Pure grain fermented active probiotic beverage and preparation method thereof

Abstract

The invention provides a pure grain fermented active probiotic beverage and a preparation method thereof. The acidity of the pure grain fermented active probiotic beverage is 45-55 DEG T, the centrifugal precipitation rate is 1.4-2%, and the viable count is not less than 1 * 10 < 8 > CFU / ml. The pure grain fermented active probiotic beverage has the advantages of good flavor, good taste, pleasant color and luster, high stability, light aftertaste, high viable count and the like.

Description

Technical Field

[0001] The invention relates to a probiotic drink, in particular to a pure grain fermentation active probiotic drink and a preparation method thereof, belonging to the field of food. Background Art

[0002] Probiotics are a type of active microorganisms that can regulate gastrointestinal homeostasis, nutrient digestion and absorption, and body energy balance.

[0003] Cereals have the advantages of low fat content, high protein content, high dietary fiber content, and rich in vitamins, calcium, iron, zinc and other minerals. They meet people's current demand for healthy diets. Pure grain foods have attracted the attention of many people because of their good nutritional and health functions, and have broad development space in the market.

[0004] Cereals are high-quality carriers for probiotic fermentation. Under suitable conditions, probiotics can transform the ingredients in cereals into products needed by humans through specific metabolic pathways, thereby improving the nutritional value of products and enriching the diversity and probiotic functions of products. For example, fermented soybean meal and cereal probiotic drinks are products obtained by developing cereals through probiotic fermentation. Among them, cereal probiotic drinks are popular among consumers because of their convenience, rich nutrition and health benefits.

[0005] However, existing cereal probiotic drinks still have problems such as poor flavor, severe aftertaste, unstable live bacteria count, and easy precipitation. Summary of the invention

[0006] The invention provides a pure grain fermented active probiotic beverage, which has moderate acidity, light after-acidity, low centrifugal sedimentation rate, high product stability, and the number of live bacteria is stably maintained at a high level.

[0007] The present invention also provides a method for preparing a pure grain fermented active probiotic beverage, which is beneficial to the control of post-acidity of the product and the maintenance of a high number of viable bacteria, and has the effect of improving the stability of the product. The pure grain fermented active probiotic beverage prepared by the method has the advantages of light post-acidity, high number of viable bacteria, low centrifugal sedimentation rate, and high product stability.

[0008] The present invention provides a pure grain fermentation active probiotic beverage, wherein the acidity of the pure grain fermentation active probiotic beverage is 45°T-55°T, the centrifugal sedimentation rate is 1.4%-2%, and the number of live bacteria is not less than 1×10 8 CFU / ml.

[0009] The pure grain fermented active probiotic beverage as described above, wherein the pure grain fermented active probiotic beverage is prepared by a method comprising at least the following processes:

[0010] Using amylase to enzymatically hydrolyze the aqueous solution of the raw materials including the grains to obtain an enzymatic hydrolyzate, and after subjecting the enzymatic hydrolyzate to ultra-high pressure sterilization and / or pulse electric field sterilization, fermentation is performed to obtain the pure grain fermented active probiotic beverage;

[0011] Among them, the pressure of ultra-high pressure sterilization treatment is 800-900Mpa, and the pressure holding time is 2-5min; the pulse electric field intensity of pulse electric field sterilization treatment is 5-10kV / cm, and the frequency is 15-25kHz;

[0012] The sterilization is terminated when the colony lethality of the sterilization system after the sterilization treatment is not less than 99%.

[0013] The pure grain fermented active probiotic beverage as described above, wherein the raw materials of the probiotic beverage include, by weight percentage: 10% to 20% grains, 0.02% to 0.08% amylase, 0.001% to 0.05% probiotic fermentation agent, and the remainder is water and / or food adjuvant;

[0014] The specific activity of the amylase is 30000-100000 U / g; the number of viable bacteria in the probiotic fermentation agent is 1.0×10 9 -1.0×10 11 CFU / g.

[0015] The pure grain fermented active probiotic beverage as described above, wherein the grain is at least one of highland barley, oats, buckwheat, wheat, barley, black rice, rice, corn, soybeans, and peas.

[0016] The pure grain fermented active probiotic beverage as described above, wherein the amylase is at least one of α-amylase, β-amylase, γ-amylase and isoamylase.

[0017] The pure grain fermented active probiotic beverage as described above, wherein the food adjuvant includes at least one of a sweetener, a stabilizer, dietary fiber, vitamins, minerals, β-glucan, edible flavors, and salt.

[0018] The present invention also provides a method for preparing any of the above-mentioned pure grain fermented active probiotic beverages, comprising:

[0019] 1) dissolving a first raw material including grains in water to obtain a first material;

[0020] 2) adding amylase to the first material, and stopping the enzymatic hydrolysis when the starch content of the first material is lower than 3%, to obtain a second material;

[0021] 3) performing ultrahigh pressure sterilization and / or pulse electric field sterilization on the second material to obtain a third material;

[0022] 4) adding a probiotic fermentation agent to the third material and fermenting the material, and terminating the fermentation when the fermentation acidity is 45°T to 55°T to obtain the pure grain fermented active probiotic beverage;

[0023] Among them, the pressure of ultra-high pressure sterilization treatment is 800-900Mpa, and the pressure holding time is 2-5min; the pulse electric field intensity of pulse electric field sterilization treatment is 5-10kV / cm, and the frequency is 15-25kHz;

[0024] The sterilization is terminated when the colony lethality of the system after the sterilization treatment is not less than 99%.

[0025] As described above, the preparation method, wherein the ultra-high pressure sterilization treatment condition is 850-875MPa, and the pressure holding time is 3-4min; the process parameters of the pulse electric field sterilization treatment are pulse electric field strength of 7.5-9kV / cm and frequency of 18-20kHz.

[0026] The preparation method as described above, wherein in step 4), after terminating the fermentation, further comprises homogenizing the fermentation system.

[0027] The preparation method as described above, wherein the homogenization condition is that the homogenization pressure is 20-30Mpa.

[0028] The pure grain fermented active probiotic beverage provided by the present invention has the nutritional characteristics of low fat content, high protein content, high dietary fiber content, rich in vitamins, calcium, iron, zinc and other minerals, etc., which meets the current people's demand for healthy diet; more importantly, the beverage has moderate acidity, light after-acidity, and a sour, sweet and refreshing taste; the centrifugal sedimentation rate is low and the product stability is good; the number of viable bacteria is not less than 1×10 8 CFU / ml, the number of live bacteria is stably maintained at a high level; the product is fluid, suitable for direct drinking and convenient to drink. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The first aspect of the present invention provides a pure grain fermentation active probiotic beverage, wherein the acidity of the pure grain fermentation active probiotic beverage is 45°T to 55°T, the centrifugal sedimentation rate is 1.4% to 2%, and the number of live bacteria is not less than 1×10 8 CFU / ml.

[0031] Acidity is an important component of the taste of pure grain fermented active probiotic beverages. Tartaric acid and lactic acid naturally produced during probiotic fermentation... these will bring acidity to the beverage. Too high or too low acidity will make the above-mentioned beverages lack a refreshing feeling. Moderate acidity can balance the various tastes of the beverages, highlight the high-quality flavor, and give the beverages a refreshing sour feeling. In addition, it can also promote appetite, strengthen the spleen and stimulate the appetite, and can improve the absorption of elements such as calcium and phosphorus, enhance liver function, and is also beneficial for the prevention and treatment of some diseases. The acidity of the pure grain fermented active probiotic beverage of the present invention is 45°T~55°T during the shelf life, the acidity is appropriate, and the after-acidity is light. The beverage shows a special taste with refreshing acidity, and people can taste the sweet and sour refreshing taste when they take it.

[0032] The cereal beverage system contains colloidal solutions formed by proteins, emulsions formed by emulsified fats, and true solutions formed by sugars, etc. The large density difference between these components is one of the main reasons for the instability of the cereal beverage system. Cereal beverages are prone to floating, stratification, precipitation and other problems after being left for a long time. Among them, precipitation is the most obvious problem. Therefore, the centrifugal sedimentation rate can generally be used to characterize the stability of cereal beverages. The centrifugal sedimentation rate refers to the percentage of the precipitate obtained after centrifuging the beverage to the total mass of the beverage. The centrifugal sedimentation rate of the pure cereal fermented active probiotic beverage of the present invention during the shelf life is 1.4%-2%, which is at a relatively low level, indicating that the beverage of the present invention has good stability during the shelf life.

[0033] The number of viable bacteria is also one of the important indicators for evaluating the quality of pure grain fermented active probiotic beverages. During the shelf life, the number of viable bacteria of a high-quality beverage should be at a high level and be able to remain stable. During the shelf life, the number of viable bacteria of the beverage of the present invention is always not less than 1×10 8 CFU / ml, high viable count and good stability.

[0034] The pure grain fermented active probiotic beverage of the present invention has the nutritional characteristics of low fat content, high protein content, high dietary fiber content, high number of live bacteria, and rich in vitamins, calcium, iron, zinc and other minerals, etc., which meets the current people's demand for healthy diet; the acidity is moderate, the after-acidity is light, and it has a sweet and sour refreshing taste; the centrifugal sedimentation rate is low and the product stability is good; it is suitable for direct drinking and is convenient to drink.

[0035] In a specific embodiment, the above-mentioned pure grain fermented active probiotic beverage is prepared by a method comprising at least the following processes:

[0036] Using amylase to enzymatically hydrolyze the aqueous solution of the raw materials including the grains to obtain an enzymatic hydrolyzate, and after subjecting the enzymatic hydrolyzate to ultra-high pressure sterilization and / or pulse electric field sterilization, fermentation is performed to obtain the above-mentioned pure grain fermented active probiotic beverage;

[0037] Among them, the pressure of ultra-high pressure sterilization treatment is 800-900Mpa, and the pressure holding time is 2-5min; the pulse electric field intensity of pulse electric field sterilization treatment is 5-10kV / cm, and the frequency is 15-25kHz;

[0038] The sterilization is terminated when the colony lethality of the sterilization system after the sterilization treatment is not less than 99%.

[0039] Amylase hydrolyzes the starch in the raw materials into soluble glucose and maltose. These products can not only serve as carbon sources for probiotic fermentation, but also help improve product stability.

[0040] Probiotic fermentation agent plays an important role in the production of pure grain fermentation active probiotic beverage of the present invention, but the probiotic fermentation agent used in the present invention is very susceptible to contamination by miscellaneous bacteria, infection by bacteriophages, and interference by antibacterial substances during the fermentation process, which reduces the fermentation acid production capacity of the strain and even causes the death of the strain. Ultra-high pressure sterilization and / or pulsed electric field sterilization are used, and the pressure of the ultra-high pressure sterilization is 800-900Mpa, and the pressure holding time is 2-5min; when the pulse electric field intensity of the pulsed electric field sterilization is 5-10kV / cm and the frequency is 15-25kHz, miscellaneous bacteria, bacteriophages, antibacterial substances, etc. in the fermentation system can be completely eliminated, avoiding the interference of these components on the probiotic fermentation, which is beneficial to increasing the fermentation speed, shortening the fermentation time, and improving the fermentation quality, so that the prepared product has the advantages of moderate acidity, refreshing sour taste, good taste, good flavor, uniform color, low centrifugal sedimentation rate, high product stability, and high number of viable bacteria.

[0041] In a specific embodiment, the raw materials of the above-mentioned probiotic beverage include, by weight percentage: 10% to 20% of cereals, 0.02% to 0.08% of amylase, 0.001% to 0.05% of probiotic fermentation agent, and the remainder is water and / or food additives;

[0042] The specific activity of the above-mentioned amylase is 30000-100000U / g; the number of viable bacteria in the probiotic fermentation agent is 1.0×10 9 -1.0×10 11 CFU / g.

[0043] As an important part of people's daily diet, cereals have the nutritional characteristics of low fat content, high protein content, high dietary fiber content, and rich in vitamins, calcium, iron, zinc and other minerals. They meet people's current demand for a healthy diet. They are also high-quality carriers for probiotic fermentation and are suitable for making probiotic drinks.

[0044] The present invention does not specifically limit the type of amylase, but the quality and specific activity of the amylase should meet the above requirements to ensure the expected enzymatic hydrolysis effect. It can be understood that the activity of the amylase in the raw materials of the above-mentioned probiotic beverage is equal to the product of the quality of the amylase and the specific activity.

[0045] The present invention does not specifically limit the type of probiotic fermentation agent, and at least one of Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus paracasei, Bifidobacterium, Bifidobacterium longum, Bifidobacterium animalis, Leuconostoc mesenteroides, Lactobacillus rhamnosus, and Lactobacillus reuteri can be used.

[0046] When the raw materials of the probiotic beverage include 10% to 20% by weight of cereals, 0.02% to 0.08% of amylase, 0.001% to 0.05% of probiotic fermentation agent, and the balance of water and / or food additives, the specific activity of the amylase is 30,000 to 100,000 U / g; the number of viable bacteria in the probiotic fermentation agent is 1.0×10 9 -1.0×10 11 CFU / g, the prepared beverage is rich in nutrition, has good taste and flavor, uniform color, suitable for direct drinking, sour and refreshing, high stability, and the number of viable bacteria remains stable during the shelf life and is not less than 1×10 8 CFU / ml.

[0047] The present invention does not limit the types of cereals, and at least one of highland barley, oats, buckwheat, wheat, barley, black rice, rice, corn, soybeans, and peas can be used to add different tastes, nutrition, flavors, and colors to the product.

[0048] Likewise, the amylase preparation of the present invention may use at least one of α-amylase, β-amylase, γ-amylase, and isoamylase.

[0049] The above-mentioned food adjuvant may include at least one of a sweetener, a stabilizer, dietary fiber, vitamins, minerals, β-glucan, edible flavors, and salt, which can give the product more abundant nutrition, further improve the product flavor, and increase the variety of products. The present invention does not specifically limit the amount of the above-mentioned food adjuvant added, and it can be determined according to the conventional amount used in the art.

[0050] The above-mentioned sweeteners include at least one of sucralose, acesulfame potassium, steviol glycosides, xylitol, maltitol, erythritol and mogroside. The specific amount of the above-mentioned sweeteners added is determined after matching calculation based on the target sweetness of the product and the sweetness that the sweetener can provide. The amount added should comply with the requirements of the corresponding national standards.

[0051] The stabilizer includes at least one of pectin, carboxymethyl cellulose, gellan gum, propylene glycol alginate, soluble soybean polysaccharide, citrus fiber and xanthan gum.

[0052] The present invention also provides a method for preparing any of the above pure grain fermented active probiotic beverages, comprising:

[0053] 1) dissolving a first raw material including grains in water to obtain a first material;

[0054] 2) adding amylase to the first material, and stopping the enzymatic hydrolysis when the starch content of the first material is lower than 3%, to obtain a second material;

[0055] 3) performing ultrahigh pressure sterilization and / or pulse electric field sterilization on the second material to obtain a third material;

[0056] 4) adding the probiotic fermentation agent to the third material and fermenting, and terminating the fermentation when the fermentation acidity is 45°T to 55°T to obtain the pure grain fermented active probiotic beverage;

[0057] Among them, the pressure of ultra-high pressure sterilization treatment is 800-900Mpa, and the pressure holding time is 2-5min; the pulse electric field intensity of pulse electric field sterilization treatment is 5-10kV / cm, and the frequency is 15-25kHz;

[0058] The sterilization is terminated when the colony lethality of the system after the sterilization treatment is not less than 99%.

[0059] It can be understood that in order to make the first raw material dissolve evenly in water, the first raw material including cereals can be added to water in powder form at 40°C to 45°C and continuously stirred. Generally, the continuous stirring time can be 20-30 minutes. At this time, the molecular movement in the first raw material is more intense, so the first raw material can be evenly dissolved. The present invention does not impose any special limitation on the particle size of the above-mentioned powder, as long as the state of the first material obtained in step 1) remains stable.

[0060] The enzymatic hydrolysis of the starch in the first material using amylase can refine the particles in the first material and decompose some insoluble starch into soluble sugars, such as maltose, glucose, etc. These soluble sugars can provide a carbon source for probiotic fermentation on the one hand, and on the other hand, are conducive to reducing the centrifugal sedimentation rate of the product, thereby improving the stability of the product.

[0061] Amylase is a conventional enzyme preparation with a specific optimum temperature. For example, the optimum temperature of α-amylase is 40°C to 45°C. Therefore, in step 2), the temperature of the first material should be kept within the optimum temperature range of amylase, which is conducive to improving the enzymatic hydrolysis effect. Similarly, if the above-mentioned amylase has requirements for the optimum pH, the pH value of the first material needs to be kept within the optimum pH range of amylase.

[0062] When the starch content of the first material is lower than 3%, it means that most of the starch in the cereal raw material has been enzymatically hydrolyzed into small molecular active substances such as glucose and maltose, and the degree of enzymatic hydrolysis reaches the expected requirement, and the enzymatic hydrolysis can be terminated. At this time, the enzymatic hydrolysis time is generally 30 to 35 minutes.

[0063] The probiotic fermentation agent is one of the key factors in the fermentation of the present invention. The activity and quantity of the probiotic fermentation agent have a great influence on the acidity, flavor, stability, number of live bacteria, etc. of the product. The lactic acid-producing probiotic fermentation agent used in the present invention is very susceptible to bacteriophage infection, which reduces the acid production ability of the strain or causes its death. Miscellaneous bacteria and antibacterial substances in the fermentation system will also have a great influence on the activity of the probiotic fermentation agent.

[0064] Ultra-high pressure sterilization is to use water as a medium to apply a certain pressure to the second material in a sealed ultra-high pressure container, thereby killing almost all bacteria, molds and yeasts therein, and will not cause nutrient destruction and flavor changes like traditional high temperature sterilization. The pressure of the ultra-high pressure sterilization treatment of the present invention is 800-900Mpa, and the pressure holding time is 2-5min; under this pressure condition, the bacteria, molds, yeasts, bacteriophages and other antibacterial substances in the second material can be eliminated more thoroughly, ensuring that the growth and reproduction of the microbial fermentation agent during the fermentation process is not disturbed, accelerating the fermentation speed, significantly shortening the fermentation time, significantly improving the fermentation quality, and being conducive to maintaining a high number of viable bacteria in the product. In addition, it is also conducive to controlling the acidity of the product during the shelf life, making the product's post-acidity lighter, and also conducive to improving the stability of the product.

[0065] Pulse electric field sterilization is to sterilize food by generating an instantaneous high-voltage pulse electric field between two electrodes. Compared with high-temperature sterilization, it will not cause damage to nutrients and change in flavor. The pulse electric field intensity of the pulse electric field sterilization treatment of the present invention is 5-10kV / cm, and the frequency is 15-25kHz. Similar to ultra-high pressure sterilization, the pulse electric field sterilization treatment under the above conditions can more thoroughly eliminate the miscellaneous bacteria, bacteriophages and antibacterial substances in the second material that interfere with the fermentation of the microbial fermentation agent, thereby accelerating the fermentation speed of the microbial fermentation agent, significantly shortening the fermentation time, significantly improving the fermentation quality, and being conducive to maintaining a high number of viable bacteria in the product. In addition, it is also conducive to controlling the acidity of the product during the shelf life, making the product's post-acidity lighter, and improving the stability of the product.

[0066] When the colony lethality of the sterilization system is not less than 99%, the sterilization treatment can be terminated. At this time, the treatment time of ultra-high pressure sterilization is generally 2 to 5 minutes, and the treatment time of pulse electric field sterilization is generally 30 to 60 seconds.

[0067] In addition to sterilization, the above two sterilization technologies also inactivate amylase, that is, the two-step process of sterilization and enzyme inactivation is integrated into a one-step process, saving production costs.

[0068] In addition, it can be understood that the above two sterilization technologies, namely ultra-high pressure sterilization and pulsed electric field sterilization, can be used either one or the other, and can be used alternately at the same time, and a reasonable choice can be made according to actual production conditions.

[0069] The fermentation process of the present invention takes the fermentation end point when the fermentation acidity reaches 45°T to 55°T, and the pure grain fermented active probiotic beverage of the present invention can be prepared after the fermentation is completed.

[0070] The present invention generally adopts a one-step batching process to prepare a pure grain fermented active probiotic beverage. Compared with the existing two-step and multi-step batching processes, it has the advantages of saving process costs, shortening fermentation time, light post-acidity of the product, high stability and high number of viable bacteria.

[0071] The pure grain fermented active probiotic beverage prepared by the above method has moderate acidity, refreshing sourness, and sweet and sour taste; low centrifugal sedimentation rate, high product stability, no unacceptable stratification and precipitation, and no obvious odor; the number of live bacteria can be kept constant during the shelf life, and the number of live bacteria is not less than 1×10 8 CFU / ml; good taste, good flavor, and uniform color.

[0072] When the first raw material also includes a food adjuvant, the present invention does not limit the order of adding the food adjuvant. For example, the food adjuvant is mixed with the cereal to obtain the first raw material, and then the first raw material is dissolved. Alternatively, the food adjuvant and the cereal can be added to water in sequence for dissolution.

[0073] It is understandable that if the pure grain fermented active probiotic beverage prepared above is canned, the beverage must be cooled to below 10°C before canning and cold-canned at below 10°C. The canned beverage must be refrigerated and stored at 0-4°C. The purpose of the above low-temperature treatment is to avoid product deterioration.

[0074] Furthermore, when the conditions of the above-mentioned ultra-high pressure sterilization treatment are 850-875MPa and the pressure holding time is 3-4min; the process parameters of the pulse electric field sterilization treatment are a pulse electric field intensity of 7.5-9kV / cm and a frequency of 18-20kHz, the acidity, centrifugal sedimentation rate, number of viable bacteria, taste, flavor, color and other qualities of the product can be further optimized.

[0075] In step 4) of the above preparation method, after terminating the above fermentation, the fermentation system is further subjected to homogenization treatment to micronize and homogenize the dispersed matter in the fermentation system, which is beneficial to reducing the centrifugal sedimentation rate of the product and improving the stability of the product.

[0076] The present invention does not impose any particular limitation on the homogenization conditions. For example, the homogenization pressure may be 20-30 MPa.

[0077] Hereinafter, the pure grain fermented active probiotic beverage of the present invention and the preparation method thereof are introduced in more detail through specific examples.

[0078] The specific sources of some raw materials in the following preparation process are:

[0079] The probiotic fermentation agent is composed of Lactobacillus bulgaricus, Streptococcus thermophilus, and Lactobacillus paracasei, wherein the mass ratio of the above three in the probiotic fermentation agent is 20:50:30, and the number of live bacteria in the probiotic fermentation agent is 1.0×10 9 -1.0×10 11 CFU / g: Chr. Hansen (Beijing) Trading Co., Ltd.;

[0080] Example 1

[0081] A highland barley fermented active probiotic beverage of the present embodiment includes the following raw materials (the total amount of raw materials is calculated based on 1000 kg):

[0082] Highland barley flour 15.00kg, amylase 0.5kg, maltitol liquid 40.00kg, acesulfame potassium 0.05kg, sucralose 0.03kg, sodium carboxymethyl cellulose 2.00kg, β-glucan 5.00kg, fermentation bacteria 0.1kg, and the balance is water;

[0083] The preparation method of the above-mentioned highland barley fermented active probiotic beverage comprises the following steps:

[0084] 1) adding highland barley flour, maltitol solution, acesulfame potassium, sucralose, sodium carboxymethyl cellulose and β-glucan into water in sequence, stirring continuously at 40-45° C. for 20-30 min to obtain a first material;

[0085] 2) adding amylase to the first material, maintaining the temperature of the first material at 40-45° C., and performing enzymolysis for 30-35 minutes to obtain a second material;

[0086] 3) The second material is subjected to ultra-high pressure sterilization treatment, with an ultra-high pressure pressure of 850 MPa and a treatment time of 3 min to obtain a third material;

[0087] 4) adding a probiotic fermentation agent to the third material and fermenting the material, and terminating the fermentation when the fermentation acidity is 45°T to 55°T to obtain a fourth material;

[0088] 5) homogenizing the fourth material at a homogenization pressure of 20-30 MPa, cooling and canning the material to obtain the highland barley fermented active probiotic beverage.

[0089] Example 2

[0090] A buckwheat fermented active probiotic beverage of this embodiment includes the following raw materials (the total amount of raw materials is calculated based on 1000 kg):

[0091] Buckwheat flour 15.00kg, amylase 0.5kg, white sugar 20.00kg, stevioside 0.05kg, erythritol 0.03kg, pectin 2.00kg, polydextrose 5.00kg, fermentation bacteria 0.1kg, and the balance is water;

[0092] The method for preparing the buckwheat fermented active probiotic beverage comprises the following steps:

[0093] 1) adding buckwheat flour, white sugar, steviol glycoside, erythritol, pectin and polydextrose into water in sequence, stirring continuously for 20 to 30 minutes at 40 to 45° C. to obtain a first material;

[0094] 2) adding amylase to the first material, maintaining the temperature of the first material at 40-45° C., and performing enzymolysis for 30-35 minutes to obtain a second material;

[0095] 3) The second material is subjected to pulse electric field sterilization treatment, with a pulse electric field strength of 7 kV / cm, a frequency of 20 kHz, and a treatment time of 60 s to obtain a third material;

[0096] 4) adding a probiotic fermentation agent to the third material and fermenting the material, and terminating the fermentation when the fermentation acidity is 45°T to 55°T to obtain a fourth material;

[0097] 5) The fourth material is homogenized at a homogenization pressure of 20-30 MPa, and cooled and canned to obtain the buckwheat fermented active probiotic beverage.

[0098] Example 3

[0099] This embodiment is basically the same as embodiment 1, except that in step 3) of the preparation method, the sterilization condition is 800Mpa.

[0100] Example 4

[0101] This embodiment is basically the same as embodiment 1, except that in step 3) of the preparation method, the sterilization condition is 900Mpa.

[0102] Example 5

[0103] This embodiment is basically the same as embodiment 2, except that in step 3) of the preparation method, the sterilization condition is a pulse electric field strength of 5 kV / cm and a pulse electric field frequency of 25 kHz.

[0104] Example 6

[0105] This embodiment is basically the same as embodiment 2, except that in step 3) of the preparation method, the sterilization condition is a pulse electric field strength of 10 kV / cm and a pulse electric field frequency of 15 kHz.

[0106] Example 7

[0107] This embodiment is basically the same as embodiment 1, except that in step 3) of the preparation method, the sterilization condition is 875 MPa.

[0108] Example 8

[0109] This embodiment is basically the same as embodiment 2, except that in step 3) of the preparation method, the sterilization condition is a pulse electric field strength of 8 kV / cm.

[0110] Example 9

[0111] This embodiment is basically the same as embodiment 2, except that in step 3) of the preparation method, the sterilization condition is a pulse electric field strength of 9 kV / cm and a pulse electric field frequency of 18 kHz.

[0112] Comparative Example 1

[0113] This comparative example is basically the same as Example 1, except that conventional heat treatment sterilization is adopted in step 3) of the preparation method, and the sterilization conditions are 90-95° C. for 5 min.

[0114] Comparative Example 2

[0115] This comparative example is basically the same as Example 2, except that conventional heat treatment sterilization is used in step 3) of the preparation method, and the sterilization conditions are 90-95° C. for 5 min.

[0116] Comparative Example 3

[0117] This comparative example is basically the same as Example 1, except that in step 3) of the preparation method, the sterilization conditions are 700 MPa, 4 min.

[0118] Comparative Example 4

[0119] This comparative example is basically the same as Example 1, except that in step 3) of the preparation method, the sterilization conditions are 1000 MPa, 4 min.

[0120] Comparative Example 5

[0121] This comparative example is basically the same as Example 1, except that in step 3) of the preparation method, the sterilization condition is 850 MPa, 1 min.

[0122] Comparative Example 6

[0123] This comparative example is basically the same as Example 1, except that in step 3) of the preparation method, the sterilization conditions are 850 MPa, 6 min.

[0124] Comparative Example 7

[0125] This comparative example is basically the same as Example 2, except that in step 3) of the preparation method, the sterilization conditions are a pulse electric field strength of 4 kV / cm, a frequency of 10 kHz, and a treatment time of 60 s.

[0126] Comparative Example 8

[0127] This comparative example is basically the same as Example 2, except that in step 3) of the preparation method, the sterilization conditions are a pulse electric field strength of 12 kV / cm, a frequency of 30 kHz, and a treatment time of 60 s.

[0128] Test example

[0129] 1. The following parameters of the above embodiments and comparative examples were tested:

[0130] 1) Acidity: The acidity was tested in accordance with GB 5009.239-2016 “National Food Safety Standard - Determination of Acidity of Foods”. The specific results are shown in Table 1.

[0131] 2) Centrifugal sedimentation rate: First, take a 50mL centrifuge tube and weigh its mass, which is recorded as M0; second, weigh 30.00g (accurate to 0.01g) of sample into a 50mL centrifuge tube, weigh the mass of the centrifuge tube and the sample, which is recorded as M1; third, centrifuge the weighed sample at 20℃, 3500r / min for 15min, pour out the liquid in the centrifuge tube after the centrifugation, then invert the centrifuge tube for 10min, weigh the mass of the centrifuge tube and the sediment, which is recorded as M2; The centrifugal sedimentation rate is calculated according to the following formula:

[0132]

[0133] Each sample was measured three times in parallel and the results were averaged. The specific results are shown in Table 2.

[0134] 3) Number of viable bacteria: The number of viable bacteria was tested in accordance with GB 4789.35-2010 “National Food Safety Standard Microbiological Examination of Foods - Examination of Lactic Acid Bacteria”. The specific results are shown in Table 3.

[0135] 4) Sensory evaluation: 50 professional evaluators (male to female ratio of 1:1) were randomly selected to conduct sensory evaluation on the flavor, taste and color of the samples on the first day of the shelf life according to the sensory evaluation criteria (see Table 4). An anonymous scoring system was used, with a full score of 10 for each item, and the final score was calculated based on the average score. Then, an overall evaluation was conducted on the degree of liking the product (like, good, average), and the number of people who made the overall evaluation was counted. The specific results are shown in Table 5.

[0136] 5) Total colony count lethality: The total colony count lethality of the sterilization system was tested in accordance with GB4789.2-2016 “National Food Safety Standard Food Microbiology Test Determination of Total Colony Count”. The calculation formula for the total colony count lethality is: Total colony count lethality (%) = (total colony count of control group samples - total colony count of experimental group samples) / total colony count of control group samples × 100%. The specific results are shown in Table 6.

[0137] 6) Fermentation time: The fermentation process was timed. The specific results are shown in Table 6.

[0138] 2. Test results

[0139] Table 1 Acidity (°T)

[0140]

[0141]

[0142] The acidity results in Table 1 show that: within the shelf life, the acidity of the samples in each embodiment is between 45°T and 55°T, and the acidity is well controlled; while the samples in Comparative Examples 1-3, 5, and 7 have a high post-acidity, resulting in a poor product taste. This may be because the traditional sterilization process, the pressure of the ultra-high pressure treatment is too low or the holding time is too short, and the intensity of the high-voltage pulse electric field is too low, resulting in incomplete sterilization, causing the product to be contaminated by miscellaneous bacteria, resulting in excessive post-acidity of the product.

[0143] Table 2 Centrifugal sedimentation rate

[0144]

[0145]

[0146] The centrifugal sedimentation rate results in Table 2 show that within the shelf life, the centrifugal sedimentation rate of each embodiment and comparative example sample is maintained within 2%, indicating good stability and also proving that the ultra-high pressure treatment and pulse electric field treatment have no significant effect on the stability of the product.

[0147] Table 3 Viable bacteria count (CFU / mL)

[0148]

[0149]

[0150] The viable bacteria count results in Table 3 show that: during the shelf life, the total number of lactic acid bacteria in each embodiment sample is maintained at more than 10 to the 8th power CFU / mL; at the end of the shelf life, the total number of lactic acid bacteria in each comparative example sample is reduced to 10 to the 5th power CFU / mL, and the reason may be that the comparative example samples (Comparative Example 1, Comparative Example 2) prepared by the traditional thermal sterilization process and the comparative example samples (Comparative Example 3, Comparative Example 5, Comparative Example 7) processed by ultra-high voltage and high-voltage pulse electric field with relatively low process parameter intensity are not sufficiently sterilized in the product system of the present invention, resulting in other microorganisms such as miscellaneous bacteria not being completely killed, thereby affecting the growth and reproduction of probiotics and the survival rate during the shelf life; and the comparative example samples (Comparative Example 4, Comparative Example 6, Comparative Example 8) processed by ultra-high voltage and high-voltage pulse electric field with relatively high process parameter intensity may be due to excessive sterilization intensity. Although other microorganisms such as miscellaneous bacteria are eliminated more thoroughly, they will also have adverse effects on various nutrients in the product, especially the nutritional factors required for the growth and reproduction of probiotics, thereby affecting the production, reproduction and survival rate of probiotics.

[0151] Table 4 Sensory evaluation standards

[0152]

[0153] Table 5 Sensory evaluation results

[0154]

[0155] The sensory evaluation results in Table 5 show that the average scores of the products in each embodiment in terms of flavor, taste and color are all above 9 points, and the overall liking degree is higher; while the flavor, taste and color of the products in each comparative example are poor, and the overall liking degree is low.

[0156] Table 6 Total bacterial count lethality and fermentation time

[0157]

[0158]

[0159] The total colony count lethality and fermentation time in Table 6 show that the total colony count lethality of the base materials in each embodiment is higher than 99%, and the risk of contamination by miscellaneous bacteria in subsequent processing is low. However, the base materials of Comparative Examples 1-3, 5, and 7 have low colony count lethality due to low processing parameter intensity, and there is a risk of contamination by miscellaneous bacteria in subsequent processing. In addition, the time used for base material fermentation in Comparative Examples 4, 6, and 8 is significantly increased due to high processing parameter intensity. This may be due to the excessively high processing intensity, which has an adverse effect on the nitrogen source and / or carbon source required for product fermentation, thereby affecting the activity of the probiotics, thereby delaying the fermentation time and increasing production costs.

[0160] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pure grain fermented active probiotic beverage, characterized in that: The acidity is 45°T~55°T, the centrifugal sedimentation rate is 1.4%-2%, and the number of viable bacteria is not less than 1×10 8 CFU / ml.

2. The pure grain fermented active probiotic beverage according to claim 1, characterized in that: The pure grain fermented active probiotic beverage is prepared by a method comprising at least the following processes: Using amylase to enzymatically hydrolyze the aqueous solution of the raw materials including the grains to obtain an enzymatic hydrolyzate, and after subjecting the enzymatic hydrolyzate to ultra-high pressure sterilization and / or pulse electric field sterilization, fermentation is performed to obtain the pure grain fermented active probiotic beverage; Among them, the pressure of ultra-high pressure sterilization treatment is 800-900Mpa, and the pressure holding time is 2-5min; the pulse electric field intensity of pulse electric field sterilization treatment is 5-10kV / cm, and the frequency is 15-25kHz; The sterilization is terminated when the colony lethality of the sterilization system after the sterilization treatment is not less than 99%.

3. The pure grain fermented active probiotic beverage according to claim 2, characterized in that: The raw materials of the probiotic beverage include, by weight percentage, 10% to 20% of cereals, 0.02% to 0.08% of amylase, 0.001% to 0.05% of probiotic fermentation agent, and the remainder is water and / or food adjuvant; The specific activity of the amylase is 30000-100000 U / g; the number of viable bacteria in the probiotic fermentation agent is 1.0×10 9 -1.0×10 11 CFU / g.

4. The pure grain fermented active probiotic beverage according to claim 3, characterized in that: The cereal is at least one of highland barley, oats, buckwheat, wheat, barley, black rice, rice, corn, soybeans and peas.

5. The pure grain fermented active probiotic beverage according to claim 4, characterized in that: The amylase is at least one of α-amylase, β-amylase, γ-amylase and isoamylase.

6. The pure grain fermented active probiotic beverage according to claim 5, characterized in that: The food adjuvant comprises at least one of a sweetener, a stabilizer, dietary fiber, vitamins, minerals, β-glucan, edible flavors and salt.

7. A method for preparing a pure grain fermented active probiotic beverage according to any one of claims 1 to 6, characterized in that: include: 1) dissolving a first raw material including grains in water to obtain a first material; 2) adding amylase to the first material, and stopping the enzymatic hydrolysis when the starch content of the first material is lower than 3%, to obtain a second material; 3) performing ultrahigh pressure sterilization and / or pulse electric field sterilization on the second material to obtain a third material; 4) adding a probiotic fermentation agent to the third material and fermenting the material, and terminating the fermentation when the fermentation acidity is 45°T to 55°T to obtain the pure grain fermented active probiotic beverage; Among them, the pressure of ultra-high pressure sterilization treatment is 800-900Mpa, and the pressure holding time is 2-5min; the pulse electric field intensity of pulse electric field sterilization treatment is 5-10kV / cm, and the frequency is 15-25kHz; The sterilization is terminated when the colony lethality of the system after the sterilization treatment is not less than 99%.

8. The preparation method according to claim 7, characterized in that: The ultra-high pressure sterilization treatment conditions are 850-875MPa, and the pressure holding time is 3-4min; the process parameters of the pulse electric field sterilization treatment are pulse electric field strength of 7.5-9kV / cm and frequency of 18-20kHz.

9. The preparation method according to claim 8, characterized in that: In step 4), after terminating the fermentation, the fermentation system is further subjected to homogenization treatment.

10. The preparation method according to claim 9, characterized in that: The homogenization condition is that the homogenization pressure is 20-30Mpa.

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