Oat composite extract as well as preparation method and application thereof

Abstract

The invention relates to the technical field of oat composite extracts, and particularly discloses an oat composite extract as well as a preparation method and application thereof. The invention discloses a preparation method of an oat composite extract. The preparation method comprises the following specific steps: preparing materials and mixing pulp, performing enzymolysis, filtering and concentrating, performing spray drying, crushing and sieving, and storing and transporting. The preparation method comprises the following steps: crushing oat flour, malt flour and corn flour, adding water and a stabilizer, and uniformly stirring to obtain primary pulp; the enzymolysis step comprises the following steps: adding an enzymolysis agent A into the primary pulp for enzymolysis, and performing high-temperature enzyme inactivation; cooling to room temperature, adding an enzymolysis agent B for enzymolysis, and inactivating enzyme at high temperature; cooling to obtain oat zymolyte; the enzymolysis agent A is formed by mixing beta-amylase and flavourzyme; the enzymolysis agent B is formed by mixing high-temperature-resistant alpha-amylase and neutral protease. The obtained oat composite extract is appropriate in saccharification degree, and the oat composite extract has high oxidation resistance and stability, so that the application range of the oat composite extract is widened.

Description

Technical Field

[0001] The present application relates to the technical field of oat composite extracts, and in particular to an oat composite extract and a preparation method and application thereof. Background Art

[0002] Oat compound extracts have attracted much attention due to their rich bioactive ingredients, including avenanthramides, flavonoids, and avenanthramides, which are directly or indirectly related to the neurotransmitter receptors, hormones, and dopamine secretion in the human brain. At present, oat compound extracts have certain application research in the fields of food, medicine, and cosmetics. In the field of food, oat compound extracts can be used as food additives to increase the nutritional value and functional properties of food due to their antioxidant and blood sugar and lipid regulation properties.

[0003] At present, there are many methods for extracting oat compound extracts from oats. The preparation process of oat compound extracts generally adopts bio-enzymatic hydrolysis technology for extraction. Amylase can be used to decompose the natural starch in oats into small molecular sugars and oligosaccharides soluble in water. Protease can be used to degrade the reducing sugar in oats into small molecular weight peptide chains and amino acids soluble in water, which are beneficial to human digestion and absorption.

[0004] However, the quality and effect of oat compound extracts are affected by the extraction method. Existing extraction methods may result in different contents and proportions of active ingredients in the extracts, and the reducing sugar content in the prepared oat compound extracts is low or too high, and the antioxidant activity is weak. In addition, some nutrients in the oat compound extracts may change during extraction, processing, storage or transportation, thus affecting their stability and effect.

[0005] Therefore, the extraction process needs to be further optimized to ensure the quality and stability of oat complex extracts. Summary of the invention

[0006] In order to solve the above technical problems, the present application provides an oat composite extract and a preparation method and application thereof.

[0007] In a first aspect, the present application provides a method for preparing an oat composite extract, which specifically comprises the following steps in sequence: batching and slurry preparation, enzymatic hydrolysis, filtration and concentration, spray drying, crushing and screening, storage and transportation; The specific steps of the ingredient slurry preparation are: 800-960 parts by weight of oatmeal powder, 20-140 parts by weight of malt powder, and 20-60 parts by weight of corn flour are crushed, 4-6 times the weight of water of the raw materials are added, and stirred evenly; then 5-10 parts by weight of a stabilizer are added, and stirred evenly to obtain an oatmeal composite slurry; The stabilizer is obtained by mixing phosphatidylserine, soybean isoflavones, and liquid algae oil in a weight ratio of 1-10:1-10:1-10; The specific steps of enzymolysis are: adding 0.04-0.12 parts by weight of enzymolysis agent A to the oat composite raw pulp, heating to 50-70°C, enzymolysis for 20-50 minutes, and high temperature inactivating enzyme activity; then cooling to room temperature, adding 0.002-0.008 parts by weight of enzymolysis agent B, heating to 60-75°C, enzymolysis for 20-50 minutes, and high temperature inactivating enzyme activity; cooling to obtain oat enzymolysis product; The enzymolysis agent A is composed of a mixture of β-amylase and flavor protease in a weight ratio of 1-3:0.2-0.8; The enzymolysis agent B is composed of a mixture of thermostable α-amylase and neutral protease in a weight ratio of 1-3:1-3.

[0008] In the preparation process of oat composite extract, the inventor found that using oat flour, malt flour and corn flour as raw materials, first using β-amylase and flavor protease mixed to form enzymolysis agent A to hydrolyze the raw materials once, and then using high temperature resistant α-amylase and neutral protease mixed as enzymolysis agent B for secondary enzymolysis can effectively improve the comprehensive performance of oat composite extract. In this process, the raw materials are firstly hydrolyzed by enzymolysis agent A, which is composed of β-amylase and flavor protease, mainly using β-amylase to decompose starch into maltose, while the flavor protease acts on the reducing sugar in the raw materials to release small peptides and amino acids with specific flavors, adding a unique flavor to the oat composite extract; then, the enzymolysis agent B composed of high temperature resistant α-amylase and neutral protease is used for secondary enzymolysis, the purpose of which is to further deeply decompose the remaining starch and reducing sugars and improve the nutritional value of the extract; while the neutral protease continues to degrade the reducing sugars to generate more small peptides and free amino acids that are easy to absorb. The oat composite extract prepared by the secondary enzymatic hydrolysis method has a more uniform molecular structure, which can significantly improve the nutritional value of the product, improve the flavor and taste, increase the product stability, and broaden its application range.

[0009] In addition, in the process of preparing oat composite extract by enzymolysis, adverse factors in the external environment (such as oxidants, light and high temperature) will affect the efficiency of enzymolysis and the stability of the final product. The inventors found that phosphatidylserine, soybean isoflavones and liquid algae oil were used as stabilizers, each with a unique effect, and the synergistic effect between them also provided stable support for the enzymolysis process and product preservation process. Phosphatidylserine can bind to enzyme molecules to play a protective role, preventing the enzyme from being inactivated or denatured during the reaction, thereby ensuring the continuation of the enzymolysis reaction; the specific structure of phosphatidylserine helps the substrate molecules to bind more closely to the enzyme and improve the efficiency of enzymolysis. Soybean isoflavones have strong antioxidant capacity, can remove free radicals generated during enzymolysis, and protect enzymes and raw materials from oxidative damage; at the same time, soybean isoflavones can gently regulate the activity of the enzyme to avoid the enzymolysis reaction being too intense or prematurely terminated. Liquid algae oil is rich in unsaturated fatty acids, which is conducive to maintaining the flexibility and activity of enzyme molecules. In summary, the combination of phosphatidylserine, soy isoflavones and liquid algae oil synergistically ensures the efficient and stable enzymatic hydrolysis process by enhancing enzyme stability, providing antioxidant protection, regulating enzyme activity and enhancing the stability of the reaction system.

[0010] More importantly, the phosphatidylserine in the stabilizer can combine with the active ingredients in the oat complex extract to form a protective lipid film, thereby slowing down the degradation rate of the active ingredients; by enhancing the interaction between the molecules of the oat complex extract, phosphatidylserine also helps to improve the stability of the entire system. Soy isoflavones have excellent antioxidant properties and can remove free radicals that cause the instability of the oat complex extract. This can not only extend the shelf life of the extract, but also help maintain its original nutritional value and biological activity; and synergize with other components in the oat complex extract (such as certain reducing sugars or polysaccharides) to form a more stable complex and jointly improve the stability of the entire system. The unsaturated fatty acids rich in liquid algae oil help maintain the stability of the fat-soluble components in the oat complex extract. These fatty acids can combine with fat-soluble active substances to prevent them from oxidation or polymerization during storage. Therefore, phosphatidylserine, soybean isoflavones and liquid algae oil, as stabilizers, work together on the oat complex extract in many aspects to significantly improve its stability; this is of great significance for protecting the unique efficacy of the oat complex extract, extending the shelf life of the product and improving the consumer experience.

[0011] Preferably, in the slurry preparation, the amount of each raw material component is: 840-920 parts by weight of oatmeal powder, 60-100 parts by weight of malt powder, and 30-50 parts by weight of corn flour.

[0012] Preferably, the stabilizer is obtained by mixing phosphatidylserine, soybean isoflavones and liquid algae oil in a weight ratio of 8-10:1-3:1-3.

[0013] Preferably, the specific steps of the enzymolysis are: adding 0.06-0.10 weight parts of enzymolysis agent A to the oat composite raw pulp, heating to 55-65°C, enzymolysis for 40-50 minutes, and high temperature inactivating the enzyme; then cooling to room temperature, adding 0.004-0.006 weight parts of enzymolysis agent B, heating to 65-75°C, enzymolysis for 20-30 minutes, and high temperature inactivating the enzyme; obtaining oat hydrolysate.

[0014] Preferably, the specific steps of the enzymolysis are: adding 0.06-0.10 weight parts of enzymolysis agent A to the oat composite raw pulp, adjusting the pH to 5.0-6.0, heating to 55-65°C, enzymolysis for 40-50 minutes, and high temperature inactivation of enzymes; then cooling to room temperature, adding 0.004-0.006 weight parts of enzymolysis agent B, adjusting the pH to 6.0-7.5, heating to 65-75°C, enzymolysis for 20-30 minutes, and high temperature inactivation of enzymes; obtaining oat hydrolysate.

[0015] Preferably, the enzymatic agent A is composed of a mixture of β-amylase and flavor protease in a weight ratio of 1.5-2.5:0.4-0.6.

[0016] Preferably, the enzymolysis agent B is composed of a mixture of thermostable α-amylase and neutral protease in a weight ratio of 2-3:1-2.

[0017] Preferably, the process parameters of the spray drying are: air inlet temperature is 145-165°C, air outlet temperature is 65-85°C, and the temperature in the tower is maintained at 75-90°C.

[0018] In a second aspect, the present application provides an oat composite extract prepared using the above-mentioned preparation method.

[0019] In a third aspect, the present application provides the application of the above-mentioned oat composite extract in food and skin care products.

[0020] In summary, the technical solution of this application has the following effects: The present application uses oat flour, malt flour and corn flour as raw materials, firstly uses a mixture of β-amylase and flavor protease to form an enzymatic agent A to perform a primary enzymatic hydrolysis on the raw materials, and then uses a mixture of high-temperature resistant α-amylase and neutral protease as an enzymatic agent B to perform a secondary enzymatic hydrolysis, and at the same time uses a mixture of phosphatidylserine, soy isoflavones and liquid algae oil as a stabilizer. The prepared oat composite extract has an appropriate degree of saccharification, and the oat composite extract has strong antioxidant properties and stability, thereby broadening the application range of the oat composite extract. DETAILED DESCRIPTION

[0021] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in the present application.

[0022] β-Amylase (Product No. 557) was sourced from Zhengzhou Wanbo Chemical Products Co., Ltd.; glucoamylase (Product No. FDY-3803), flavor protease (Product No. FDG-2202), thermostable α-amylase (Product No. FDY-2801), and neutral protease (Product No. FDG-2230) were sourced from Cangzhou Xiasheng Enzyme Biotechnology Co., Ltd.; phosphatidylserine (Product No. 223), soybean lecithin (Product No. 214), soybean isoflavones, and liquid algae oil (Product No. 217) were purchased from Qingdao Huazhiyuan Food Additive Co., Ltd.; the remaining raw materials were commercially available. Example

[0023] Examples 1-5 Examples 1-5 respectively provide an oat composite extract and a preparation method thereof.

[0024] The difference between the above embodiments is that the dosage of each component in the oat composite pulp is different, as shown in Table 1.

[0025] The preparation method of the oat composite extract in the above embodiment is: (1) Mixing ingredients: weigh oatmeal powder, malt powder, and corn powder according to the formula and grind them in a grinder to a particle size of ≤100 mesh; pour the ground raw materials into a mixing cylinder, add water 5 times the weight of the raw materials, and stir them evenly at a speed of 120 r / min; then add 8 g of stabilizer (mixed by phosphatidylserine, soybean isoflavones, and liquid algae oil in a weight ratio of 9:2:2), and stir them evenly at a speed of 120 r / min to obtain oatmeal composite slurry; (2) Enzymolysis: add 0.08 g of enzymolysis agent A (composed of a mixture of β-amylase and flavor protease in a weight ratio of 2:0.5) to the oat composite raw pulp, adjust the pH to 5.5, heat to 60°C, perform enzymolysis for 45 minutes, and heat to 95°C to inactivate the enzyme for 10 minutes; then cool to room temperature, add 0.005 g of enzymolysis agent B (composed of a mixture of thermostable α-amylase and neutral protease in a weight ratio of 2.5:1.5), adjust the pH to 7.0, heat to 70°C, perform enzymolysis for 25 minutes, and then heat to 95°C to inactivate the enzyme for 10 minutes; cool to obtain oat enzymolysis product; (3) Filtration and concentration: Filter the oat hydrolysate to remove the residue and collect the oat juice. At the same time, concentrate the collected oat juice in a multi-effect falling mode evaporator to obtain a high-concentration oat slurry, and then fill the high-concentration oat slurry into plastic barrels according to specifications; (4) Spray drying: During the spray drying process of high-concentration oat slurry, the inlet air temperature is 155°C, the outlet air temperature is 75°C, and the air supply and exhaust volumes are adjusted to maintain the temperature in the tower at 75-90°C.

[0026] (5) Crushing and screening: The dried powder needs to be finely screened to remove blocky connections and ensure that the powder mesh size is qualified.

[0027] (6) Storage and transportation: Store the oat compound extract powder in a ventilated, cool and dry place, away from fire sources. The oat compound extract powder should be loaded and unloaded with care during transportation.

[0028] Table 1 Amount of each component in the oat composite syrup in Examples 1-5 Embodiment 6-9 Examples 6-9 respectively provide an oat composite extract and a preparation method thereof.

[0029] The difference between the above embodiment and embodiment 2 is that the types of stabilizers are different, as shown below.

[0030] In Example 6: the stabilizer is obtained by mixing phosphatidylserine, soybean isoflavones, and liquid algae oil in a weight ratio of 2:2:9.

[0031] In Example 7: the stabilizer is obtained by mixing phosphatidylserine, soybean isoflavones, and liquid algae oil in a weight ratio of 6:5:1.

[0032] In Example 8: the stabilizer is obtained by mixing phosphatidylserine, soybean isoflavones, and liquid algae oil in a weight ratio of 10:3:1.

[0033] In Example 9: the stabilizer is obtained by mixing phosphatidylserine, soybean isoflavones, and liquid algae oil in a weight ratio of 8:1:3.

[0034] The other process parameters in the above embodiment are the same as those in embodiment 2.

[0035] Examples 10-17 Examples 10-17 respectively provide an oat composite extract and a preparation method thereof.

[0036] The difference between the above embodiment and embodiment 2 is that the enzymatic hydrolysis method is different, as shown below.

[0037] In Example 10: Enzymolysis: add 0.04g of enzymolysis agent A (composed of a mixture of β-amylase and flavor protease in a weight ratio of 3:0.2) to the oat composite raw pulp, adjust the pH to 5.5, heat to 50°C, enzymolyze for 50 minutes, heat to 95°C to inactivate the enzyme for 10 minutes; then cool to room temperature, add 0.005g of enzymolysis agent B (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 2.5:1.5), adjust the pH to 7.0, heat to 70°C, enzymolyze for 25 minutes, then heat to 95°C to inactivate the enzyme for 10 minutes; cool to obtain oat enzymolysate.

[0038] In Example 11: Enzymolysis: add 0.12g of enzymolysis agent A (composed of a mixture of β-amylase and flavor protease in a weight ratio of 1:0.8) to the oat composite raw pulp, adjust the pH to 5.5, heat to 70°C, enzymolyze for 20 minutes, heat to 95°C to inactivate the enzyme for 10 minutes; then cool to room temperature, add 0.005g of enzymolysis agent B (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 2.5:1.5), adjust the pH to 7.0, heat to 70°C, enzymolyze for 25 minutes, then heat to 95°C to inactivate the enzyme for 10 minutes; cool to obtain oat hydrolysate.

[0039] In Example 12: Enzymolysis: add 0.06g of enzymolysis agent A (composed of a mixture of β-amylase and flavor protease in a weight ratio of 1.5:0.6) to the oat composite raw pulp, adjust the pH to 5.5, heat to 55°C, enzymolyze for 50 minutes, heat to 95°C to inactivate the enzyme for 10 minutes; then cool to room temperature, add 0.005g of enzymolysis agent B (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 2.5:1.5), adjust the pH to 7.0, heat to 70°C, enzymolyze for 25 minutes, then heat to 95°C to inactivate the enzyme for 10 minutes; cool to obtain oat hydrolysate.

[0040] In Example 13: Enzymolysis: add 0.10g of enzymolysis agent A (composed of a mixture of β-amylase and flavor protease in a weight ratio of 2.5:0.4) to the oat composite raw pulp, adjust the pH to 5.5, heat to 65°C, enzymolyze for 40 minutes, heat to 95°C to inactivate the enzyme for 10 minutes; then cool to room temperature, add 0.005g of enzymolysis agent B (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 2.5:1.5), adjust the pH to 7.0, heat to 70°C, enzymolyze for 25 minutes, then heat to 95°C to inactivate the enzyme for 10 minutes; cool to obtain oat hydrolysate.

[0041] In Example 14: Enzymolysis: add 0.08g of enzymolysis agent A (composed of a mixture of β-amylase and flavor protease in a weight ratio of 2:0.3) to the oat composite raw pulp, adjust the pH to 5.5, heat to 60°C, enzymolyze for 45 minutes, heat to 95°C to inactivate the enzyme for 10 minutes; then cool to room temperature, add 0.002g of enzymolysis agent B (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 1:3), adjust the pH to 7.0, heat to 75°C, enzymolyze for 20 minutes, then heat to 95°C to inactivate the enzyme for 10 minutes; cool to obtain oat hydrolysate.

[0042] In Example 15: Enzymolysis: add 0.08g of enzymolysis agent A (composed of a mixture of β-amylase and flavor protease in a weight ratio of 2:0.3) to the oat composite raw pulp, adjust the pH to 5.5, heat to 60°C, enzymolyze for 45 minutes, heat to 95°C to inactivate the enzyme for 10 minutes; then cool to room temperature, add 0.008g of enzymolysis agent B (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 2:3), adjust the pH to 7.0, heat to 60°C, enzymolyze for 50 minutes, then heat to 95°C to inactivate the enzyme for 10 minutes; cool to obtain oat hydrolysate.

[0043] In Example 16: Enzymolysis: add 0.08g of enzymolysis agent A (composed of a mixture of β-amylase and flavor protease in a weight ratio of 2:0.3) to the oat composite raw pulp, adjust the pH to 5.5, heat to 60°C, enzymolyze for 45 minutes, heat to 95°C to inactivate the enzyme for 10 minutes; then cool to room temperature, add 0.005g of enzymolysis agent B (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 2:2), adjust the pH to 7.0, heat to 70°C, enzymolyze for 25 minutes, then heat to 95°C to inactivate the enzyme for 10 minutes; cool to obtain oat hydrolysate.

[0044] In Example 17: Enzymolysis: add 0.08g of enzymolysis agent A (composed of a mixture of β-amylase and flavor protease in a weight ratio of 2:0.3) to the oat composite raw pulp, adjust the pH to 5.5, heat to 60°C, enzymolyze for 45 minutes, heat to 95°C to inactivate the enzyme for 10 minutes; then cool to room temperature, add 0.005g of enzymolysis agent B (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 3:1), adjust the pH to 7.0, heat to 70°C, enzymolyze for 25 minutes, then heat to 95°C to inactivate the enzyme for 10 minutes; cool to obtain oat hydrolysate.

[0045] The other process parameters in the above embodiment are the same as those in embodiment 2.

[0046] Comparative Example Comparative Examples 1-3 Comparative Examples 1-3 respectively provide an oat composite extract and a preparation method thereof.

[0047] The difference between the comparative example and Example 2 is that the dosage of each component in the oat composite raw pulp is different, as shown in Table 1.

[0048] The other process parameters in the above comparative example are the same as those in Example 2.

[0049] Comparative Examples 4-5 Comparative Examples 4-5 respectively provide an oat composite extract and a preparation method thereof.

[0050] The difference between the comparative example and Example 2 is that the types of stabilizers are different, as shown below.

[0051] In Comparative Example 4: the stabilizer is obtained by mixing phosphatidylserine, soybean lecithin, and liquid algae oil in a weight ratio of 9:2:2.

[0052] In Comparative Example 5: the stabilizer is obtained by mixing phosphatidylserine and soy isoflavones in a weight ratio of 9:2.

[0053] The other process parameters in the above comparative example are the same as those in Example 2.

[0054] Comparative Examples 6-7 Comparative Examples 6-7 respectively provide an oat composite extract and a preparation method thereof.

[0055] The difference between the above comparative example and Example 2 is that the enzymatic hydrolysis method is different, as shown below.

[0056] In Comparative Example 6: Enzymolysis: add 0.08g of enzymolysis agent A (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 2.5:1.5) to the oat composite raw pulp, adjust the pH to 5.5, heat to 60°C, enzymolysis for 45min, heat to 95°C to inactivate the enzyme for 10min; then cool to room temperature, add 0.005g of enzymolysis agent B (composed of a mixture of β-amylase and flavor protease in a weight ratio of 2:0.5), adjust the pH to 7.0, heat to 70°C, enzymolysis for 25min, then heat to 95°C to inactivate the enzyme for 10min; cool to obtain oat hydrolysate.

[0057] In Comparative Example 7: Enzymolysis: add 0.005g of enzymolysis agent A (composed of a mixture of β-amylase and glucoamylase in a weight ratio of 2:0.5) to the oat composite pulp, adjust the pH to 5.5, heat to 70°C, enzymolyze for 25min, heat to 95°C to inactivate the enzyme for 10min; then cool to room temperature, add 0.08g of enzymolysis agent B (composed of a mixture of high-temperature resistant α-amylase and neutral protease in a weight ratio of 2.5:1.5), adjust the pH to 7.0, heat to 60°C, enzymolyze for 25min, then heat to 95°C to inactivate the enzyme for 10min; cool to obtain oat hydrolysate.

[0058] The other process parameters in the above comparative example are the same as those in Example 2.

[0059] Performance testing (1) Physical and chemical indicators of oat composite extract: According to the inspection method specified in Q / HLY0006S-2021 "Starch Sugar (Oat Composite Extract)", the physical and chemical indicators of the oat composite extracts prepared by the above-mentioned embodiment and the comparative example preparation process were tested respectively, and all met the requirements.

[0060] (2) Reducing sugar content: According to GB5009.7-2016 "Determination of reducing sugars in food", the reducing sugar content percentage (%) in the oat composite extracts prepared in the examples and the comparative examples was measured respectively. The higher the reducing sugar content percentage, the greater the degree of saccharification of the oat raw material.

[0061] (3) Antioxidant test: O 2 - Free radical scavenging rate The solid powder was prepared into a sample solution with a concentration of 0.5wt% using deionized water, 5mL of Tris-HCl buffer with a concentration of 0.04mol / L and pH=8.2 was taken, and placed in a 25℃ water bath for preheating for 20min, 1mL of the sample solution and 0.4mL of pyrogallol solution with a concentration of 25mmol / L were added, and after mixing evenly, the mixture was placed in a 25℃ water bath for reaction for 5min, and then 1mL of hydrochloric acid solution with a concentration of 8mol / L was added to terminate the reaction for 5min, and the absorbance value was measured at 325nm. The Tris-HCl buffer with a concentration of 0.04mol / L and pH=8.2 was used as a reference, and the absorbance value was measured at 325nm. At the same time, 1mL of deionized water was used to replace the sample solution as a blank control.

[0062] O 2 - The calculation formula of free radical scavenging rate is: 2 - Free radical scavenging rate (%) = [1-(absorbance value of sample / absorbance value of blank control)] × 100%.

[0063] (4) Stability The oat composite extracts stored at 4°C for 6 months and at room temperature for 6 months were used as samples and the same antioxidant test in experiment (3) was carried out to evaluate the stability of the samples; stability = antioxidant activity of the sample after storage for a period of time / antioxidant activity of the initial sample × 100%.

[0064] Test results: as shown in Table 2.

[0065] Table 2 Performance test results of oat composite extracts in Examples and Comparative Examples Combined with Table 2, by comparing the performance test results in the embodiment and the comparative example, it can be seen that the reducing sugar content of the oat composite extract prepared by the technical solution provided by the present application is 30.8-40.0%, the antioxidant activity is ≥76.3%, the stability of 6 months stored at 4°C is ≥78.3%, and the stability of 6 months stored at room temperature is ≥76.4%. The above test results show that the oat composite extract prepared by the present application has a suitable degree of saccharification and has strong antioxidant activity and stability, thereby broadening the application scope of the oat composite extract.

[0066] In Comparative Example 1, the amounts of the raw material components are not matched, the reducing sugar content in the oat composite extract is low, and the antioxidant activity is weak; in Comparative Example 2, an equal amount of rice flour is used instead of corn flour, and the reducing sugar content in the oat composite extract is high and the antioxidant activity is weak; in Comparative Example 3, no stabilizer is added, and the stability of the oat composite extract is poor; in Comparative Example 4, the stabilizer is obtained by mixing phosphatidylserine, soybean lecithin, and liquid algae oil in a weight ratio of 9:2:2, and the stability of the oat composite extract is poor; in Comparative Example 5, the stabilizer is obtained by mixing phosphatidylserine and soybean isoflavones in a weight ratio of 9:2, and the antioxidant activity and stability of the oat composite extract are poor; the specific steps of enzymatic hydrolysis in Comparative Examples 6-7 are not matched, and the comprehensive performance of the prepared oat composite extract is poor.

[0067] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing an oat composite extract, characterized in that: Specifically, the following steps are carried out in sequence: batching and slurry preparation, enzymatic hydrolysis, filtration and concentration, spray drying, crushing and screening, storage and transportation; The specific steps of the ingredient slurry preparation are: 800-960 parts by weight of oatmeal powder, 20-140 parts by weight of malt powder, and 20-60 parts by weight of corn flour are crushed, 4-6 times the weight of water of the raw materials are added, and stirred evenly; then 5-10 parts by weight of a stabilizer are added, and stirred evenly to obtain an oatmeal composite slurry; The stabilizer is obtained by mixing phosphatidylserine, soybean isoflavones, and liquid algae oil in a weight ratio of 1-10:1-10:1-10; The specific steps of enzymolysis are: adding 0.04-0.12 parts by weight of enzymolysis agent A to the oat composite raw pulp, heating to 50-70°C, enzymolysis for 20-50 minutes, and high temperature inactivating enzyme activity; then cooling to room temperature, adding 0.002-0.008 parts by weight of enzymolysis agent B, heating to 60-75°C, enzymolysis for 20-50 minutes, and high temperature inactivating enzyme activity; cooling to obtain oat enzymolysis product; The enzymolysis agent A is composed of a mixture of β-amylase and flavor protease in a weight ratio of 1-3:0.2-0.8; The enzymolysis agent B is composed of a mixture of thermostable α-amylase and neutral protease in a weight ratio of 1-3:1-3.

2. The method for preparing the oat composite extract according to claim 1, characterized in that: In the mixing and slurrying of ingredients, the dosage of each raw material component is: 840-920 parts by weight of oatmeal powder, 60-100 parts by weight of malt powder, and 30-50 parts by weight of corn flour.

3. The method for preparing the oat composite extract according to claim 1, characterized in that: The stabilizer is obtained by mixing phosphatidylserine, soybean isoflavones and liquid algae oil in a weight ratio of 8-10:1-3:1-3.

4. The method for preparing the oat composite extract according to claim 1, characterized in that: The specific steps of the enzymolysis are: adding 0.06-0.10 weight parts of enzymolysis agent A to the oat composite raw pulp, heating to 55-65°C, enzymolysis for 40-50 minutes, and high temperature inactivating the enzyme; then cooling to room temperature, adding 0.004-0.006 weight parts of enzymolysis agent B, heating to 65-75°C, enzymolysis for 20-30 minutes, and high temperature inactivating the enzyme; and obtaining oat enzymolysis product.

5. The method for preparing the oat composite extract according to claim 1, characterized in that: The specific steps of the enzymolysis are: adding 0.06-0.10 weight parts of enzymolysis agent A to the oat composite raw pulp, adjusting the pH to 5.0-6.0, heating to 55-65°C, enzymolysis for 40-50 minutes, and high temperature inactivating enzymes; then cooling to room temperature, adding 0.004-0.006 weight parts of enzymolysis agent B, adjusting the pH to 6.0-7.5, heating to 65-75°C, enzymolysis for 20-30 minutes, and high temperature inactivating enzymes; and obtaining oat enzymolysis products.

6. The method for preparing the oat composite extract according to claim 1, characterized in that: The enzymolysis agent A is composed of a mixture of beta-amylase and flavor protease in a weight ratio of 1.5-2.5:0.4-0.

6.

7. The method for preparing the oat composite extract according to claim 1, characterized in that: The enzymolysis agent B is composed of a mixture of thermostable α-amylase and neutral protease in a weight ratio of 2-3:1-2.

8. The method for preparing the oat composite extract according to claim 1, characterized in that: The process parameters of the spray drying are as follows: the air inlet temperature is 145-165°C, the air outlet temperature is 65-85°C, and the temperature in the tower is maintained at 75-90°C.

9. An oat composite extract, characterized in that: The method is prepared by the method described in any one of claims 1 to 8.

10. Use of the oat composite extract according to claim 9 in food and skin care products.

Images