homogenization process" ultimately enables the product to achieve high calcium nutritional fortification while also possessing excellent processing tolerance, long-term storage stability, and good clinical applicability.

[0117] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly stable calcium-fortified complete nutritional liquid food for special medical purposes, characterized in that it comprises the following components in the indicated mass concentrations: casein 5-6 g / 100 mL, maltodextrin 10-11 g / 100 mL, mixed oil 4-5 g / 100 mL, resistant dextrin 1-2 g / 100 mL, fructooligosaccharides 2-3 g / 100 mL, compound emulsifier 0.3-0.5 g / 100 mL, phospholipids 0.2-0.4 g / 100 mL, calcium carbonate 0-0.2 g / 100 mL, compound vitamins 0.1-0.3 g / 100 mL, compound salts 1-2 g / 100 mL, xanthan gum 0.002-0.004 g / 100 mL, carrageenan 0.002-0.004 g / 100 mL, edible flavoring 0.1-0.2 g / 100 mL, and purified water 70-80 g / 100 mL.

2. The highly stable calcium-fortified complete nutritional liquid food for special medical purposes as described in claim 1, characterized in that it comprises the following components in the following mass concentrations: casein 5.5g / 100mL, maltodextrin 10.2g / 100mL, mixed oil 4.6g / 100mL, resistant dextrin 1.2g / 100mL, fructooligosaccharides 2.2g / 100mL, compound emulsifier 0.4g / 100mL, phospholipid 0.3g / 100mL, calcium carbonate 0.1g / 100mL, compound vitamins 0.2g / 100mL, compound salt 1.04g / 100mL, xanthan gum 0.003g / 100mL, carrageenan 0.003g / 100mL, edible flavor 0.11g / 100mL, and purified water 75g / 100mL.

3. The highly stable calcium-fortified complete nutritional liquid food for special medical purposes as described in claim 1, characterized in that the mixed oils include low-erucic acid rapeseed oil, medium-chain triglycerides, corn oil, and flaxseed oil.

4. The highly stable calcium-fortified complete nutritional liquid special medical purpose food as described in claim 3, characterized in that the mass percentages of the low erucic acid rapeseed oil, medium-chain triglycerides, corn oil, and flaxseed oil are 74%, 20%, 5.5%, and 0.5%, respectively.

5. The highly stable calcium-fortified complete nutritional liquid food for special medical purposes as described in claim 1, characterized in that the compound emulsifier comprises at least two of stearoyl lactate, sodium carboxymethyl cellulose, and gelatin; and / or, The compound vitamins include vitamin A, vitamin D, vitamin E, vitamin K1, vitamin B1, vitamin B2, vitamin B6, vitamin B12, niacin, folic acid, pantothenic acid, vitamin C, and biotin; and / or, The compound salt includes sodium chloride, potassium chloride, sodium hexametaphosphate, and sodium metaphosphate.

6. A method for preparing a highly stable calcium-fortified complete nutritional liquid food for special medical purposes as described in claim 1, characterized in that, Includes the following steps: Step A: Dissolve resistant dextrin, fructooligosaccharides, xanthan gum, carrageenan, and salts together with purified water to obtain the first mixture; Step B: Dissolve casein, maltodextrin, and calcium carbonate together with purified water to obtain a second mixture; Step C: Dissolve corn oil, low-erucic acid rapeseed oil, medium-chain triglycerides, flaxseed oil, phospholipids, and compound emulsifier in purified water and perform primary emulsification by shearing to obtain the oil phase; Step D: Mix the first mixture, the second mixture, and the oil phase, then add the compound vitamins to obtain the total mixture; Step E: Homogenize the total mixture, then bottle and sterilize it to obtain a highly stable calcium-fortified complete nutritional liquid food for special medical purposes.

7. The method for preparing the highly stable calcium-fortified complete nutritional liquid food for special medical purposes as described in claim 6, characterized in that, In step C, the shearing rate is 2700–2900 r / min.

8. The method for preparing the highly stable calcium-fortified complete nutritional liquid food for special medical purposes as described in claim 6, characterized in that, in step E, the pressure of the homogenization treatment is 50-70 MPa; and / or, the number of homogenization treatments is 3-5 times.

9. The method for preparing the highly stable calcium-fortified complete nutritional liquid food for special medical purposes as described in claim 6, characterized in that, in step E, the sterilization temperature is 120-125°C.

10. The method for preparing the highly stable calcium-fortified complete nutritional liquid food for special medical purposes as described in claim 6, characterized in that, in step E, the sterilization time is 13-17 min.

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