Wheat-resistant dextrin-containing total nutrient powder for old people and preparation method of wheat-resistant dextrin-containing total nutrient powder

Abstract

The invention provides wheat-resistant-dextrin-containing total nutrient powder for old people, which comprises the following components in parts by mass: 25-45 parts of solid corn syrup, 5-30 parts of starch-based resistant dextrin, 10-20 parts of protein, 10-12 parts of vegetable fat powder, 8-12 parts of maltodextrin, 0-0.3 part of ellagic acid and 5-8 parts of maltitol. 1-2 parts of medium chain triglyceride, 0.1-0.5 part of DHA powder, 1-5 parts of composite mineral substances and 1-3 parts of composite vitamins. The invention further provides a preparation method of the all-nutrition powder for the old people. The full-nutrition powder for old people provided by the invention has the advantages that the brewing performance is obviously improved, the moisture-proof stability is enhanced, and the full-nutrition powder has excellent anti-digestion performance and high protein digestibility.

Description

Technical Field

[0001] This invention belongs to the field of functional food technology, specifically relating to a complete nutritional powder for the elderly and its preparation process. Background Technology

[0002] With the increasing aging of the population, the demand for complete nutritional supplements among the elderly is growing, and related nutritional products are constantly being updated. Currently, most nutritional powders for the elderly on the market focus on basic nutritional ratios. For example, patent CN103300282A proposes a nutritional powder for the elderly containing soybean oligopeptides and its preparation method. This powder uses soybean oligopeptides as the main nutrient, and adds 45-75 parts of wheat flour, rice flour, or corn flour (one or more), 10-30 parts of oat flour, buckwheat flour, or Job's tears flour (one or more), 3-5 parts of vegetable oil, and 5-7 parts of fruit and vegetable powder. The carbohydrates in the aforementioned nutritional powders, such as wheat flour, rice flour, or corn flour, can cause fluctuations in blood sugar, which can have adverse effects on the elderly and those with disorders of glucose and lipid metabolism.

[0003] These are common defects of existing nutritional powders: (1) Poor reconstitution: Some high-protein complete nutritional powders are prone to clumping when reconstituted, and the dispersion speed is slow, which affects the user experience of the elderly.

[0004] (2) Fast digestion: The starch in conventional complete nutritional powder is easily digested quickly, which is not friendly to the elderly who need to stabilize their blood sugar levels. (3) Insufficient stability: It is prone to moisture and clumping during long-term storage.

[0005] Resistant dextrin is a low-calorie dextran produced by processing starch. It is created by industrially extracting and refining the indigestible components of roasted dextrin. However, resistant dextrins from different starch sources have different effects. For example, corn resistant dextrin (CZAPI) is a low-molecular-weight water-soluble dietary fiber prepared from corn starch through a modification process. CZAPI can bind to some digestive proteases to form stable complexes, thereby protecting vitamins, nucleic acids, palmitic acid, and other substances from inefficient decomposition by digestive enzymes. Therefore, corn resistant dextrin can be used in food additives, slow-release agents for poorly soluble drugs, and bioreactors, playing a role in protecting and assisting other substances. Wheat resistant dextrin (Wheat Amylase Trypsin Inhibitors, ATI) is also a low-molecular-weight water-soluble dietary fiber that can inhibit the activity of wheat amylase, thereby slowing down the digestion of starch and allowing carbohydrates in wheat to be released gradually, helping to maintain blood sugar levels for a longer period of time. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the first objective of this invention is to provide a complete nutritional powder for the elderly containing wheat resistant dextrin, which significantly improves dispersibility, reduces caking rate, and significantly increases resistant starch (RS) content while decreasing the proportion of rapidly digestible starch (RDS). This meets the nutritional needs of special populations such as the elderly and those with disorders of glucose and lipid metabolism.

[0007] The second objective of this invention is to provide a method for preparing the aforementioned complete nutritional powder for the elderly.

[0008] The technical solution for achieving the above-mentioned objective of this invention is as follows: A complete nutritional powder for seniors containing wheat resistant dextrin comprises the following ingredients in parts by weight: Solid corn syrup 25-45 parts, starch-based resistant dextrin 5-30 parts, protein 10-20 parts, vegetable fat powder 10-12 parts, maltodextrin 8-12 parts, ellagic acid 0-0.3 parts, maltitol 5-8 parts, medium-chain triglycerides 1-2 parts, DHA powder 0.1-0.5 parts, complex minerals 1-5 parts, and complex vitamins 1-3 parts.

[0009] This complete nutritional powder contains resistant dextrin, along with maltodextrin and solid corn syrup. The combination of these with resistant dextrin achieves a "fast-slow" energy balance, prolonging satiety and stabilizing blood sugar. Furthermore, this technology utilizes the excellent film-forming and anti-caking properties of maltodextrin and solid corn syrup as carriers in dry mixing, improving particle agglomeration caused by a high proportion of resistant dextrin and enhancing powder flowability and reconstitution. Maltodextrin, characterized by high sweetness, high solubility, and low viscosity, is also an easily absorbed carbohydrate. Adding it to the complete nutritional powder provides energy and improves taste and sweetness. Due to its good hygroscopic and anti-caking properties, maltodextrin also significantly improves the powder's water solubility, flowability, and suspension properties, preventing clumping, improving mouthfeel, and making the complete nutritional powder easier to prepare and drink.

[0010] The starch-based resistant dextrin is wheat starch resistant dextrin, and the dosage is 15-25 parts.

[0011] Among starch-based resistant dextrins, wheat-based resistant dextrin is preferred over corn / potato-based resistant dextrin because it has a lower gelatinization temperature, protecting heat-sensitive nutrients; lower crystallinity, preventing a "gritty" texture or difficulty in dissolving after cooling; and extremely low in vitro hydrolysis rate (<2%), effectively delaying the rise in blood sugar. Furthermore, it significantly promotes the growth of beneficial bacteria such as butyric acid-producing bacteria, maintaining colon health—a benefit not found in corn / potato-based sources.

[0012] Compared to oligosaccharides, wheat resistant dextrin has a more significant regulatory effect on blood glucose and blood lipids, slowing down the rate and peak of blood glucose rise, improving glucose metabolism, and helping to alleviate health problems such as obesity and diabetes. Studies have shown that wheat resistant dextrin can stimulate intestinal peristalsis and accelerate metabolism; it also produces short-chain fatty acids through intestinal flora fermentation, activates hepatic lipid metabolism radicals, reduces the expression of lipid synthesis genes, and regulates metabolic homeostasis. Oligosaccharides have a weaker effect in this regard, but are more effective in improving constipation and promoting intestinal peristalsis.

[0013] The protein is composed of 10-15 parts whey protein and 3-5 parts walnut protein; and the ellagic acid is 0.1-0.3 parts.

[0014] This nutritional powder uses walnut protein as its protein source because it is rich in arginine (a precursor to vasodilation), aspartic acid, and glutamic acid (brain-boosting substances), and its amino acid profile closely resembles the FAO standard. Its lysine to arginine ratio is extremely low (0.16~0.19), effectively preventing coronary heart disease and atherosclerosis, making it particularly suitable for the elderly. Furthermore, walnut protein boasts a high digestibility and absorption rate of 87.2%, superior to wheat protein (61.44%), and contains no components that cause gluten intolerance. Walnut protein can form stable nanocomplexes with polyphenols (such as ellagic acid) through non-covalent interactions, achieving an "encapsulation" effect.

[0015] Experiments revealed that walnut protein has poor solubility, and the addition of ellagic acid (EA) improved its solubility. Furthermore, as a potent antioxidant, EA can cross-link with protein side chains to prevent oxidative aggregation (caking) during storage and protect proteins from gastric acid damage. It can also scavenge free radicals, chelate metal ions, reduce the burden on the liver and kidneys in the elderly, and delay cellular aging. By inhibiting insulin resistance caused by the inflammatory factor TNF-α, it restores the insulin signaling pathway, promotes GLUT4 expression to improve glucose uptake efficiency, and stabilizes blood sugar levels.

[0016] Preferably, the complete nutritional powder for the elderly containing wheat resistant dextrin comprises the following components in parts by weight: The ingredients are: 25 parts solid corn syrup, 25 parts wheat resistant dextrin, 12 parts whey protein, 12 parts vegetable fat powder, 10 parts maltodextrin, 4 parts walnut protein, 0.1-0.3 parts ellagic acid, 6 parts maltitol, 1.2 parts medium-chain triglycerides, 0.3 parts DHA powder, 3 parts compound minerals, and 2 parts compound vitamins.

[0017] Based on the study of the properties of various components of the nutritional powder, this invention proposes a method for preparing the aforementioned complete nutritional powder for the elderly, comprising the following steps: (1) Preparation of wet-mixed raw materials: Disperse walnut protein in water and adjust the pH of the resulting walnut protein dispersion to 8-10. Prepare an ellagic acid solution with a mass concentration of 0.2-1%, and mix the walnut protein solution and the ellagic acid solution to obtain a walnut protein-ellagic acid complex; Whey protein and maltitol were mixed with the walnut protein-ellagic acid complex to prepare a wet-mixed raw material solution, which was then freeze-dried into a powder. (2) Dry mixing: Weigh the corresponding mass of solid corn syrup, wheat resistant dextrin, vegetable fat powder, maltodextrin, medium chain triglyceride powder, DHA powder, compound minerals and compound vitamins according to the formula of wheat resistant dextrin whole nutrition powder. Premix the above raw materials in a vortex mixer for 15 min, then add the powder obtained by wet mixing, and continue mixing for 20 min to obtain the finished whole nutrition powder.

[0018] In step (1), walnut protein is dispersed in water, the pH of the walnut protein dispersion is adjusted to 9.0, and the mixture is stirred for 0.5-2 hours. The pH of the ellagic acid solution is then adjusted to 9.0. The walnut protein solution and the ellagic acid solution are mixed, and the mixture is stirred at room temperature while maintaining the pH at 9.0 for 1-2 hours. The pH can be adjusted using NaOH solution or an alkaline solution known in the art.

[0019] The walnut protein solution and ellagic acid solution were mixed, and the mixture was stirred at room temperature for 90 min while maintaining the pH at 9.0. The pH of the mixture was then adjusted to 7.0 to obtain the walnut protein-ellagic acid complex.

[0020] In step (1), whey protein and maltitol are prepared into a solution with a total mass concentration of 10-15% under water bath conditions of 35-45℃ (total mass refers to the sum of the masses of whey protein and maltitol).

[0021] One of the preferred technical solutions of the present invention is that, in step (1), the ratio of the total content of the wet-mixed raw materials to water is 4~6%. A more preferred ratio is 4.12%~5.50% (the total content of the raw materials refers to the ratio of the raw materials to water during the wet mixing process, and the water content is 0 after drying).

[0022] In step (2), the remaining raw materials are premixed in a vortex mixer for 15 minutes, and then the material obtained by wet mixing is added and mixed for another 20 minutes to obtain the finished product of the complete nutrient powder.

[0023] The beneficial effects of this invention are as follows: The complete nutritional powder for the elderly proposed in this invention, (1) Significantly improved reconstitution performance: The addition of wheat resistant dextrin significantly shortened the dispersion time and wetting time. Among them, the high addition group had the shortest dispersion time, indicating the best dispersion performance.

[0024] (2) Enhanced moisture resistance and stability: The clumping rate decreases significantly with the increase of resistant dextrin addition, which helps the product to be stored for a long time.

[0025] (3) Excellent anti-digestion properties: Resistant dextrin can significantly reduce the RDS ratio and make the RS content proportional to the amount added, which helps to slow down the rate of postprandial blood glucose rise in the elderly.

[0026] (4) High protein digestibility: Despite the addition of functional ingredients, the final protein digestibility of all groups in simulated digestion of the elderly remained at a high level of 80% to 90%.

[0027] This invention studies the effects of wheat starch-based resistant dextrin and other ingredient additions on the powder's reconstitution characteristics, beverage stability, and noodle product texture. It establishes a method for preparing nutritional powder through dry-wet mixing, multi-component solubilization, and multi-interface emulsification, resulting in solid powders with excellent taste and flavor and high product stability, meeting the nutritional needs of special populations such as the elderly and those with disorders of glucose and lipid metabolism. Attached Figure Description

[0028] Figure 1 This is a graph showing the effect of total ingredient content on particle size. Figure 2 This is a graph showing the effect of changes in the ratio of whey protein to walnut protein on particle size. Figure 3 This is a graph showing the effect of magnetic stirring temperature on particle size. Figure 4 This is a graph showing the effect of total ingredient content on centrifugal sedimentation rate. Figure 5 The graph shows the effect of the ratio of whey protein to walnut protein on the centrifugal sedimentation rate. Figure 6 The graph shows the effect of magnetic stirring temperature on centrifugal sedimentation rate.

[0029] Figure 7 Average particle size distribution of the three groups of samples prepared under optimal conditions.

[0030] Figure 8 The distribution of centrifugation sedimentation rate of the three sets of samples prepared for replication.

[0031] Figure 9 This is a comparison chart of the dispersibility of the control and Example 3, 4, and 5 samples; Figure 10 This is a comparison graph showing the solubility of the control and Example 3, 4, and 5 samples; Figure 11 This is a comparison chart of the agglomeration rate of the control and Example 3, 4, and 5 samples; Figure 12This is a comparison chart of the wettability of the control and Example 3, 4, and 5 samples; Figure 13 DSC curves for the control and Example 3, 4, and 5 samples; Figure 14 This is a comparison chart of particle size of the control and Example 3, 4, and 5 samples; Figure 15 A comparison diagram of gastric phase protein digestibility dispersion of control and Example 3, 4, and 5 samples; Figure 16 A graph showing the comparison of protein digestibility between the control and samples from Examples 3, 4, and 5; Figure 17 This is a comparison chart of rapidly digestible starch in control and Example 3, 4, and 5 samples; Figure 18 A comparison graph showing the slow-digested starch (SDS) of the control and Example 3, 4, and 5 samples; Figure 19 This is a comparison chart of resistant starch in control and Example 3, 4, and 5 samples. Detailed Implementation

[0032] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention.

[0033] Unless otherwise specified, all technical methods used in this instruction manual are known in the art, and all raw materials used are commercially available. The table below lists the sources of the main raw materials.

[0034] Example 1: Solubility determination of each ingredient in the complete nutritional powder Weigh 5g of raw material powder into a beaker, add 45mL of water at 60℃, stir with a glass rod for 30s to form a uniform suspension, let stand for 5min, take a picture to observe its solubility, and combine the solubility test results with the heat sensitivity of the raw materials to determine whether each raw material should be added in the wet or dry mixing part.

[0035] 1) Walnut protein solubility determination: The results showed that when the walnut protein solution had a pH of 9, there was less precipitation and better solubility. Therefore, during wet mixing, walnut protein powder was added using a wet mixing method, and the pH was adjusted to 9. The nitrogen solubility indices of walnut protein isolate and walnut protein concentrate were 29.06% and 28.24%, respectively, indicating that walnut protein itself has poor solubility. Literature review revealed that the isoelectric point of walnut protein is 5, and high-speed shearing can improve its solubility. Therefore, by adjusting the pH of the walnut protein solution to 7, 8, and 9 and observing the solubility, the pH with the best solubility was selected for wet mixing, and high-speed shearing at 12000 r / min for 3 min was applied to further improve the solubility.

[0036] 2) Maltitol solubility: Observations show that maltitol has good solubility in water and no precipitation occurs after standing. Adding maltitol to the wet mixing stage of the production of complete nutrient powder helps to form a weaker gel network, reduces the hardness of the system, and makes the dried powder obtained by freeze-drying exhibit better looseness and flowability. Therefore, maltitol is added in the wet mixing stage.

[0037] 3) Whey protein solubility: Whey protein dissolves in water to form an opaque turbid liquid, but no precipitate forms after standing, indicating good solubility. Since the isoelectric point of whey protein is 4.8, adjusting the solution pH to 9 also facilitates whey protein dissolution. Furthermore, the ratio of whey protein to walnut protein has a significant impact on the particle size of the wet-mixed solution. To facilitate adjustment of the whey protein to walnut protein ratio, whey protein is added during the wet mixing process.

[0038] 4) Solubility of multivitamins: Observation shows that a small amount of sediment forms at the bottom of the multivitamin after standing, indicating good solubility in water. Since multivitamins contain heat-sensitive nutrients such as vitamin C that are easily lost through water dissolution, and fat-soluble vitamins such as vitamin A, they are added during the dry mixing process.

[0039] 5) The five raw materials, namely vegetable fat powder, medium-chain triglycerides, wheat resistant dextrin, maltodextrin, and solid corn syrup, dissolved in water and allowed to stand, formed a solution with no precipitate at the bottom, indicating good solubility. Therefore, they were added to the dry mixing section.

[0040] 6) Solubility of compound minerals: Observations show that after the compound minerals are dissolved in water and left to stand, a precipitate forms at the bottom of the solution, indicating poor solubility of the compound minerals. However, in a solution with pH=9 and requiring high-speed shearing, high-speed shearing can easily lead to local concentration fluctuations. The mineral ions dissolved by high-speed shearing are easily reprecipitated as hydroxides, forming a new solid phase that adheres to the surface of the mineral particles, further reducing the effective solubility and failing to effectively increase the solubility of the compound minerals. Furthermore, the amount of compound minerals added to the complete nutrient powder is relatively small, so it is added in the dry mixing section. Example 2

[0041] This embodiment optimizes process conditions through single-factor experiments.

[0042] In the wet mixing stage, the appropriate raw materials were weighed and then added to a water bath at a certain temperature with magnetic stirring. After adding the raw materials, the mixture was magnetically stirred for 30 minutes for premixing, followed by high-speed shearing at 12000 rpm for 3 minutes. The particle size of the solution after shearing was measured using a laser particle size analyzer. This section first conducted single-factor experiments to determine the total ingredient content, whey protein to walnut protein ratio, and magnetic stirring temperature of the wet-mixed sample, using particle size and centrifugal sedimentation rate as single-factor experimental indicators.

[0043] Single-factor experiments were conducted to determine the effects of total ingredient content, whey protein to walnut protein ratio, and magnetic stirring temperature on sample particle size. 1) Single-factor experiment on the effect of total ingredient content on particle size during wet mixing stage With a fixed ratio of walnut protein powder to whey protein of 3:5, a premixed water bath temperature of 60℃, and 3g of maltitol added, the solution pH was adjusted to 9. The particle size of the solution was investigated at total ingredient content in water during the wet mixing stage when it was 1.38%, 2.75%, 4.12%, 5.50%, and 6.88%. The group with the smallest particle size and the highest data parallelism was determined as the optimal total ingredient content. The water addition amounts for the total ingredient contents of 1.38%, 2.75%, 4.12%, 5.50%, and 6.88% were 1000ml, 400ml, 267ml, 200ml, and 160ml, respectively (total ingredient content refers to the ratio of raw materials to water during wet mixing; water content is 0% after drying). The water addition amount during the wet mixing process was calculated based on the total protein content. Because walnut protein is poorly soluble in water, different water addition amounts were set to observe the optimal total protein content for dissolution.

[0044] The results of the single-factor experiment on the effect of total ingredient content on particle size are shown below. Figure 1 The results showed that the average particle size of the samples was larger when the total ingredient content was too high or too low. The average particle size decreased slightly when the total ingredient content was 2.75%, but remained relatively high. The samples with the best average particle size were those with total ingredient contents of 4.12% and 5.50%. The reasons for this are speculated to be as follows: at the lowest total ingredient content of 1.38%, the dispersed phase molecules were too far apart and their interactions were weak, failing to form stable, fine particles, resulting in localized aggregation and loose particle size. At a total ingredient content of 2.75%, the concentration was moderate, and the dispersed phase began to form a uniform network, improving dispersibility, but the aggregation state remained relatively loose. At total ingredient contents of 4.12% and 5.50%, the concentration was sufficient, allowing the dispersed phase molecules to fully contact each other, forming a dense and stable dispersion system, and the particles were fully broken down, resulting in a smaller average particle size. At a total ingredient content of 6.88%, the concentration was too high, the dispersed phase molecules were too crowded, and non-covalent bonds promoted particle aggregation, leading to an increase in average particle size.

[0045] 2) Single-factor experiment on the effect of whey protein to walnut protein ratio on particle size The experiment found that the optimal solution particle size (minimum average particle size (D[4,3])) was achieved when the total ingredient content was 4.12%. Therefore, with the total ingredient content fixed at 4.12%, the premixed water bath temperature at 60℃, and the maltitol addition at 3g, the solution pH was adjusted to 9. The particle size of the solutions with walnut protein powder and whey protein ratios of 8:0, 2:6, 2.5:5.5, 3:5, 3.5:4.5, 4:4, and 0:8 were investigated. The group with the smallest particle size and the highest data parallelism was determined to be the optimal protein source ratio.

[0046] 3) Single-factor experiment on the effect of changes in the ratio of whey protein to walnut protein on particle size: The total ingredient content was fixed at 4.12%, and the temperature was 60℃.

[0047] Figure 2 The results showed that, under the conditions of a total ingredient content of 4.12% and a temperature of 60℃, the ratio of whey protein to walnut protein had a significant impact on the average particle size of the samples: when the ratio was 8:0 (pure whey protein) or 0:8 (pure walnut protein), the average particle size of the samples was higher, while when the ratio deviated from the pure components (such as 6:2, 4.5:2.5, 4:4), the average particle size decreased significantly. Among them, the particle size of the samples with ratios of 5.5:3.5 and 5:3 returned to the level of the pure components. The significance analysis between groups also confirmed this difference. The reason for this phenomenon is speculated to be that in pure whey protein or pure walnut protein systems, the aggregation behavior of single protein molecules is relatively strong, and they are prone to forming aggregates with larger particle sizes. However, when the two proteins are combined, the intermolecular interactions between whey protein and walnut protein (such as electrostatic interactions and hydrophobic interactions) can inhibit the excessive aggregation of single proteins, thereby reducing the particle size. But when the ratio is in the range of 5.5:3.5 to 5:3, the ratio of the two proteins approaches a specific interaction equilibrium point, the intermolecular binding mode changes, the aggregate size increases again, and finally exhibits the above particle size distribution characteristics.

[0048] 4) Single-factor experiment on the effect of magnetic stirring temperature on particle size: The total ingredient content was fixed at 4.12%, the amount of maltitol added was 3g, and the protein source was the optimal ratio determined in the experiment, that is, the ratio of whey protein to walnut protein was 6:2. The pH of the solution was adjusted to 9, and the particle size of the solution at water bath temperatures of 40℃, 50℃ and 60℃ were investigated respectively. The group with the smallest particle size and the highest data parallelism was determined as the optimal premixing water bath temperature.

[0049] See results Figure 3Under the conditions of a fixed whey protein to walnut protein ratio of 6:2 and a total ingredient content of 4.12%, temperature showed a significant positive regulatory effect on the average particle size of the samples: the average particle size was smallest at 40℃; the particle size increased significantly at 50℃; and at 60℃, the particle size further increased to over 50 μm. The significant markers (a, b, c) between the groups clearly indicated the differences between the temperature groups. The reason for this result may be that at lower temperatures, the thermal motion of protein molecules is weak, the driving force for intermolecular aggregation is insufficient, and the system is dominated by small dispersed particles; as the temperature increases, the thermal motion of molecules intensifies, the exposure of hydrophobic groups of protein molecules increases, the balance between intermolecular hydrophobic interactions and electrostatic interactions is broken, and the formation and growth of protein aggregates are promoted; when the temperature rises to 60℃, the conformational unfolding of protein molecules is further enhanced, more active groups participate in intermolecular binding, and ultimately the aggregate size increases significantly, showing the characteristic of increasing particle size with increasing temperature.

[0050] 5) Single-factor experiments were conducted to determine the effects of total ingredient content, whey protein to walnut protein ratio, and magnetic stirring temperature on the centrifugal sedimentation rate of the samples. Single-factor experiment to investigate the effect of total ingredient content on centrifugal sedimentation rate: 10 mL of solutions with total ingredient contents of 1.38%, 2.75%, 4.12%, 5.50%, and 6.88% were taken from centrifuge tubes, and the sample mass m0 was measured. The tubes were then centrifuged at 4000 r / min for 10 min. After removing the tubes and allowing them to stand for 10 min, the supernatant was removed, and the mass m of the residue was measured. Each sample was measured in triplicate, and the average value was used to calculate the centrifugal sedimentation rate (WHC).

[0051] See results Figure 4 Under the conditions of a fixed temperature of 60℃ and a whey protein to walnut protein ratio of 5:3, the total ingredient content had a significant impact on the centrifugal sedimentation rate of the samples: the sedimentation rate was lowest when the total ingredient content was 1.38%; as the content increased to 2.75% and 4.12%, the sedimentation rate increased slightly; and when the content further increased to 5.50% and 6.88%, the sedimentation rate increased significantly. The reason for this phenomenon may be that at low total ingredient content, protein molecules are more dispersed in the system, with larger intermolecular distances, resulting in smaller and more stable aggregates, making them less prone to sedimentation during centrifugation; as the ingredient content increases, the protein molecule concentration rises, the frequency of intermolecular collisions and interactions (such as hydrophobic interactions and hydrogen bonds) increase, gradually forming larger aggregates; when the content exceeds a critical value (approximately 4.12%), the number and size of aggregates increase significantly, the system stability decreases, and ultimately, the centrifugal sedimentation rate increases dramatically.

[0052] Single-factor experiment to investigate the effect of whey protein to walnut protein ratio on centrifugal sedimentation rate: 10 mL solutions of whey protein to walnut protein at ratios of 4:0, 4:4, 4.5:3.5, 5:3, 5.5:2.5, 6:2, and 0:8 were taken from centrifuge tubes. The sample mass m0 was measured, and the solutions were centrifuged at 4000 r / min for 10 min. After centrifugation, the tubes were removed, allowed to stand for 10 min, the supernatant was removed, and the mass m of the residue was measured. Each sample was analyzed in triplicate, and the average value was used to calculate the centrifugal sedimentation rate (WHC). The total ingredient content was fixed at 4.12%, and the temperature was 60℃.

[0053] See results Figure 5 Under the conditions of a total ingredient content of 4.12% and a temperature of 60℃, the ratio of whey protein to walnut protein significantly modulates the centrifugal sedimentation rate of the samples: the sedimentation rate is lowest when the ratio is 8:0 (pure whey protein); the sedimentation rate increases when the ratio is adjusted to 6:2; the sedimentation rate increases again when the ratio is in the range of 5.5:3.5 to 4:4; and the sedimentation rate increases significantly when the ratio is 0:8 (pure walnut protein). The reason for this result may be that in the pure whey protein system, the degree of intermolecular aggregation is low and the particle stability is strong, resulting in a low sedimentation rate; as the proportion of walnut protein increases, the intermolecular interactions between the two proteins (such as exposure of hydrophobic groups and imbalance of electrostatic interactions) promote aggregate formation, and the sedimentation rate gradually increases; while in the pure walnut protein system, the aggregation behavior of the single protein is more significant, the aggregates formed are large and have poor stability, and are more likely to settle under centrifugation, ultimately showing the characteristic of increasing sedimentation rate with increasing walnut protein content.

[0054] Single-factor experiment to investigate the effect of magnetic stirring temperature on centrifugal sedimentation rate: 10 mL of solutions at magnetic stirring temperatures of 40℃, 50℃, and 60℃ were taken from centrifuge tubes, and the sample mass m0 was measured. The tubes were then centrifuged at 4000 r / min for 10 min. After centrifugation, the tubes were removed, allowed to stand for 10 min, the supernatant was removed, and the mass m of the residue was measured. Each sample was measured in triplicate, and the average value was used to calculate the centrifugal sedimentation rate (WHC).

[0055] See results Figure 6Under the condition that the ratio of whey protein to walnut protein was fixed at 6:2 and the total ingredient content was 4.12%, temperature had little effect on the centrifugal sedimentation rate of the samples, and there was no significant difference between groups. The reason for this phenomenon may be that in the range of 40-50℃, the thermal motion intensity of protein molecules increases only slightly, the degree of intermolecular aggregation does not change significantly, the system stability is good, and therefore the sedimentation rate does not fluctuate significantly. When the temperature rises to 60℃, the conformational unfolding of protein molecules increases, the exposure of hydrophobic groups increases, the intermolecular interaction is enhanced, and the size and number of aggregates increase slightly. Although there is no significant difference between groups, the sedimentation rate still shows a certain upward trend, reflecting the mild regulatory effect of temperature on the stability of the system.

[0056] The results of the single-factor experiments above show that the centrifugal sedimentation rate is better when the total ingredient content is 1.38%, 2.75%, and 4.12%, the whey protein to walnut protein ratio is 6:2, and the temperature is 40℃, 50℃, and 60℃. The average particle size is better when the total ingredient content is 4.12% and 5.50%, the whey protein to walnut protein ratio is 6:2, 4.5:2.5, and 4:4, and the temperature is 40℃.

[0057] Therefore, taking the intersection of these two factors, the optimal formulation and processing conditions were determined to be a temperature of 40℃, a total ingredient content of 4.12%, and a whey protein to walnut protein ratio of 6:2. Using these optimal conditions, the sample was prepared three times, and the particle size and centrifugal sedimentation rate were measured. The results are as follows. Figure 7 Under optimal conditions (temperature 40℃, total ingredient content 4.12%, whey protein to walnut protein ratio 6:2), the average particle size of the three repeatedly prepared samples remained stable at around 80μm, with no significant differences between groups. Combined with the previous verification results of centrifugation sedimentation rate, this further proves that these conditions can simultaneously ensure the particle size uniformity and stability of the system, verifying the reliability of the single-factor experimental intersection screening method, and providing stable process parameter support for the large-scale production of this formula.

[0058] See Figure 8 Under optimal conditions (temperature 40℃, total ingredient content 4.12%, whey protein to walnut protein ratio 6:2), the centrifugation sedimentation rates of the three repeatedly prepared samples remained stable in the range of 3% to 4%, with no significant differences between groups. Combined with the previous verification results of average particle size, this further confirms that these optimal conditions can simultaneously ensure the particle size uniformity and stability of the system, verifying the scientific validity of the single-factor experimental intersection screening method and providing reliable process parameter basis for the industrial production of this formula.

[0059] There were no significant differences in the average particle size and centrifugation sedimentation rate among the three replicate samples, and the data of the three groups were parallel. Therefore, the optimal ratio and treatment conditions for the wet mixing single-factor experiment were determined to be a temperature of 40℃, a total ingredient content of 4.12%, and a whey protein to walnut protein ratio of 6:2. Example 3

[0060] This embodiment provides a complete nutritional powder for the elderly, with the formulation shown in Table 1, which contains the component ratio of low-resistant dextrin. The preparation process is as follows: (1) Preparation of wet-mixed raw materials 4 g of walnut protein was dispersed in 360 mL of deionized water. The pH of the walnut protein dispersion was adjusted to 9.0 with 2 mol / L NaOH solution. The mixture was stirred at 20 °C for 1 h to ensure complete protein dissolution. 0.2 g of ellagic acid was then dissolved in 40 mL of deionized water, and the pH of the ellagic acid solution was adjusted to 9.0. The prepared protein solution (360 mL) and ellagic acid solution (40 mL) were then mixed and stirred at room temperature at pH 9.0 for 90 min. The pH of the mixture was adjusted to 7.0 to obtain the walnut protein-ellagic acid complex.

[0061] Weigh out 12g of whey protein and 6g of maltitol. Adjust the water bath temperature to 40℃. Measure 134mL of distilled water (the volume of the walnut protein-ellagic acid complex solution is approximately 400mL, totaling 534mL) into a beaker. Place the beaker containing water into the water bath. While magnetically stirring, add the whey protein, maltitol, and the walnut protein-ellagic acid complex solution (pH=7). Adjust the magnetic stirring speed to 20-25 rpm and magnetically stir the solution in the beaker at 40℃ for 30 minutes to obtain a wet-mixed raw material solution.

[0062] The wet-process raw material mixture was sheared at 12000 r / min for 3 min. The wet-process raw material mixture after high-speed shearing was freeze-dried, and the resulting powder was used for subsequent dry mixing.

[0063] (2) Dry mixing According to the formula of wheat resistant dextrin complete nutritional powder, weigh out the corresponding mass of solid corn syrup, wheat resistant dextrin, vegetable fat powder, maltodextrin, medium chain triglyceride powder, DHA powder, compound minerals and compound vitamins. Premix the above raw materials in a vortex mixer for 15 minutes, then add the material obtained by wet mixing, and continue mixing for 20 minutes to obtain the finished complete nutritional powder. Example 4

[0064] This embodiment provides a complete nutritional powder for the elderly, with the formulation shown in Table 1 for the proportions of resistant dextrin. Its preparation process is the same as in Example 3. Example 5

[0065] This embodiment provides a complete nutritional powder for the elderly, with the formulation shown in Table 1 for the proportions of highly resistant dextrin. Its preparation process is the same as in Example 3.

[0066] Table 1: Proportions Performance test

[0067] This includes testing of reconstitution characteristics, physicochemical properties, and digestibility.

[0068] Blending characteristics: (1) Dispersibility, see Figure 9 The addition of wheat resistant dextrin significantly affected the dispersion time, with the high-resistant dextrin group showing the shortest dispersion time, indicating its optimal dispersion performance. (2) Solubility, see Figure 10 The solubility of all four groups (control, low, medium, and high) remained at a high level, and there was no significant difference between the groups, indicating that the proportion of resistant dextrin added did not affect the final solubility of the nutritional powder. (3) Agglomeration rate, see Figure 11 The agglomeration rate decreased significantly with increasing resistant dextrin addition. The group with high wheat dextrin addition had the lowest agglomeration rate, indicating that resistant dextrin helps improve the moisture stability of the powder. (4) Wettability, see Figure 12 The wetting time of the medium and high resistant dextrin groups was significantly lower than that of the low resistant dextrin group, indicating that an appropriate amount and a high proportion of resistant dextrin can significantly shorten the wetting time of the powder.

[0069] Physicochemical properties: (1) Thermogravimetric analysis (TGA): Thermogravimetric analysis (TGA) was performed on the control, low, medium and high samples. The mass change curves of the four groups of samples with temperature highly overlapped, and the conclusion was that different proportions of resistant dextrin had no significant effect on the thermal stability of the nutritional powder. (2) Thermal stability DSC: See Figure 13 The heat flow trends of the four groups of samples were consistent, indicating that their heat conversion characteristics and the physical states of their components were similar.

[0070] Changes in thermal stability after adding resistant dextrin: The thermal stability curves of the control group without resistant dextrin (0-100℃) showed the largest variation, while those of the high-resistant dextrin-added group showed the smallest variation, demonstrating that the thermal stability of the complete nutritional powder with resistant dextrin was superior to that of the control group without resistant dextrin during this stage. At 190-200℃, the groups with resistant dextrin all showed significant endothermic peaks, while the control group without resistant dextrin did not, indicating that the control group had better thermal stability at this stage. In summary, adding resistant dextrin can improve the thermal stability of complete nutritional powder at 0-100℃ (complete nutritional powder should be prepared with 60℃ warm water, therefore adding resistant dextrin can improve its thermal stability when consumed), but it will reduce its thermal stability at the high temperature range of 190-200℃.

[0071] (3) Color difference, see the table below.

[0072] Table 2: Color Difference Comparison Results

[0073] Different letters indicate that there is a significant difference in each column (Tukey test). p <0.05) With the increase of resistant dextrin addition, the brightness (L*) decreased significantly and the total color difference (ΔE*) increased significantly, indicating that resistant dextrin will darken the color of the finished product.

[0074] (4) Particle size, see Figure 14 The average particle size was lowest in the resistant dextrin group. The particle size differences between the control group, the low-dextrin group, and the high-dextrin group were relatively small, and all were at a relatively high level.

[0075] Digestive characteristics: (1) Gastric phase protein digestibility, see Figure 15 Regardless of whether it is an elderly person or a normal person, the low-resistant dextrin group has the highest protein digestibility in the gastric phase. (2) Protein digestibility, see Figure 16 In both population groups, the final protein digestibility remained at a high level of 80%~90%, with relatively small differences between groups. (3) Rapidly digestible starch (RDS), see Figure 17 The RDS in the control group was significantly higher than that in other added groups, indicating that the addition of resistant dextrin can significantly reduce the rapid digestion rate of starch. (4) Slowly digested starch (SDS), see Figure 18 As the amount of resistant dextrin added increases, the proportion of SDS shows a significant decreasing trend. (5) Resistant starch (RS), see Figure 19 The RS content was directly proportional to the amount of resistant dextrin added. The high-concentration group showed significantly higher RS ​​content in both elderly and normal individuals during simulated digestion, demonstrating its excellent anti-digestion properties.

[0076] Based on the above research, it was determined that the high-resistant dextrin group had the best technical performance.

[0077] Although the present invention has been described above through embodiments, those skilled in the art should understand that any improvements and modifications made to the present invention without departing from its spirit and essence should fall within the protection scope of the present invention.

Claims

1. A complete nutritional powder for the elderly containing wheat resistant dextrin, characterized in that, The following ingredients are included in parts by weight: The ingredients are: 25-45 parts solid corn syrup, 5-30 parts starch-based resistant dextrin, 10-20 parts protein, 10-12 parts vegetable fat powder, 8-12 parts maltodextrin, 0-0.3 parts ellagic acid, 5-8 parts maltitol, 1-2 parts medium-chain triglycerides, 0.1-0.5 parts DHA powder, 1-5 parts complex minerals, and 1-3 parts complex vitamins.

2. The complete nutritional powder for the elderly containing wheat resistant dextrin according to claim 1, characterized in that, The starch-based resistant dextrin is wheat starch resistant dextrin, and the dosage is 15-25 parts.

3. The complete nutritional powder for the elderly containing wheat resistant dextrin according to claim 1, characterized in that, The protein is composed of 10-15 parts whey protein and 3-5 parts walnut protein; the ellagic acid is 0.1-0.3 parts.

4. The complete nutritional powder for the elderly containing wheat resistant dextrin according to claim 1, characterized in that, The following ingredients are included in parts by weight: The ingredients are: 25 parts solid corn syrup, 25 parts wheat resistant dextrin, 12 parts whey protein, 12 parts vegetable fat powder, 10 parts maltodextrin, 4 parts walnut protein, 0.1-0.3 parts ellagic acid, 6 parts maltitol, 1.2 parts medium-chain triglycerides, 0.3 parts DHA powder, 3 parts compound minerals, and 2 parts compound vitamins.

5. The method for preparing the complete nutritional powder for the elderly according to any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Preparation of wet mixed raw materials: Disperse walnut protein in water and adjust the pH of the walnut protein dispersion to 8-10; prepare an ellagic acid solution with a mass concentration of 0.2-1% and mix the walnut protein solution and the ellagic acid solution to obtain a walnut protein-ellagic acid complex; Whey protein and maltitol were mixed with the walnut protein-ellagic acid complex to prepare a wet-mixed raw material solution, which was then freeze-dried into a powder. (2) Dry mixing: Weigh the corresponding mass of solid corn syrup, wheat resistant dextrin, vegetable fat powder, maltodextrin, medium chain triglyceride powder, DHA powder, compound minerals and compound vitamins according to the formula of wheat resistant dextrin whole nutrition powder. Premix the above raw materials in a vortex mixer for 15 min, then add the powder obtained by wet mixing, and continue mixing for 20 min to obtain the finished whole nutrition powder.

6. The preparation method according to claim 5, characterized in that, In step (1), walnut protein is dispersed in water, the pH of the walnut protein dispersion is adjusted to 9.0, and stirred for 0.5 to 2 hours. The pH of the ellagic acid solution is adjusted to 9.0, and the walnut protein solution and ellagic acid solution are mixed. The pH is maintained at 9.0 and stirred at room temperature for 1 to 2 hours.

7. The preparation method according to claim 6, characterized in that, The walnut protein solution and ellagic acid solution were mixed and stirred at room temperature for 90 min while maintaining the pH at 9.

0. The pH of the mixture was then adjusted to 7.0 to obtain the walnut protein-ellagic acid complex.

8. The preparation method according to claim 5, characterized in that, In step (1), whey protein and maltitol are prepared into a solution with a total mass concentration of 10-15% under water bath conditions of 35-45℃.

9. The preparation method according to any one of claims 5 to 8, characterized in that, In step (1), the total content of wet-mixed raw materials and the ratio of water are 4-6%.

10. The preparation method according to any one of claims 5 to 8, characterized in that, In step (2), the remaining raw materials are premixed in a vortex mixer for 15 minutes, and then the material obtained by wet mixing is added and mixed for another 20 minutes to obtain the finished product of complete nutritional powder.

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