Multi-component coarse grain gradient enzymatic digestion and absorption-promoting food processing method

Abstract

The application discloses a kind of multi-component miscellaneous grains gradient enzymolysis promotion absorption food processing method, belong to food processing technical field.The method includes: S1 raw material pretreatment, miscellaneous grains is removed, washing, soaking, and is made into slurry by grinding pulp;S2 pre-dispensing processing, methyl-β-cyclodextrin, carboxymethyl modified chitosan, basic enzyme component, trehalose alcohol and the like are added to slurry, and mixed to obtain dispensing slurry;S3 step gradient enzymolysis, TG enzyme modified alpha-amylase, saccharifying enzyme, neutral protease, flavour protease are sequentially added, and starch hydrolysis, saccharide hydrolysis and protein hydrolysis are carried out in stages, and enzyme is inactivated after hydrolysis;S4 product preparation, material is filtered, concentrated, and composite granulation component is added, and powder-like miscellaneous grain food is prepared by spray drying combined with low-temperature fluidized bed process.The product obtained by the application has good cold water solubility, is not easy to cake and stratify, has smooth taste, is beneficial to human digestion and absorption, and is suitable for large-scale production and application.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, specifically a multi-component grain gradient enzymatic hydrolysis method for promoting absorption of food. Background Technology

[0002] Whole grains are rich in dietary fiber, vitamins, minerals, and high-quality plant protein, boasting outstanding nutritional value and meeting the demands of modern healthy eating. Related processed products are increasingly attracting market attention. With consumption upgrading, consumers are placing higher demands on the convenience and eating experience of whole grain foods, driving the industry to continuously optimize processing techniques.

[0003] Currently, most whole grain flour processing methods involve steaming, baking, grinding, or simple enzymatic hydrolysis. While enzymatic hydrolysis can improve the digestibility of whole grains, existing technologies often use single enzyme preparations or simple combinations in a one-pot process. The reaction conditions are rudimentary, with significant fluctuations in temperature and pH, making it difficult to match the enzymatic hydrolysis characteristics of different components such as starch and protein. This processing method easily leads to enzyme activity loss and incomplete degradation of macromolecules, affecting product quality stability and making it difficult to balance processing efficiency and edible quality.

[0004] Due to the aforementioned technological limitations, existing whole grain powders suffer from insufficient degradation of starch and protein macromolecules, resulting in limited exposure of hydrophilic groups on the surface. When brewed with cold water, they tend to clump together, forming a hard core that is difficult to disperse. They also exhibit slow dissolution, localized clumping, uneven particle wetting, and settling after standing. Even with prolonged stirring, layering, sedimentation, and a rough texture are common. Warm water preparation also requires a considerable amount of time to achieve even dispersion, failing to meet consumers' needs for quick preparation and immediate consumption in daily, office, or outdoor settings.

[0005] Therefore, there is a need to develop a multi-component grain gradient enzymatic hydrolysis food processing technology that is fully degraded, can be dissolved in cold water in a short time, does not clump, and has a smooth taste, in order to solve the shortcomings of existing processes and meet the market demand for grain foods. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-component grain gradient enzymatic hydrolysis method for food processing to solve problems such as easy loss of enzyme activity, insufficient degradation of macromolecules, poor solubility of products in cold water, easy clumping and layering, and rough taste in the prior art.

[0007] The objective of this invention is achieved through the following technical solution: A method for processing multi-component grain gradient enzymatic hydrolysis for enhanced absorption includes the following steps: S1. Raw material pretreatment: After cleaning, soaking, and grinding the mixed grain raw materials, a mixed grain slurry is made. S2. Pre-mixing treatment: Add methyl-β-cyclodextrin and carboxymethyl modified chitosan to the mixed grain slurry, disperse them fully, add the basic enzyme protection components, stir evenly, and then add trehalose, polyglutamic acid, zinc ions, and magnesium ions. After mixing, the prepared slurry is obtained. The basic enzyme-protecting component is composed of calcium acetate and modified erythritol; the modified erythritol is obtained by coating erythritol with maltodextrin; S3, Stepwise gradient enzymatic hydrolysis: S31. Add TG enzyme-modified α-amylase to the prepared slurry and hydrolyze starch at 50-60℃; S32. After starch hydrolysis, saccharifying enzyme is added, and carbohydrate hydrolysis is carried out at 55-65℃. A tubular molecular sieve membrane with a pore size of 1.0-1.2 nm is installed inside the reaction vessel. The inner cavity of the tubular membrane is connected to an extraction tube, and the outlet end of the extraction tube is connected to a 0.45-0.5 nm pore size filter membrane assembly. The filtrate side of the filter membrane assembly is connected to a reflux tube and returned to the reaction vessel. The reaction vessel is equipped with a glucose concentration sensor, which opens and closes the extraction tube based on the detection result, thereby controlling the glucose concentration in the system to within 8%. S33. After the carbohydrate hydrolysis is complete, add neutral protease and flavor protease, and carry out protein hydrolysis at 45-55℃; inactivate the enzymes after hydrolysis is complete. S4. Finished product preparation: The enzyme-inactivated material is filtered and concentrated. A compound granulation component is added to the concentrated material. After mixing, the mixture is spray-dried and processed using a low-temperature fluidized bed process at 60~70℃ to produce powdered grain food. The composite granulation component is composed of maltodextrin and carboxyl-modified microcrystalline cellulose.

[0008] This invention addresses the problems of poor cold water solubility, easy clumping, sedimentation upon standing, and rough texture of existing whole grain powders by providing a multi-component gradient enzymatic hydrolysis method for promoting the absorption of whole grains. The effects and mechanisms of each step are as follows: In step S1, the grains are first soaked at low temperature, and then ground into a pulp according to a suitable material-to-water ratio to facilitate subsequent enzymatic hydrolysis.

[0009] In step S2, the pretreatment with a compound of methyl-β-cyclodextrin and carboxymethyl-modified chitosan can stably encapsulate functional components such as flavonoids and polysaccharides in grains through bonding, reducing the loss of these substances during processing. Simultaneously, by encapsulating endogenous polyphenols and flavonoids in the grains, their oxidative polymerization is inhibited, preventing oxidation products from affecting the product's color and taste, and reducing the inhibitory effect of oxidation products on enzyme activity. Furthermore, the carboxymethyl modification treatment effectively improves the water solubility of chitosan, reduces the aggregation and adhesion of large molecular materials, and minimizes the adsorption and deposition of materials on the subsequent membrane surface.

[0010] The addition of trehalose, polyglutamic acid, zinc ions, and magnesium ions to the system can stabilize the enzyme molecular structure, slow down the enzyme's thermal inactivation, maintain the morphology of the enzyme's active site, and reduce the impact of temperature fluctuations on enzyme activity.

[0011] Specifically: Calcium acetate releases calcium ions, which stabilize the enzyme's active site structure through chelation, mitigating the decrease in enzyme activity caused by temperature changes and mechanical shearing. Modified erythritol, a maltodextrin-coated erythritol, improves its heat resistance and hygroscopicity, reducing migration under high-temperature conditions; erythritol forms a hydration layer on the enzyme molecule surface, reducing the tendency for enzyme molecule aggregation and maintaining the conformational stability of the enzyme. Trehalose can regulate the system's moisture state, reducing the probability of enzyme dehydration and denaturation; polyglutamic acid, an anionic water-soluble polymer, can moderately thicken the system, stabilize its rheological properties, reduce local concentration gradients, and decrease the deposition and adsorption of macromolecules on the molecular sieve membrane surface. Zinc and magnesium ions, as trace coenzyme factors, optimize the enzymatic hydrolysis microenvironment.

[0012] In step S3, a stepwise gradient enzymatic hydrolysis combined with separate reactor reaction and in-situ glucose removal is used to fully degrade starch, sugars and proteins in the material.

[0013] Specifically, in S31, the TG enzyme mildly modifies the surface of α-amylase, moderately improving the hydrophilicity of the enzyme molecule surface and its substrate binding ability, enhancing its thermal stability, which is beneficial for the efficient cleavage of starch macromolecules and provides small molecule substrates for subsequent saccharification. In S32, the saccharifying enzyme, in conjunction with the molecular sieve, promptly removes the glucose generated in the reaction, weakening the inhibitory effect of the products on the enzyme and improving saccharification efficiency. A 1.0–1.2 nm pore size tubular molecular sieve membrane is installed inside the reaction vessel, trapping large enzyme molecules and unhydrolyzed starch macromolecules within the reaction system. Water, glucose, and inorganic salt ions enter the inner lumen of the tubular membrane and are drawn out through the extraction tube. The discharge end of the extraction tube is connected to a 0.45–0.5 nm pore size filter membrane module. Inorganic salt ions and water are transported back to the reaction vessel from the filtrate side of this filter membrane via the reflux tube, while glucose is trapped on the retention side of the filter membrane module. The reaction vessel is equipped with a glucose concentration sensor; when the glucose concentration in the system exceeds 8%, a sensor will detect the glucose concentration. At this time, the extraction tube is opened to discharge the glucose material, thereby stabilizing the glucose concentration in the system below 8%. This range can significantly weaken the product feedback inhibition. This threshold has been experimentally verified: when the glucose concentration is ≤8%, the glucoamylase inhibition rate is less than 15%, and when it exceeds 8%, the inhibition effect is sharply enhanced, significantly reducing the glucoaming efficiency.

[0014] After saccharification, the protein is hydrolyzed in a separate reaction vessel to avoid the influence of molecular sieves on proteins and hydrolytic enzymes. S33 contains two commonly used proteases to hydrolyze proteins in the material, simplifying the internal protein structure of the material, helping to improve the material's solubility, and optimizing the taste of the finished product.

[0015] In step S4, after the material is filtered and concentrated, a molding excipient composed of maltodextrin and carboxyl-modified microcrystalline cellulose is added. The mixture is then spray-dried using a low-temperature fluidized bed process to obtain a loose, porous powder with uniform particle size. Maltodextrin builds the molding framework, improving the powder's molding effect. Carboxyl-modified microcrystalline cellulose optimizes the powder's wettability and dispersibility in cold water, and, combined with the initial macromolecular degradation effect, reduces particle clumping during cold water preparation, alleviating stratification and sedimentation after preparation. It also optimizes the particle pore structure, accelerating the dissolution rate in cold water. Secondary low-temperature fluidized bed drying improves the powder's surface condition, reduces hard shell formation, alleviates sedimentation upon standing, and optimizes the cold water preparation effect and the taste.

[0016] In summary, the present invention utilizes multiple synergistic processes to effectively solve practical problems such as poor dissolution of mixed grain powder in cold water, easy clumping and layering, and rough texture, making it suitable for large-scale deep processing of mixed grains.

[0017] As some possible implementations of this application, in step S1, the soaking temperature is 20-30°C, and the material-to-water ratio is 1:(5-10); the mixed grain raw materials are selected from at least three of oats, buckwheat, quinoa, black rice, and Job's tears.

[0018] As some possible implementations of this application, in step S2, the amount of carboxymethyl modified chitosan added is 0.1% to 0.2% of the mass of the mixed grain slurry, the total amount of basic enzyme components added is 1.05% to 3.2% of the total mass of the mixed grain slurry, and the mass ratio of calcium acetate to modified erythritol is 1:(8 to 12).

[0019] As some possible implementations of this application, in step S2, the polyglutamic acid is selected with a molecular weight of 200,000 to 400,000 Da; if the molecular weight of polyglutamic acid is too large, the molecular chains are too long and are prone to cross-linking between membrane pores to form bridges, causing membrane blockage; if the molecular weight is controlled at 200,000 to 400,000 Da, excessive gelation with calcium ions can be avoided, and the risk of membrane pore bridging and blockage can be reduced.

[0020] As some possible implementations of this application, in step S3, the amount of α-amylase added is 0.05% to 0.2% of the mass of the mixed grain slurry, the amount of saccharifying enzyme added is 0.1% to 0.3% of the mass of the mixed grain slurry, the amount of neutral protease added is 0.05% to 0.15% of the mass of the mixed grain slurry, and the amount of flavor protease added is 0.03% to 0.1% of the mass of the mixed grain slurry.

[0021] As some possible implementations of this application, in step S33, the enzyme inactivation temperature is 85-95°C and the incubation time is 3-8 minutes.

[0022] As some possible implementations of this application, in step S3, specific enzyme activity protectants are added to each segment of the enzymatic hydrolysis reaction system: sodium bisulfite is added to the α-amylase system, potassium dihydrogen phosphate is added to the saccharifying enzyme system, and cysteine ​​is added to the protease system. Sodium bisulfite can mitigate the impact of the oxidative environment on amylase activity, maintaining the starch hydrolysis process smoothly; potassium dihydrogen phosphate can regulate the acid-base environment of the system, stabilizing the conditions for saccharifying enzyme activity and ensuring the continuous progress of the saccharification reaction; cysteine, as a reducing protectant, can protect the protease from oxidative damage, slowing down the rate of enzyme activity decline during processing, and further improving the overall enzymatic hydrolysis effect.

[0023] As some possible implementations of this application, in step S4, the spray drying inlet air temperature is controlled at 120-140°C, the outlet air temperature is controlled at 75-80°C, and the secondary fluidized drying temperature is set at 60-70°C.

[0024] As some possible implementations of this application, in step S4, the amount of the composite granulation component added is 8% to 15% of the dry basis mass of the concentrated material, wherein the mass ratio of maltodextrin to carboxyl-modified microcrystalline cellulose is (5 to 9): 1; the DE value of the maltodextrin is 15 to 20. In this range, the maltodextrin has moderate solubility, which can stabilize the powder forming structure, avoid the finished product being loose and brittle, and is also suitable for cold water brewing environment, helping the powder to disperse evenly.

[0025] Compared with the prior art, the beneficial effects of the present invention are: This invention achieves a comprehensive effect of deep degradation of macromolecules in grains, stable preservation of enzyme activity, rapid dissolution of powder in cold water, and stable standing by a synergistic process of raw material pretreatment, pre-mixing of enzymes, stepwise gradient enzymatic hydrolysis, and powder modification and molding.

[0026] Tests show that the total starch degradation rate of the whole grain food prepared by this invention can reach over 88.5%, and the degree of protein hydrolysis can reach over 83.1%, with sufficient degradation of macromolecules, which is conducive to human digestion and absorption; the α-amylase activity retention rate is ≥86.0%, the saccharifying enzyme activity retention rate is ≥86.2%, and the protease activity retention rate is ≥85.9%, with stable enzyme activity during the stepwise enzymatic hydrolysis process, ensuring enzymatic hydrolysis efficiency; the cold water solubility is ≥96.1%, and the dispersion stability is ≥94.8%, the powder is not prone to clumping when mixed with cold water, has little back-settling after standing, and has a smooth taste after mixing; the bulk density is moderate, and the powder has good looseness and processing adaptability.

[0027] Compared with the existing simple one-pot enzymatic hydrolysis process, this invention effectively solves the problems of easy loss of enzyme activity, insufficient degradation of macromolecules, poor solubility in cold water, easy clumping and layering, and rough taste. It has good process stability, excellent product quality, and is suitable for large-scale deep processing of miscellaneous grains. Detailed Implementation

[0028] Example 1 1. Preparation method of non-commercially available components.

[0029] (1) Preparation method of modified erythritol: Take 100g of food-grade erythritol (purity ≥99%) and 10g of maltodextrin (DE=18, food grade), and mix them evenly in a stirring vessel; add 25% of the mass of the mixture of purified water, stir at room temperature for 15min until a uniform paste is formed; use laboratory fluidized bed granulation, with an inlet air temperature of 55℃ and an outlet air temperature of 38℃, vacuum dry at 45℃ for 3h after granulation, and pass through a 60-mesh sieve after cooling to obtain modified erythritol.

[0030] (2) Preparation method of TG enzyme modified α-amylase: Take 100g of food grade α-amylase (enzyme activity 10000U / g), add pH 6.5 phosphate buffer to prepare 8% (w / w) enzyme solution; add 2g of food grade TG enzyme (1000U / g) to the enzyme solution, stir at 35℃ and 200r / min for 40min for cross-linking reaction; after the reaction is completed, let stand at 4℃ for 1h to obtain TG enzyme modified α-amylase.

[0031] (3) Preparation of carboxyl-modified microcrystalline cellulose: Take 100g of microcrystalline cellulose (200 mesh), add 500mL of 75% food grade ethanol, stir and disperse at 25℃ and 250r / min for 20min; add 12g of sodium hydroxide, alkalize at 32℃ and 250r / min for 1.5h; slowly add 10g of sodium citrate, stir and react at 52℃ and 250r / min for 2.5h; after the reaction is completed, filter, wash with 70% ethanol until the filtrate is neutral, vacuum dry at 60℃ to constant weight, pulverize and pass through an 80 mesh sieve to obtain carboxyl-modified microcrystalline cellulose.

[0032] 2. Multi-component grain gradient enzymatic hydrolysis for food processing to promote absorption.

[0033] S1 Raw material pretreatment: Take mixed grain raw materials (oats, buckwheat, quinoa, mass ratio 1:1:1), remove impurities manually and wash twice with purified water; put the washed mixed grains into a soaking tank, add purified water, material-to-water ratio 1:8, soak at 25℃ for 8 hours; after soaking, grind with a colloid mill, adjust the grinding gap to 0.1mm, control the material temperature ≤35℃ during grinding, and let stand at 20℃ for 45 minutes after grinding to obtain 80kg of uniform mixed grain slurry.

[0034] S2 Pre-mixing Treatment: Transfer 80 kg of mixed grain slurry into a mixing tank equipped with temperature control and stirring. Turn on the stirring (300 r / min) and control the temperature inside the tank to stabilize at 30℃. Slowly add 0.08 kg of methyl-β-cyclodextrin and 0.08 kg of carboxymethyl modified chitosan (degree of deacetylation ≥90%, degree of substitution 0.4) to the slurry. Then add 0.02 kg of food-grade citric acid to adjust the pH of the system to 5.0-5.5. Stir at 45℃ and 300 r / min for 120 min. After the reaction is complete, adjust the pH back to 7.0 with sodium bicarbonate and continue stirring for 30 min. Then add the basic enzyme protection components (0.20 kg of calcium acetate and 1.60 kg of modified erythritol) to the tank and stir at 30℃ and 300 r / min for 25 min. Then add 0.4 kg of trehalose, 0.2 kg of polyglutamic acid (molecular weight 250,000 Da), and 0.01 kg of... Zinc chloride and 0.01 kg magnesium chloride were heated to 35°C and stirred at a constant temperature of 35°C and 300 r / min for 45 min to obtain the prepared slurry.

[0035] S3 stepwise gradient enzymatic hydrolysis: S31 Starch hydrolysis: Transfer the prepared slurry to a separate starch hydrolysis vessel, start stirring (250 r / min), and heat to 55℃; add 0.08 kg of TG enzyme cross-linked modified α-amylase (pre-dissolved in a small amount of purified water to prepare a 5% enzyme solution) to the vessel, adjust the pH of the system to 6.0 with phosphate buffer, and stir at 55℃ and 250 r / min for 50 min.

[0036] S32 Saccharification Reaction Component Structure: The saccharification reaction adopts an independent saccharification kettle. A set of tubular molecular sieve membranes (alumina-based inorganic ceramic molecular sieve membranes, 8mm inner diameter) is vertically fixed inside the kettle. This membrane only allows water, glucose, and inorganic ions to pass through, while retaining macromolecules such as saccharifying enzymes and unhydrolyzed starch. The inner side of the tubular molecular sieve membrane is connected to an extraction pipe, and the discharge end of the extraction pipe is connected to a 0.45nm filter membrane assembly (inorganic ceramic filter membrane assembly). The filtrate side of the filter membrane assembly is connected to a reflux pipe, which is directly connected to the saccharification kettle to realize the reflux of water and inorganic ions. The saccharification kettle is equipped with an online glucose sensor (detection accuracy ±0.5%) and a PLC controller. A solenoid valve is installed on the extraction pipe. The PLC controller is linked with the sensor, solenoid valve, and micro negative pressure device. The micro negative pressure device is set to a negative pressure value of -0.03MPa. The whole system constitutes a complete sieving, reflux, and control system.

[0037] During saccharification, the stirring device in the saccharification kettle is turned on, and the stirring speed is controlled at 220 r / min to stabilize the reaction temperature at 60℃. 0.16 kg of saccharifying enzyme (enzyme activity 12000 U / g, pre-dissolved in 5% aqueous enzyme solution) is added to the kettle, and the pH of the system is adjusted to 5.0 while maintaining constant temperature and stirring. At the same time, the micro negative pressure device is activated (maintaining a negative pressure of -0.03 MPa). The material passes through the tubular molecular sieve membrane into the extraction tube, and after the flow rate is stabilized by the perforated plate, it is transported to the filter membrane assembly for secondary sieving. The PLC controller receives data from the glucose sensor in real time. When the glucose concentration in the system exceeds 8%, the solenoid valve is automatically opened to discharge the glucose trapped by the filter membrane. When the concentration drops to the standard range, the solenoid valve closes, and the water and inorganic ions separated by the filter membrane return to the saccharification kettle through the reflux pipe, continuously maintaining the stability of the reaction system. The entire reaction process lasts for 75 minutes to ensure that the saccharification reaction is complete and the glucose concentration is controllable.

[0038] S33 Protein Hydrolysis: After the saccharification reaction is complete, all materials in the saccharification vessel are transferred to a separate protein hydrolysis vessel. Stirring is started (200 rpm), and the temperature is lowered to 50°C. 0.08 kg of neutral protease (8000 U / g activity) and 0.05 kg of flavor protease (5000 U / g activity) are added sequentially to the vessel. Both enzymes are pre-dissolved in a 5% aqueous enzyme solution. The pH of the system is adjusted to 7.0, and the mixture is stirred at 50°C and 200 rpm for 75 minutes. Then, the protein hydrolysis vessel is heated to 90°C and held at 180 rpm for 5 minutes. The material is then rapidly cooled to room temperature to complete enzyme inactivation.

[0039] S4 Finished Product Preparation: The enzyme-inactivated material is filtered through a 100-mesh food-grade filter. The filtrate is transferred to a vacuum concentration tank and concentrated at 60℃ and a vacuum of -0.08MPa until the solid content of the material is 30%, obtaining a concentrate. This concentrate is then transferred to a mixing tank, where 1.6 kg of maltodextrin (DE=18) and 0.2 kg of carboxyl-modified microcrystalline cellulose are added under stirring at 25℃ and 250 r / min. Stirring continues at 25℃ and 250 r / min for 30 min. Subsequently, the material is sent to a spray dryer, where the inlet air temperature is controlled at 120℃, the outlet air temperature at 80℃, and the atomization pressure at 0.3MPa for spray drying, and the powder is collected. The resulting powder is then transferred to a low-temperature fluidized bed and dried at a fluidization temperature of 65℃ and a fluidization velocity of 1.2 m / s for 15 min. Afterward, the powder is pasteurized (80℃, 10 min), naturally cooled to room temperature, and then subjected to 80℃ sterilization. The finished grain powder is obtained by sieving.

[0040] Example 2 Based on Example 1, only some parameters were adjusted. The preparation methods and operation steps of the remaining raw materials, non-commercially available components, and other unmentioned raw materials were the same as in Example 1. The specific parameter adjustments are as follows: S1 Raw material pretreatment: soaking temperature 20℃, material-to-water ratio 1:5. S2 Pre-mixing treatment: calcium acetate 0.076kg, modified erythritol 0.764kg; S3 Stepwise gradient enzymatic hydrolysis: α-amylase 0.04kg, saccharifying enzyme 0.08kg, neutral protease 0.04kg, flavor protease 0.024kg; S31 Temperature 50℃, stirring speed 220r / min; S32 Temperature 55℃, stirring speed 200r / min; S33 Temperature 45℃, stirring speed 180r / min; saccharification micro-negative pressure -0.02MPa. S4 Finished product preparation: 8% of composite granulation components were added (0.667 kg of maltodextrin and 0.133 kg of carboxyl-modified microcrystalline cellulose, mass ratio 5:1); maltodextrin DE=15; spray drying inlet air temperature 130℃, outlet air temperature 78℃, atomization pressure 0.25 MPa; fluidization temperature 60℃, air velocity 1.0 m / s.

[0041] Example 3 Based on Example 1, only some parameters were adjusted. The preparation methods and operating steps for the remaining raw materials, non-commercially available components, and other unmentioned materials were the same as in Example 1. Specific parameter adjustments are as follows: S1 Raw material pretreatment: soaking temperature 30℃, material-to-water ratio 1:10. S2 Pre-mixing treatment: 0.016 kg of carboxymethyl modified chitosan. S3 Stepwise gradient enzymatic hydrolysis: 0.16 kg of α-amylase, 0.24 kg of saccharifying enzyme, 0.12 kg of neutral protease, and 0.08 kg of flavor protease. S31 Temperature 60℃, stirring speed 280 r / min; S32 Temperature 65℃, stirring speed 250 r / min; S33 Temperature 55℃, stirring speed 220 r / min; saccharification micro-negative pressure -0.04 MPa. S4 Finished Product Preparation: 15% of composite granulation components were added (1.3125 kg of maltodextrin and 0.1875 kg of carboxyl-modified microcrystalline cellulose, mass ratio 9:1); maltodextrin DE=20; spray drying inlet air temperature 140℃, outlet air temperature 75℃, atomization pressure 0.35 MPa; fluidization temperature 70℃, air velocity 1.5 m / s.

[0042] Example 4 Based on Example 1, only the specific enzyme activity protectant was added. The preparation methods, operation steps, and parameters of the remaining raw materials, non-commercially available components are the same as in Example 1. The specific additions are as follows: S3 Stepwise gradient enzymatic hydrolysis: S31 Starch hydrolysis: Add 0.04 kg sodium bisulfite (dissolved in advance to a 10% aqueous solution); S32 Saccharification reaction: Add 0.08 kg potassium dihydrogen phosphate (dissolved in advance to a 10% aqueous solution); S33 Protein hydrolysis: Add 0.04 kg cysteine ​​(dissolved in advance to a 10% aqueous solution).

[0043] Comparative Example 1 Compared to Example 1, in the S2 pre-mixing treatment, methyl-β-cyclodextrin and carboxymethyl modified chitosan were removed, while the remaining stirring speed, temperature, time, and pH parameters were completely consistent with those in Example 1.

[0044] Comparative Example 2 Compared to Example 1, during the S2 pre-mixing treatment, carboxymethyl modified chitosan was removed, while the remaining stirring speed, temperature, time, and pH parameters were completely consistent with those of Example 1.

[0045] Comparative Example 3 Compared to Example 1, in the S2 pre-mixing treatment, the basic protective enzyme component was removed, while the remaining stirring speed, temperature, time, and pH parameters were completely consistent with those in Example 1.

[0046] Comparative Example 4 Compared to Example 1, in the S2 pre-mixing treatment, the modified erythritol was replaced with an equal mass of ordinary erythritol (uncoated), while the remaining components, preparation, process steps, and parameters were completely consistent with Example 1.

[0047] Comparative Example 5 Compared to Example 1, in the S2 pre-mixing treatment, trehalose and polyglutamic acid were removed, while the remaining components, preparation, process steps, and parameters were completely consistent with Example 1.

[0048] Comparative Example 6 Compared to Example 1, in the S31 starch hydrolysis, the TG enzyme-modified α-amylase was removed and replaced with an equal mass of ordinary α-amylase (without cross-linking modification). The remaining enzymatic hydrolysis, process steps, and parameters were completely consistent with Example 1.

[0049] Comparative Example 7 Compared to Example 1, in the S32 saccharification reaction, the glucose-specific molecular sieve membrane and the matching micro-negative pressure sugar removal device are eliminated, and glucose is not removed in situ during the saccharification process. The remaining saccharification temperature, stirring speed, and time parameters are completely consistent with those in Example 1.

[0050] Comparative Example 8 Compared to Example 1, in the preparation of S4 product, the carboxyl-modified microcrystalline cellulose was replaced with an equal mass of ordinary microcrystalline cellulose (unmodified), while the other granulation ratio, stirring speed, drying and other parameters were completely consistent with those in Example 1.

[0051] Comparative Example 9 Compared to Example 1, S4 omits the step of transferring to a low-temperature fluidized bed for drying, and the entire process is carried out by spray drying. The remaining component ratios, stirring speeds, temperatures, times, and pH parameters are completely consistent with those of Example 1.

[0052] Comparative Example 10 Compared to Example 1, in the stepwise gradient enzymatic hydrolysis of S3, the separate starch hydrolysis vessel, saccharification vessel, and protein hydrolysis vessel were eliminated. TG enzyme-modified α-amylase, saccharifying enzyme, neutral protease, and flavor protease were added to the same reaction vessel at once and enzymatically hydrolyzed simultaneously at 53°C and 220 r / min for 240 min. Furthermore, a dedicated glucose molecular sieve membrane and a matching micro-negative pressure sugar removal device were not installed. The remaining subsequent process steps and parameters, such as enzyme inactivation, concentration, and drying, were completely consistent with those in Example 1.

[0053] Experimental Example To verify the effectiveness of the multi-component gradient enzymatic hydrolysis method for promoting the absorption of grains in this invention, experiments were conducted on Examples 1-4 and Comparative Examples 1-10. All experiments were repeated three times in parallel, with a relative standard deviation (RSD) ≤ 5%. The average value was taken as the final result (as shown in Table 1). Specific detection indicators and methods are as follows: (1) Indicators related to enzymatic hydrolysis and absorption: ① Total starch degradation rate: Glucose discharged from molecular sieve during saccharification is collected and combined with residual reducing sugar in the feed solution after enzymatic hydrolysis. The total mass of reducing sugar generated is determined by DNS colorimetric method. Total starch degradation rate = (total mass of reducing sugar generated / total mass of raw starch) × 100%. The higher the value, the more complete the starch degradation and the easier it is to absorb.

[0054] ② Degree of protein hydrolysis: The soluble nitrogen content before and after hydrolysis was determined by the Kjeldahl method. Degree of protein hydrolysis = (mass of soluble nitrogen after hydrolysis / mass of total nitrogen in raw material) × 100%. The higher the value, the more complete the protein hydrolysis and the better the absorption rate.

[0055] ③ Enzyme activity retention rate: Each enzyme was sampled and measured separately after the completion of its corresponding enzymatic hydrolysis step and before the material was transferred to the next reactor. α-Amylase activity retention rate: Samples were taken after starch hydrolysis was completed in S31 and before the material was transferred to the saccharification reactor; enzyme activity retention rate = (remaining α-amylase activity ÷ initial added α-amylase activity) × 100%; Saccharifying enzyme activity retention rate: Sampling was performed after saccharification in S32 and before the material was transferred to the protein hydrolysis reactor; Enzyme activity retention rate = (remaining saccharifying enzyme activity ÷ initial added saccharifying enzyme activity) × 100%; Protease activity retention rate: S33 Sample taken after protein hydrolysis and before enzyme inactivation; enzyme activity retention rate = (remaining protease activity ÷ initial added protease activity) × 100%.

[0056] (2) Physicochemical and reconstitution properties of the powder: ① Bulk density: Using the graduated cylinder method, take 10g of powder and let it fall freely into a 100mL graduated cylinder. After gently shaking, read the volume. Bulk density = powder mass / volume, unit g / mL.

[0057] ② Cold water solubility: Take 5g of powder and add 50mL of room temperature water (25℃), stir magnetically for 30s at 300r / min, pass through a 100-mesh food-grade standard sieve, and weigh the mass of insoluble matter on the sieve. Cold water solubility = (5g - mass of insoluble matter) / 5g × 100%; if the solubility within 30s is ≥95%, it is judged as rapid dissolution. The higher the value, the better the solubility and the less clumping.

[0058] ③ Dispersion stability: Take another 5g of finished powder, add 50mL of room temperature water (25℃), and stir magnetically (400r / min) until there are no visible particles, no clumps, and a uniform emulsion. For samples that are difficult to dissolve and still have obvious particles or clumps, the temperature can be gradually increased to 40-50℃ and stirred for a short time to aid dissolution until the above uniform state is achieved. For samples dissolved at room temperature: after stopping stirring, place them directly in a room temperature environment and let them stand for 30 minutes; For samples that have been heated to aid dissolution: after stopping stirring, immediately place the sample in a flowing room temperature water bath to cool it through the wall and let it stand for 30 minutes without disturbing the solution during the cooling process; After all samples were allowed to stand for 30 minutes, the total liquid layer height and the bottom sediment layer height were recorded; the calculation formula was: Dispersion stability = (Total liquid layer height) / (Sedimentation stability) * ... The higher the value of (sedimentation layer height) / total liquid layer height × 100%, the less back settling occurs and the better the stability.

[0059] Table 1: Performance test results of Examples 1-4 and Comparative Examples 1-10 As can be seen from Table 1: Examples 1-3 represent the preferred process schemes of this invention, which effectively achieve comprehensive effects such as complete degradation of starch and protein in miscellaneous grains, stable retention of the activities of three types of enzymes, rapid dissolution of powder in cold water, and stability after standing. Their overall performance is significantly superior to that of the comparative examples. Specifically, the total starch degradation rate is ≥88.5%, and the degree of protein hydrolysis is ≥83.1%, indicating complete degradation of macromolecules; the α-amylase activity retention rate is ≥86.0%, the saccharifying enzyme activity retention rate is ≥86.2%, and the protease activity retention rate is ≥85.9%, indicating stable enzyme activity during the stepwise enzymatic hydrolysis process; the cold water solubility is ≥96.1%, and the dispersion stability is ≥94.8%, indicating that the powder is not prone to clumping when mixed with cold water, has minimal back-settling after standing, and has a smooth taste after mixing; the bulk density is moderate, and the powder has good looseness and processing adaptability.

[0060] Example 4: Based on Example 1, a dedicated enzyme activity protectant was added, which improved the retention rates of α-amylase, saccharifying enzyme, and protease activities, demonstrating the positive benefit of the enzyme protection component on enzyme activity stability and enzymatic hydrolysis efficiency.

[0061] In Comparative Example 1, the removal of methyl-β-cyclodextrin and carboxymethyl modified chitosan resulted in the inability to effectively protect functional components and stabilize the enzymatic hydrolysis microenvironment, leading to a decrease in enzyme activity retention, weakened starch and protein degradation, and poorer powder solubility and stability. In Comparative Example 2, the removal of carboxymethyl modified chitosan weakened the system's stabilizing effect on the enzyme structure, significantly reduced enzyme activity, incomplete macromolecular degradation, and decreased reconstitution performance. In Comparative Example 3, the removal of the basic enzyme-protecting component resulted in the loss of enzyme-protecting effects from calcium ions and modified erythritol, leading to a decrease in the retention rates of all three types of enzymes and a significant decline in overall enzymatic hydrolysis performance. In Comparative Example 4, replacing modified erythritol with ordinary erythritol weakened the slow-release enzyme-protecting ability, decreased enzyme activity stability, reduced starch degradation efficiency, and poorer powder reconstitution stability. In Comparative Example 5, the removal of trehalose and polyglutamic acid significantly increased system viscosity, hindered enzymatic hydrolysis mass transfer, weakened enzyme molecule protection, and reduced enzyme activity retention. In Comparative Example 6, the use of ordinary α-amylase instead of TG-modified α-amylase resulted in decreased thermostability and shear resistance of the amylase, leading to the lowest α-amylase activity retention rate among all groups and a significant reduction in starch degradation. In Comparative Example 7, the removal of the glucose molecular sieve removal device significantly inhibited product feedback, drastically reducing the saccharifying enzyme activity retention rate, lowering saccharification efficiency, and worsening overall degradation. In Comparative Example 8, the replacement of carboxyl-modified microcrystalline cellulose with ordinary microcrystalline cellulose weakened the cold water wetting and dispersibility of the powder, decreasing cold water solubility and dispersion stability. In Comparative Example 9, the removal of low-temperature fluidized bed drying resulted in higher powder particle density, insufficient pore structure, slower cold water dissolution rate, and increased settling. In Comparative Example 10, the elimination of stepwise gradient enzymatic hydrolysis and the adoption of a single-pot simultaneous enzymatic hydrolysis resulted in no glucose removal and inter-enzyme interference, leading to severe enzyme activity loss, incomplete macromolecular degradation, and poor powder solubility and stability.

Claims

1. A method for processing multi-component grain gradient enzymatic hydrolysis for enhanced absorption, characterized by comprising the following steps: S1. Raw material pretreatment: After cleaning, soaking, and grinding the mixed grain raw materials, a mixed grain slurry is made. S2. Pre-mixing treatment: Add methyl-β-cyclodextrin and carboxymethyl modified chitosan to the mixed grain slurry, disperse them fully, add the basic enzyme protection components, stir evenly, and then add trehalose, polyglutamic acid, zinc ions, and magnesium ions. After mixing, the prepared slurry is obtained. The basic enzyme-protecting component is composed of calcium acetate and modified erythritol; the modified erythritol is obtained by coating erythritol with maltodextrin; S3, Stepwise gradient enzymatic hydrolysis: S31. Add TG enzyme-modified α-amylase to the prepared slurry and hydrolyze starch at 50-60℃; S32. After starch hydrolysis is complete, add saccharifying enzyme and hydrolyze the carbohydrates at 55–65°C; the reaction vessel for this step is equipped with... A tubular molecular sieve membrane with a pore size of 1.0–1.2 nm is used. The inner cavity of the tubular membrane is connected to an extraction tube, and the discharge end of the extraction tube is connected to a filtration membrane module with a pore size of 0.45–0.5 nm. The filtrate side of the filtration membrane module is connected to a reflux tube and then back to the reaction vessel. The reaction vessel is equipped with a glucose concentration sensor, which opens and closes the extraction tube based on the detection result, thereby controlling the glucose concentration in the system to within 8%. S33. After the carbohydrate hydrolysis is complete, add neutral protease and flavor protease, and carry out protein hydrolysis at 45-55℃; inactivate the enzymes after hydrolysis is complete. S4. Finished product preparation: The enzyme-inactivated material is filtered and concentrated. A compound granulation component is added to the concentrated material, and after mixing, it is spray-dried and fluidized bed process to produce powdered grain food. The composite granulation component is composed of maltodextrin and carboxyl-modified microcrystalline cellulose.

2. The multi-component grain gradient enzymatic hydrolysis method for promoting absorption of food according to claim 1, characterized in that, In step S1, the soaking temperature is 20-30℃ and the material-to-water ratio is 1:(5-10); the mixed grain raw materials are selected from at least three of the following: oats, buckwheat, quinoa, black rice, and Job's tears.

3. The multi-component grain gradient enzymatic hydrolysis method for food processing according to claim 1, characterized in that, In step S2, the amount of carboxyl-modified chitosan added is 0.1% to 0.2% of the mass of the mixed grain slurry, and the total amount of basic enzyme components added is 1.05% to 3.2% of the total mass of the mixed grain slurry; the mass ratio of calcium acetate to modified erythritol is 1:(8 to 12).

4. The multi-component grain gradient enzymatic hydrolysis method for food processing according to claim 1, characterized in that, In step S2, the polyglutamic acid is selected with a molecular weight of 200,000 to 400,000 Da.

5. The multi-component grain gradient enzymatic hydrolysis method for promoting absorption of food according to claim 1, characterized in that, In step S3, the amount of α-amylase added is 0.05% to 0.2% of the mass of the mixed grain slurry, the amount of saccharifying enzyme added is 0.1% to 0.3% of the mass of the mixed grain slurry, the amount of neutral protease added is 0.05% to 0.15% of the mass of the mixed grain slurry, and the amount of flavor protease added is 0.03% to 0.1% of the mass of the mixed grain slurry.

6. The multi-component grain gradient enzymatic hydrolysis method for food processing according to claim 1, characterized in that, In step S33, the enzyme inactivation temperature is 85–95°C, and the incubation time is 3–8 min.

7. The multi-component grain gradient enzymatic hydrolysis method for food processing according to claim 1, characterized in that, In step S3, specific enzyme activity protectants are added to each enzymatic reaction system: sodium bisulfite is added to the α-amylase system, potassium dihydrogen phosphate is added to the saccharifying enzyme system, and cysteine ​​is added to the protease system.

8. The multi-component grain gradient enzymatic hydrolysis method for promoting absorption of food according to claim 1, characterized in that, In step S4, the inlet air temperature of the spray dryer is controlled at 120-140℃, the outlet air temperature is controlled at 75-80℃, and the secondary fluidized drying temperature is set at 60-70℃.

9. The multi-component grain gradient enzymatic hydrolysis method for food processing according to claim 1, characterized in that, In step S4, the amount of the composite granulation component added is 8% to 15% of the dry basis mass of the concentrated material, wherein the mass ratio of maltodextrin to carboxyl-modified microcrystalline cellulose is (5 to 9):1; and the DE value of the maltodextrin is 15 to 20.

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