Preparation method of brown maltodextrin

Abstract

The invention belongs to the technical field of maltodextrin, and particularly discloses a preparation method of brown maltodextrin. The preparation method of the brown maltodextrin comprises the following steps: (1) drying and sieving corn starch, and dispersing the corn starch in deionized water to obtain starch paste; (2) adding citric acid into the starch paste, adjusting the pH value, adding alpha-amylase, stirring, and carrying out enzyme deactivation treatment to obtain a mixed solution; (3) performing puffing treatment on the mixed solution under the treatment conditions that the temperatures of a twin-screw extruder are 45-55 DEG C, 55-65 DEG C, 65-85 DEG C and 85-115 DEG C respectively, and performing extrusion to obtain maltodextrin; and (4) dispersing maltodextrin in deionized water to obtain maltodextrin milk, and mixing, homogenizing and spray-drying the maltodextrin milk and the caramel syrup to obtain the maltodextrin. Various raw materials and steps are matched, the obtained maltodextrin has relatively low moisture absorption rate, and the risk that the soft sweets become sticky due to moisture absorption is reduced, so that the taste is influenced.

Description

Technical Field

[0001] This application relates to the technical field of maltodextrin, and in particular to a method for preparing brown maltodextrin. Background Technology

[0002] Maltodextrin is a low-degree deionized hydrolysate obtained by partial deionization of starch. It is a polysaccharide mixture composed of glucose units and is usually a white, tasteless or slightly sweet powder. It is highly soluble in deionized water and is widely used in many industries such as food, medicine, and chemicals.

[0003] Brown maltodextrin, also known as caramelized maltodextrin, is made from starch. The starch is prepared by adding deionized water to form a starch slurry, then adding amylase for deionization hydrolysis, decolorization and filtration, evaporation and concentration, adding caramel color, homogenization, spray drying, and packaging to obtain brown maltodextrin. Brown maltodextrin is used in baked goods, compound seasonings, beverages, and confectionery, providing a natural, warm brown color and imparting a caramel and malty flavor to the products.

[0004] The brown maltodextrin prepared in the prior art has a DE value of 15-20, exhibiting good deionized water solubility and flowability. However, it is prone to absorbing moisture and clumping in high humidity environments, demonstrating strong hygroscopicity. In the preparation of gummies, to maintain their moisture retention, a low to medium DE value (e.g., 5-15) is typically used. This allows the gummies to slowly and evenly absorb small amounts of deionized moisture during storage, keeping them soft inside, while preventing the surface from becoming sticky due to excessive or rapid moisture absorption, which would affect their appearance and taste. Summary of the Invention

[0005] To address the problem of excessively high DE values ​​in maltodextrin leading to excessively high hygroscopicity in the prepared gummies, this application provides a method for preparing brown maltodextrin.

[0006] This application provides a method for preparing brown maltodextrin, using the following technical solution: A method for preparing brown maltodextrin includes the following steps: (1) Dry and sieve the corn starch, disperse it in deionized water, and stir it evenly to obtain a starch paste; (2) Add citric acid to the starch paste, adjust the pH to 5.9-6.1, add α-amylase, stir at 60-62℃ for 50-55 min, and inactivate the enzyme at 88-90℃ for 12-15 min to obtain a mixture; (3) The mixture from step (2) is subjected to expansion treatment. The treatment conditions are: the temperatures of the first, second, third and fourth sections of the twin-screw extruder are 45-55℃, 55-65℃, 65-85℃ and 85-115℃ respectively, and the temperature of the fifth section of the extruder is 150-160℃. The mixture is extruded and dried to obtain maltodextrin. (4) Disperse maltodextrin in deionized water to obtain maltodextrin milk, mix maltodextrin milk and caramel syrup, homogenize, and spray dry at low temperature to obtain maltodextrin.

[0007] By employing the above technical solution, corn starch is dried to remove excess deionized water, ensuring stable concentration during subsequent dispersion. The starch paste is then enzymatically hydrolyzed, breaking down the long-chain deionized corn starch into shorter-chain dextrins and oligosaccharides. The mixture is then puffed using a twin-screw extrusion process. The material undergoes a gradual temperature change from low to high under screw conveying, achieving gradual evaporation of moisture and thorough gelatinization. Finally, instantaneous puffing is achieved at a high temperature of 150-160℃. Under the combined action of high temperature, high pressure, and high shear force, the dextrin molecular structure undergoes physical changes (such as chain breakage and orientation rearrangement), altering the product's solubility, viscosity, water absorption, and particle structure. When the material is extruded from the die, the pressure drops sharply, causing the water to vaporize instantaneously, forming a porous structure, resulting in maltodextrin.

[0008] The solid maltodextrin obtained by extrusion is redissolved and prepared into an emulsion. The maltodextrin emulsion and caramel syrup are then mixed. The main purpose of the caramel syrup is to color the final product, giving it a brown color. Homogenization makes the maltodextrin and syrup mix more evenly, forming a fine colloidal dispersion. Spray drying results in maltodextrin with low hygroscopicity, reducing the risk of the gummies becoming sticky due to moisture absorption.

[0009] Preferably, the corn starch is pretreated, including the following steps: (1) Disperse corn starch in deionized water, adjust the pH to 9-10 with sodium hydroxide solution, add sodium trimetaphosphate and Tween 80, react at 60-65℃ for 4-5 hours, adjust the pH with hydrochloric acid solution to obtain cross-linked starch solution, spray dry to obtain granules; (2) Disperse the yeast extract product into deionized water, add the granules and dietary fiber from step (1), sonicate for 2-3 hours, and dry to obtain pretreated corn starch.

[0010] By employing the above technical solution, the alkaline environment activates the hydroxyl groups on the surface of corn starch granules through ionization, enhancing their reactivity with sodium trimetaphosphate and cross-linking into a three-dimensional network structure. This process simultaneously prevents starch agglomeration, improves the starch's heat resistance and paste stability, reduces the viscosity and heat sensitivity after gelatinization, and promotes uniform starch dispersion at Tween 80. Furthermore, it increases the solubility of sodium trimetaphosphate in the starch suspension, enhancing its contact efficiency with the starch hydroxyl groups and ensuring uniform cross-linking. Acidic conditions terminate the cross-linking reaction and neutralize the system. Spray drying rapidly removes deionized water, yielding free-flowing granular cross-linked starch.

[0011] Yeast extract, dispersed in deionized water, is rich in amino acids, peptides, vitamins, and minerals. While it enhances enzymatic hydrolysis efficiency, the three-dimensional network structure of cross-linked starch is more difficult to disrupt, limiting enzyme action to a small amount of short-chain starch on the particle surface, resulting in incomplete hydrolysis. Adding particles and dietary fiber allows the yeast extract to adhere to the microporous surface of the particles, improving their stability. The adhesive properties of dietary fiber further enhance this stability, preventing starch molecule aggregation through steric hindrance, reducing sedimentation, hydrolysis efficiency, and hygroscopicity. This facilitates subsequent puffing, protecting flavor compounds from high temperatures and oxidation, and achieving sustained flavor release and long-term stability. Cross-linked starch hinders the contact between α-amylase and starch chains, reducing hydrolysis efficiency and lowering the DE value of the final product. Furthermore, the peptides in the yeast extract bind to the hydroxyl groups of dextrin, masking some hydrophilic groups and reducing the hygroscopicity of the final product.

[0012] Preferably, the mass ratio of the corn starch, yeast extract, and dietary fiber is 1:0.5-0.6:0.2-0.3.

[0013] By adopting the above technical solution, the mass ratio of corn starch, yeast extract, and dietary fiber is further limited within a certain range. The resulting corn starch has good stability. The yeast extract is loaded on the microporous surface of the particles, improving the stability of the particles. The dietary fiber allows the yeast extract to adhere to the particle surface, increasing the structural stability of the particles. In subsequent enzymatic hydrolysis and puffing processes, it hinders the contact between α-amylase and starch chains, reduces hydrolysis efficiency, protects the starch from damage caused by high temperature and oxidation, and ensures the stability of the starch flavor.

[0014] Preferably, the preparation method of the yeast extract product includes the following steps: dissolving the yeast extract in deionized water, adjusting the pH to 5.0-6.0, adding chitosan and stirring for 20-25 minutes, adding tea polyphenols and peptone under a nitrogen atmosphere, stirring at 55-60℃ for 1-2 hours, and freeze-drying to obtain the yeast extract product.

[0015] By employing the above technical solution, yeast extract itself contains abundant deionized water-soluble components such as amino acids, peptides, nucleotides, vitamins, and minerals. Adjusting the pH to 5.0-6.0 with acid effectively dissolves chitosan, a positively charged natural polysaccharide. Chitosan combines with the negatively charged components in yeast extract through electrostatic interactions, forming a stable complex system and enhancing the deionized water retention, emulsifying properties, and biocompatibility of the yeast extract. Under a nitrogen atmosphere, oxidation of tea polyphenols and yeast extract is prevented. Tea polyphenols enhance the antioxidant capacity of yeast extract, protecting it and other components from oxidative damage. The polyphenolic hydroxyl structure of tea polyphenols can covalently or non-covalently bind to the amino groups of chitosan and proteins, participating in and strengthening the formation of the complex network, making the structure more stable. In subsequent starch enzymatic hydrolysis, it hinders the contact between α-amylase and starch chains, reducing hydrolysis efficiency. Peptone further enriches the amino acid profile and peptide content of the product, increasing its umami and richness, and increasing the colloidal complexity of the system, which helps stabilize the formed complex.

[0016] Freeze-drying yields a loose, porous, and highly soluble powder that retains the antioxidant activity of tea polyphenols, vitamins / enzymes / flavor substances from yeast extract and peptone, as well as the structure of the complex. This facilitates subsequent processing, reduces the DE value of the final maltodextrin, improves its stability, reduces its hygroscopicity, enhances the stability of the puffed structure, and prevents collapse or shrinkage.

[0017] Preferably, the mass ratio of the yeast extract, chitosan, and tea polyphenols is 1:0.6-0.7:0.3-0.4.

[0018] By employing the above technical solution, the mass ratio of yeast extract, chitosan, and tea polyphenols is further limited within a certain range. Synergistic effects exist among the various components. Chitosan, a positively charged natural polysaccharide, possesses excellent film-forming properties, adsorption capacity, and biocompatibility. Through electrostatic interactions, it binds with other negatively charged components (such as tea polyphenols and carboxyl groups in peptone) to form a stable composite structure, reducing losses during subsequent processing or storage. The antioxidant capacity of tea polyphenols effectively scavenge free radicals, protecting the yeast flavor components and the tea itself from oxidative deterioration. The polyphenolic structure of tea polyphenols allows it to bind not only to chitosan but also to protein fragments in the yeast extract. This strengthens and densifies the complex network formed by chitosan and yeast extract, improving its stability.

[0019] The combination of multiple components improves the stability of the system and effectively prevents particle aggregation during subsequent processing. The puffing process forms a more uniform and delicate porous puffing structure, avoiding clumping and oxidation caused by component separation during drying. It also assists in the pretreatment of starch substrate, reduces enzymatic hydrolysis efficiency, and improves stability.

[0020] Preferably, the method for preparing the dietary fiber includes the following steps: washing and drying peanut shells, sieving them, then dispersing them in a sodium hydroxide solution for alkaline hydrolysis, washing them with deionized water, dispersing them again in deionized water, adding cellulase and pectinase for enzymatic hydrolysis, obtaining a filtrate, centrifuging the filtrate, taking the centrifuged liquid and filtering and concentrating it using a nanofiltration device with a relative molecular weight cutoff of 1500-2000 Dalton, collecting the concentrate, adding tara gum, xylitol, and calcium chloride, and freeze-drying to obtain dietary fiber.

[0021] By employing the above technical solution, sodium hydroxide solution is used to disrupt the dense structure of peanut shells, dissolving some deionized water-insoluble hemicellulose and impurities such as fats and pigments. Cellulase breaks down cellulose into small molecules such as cellulosic sugars, cellobioses, and even glucose. Pectinase breaks down pectin substances in the intercellular matrix, further disintegrating the plant structure and releasing soluble components.

[0022] After filtration and centrifugation, insoluble solid residues remaining after enzymatic hydrolysis are removed, yielding a centrifuged liquid containing soluble dietary fiber. The liquid is then concentrated by filtration, retaining target products with molecular weights greater than 2000 Daltons (such as oligosaccharides and some soluble polysaccharides), while allowing smaller molecular weight impurities (such as salts, monosaccharides, and trace amounts of pigments or bitter substances) to be discharged with the filtrate. Tara gum, xylitol, and calcium chloride are added to the concentrate. Tara gum improves the solubility, taste, and texture of the final product, enhances the water-holding capacity and viscosity of dietary fiber, prevents powder clumping, and produces a synergistic thickening effect with dietary fiber. Tara gum, a high-viscosity hydrophilic colloid, hinders the diffusion and movement of α-amylase, reducing the efficiency of enzyme-starch molecule collisions, thus slightly inhibiting the enzymatic hydrolysis reaction and improving product stability. While tara gum itself contains a large number of hydroxyl groups, the cross-linking effect of calcium chloride causes the polysaccharide chains of tara gum to become tightly intertwined, partially masking the hydroxyl groups and reducing the overall moisture absorption rate of the final product.

[0023] Xylitol modifies the product's flavor and synergistically enhances physiological activity with dietary fiber. Calcium chloride binds to the carboxyl groups on tara gum molecules, forming a stable gel structure that encapsulates enzymes within the gel network. This creates steric hindrance, slightly hindering enzymatic hydrolysis, and more effectively locking in moisture and fixing starch molecules, resulting in a stronger and more lasting inhibitory effect on sedimentation and reducing the product's hygroscopicity. The resulting dietary fiber is porous and spongy, with good solubility and viscosity, which helps in the subsequent combination of yeast extract and other components, inhibiting enzyme activity and enhancing the stability and storage resistance of the puffing process.

[0024] Preferably, the mass ratio of the concentrate, tara gum, and calcium chloride is 1:0.5-0.6:0.3-0.4.

[0025] By employing the above technical solutions, tara gum can increase the viscosity of the concentrate. Its long-chain molecules can bond with fiber molecules in the concentrate through hydrogen bonds to form a continuous fiber-gel network, significantly improving the system's deionized water retention, oil retention, and viscosity. During freeze-drying, it can form a stable network structure, which helps to form a porous, loose, and non-collapsed perfect solid framework. Calcium chloride and tara gum work synergistically; their molecular chains can undergo ionic cross-linking in the presence of calcium ions, forming a stronger and more stable three-dimensional gel network, resulting in a more solid powder that is less prone to breakage. The dietary fiber obtained by combining multiple components is easily soluble in deionized water, does not separate into layers, and has good thermal stability. This facilitates the subsequent loading and adsorption of yeast extract and other components, inhibits enzyme activity, and enhances the stability and storage resistance of the puffing process.

[0026] Secondly, this application also provides brown maltodextrin prepared by the above-mentioned method.

[0027] In summary, this application has the following beneficial effects: 1. In this application, an extrusion process is performed to help the starch deionized hydrolysis products form a uniform porous structure, thereby enhancing the stability of the system and preventing clumping.

[0028] 2. In the twin-screw extrusion puffing process of this application, the material undergoes a process from low temperature to high temperature under the screw conveyor, so as to achieve gradual evaporation of moisture, full gelatinization, and finally instantaneous puffing in the high temperature zone of 150-160℃.

[0029] 3. In this application, maltodextrin milk and caramel syrup are mixed. The main purpose of the caramel syrup is to color the final product to make it brown. Homogenization makes the maltodextrin and syrup mix more evenly, forming a fine colloidal dispersion system. Spray drying is then performed to obtain maltodextrin. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the embodiments.

[0031] The raw materials used in the examples and comparative examples are all commercially available.

[0032] Example of corn starch preparation Preparation Example 1 Pretreatment of corn starch includes the following steps: (1) Disperse 1 kg of corn starch into 10 L of deionized water, adjust the pH to 10 with 10% sodium hydroxide solution, add 0.25 kg of sodium trimetaphosphate and 0.1 kg of Tween 80, react at 62 °C for 4.5 h, adjust the pH to 5.0 with 2% hydrochloric acid solution to obtain cross-linked starch solution, spray dry (inlet air temperature 90 °C, outlet air temperature 65 °C) to obtain granules; (2) Disperse the yeast extract product into 15L of deionized water, add the granules and dietary fiber from step (1), sonicate for 2.5h, and dry to obtain pretreated corn starch.

[0033] The mass ratio of corn starch, yeast extract, and dietary fiber is 1:0.5:0.3.

[0034] The preparation method of the yeast extract product includes the following steps: 2 kg of yeast extract is dissolved in 10 L of deionized water, the pH is adjusted to 6.0, chitosan is added and stirred for 22 min, tea polyphenols and 0.3 kg of peptone are added under a nitrogen atmosphere, the mixture is stirred at 58 °C for 1.5 h, and then freeze-dried to obtain the yeast extract product; the yeast extract was purchased from Hebei Rencan Biotechnology Co., Ltd.

[0035] The mass ratio of yeast extract, chitosan, and tea polyphenols was 1:0.6:0.4.

[0036] The preparation method of dietary fiber includes the following steps: 5 kg of peanut shells are washed, dried, and passed through a 30-mesh sieve. The shells are then dispersed in 10 L of a 3% sodium hydroxide solution for alkaline hydrolysis. After washing with deionized water, the shells are dispersed again in 10 L of deionized water. Cellulase (0.08% of the peanut shell weight) and pectinase (0.07% of the peanut shell weight) are added for enzymatic hydrolysis (40℃, 250 min, pH adjusted to 4.3, enzyme inactivation at 90℃ for 10 min). The resulting filtrate is centrifuged, and the centrifuged liquid is concentrated by filtration using a nanofiltration device with a molecular weight cutoff of 1500 Daltons. The pressure is adjusted to 2.5 MPa, and the concentrate is collected. Tara gum, 0.8 kg of xylitol, and calcium chloride are added, and the solution is freeze-dried to obtain dietary fiber. The pectinase was purchased from Hubei Haijia Biotechnology Co., Ltd., and the cellulase was purchased from Zhejiang Yicun Biotechnology Co., Ltd.

[0037] The mass ratio of the concentrate, tarara, and calcium chloride is 1:0.5:0.3.

[0038] Preparation Example 2 The difference from Preparation Example 1 is that yeast extract is not added to the finished product.

[0039] Preparation Example 3 The difference from Preparation Example 1 is that no dietary fiber is added.

[0040] Preparation Example 4 The difference from Preparation Example 1 is that the mass ratio of corn starch, yeast extract, and dietary fiber is 1:0.6:0.2.

[0041] The mass ratio of yeast extract, chitosan, and tea polyphenols was 1:0.7:0.3.

[0042] The mass ratio of the concentrate, tarara, and calcium chloride is 1:0.6:0.4.

[0043] Preparation Example 5 The difference from Preparation Example 1 is that the mass ratio of corn starch, yeast extract, and dietary fiber is 1:0.2:0.7.

[0044] Preparation Example 6 The difference from Preparation Example 1 is that chitosan is not added in the preparation method of the yeast extract product.

[0045] Preparation Example 7 The difference from Preparation Example 1 is that tea polyphenols are not added in the preparation method of the yeast extract product.

[0046] Preparation Example 8 The difference from Preparation Example 1 is that the mass ratio of yeast extract, chitosan and tea polyphenols is 1:0.1:0.6.

[0047] Preparation Example 9 The difference from Preparation Example 1 is that tara gum is not added in the preparation method of dietary fiber.

[0048] Preparation Example 10 The difference from Preparation Example 1 is that calcium chloride is not added in the preparation method of dietary fiber.

[0049] Preparation Example 11 The difference from Preparation Example 1 is that the mass ratio of the concentrate, tara gum, and calcium chloride is 1:0.08:0.5. Example

[0050] Example 1 A method for preparing brown maltodextrin includes the following steps: (1) Dry 1 kg of corn starch, pass it through a 70-mesh sieve, disperse it in 3.5 L of deionized water, stir well to obtain starch paste; (2) Add citric acid to the starch paste, adjust the pH to 6.1, add α-amylase (the amount of α-amylase added is 0.06% of the weight of corn starch), stir at 60℃ for 50 min, and inactivate the enzyme at 90℃ for 15 min to obtain a mixture. (3) The mixture from step (2) is subjected to expansion treatment by extrusion expansion treatment using a twin-screw extruder. The treatment conditions are as follows: the temperatures of the first, second, third, and fourth sections of the twin-screw extruder are 45℃, 55℃, 65℃, and 85℃, respectively; the temperature of the fifth section of the extruder is 150℃; the die pressure is 1.2MPa; the screw speed is 500r / min; the extruder is then dried to obtain maltodextrin. The length-to-diameter ratio of the twin-screw extruder is 20:1; the length of the screw is 90.0cm; the feeding speed of the twin-screw extruder is 18kg / h; and the length of the fifth section of the extruder is 20cm.

[0051] (4) Disperse maltodextrin in 3L of deionized water to obtain maltodextrin milk. Mix maltodextrin milk and caramel syrup at a mass ratio of 500:2. Homogenize at 18°C ​​and 7.5MPa. Spray dry at low temperature. After spray drying, obtain maltodextrin (spray drying inlet air temperature 90°C, outlet air temperature 65°C).

[0052] α-Amylase was purchased from Zhejiang Yicun Biotechnology Co., Ltd.

[0053] Example 2 A method for preparing brown maltodextrin differs from Example 1 in that it includes the following steps: (1) Dry 1.1 kg of corn starch, pass it through a 70-mesh sieve, disperse it in 3 L of deionized water, stir it evenly, and obtain starch paste; (2) Add citric acid to the starch paste, adjust the pH to 6.0, add α-amylase (the amount of α-amylase added is 0.05% of the weight of corn starch), stir at 62℃ for 55 min, and inactivate the enzyme at 88℃ for 15 min to obtain a mixture. (3) The mixture from step (2) is subjected to puffing treatment. The treatment conditions are as follows: the temperatures of the first, second, third, and fourth sections of the twin-screw extruder are 55°C, 65°C, 85°C, and 115°C, respectively; the temperature of the fifth section of the extruder is 160°C; the die pressure is 1.5 MPa; the screw speed is 500 r / min; the mixture is extruded and dried to obtain maltodextrin. (4) Disperse maltodextrin in 2.5L of deionized water to obtain maltodextrin milk. Mix maltodextrin milk and caramel syrup at a mass ratio of 500:2, homogenize at 17℃ and 8MPa, and spray dry at low temperature to obtain maltodextrin (spray drying inlet air temperature 90℃ and outlet air temperature 65℃).

[0054] Example 3 A method for preparing brown maltodextrin differs from Example 1 in that the corn starch is pretreated (the corn starch is pretreated before drying and sieving), and the pretreatment method is the same as in Preparation Example 1.

[0055] Example 4 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 2.

[0056] Example 5 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 3.

[0057] Example 6 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 4.

[0058] Example 7 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 5.

[0059] Example 8 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 6.

[0060] Example 9 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 7.

[0061] Example 10 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 8.

[0062] Example 11 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 9.

[0063] Example 12 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 10.

[0064] Example 13 A method for preparing brown maltodextrin differs from Example 3 in that the corn starch pretreatment is performed according to Preparation Example 11.

[0065] Comparative Example Comparative Example 1 A method for preparing brown maltodextrin differs from Example 1 in that it does not involve puffing.

[0066] Performance testing The preparation methods of the brown maltodextrin obtained in Examples 1-13 and Comparative Example 1 were subjected to performance tests. DE values ​​were tested according to the national standard GB / T 20884-2021; Stability test (settling property): Weigh 10g of dry sample, add distilled deionized water to dissolve it, heat in a deionized water bath at 60℃ for 1min to fully dissolve it, cool to room temperature, transfer to a 100mL stoppered graduated cylinder and make up to volume, let stand for one week, observe its sedimentation property, and read the volume of the lower layer sedimentation.

[0067] Hygroscopicity test: Dry the sample, weigh the initial weight m0, and then place it in an environment with a relative humidity of 75% and a temperature of 25℃ for 3 days. Weigh the final sample weight m. t Calculate the moisture absorption rate; Moisture absorption rate = (m t -m0) / m0×100%. The test results are shown in Table 1.

[0068] Table 1 Test data for the examples and comparative examples DE value % sedimentation mL Moisture absorption rate % Example 1 12.4 95.0 10.8 Example 2 12.2 95.3 10.6 Example 3 6.5 99.9 6.2 Example 4 10.5 96.2 9.6 Example 5 9.1 97.3 8.7 Example 6 6.6 99.8 6.3 Example 7 8.5 98.1 7.9 Example 8 9.3 97.0 8.9 Example 9 8.8 97.7 8.4 Example 10 8.0 98.7 7.2 Example 11 8.9 97.5 8.5 Example 12 8.6 98.0 8.0 Example 13 7.8 99.0 7.0 Comparative Example 1 17.5 89.1 15.6 As can be seen from Table 1, the preparation methods of brown maltodextrin prepared in Examples 1-2 of this application have good comprehensive performance. Among them, Example 1 has a DE value of 12.4%, a settling efficiency of 95.0 mL, and a moisture absorption rate of 10.8%. It is evident that the puffing process of the brown maltodextrin prepared in this application helps the starch deionized hydrolysis products form a uniform porous structure, enhances the stability of the system, and forms a dextrin mixture with a certain puffed structure. This results in good flowability and low moisture absorption, reducing the risk of the gummies becoming sticky due to moisture absorption.

[0069] Example 3 involved pretreating corn starch. As shown in Table 1, Example 3 exhibited a DE value of 6.5%, a sedimentation rate of 99.9 mL, and a moisture absorption rate of 6.2%. This indicates that the pretreated corn starch possesses a better three-dimensional network structure. The cross-linked starch hinders the contact between α-amylase and starch chains, reducing hydrolysis efficiency and subsequently lowering the DE value of the final product, thus improving stability. Furthermore, the peptides from the yeast extract bind to the hydroxyl groups of dextrin, partially masking the hydrophilic groups and reducing the moisture absorption rate of the final product.

[0070] Examples 4-5 involved pretreatment of corn starch without the addition of yeast extract or dietary fiber. Table 1 shows that the DE value, sedimentation properties, and moisture absorption of Examples 4-5 were significantly worse than Example 3, but better than Examples 1-2. This indicates that the yeast extract and dietary fiber played different roles. The yeast extract, loaded on the microporous surface of the particles, improved particle stability, while the dietary fiber allowed the yeast extract to adhere to the particle surface, increasing structural stability. Without the yeast extract, α-amylase lost its activator support, resulting in decreased activity. The three-dimensional network structure of cross-linked starch was more difficult to disrupt, and the enzyme could only act on a small amount of short-chain starch on the particle surface, leading to an overall decrease in the DE value. Furthermore, dextrin molecules lost their steric hindrance, making them prone to rapid aggregation and crystallization upon cooling. The hydroxyl groups of dextrin molecules were largely exposed, increasing their binding capacity with water molecules, making them more susceptible to moisture absorption and clumping in humid environments, thus reducing storage stability. Dietary fiber, through steric hindrance, hindered starch molecule aggregation, reducing sedimentation properties, hydrolysis efficiency, and moisture absorption.

[0071] Example 7 changed the mass ratio of corn starch, yeast extract, and dietary fiber. As shown in Table 1, the DE value, sedimentation, and moisture absorption of Example 7 were significantly worse than those of Example 3, but better than those of Examples 4-5. This indicates that there is a synergistic effect between the yeast extract and dietary fiber in the subsequent enzymatic hydrolysis and puffing treatment of starch, which hinders the contact between α-amylase and starch chains, reduces hydrolysis efficiency, protects starch from damage caused by high temperature and oxidation, and ensures the stability of starch flavor.

[0072] Examples 8-9 involved the preparation of the yeast extract product without the addition of chitosan or tea polyphenols. Example 10 altered the mass ratio of yeast extract, chitosan, and tea polyphenols. Table 1 shows that the DE value, sedimentation properties, and hygroscopicity of Examples 8-9 were significantly better than Example 4, but worse than Example 3. Similarly, the corresponding test results of Example 10 were significantly better than Examples 8-9, but worse than Example 3. This indicates that chitosan and the negatively charged components in the yeast extract bind through electrostatic interactions, forming a stable composite system. The polyphenolic structure of tea polyphenols allows it to bind not only to chitosan but also to protein fragments in the yeast extract, reinforcing and densifying the complex network formed by chitosan and yeast extract, thus improving its stability. In subsequent enzymatic hydrolysis of starch, this reduced the DE value of the final maltodextrin, improved its stability, decreased its hygroscopicity, enhanced the stability of the puffed structure, and prevented collapse or shrinkage.

[0073] Examples 11-12 involved the preparation of dietary fiber without the addition of tara gum or calcium chloride. Example 10 varied the mass ratio of the concentrate, tara gum, and calcium chloride. Table 1 shows that the DE value, sedimentation properties, and moisture absorption of Examples 11-12 were significantly better than those of Example 5, but worse than those of Example 3. Similarly, the corresponding test results of Example 13 were significantly better than those of Examples 11-12, but worse than those of Example 3. This indicates that calcium chloride and tara gum work synergistically; their molecular chains can undergo ionic cross-linking in the presence of calcium ions, forming a stronger and more stable three-dimensional gel network. This reduces the efficiency of enzyme-starch molecule collisions, thus slightly inhibiting enzymatic hydrolysis, improving product stability, and reducing the overall moisture absorption of the final product.

[0074] Comparative Example 1, which did not undergo puffing treatment, showed, as can be seen from Table 1, an increased DE value, a decreased sedimentation value, and an increased hygroscopicity. This indicates that the puffed material in this application exhibits good flowability and low hygroscopicity, reducing the risk of the gummies becoming sticky due to moisture absorption.

[0075] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing brown maltodextrin, characterized in that, Includes the following steps: (1) Dry and sieve the corn starch, disperse it in deionized water, and stir evenly to obtain starch paste; (2) Add citric acid to the starch paste, adjust the pH to 5.9-6.1, add α-amylase, stir at 60-62℃ for 50-55 min, and inactivate the enzyme at 88-90℃ for 12-15 min to obtain a mixture; (3) The mixture from step (2) is subjected to expansion treatment. The treatment conditions are as follows: the temperatures of the first, second, third and fourth sections of the twin-screw extruder are 45-55℃, 55-65℃, 65-85℃ and 85-115℃ respectively, and the temperature of the fifth section of the extruder is 150-160℃. The mixture is then extruded and dried to obtain maltodextrin. (4) Disperse maltodextrin in deionized water to obtain maltodextrin milk, mix maltodextrin milk and caramel syrup, homogenize, and spray dry at low temperature to obtain maltodextrin.

2. The method for preparing brown maltodextrin according to claim 1, characterized in that, Pretreatment of corn starch includes the following steps: (1) Disperse corn starch in deionized water, adjust the pH to 9-10 with sodium hydroxide solution, add sodium trimetaphosphate and Tween 80, react at 60-65℃ for 4-5 hours, adjust the pH with hydrochloric acid solution to obtain cross-linked starch solution, spray dry to obtain granules; (2) Disperse the yeast extract product into deionized water, add the granules and dietary fiber from step (1), sonicate for 2-3 hours, and dry to obtain pretreated corn starch.

3. The method for preparing brown maltodextrin according to claim 2, characterized in that, The mass ratio of the corn starch, yeast extract, and dietary fiber is 1:0.5-0.6:0.2-0.

3.

4. The method for preparing brown maltodextrin according to claim 2, characterized in that, The preparation method of the yeast extract product includes the following steps: dissolving the yeast extract in deionized water, adjusting the pH to 5.0-6.0, adding chitosan and stirring for 20-25 minutes, adding tea polyphenols and peptone under a nitrogen atmosphere, stirring at 55-60℃ for 1-2 hours, and freeze-drying to obtain the yeast extract product.

5. The method for preparing brown maltodextrin according to claim 4, characterized in that, The mass ratio of the yeast extract, chitosan, and tea polyphenols is 1:0.6-0.7:0.3-0.

4.

6. The method for preparing brown maltodextrin according to claim 2, characterized in that, The method for preparing the dietary fiber includes the following steps: washing and drying peanut shells, sieving them, then dispersing them in sodium hydroxide solution for alkaline hydrolysis, washing them with deionized water, dispersing them again in deionized water, adding cellulase and pectinase for enzymatic hydrolysis, obtaining a filtrate, centrifuging the filtrate, taking the centrifuged liquid and filtering and concentrating it using a nanofiltration device with a relative molecular weight cutoff of 1500-2000 Dalton, collecting the concentrate, adding tara gum, xylitol and calcium chloride, and freeze-drying to obtain dietary fiber.

7. The method for preparing brown maltodextrin according to claim 6, characterized in that, The mass ratio of the concentrate, tarara, and calcium chloride is 1:0.5-0.6:0.3-0.

4.

8. Brown maltodextrin prepared by the method according to any one of claims 1-7.