Soy milk and preparation method thereof

Abstract

The present application provides soy milk and a preparation method thereof. The soy milk preparation method comprises the following steps: preparing a feed liquid using a raw material comprising soybean flour; mixing the feed liquid with cellulase and performing a primary enzymatic hydrolysis reaction to prepare an enzymatic hydrolysis liquid mixture; and mixing the enzymatic hydrolysis liquid mixture, roasted wheat flour, and protease, adding the protease and performing a secondary enzymatic hydrolysis reaction to prepare the soy milk. The primary enzymatic hydrolysis reaction using cellulase, followed by the addition of roasted wheat flour and the secondary enzymatic hydrolysis reaction using protease, not only reduces the beany odor and astringency of the soy milk and enhances the milky flavor, but also, due to the reduced overall particle size, improves the stability of the soy milk system, makes it smoother in taste, and reduces viscosity and sedimentation rate.

Description

Technical Field

[0001] The present application relates to the field of food processing technology, and in particular to soy milk and a preparation method thereof. Background Art

[0002] Soy milk is a milky white to pale yellow emulsion made from ground soybeans. Rich in nutrients such as soy protein, linoleic acid, linolenic acid, oligosaccharides, and soy lecithin, soy milk also contains a variety of vitamins and minerals, making it highly nutritious. With a rich, smooth, and non-greasy taste, soy milk is a healthy and nutritious beverage that is beneficial to drink regularly.

[0003] However, soy milk currently has common problems such as beany smell, strong astringency and insufficient milky flavor, or poor system stability and rough taste when no stabilizer is added. Summary of the Invention

[0004] Based on this, the present application provides a soy milk and a preparation method thereof, so as to reduce the beany smell and astringency of the soy milk and improve its milky flavor, taste and product stability.

[0005] A first aspect of the present application provides a method for preparing soy milk, comprising the following steps:

[0006] A feed solution is prepared using a raw material comprising soybean flour;

[0007] The feed liquid is mixed with cellulase to perform an enzymatic hydrolysis reaction to prepare an enzymatic hydrolysis solution mixture;

[0008] The enzymatic hydrolysis solution mixture, fried wheat flour and protease are mixed to carry out a secondary enzymatic hydrolysis reaction.

[0009] In some embodiments, the added amount of the fried wheat flour accounts for 3%-5% of the mass of the soybean flour.

[0010] In some embodiments, the method for frying the wheat flour comprises:

[0011] Fry the wheat flour at 150-200°C for 30-60 minutes.

[0012] In some embodiments, the protease comprises a neutral protease; and / or

[0013] The amount of the protease added is 0.2%-0.8% of the mass of the enzymatic hydrolysate mixture; and / or

[0014] The temperature of the secondary enzymatic hydrolysis reaction is 55° C.-65° C., and the time is 30 min-60 min.

[0015] In some embodiments, the amount of cellulase added is 0.2%-0.8% by mass of the feed solution; and / or

[0016] The temperature of the primary enzymatic hydrolysis reaction is 50° C.-55° C., and the time is 30 min-60 min.

[0017] In some embodiments, the method for preparing the feed solution comprises:

[0018] The raw materials are mixed with water, leaching, grinding and once sieving to prepare a slurry;

[0019] The slurry is subjected to enzyme inactivation and secondary sieving to prepare the feed liquid.

[0020] In some embodiments, the method for preparing the feed solution includes at least one of the following conditions:

[0021] (1) The mass volume ratio of the soybean powder to the water is 1 g: (4-6) mL;

[0022] (2) the extraction temperature is 90°C-95°C and the extraction time is 5 min-10 min;

[0023] (3) The primary screening is performed using a 120-200 mesh sieve;

[0024] (4) The enzyme inactivation temperature is 90°C-108°C and the time is 5 min-20 min;

[0025] (5) The secondary screening uses a 150-200 mesh sieve.

[0026] In some embodiments, after the secondary enzymatic hydrolysis step, the method further comprises:

[0027] Adding auxiliary materials to the enzymatic hydrolysis solution obtained from the secondary enzymatic hydrolysis reaction to prepare a soymilk mixture;

[0028] The soymilk mixture is post-processed to prepare the soymilk.

[0029] In some embodiments, the preparation method further comprises at least one of the following conditions:

[0030] (1) The auxiliary materials include white sugar and salt;

[0031] Optionally, the amount of white sugar added is 40%-50% of the mass of the soybean flour;

[0032] Optionally, the added amount of the salt is 0.8%-1.2% of the mass of the soybean flour;

[0033] (2) the post-processing includes inactivating enzymes, homogenizing and sterilizing the soymilk mixture;

[0034] Optionally, the temperature for inactivating the enzyme in the soymilk mixture is 85°C-100°C and the time is 10min-30min;

[0035] Optionally, the homogenization pressure is 30MPa-50MPa, and the time is 2min-3min;

[0036] Optionally, the sterilization temperature is 130°C-150°C, and the time is 8s-20s.

[0037] The second aspect of the present application provides a soy milk, which is prepared using the preparation method of the first aspect of the present application.

[0038] The soy milk preparation method provided above uses cellulase for a primary enzymatic hydrolysis reaction, and adds roasted wheat flour and uses protease for a secondary enzymatic hydrolysis reaction. This not only reduces the beany smell and astringency of the soy milk and enhances the milky flavor, but also, due to the smaller overall particle size, makes the soy milk system more stable, has a smoother taste, and has lower viscosity and sedimentation rate. DETAILED DESCRIPTION

[0039] To facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant embodiments. The following provides preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] In this application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0042] In this application, when referring to numerical ranges, unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges subsumed therein.

[0043] Only certain numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, each individually disclosed point or single value may itself serve as a lower limit or upper limit and be combined with any other point or single value, or with other lower limits or upper limits, to form an unspecified range.

[0044] The temperature parameters in this application, unless otherwise specified, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows for temperature fluctuations within the precision range of instrument control.

[0045] In the description of the invention, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0046] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. Unless otherwise specified, all technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0047] Unless otherwise specified, all steps of the present application can be performed sequentially or randomly, preferably sequentially.

[0048] Soy milk is a healthy and nutritious beverage, gaining popularity among consumers. However, current soy milk suffers from common issues such as a strong beany flavor, a strong astringency, and a lack of milky flavor. Without stabilizers, the system suffers from poor stability and a rough texture. Relevant technologies primarily use methods such as stir-frying, peeling, and adding milk powder to reduce the beany and astringent flavors in soy milk, but these methods have limited success.

[0049] Based on the above problems, the present application uses cellulase to carry out a primary enzymatic hydrolysis reaction to reduce the particle size of soybean fiber while fully exposing proteins, etc.; then, roasted wheat flour is introduced and a neutral protease is used to carry out a secondary enzymatic hydrolysis reaction to produce substances that are beneficial to enhancing the flavor of soy milk, thereby achieving the purpose of reducing the beany smell of soy milk, improving the astringency, enhancing the milky flavor, smoothness and product stability.

[0050] The first aspect of the present application provides a method for preparing soy milk, comprising the following steps: preparing a slurry using a raw material including soybean flour; mixing the slurry with cellulase, performing a primary enzymatic hydrolysis reaction, and preparing an enzymatic hydrolysis liquid mixture; and mixing the enzymatic hydrolysis liquid mixture, roasted wheat flour, and protease, and performing a secondary enzymatic hydrolysis reaction.

[0051] Using cellulase to perform an enzymatic hydrolysis reaction on the slurry can destroy the structure of the fiber, reduce the particle size, improve the stability of the product, and at the same time fully expose substances such as proteins, thereby increasing the contact between the protease and the substrate and improving the efficiency of the reaction.

[0052] By adding roasted wheat flour as a flavoring agent and using protease for a secondary enzymatic hydrolysis reaction, the small-molecule flavor compounds produced from the roasted wheat flour and soy milk enhance the soy milk's base flavor, enrich its mouthfeel, enhance its milky aroma, and further maintain the stability of the system. This manifests itself microscopically as a smaller overall particle size, resulting in greater system stability; macroscopically, this results in a smoother mouthfeel, lower viscosity, and reduced sedimentation.

[0053] As can be understood, the soymilk preparation method provided herein utilizes cellulase for a primary enzymatic hydrolysis reaction, followed by the addition of roasted wheat flour and a secondary enzymatic hydrolysis reaction using protease. This not only reduces the beany odor and astringency of the soymilk while enhancing its milky flavor, but also, due to the reduced overall particle size, improves the soymilk's system stability, resulting in a smoother mouthfeel, and lower viscosity and sedimentation rate. The resulting soymilk's quality is significantly improved, reducing its unpleasant flavor while enhancing its milky flavor and richness, as well as its system stability. Furthermore, this preparation method is relatively simple and highly feasible.

[0054] It should be noted that when preparing soymilk, a primary enzymatic hydrolysis using cellulase followed by a secondary enzymatic hydrolysis using protease is beneficial for breaking down the large fiber particles present in the soymilk system, reducing the product's particle size and improving its stability. However, if both cellulase and protease are used simultaneously, due to differences in their optimal reaction temperatures and other conditions, simultaneous addition of both enzymes will prevent both from reacting at their optimal temperature, leading to partial inhibition of enzyme activity and hindering industrial conversion. If a primary enzymatic hydrolysis using protease followed by a secondary enzymatic hydrolysis using cellulase is performed for an extended period of time, excessive protein degradation can occur, leading to the formation of large amounts of small-molecule flavor peptides and flavor amino acids, which can deteriorate the flavor of the soymilk.

[0055] When preparing soy milk, the raw materials include soybean flour and roasted wheat flour. As an example, clean, impurity-free non-GMO soybeans are selected, peeled, and then crushed through a 20-mesh sieve to obtain soybean flour, which is then set aside.

[0056] In some embodiments, the method for frying wheat flour comprises frying the wheat flour at 150° C.-200° C. for 30 min-60 min.

[0057] For example, the frying temperature of wheat flour can be, but is not limited to, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, or a range between any two of the above temperatures. When the wheat flour is frying at a temperature within the above range, the frying flavor is better and production operability is improved. When the temperature is below this range, the frying flavor is weaker or it takes longer to achieve the same flavor. When the temperature is above this range, the frying process is prone to burning, resulting in poor results.

[0058] The frying time of wheat flour can be, but is not limited to, 30 minutes, 33 minutes, 35 minutes, 38 minutes, 40 minutes, 42 minutes, 45 minutes, 48 ​​minutes, 50 minutes, 53 minutes, 55 minutes, 58 minutes, or 60 minutes, or a range between any two of the above times. When the wheat flour is frying for a time within the above range, the flavor quality of the frying wheat flour is improved. Frying for a longer time can affect both production efficiency and product quality. Frying for a shorter time can fail to enhance the flavor.

[0059] It should be noted that the frying temperature and frying time of the wheat flour can be combined in any appropriate manner, and both can be selected from any frying temperature and frying time described in this article.

[0060] When preparing soy milk, a feed liquid is prepared using raw materials including soybean flour. In some embodiments, the feed liquid preparation method includes: mixing the raw materials with water, extracting, grinding, and screening once to prepare a slurry; and inactivating enzymes in the slurry and screening a second time to prepare the feed liquid.

[0061] It should be noted that when the slurry is inactivated, the main purpose is to inactivate endogenous enzymes in soybeans, including urease, lipoxygenase, etc.

[0062] In some optional embodiments, when soybean flour is used to prepare the feed liquid, the mass volume ratio of soybean flour to water is 1g:(4-6)mL. For example, it can be, but is not limited to, 1g:4mL, 1g:4.1mL, 1g:4.2mL, 1g:4.3mL, 1g:4.4mL, 1g:4.5mL, 1g:4.6mL, 1g:4.7mL, 1g:4.8mL, 1g:4.9mL, 1g:5mL, 1g:5.1mL, 1g:5.2mL, 1g:5.3mL, 1g:5.4mL, 1g:5.5mL, 1g:5.6mL, 1g:5.7mL, 1g:5.8mL, 1g:5.9mL, 1g:6mL, or a range between any two of the above ratios. When the mass volume ratio of soybean flour to water is within the above range, it can ensure that the protein in the soybean flour is separated to the maximum extent after refining; if the amount of water is too small, the viscosity of the slurry is too high, the pulp residue is difficult to separate, and the protein utilization rate is low; if the amount of water is too large, the equipment processing capacity will increase, and the protein content of the extract will be low, which is not conducive to the implementation of industrial production.

[0063] As a possible embodiment, the extraction temperature after mixing soy flour and water is 90°C-95°C; for example, it can be, but is not limited to, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, or a range between any two of these temperatures. The extraction time is 5 minutes-10 minutes; for example, it can be, but is not limited to, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, or a range between any two of these times. Extracting soy flour and water at the aforementioned temperature and time settings not only improves the protein extraction rate in the soy flour, but also helps deactivate lipoxygenase, preventing the rancidity caused by fat oxidation during product production.

[0064] It should be noted that the temperature and time for extracting after mixing the soybean powder and water can be combined in any appropriate manner, and both can be selected from any extraction temperature and extraction time described herein.

[0065] In some optional embodiments, when preparing the slurry, a 120-200 mesh sieve is used for a single sieving. As an example, the mesh size of the sieve used for the single sieving can be, but is not limited to, 120 mesh, 130 mesh, 140 mesh, 150 mesh, 160 mesh, 170 mesh, 180 mesh, 190 mesh, 200 mesh, or a range between any two of the above mesh sizes.

[0066] In some optional embodiments, when preparing the feed solution, the enzyme inactivation temperature is 90°C-108°C; for example, it can be but not limited to 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C, 100°C, 101°C, 102°C, 103°C, 104°C, 105°C, 106°C, 107°C, 108°C, or a range between any two of the above temperatures. The enzyme inactivation time is 5 min-20 min; for example, it can be but not limited to 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, or a range between any two of the above times.

[0067] It should be noted that the temperature and time for inactivating the enzyme during the preparation of the feed solution can be combined in any appropriate manner, and both can be selected from any temperature and time for inactivating the enzyme during the preparation of the feed solution described herein.

[0068] As a possible embodiment, when preparing the feed liquid, a 150-200 mesh sieve is used for secondary screening. As an example, the mesh size of the sieve used for the secondary screening can be, but is not limited to, 150 mesh, 160 mesh, 170 mesh, 180 mesh, 190 mesh, 200 mesh, or a range between any two of the above mesh sizes.

[0069] After preparing the slurry, the prepared slurry is mixed with cellulase to perform an enzymatic hydrolysis reaction. In some embodiments, the amount of cellulase added is 0.2%-0.8% by weight of the slurry; for example, it can be, but is not limited to, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, or a range between any two of the above values. When the amount of cellulase added is within the above range, it is conducive to the full enzymatic hydrolysis reaction of the product cellulose.

[0070] As a possible embodiment, the temperature during the primary enzymatic hydrolysis reaction using cellulase is 50°C-55°C; for example, but not limited to, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, or a range between any two of the foregoing temperatures. When the temperature of the primary enzymatic hydrolysis reaction is within the foregoing range, the activity of the cellulase is relatively high.

[0071] The duration of a single enzymatic hydrolysis reaction using cellulase is 30-60 minutes; for example, it can be, but is not limited to, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, or a range between any two of the above times. A single enzymatic hydrolysis reaction time within this range is beneficial for reducing the product particle size to a level with a good taste. If the time is too short, the product particle size is too large, affecting both the taste and the stability of the product system. If the time is too long, a cooking smell is likely to appear, reducing the product taste.

[0072] It should be noted that the temperature and time of a single enzymatic hydrolysis reaction can be combined in any appropriate manner, and both can be selected from any temperature and time of a single enzymatic hydrolysis reaction described herein.

[0073] After the first enzymatic hydrolysis reaction, an enzymatic hydrolysis liquid mixture is obtained. The enzymatic hydrolysis liquid mixture is mixed with fried wheat flour, and then protease is added to carry out a second enzymatic hydrolysis reaction. In some embodiments, the amount of fried wheat flour added is 3%-5% of the mass of the soybean flour; for example, it can be but not limited to 3%, 3.3%, 3.5%, 3.8%, 4%, 4.3%, 4.5%, 4.7%, 5% or a range between any two of the above values. When the amount of fried wheat flour is within the above range, the flavoring effect of the wheat flour is better; below this range, the flavoring effect is not significant, and above this range, the wheat flour is easy to precipitate and the stability of the system deteriorates.

[0074] In some alternative embodiments, the protease comprises a neutral protease.

[0075] As a possible embodiment, the amount of protease added is 0.2%-0.8% by weight of the enzymatic hydrolysis mixture; for example, it can be, but is not limited to, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, or a range between any two of the above values. When the amount of protease added is within the above range, a good enzymatic hydrolysis effect can be achieved; an amount less than this range will affect production efficiency; an amount greater than this range will increase costs and easily cause excessive enzymatic hydrolysis, affecting product flavor.

[0076] For example, the temperature for the secondary enzymatic hydrolysis reaction using protease is 55°C-65°C; for example, it can be, but is not limited to, 55°C, 57°C, 60°C, 63°C, 65°C, or a range between any two of these temperatures. When the temperature of the secondary enzymatic hydrolysis reaction is within this range, the activity of the protease is relatively high, enabling efficient production.

[0077] The secondary enzymatic hydrolysis reaction using protease is performed for 30-60 minutes; for example, it can be, but is not limited to, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, or a range between any two of the foregoing times. When the secondary enzymatic hydrolysis reaction time is within the foregoing range, the degree of enzymatic hydrolysis is appropriate and the product flavor is better. A longer time may result in excessive enzymatic hydrolysis, while a shorter time may not achieve the desired enzymatic hydrolysis effect.

[0078] It should be noted that the temperature and time of the secondary enzymatic hydrolysis reaction can be combined in any appropriate manner, and both can be selected from any temperature and time of the secondary enzymatic hydrolysis reaction described herein.

[0079] After the secondary enzymatic hydrolysis reaction using a protease, the enzymatic hydrolysis solution obtained from the secondary enzymatic hydrolysis reaction is further processed. In some embodiments, after the secondary enzymatic hydrolysis step, the method further includes: adding auxiliary materials to the enzymatic hydrolysis solution obtained from the secondary enzymatic hydrolysis reaction to prepare a soymilk mixture; and post-processing the soymilk mixture to prepare the soymilk.

[0080] In some embodiments, the auxiliary materials include white sugar and salt.

[0081] In some optional embodiments, the amount of added white sugar is 40%-50% by weight of the soy flour, for example, but not limited to, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, or a range between any two of the above values. Thus, the product has an appropriate sweetness and is highly acceptable to consumers.

[0082] In some optional embodiments, the amount of salt added is 0.8%-1.2% by weight of the hydrolyzed liquid obtained from the secondary enzymatic hydrolysis reaction; for example, it can be, but is not limited to, 0.8%, 0.9%, 1%, 1.1%, 1.2%, or a range between any two of these values. This improves the richness of the product and increases consumer acceptance. If the amount added is too low, the effect is not significant. If the amount added is too high, the product has a strong salty taste, resulting in poor sensory quality of the soy milk.

[0083] In some embodiments, the post-processing includes inactivating enzymes, homogenizing, and sterilizing the soymilk mixture.

[0084] As a possible embodiment, the temperature for inactivating the enzyme in the soymilk mixture is 85°C-100°C, for example, but not limited to, 85°C, 88°C, 90°C, 93°C, 95°C, 98°C, 100°C, or a range between any two of the above temperatures. The duration is 10 min-30 min, for example, but not limited to, 10 min, 13 min, 15 min, 18 min, 20 min, 23 min, 25 min, 28 min, 30 min, or a range between any two of the above times.

[0085] In some optional embodiments, the homogenization pressure is 30 MPa-50 MPa, such as, but not limited to, 30 MPa, 31 MPa, 32 MPa, 33 MPa, 34 MPa, 35 MPa, 36 MPa, 37 MPa, 38 MPa, 39 MPa, 40 MPa, 41 MPa, 42 MPa, 43 MPa, 44 MPa, 45 MPa, 46 MPa, 47 MPa, 48 MPa, 49 MPa, 50 MPa, or any range between any two of the above pressures. The homogenization time is 2 min-3 min, such as, but not limited to, 2 min, 2.3 min, 2.5 min, 2.8 min, 3 min, or any range between any two of the above time periods.

[0086] It should be noted that the homogenization pressure and time can be combined in any appropriate manner, and both can be selected from any homogenization pressure and homogenization time described in this document.

[0087] In some optional embodiments, the homogenization is performed twice, and the pressure and time of each homogenization can be the same or different.

[0088] As a possible embodiment, the sterilization temperature is 130°C-150°C; for example, it can be, but is not limited to, 130°C, 132°C, 134°C, 136°C, 138°C, 140°C, 142°C, 144°C, 146°C, 148°C, 150°C, or a range between any two of the above temperatures. The sterilization time is 8s-20s; for example, it can be, but is not limited to, 8s, 10s, 12s, 14s, 16s, 18s, 20s, or a range between any two of the above times.

[0089] It should be noted that the sterilization temperature and time can be combined in any appropriate manner, and both can be selected from any sterilization temperature and sterilization time described in this document.

[0090] The second aspect of the present application provides a soy milk, which is prepared by the method of the first aspect of the present application.

[0091] The soymilk prepared using the method of the first aspect of this application exhibits significantly improved quality, reducing unpleasant soymilk flavor while enhancing its milky aroma, rich mouthfeel, and system stability. The soymilk has a viscosity of 13-15 cP (100 rpm, 2 minutes), a sedimentation rate of less than or equal to 3%, and a particle size distribution (D95) of less than 50 μm.

[0092] The following is a detailed description of the technical solutions of the present application in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. For experimental methods in the following examples where specific conditions are not specified, reference should be made to the instructions given in this application, or to experimental manuals or conventional conditions in the field, or to conditions recommended by the manufacturer, or to experimental methods known in the art.

[0093] In the following specific examples, the measured parameters of raw material components may have slight deviations within the range of weighing accuracy unless otherwise specified. For temperature and time parameters, acceptable deviations caused by instrument testing accuracy or operational accuracy are allowed.

[0094] Example 1

[0095] S1. Roast wheat flour at 190°C for 30 minutes to prepare roasted wheat flour. Select clean, impurity-free non-GMO soybeans, peel them, and grind them through a 20-mesh sieve to prepare soybean flour for later use.

[0096] S2. The soy flour in step S1 was mixed with water in a mass-to-volume ratio of 1 g:5 mL, extracted at 90°C for 10 min, and ground through a 150-mesh sieve to obtain a slurry; the slurry was heated to 100°C, the enzyme was inactivated for 10 min, and the mixture was passed through a 200-mesh sieve to obtain a sieve mixture for later use.

[0097] S3. After cooling the liquid in step S2 to 50°C, cellulase is added to perform an enzymatic hydrolysis reaction to obtain an enzymatic hydrolysis liquid mixture; wherein the amount of cellulase added accounts for 0.5% of the mass of the liquid; the temperature of the enzymatic hydrolysis reaction is 50°C and the time is 30min.

[0098] S4. After shearing and mixing the enzymatic hydrolysis solution mixture in step S3 and the roasted wheat flour, a neutral protease is added thereto for a secondary enzymatic hydrolysis reaction. After the secondary enzymatic hydrolysis reaction is completed, 45% of white sugar by weight of the soybean flour and 0.8% of salt by weight of the soybean flour are added to the enzymatic hydrolysis solution obtained by the secondary enzymatic hydrolysis reaction to prepare a soymilk mixture; wherein the amount of the added neutral protease accounts for 0.4% of the mass of the enzymatic hydrolysis solution mixture, and the amount of the added roasted wheat flour accounts for 3% of the mass of the soybean flour; the temperature of the secondary enzymatic hydrolysis reaction is 55°C, and the time is 30 minutes.

[0099] S5. The soy milk mixture obtained in step S4 is heated to 100°C, enzymes are inactivated for 10 minutes, and then homogenized at 50 MPa for 3 minutes and then at 30 MPa for 3 minutes. After homogenization, the mixture is sterilized at 130°C for 10 seconds and cooled to 35°C to obtain soy milk having a milky white color, a rich milky flavor, a smooth taste, and a moderate sweetness.

[0100] Example 2

[0101] The preparation methods of Example 2 are similar to those of Example 1, except that the temperature of the secondary enzymatic hydrolysis reaction in step S4 is 55° C. and the time is 60 min.

[0102] Example 3

[0103] The preparation method of Example 3 is similar to that of Example 1, except that: the temperature of the first enzymatic hydrolysis reaction in step S3 is 55°C and the time is 60 min; the amount of added fried wheat flour in step S4 accounts for 4% of the mass of soybean flour; the temperature of the second enzymatic hydrolysis reaction is 65°C and the time is 30 min.

[0104] Example 4

[0105] The preparation method of Example 4 is similar to that of Example 1, except that: the temperature of the first enzymatic hydrolysis reaction in step S3 is 55°C and the time is 30 min; the amount of added fried wheat flour in step S4 accounts for 5% of the mass of soybean flour; the temperature of the second enzymatic hydrolysis reaction is 65°C and the time is 60 min.

[0106] Comparative Example 1

[0107] In Comparative Example 1, the first and second enzymatic hydrolysis reactions were not performed during the preparation of soy milk, and no fried wheat flour was added. The details are as follows:

[0108] S1. Select clean, impurity-free non-GMO soybeans, peel them, and grind them through a 20-mesh sieve to produce soybean flour for later use.

[0109] S2. The soy flour in step S1 was mixed with water in a mass-to-volume ratio of 1 g:5 mL, extracted at 90°C for 10 min, and ground through a 150-mesh sieve to obtain a slurry; the slurry was heated to 100°C, the enzyme was inactivated for 10 min, and the mixture was passed through a 200-mesh sieve to obtain a sieve mixture for later use.

[0110] S3. After adding 45% of white sugar and 0.8% of salt to the soy flour by weight to the liquid obtained in step S2, the mixture was heated to 100°C to inactivate enzymes for 10 minutes. The mixture was then homogenized at 50 MPa for 3 minutes and then at 30 MPa for 3 minutes. After homogenization, the mixture was sterilized at 130°C for 10 seconds and cooled to 35°C to obtain soy milk.

[0111] Comparative Example 2

[0112] The difference between Comparative Example 2 and Example 3 is that: no cellulase is used for the primary enzymatic hydrolysis reaction, and no neutral protease is used for the secondary enzymatic hydrolysis reaction. The details are as follows:

[0113] S1. Roast wheat flour at 190°C for 30 minutes to prepare roasted wheat flour. Select clean, impurity-free non-GMO soybeans, peel them, and grind them through a 20-mesh sieve to prepare soybean flour for later use.

[0114] S2. The soy flour in step S1 was mixed with water in a mass-to-volume ratio of 1 g:5 mL, extracted at 90°C for 10 min, and ground through a 150-mesh sieve to obtain a slurry; the slurry was heated to 100°C, the enzyme was inactivated for 10 min, and the mixture was passed through a 200-mesh sieve to obtain a sieve mixture for later use.

[0115] S3. The liquid obtained in step S2 is shear-mixed with the roasted wheat flour, and 45% of the weight of the soy flour in white sugar and 0.8% of the weight of the soy flour in salt are added. The mixture is heated to 100°C to inactivate enzymes for 10 minutes. The mixture is then homogenized at 50 MPa for 3 minutes and then at 30 MPa for 3 minutes. After homogenization, the mixture is sterilized at 130°C for 10 seconds and cooled to 35°C to obtain soy milk. The amount of roasted wheat flour added is 4% of the weight of the soy flour.

[0116] Comparative Example 3

[0117] The difference between Comparative Example 3 and Example 4 is that no fried wheat flour is added during the secondary enzymatic hydrolysis reaction.

[0118] S1. Select clean, impurity-free non-GMO soybeans, peel them, and grind them through a 20-mesh sieve to produce soybean flour for later use.

[0119] S2. The soy flour in step S1 was mixed with water in a mass-to-volume ratio of 1 g:5 mL, extracted at 90°C for 10 min, and ground through a 150-mesh sieve to obtain a slurry; the slurry was heated to 100°C, the enzyme was inactivated for 10 min, and the mixture was passed through a 200-mesh sieve to obtain a sieve mixture for later use.

[0120] S3. After cooling the liquid in step S2 to 55°C, cellulase is added to perform an enzymatic hydrolysis reaction to obtain an enzymatic hydrolysis liquid mixture; wherein the amount of cellulase added accounts for 0.5% of the mass of the liquid; the temperature of the enzymatic hydrolysis reaction is 55°C and the time is 30min.

[0121] S4. A neutral protease is added to the hydrolyzate mixture in step S3 to perform a secondary enzymatic hydrolysis reaction. After the secondary enzymatic hydrolysis reaction is completed, 45% of white sugar by weight of the soy flour and 0.8% of salt by weight of the soy flour are added to the hydrolyzate obtained by the secondary enzymatic hydrolysis reaction to prepare a soymilk mixture; wherein the amount of the neutral protease added is 0.4% by weight of the hydrolyzate mixture; the temperature of the secondary enzymatic hydrolysis reaction is 65° C., and the time is 60 min.

[0122] S5. The soymilk mixture obtained in step S4 is heated to 100°C to inactivate enzymes for 10 minutes, and then homogenized at 50 MPa for 3 minutes and then at 30 MPa for 3 minutes; after homogenization, the mixture is sterilized at 130°C for 10 seconds and cooled to 35°C to obtain soymilk.

[0123] Comparative Example 4

[0124] The difference between Comparative Example 4 and Example 3 is that: cellulase and protease are used simultaneously for enzymatic hydrolysis at 55°C for 30 minutes, and fried wheat flour is added during the enzymatic hydrolysis reaction. The amount of fried wheat flour added is 4% of the mass of soybean flour. The details are as follows:

[0125] S1. Roast wheat flour at 190°C for 30 minutes to prepare roasted wheat flour. Select clean, impurity-free non-GMO soybeans, peel them, and grind them through a 20-mesh sieve to prepare soybean flour for later use.

[0126] S2. The soy flour in step S1 was mixed with water in a mass-to-volume ratio of 1 g:5 mL, extracted at 90°C for 10 min, and ground through a 150-mesh sieve to obtain a slurry; the slurry was heated to 100°C, the enzyme was inactivated for 10 min, and the mixture was passed through a 200-mesh sieve to obtain a sieve mixture for later use.

[0127] S3. The slurry in step S2 is cooled to 55°C and shear-mixed with the roasted wheat flour, and cellulase and neutral protease are added thereto for enzymatic hydrolysis to obtain an enzymatic hydrolyzate mixture; wherein the amount of roasted wheat flour added is 4% by weight of the soybean flour; the amount of cellulase added is 0.5% by weight of the slurry; and the amount of neutral protease added is 0.4% by weight of the slurry; the enzymatic hydrolysis reaction temperature is 55°C and the time is 30 minutes.

[0128] S4. After adding 45% of white sugar and 0.8% of salt to the soy flour by weight to the enzymatic hydrolyzate mixture in step S3, the mixture was heated to 100°C to inactivate the enzyme for 10 minutes, and then homogenized at 50 MPa for 3 minutes and then at 30 MPa for 3 minutes. After homogenization, the mixture was sterilized at 130°C for 10 seconds and cooled to 35°C to obtain soy milk.

[0129] Comparative Example 5

[0130] The difference between Comparative Example 5 and Example 3 is that neutral protease is first used for a primary enzymatic hydrolysis reaction, and then cellulase is used for a secondary enzymatic hydrolysis reaction. The details are as follows:

[0131] S1. Roast wheat flour at 190°C for 30 minutes to prepare roasted wheat flour. Select clean, impurity-free non-GMO soybeans, peel them, and grind them through a 20-mesh sieve to prepare soybean flour for later use.

[0132] S2. The soy flour in step S1 was mixed with water in a mass-to-volume ratio of 1 g:5 mL, extracted at 90°C for 10 min, and ground through a 150-mesh sieve to obtain a slurry; the slurry was heated to 100°C, the enzyme was inactivated for 10 min, and the mixture was passed through a 200-mesh sieve to obtain a sieve mixture for later use.

[0133] S3. The liquid in step S2 is cooled and shear-mixed with the roasted wheat flour, and then a neutral protease is added thereto for a primary enzymatic hydrolysis reaction to obtain a primary hydrolyzed liquid; wherein the amount of the roasted wheat flour added is 4% by weight of the soybean flour; the amount of the neutral protease added is 0.4% by weight of the liquid; the temperature of the primary enzymatic hydrolysis reaction is 65°C, and the time is 30 minutes.

[0134] S4. Add cellulase to the primary hydrolyzate in step S3 for a secondary enzymatic hydrolysis reaction to obtain a secondary enzymatic hydrolyzate; wherein the amount of cellulase added is 0.5% by mass of the primary hydrolyzate; the temperature of the secondary enzymatic hydrolysis reaction is 55°C, and the time is 60 minutes; after the secondary enzymatic hydrolysis reaction is completed, 45% of the mass of soy flour and 0.8% of the mass of soy flour are added to the secondary enzymatic hydrolyzate to obtain a soy milk mixture.

[0135] S5. The soymilk mixture is heated to 100°C to inactivate enzymes for 10 minutes, and then homogenized at 50 MPa for 3 minutes and then at 30 MPa for 3 minutes. After homogenization, the mixture is sterilized at 130°C for 10 seconds and cooled to 35°C to obtain soymilk.

[0136] The amount of roasted wheat added, the conditions for the first enzymatic hydrolysis reaction, and the conditions for the second enzymatic hydrolysis reaction in the above-mentioned embodiments and comparative examples are shown in Table 1, respectively.

[0137] Table 1

[0138]

[0139] Wherein, W represents the percentage of the added amount of fried wheat flour to the mass of soybean flour.

[0140] The following are the test results.

[0141] 1. Sensory evaluation

[0142] Anonymous, 30-person evaluations focused on reducing the product's beany and astringency, while enhancing its milky flavor and rich, smooth texture. These four indicators totaled 20 points, with higher scores representing better results. The sensory evaluation results were statistically analyzed. Table 2 shows the sensory evaluation results.

[0143] Table 2

[0144]

[0145] 2. Determination of total colony count

[0146] Using the national standard method [GB4789.2-2022], no microbial colonies were detected in the above embodiments and comparative examples.

[0147] 3. Physical and chemical index test results: The stability of the product system and the smoothness of the taste were analyzed and confirmed using viscosity, particle size, and sedimentation rate. The test methods are as follows:

[0148] (1) The viscosity of the sample was tested using a DV2THB digital viscometer (Brookfield) with the specific parameters of 100 rpm and 2 min.

[0149] (2) The particle size of the sample was measured using a laser particle size analyzer, and the shading degree was controlled at 15%-20%.

[0150] (3) Take an appropriate amount of sample and centrifuge it using a Beckman centrifuge at 4000 r / min for 5 min. Then discard the supernatant, weigh the amount of precipitate, and calculate the percentage of precipitate in the total sample.

[0151] The test results are shown in Table 3.

[0152] Table 3

[0153] index Viscosity (cP) Particle size (μm) D95 Precipitation rate (%) Example 1 14.40 46.88 2.41 Example 2 13.60 33.85 2.38 Example 3 14.00 39.47 2.52 Example 4 14.90 41.97 2.92 Comparative Example 1 16.00 51.86 3.49 Comparative Example 2 17.90 72.31 4.52 Comparative Example 3 13.8 37.02 2.13 Comparative Example 4 15.80 65.90 4.25 Comparative Example 5 13.4 27.9 1.79

[0154] Comparison of the results of Examples 1-4 and Comparative Example 1 in Table 2 shows that the preparation method provided by the present application can significantly reduce the beany smell and astringency of soy milk and significantly enhance the milky flavor of soy milk; the prepared soy milk has a rich aroma, a rich and smooth taste, and a moderate sweetness.

[0155] Comparison of the results of Examples 1-4 and Comparative Example 1 in Table 3 shows that the soymilk produced using the preparation method provided herein has a viscosity of 13 cP-15 cP, a sedimentation rate of less than 3%, and a product particle size distribution D95 of less than 50 μm. This indicates that the preparation method provided herein can reduce the overall particle size of soymilk, improve system stability, and reduce the viscosity and sedimentation rate of the finished product.

[0156] Comparison of the results of Example 3 and Comparative Example 2 in Tables 2-3 shows that enzymatic hydrolysis technology can reduce the overall particle size of soy milk, lower its viscosity and sedimentation rate, and significantly reduce the beany smell and astringency of the soy milk, enhance its milky flavor, and produce a smoother taste.

[0157] From the comparison of the results of Example 4 and Comparative Example 3 in Table 2, it can be seen that the milky flavor of soy milk can be significantly improved by adding roasted wheat flour.

[0158] Comparison of the results of Example 3 with Comparative Examples 4-5 in Table 2 shows that, when preparing soy milk, enzymatic hydrolysis using cellulase followed by protease can significantly reduce the beany odor and astringency of the soy milk, significantly enhance the milky flavor of the soy milk, and produce a smoother taste.

[0159] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0160] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for preparing soy milk, characterized in that: The steps include: A feed solution is prepared using a raw material comprising soybean flour; The feed liquid is mixed with cellulase to perform an enzymatic hydrolysis reaction to prepare an enzymatic hydrolysis solution mixture; The enzymatic hydrolysis solution mixture, fried wheat flour and protease are mixed to carry out a secondary enzymatic hydrolysis reaction; the protease includes a neutral protease.

2. The method for preparing soy milk according to claim 1, wherein: The added amount of the fried wheat flour accounts for 3%-5% of the mass of the soybean flour.

3. The method for preparing soy milk according to claim 1, wherein: The frying method of the fried wheat flour comprises: Fry the wheat flour at 150-200°C for 30-60 minutes.

4. The method for preparing soy milk according to claim 1, wherein: The amount of the protease added is 0.2%-0.8% of the mass of the enzymatic solution mixture; and / or The temperature of the secondary enzymatic hydrolysis reaction is 55° C.-65° C., and the time is 30 min-60 min.

5. The method for preparing soy milk according to claim 1, wherein: The amount of cellulase added is 0.2%-0.8% of the mass of the feed liquid; and / or The temperature of the primary enzymatic hydrolysis reaction is 50° C.-55° C., and the time is 30 min-60 min.

6. The method for preparing soy milk according to any one of claims 1 to 5, wherein: The preparation method of the feed liquid comprises: The raw materials are mixed with water, leaching, grinding and once sieving to prepare a slurry; The slurry is subjected to enzyme inactivation and secondary sieving to prepare the feed liquid.

7. The method for preparing soy milk according to claim 6, wherein: The preparation method of the feed solution includes at least one of the following conditions: (1) The mass volume ratio of the soybean powder to the water is 1 g: (4-6) mL; (2) the extraction temperature is 90°C-95°C and the extraction time is 5 min-10 min; (3) The primary screening is performed using a 120-200 mesh sieve; (4) The enzyme inactivation temperature is 90°C-108°C and the time is 5 min-20 min; (5) The secondary screening uses a 150-200 mesh sieve.

8. The method for preparing soy milk according to any one of claims 1 to 5 and 7, wherein: After the step of the secondary enzymatic hydrolysis reaction, the method further comprises: Adding auxiliary materials to the enzymatic hydrolysis solution obtained from the secondary enzymatic hydrolysis reaction to prepare a soymilk mixture; The soymilk mixture is post-processed to prepare the soymilk.

9. The method for preparing soy milk according to claim 8, wherein: The preparation method further comprises at least one of the following conditions: (1) The auxiliary materials include white sugar and salt; Optionally, the amount of white sugar added is 40%-50% of the mass of the soybean flour; Optionally, the added amount of the salt is 0.8%-1.2% of the mass of the soybean flour; (2) the post-processing includes inactivating enzymes, homogenizing and sterilizing the soymilk mixture; Optionally, the temperature for inactivating the enzyme in the soymilk mixture is 85°C-100°C and the time is 10min-30min; Optionally, the homogenization pressure is 30MPa-50MPa, and the time is 2min-3min; Optionally, the sterilization temperature is 130°C-150°C, and the time is 8s-20s.

10. A soy milk, characterized in that The product is prepared by the preparation method according to any one of claims 1 to 9.

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