Preparation method and application of low-GI germinated oat meal

Abstract

The invention belongs to the technical field of food processing, and particularly relates to a preparation method and application of low-GI germinated oat meal. The preparation method of the low-GI germinated oat rice comprises the following steps: (1) germination treatment and pulse spraying; (2) enzyme treatment; and (3) pressurizing, cooking and standing for retrogradation. Through the multi-step process of germination, pulse spraying, compound enzyme treatment, pressurized cooking, low-temperature retrogradation and the like, the taste of the oat meal is improved, and the nutritional ingredients are enriched.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, specifically relating to a method for preparing low-GI sprouted oat rice and its application. Background Technology

[0002] With the increasing popularity of healthy eating concepts, the demand for low glycemic index (GI) foods is growing, especially among diabetics, obese individuals, and those concerned about weight management. Low GI foods help slow the release of glucose, preventing a rapid rise in blood sugar, thus aiding in diabetes control, weight loss, and improved cardiovascular health. Oats, a grain rich in dietary fiber, minerals, amino acids, and other nutrients, are an ideal choice due to their low GI properties. However, while traditional oatmeal has a low GI and good nutritional value, it still has some shortcomings in terms of taste, palatability, flavor, and the release of nutrients.

[0003] Traditional oatmeal has a relatively coarse texture, which often hinders its widespread adoption, especially for consumers who regularly consume oats as a staple food. While modern food processing technology has made some efforts to improve the texture, oatmeal still struggles to achieve a softer and more palatable result, particularly for groups with specific nutritional needs, such as the elderly, infants, and patients.

[0004] Secondly, while traditional oat processing methods can retain a significant amount of dietary fiber and other nutrients, the relatively rigid outer cell walls of oats result in lower bioavailability of some nutrients (such as amino acids and minerals). To improve its nutritional value, additional processing methods are often required to enhance the release of these components, but these methods frequently conflict with improving taste. Therefore, maintaining the GI value and rich nutritional content of oatmeal while simultaneously improving its texture and flavor has become a pressing technical challenge in the food processing industry.

[0005] Relevant patent documents retrieved: For example, Chinese patent CN118303578A, published on July 9, 2024, provides a method for regulating the GI value of oat flakes through ultrasonic-assisted solid-state enzymatic hydrolysis, relating to the food industry. The method involves sequentially subjecting naked oat grains to needle-type cell wall breaking / light grinding, ultrasonic-assisted primary enzymatic hydrolysis, ultrasonic-assisted alkaline treatment to inhibit enzymatic hydrolysis, pelleting and grading, secondary enzymatic hydrolysis, tableting, and low-temperature drying to obtain finished oat flakes. By controlling the exposure degree of starch in the naked oat grains and combining two ultrasonic-assisted enzymatic hydrolysis processes, the method achieves partial debranching of oat starch in the naked oat grains, effectively increasing the resistant starch content in the oat flakes. This method not only improves the extraction rate of oat β-glucan in the finished product but also directly produces oat flakes with different GI values.

[0006] Relevant non-patent literature retrieved: This master's thesis from Lanzhou University of Technology, titled "A Study on the Nutritional Characteristics and Glycemic Index of Barley and Oats," volume number 2024.001165, investigates the nutritional chemical and physical properties of barley and oats, as well as their digestibility and absorption characteristics in vitro and in vivo, and their glycemic index. The study demonstrates that barley and oats are characterized by slow digestion and absorption and a low glycemic index. This research provides a scientific basis for the development and utilization of traditional grain food resources and for enriching the diets of patients with chronic metabolic diseases.

[0007] The prior art represented by the aforementioned documents has at least the following unresolved technical problems or defects: The inventions described above still need improvement in terms of taste, palatability, flavor, and release of nutrients.

[0008] In solving the above problems or overcoming the above defects, the present invention encountered the following difficulties and obstacles: 1. Excessive temperature, pH, and time in enzymatic hydrolysis may cause excessive softening of the tissue. This invention improves the softness and glutinousness without causing gelatinization and collapse by limiting the enzymatic hydrolysis conditions (pH / temperature / time / total enzyme activity) and setting an enzyme inactivation step.

[0009] 2. Temperature, humidity and water supply during the germination stage can affect uniformity and bring microbial risks; this invention uses pulse spraying and controls temperature, humidity and time window to make germination more uniform and reduce the probability of abnormal fermentation / mold.

[0010] 3. Differences in enzyme activity between different manufacturers / batches can lead to fluctuations in the degree of enzymatic hydrolysis; this invention uses total enzyme activity (U / g) as the basis for enzyme addition measurement, and the dosage can be calculated based on the nominal / actual enzyme activity to obtain equivalent enzyme activity.

[0011] 4. The amount of water added and the method of water replenishment will affect the nutrient dissolution and texture; the present invention adopts a segmented water replenishment control system to control the water content, so as to make the cooking uniform and take into account both taste and nutrient retention. Summary of the Invention

[0012] The purpose of this invention is to provide a method for preparing low-GI sprouted oat rice and its application, as well as related technologies, to solve the technical problems of poor taste and flavor, low nutritional content, etc. of existing oat rice, or a combination thereof.

[0013] Terminology Explanation: Unless otherwise defined, all technical terms in this document have the same meanings as commonly understood by one of ordinary skill in the art to which the subject matter of the claims pertains. Unless otherwise stated, all patents, patent inventions, and publications cited in this document are incorporated herein by reference in their entirety. If multiple definitions exist for terms in this document, the definitions in this chapter shall prevail.

[0014] It should be understood that the above brief description and the following detailed description are exemplary and for illustrative purposes only, and do not limit the subject matter of the invention in any way. In this invention, the singular is used in conjunction with the plural unless otherwise specifically stated. It should also be noted that, unless otherwise stated, the use of “or” or “or” means “and / or”. Furthermore, the use of the term “comprising” and other forms such as “including,” “containing,” and “contains” are not limiting.

[0015] The definition of the standard chemical term can be found in the reference "Functional Foods", China Agricultural University Press, 2024.

[0016] Unless specifically defined herein, the use of all commercially available products herein employs standard techniques. For example, it may be carried out using the manufacturer's instructions for use with the kit, or in accordance with methods known in the art or the description of this invention. The techniques and methods described herein can generally be implemented according to conventional methods well known in the art, based on the descriptions in the various summary and more specific documents cited and discussed in this specification.

[0017] The term "steaming" refers to a cooking method that uses the heat of steam to heat or cook food thoroughly.

[0018] The term "low GI" refers to foods with a low glycemic index, meaning they cause smaller fluctuations in blood sugar levels after consumption. These foods are typically digested and absorbed more slowly, providing a longer-lasting feeling of fullness. They are suitable for people who need to stabilize their blood sugar or control their weight, while also reducing the risk of metabolic diseases.

[0019] The term "retrogradation" refers to the process in food processing where gelatinized starch molecules rearrange themselves and form an ordered structure through hydrogen bonding under low-temperature conditions.

[0020] In a first aspect, the present invention provides a method for preparing low-GI sprouted oat rice, comprising the following steps: (1) Germination treatment and pulse spraying: oat seeds were subjected to germination treatment. During the germination process, pulse spraying was used to obtain germinated oats. (2) Enzyme treatment: Germinated oats are treated with compound enzymes and then the enzymes are inactivated to obtain treated oats; (3) Pressure cooking: The processed oats are pressure cooked; after cooking, they are left to stand to reflux. The complex enzyme mentioned in step (2) includes cellulase, hemicellulase and pectinase, with a mass ratio of 1-3:1:1.

[0021] Preferably, the mass ratio of cellulase, hemicellulase and pectinase is 2:1:1.

[0022] Preferably, the germination treatment in step (1) is performed at a temperature of 20-30℃, a humidity of 70-90%, and a time of 24-72h to promote the release of nutrients in oats. Other specific values ​​within the above range can be selected to achieve the technical effect of the present invention. For example, the temperature may include, but is not limited to, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, and 30℃; the humidity may include, but is not limited to, 70%, 75%, 80%, 85%, and 90%; and the time may include, but is not limited to, 24h, 48h, and 72h.

[0023] More preferably, the germination treatment in step (1) is performed at a temperature of 25°C, a humidity of 85%, and a time of 48 hours.

[0024] Preferably, the specific operation of the pulse spraying treatment in step (1) is as follows: spray water on the germinated oats every 1-3 hours, with the amount of water being 1.5-2.5 times the dry weight of the oats, to ensure uniform water penetration and promote uniform germination; other specific point values ​​within the above range can be selected, all of which can achieve the technical effect of the present invention, such as the amount of water including but not limited to 1.5 times, 2.0 times, and 2.5 times the dry weight of the oats, and the spraying frequency including but not limited to once every 1 hour, once every 2 hours, and once every 3 hours.

[0025] More preferably, the specific operation of the pulse spraying treatment in step (1) is as follows: spray water on the sprouted oats every 2 hours, and the amount of water is twice the dry weight of the oats.

[0026] Preferably, the total enzyme activity of the complex enzyme in step (2) is 100-500 U / g, the temperature of the complex enzyme treatment is 45-55℃, the pH is 4.8-5.2, and the time is 20-60 min; other specific values ​​within the above range can be selected, and all can achieve the technical effect of the present invention. For example, the temperature of the complex enzyme treatment includes but is not limited to 45℃, 46℃, 47℃, 48℃, 49℃, and 50℃; the pH includes but is not limited to 4.8, 4.9, 5.0, 5.1, and 5.2; and the time includes but is not limited to 20 min, 30 min, 40 min, 45 min, 50 min, and 60 min.

[0027] More preferably, the total enzyme activity of the complex enzyme in step (2) is 300 U / g, and the temperature of the complex enzyme treatment is 50°C, the pH is 5.0, and the time is 45 min.

[0028] Preferably, the enzyme inactivation temperature in step (2) is 90-100℃ and the time is 1-5 min, and microwave inactivation is used; other specific values ​​within the above range can be selected, and all can achieve the technical effect of the present invention, such as temperatures including but not limited to 90℃, 91℃, 92℃, 93℃, 94℃, 95℃, 96℃, 97℃, 98℃, 99℃, 100℃, and times including but not limited to 1 min, 2 min, 3 min, 4 min, 5 min.

[0029] More preferably, the enzyme inactivation temperature in step (2) is 95°C and the time is 3 min.

[0030] Preferably, the pressure cooking temperature in step (3) is 110-121℃, the cooking time is 15-30 min, the pressure is 0.05-0.15 MPa, and the amount of water added during cooking is 1.8-2.5 times the volume of the treated oats. The water is added in stages, with 60-80% of the total water added initially and the remaining amount added after cooking for 10-15 min. Other specific values ​​within the above range can be selected to achieve the technical effect of the present invention. For example, the cooking time includes, but is not limited to, 15 min, 20 min, 25 min, and 30 min; the pressure includes, but is not limited to, 0.05 MPa, 0.10 MPa, and 0.15 MPa; and the amount of water added during cooking includes, but is not limited to, 1.8 times, 2.0 times, 2.2 times, and 2.5 times the volume of the treated oats.

[0031] More preferably, the pressure cooking temperature in step (3) is 115°C, the cooking time is 20 min, the pressure is 0.1 MPa, the amount of water added during cooking is 2.2 times the volume of the treated oats, and the water is controlled by adding water in stages. 70% of the total water is added for the first time, and 30% is added after cooking for 10 min.

[0032] Preferably, the temperature for static regrowth in step (3) is 4-6℃ and the time is 12-24h. Other specific values ​​within the above range can be selected to achieve the technical effect of the present invention. For example, the time includes but is not limited to 12h, 15h, 18h, and 24h, and the temperature for static regrowth includes but is not limited to 4℃, 5℃, and 6℃.

[0033] More preferably, the temperature for static regeneration in step (3) is 4°C and the time is 24h.

[0034] Secondly, the present invention also provides low-GI sprouted oat rice prepared by the above-described preparation method.

[0035] Thirdly, the present invention also provides the application of the low-GI sprouted oat rice prepared by the above preparation method in the preparation of low-GI foods.

[0036] Specifically, the food items mentioned are breakfast foods, snack products, desserts, or yogurt companions.

[0037] In this invention, Examples 1-3 at least support the protection scope of the technical feature "the complex enzyme includes cellulase, hemicellulase and pectinase, and the mass ratio of the three is 1-3:1:1".

[0038] Regarding the claim 1: The technical feature "complex enzyme comprising cellulase, hemicellulase, and pectinase in a mass ratio of 1-3:1:1" is derived from the aforementioned explanation and / or the corresponding technical features in Examples 1-3, such as a mass ratio of 1:1:1, 2:1:1, or 3:1:1, through the common feature "a mass ratio of 1-3:1:1 for cellulase, hemicellulase, and pectinase." Therefore, those skilled in the art can reasonably infer that any mass ratio of 1-3:1:1 for cellulase, hemicellulase, and pectinase should fall within the scope of protection of claim 1. For example, replacing 2:1:1 with 1.5:1:1 while keeping other technical features unchanged would still fall within the scope of protection of the technical feature "complex enzyme comprising cellulase, hemicellulase, and pectinase in a mass ratio of 1-3:1:1" of this invention.

[0039] The present invention has the following effects: This invention improves the taste and nutritional content of oat rice through a multi-step process including germination, pulse spraying, compound enzyme treatment, pressure cooking, and low-temperature retrogradation. The combination of germination and pulse spraying ensures uniform germination of the oats, improving texture and flavor. Compound enzyme treatment effectively degrades the oat cell walls, increasing softness and palatability. Pressure cooking retains and generates more nutrients, further enhancing the texture of the oat rice. Low-temperature retrogradation increases the content of resistant starch, maintaining its low-GI characteristics, making it suitable for people with low-GI dietary needs.

[0040] Furthermore, based on the present invention: Based on the comparison of Examples 1-3 and Comparative Examples 1-3, the present invention employs a combination of techniques such as germination treatment, compound enzyme treatment, and low-temperature retrogradation treatment to improve the taste and nutritional components of oat rice, increase the content of resistant starch, and maintain its low-GI characteristics. The combined technical effect is superior to the sum of the effects of each individual technique. Attached Figure Description

[0041] Figure 1 Flowchart for the preparation of low-GI sprouted oat rice products; Figure 2The bar chart shows the resistant starch content (different letters indicate statistically significant differences). Detailed Implementation

[0042] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention. Those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and these should also fall within the scope of protection claimed by the present invention. The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all instruments, devices, equipment, reagents, products, etc., used in the embodiments of the present invention are obtained through conventional commercial means.

[0043] The manufacturers of the raw materials used in this invention are shown in Table 1 below: Table 1

[0044] The technical effects of this invention can also be achieved using raw materials from other manufacturers.

[0045] Example 1: A method for preparing low-GI sprouted oat rice The specific steps are as follows: (1) Germination and pulse spraying treatment: After washing the whole oat grains, soak them at 25℃ for 12 h, drain them and place them in a constant temperature room. The germination temperature is 25℃ and the relative humidity is 85% for 48 h. During the germination process, water is replenished by pulse spraying. The spraying frequency is once every 2 h and the spraying time is 30 s. The total spraying water volume is twice the dry weight of the oats.

[0046] (2) Compound enzyme treatment and microwave enzyme inactivation: After germination, add compound cellulase preparation (mass ratio of cellulase: hemicellulase: pectinase = 2:1:1, total enzyme activity is 300 U / g) to the oats on a dry basis and react for 45 min at 50℃ and pH 5.0. After the reaction is completed, microwave enzyme inactivation is used with a power of 700 W, the core temperature of the material reaches 95℃ and is maintained for 3 min.

[0047] (3) Pressure cooking and low-temperature retrogradation: Add the enzyme-treated oats and water to the pressure cooker at a ratio of 1:2.2 (volume ratio). Cook at 115℃, 0.10 MPa, and 20 min.

[0048] Use a segmented water replenishment method: initially add 70% of the total water volume; after steaming for 10 minutes, add the remaining 30% of the water volume, which is hot water heated to 90-100℃; Low-temperature retrogradation: After steaming or cooking, quickly cool down the cooked oat rice and let it stand at 4°C for 24 hours.

[0049] Example 2: A method for preparing low-GI sprouted oat rice The specific steps are as follows: (1) Germination and pulse spraying treatment: After washing the whole oat grains, soak them at 25℃ for 12 hours, drain them and place them in a constant temperature room. The germination temperature is 20℃ and the relative humidity is 70%. Germination lasts for 72 hours. During the germination process, water is replenished by pulse spraying. The spraying frequency is once every 3 hours and the spraying time is 30 seconds. The total amount of water sprayed is 1.5 times the dry weight of the oats. (2) Compound enzyme treatment and microwave enzyme inactivation: After germination, compound cellulase preparation (mass ratio of cellulase: hemicellulase: pectinase = 1:1:1, total enzyme activity of 500 U / g) was added to the oats on a dry basis and reacted at 45℃ and pH 4.8 for 20 min. After the reaction was completed, microwave enzyme inactivation was used with a power of 700 W, and the core temperature of the material reached 95℃ and was maintained for 3 min. (3) Pressure cooking and low-temperature retrogradation: Add the enzyme-treated oats and water to the pressure cooker at a ratio of 1:1.8 (by volume). Cook at 110°C, 0.05 MPa, and 20 min.

[0050] Use a segmented water replenishment method: initially add 60% of the total water volume; after steaming for 10 minutes, add the remaining 40% of the water volume, which is hot water heated to 90-100℃; Low-temperature retrogradation: After steaming or cooking, quickly cool down the cooked oat rice and let it stand at 4°C for 24 hours.

[0051] Example 3: A method for preparing low-GI sprouted oat rice The specific steps are as follows: (1) Germination and pulse spraying treatment: After washing the whole oat grains, soak them at 25℃ for 12 h, drain them and place them in a constant temperature room. The germination temperature is 30℃ and the relative humidity is 90%, and the germination time is 24 h. During the germination process, water is replenished by pulse spraying. The spraying frequency is once every 1 h and the spraying time is 30 s. The total spraying water volume is 2.5 times the dry weight of the oats. (2) Compound enzyme treatment and microwave enzyme inactivation: After germination, compound cellulase preparation (mass ratio of cellulase: hemicellulase: pectinase = 3:1:1, total enzyme activity of 100 U / g) was added to the oats on a dry basis and reacted at 55℃ and pH 5.2 for 60 min. After the reaction was completed, the enzyme was inactivated by microwave at a power of 700 W, and the temperature of the material center reached 100℃ and was maintained for 5 min. (3) Pressure cooking and low-temperature retrogradation: Add the enzyme-treated oats and water to the pressure cooker at a ratio of 1:2.5 (volume ratio). Cook at 121℃, 0.15MPa, and 20 min.

[0052] Use a segmented water replenishment method: initially add 80% of the total water volume; after steaming for 10 minutes, add the remaining 20% ​​of the water volume, which is hot water heated to 90-100℃; Low-temperature retrogradation: After steaming or cooking, quickly cool down the cooked oat rice and let it stand at 4°C for 24 hours.

[0053] Comparative Example 1 The difference from the example is that no germination process is performed, as follows: (1) Oat pre-soaking: After washing whole oat grains, soak them at 25°C for 12 hours, drain and dry at room temperature; (2) Compound enzyme treatment and microwave enzyme inactivation: After germination, compound cellulase preparation (mass ratio of cellulase: hemicellulase: pectinase = 2:1:1, total enzyme activity of 300 U / g) was added to the oats on a dry basis and reacted at 50℃ and pH 5.0 for 45 min. After the reaction was completed, microwave enzyme inactivation was performed at a power of 700 W, and the core temperature of the material reached 95℃ and was maintained for 3 min. (3) Pressure cooking and segmented water replenishment: Add the enzyme-treated oats and water to the pressure cooker at a ratio of 1:2.2 (volume ratio) and cook at a temperature of 115℃, a pressure of 0.10 MPa and a time of 20 min.

[0054] The water is added in stages: 70% of the total water is added initially; after steaming for 10 minutes, the remaining 30% of the water is added, which is hot water heated to 90–100℃. Low-temperature retrogradation: After steaming or cooking, quickly cool down the cooked oat rice and let it stand at 4°C for 24 hours.

[0055] Comparative Example 2 The difference from Example 1 is that an equal amount of cellulase is replaced with an equal amount of hemicellulase, i.e., hemicellulase:pectinase = 3:1 (mass ratio). Everything else is the same as in Example 1.

[0056] Comparative Example 3 The difference from Example 1 is that no low-temperature retrogradation treatment was performed. The specific steps are as follows: (1) Germination and pulse spraying treatment: After washing the whole oat grains, soak them at 25℃ for 12 h, drain them and place them in a constant temperature room. The germination temperature is 25℃ and the relative humidity is 85%, and the germination time is 48 h. During the germination process, water is replenished by pulse spraying. The spraying frequency is once every 2 h and the spraying time is 30 s. The total spraying water volume is twice the dry weight of the oats. (2) Compound enzyme treatment and microwave enzyme inactivation: After germination, compound cellulase preparation (mass ratio of cellulase: hemicellulase: pectinase = 2:1:1, total enzyme activity of 300 U / g) was added to the oats on a dry basis and reacted at 50℃ and pH 5.0 for 45 min. After the reaction was completed, microwave enzyme inactivation was performed at a power of 700 W, and the core temperature of the material reached 95℃ and was maintained for 3 min. (3) Pressure cooking and segmented water replenishment: Add the enzyme-treated oats and water to the pressure cooker at a ratio of 1:2.2 (volume ratio) and cook at a temperature of 115℃, a pressure of 0.10 MPa and a time of 20 min.

[0057] The water is added in stages: 70% of the total water is added initially; after steaming for 10 minutes, the remaining 30% of the water is added, which is hot water heated to 90-100℃.

[0058] Test case (1) Determination of resistant starch content The resistant starch content was determined by enzymatic method: The samples prepared in each example and comparative example were pulverized and dried to constant weight. A mixed enzyme solution of heat-resistant pancreatic amylase and glucoamylase was added at 37°C for 120 min to hydrolyze the samples to remove digestible starch. The precipitate was then washed with 80% ethanol and centrifuged. The unhydrolyzed portion was retained, dissolved in potassium hydroxide solution, and the pH was adjusted to about 4.5. Glucoamylase was then added and reacted at 50-60°C until it was completely converted to glucose. The glucose content was determined at 510 nm using the glucose oxidase-peroxidase colorimetric method, and the resistant starch content (% dry basis) was calculated as glucose × 0.9.

[0059] (2) Determination of amino acid content This method is used to determine the amino acid content in samples. First, the samples prepared in each example and comparative example are ground and mixed thoroughly. 0.10 g of the sample is accurately weighed and placed in a 15 mL transparent centrifuge tube. 4.0 mL of 6 mol / L HCl is added, and the mixture is thoroughly shaken in a shaker for 5 min. The centrifuge tube is then placed in an oven at 105℃ for hydrolysis for 24 h. After hydrolysis, the sample is removed and immediately cooled to room temperature with cold water to observe whether hydrochloric acid needs to be added. Next, 4.0 mL of 6 mol / L NaOH solution is added, and the mixture is thoroughly shaken in a shaker for 5 min. After adjusting to neutral, the volume is brought to 10 mL with water. The mixture is then centrifuged at 4000 r / min for 10 min, and 0.50 mL of the supernatant is used for derivatization. In the derivatization reaction, 0.10 mL of hydrolysate was added to a 15 mL brown centrifuge tube, followed by 0.50 mL of sodium bicarbonate buffer solution (pH 9.0) and 0.50 mL of DNFB. The mixture was incubated in a water bath at 60 ± 0.5 °C in the dark for 60 min. After the reaction, the sample was removed and cooled to room temperature with cold water. 3.5 mL of phosphate buffer solution (pH 7.0) was added, and the mixture was thoroughly mixed and incubated in the dark at room temperature for 15 min. Subsequently, the supernatant was filtered through a 0.22 μm filter membrane and analyzed by liquid chromatography.

[0060] The liquid chromatography analysis conditions were as follows: VWD detector, C18 column (250 × 4.6 mm, 0.5 μm), column temperature (38℃), wavelength (360 nm), flow rate (1.0 mL / min), injection volume (20 μL), mobile phase A (acetonitrile:methanol = 90:10), and mobile phase B (0.02 mol / L sodium dihydrogen phosphate + disodium hydrogen phosphate).

[0061] (3) Determination of mineral content The samples (0.1000 g - 0.7000 g) prepared in each example and comparative example were accurately weighed and placed in a polytetrachloroethylene microwave tube. 10 mL of analytical grade concentrated nitric acid was added, and the mixture was thoroughly mixed and shaken for 1 min. After initial mixing, the microwave tube was heated to 120°C for pre-digestion for 20 min, until a small amount of yellow fumes appeared in the digestion tube. Next, 5.0 mL of concentrated nitric acid was added, the cap was tightened, and digestion was performed in a microwave digester according to the set temperature program. After digestion, the temperature was allowed to drop to room temperature before the acid removal step was performed, heating at 180°C for 30 min until approximately 1 mL of liquid remained and the digestion solution was clear and transparent. Finally, the digestion solution was diluted to 50 mL with ultrapure water, mixed thoroughly, and filtered through a 0.22 μm filter membrane to remove impurities. After dilution as needed, inductively coupled plasma mass spectrometry (ICP-MS) was performed to analyze the metal ion content.

[0062] (4) Texture analysis After conditioning, the samples prepared in each embodiment and comparative example were equilibrated at room temperature (approximately 25°C) and subjected to dual compression mode (TPA) testing using a texture analyzer. The test parameters were set as follows: P / 36 cylindrical indenter probe type, compression to 50% of the original sample height, compression speed of 1.0 mm / s, and a 5-s interval between two compressions. The instrument automatically recorded texture parameters such as hardness, elasticity, cohesiveness, chewiness, and resilience. Each sample underwent at least six parallel measurements, and the average value was used for analysis.

[0063] Table 2 Amino Acid Content Table

[0064] Table 3 Mineral Content Table

[0065] Table 4. Changes in texture

[0066] Results Analysis The low-GI germinated oat rice preparation process proposed in this invention significantly improves the nutritional quality and textural properties of oat rice through a synergistic approach involving germination, enzymatic hydrolysis, pressure cooking, and low-temperature retrogradation. Figure 2 ).

[0067] like Figure 2 The results show that, compared with the comparative example, the resistant starch content of the embodiment is significantly increased, indicating that germination + compound enzymatic hydrolysis + pressure cooking + low temperature retrogradation has a significant promoting effect on the formation of resistant starch, verifying that the process can effectively improve the low GI characteristics of the product.

[0068] The amino acid analysis results (Table 2) show that the contents of most amino acids (aspartic acid, glutamic acid, serine, arginine, etc.) in Examples 1 and 2 are higher than those in the comparative sample, with glutamic acid showing a particularly significant increase (16.86 g / 100g in Example 1 and 11.79 g / 100g in Comparative Example 1). This suggests that germination and enzymatic hydrolysis can promote protein degradation and the accumulation of free amino acids, thereby enhancing flavor and nutritional value.

[0069] Mineral analysis (Table 3) showed that the contents of key minerals such as Na, K, Ca, and P in the sample of the example were higher than those in the control. In particular, the phosphorus content in Example 1 reached 4981.23 μg / g, which was significantly higher than the 3861.6 μg / g in Comparative Example 1. This indicates that germination metabolism may promote phytic acid degradation and improve mineral availability.

[0070] The texture test results (Table 4) show that the hardness of the samples in Example 1 and Example 2 is significantly lower than that of the comparative example (50.11 gf for Example 1 and 66.72 gf for Comparative Example 1). The chewiness and cohesiveness indices also tend to be soft and easy to chew, proving that the compound enzymatic hydrolysis and germination process improves the cell wall structure and starch-protein complex, making the finished product softer and more delicate, suitable for long-term staple food consumption.

[0071] In summary, the low-GI sprouted oat rice prepared by this invention exhibits excellent performance in terms of resistant starch content, amino acid nutrition enhancement, mineral release, and texture improvement, and has significant health advantages and nutritional value compared to the oat rice prepared in Comparative Examples 1-3.

[0072] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing low-GI sprouted oat rice, characterized in that, Includes the following steps: (1) Germination treatment and pulse spraying: oat seeds were subjected to germination treatment. During the germination process, pulse spraying was used to obtain germinated oats. (2) Enzyme treatment: Germinated oats are treated with compound enzymes and then the enzymes are inactivated to obtain treated oats; (3) Pressure cooking: The processed oats are pressure cooked; after cooking, they are left to stand to reflux. The complex enzyme mentioned in step (2) includes cellulase, hemicellulase and pectinase, with a mass ratio of 1-3:1:

1.

2. The preparation method according to claim 1, characterized in that, The mass ratio of cellulase, hemicellulase and pectinase is 2:1:

1.

3. The preparation method according to claim 1, characterized in that, The germination treatment in step (1) is carried out at a temperature of 20-30℃, a humidity of 70-90%, and a time of 24-72h.

4. The preparation method according to claim 1, characterized in that, The specific operation of the pulse spraying treatment in step (1) is as follows: spray water on the germinated oats every 1-3 hours, with the amount of water being 1.5-2.5 times the dry weight of the oats.

5. The preparation method according to claim 1, characterized in that, The total enzyme activity of the complex enzyme in step (2) is 100-500 U / g, and the temperature of the complex enzyme treatment is 45-55℃, the pH is 4.8-5.2, and the time is 20-60 min.

6. The preparation method according to claim 1, characterized in that, The enzyme inactivation temperature in step (2) is 90-100℃, and the time is 1-5 min, using microwave inactivation.

7. The preparation method according to claim 1, characterized in that, The pressure cooking temperature in step (3) is 110-121℃, the cooking time is 15-30 min, the pressure is 0.05-0.15 MPa, and the amount of water added during cooking is 1.8-2.5 times the volume of the treated oats. The water is added in stages, with 60-80% of the total water added initially and the remaining amount added after cooking for 10-15 min.

8. The preparation method according to claim 1, characterized in that, The temperature for static regeneration in step (3) is 4-6℃, and the time is 12-24h.

9. Low-GI sprouted oat rice prepared by the preparation method according to any one of claims 1-8.

10. The use of the low-GI sprouted oat rice prepared by the method according to any one of claims 1-8 in the preparation of low-GI foods.

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