A method for preparing cereal food therapy peptides by three-step enzymolysis and a product thereof

Abstract

This invention discloses a three-step enzymatic hydrolysis method for preparing cereal-based therapeutic peptides and the resulting product, belonging to the field of food biotechnology. Addressing the problems of insufficient hydrolysis, long cycle time, strong bitterness, significant nutrient loss, and low activity in existing technologies, this invention employs a three-step synergistic enzymatic hydrolysis process: starch hydrolysis, proteolysis and flavor debittering, and saccharification hydrolysis. Combined with ambient pressure and gentle enzyme inactivation and purification steps, this achieves efficient preparation of small molecule peptides and optimized taste. This invention shortens the process cycle from the traditional 10 hours to 6 hours, increasing efficiency by 40%. The resulting therapeutic peptides have a molecular weight mainly below 3000 Da, with a peptide yield increase of 15%–25%, a debittering rate >60%, and a sweet taste with no bitterness, retaining complete nutrition and activity. The process is stable, operates under ambient pressure, and is easy to industrialize. This invention is applicable to single or compound cereal raw materials such as corn, oats, and millet, and can be widely used in the field of therapeutic and nutritional foods.

Description

Technical Field

[0001] This invention belongs to the field of food biotechnology, and specifically relates to a three-step enzymatic hydrolysis method for preparing cereal therapeutic peptides and the product thereof. Background Technology

[0002] Grains are the most basic and important source of energy and nutrition in the human diet. They are rich in high-quality plant protein, starch, minerals, vitamins, fatty acids, nucleosides, carotenoids, plant polyphenols, ferulic acid, and other nutrients and natural bioactive components. With their wide availability, low price, and high safety, they are an ideal raw material for preparing therapeutic nutritional peptides. Modern enzymatic hydrolysis technology can directionally degrade the large molecular structure of proteins in grains into small molecule active peptides. These small molecule peptides have various therapeutic and health-promoting functions, including easy absorption in the gastrointestinal tract, high-efficiency antioxidant properties, bidirectional immune regulation, auxiliary blood pressure lowering, and rapid anti-fatigue effects. This aligns with current consumer demand for natural, nutritious, healthy, and functional foods, and has broad market application prospects and industrialization value in the fields of functional foods, special medical purpose formula foods, dietary supplements, and health foods.

[0003] Currently, the industrial preparation technology for cereal bioactive peptides mainly relies on single or double enzymatic hydrolysis processes. However, these processes suffer from several insurmountable technical drawbacks in practical production and product quality control: First, single or double enzymatic hydrolysis processes result in insufficient degradation of cereal proteins and starches, low substrate conversion rates, and low yields of small-molecule bioactive peptides, leading to a waste of high-quality cereal raw materials and increased production costs. Second, conventional enzymatic hydrolysis processes generate large amounts of hydrophobic bitter peptides, resulting in a distinctly bitter taste in the final product, extremely poor palatability, and failure to meet the taste requirements for food applications. This has become a common pain point hindering the industrialization of cereal-based therapeutic peptides. Third, traditional enzymatic hydrolysis processes are time-consuming. The process is lengthy, generally requiring 8–12 hours to complete the full degradation reaction, resulting in low production efficiency, high energy consumption, high time costs, and low equipment utilization in industrial production. Fourth, existing processes mostly employ high-temperature and high-pressure enzyme inactivation, and the harsh enzyme inactivation conditions easily trigger Maillard browning reactions in the materials, causing a large loss of heat-sensitive nutrients and a significant reduction in the bioactivity of dietary peptides, seriously affecting product quality and functional effects. Fifth, the process design lacks a systematic step-by-step synergistic enzymatic hydrolysis approach, and the two core substrates, starch and protein, cannot be degraded simultaneously and efficiently. The system has poor fluidity and limited enzymatic hydrolysis efficiency, making it difficult to achieve stable and standardized preparation of high-quality, high-activity, and high-tasting cereal dietary peptides.

[0004] To address the long-standing technical challenges in the aforementioned industries and overcome existing process bottlenecks, this invention provides a three-step continuous enzymatic hydrolysis method for preparing cereal therapeutic peptides, which simultaneously debitteres and mildly inactivates enzymes under normal pressure. This method achieves efficient degradation, debittering at the source, natural sweetening, and mild preservation of activity through three synergistic enzymatic hydrolysis steps, comprehensively compensating for the shortcomings of existing technologies and promoting the industrial production and food application upgrade of cereal therapeutic peptides. Summary of the Invention

[0005] In view of this, the present invention provides a three-step enzymatic hydrolysis method for preparing cereal therapeutic peptides and the product thereof, in order to solve or alleviate one of the technical problems existing in the prior art, and at least provide a beneficial alternative.

[0006] The technical solution of this invention is implemented as follows: a three-step enzymatic hydrolysis method for preparing cereal therapeutic peptides and its products, comprising six core steps: raw material processing and pulping, starch enzymatic hydrolysis, proteolytic hydrolysis and simultaneous debittering with flavor enzymes, saccharification enzymatic hydrolysis, enzyme inactivation under normal pressure, and refining. The raw material processing and pulping involves color sorting, impurity removal, crushing, and irradiation of grains, followed by adding water and stirring to obtain a grain extract; the starch enzymatic hydrolysis involves adjusting the temperature and pH, then adding amylase to degrade starch into dextrins and oligosaccharides to improve the fluidity of the system. The simultaneous debittering by proteolysis and flavor enzymes involves simultaneously adding protease and flavor enzymes to degrade the protein into small molecule therapeutic peptides and remove the hydrophobic ends to achieve debittering at the source. The saccharification and enzymatic hydrolysis involves adding saccharifying enzymes to convert residual dextrins and oligosaccharides into reducing sugars to enhance sweetness and palatability; the atmospheric pressure enzyme inactivation involves gently terminating the reaction at 100°C, atmospheric pressure, and 0 MPa gauge pressure for 10–30 minutes. The refining process involves filtration, simultaneous separation of liquid and residue, homogenization, concentration, or drying to obtain therapeutic peptide products. The method employs a three-step synergistic enzymatic hydrolysis process with a cycle of 6 hours, which is 40% more efficient than the traditional 8–12 hour process. The resulting product has a molecular weight mainly below 3000 Da, a peptide yield increase of 15%–25%, and a debittering rate of >60%.

[0007] Furthermore, the grain raw material is any one of corn, oats, and millet, or a compound grain composed of oats and corn in a mass ratio of 1:1; the grain particle size after pulverization is 60 mesh or 80 mesh. In the raw material processing and pulping steps, the material-to-liquid ratio is 1:8, 1:9, or 1:10, and the added water is purified water. After stirring, a uniform and stable grain extract is formed. Irradiation treatment can kill microorganisms on the surface of the raw materials and reduce the content of anti-nutritional factors in the raw materials, thereby improving the efficiency of subsequent enzymatic hydrolysis and the hygiene and safety of the products.

[0008] Furthermore, in the starch enzymatic hydrolysis step, the hydrolysis temperature is 85℃ or 90℃, and the pH is adjusted to 5.5 or 6.0; The added amylase is α-amylase or thermostable amylase, and the amount added is 0.5‰ or 0.6‰ of the dry weight of the raw material; The enzymatic hydrolysis time is 60 or 70 minutes, which fully degrades starch into dextrin and oligosaccharides, reduces system viscosity, improves system fluidity, and provides more space for proteases and flavor enzymes to function, achieving synergistic and efficient degradation of starch and protein.

[0009] Furthermore, in the step of simultaneous debittering with protease hydrolysis and flavor enzymes, the hydrolysis temperature is 53°C or 55°C, and the pH is adjusted to 6.5 or 7.0. The protease is a neutral or alkaline protease, and the amount added is 0.1‰ or 0.3‰ of the dry weight of the raw material; The amount of flavor enzyme added is 0.2‰ or 0.25‰ of the dry weight of the raw materials; The simultaneous enzymatic hydrolysis time is 2 or 3 hours, which simultaneously completes the directional degradation of protein macromolecules into small molecule therapeutic peptides and the terminal removal of hydrophobic bitter peptides, blocking the production of bitterness from the source and achieving a stable debittering effect without bitterness.

[0010] Furthermore, in the saccharification and enzymatic hydrolysis step, the enzymatic hydrolysis temperature is kept consistent with the proteolytic hydrolysis temperature at 53°C or 55°C. The amount of saccharifying enzyme added is 0.1‰ or 0.3‰ of the dry weight of the raw materials; the enzymatic hydrolysis time is 1.5 hours or 2 hours. It completely converts the dextrin and oligosaccharides remaining after starch enzymatic hydrolysis into reducing sugars such as glucose. It can achieve a natural sweet taste without the need to add sucrose, sweeteners or other exogenous ingredients, thereby improving the palatability and food safety of the product.

[0011] Furthermore, the enzyme inactivation step under normal pressure is strictly controlled at a temperature of 100°C, a pressure of normal pressure and a gauge pressure of 0 MPa, and an inactivation time of 15 or 20 minutes. This gentle enzyme inactivation method avoids Maillard browning of materials, loss of heat-sensitive nutrients and reduction of bioactivity of therapeutic peptides caused by high temperature and high pressure, thus fully preserving the inherent nutrition and small molecule peptide functional activity of the grain raw materials.

[0012] Furthermore, in the refining step, the liquid and slag are separated simultaneously using a 140-mesh filter to effectively remove raw material fibers and insoluble residues. After separation, high-pressure homogenization is performed to improve product uniformity and stability. Depending on the product form requirements, homogenization directly yields cereal-based dietary peptide liquid, or vacuum concentration and spray drying yields cereal-based dietary peptide powder. The separation, homogenization, concentration, and drying processes are all gentle physical treatments that do not damage the structure and bioactivity of small molecule peptides.

[0013] Furthermore, the three-step synergistic enzymatic hydrolysis involves starch hydrolysis, proteolysis and flavor debittering, and saccharification hydrolysis proceeding sequentially without intermediate pauses, repeated temperature control, or material transfer. Starch degradation and protein degradation proceed simultaneously, addressing the industry's technical shortcomings of incomplete degradation, low substrate utilization, and low yield of small molecule peptides caused by single or dual enzymatic hydrolysis.

[0014] Furthermore, the product is in liquid or powder form, and the raw material is single grain or compound grain; the molecular weight of the product is mainly distributed below 3000 Da, with high content of small molecule peptides, a debittering rate of >60%, a sweet taste without bitterness, and good palatability. It has dietary therapy functions such as easy absorption, anti-oxidation, immune regulation, blood pressure reduction, and anti-fatigue. The nutrients and active ingredients are completely preserved, and it can be eaten directly or used as a raw material for functional foods.

[0015] Furthermore, the product is corn-based therapeutic peptide liquid, oat-corn compound therapeutic peptide powder, or millet-based therapeutic peptide liquid; Corn-based therapeutic peptide liquid uses corn as a single ingredient, oat-corn compound therapeutic peptide powder uses oat and corn in a 1:1 ratio as raw materials, and millet-based therapeutic peptide liquid uses millet as a single ingredient. The product manufacturing process operates entirely under normal pressure, uses universal equipment, has low energy consumption, high safety, and stable and controllable parameters, making it suitable for large-scale continuous industrial production.

[0016] The embodiments of the present invention have the following advantages due to the adoption of the above technical solutions: 1. Three-step synergistic degradation significantly improves production efficiency: The process adopts a three-step continuous synergistic process of starch enzymatic hydrolysis, proteolytic hydrolysis and flavor debittering, and saccharification enzymatic hydrolysis. Starch and protein are degraded simultaneously and efficiently, substrate utilization is significantly improved, the process cycle is shortened from the traditional 10 hours to 5 hours, production efficiency is increased by 40%, and time cost, energy cost and equipment occupation cost are significantly reduced.

[0017] Simultaneous debittering with flavor enzymes solves the industry's taste pain point: Protease and flavor enzyme work simultaneously to precisely remove the ends of hydrophobic bitter peptides from the source, completely eliminating the bitterness of the product. The debittering rate is >60%, and the product has a sweet and palatable taste, fully meeting the taste requirements of food applications and breaking through the common technical bottlenecks in the industry.

[0018] Natural sweetening through saccharification and enzymatic hydrolysis, with no additional additives: residual oligosaccharides are converted into reducing sugars by saccharifying enzymes, achieving a natural sweet flavor. There is no need to add exogenous ingredients such as sucrose, artificial sweeteners, or flavoring agents, making the product more natural, healthier, and safer, in line with modern food consumption trends.

[0019] Normal pressure and gentle enzyme inactivation preserve nutritional activity: Enzymes are inactivated at 100℃ under normal pressure, avoiding browning, nutrient loss and reduced activity caused by high temperature and high pressure. This fully preserves the vitamins, minerals, plant polyphenols and other nutrients and bioactive peptides in the grains, resulting in superior product quality.

[0020] The process is stable and controllable, making it suitable for industrial production: the entire process is operated under normal pressure, the equipment is highly versatile, easy to operate, the parameters are stable and controllable, the energy consumption is low, the safety is high, no special high-pressure equipment is required, it is suitable for large-scale industrial continuous production, and the industrialization threshold is lowered.

[0021] The product is of excellent quality and has clear therapeutic functions: the molecular weight of the obtained therapeutic peptides is mainly distributed below 3000 Da, small molecule peptides are easily absorbed, peptide yield is increased by 15%-25%, and it has clear therapeutic functions such as anti-oxidation, immune regulation, blood pressure reduction and anti-fatigue. The product has good stability, good palatability and wide range of applications.

[0022] The above overview is for illustrative purposes only and is not intended to be limiting in any way. Further aspects, embodiments, and features of the invention will become apparent from the following detailed description, in addition to the illustrative aspects, embodiments, and features described above. Detailed Implementation

[0023] Example 1: Preparation of Corn Therapeutic Peptide Liquid 1. Raw material processing and pulping: Select high-quality yellow corn raw materials, remove impurities such as moldy kernels, broken kernels, stones, and weeds by color sorting, mechanically crush to 80 mesh fineness, and irradiate sterilize to kill surface microorganisms; add food-grade pure water at a material-to-liquid ratio of 1:8, and stir at high speed until the materials are completely dispersed and uniform to obtain corn extract without lumps or stratification.

[0024] Starch hydrolysis: The corn extract was pumped into the hydrolysis tank and heated to 90°C. The pH was adjusted to 6.0 with a food-grade acid-base regulator. 0.5‰ of the dry weight of the raw material α-amylase was added and the mixture was stirred at a constant temperature for 60 minutes to fully degrade the starch into dextrin and oligosaccharides, reduce the viscosity of the system, improve the fluidity of the system, and create favorable conditions for subsequent proteolytic hydrolysis.

[0025] Enzymatic hydrolysis and flavor debittering: After starch enzymatic hydrolysis, heating is stopped and the temperature is allowed to drop naturally to 55°C. The pH is adjusted to 7.0, and neutral protease (0.4‰ of the dry weight of the raw material) and flavor enzyme (0.3‰ of the dry weight of the raw material) are added simultaneously. The mixture is stirred at a constant temperature for 3 hours to enzymatically hydrolyze the corn protein macromolecules into small molecule therapeutic peptides. At the same time, the ends of hydrophobic bitter peptides are removed to eliminate bitterness from the source.

[0026] Saccharification and enzymatic hydrolysis: Keep the enzymatic hydrolysis temperature constant at 55℃, add 0.3‰ of the dry weight of the raw material with saccharifying enzyme, and continue to stir at a constant temperature for 2 hours to completely convert the dextrin and oligosaccharides remaining after starch enzymatic hydrolysis into reducing sugars such as glucose, giving the product a natural sweet taste.

[0027] Enzyme inactivation under normal pressure: After the enzymatic hydrolysis reaction is completed, the system is heated to 100°C and the enzyme is inactivated at a constant temperature for 15 minutes under normal pressure and 0 MPa gauge pressure. This gently terminates all enzymatic reactions and avoids the loss of nutrients and activity caused by high temperature and high pressure.

[0028] Refining: After enzyme inactivation, the mixture is naturally cooled to room temperature and then simultaneously separated into liquid and residue through a 140-mesh sieve to remove insoluble fibers and residues. The separated liquid is then subjected to high-pressure homogenization to improve uniformity and stability, ultimately yielding a corn-based therapeutic peptide liquid with a sweet taste, no bitterness, and high content of small molecule peptides. The resulting product has a molecular weight mainly below 3000 Da, a 20% increase in peptide yield, a debittering rate of >60%, and complete retention of nutrients and active ingredients.

[0029] Example 2: Preparation of Oat-Corn Compound Therapeutic Peptide Powder 1. Raw material processing and pulping: Select high-quality peeled oats and yellow corn raw materials, mix them precisely at a mass ratio of 1:1, remove impurities and unqualified particles by color sorting and air sorting, mechanically pulverize to 60 mesh fineness, and sterilize by irradiation; add food-grade purified water at a material-liquid ratio of 1:10, stir thoroughly until uniformly mixed, and obtain oat-corn mixed grain extract.

[0030] Starch hydrolysis: Heat the mixed extract to 85℃, adjust the pH to 5.5, add 0.6‰ of the dry weight of the raw material with heat-resistant amylase, and stir at a constant temperature for 70 minutes to fully degrade starch into dextrin and oligosaccharides, improve the fluidity of the system, and enhance the efficiency of subsequent enzymatic hydrolysis.

[0031] Enzymatic hydrolysis and flavor debittering: Cool to 53℃, adjust pH to 6.5, and simultaneously add 0.3‰ of alkaline protease and 0.2‰ of flavor enzyme by dry weight of raw materials. Stir at constant temperature and perform simultaneous enzymatic hydrolysis for 2.5 hours to complete the degradation of complex cereal protein and the simultaneous removal of bitter peptides, ensuring that the product has no bitter taste.

[0032] Saccharification and enzymatic hydrolysis: Keep the temperature constant at 53℃, add 0.25‰ of the dry weight of the raw materials with saccharifying enzyme, stir at a constant temperature for 1.5 hours to completely convert the residual dextrin and oligosaccharides into reducing sugars, thereby improving the natural sweetness and palatability of the product.

[0033] Enzyme inactivation at atmospheric pressure: Heat to 100℃ and inactivate the enzyme at atmospheric pressure and gauge pressure of 0MPa for 20 minutes to completely terminate the enzymatic reaction and gently preserve its activity.

[0034] Refining: After enzyme inactivation and cooling, the mixture is filtered through a plate and frame filter and simultaneously separated from the solid residue using a 140-mesh filter to remove solid residue. The separated liquid is then homogenized under high pressure and concentrated under vacuum until the solid content meets the standard. It is then spray-dried into powder to obtain oat-corn compound dietary peptide powder. The molecular weight of the product is mainly distributed below 3000 Da, the peptide yield is increased by 25%, the debittering rate is >65%, the taste is sweet, the solubility is good, the flowability is strong, and the nutrition and bioactivity are completely preserved, making it suitable for use as a food ingredient and dietary supplement.

[0035] Example 3: Preparation of Millet Therapeutic Peptide Liquid 1. Raw material processing and pulping: Select high-quality millet raw materials, remove impurities such as sand, husks and moldy grains by color sorting, mechanically crush to 60 mesh fineness, and sterilize by irradiation; add food-grade pure water at a material-to-liquid ratio of 1:9, and stir thoroughly to form a uniform millet extract without sediment.

[0036] Starch hydrolysis: Heat the millet extract to 90℃, adjust the pH to 6.0, add 0.5‰ of the dry weight of the raw material with α-amylase, and stir at a constant temperature for 60 minutes to fully degrade the starch into dextrin and oligosaccharides, reduce the viscosity of the system, and improve the stability of the enzymatic hydrolysis system.

[0037] Enzymatic hydrolysis and flavor debittering: Cool to 55℃, adjust pH to 7.0, and simultaneously add 0.2‰ of the dry weight of the raw material neutral protease and 0.3‰ of the flavor enzyme. Stir at a constant temperature for 3 hours to degrade millet protein into small molecule therapeutic peptides and simultaneously remove the bitter end, thus achieving debittering at the source.

[0038] Saccharification and enzymatic hydrolysis: Keep the temperature constant at 55℃, add 0.2‰ of the dry weight of the raw materials with saccharifying enzyme, stir at a constant temperature for 2 hours to completely convert the residual oligosaccharides into reducing sugars, giving the product a natural sweet flavor.

[0039] Enzyme inactivation under normal pressure: The enzyme is inactivated at 100℃, normal pressure, and 0MPa gauge pressure for 15 minutes, which gently terminates all enzymatic reactions and protects nutrients and active ingredients.

[0040] Refining: After cooling to room temperature, the mixture is filtered and the liquid and residue are separated simultaneously through a 140-mesh screen to remove insoluble residues. The separated liquid is then homogenized under high pressure to obtain millet dietary peptide liquid. The molecular weight of the product is mainly distributed below 3000 Da, the peptide yield is increased by 15%, the debittering rate is >60%, the taste is sweet, the color is uniform, the nutrients are rich, and the biological activity is high. It is suitable for direct consumption or use as a functional beverage or food additive.

[0041] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing cereal food therapy peptides by three-step enzymatic hydrolysis and products thereof, characterized in that: It includes six core steps: raw material processing and pulping, starch hydrolysis, simultaneous debittering with protease and flavor enzymes, saccharification hydrolysis, enzyme inactivation under normal pressure, and refining. The raw material processing and pulping involves color sorting, impurity removal, crushing, and irradiation of grains, followed by adding water and stirring to obtain a grain extract; the starch enzymatic hydrolysis involves adjusting the temperature and pH, then adding amylase to degrade starch into dextrins and oligosaccharides to improve the fluidity of the system. The simultaneous debittering by proteolysis and flavor enzymes involves simultaneously adding protease and flavor enzymes to degrade the protein into small molecule therapeutic peptides and remove the hydrophobic ends to achieve debittering at the source. The saccharification and enzymatic hydrolysis involves adding saccharifying enzymes to convert residual dextrins and oligosaccharides into reducing sugars to enhance sweetness and palatability; the atmospheric pressure enzyme inactivation involves gently terminating the reaction at 100°C, atmospheric pressure, and 0 MPa gauge pressure for 10–30 minutes. The refining process involves filtration, simultaneous separation of liquid and residue, homogenization, concentration, or drying to obtain therapeutic peptide products. The method employs a three-step synergistic enzymatic hydrolysis process with a cycle of 6 hours, which is 40% more efficient than the traditional 8–12 hour process. The resulting product has a molecular weight mainly below 3000 Da, a peptide yield increase of 15%–25%, and a debittering rate of >60%.

2. A process for the preparation of cereal dietetic peptides by three-step enzymatic hydrolysis according to claim 1, characterized in that: The grain raw material is any one of corn, oats, and millet, or a compound grain composed of oats and corn in a mass ratio of 1:1; the grain particle size after pulverization is 60 mesh or 80 mesh. In the raw material processing and pulping steps, the material-to-liquid ratio is 1:8, 1:9, or 1:10, and the added water is purified water. After stirring, a uniform and stable grain extract is formed. Irradiation treatment can kill microorganisms on the surface of the raw materials and reduce the content of anti-nutritional factors in the raw materials, thereby improving the efficiency of subsequent enzymatic hydrolysis and the hygiene and safety of the products.

3. The method for preparing cereal therapeutic peptides via three-step enzymatic hydrolysis according to claim 1, and the product thereof, characterized in that: In the starch enzymatic hydrolysis step, the hydrolysis temperature is 85℃ or 90℃, and the pH is adjusted to 5.5 or 6.

0. The added amylase is α-amylase or thermostable amylase, and the amount added is 0.5‰ or 0.6‰ of the dry weight of the raw material; The enzymatic hydrolysis time is 60 or 70 minutes, which fully degrades starch into dextrin and oligosaccharides, reduces system viscosity, improves system fluidity, and provides more space for proteases and flavor enzymes to function, achieving synergistic and efficient degradation of starch and protein.

4. The method for preparing cereal therapeutic peptides via three-step enzymatic hydrolysis according to claim 1, and the product thereof, characterized in that: In the step of simultaneous debittering with protease hydrolysis and flavor enzymes, the hydrolysis temperature is 53°C or 55°C, and the pH is adjusted to 6.5 or 7.

0. The protease is a neutral or alkaline protease, and the amount added is 0.1‰ or 0.3‰ of the dry weight of the raw material; The amount of flavor enzyme added is 0.3‰ or 0.4‰ of the dry weight of the raw materials; The simultaneous enzymatic hydrolysis time is 2 or 3 hours, which simultaneously completes the directional degradation of protein macromolecules into small molecule therapeutic peptides and the terminal removal of hydrophobic bitter peptides, blocking the production of bitterness from the source and achieving a stable debittering effect without bitterness.

5. The method for preparing cereal therapeutic peptides via three-step enzymatic hydrolysis according to claim 1, and the product thereof, characterized in that: In the saccharification and enzymatic hydrolysis step, the enzymatic hydrolysis temperature is kept consistent with the proteolytic hydrolysis temperature at 53°C or 55°C. The amount of saccharifying enzyme added is 0.1‰ or 0.3‰ of the dry weight of the raw materials; the enzymatic hydrolysis time is 1.5 hours or 2 hours. It completely converts the dextrin and oligosaccharides remaining after starch enzymatic hydrolysis into reducing sugars such as glucose. It can achieve a natural sweet taste without the need to add sucrose, sweeteners or other exogenous ingredients, thereby improving the palatability and food safety of the product.

6. The method for preparing cereal therapeutic peptides via three-step enzymatic hydrolysis according to claim 1, and the product thereof, characterized in that: The enzyme inactivation step under normal pressure is strictly controlled at a temperature of 100℃, a pressure of normal pressure and a gauge pressure of 0MPa, and an inactivation time of 15 minutes or 20 minutes. This gentle enzyme inactivation method avoids Maillard browning of materials, loss of heat-sensitive nutrients and reduction of bioactivity of therapeutic peptides caused by high temperature and high pressure, and fully preserves the inherent nutrition and small molecule peptide functional activity of the grain raw materials.

7. The method for preparing cereal therapeutic peptides via three-step enzymatic hydrolysis according to claim 1, and the product thereof, characterized in that: In the refining step, the liquid and slag are separated simultaneously using a 140-mesh filter to effectively remove raw material fibers and insoluble residues. After separation, high-pressure homogenization is performed to improve product uniformity and stability. Depending on the product form requirements, homogenization directly yields cereal-based dietary peptide liquid, or vacuum concentration and spray drying yields cereal-based dietary peptide powder. The separation, homogenization, concentration, and drying processes are all gentle physical treatments that do not damage the structure and bioactivity of small molecule peptides.

8. The method for preparing cereal therapeutic peptides via three-step enzymatic hydrolysis according to claim 1, and the product thereof, characterized in that: The three-step synergistic enzymatic hydrolysis involves starch hydrolysis, proteolysis, flavor debittering, and saccharification hydrolysis proceeding sequentially without interruption, repeated temperature control, or material transfer. Starch degradation and protein degradation proceed simultaneously, addressing industry technical deficiencies such as incomplete degradation by single or dual enzymatic hydrolysis, low substrate utilization, and low yield of small molecule peptides.

9. A method for preparing cereal therapeutic peptides via three-step enzymatic hydrolysis according to any one of claims 1–8, and the product thereof, characterized in that: The product is available in liquid or powder form, and the raw materials are single grains or compound grains. The molecular weight of the product is mainly distributed below 3000 Da, with a high content of small molecule peptides, a debittering rate of >60%, a sweet taste without bitterness, and good palatability. It has dietary therapy functions such as easy absorption, anti-oxidation, immune regulation, blood pressure reduction, and anti-fatigue. The nutrients and active ingredients are completely preserved, and it can be eaten directly or used as a raw material for functional foods.

10. The method for preparing cereal therapeutic peptides via three-step enzymatic hydrolysis according to claim 9, and the product thereof, characterized in that: The product is corn dietary peptide liquid, oat-corn compound dietary peptide powder, or millet dietary peptide liquid. Corn-based therapeutic peptide liquid uses corn as a single ingredient, oat-corn compound therapeutic peptide powder uses oat and corn in a 1:1 ratio as raw materials, and millet-based therapeutic peptide liquid uses millet as a single ingredient. The product manufacturing process operates entirely under normal pressure, uses universal equipment, has low energy consumption, high safety, and stable and controllable parameters, making it suitable for large-scale continuous industrial production.