Plant milk and use thereof

Abstract

A plant milk and a use thereof, relating to a use of plant milk in improving the bioavailability of plant protein. using a special process for germinating beans and fermenting rice, the protein content of the prepared plant milk is increased; additionally, the milk has good protein digestion characteristics, better facilitating absorption and utilization of the plant protein by the body. Thus, the vegetable milk can be used as a functional ingredient across a wide range of applications, and can be used to develop foodstuffs, health foods, etc. that have improved flavor, protein content, digestive absorption, and so on.

Description

Plant milk and its uses Technical field The present invention belongs to the technical field of functional substance research, and specifically relates to plant milk and its uses, and more specifically to the application of a plant milk in improving the bioavailability of plant protein. Background technology In recent years, with the continuous increase in people's demand for food in terms of low-carbon health and balanced nutrition, plant-based products with green, healthy and natural attributes have been highly favored by consumers, and plant-based foods (including plant milk) are experiencing a significant increase in market share. Currently, plant milk products are mainly made from soybeans, rice, almonds, oats and other legumes, grains, nuts or coconuts. For people with animal milk protein allergy, lactose intolerance or vegetarianism, it can be an important protein dietary source in daily life. At the same time, the cholesterol and saturated fatty acid content in plant milk is relatively low, which is helpful for blood lipid health. However, there are also some pain points in current plant milk products on the market, such as low protein content, lack of technical barriers, insufficient innovation compared with milk, serious product homogenization, single product category, etc. In addition, due to some anti-nutritional factors contained in plants (such as enzyme inhibitors, fibers, saponins and tannins, etc.), they can hinder the digestion process of proteins in the body, ultimately resulting in low protein bioavailability in plant milk products. In order to solve the problems of low protein content and low bioavailability in plant milk products, prior art has conducted research. For example, Citation Document 1 carried out amino acid complementation through soybeans and brown rice, and utilized the characteristics of increased protein content during soybean germination and improved flavor during brown rice fermentation to develop modulated soy milk, enhancing the added value of cereal products. Specifically, soybeans and brown rice were used as raw materials, the soybean germination and brown rice solid-state fermentation processes were optimized, and further, germinated soybeans and fermented brown rice were used as raw materials to study the processing technology and stability of modulated soy milk, and observe the flavor and stability during the storage of modulated soy milk, predict the storage time, and conduct quality evaluation at the same time to obtain modulated soy milk with balanced nutrition and unique flavor. Citation Document 2 discloses a production method of germinated polypeptide soy milk, and its production process includes: selecting soybeans, germinating, grinding, heat treatment, double enzymatic hydrolysis with a mixed enzyme, nutritional blending, homogenization sterilization and vacuum deodorization, and obtaining the finished product through aseptic filling. By adopting the mixed enzyme technology, soybean protein is hydrolyzed into polypeptide substances, and at the same time, substances such as cellulose and pectin are effectively enzymatically hydrolyzed, which is more conducive to the absorption of nutrients. It can be seen that currently, the problem of low protein content in soy milk is mainly solved by germinated beans, and the flavor is improved by fermented grains. The main method to solve the low bioavailability of plant proteins is the hydrolysis method, that is, using proteases to degrade proteins into small peptide molecules. However, the disadvantage of this method is that it easily causes obvious bitterness in plant milk products, with poor flavor, and compared with the unenzymatically hydrolyzed soy milk samples, its osmotic pressure is relatively high, which easily causes adverse reactions such as diarrhea after consumers drink it. Cited references: Cited reference 1: Wu Weichao. Joint application of germination / fermentation technology for the preparation of modified soy milk and quality evaluation [D]. Hebei University of Engineering, 2023. Cited reference 2: CN102150709A. Summary of the invention Problems to be solved by the invention Based on the above research on germinated beans and fermented grains in the prior art, when the present invention was studying the possible biological effects of relevant plant milk, it was unexpectedly found that using a special production process of "germination + fermentation" to process raw materials such as beans and grains not only can improve the protein content of plant milk products, but also endows them with good protein digestion characteristics, and at the same time, the generation of bad flavors is avoided during this process. Solutions for solving the problems The present invention discovers that the above technical problems can be solved by the following technical solutions: [1]. Use of plant milk in improving the bioavailability of plant proteins, characterized in that the preparation method of the plant milk comprises: Step of preparing germinated beans: Using beans to prepare germinated beans; Step of preparing fermented rice: Using rice to prepare fermented rice; and Step of processing slurry: Using the germinated beans and the fermented rice to prepare slurry, thereby obtaining the plant milk; Moreover, the solid content in the plant milk is 10 - 15% by mass. [2]. The use according to [1], characterized in that the beans include any one or more of soybeans, peas, kidney beans, mung beans, cowpeas, sword beans, lentils, chickpeas, and pigeon peas. [3]. The use according to [1], characterized in that the rice includes any one or more of japonica rice, indica rice, and glutinous rice. [4]. The use according to [3], characterized in that the rice is brown rice. [5]. The use according to any one of [1] to [4], characterized in that the improvement of the biological utilization rate of plant protein includes any one or more of the following: increasing the release amount of free amino acids during the digestion of plant protein in an organism, and reducing the molecular weight of plant protein after digestion in an organism. [6]. The use according to [5], characterized in that the increase in the release amount of free amino acids during the digestion of plant protein in an organism includes increasing the release amount during digestion in the stomach and / or intestine. [7]. The use according to [5], characterized in that the reduction of the molecular weight of plant protein after digestion in an organism includes increasing the number of molecules with a molecular weight less than 500 Da and / or reducing the number of molecules with a molecular weight greater than 5000 Da after the digestion of plant protein in the intestine of the organism. [8]. The use of a plant milk in the preparation of an edible product that helps improve the biological utilization rate of plant protein, characterized in that the plant milk is the plant milk defined according to any one of [1] to [7]. [9]. The use according to [8], characterized in that the improvement of the biological utilization rate of plant protein includes any one or more of the following: increasing the release amount of free amino acids during the digestion of plant protein in an organism, and reducing the molecular weight of plant protein after digestion in an organism.

[0010] . The use according to [8] or [9], characterized in that based on the total mass of the edible product, the content of the plant milk is 1 to 90% by mass.

[0011] . The use of an edible product to improve the biological utilization rate of plant protein, characterized in that the edible product contains the plant milk defined according to any one of [1] to [7] or is prepared from the plant milk defined according to any one of [1] to [7].

[0012] . The use according to

[0011] , characterized in that the improvement of the biological utilization rate of plant protein includes any one or more of the following: increasing the release amount of free amino acids during the digestion of plant protein in an organism, and reducing the molecular weight of plant protein after digestion in an organism.

[0013] . The use according to

[0011] or

[0012] , characterized in that based on the total mass of the edible product, the content of the plant milk is 1 to 90% by mass. Effects of the invention Based on the implementation of the above technical solutions, the present invention can achieve the following technical effects: Experimental data of the present invention show that the protein content in the plant milk prepared by a special process of germinating legumes and fermenting grains is increased. In particular, it endows the plant milk with good protein digestion characteristics, which is more conducive to the absorption and utilization of plant proteins by the body. Furthermore, such plant milk can be used as a functional raw material and thus has a wider range of applications, and more foods and health foods with excellent flavor, protein content, digestibility and absorption are developed. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1A: Analysis chart of total free amino acid release at the end of simulated gastric digestion. Figure 1B: Analysis chart of total free amino acid release at the end of simulated intestinal digestion. Figure 1C: Analysis chart of the release of each free amino acid at the end of simulated gastric digestion. Figure 1D: Analysis chart of the release of each free amino acid at the end of simulated intestinal digestion. Figure 2: Molecular weight distribution chart of each sample at different digestion stages. Figure 3A: Particle size distribution chart of the sample of Example 1 at different digestion stages. Figure 3B: Particle size distribution chart of the sample of Comparative Example 1 at different digestion stages. Figure 3C: Particle size distribution chart of the sample of Comparative Example 3 at different digestion stages. DETAILED DESCRIPTION OF THE INVENTION The following describes the embodiments of the present invention, but the present invention is not limited thereto. The present invention is not limited to the various components described below, and various changes can be made within the scope of the invention claimed, and the embodiments and examples obtained by appropriately combining the technical means disclosed in different embodiments and examples are also included in the technical scope of the present invention. In this specification, the numerical range expressed by "numerical value A to numerical value B" means a range including the end point numerical values A and B. In this specification, the numerical range expressed by "above" or "below" means a numerical range including this number. In this specification, the meaning expressed by "can" includes both the meaning of performing a certain process and the meaning of not performing a certain process. In this specification, the use of "optional" or "optional" means that certain substances, components, execution steps, applied conditions and other factors are used or not used. In this specification, unless otherwise specified, the "normal temperature" usually refers to the temperature at 23 ± 2 °C. In this specification, all unit names used are international standard unit names, and unless otherwise stated, the "%" used represents weight or mass percentage content. In this specification, the "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc. mentioned refer to the specific elements (e.g., features, structures, properties, and / or characteristics) related to the embodiment, which are included in at least one of the embodiments described herein, and may or may not exist in other embodiments. Additionally, it should be understood that the elements can be combined in various embodiments in any suitable manner. Unless otherwise defined, other technical and scientific terms used in this invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs of the present invention. (Plant milk) In the present invention, plant milk refers to a plant-based dairy product prepared using germinated beans and fermented rice as the main raw materials. In some embodiments, the plant milk described in the present invention is a product prepared using the following preparation method: Germinated bean preparation step: Use beans to prepare germinated beans; Fermented rice preparation step: Use rice to prepare fermented rice; and Slurry processing step: Use the germinated beans and the fermented rice to prepare a slurry, thereby obtaining the plant milk; Moreover, the solid content in the plant milk is 10-15% by mass. Germination can improve the degradation of natural enzymes in beans on their own anti-nutritional factors, and fermentation can break the complex protein cross-linking structure of plant proteins in rice. The present invention uses the process of germination + fermentation to prepare a special plant milk, making it not only have a relatively high content of protein, especially, but also have good protein digestion characteristics. I. Germinated bean preparation step In some embodiments, the germinated bean preparation step is a step of using beans to prepare germinated beans, and there is no particular limitation as long as it can make the beans used as raw materials germinate to improve the bioavailability of plant proteins. As the beans that can be used in the present invention, soybeans, peas, kidney beans, mung beans, cowpeas, sword beans, lentils, chickpeas, pigeon peas, etc. can be cited. They can be used alone or in combination of two or more. Considering cost, flavor, and protein digestion and absorption characteristics, it is preferably possible to use soybeans. In some embodiments, the germinated bean preparation step includes a pretreatment step, a germination step, and a freezing and thawing step of the beans. In some embodiments, the pretreatment step is to soak the beans in water at 15 - 42°C, preferably at 22 - 27°C, for 2 - 12 hours, preferably 3 - 8 hours. The water used in the pretreatment step can be tap water, groundwater, etc., without particular limitation. However, from the perspective of preventing precipitation of soybean protein contained in the plant milk, it is preferred to use water containing only a small amount of metal ions, such as soft water. The amount of water used can be set to 1 - 6 times, preferably 1 - 3 times, the mass of the dried beans. In addition, from the perspective of improving product quality and enhancing the edible taste, this pretreatment can also include the steps of removing impurities and cleaning the beans. Removing impurities refers to the step of removing defective beans, stones and other impurities mixed in the beans that affect product quality or edible taste, and cleaning refers to the step of washing with water, which can be carried out by the common impurity removal and cleaning methods in food processing. In some embodiments, the germination step is to germinate the pretreated beans at 15 - 35°C, preferably 20 - 30°C, for 4 - 36 hours, preferably 16 - 30 hours. During this period, it is preferred to spray water once every 1 - 5 hours, more preferably once every 3 - 5 hours. The temperature of the sprayed water can be 15 - 30°C, preferably 15 - 25°C. In some embodiments, the freezing step is to freeze the germinated beans at -4°C to -40°C for 6 - 60 hours. From the perspective of improving the biological utilization rate of protein, it is preferred to freeze the beans at -18°C to -35°C for 12 - 40 hours. In some embodiments, the thawing step is to place the frozen beans at 0 - 45°C for 1 - 50 hours. From the perspective of improving the biological utilization rate of protein, it is preferred to place the frozen beans at 0 - 35°C for 4 - 25 hours. II. Preparation steps of fermented rice In some embodiments, the preparation step of fermented rice is to use rice to prepare fermented rice. As long as it can ferment the rice used as raw material, there is no particular limitation. The rice to be fermented has no particular limitation as long as it can be used to make fermented glutinous rice. As the rice that can be used in the present invention, japonica rice, indica rice and glutinous rice can be cited. They can be used alone or in combination of two or more. From the aspects of cost, flavor and digestion characteristics, it is preferred to use brown rice, especially japonica brown rice, indica brown rice, glutinous rice brown rice, etc. In some embodiments, the preparation step of fermented rice includes a rice pretreatment step, a cooking step, an inoculation step, a fermentation step, and a sterilization step. In some embodiments, the rice pretreatment step is a step of making the rice to be fermented absorb water and soften. As long as the rice to be fermented can absorb water and soften, the pretreatment method is not particularly limited. For example, this pretreatment can be carried out by soaking the rice in water at normal temperature, such as 15 - 25°C, and then removing the water. Among them, the amount of water used in this soaking is 1 - 5 times the mass of dry rice, preferably 1 - 4 times the mass of dry rice; the soaking time is 2 - 12 hours, preferably 4 - 8 hours. In addition, from the perspective of improving product quality and enhancing the edible texture, this pretreatment can also include steps of removing impurities and cleaning the rice. Removing impurities refers to the step of removing impurities such as straws, rice bran, and stones that are mixed in the rice and affect product quality or edible texture. Cleaning refers to the step of washing with water, and can be carried out by the methods of removing impurities and cleaning commonly used in food processing. In some embodiments, the cooking step is a step of steaming the rice that has undergone the pretreatment step. As long as the rice that has undergone the pretreatment can be steamed until the rice grains expand, are hard on the outside and soft on the inside, and have no uncooked core, the cooking method is not particularly limited. For example, this cooking can be carried out by steaming the rice with added water. The amount of water used in steaming can be 0.5 - 4 times, preferably 1 - 3 times the mass of dry rice. As long as the rice grains can be steamed, the steaming time is not particularly limited and can be, for example, 25 - 75 min, preferably 40 - 65 min. The steaming temperature can be, for example, 90 - 100°C. In some embodiments, the inoculation step is a step of placing the cooked rice in a fermentation container, adding a fermentation bacterium, and stirring evenly. Any fermentation container in the food industry can be used as the fermentation container. From the perspective of obtaining fermented rice grains with a low alcohol content and a high soluble solids content, it is preferred that the volume of the container equipped for every 1 kg of dry rice is 10 - 40 L, and the thickness of the rice in the container is about 5 - 15 cm. Without being bound by theory, it is considered that if the volume is less than 10 L, the supply amount of oxygen is low, resulting in the promotion of anaerobic fermentation and thus more alcohol will be produced. If the volume is higher than 40 L, the supply amount of oxygen is too high, which is not conducive to the progress of fermentation. In addition, if the thickness of the rice in the container is too thick, the air permeability decreases, resulting in the promotion of anaerobic fermentation and thus more alcohol will be produced. From the perspective of considering cost and fermentation degree, it is preferred that the thickness of the rice in the container is 6 - 12 cm. The fermenting bacteria that can be used in the present invention include Rhizopus or Aspergillus. From the perspective of reducing the alcohol content, Rhizopus is preferably used because Rhizopus can produce a small amount of alcohol-forming enzymes and has a certain alcohol-producing ability, so it can carry out the process of saccharification and fermentation simultaneously. However, its alcohol-producing ability is not high, making the sweet fermented rice have a unique wine aroma in addition to the rice aroma, which is suitable for the preparation of plant milk mainly made of germinated soybeans and fermented brown rice. The addition amount of the fermenting bacteria is preferably 0.1-0.5% of the mass of dry rice. If it is lower than 0.1% of the mass of dry rice, it is not conducive to fermentation, while if it is higher than 0.5% of the mass of dry rice, the alcohol content increases and the soluble solid content decreases. In a preferred embodiment, 0.1-0.4% of the mass of dry rice of Rhizopus is added. In some embodiments, the fermentation step is a step of fermenting after sealing the inoculated fermentation container (for example, covering with a film, etc.). From the perspective of obtaining fermented rice with a high soluble solid content, a low alcohol content, being easy to digest and absorb, and having excellent odor, texture and taste, the fermentation temperature can be set at 25-38°C, preferably 27-33°C, and the fermentation time can be set at 30-48 h, preferably 32-40 h. In the present invention, it is preferred that when the soluble solid content in the fermented rice filtrate reaches 30%-50% as the fermentation end point. In some embodiments, the sterilization step is a step of sterilizing the fermented rice. The sterilization can be carried out by methods known in the food field. As a known sterilization method, for example, there can be mentioned a method of sterilizing the fermented rice by filling it in a heat-resistant package and steaming it at 90-100°C for 8-20 min. From the perspective of obtaining fermented rice with good taste, it is preferred to fill the fermented rice in a heat-resistant package and steam it at 90-100°C for 10-18 min for sterilization. The heat-resistant package used in the present invention is not particularly limited as long as it can package the fermented rice and can withstand high-temperature heating without introducing impurities or strange smells into the fermented rice, and heat-resistant packages commonly used in the food industry can be used. III. Slurry processing step In some embodiments, the slurry processing step is a step of preparing plant milk, especially the plant milk described in the present invention, using the germinated soybeans obtained in the germinated soybean preparation step and the fermented rice obtained in the fermented rice preparation step. In some embodiments, the slurry processing step can be a slurry (for example, plant milk slurry) processing step well-known to those skilled in the art. From the perspective of improving the biological utilization rate of plant protein, the slurry processing step of the present invention preferably includes a step of peeling the germinated soybeans obtained in the germinated soybean preparation step. In addition, the peeling step of the present invention may also include a step of washing the peeled germinated soybeans. Furthermore, from the perspective of preparing a plant milk with excellent taste and good stability, the slurry processing step of the present invention preferably includes a precooking step and a grinding step. In some embodiments, the precooking step is a step of precooking the germinated beans treated by the above-mentioned peeling step in water at 2 to 10 times, preferably 2 to 5 times the mass of the dried beans, at 90 to 100 °C, preferably 95 to 100 °C. Among them, from the perspective of preparing a germinated plant milk with excellent taste and good stability, it is preferred to add 0.01 to 0.2%, preferably 0.05 to 0.15% of sodium bicarbonate based on the total predetermined blending mass of the plant milk to the precooking water, and keep warm for 2 to 10 minutes, preferably 4 to 8 minutes. In some embodiments, the grinding step is a step of mixing the above-mentioned precooked germinated beans, the fermented rice prepared in the above-mentioned fermented rice preparation step, and the functional components in a weight ratio of 40:40:1 to 1:1:40, preferably 30:30:1 to 1:1:30, and then grinding to obtain a mixed milk slurry. This grinding can be carried out using a grinder that can be used in the food industry. In a specific embodiment, this grinding is carried out using a colloid mill. Functional components refer to medicinal and edible homologous materials that can endow plant milk with health care effects. There is no particular limitation as long as it is a medicinal and edible homologous material that can be added to food. As such functional components, for example, ginseng, wolfberry, polygonatum, kudzu root, smoked plum, Chinese yam, hawthorn, purslane, black sesame, dandelion, honey, wild jujube seed, tangerine peel, mint, coix seed, raspberry, roselle, chrysanthemum, lotus seed, longan, cassia seed, lily, nutmeg, cinnamon, hemp seed, etc. can be cited. From the perspective of obtaining a plant milk with good taste and suppressing the instability such as stratification caused by the use of germinated beans and fermented rice in the plant milk, hemp seed can be preferably used as the functional component in the present invention. In some embodiments, during the preparation process of the plant milk of the present invention, based on dry weight, the mass ratio of the peeled germinated beans to the fermented rice is 14 to 18:9, preferably 14 to 15:9. In some embodiments, the mixed milk slurry obtained in the above-mentioned grinding step can be directly used to prepare the plant milk of the present invention. However, from the perspective of improving product quality and enhancing the edible taste, the slurry processing step of the present invention preferably further includes a residue removal step after the above-mentioned grinding step. This residue removal step is a step of removing the residue in the slurry obtained in the above-mentioned grinding step. The residue removal method commonly used in the food industry can be adopted. As a specific embodiment, the mixed milk slurry obtained in the above-mentioned grinding step can be filtered through a 60-100 mesh sieve to remove residues, and the filtered mixed milk slurry after residue removal is obtained. mixed milk slurry. Furthermore, from the perspective of preparing a plant milk with excellent taste and good stability, the slurry processing step of the present invention preferably further includes an auxiliary material dissolution step. This auxiliary material dissolution step is a step of obtaining an auxiliary material emulsion by dissolving cereal powder in the filtered mixed milk slurry prepared in the above-mentioned grinding step. In some embodiments, the filtered mixed milk slurry prepared in the above-mentioned grinding step and the cereal powder are combined in a mass ratio of 1:1 to 5:1, preferably 3:1 to 5:1, and stirred at a temperature that does not cause denaturation of the proteins in the filtered mixed milk slurry and the cereal powder, for example, at a temperature of 40 to 60 °C, preferably 45 to 55 °C, until an emulsion is formed. The stirring time is not particularly limited as long as the cereal powder is dissolved to form an emulsion, for example, 15 to 30 min, preferably 15 to 25 min. The cereal powder used in the present invention is a powder prepared from one or more selected from rice, oats, beans, and beer malt. As the rice, those exemplified as the above-mentioned rice can be used. As the beans, those exemplified as the above-mentioned beans can be used. From the perspective of preparing a plant milk with excellent taste and good stability, relative to 30 to 300 parts of the germinated beans obtained in the above-mentioned peeling step, preferably 10 to 50 parts of cereal powder can be used, and preferably relative to 50 to 250 parts of the germinated beans obtained in the above-mentioned peeling step, 10 to 40 parts of cereal powder can be used. Furthermore, from the perspective of preparing a germinated plant milk with excellent taste and good stability, the slurry processing step of the present invention preferably further includes a sugar dissolution step. In some embodiments, the step of dissolving sugar is a step of mixing a sweetener and a stabilizer in 2 to 4 times the mass of water to obtain a sugar solution. For example, the sweetener and the stabilizer can be mixed in 2 to 4 times the mass of water and sheared at 60 to 90 °C, preferably 60 to 80 °C for 10 to 30 minutes, preferably 15 to 25 minutes to obtain a sugar solution. The sweetener used in the present invention can be a natural sweetener and / or a synthetic sweetener. There is no particular limitation as long as it can be used as a food additive. Examples of the sweetener that can be used in the present invention include, for example, white granulated sugar, xylitol, erythritol, stevioside, sucralose, etc. They can be used alone or in combination of two or more. In a specific embodiment, xylitol is preferably used. The stabilizer used in the present invention is not particularly limited as long as it can improve the stability of the plant milk mainly composed of germinated beans and fermented rice and does not affect the taste. Carrageenan, guar gum, gellan gum, xanthan gum, microcrystalline cellulose, and sodium tripolyphosphate can be used. They can be used alone or in combination of two or more to prepare a compound stabilizer. From the viewpoint of preparing a plant milk with excellent taste and good stability, 20 to 50 parts of the sweetener and 2 to 5 parts of the stabilizer are preferably mixed and then sheared in 2 to 4 times the mass of water at 60 to 90 °C for 10 to 30 minutes to obtain a sugar solution. From the viewpoint of improving the product quality, the obtained sugar solution is preferably filtered through a 60- to 200-mesh sieve. In addition, the slurry processing step of the present invention further includes preparing a plant milk from the filtered mixed milk slurry obtained in the above-mentioned grinding step, the auxiliary material emulsion obtained in the above-mentioned auxiliary material dissolving step, and the sugar solution obtained in the above-mentioned sugar dissolving step through a formulation step, a constant volume step, a homogenization step, and a sterilization step. In some embodiments, the formulation step is to stir the filtered mixed milk slurry obtained in the above-mentioned grinding step, the auxiliary material emulsion obtained in the above-mentioned auxiliary material dissolving step, and the sugar solution obtained in the above-mentioned sugar dissolving step at 50 to 60 °C for 10 to 15 minutes, and then adjust the pH of the slurry to pH 6.2 to 7.5, preferably pH 6.5 to 7.5 with a pH regulator. The pH regulator used in the present invention is also called an acidity regulator and is used to adjust the pH of the solution to the desired value. As the pH regulator that can be used in the present invention, a pH regulator whose action does not deteriorate the taste of the plant milk of the present invention is preferably used. Examples of such a pH regulator include sodium bicarbonate, sodium carbonate, and dipotassium hydrogen phosphate. They can be used alone or in combination of two or more. In some embodiments, the constant volume step is to add water to the slurry prepared in the formulation step to make it a desired volume The step of volume determination. Relative to 30 - 300 parts of the germinated beans obtained in the above peeling step, it is preferably diluted with water to a volume of 1000 parts and stirred until evenly mixed. From the perspective of improving product quality, after the volume determination step, detection and sensory evaluation can be preferably carried out, and then it is filtered through a 60 - 200 mesh sieve for subsequent steps. In some embodiments, the homogenization step is the step of heating the slurries after volume determination to 65 - 70 °C and then homogenizing. This homogenization can be carried out at least once. For example, it can be carried out 1 time, 2 times or more times. When carried out multiple times, the homogenization temperature and pressure for each time can be the same or different. For example, when carrying out 2 times of homogenization, the homogenization pressures can be 30 - 50 Mpa and 40 - 80 MPa respectively. In some embodiments, the sterilization step is the step of sterilizing the slurries after the homogenization step. The above sterilization can adopt the sterilization methods commonly used in the art. For example, it can adopt ultra - high temperature instantaneous sterilization (UHT sterilization), pasteurization, radiation sterilization (such as sterilization by ionizing radiation like γ or electron beam), filtration sterilization, autoclaving, pulsed electric field sterilization or their combination. The present invention preferably sterilizes the homogenized slurries through a UHT sterilization device under the conditions of 135 - 139 °C, 10 - 30 s, preferably 15 - 25 s. The slurry processing steps of the present invention are not limited to the above steps. Within the scope not affecting the effects of the present invention, other steps can also be included as needed. For example, in order to improve product reliability, the slurry processing steps of the present invention can further include an aseptic filling step and a finished product step. The aseptic filling step is the step of aseptically filling the slurry prepared through the above steps into a packaging container. As the packaging container, there is no particular limitation as long as it can be used in the food industry. The finished product step refers to the steps of online detection, coding, boxing, coding, palletizing the filled product as needed and then storing it in a warehouse. (Edible product) The edible product described in the present invention contains the above - mentioned plant milk or is prepared from the above - mentioned plant milk. In some specific embodiments, in the edible product, the plant milk can be used in the form of a dry matter, a solution or a slurry; preferably, it is used in the form of an emulsion. These emulsions usually have more than 3% by mass of protein. For the edible product of the present invention, in addition to the above necessary components, other optionally selected ingredients in food may be included according to the needs of the final product, such as other plants or plant extracts (such as vegetables, fruits, grains, nuts, legumes, etc. and their extracts), animal components (such as animal meat products, animal dairy products, etc.), microbial components (such as probiotics, postbiotics, etc.), functional supplements (such as vitamin supplements, mineral supplements, unsaturated fatty acid supplements, etc.), and any excipients acceptable in food (such as stabilizers, thickeners, sweeteners, emulsifiers, antioxidants, pigments, etc.). Such ingredients can be used in liquid, solid or semi-solid forms. The specific type of the edible product is not particularly limited in the present invention. For example, it can be an oral preparation (such as tablets, powders, granules, capsules, oral liquids, etc.), animal milk-based products (such as liquid milk, milk powder, milk cubes, milk-containing beverages, etc.), plant milk-based products (plant protein beverages such as soy milk, soy yogurt, etc.), candies (such as gel candies, tablet candies, etc.), pasta products (such as bread, cakes, biscuits, noodles, steamed buns, buns, dumplings, wontons, etc.), beverages (instant coffee, cereal powder, nut powder, lotus root powder, fruit and vegetable powder, etc.). Regarding the content of the plant milk in the edible product, there is no particular limitation in principle. From the perspective of meeting nutritional requirements, complying with relevant laws and regulations, and having the desired effect of improving the bioavailability of plant protein, based on the total mass (dry weight) of the edible product, the content of the plant milk is preferably 1-90% by mass. (Use for improving the bioavailability of plant protein) The present invention first proposes the concept that a plant milk mainly made from germinated beans and fermented rice can improve the bioavailability of plant protein without the need for additional treatment steps such as enzymatic hydrolysis of the protein components therein. Further, the above edible product can improve the bioavailability of plant protein. In some embodiments, the improvement of the bioavailability of plant protein includes any one or more of the following: increasing the release amount of free amino acids during the digestion of plant protein in the organism, and reducing the molecular weight of plant protein after digestion in the organism. In some embodiments, the increase in the release amount of free amino acids during the digestion of plant protein in the organism includes the release amount during digestion in the stomach and / or intestine. In some embodiments, the amino acids include essential amino acids (such as leucine, lysine, and phenylalanine, etc.) and non-essential amino acids (such as arginine, tyrosine, and glutamine, etc.). In some embodiments, the reduction of the molecular weight of plant protein after digestion in the organism includes reducing the molecular weight of plant protein after digestion in the stomach and / or intestine. In some embodiments, reducing the molecular weight of plant proteins after digestion in an organism includes increasing the number of molecules with a molecular weight less than 500 Da and / or reducing the number of molecules with a molecular weight greater than 5000 Da after intestinal digestion of plant proteins in the organism. And it can be understood that, with the total amount of plant proteins remaining unchanged, when the number of molecules with a molecular weight less than 500 Da increases after digestion, the number of molecules with other molecular weights greater than 500 Da will also decrease accordingly. The improvement of the biological utilization rate of plant proteins according to the present invention is not for the purpose of preventing and / or treating diseases. In addition, the edible products of the present invention are generally suitable for all populations, especially suitable for those with weak gastrointestinal functions, or those allergic to animal proteins, as well as vegetarians, etc. For populations with different characteristics, the components in the edible products can also be adjusted accordingly. Examples To more clearly illustrate the technical solutions of the present invention, the following further explains with specific examples, but it cannot be used to limit the present invention. These are only partial examples of the present invention. Unless otherwise specified, the instruments, reagents, materials, experimental animals, etc. used in the present invention can all be obtained through conventional commercial means. Example 1 (I) Preparation process of germinated beans 1. Pretreatment Wash the soybeans, and then soak them in pure water twice the mass of the soybeans for 6 h at an immersion temperature of 25°C. 2. Germination Place the soaked soybeans at 22°C for germination for 24 h, and spray water once every 3 h during this period. The temperature of the sprayed water is 18°C. 3. Freezing and thawing Place the germinated beans at -18°C for frozen storage for 36 h, and thaw the frozen germinated beans at 35°C for 8 h before use. (II) Preparation process of fermented rice 4. Pretreatment of fermented rice Remove impurities and wash the common brown rice, and then soak it in normal-temperature pure water twice the mass of the brown rice for 6 h, and filter out the water. 5. Steaming Add the common brown rice after filtering out the water to pure water 1.5 times the mass of the dry rice before soaking, place it in a steaming container, and then steam it at 100°C for 50 min. 6. Inoculation Place the steamed common brown rice in a special fermentation container (ensuring that a container with a volume of 20 L is equipped for every 1 kg of dry rice, and the thickness of the common brown rice does not exceed 10 cm), add 0.2% of the mass of the root mold based on the dry rice before soaking, and stir evenly. 7 Fermentation Cover the fermentation container with a film and ferment at 30 °C for 36 h until the soluble solids content of the fermented brown rice filtrate reaches 40%, which is the fermentation end point. 8. Packaging and sterilization Fill the fermented brown rice into a heat-resistant package and heat at 100 °C for 15 min to obtain sterilized fermented brown rice. (III) Preparation process of plant milk 9. Dehulling of germinated soybeans Take out 125 parts of the above germinated soybeans, wash them after dehulling. 10. Pre-boiling of germinated soybeans Add the dehulled germinated soybeans to 100 °C hot water with a mass 4 times that of the germinated soybeans for pre-boiling. Add 0.1% of sodium bicarbonate based on the total predetermined blending mass of the plant milk to the pre-boiling water, dissolve completely, and keep warm for 5 min. 11. Mixing and grinding Mix the pre-boiled germinated soybeans, sterilized fermented brown rice and hemp seeds in a weight ratio of 25:15:1 (dry weight ratio 12.5:7.5:1), and pump them into a colloid mill with the pre-boiling water pump for grinding 3 times to obtain a mixed milk slurry. 12. Residue removal Filter the mixed milk slurry through an 80-mesh sieve to remove residues, obtaining a filtered liquid of the mixed milk slurry. 13. Sugar dissolution Mix 35 parts of xylitol with 3 parts of stabilizers (2 parts of carrageenan and 1 part of guar gum), add the mixture to hot water at 70 °C with a mass 3 times that of the mixture after mixing evenly, keep warm and shear for 20 min. The completely dissolved syrup is filtered through an 80-mesh sieve and then enters the blending tank. 14. Dissolution of auxiliary materials Take a part of the filtered liquid of the mixed milk slurry (with a mass 3 times that of the cereal powder) and add it to the auxiliary material dissolution tank, put in 20 parts of cereal powder (the weight ratio of rice, soybeans, and beer malt is 1:1:2), keep warm and stir at 50 °C for 20 min to obtain an auxiliary material emulsion. 15. Blending Add the filtered liquid of the mixed milk slurry, the auxiliary material emulsion and the sugar solution to the blending tank in sequence, stir at 50 °C for 15 min until evenly mixed. Then add sodium bicarbonate to adjust the pH value of the liquid material to 7.0. 16. Volume fixing Add water to the blending tank to fix the volume to 1000 parts, keep stirring until evenly mixed. After the semi-finished product passes the sensory evaluation and meets the detection indexes, it can enter the homogenization process after passing through an 80-mesh sieve. 17. Homogenization Heat the liquid material after volume fixing to 65 °C and homogenize it twice. The homogenization pressure is: 35 MPa for the first time and 40 MPa for the second time. 18. UHT The homogenized liquid material is sterilized by passing through a UHT sterilization device, and the sterilization parameters are: 135°C, 15 s. 19. Aseptic filling The sterilized liquid material enters the packaging container through aseptic filling. 20. Finished product After filling, the product enters the warehouse after on-line inspection, coding, and boxing. The solid content of the plant milk obtained in this example is 13.0% by mass. Example 2 (I) Preparation process of germinated beans 1. Pretreatment After washing the soybeans, soak them in pure water 2 times the weight of the soybeans for 6 h at an immersion temperature of 25°C. 2. Germination Place the soaked soybeans at 22°C for germination for 26 h, and spray water once every 3 h during this period. The temperature of the sprayed water is 20°C. 3. Freezing and thawing Place the germinated beans at -35°C for frozen storage for 15 h, and thaw the frozen germinated beans at 35°C for 9 h before use. (II) Preparation process of fermented rice 4. Pretreatment of fermented rice After removing impurities and washing the common brown rice, soak it in normal-temperature pure water 2 times the mass of the brown rice for 6 h, and filter out the water. 5. Steaming Add the common brown rice after filtering out the water to pure water 1.5 times the mass of the dry rice, place it in a steaming container, and then steam it at 100°C for 50 min. 6. Inoculation Place the steamed common brown rice in a special fermentation container (ensure that each 1 kg of dry rice is equipped with a container with a volume of 20 L, and the thickness of the common brown rice does not exceed 10 cm), add 0.2% of the mass of the dry rice before soaking of Rhizopus, and stir evenly. 7 Fermentation Cover the fermentation container with a film, ferment it at 30°C for 36 h, and when the soluble solid content of the filtrate of the fermented brown rice reaches 40%, it is the fermentation end point. 8. Packaging and sterilization Fill the fermented brown rice into a heat-resistant package, and heat it at 100°C for 15 min to obtain sterilized fermented brown rice. (III) Preparation process of plant milk 9. Dehulling of germinated beans Take out 125 portions of the above germinated soybeans, wash them after dehulling. 10. Pre-boiling of germinated beans Add the peeled broad beans to hot water at 100°C, which is 4 times the mass of the broad beans. Add sodium bicarbonate accounting for 0.1% of the total predetermined blending mass of the plant milk to the hot water for precooking. Dissolve it completely and keep warm for 5 minutes. 11. Mixing and grinding Mix the precooked broad beans, sterilized fermented brown rice, and hemp seeds in a weight ratio of 30:15:1 (dry weight ratio of 15:7.5:1), and pump the mixture and the precooked water into a colloid mill for grinding 3 times to obtain a mixed milk slurry. 12. Dross removal Filter the mixed milk slurry through an 80-mesh sieve to remove dross, obtaining a filtered liquid of the mixed milk slurry. 13. Sugar dissolution Mix 35 parts of xylitol with 3 parts of stabilizers (2 parts of carrageenan and 1 part of microcrystalline cellulose). After mixing evenly, add it to hot water at 70°C, which is 3 times the mass, and keep warm and shear for 20 minutes. The completely dissolved syrup is filtered through an 80-mesh sieve and then enters the blending tank. 14. Auxiliary material dissolution Take a part of the filtered liquid of the mixed milk slurry (3 times the mass of the cereal powder) and add it to the auxiliary material dissolution tank. Put in 20 parts of cereal powder (the weight ratio of rice, soybeans, and beer malt is 1:1:2), keep warm and stir at 50°C for 20 minutes to obtain an auxiliary material emulsion. 15. Blending 15. Blending Add the filtered liquid of the mixed milk slurry, the auxiliary material emulsion, and the sugar solution to the blending tank in sequence, and stir at 50°C for 15 minutes until evenly mixed. Then add sodium bicarbonate to adjust the pH value of the liquid material to 7.0. 16. Volume fixing Add water to the blending tank to fix the volume to 1000 parts, and keep stirring until evenly mixed. After the semi-finished product passes the sensory evaluation and meets the detection indicators, it can enter the homogenization process after passing through an 80-mesh filter screen. 17. Homogenization Heat the liquid material after volume fixing to 65°C and then homogenize it twice. The homogenization pressure is: 35 Mpa for the first time and 40 Mpa for the second time. 18. UHT Pass the liquid material after homogenization through a UHT sterilization device for sterilization. The sterilization parameters are: 135°C, 15 s. 19. Aseptic filling The liquid material after sterilization enters the packaging container through aseptic filling. 20. Finished product The product after filling enters the warehouse after on-line inspection, coding, and boxing. The solid content of the plant milk obtained in this example is 12.6% by mass. Example 3 (I) Preparation process of germinated beans 1. Pretreatment After washing the soybeans, soak them in pure water with a mass twice that of the soybeans for 6 h at an immersion temperature of 25 °C. 2. Germination Place the soaked soybeans at 22 °C for germination for 28 h, and spray water once every 3 h during this period. The temperature of the sprayed water is 18 °C. 3. Freezing and thawing Place the germinated beans at -35 °C for frozen storage for 48 h, and thaw the frozen germinated beans at 25 °C for 8 h before use. (2) Preparation process of fermented rice 4. Pretreatment of fermented rice After removing impurities and washing the common brown rice, soak it in normal-temperature pure water with a mass twice that of the brown rice for 6 h, and filter out the water. 5. Steaming Add the common brown rice after filtering out the water to pure water with a mass equal to that of the dry rice, place it in a steaming container, and then steam it at 100 °C for 50 min. 6. Inoculation Place the steamed common brown rice in a special fermentation container (ensure that a container with a volume of 20 L is equipped for every 1 kg of dry rice, and the thickness of the common brown rice does not exceed 10 cm), add Rhizopus with a mass of 0.15% of the dry rice before soaking, and stir evenly. 7. Fermentation Cover the fermentation container with a film, ferment it at 30 °C for 36 h, and the fermentation end point is reached when the soluble solid content of the filtrate of the fermented brown rice reaches 40%. 8. Packaging and sterilization Fill the fermented brown rice into a heat-resistant package, heat it at 100 °C for 15 min to obtain sterilized fermented brown rice. (3) Preparation process of plant milk 9. Dehulling of germinated beans Take out 125 parts of the above germinated soybeans, wash them after dehulling. 10. Pre-boiling of germinated beans Add the dehulled germinated beans to hot water at 100 °C with a mass four times that of the germinated beans for pre-boiling. Add sodium bicarbonate with a mass of 0.1% of the total predetermined blending mass of the plant milk to the pre-boiling water, dissolve it completely, and keep it warm for 5 min. 11. Mixing and grinding Mix the pre-boiled germinated beans, sterilized fermented brown rice and hemp seeds in a weight ratio of 28:18:1 (dry weight ratio 14:9:1), and pump them into a colloid mill with the pre-boiling water for grinding three times to obtain a mixed milk slurry. 12. Residue removal Filter the mixed milk slurry through an 80-mesh sieve to remove residues, and obtain a filtered solution of the mixed milk slurry. 13. Sugar dissolution Mix 35 parts of xylitol with 3 parts of stabilizers (0.5 part of carrageenan, 2 parts of gellan gum, 0.5 part of microcrystalline cellulose), and after mixing evenly, add it to 3 times the mass of hot water at 70 °C, and keep warm and shear for 20 min. The syrup after complete dissolution is filtered through a 80-mesh sieve and then enters the blending tank. 14. Dissolution of excipients Take a part of the filtered mixed milk slurry (3 times the mass of the cereal powder) and add it to the excipient dissolution tank, put in 20 parts of cereal powder (the weight ratio of rice, soybeans, and beer malt is 1:1:2), and stir at 50 °C for 20 min to obtain an excipient emulsion. 15. Blending Add the filtered mixed milk slurry, excipient emulsion, and sugar solution to the blending tank in sequence, stir at 50 °C for 15 min until evenly mixed. Then add sodium bicarbonate to adjust the pH value of the liquid material to 7.0. 16. Volume fixing Add water to the blending tank to fix the volume to 1000 parts, keep stirring until evenly mixed. After the semi-finished product passes the sensory evaluation and meets the detection indexes, it can enter the homogenization process after passing through an 80-mesh filter screen. 17. Homogenization Heat the liquid material after volume fixing to 65 °C and then homogenize it twice. The homogenization pressure is: 35 MPa for the first time and 40 MPa for the second time. 18. UHT Pass the homogenized liquid material through a UHT sterilization device for sterilization. The sterilization parameters are: 135 °C, 15 s. 19. Aseptic filling Fill the sterilized liquid material into the packaging container through aseptic filling. 20. Finished product The filled product enters the warehouse after on-line detection, coding, and boxing. The solid content of the plant milk obtained in this example is 13.2% by mass. Comparative example 1 Compared with Example 1, germinated beans are not used, and ordinary soybeans are directly used to process and prepare plant milk, and other steps are the same. The solid content of the plant milk obtained in this comparative example is 8.7% by mass. Comparative example 2 Compared with Example 1, fermented brown rice is not used, and ordinary brown rice is directly used to process and prepare plant milk, and other steps are the same. The solid content of the plant milk obtained in this comparative example is 9.6% by mass. Comparative example 3 Compared with Example 1, germinated beans and fermented brown rice are not used, and ordinary soybeans and ordinary brown rice are directly used to prepare plant milk, and other steps are the same. The solid content of the plant milk obtained in this comparative example is 7.9% by mass. Test Example 1 1) Comparison of Protein Contents of Samples in Each Scheme According to the first method in GB 5009.5-2016 "National Food Safety Standard - Determination of Protein in Foods" - the Kjeldahl method, the protein contents in the samples prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were determined (the protein conversion factor was 6.25). The results are shown in Table 1 below. Table 1 Protein Contents of Samples in Each Scheme Note: The same letters indicate no significant difference at the P>0.05 level; different letters indicate significant difference at the P<0.05 level. The same applies hereinafter. As can be seen from the above table, among each scheme, the protein contents of the plant milk samples prepared in Examples 1 to 3 and Comparative Example 2 are relatively close, and there is no significant difference among the samples; however, compared with Example 1, the protein contents of the plant milk samples prepared in Comparative Examples 1 and 3 are significantly reduced. The above results show that compared with ungerminated soybeans, using germinated soybeans (sprouted beans) to prepare plant milk helps to increase the protein content of the samples; whether brown rice is fermented has little effect on the protein content of plant milk. 2) In Vitro Digestion Test of Samples in Each Scheme Referring to the in vitro simulated digestion model proposed by INFOGEST 2.0 and making slight modifications, the samples prepared in Example 1 and Comparative Examples 1 to 3 were subjected to in vitro simulated digestion. To ensure that the protein contents in the digestion substrates were equal, based on the protein mass of the sample obtained in Comparative Example 3, the other samples with equal protein mass were diluted to 10 mL with water respectively. The specific digestion process was as follows: The pH value of the simulated digestive juice was adjusted with 2 mol / L HCl or NaOH. The sample containing 250 mg of protein was made up to 10 mL with distilled water, and then 10 mL of simulated gastric juice containing pepsin (the final concentration in gastric digestion was 2000 U / mL) was added. It was simulated gastric digestion for 2 h under the conditions of 37 °C and 200 rpm in a water bath. After that, the pH value of the digestive juice was adjusted to 7.0, and 20 mL of simulated intestinal juice containing a mixture of porcine pancreatic trypsin (the final concentration of the final mixture was 100 U / mL) and porcine bile (the final concentration of the final mixture was 10 mM) was added. It was simulated intestinal digestion for 3 h under the conditions of 37 °C and 200 rpm in a water bath. At 0 min (G0), 60 min (G60), and 120 min (G120) of gastric digestion and 60 min (I60), 120 min (I120), and 180 min (I180) of intestinal digestion, 0.5 mL of the sample was taken respectively, boiled for 10 min to terminate digestion. Part of the digestive juice was centrifuged at 8000 g for 5 min, and the supernatant obtained by centrifugation was used to measure the release amount of free amino acids to evaluate the in vitro digestibility of proteins in each sample. At the same time, the molecular weight distribution of the digestive juice samples was measured for Evaluate the digestion characteristics of each sample. ① Determination of free amino acid release Method: Take 500 μL of the diluted supernatant, mix it with 50 μL of pH 8.0 phosphate buffer and 50 μL of ninhydrin reagent, heat in a boiling water bath for 16 min, then immediately cool to room temperature. Take 100 μL of the above reaction solution and add it to 1 mL of distilled water and mix well. Detect the absorbance at 570 nm by an enzyme-linked immunosorbent assay (ELISA) reader. Further compare and analyze the absorbance with the standard curve of L-leucine, and the results are expressed as leucine equivalents (unit: mmol / L). Results: As can be seen from Table 2, at the end points of gastric digestion and intestinal digestion, the free amino acid release of the samples was: Example 1 > Comparative Example 2 > Comparative Example 1 > Comparative Example 3. This shows that the plant milk prepared from germinated soybeans and fermented brown rice can release more free amino acids during gastrointestinal digestion, which helps to promote the absorption and utilization of proteins. Table 2 Free amino acid release of the samples in each scheme during in vitro digestion ② Quantitative determination of free amino acid release Method: Dilute the samples at the digestion zero point (G0), the end point of gastric digestion (G120), and the end point of intestinal digestion (I180) with ultrapure water at a ratio of 1:3, and use a high-performance liquid chromatography-tandem mass spectrometry system (HPLC-MS / MS) to derivatize and quantitatively analyze 20 free amino acids in the samples. Calculate the release amount of each free amino acid at the end of gastric / intestinal digestion respectively (formula: release amount of each free amino acid at the end of gastric / intestinal digestion = measured content of G120 / I180 - measured content of G0), and further calculate the total free amino acid release amount (that is, the sum of the release amounts of each free amino acid). The operation of HPLC-MS / MS is as follows: Each sample is divided into two equal parts, which are used to determine tryptophan and other amino acids respectively. When determining tryptophan, add 4 mol / L LiOH to the sample, and when determining other amino acids, add 6 mol / L HCl to the sample. Protect with nitrogen, and digest at 110 °C for 24 h. Take 100 μL of the digestion solution for rotary evaporation and dry it with nitrogen, then add 1 mL of ultrapure water to redissolve for use. Mix the mixed amino acid standard, the sample to be tested (50 μL) and the protein precipitant (50 μL) evenly, and centrifuge at 13200 r / min and -4 °C for 4 min. Take 8 μL of the supernatant, mix it with 42 μL of the labeling buffer, centrifuge briefly, then add 20 μL of the derivatizing agent and mix, and derivatize at 55 °C for 15 min. After derivatization, cool the sample to 4 °C, mix well and centrifuge briefly, take 50 μL of the derivatized sample for on-machine testing and quantitative analysis. Liquid phase conditions: chromatographic column MSLab 45+AA-C 18(150 mm × 4.6 mm, 5 μm); Column temperature: 50 °C; Flow rate: 1.0 mL / min; Injection volume: 3 μL. Mobile phase: Mobile phase A: ultrapure water containing 0.1% (V / V) formic acid, Mobile phase B: acetonitrile containing 0.1% (V / V) formic acid. The gradient elution program is shown in Table 3 below. Mass spectrometry conditions: Ion source: +ESI electrospray ionization source; Scanning mode: MRM multiple reaction monitoring; CUR: 20 psi (curtain gas); IS: +5500 V (spray voltage); CAD: Medium (collision gas); CXP: 2.0 (collision cell exit voltage); GS1: 55 psi (nebulizing gas); TEM: 500 °C (nebulizing temperature); EP: 10 (injection voltage); GS2: 60 psi (auxiliary gas). Table 3 Concentration gradient Results: As can be seen from Figure 1A, at the end of simulated gastric digestion, the order of the total free amino acid release amounts of each sample from large to small is: Example 1 (111.79 μg / mL) > Comparative Example 1 (58.96 μg / mL) > Comparative Example 2 (56.25 μg / mL) > Comparative Example 3 (20.56 μg / mL), and the total free amino acid release amount of the Example 1 sample is significantly higher than that of the Comparative Example 1 - 3 samples. There is no significant difference in the total free amino acid release amounts between the Comparative Example 2 and Comparative Example 3 samples (P < 0.05). As can also be seen from Figure 1B, at the end of simulated intestinal digestion, the order of the total amino acid release amounts of each sample from large to small is: Example 1 (914.18 μg / mL) > Comparative Example 1 (750.82 μg / mL) > Comparative Example 2 (678.61 μg / mL) > Comparative Example 3 (484.41 μg / mL), and there are significant differences in the total free amino acid release amounts of each sample (P < 0.05). As can be seen from Figure 1C, at the end of simulated gastric digestion, compared with the Example 1, Comparative Example 1 - 2 samples, the Comparative Example 3 sample directly prepared from soybeans and brown rice did not release tryptophan, arginine, and glutamine. And as can be seen from Figure 1D, at the end of the simulated intestinal digestion process, the essential free amino acids with the highest release amounts in each sample are leucine, lysine, and phenylalanine, and the non-essential free amino acids with the highest release amounts are arginine, tyrosine, and glutamine. The above results indicate that there are differences in the protein digestion characteristics of each sample, and among them, the plant milk products prepared from germinated soybeans and fermented brown rice are more easily digested, absorbed, and utilized by the gastrointestinal tract. ③ Determination of molecular weight distribution Method: The high performance liquid gel permeation chromatography (Gel Permeation Chromatography, GPC) was used to determine the protein molecular weight distribution of the samples of each scheme at the digestion zero point (G0), gastric digestion end point (G120), and intestinal digestion end point (I180). Chromatographic column: TSKgel UP-SW2000 (300 mm × 4.6 mm, 2 μm); Mobile phase: Acetonitrile: Water: Trifluoroacetic acid = 20:80:0.1 (by volume); Flow rate: 0.3 mL / min; Column temperature: 25 °C; Injection volume: 20 μL; Detector: UV detector; Detection wavelength: 220 nm. The sample solution was filtered through a 0.22-μm pore size polytetrafluoroethylene filter membrane and then subjected to gel filtration on the machine. The relative molecular mass standard curve was drawn using solutions of glycine-glycine-glycine (189 Da), glycine-glycine-tyrosine-arginine (451 Da), bacitracin (1423 Da), insulin (5778 Da), and cytochrome C (12384 Da) prepared at 1 mg / mL. Results: As can be seen from Figure 2, at the zero time point of digestion and at the end of gastric digestion, there was little difference in the protein molecular weight distribution between Example 1 and Comparative Examples 1 to 3; at the end of intestinal digestion, compared with Example 1, the proportion of small molecule protein components (<500 Da) in the samples obtained from Comparative Examples 1 to 3 was significantly lower, while the proportion of protein components with a molecular weight >5000 Da increased. The higher the proportion of small molecule protein components, the more thoroughly the plant protein is digested. The above results indicate that compared with plant milk prepared from ordinary soybeans or / and brown rice, the plant milk product prepared from germinated soybeans and fermented brown rice is more easily decomposed in the gastrointestinal tract of the body, thereby promoting the absorption and utilization of protein by the body. ④ Particle size analysis Method: The particle size distribution of samples at the zero time point of digestion (G0), 60 min of gastric digestion (G60), 120 min of gastric digestion (G120), 60 min of intestinal digestion (I60), and 180 min of intestinal digestion (I180) was measured using a Microtrac S3500 laser particle size analyzer. The specific parameters were: temperature 25 °C, refractive index 1.33. Results: As can be seen from Figures 3A to 3C, compared with the sample of Example 1, there were obvious differences in the particle size changes of the samples of Comparative Example 1 and Comparative Example 3 after gastrointestinal digestion. Among them, the particle size of the sample of Example 1 decreased after gastric digestion and increased after intestinal digestion; while the particle size of the samples of Comparative Example 1 and Comparative Example 3 increased after gastric digestion and decreased after intestinal digestion. Industrial applicability The use of the plant milk provided by the present invention can be widely applied in the fields of food or health food, etc.

Claims

1. Use of vegetable milk in improving the bioavailability of vegetable protein, characterized in that: The preparation method of the plant milk comprises: Steps for preparing sprouted beans: Prepare sprouted beans using beans; Fermented rice preparation step: using rice to prepare fermented rice; and Slurry processing step: using the germinated beans and the fermented rice to prepare slurry, thereby obtaining the plant milk; Furthermore, the solid content of the vegetable milk is 10 to 15% by mass.

2. The use according to claim 1, characterized in that The beans include any one or more of soybeans, peas, kidney beans, mung beans, cowpeas, sword beans, lentils, chickpeas and pigeon peas.

3. The use according to claim 1 or 2, characterized in that The rice includes any one or more of polished round-grained rice, indica rice and glutinous rice.

4. The use according to any one of claims 1 to 3, characterized in that The rice is brown rice.

5. The use according to any one of claims 1 to 4, characterized in that: The method of improving the bioavailability of the plant protein includes any one or more of the following: increasing the amount of free amino acids released when the plant protein is digested in the organism, and reducing the molecular weight of the plant protein after digestion in the organism.

6. The use according to claim 5, characterized in that The increasing the amount of free amino acids released when the plant protein is digested in the organism includes increasing the amount of free amino acids released when the plant protein is digested in the stomach and / or intestine.

7. The use according to claim 5 or 6, characterized in that The reducing the molecular weight of the plant protein after digestion in the organism includes increasing the number of plant protein molecules with a molecular weight less than 500Da after intestinal digestion and / or reducing the number of plant protein molecules with a molecular weight greater than 5000Da after intestinal digestion.

8. Use of a vegetable milk in preparing an edible product that helps to improve the bioavailability of vegetable protein, characterized in that: The vegetable milk is the vegetable milk defined in any one of claims 1 to 7.

9. The use according to claim 8, characterized in that The method of improving the bioavailability of the plant protein includes any one or more of the following: increasing the amount of free amino acids released when the plant protein is digested in the organism, and reducing the molecular weight of the plant protein after digestion in the organism.

10. The use according to claim 8 or 9, characterized in that The content of the plant milk is 1 to 90% by mass based on the total mass of the edible product.

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