Soybean fermented yoghurt drink with improved flavor and preparation method of soybean fermented yoghurt drink

Abstract

The invention discloses a flavor-improved soybean fermented yoghurt drink and a preparation method thereof, the flavor-improved soybean fermented yoghurt drink comprises a soybean yoghurt blank and soybean yoghurt drink ingredients, the soybean yoghurt blank is prepared by fermenting a yoghurt fermentation substrate and yoghurt fermentation compound bacteria powder, the yogurt fermentation substrate is prepared from the following raw materials: 5 to 10 percent of cured soybean meal, 3 to 10 percent of white granulated sugar, 3 to 10 percent of coconut milk, 3 to 5 percent of maltodextrin, 0.3 to 0.5 percent of starch, 0.1 to 0.3 percent of pectin, 0.02 to 0.05 percent of gellan gum, 0.02 to 0.05 percent of gamma cyclodextrin, 0.1 to 1.0 percent of mono / diglycerol fatty acid ester, 0.3 to 1.0 percent of sodium citrate, 0.3 to 1.0 percent of sodium bicarbonate and the balance of water. According to the flavor-improved soybean fermented yoghurt drink, introduction of extra peculiar smell is avoided, no obvious peculiar smell exists, the adding amount of gamma cyclodextrin is only 0.02-0.05%, the price is low, conventional equipment is used in the process, high investment is not needed, and industrialization is facilitated.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a flavor-enhanced fermented soybean yogurt drink and its preparation method. Background Technology

[0002] Soybean, an annual herbaceous plant belonging to the genus *Glycine* of the legume family, is a highly representative native crop in my country, with its cultivation history dating back to the Shang and Zhou dynasties. In my country, the soybean planting area reaches 9.33 million hectares, with the three northeastern provinces, boasting a climate advantage of over 28℃ of accumulated temperature per year (≥10℃), contributing 52% of the national soybean production.

[0003] Against the backdrop of a continuously rising annual growth rate in the plant-based food market, soybeans are ushering in new development opportunities due to their rich nutritional advantages. Soybeans are one of the few plant protein sources containing a complete spectrum of essential amino acids, making them irreplaceable in the field of animal protein substitution. From a nutritional perspective, every 100 grams of dried soybeans contains 38.2 grams of protein, and its lysine content effectively compensates for the deficiencies in grain proteins. Soybeans are also rich in soy isoflavones, lecithin, and other beneficial nutrients.

[0004] However, due to the cellulose coating in the cell wall, the digestibility of protein in whole soybeans is only 65.3%. After processing into soy products such as soy milk, tofu, or yogurt, the protein absorption rate significantly improves. Taking soy yogurt as an example, fermentation with Lactobacillus plantarum not only breaks down large protein molecules into smaller peptides containing 2-5 amino acids, but also increases the conversion rate of isoflavone aglycones by 3 times, while effectively avoiding lactose intolerance issues, making it a product with huge potential in the health food market.

[0005] However, flavor defects have become a major bottleneck in the industrialization of soy yogurt. The beany taste inherent in soybeans, as well as the fermented taste produced during yogurt fermentation, severely affect the flavor and texture of soy yogurt, resulting in a limited number of fermented soy yogurt products on the market and greatly hindering the development and promotion of soy yogurt products.

[0006] In existing technologies, the main solutions to the fermented and beany taste problems in soy yogurt are as follows: First, using polyphenols to inhibit the formation of off-flavor substances, but this method may introduce additional flavors, affecting the taste of soy yogurt; second, using active enzymes to promote further decomposition of off-flavor substances, however, active enzyme technology is costly, and expensive liquid enzyme preparations can only be used once after being added to yogurt and cannot be recycled, and the byproducts of off-flavor decomposition may also produce new off-flavors; third, fermentation by screening strains that produce fewer off-flavors, but strain cultivation is time-consuming, screening is difficult, and the operation is complex and cumbersome. Therefore, there is an urgent need for a technical solution that can effectively improve the flavor of soy yogurt, is low-cost, and is easy to operate. Summary of the Invention

[0007] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a flavor-enhanced fermented soybean yogurt drink and its preparation method, which effectively masks the beany and fermented taste of soybean yogurt, improves the product flavor, and reduces production costs while simplifying the operation process.

[0008] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a flavor-improved fermented soybean yogurt drink, comprising soybean yogurt germ and soybean yogurt beverage ingredients, specifically composed as follows: Soybean yogurt starter: made from yogurt fermentation substrate and yogurt fermentation compound bacteria powder.

[0009] Yogurt fermentation substrate (by weight percentage): 5-10% cooked soybean flour, 3-10% white sugar, 3-10% coconut milk, 3-5% maltodextrin, 0.3-0.5% starch, 0.1-0.3% pectin, 0.02-0.05% gellan gum, 0.02-0.05% gamma-cyclodextrin, 0.1-1.0% mono- and diglycerides of fatty acids, 0.3-1.0% sodium citrate, 0.3-1.0% sodium bicarbonate, with the balance being water.

[0010] Yogurt fermentation compound starter culture powder (by weight percentage): Streptococcus thermophilus 50%, Lactobacillus plantarum 50%.

[0011] Soy yogurt beverage (by weight percentage): 70-80% soybean yogurt germ, 3-5% white sugar, 3-5% fructose syrup, and the remainder is water; depending on flavor requirements, citric acid, malic acid, lactic acid, sweeteners, edible salt, and other auxiliary ingredients may be added.

[0012] A method for preparing a flavor-enhanced fermented soybean yogurt beverage includes the preparation of soybean yogurt germ and the preparation of the soybean yogurt beverage, with the following specific steps: Preparation of soybean yogurt starter; Preparation of yogurt fermentation substrate: In a shearing and mixing tank, add 20-30% by weight of 85℃ hot water, then add 5-10% of cooked soybean powder, 3-10% of white sugar, 0.3-1.0% of sodium citrate, and 0.3-1.0% of sodium bicarbonate. After shearing for 5-10 minutes, heat to 75±5℃ to fully dissolve the material, and then pump the material to a high-pressure homogenizer.

[0013] The above materials are homogenized in a high-pressure homogenizer. The homogenization pressure is set to 50 bar for low pressure and 300 bar for high pressure. After the process is completed, the materials are pumped back to the shearing and mixing tank.

[0014] In the shearing mixing tank, add 20-30% by weight of 85℃ hot water, followed by 3-10% coconut milk, 3-5% maltodextrin, 0.3-0.5% starch, 0.1-0.3% pectin, 0.02-0.05% gellan gum, 0.01-0.05% γ-cyclodextrin, and 0.1-1.0% mono- and diglycerides of fatty acids. After shearing for 5-10 minutes, heat to 75±5℃ to fully dissolve the materials, and then pump the materials to a high-pressure homogenizer.

[0015] The material is homogenized again in a high-pressure homogenizer. The homogenization pressure remains at 50 bar for low pressure and 300 bar for high pressure. After processing, the material is pumped back to the shearing and mixing tank.

[0016] In the shearing and mixing tank, water is added to the material to make up the volume, and shearing is started for 3-5 minutes. After the physicochemical indicators of the material are qualified, the material is pumped to the UHT sterilizer.

[0017] In the UHT sterilizer, the material is sterilized at 130℃ for 20-60 seconds. After sterilization, the material is pumped to the cooling tank.

[0018] In a cooling tank, the material is cooled to 40-45°C to obtain the yogurt fermentation substrate, which is then pumped to a fermentation tank for later use.

[0019] Fermentation process: Inoculate the yogurt fermentation substrate with 0.005-0.010% of yogurt fermentation compound starter culture powder. After inoculation, turn on the stirrer for 5-10 minutes to ensure the starter culture powder and substrate are thoroughly mixed. Then stop stirring and maintain the temperature inside the fermentation tank at 42±2℃ for 6-8 hours. During fermentation, stop fermentation when the total acid (calculated as lactic acid) reaches 0.3-0.5g / 100ml and the pH value is within the range of 4.3-5.0, thus obtaining soybean yogurt starter.

[0020] Preparation of soy yogurt beverage: In a mixing jar, add 5-8% by weight of 85℃ hot water, then add 3-5% white sugar and 3-5% fructose syrup. Stir for 5-10 minutes, then heat to 75±5℃ to fully dissolve the sugar.

[0021] Add 75-90% of soybean yogurt starter to the mixing tank. If flavor is desired, citric acid, malic acid and other auxiliary materials can be added at the same time. After stirring for 5-10 minutes, heat to 75±5℃, add water to the material to make up the volume, and after the physicochemical indicators are qualified, the material is pumped to a high-pressure homogenizer.

[0022] The material is homogenized in a high-pressure homogenizer at a pressure of 50 bar for low pressure and 300 bar for high pressure. After processing, the material is pumped to a UHT sterilizer.

[0023] In the UHT sterilizer, the material is sterilized at 130℃ for 20-60 seconds, and then pumped to the cooling tank.

[0024] The material is cooled to 40-45°C in a cooling tank, and then filled to obtain a soybean yogurt beverage.

[0025] (III) Beneficial Effects Compared with the prior art, the present invention provides a flavor-improved fermented soybean yogurt drink and its preparation method, which has the following beneficial effects: 1. This flavor-improved fermented soybean yogurt drink and its preparation method utilizes the addition of γ-cyclodextrin. By taking advantage of its hydrophobic inner cavity and hydrophilic outer wall molecular structure, it precisely captures small molecules of beany and fermented flavors. Combined with high-pressure homogenization, it forms a stable inclusion complex, avoiding the introduction of additional off-flavors. There is no obvious off-flavor. Moreover, the amount of γ-cyclodextrin added is only 0.02-0.05%, which is inexpensive. The process uses conventional equipment and does not require high investment, which is conducive to industrialization.

[0026] 2. This flavor-improved fermented soybean yogurt drink and its preparation method use cooked soybean flour as raw material to retain complete essential amino acids, soy isoflavones and other nutrients; the compound bacteria fermentation breaks down the protein into small molecule peptides, improving the digestibility and absorption rate, increasing the conversion rate of isoflavone aglycones by 3 times, and also avoiding lactose intolerance. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0028] I. Composition of Soybean Yogurt Germ Ingredients (a) Yogurt fermentation substrate The ingredients are: 5% cooked soybean flour, 3% white sugar, 3% coconut milk, 3% maltodextrin, 0.3% starch, 0.1% pectin, 0.02% gellan gum, 0.01% γ-cyclodextrin, 0.1% mono- and diglyceride fatty acid esters, 0.3% sodium citrate, 0.3% sodium bicarbonate, and the balance being water (including 85℃ hot water added during preparation and subsequent volume adjustment, all meeting food processing water standards). Specifically, the cooked soybean flour must have a cooking degree of ≥90%, the coconut milk fat content 8-10%, the maltodextrin DE value 10-15, the pectin must be high-ester pectin, the gellan gum must be low-acyl gellan gum, the γ-cyclodextrin purity must be ≥99%, the mono- and diglyceride fatty acid ester HLB value 3.8-4.5, and the white sugar purity must be ≥99.5%.

[0029] (ii) Yogurt fermentation compound starter culture powder It is composed of Streptococcus thermophilus and Lactobacillus plantarum, each accounting for 50% by mass, and the viable count of each is ≥1×10¹. 0 CFU / g; The inoculum amount of this compound starter culture in the yogurt fermentation substrate is 0.005% (based on the total mass of the yogurt fermentation substrate).

[0030] II. Ingredients of Soy Yogurt Beverage The mixture consists of 70% soybean yogurt starter (made from the above-mentioned yogurt fermentation substrate inoculated with compound bacteria powder), 3% white sugar (purity ≥99.5%), 3% fructose syrup (fructose content 42%, glucose content 53%), and the remainder is water (including 85℃ hot water added during the preparation process and subsequent volume adjustment water, which meets the standards for water used in food processing); depending on flavor requirements, 0.1% citric acid (food grade, used to adjust the pH to 4.0-4.2) can be added as an auxiliary material.

[0031] The soybean fermented yogurt drink prepared in this embodiment uses the following steps, with each ingredient configured according to a mass percentage: 1. Preparation of soybean yogurt starter (1) Preparation of yogurt fermentation substrate Step 1: Initial material mixing and pretreatment In the shearing and mixing tank, first add 20% by weight of 85℃ hot water (the water temperature must be stable to avoid fluctuations affecting the material's dissolution efficiency). Then, add 5% of cooked soybean powder (cooking degree must reach over 90% to ensure easy protein dissolution and no raw bean taste), 3% of white sugar, 0.3% of sodium citrate (to adjust the system pH and assist subsequent fermentation), and 0.3% of sodium bicarbonate (to neutralize some acidic substances and improve the basic taste). Turn on the shearing device and shear at 3000 rpm for 5 minutes. During this time, the material temperature is raised to 70℃ (meeting the process requirement of 75±5℃) through the tank wall heating jacket. Continue stirring until the material is completely dissolved and there are no obvious particles or sediment. Then, the material is pumped to a high-pressure homogenizer through a pipeline.

[0032] Step 2: First high-pressure homogenization Start the high-pressure homogenizer and set the homogenization pressure to 50 bar for low pressure and 300 bar for high pressure (the pressure needs to be increased gradually to avoid sudden high pressure causing equipment shock). Homogenize the above mixture twice to ensure that the particle size is controlled within 1-5 μm. After homogenization, pump the material back to the shearing and mixing tank through the reflux pipe.

[0033] Step 3: Subsequent material addition and mixing Add 20% of 85℃ hot water to the shearing mixing tank again, then add 3% coconut milk (pure coconut milk with a fat content of 8-10% to enhance the milky flavor), 3% maltodextrin (maltodextrin with a DE value of 10-15 to enhance system stability), 0.3% starch (corn starch to aid thickening), 0.1% pectin (high-ester pectin to improve the product's water-holding capacity), 0.02% gellan gum (low-acyl gellan gum, which synergistically enhances stability with other colloids), 0.01% γ-cyclodextrin (food grade, purity ≥99%, to ensure odor encapsulation), and 0.1% mono- and diglyceride fatty acid esters (hydrophilic emulsifier, HLB value 3.8-4.5, to improve oil-water mixing). Restart the shearing device and shear at 3000 rpm for 5 minutes, then heat to 70℃ to ensure all materials are completely dissolved and form a homogeneous mixture. Finally, pump the mixture to a high-pressure homogenizer.

[0034] Step 4: Second high-pressure homogenization and volume determination The mixture was homogenized a second time according to the parameters of 50 bar for low pressure and 300 bar for high pressure. After homogenization, it was pumped back to the shear mixing tank. Room temperature purified water was added to the tank until the total mass percentage reached 100%, completing the volume adjustment. The shear device was turned on, and the mixture was stirred at 2000 rpm for 3 minutes to ensure more uniform mixing. Samples were taken for testing of physicochemical indicators: solid content ≥15%, pH value 6.0-6.5. After confirming compliance, the material was pumped to the UHT sterilizer.

[0035] Step 5: UHT sterilization and cooling The UHT sterilizer is set to a temperature of 130℃ and a sterilization time of 20 seconds (using ultra-high temperature instantaneous sterilization to reduce nutrient loss), maintaining a stable material flow rate during the sterilization process. After sterilization, the material enters a cooling tank, where the temperature is reduced to 40℃ through cold water circulation, yielding the yogurt fermentation substrate, which is then pumped to an aseptic fermentation tank for later use.

[0036] (2) Fermentation process Inoculate the yogurt fermentation substrate in the fermentation tank with 0.005% by weight of a yogurt fermentation compound starter culture (composed of 50% Streptococcus thermophilus and 50% Lactobacillus plantarum, with a viable count ≥1×10¹). 0 (CFU / g). Turn on the fermenter agitator and stir at 100 rpm for 5 minutes to ensure thorough mixing of the inoculum and substrate, preventing localized agglomeration of inoculum. Turn off the agitator and maintain the fermentation temperature at 40℃ (meeting the fermentation temperature requirement of 42±2℃) for 6 hours. During fermentation, take samples every hour for testing: when the total acid (calculated as lactic acid) reaches 0.3g / 100ml and the pH value is 4.3, immediately stop heating to obtain soybean yogurt embryos, which are then transferred to a low-temperature temporary storage tank (temperature 2-4℃) for later use.

[0037] 2. Preparation of Soy Yogurt Beverage (1) Sugar solution preparation and mixing In a mixing tank, add 5% (by weight) of 85°C hot water, 3% white sugar, and 3% high-fructose corn syrup (42% fructose, 53% glucose). Turn on the mixer and stir at 2500 rpm for 5 minutes. Heat to 70°C and continue stirring until the sugar is completely dissolved, forming a clear, impurity-free sugar solution. Slowly add 70% of the soybean yogurt starter (removed from the storage tank and allowed to return to room temperature before adding) to the mixing tank. If flavor adjustment is needed, add 0.1% citric acid (food grade, adjust pH to 4.0-4.2). Turn on the mixer and mix at 2000 rpm for 5 minutes. Heat to 70°C and add room-temperature purified water to bring the total volume to 100%. Sample and test the physicochemical indicators: sugar content 12-14 Brix, acidity 0.4-0.6 g / 100 ml (calculated as lactic acid). After confirming compliance, transfer to a high-pressure homogenizer.

[0038] (2) Homogenization, sterilization and filling The high-pressure homogenizer is set to a low pressure of 50 bar and a high pressure of 300 bar to homogenize the mixture, ensuring uniform particle size. After homogenization, the material is pumped to a UHT sterilizer and sterilized at 130℃ for 20 seconds, then cooled to 40℃ in a cooling tank. Aseptic filling equipment (filling environment cleanliness level 10,000) is used to fill the material into 200ml aseptic PET bottles, which are then screwed on and sealed (sealing pressure 0.3MPa). After filling, the product undergoes visual inspection (checking for impurities and leakage). Qualified products are flavor-improved fermented soybean yogurt drinks. Example

[0039] I. Composition of Soybean Yogurt Germ Ingredients (a) Yogurt fermentation substrate The ingredients are: 8% cooked soybean flour (cooking degree ≥90%), 7% white sugar (purity ≥99.5%), 7% coconut milk (fat content 8-10%), 4% maltodextrin (DE value 10-15), 0.4% starch (corn starch), 0.2% pectin (high ester pectin), 0.03% gellan gum (low acyl gellan gum), 0.03% γ-cyclodextrin (purity ≥99%), 0.5% mono- and diglyceride fatty acid esters (HLB value 3.8-4.5), 0.7% sodium citrate, 0.7% sodium bicarbonate, and the balance being water (including 85℃ hot water and volumetric water replenishment, meeting the standards for water used in food processing).

[0040] (ii) Yogurt fermentation compound starter culture powder Also composed of 50% each of thermophilic streptococci (live count ≥ 1 × 10¹) 0CFU / g) and Lactobacillus plantarum (live count ≥1×10¹) 0 The composition is CFU / g, and the inoculum amount in the yogurt fermentation substrate is 0.008% (based on the total mass of the yogurt fermentation substrate).

[0041] II. Ingredients of Soy Yogurt Beverage The mixture consists of 75% soybean yogurt starter (fermented from the above-mentioned yogurt fermentation substrate), 4% white sugar (purity ≥99.5%), 4% fructose syrup (fructose content 42%, glucose content 53%), and the remainder is water (including 85℃ hot water and volumetric water replenishment, meeting the standards for water used in food processing). Depending on flavor requirements, 0.15% malic acid (food grade, pH adjusted to 3.9-4.1) can be added as an auxiliary ingredient.

[0042] This embodiment adjusts the raw material ratio and process parameters based on Embodiment 1. The specific steps are as follows: 1. Preparation of soybean yogurt starter (1) Preparation of yogurt fermentation substrate Initial material mixing and pretreatment: Add 25% hot water at 85℃ to the shearing mixing tank, then add 8% cooked soybean powder, 7% white sugar, 0.7% sodium citrate, and 0.7% sodium bicarbonate. Shear at 3000r / min for 8min, heat to 75℃, dissolve, and then pump to a high-pressure homogenizer.

[0043] First high-pressure homogenization: Homogenize twice at low pressure (50 bar) and high pressure (300 bar), then return to the shearing and mixing tank.

[0044] Subsequent material addition and mixing: Add 25% hot water at 85℃, then add 7% coconut milk, 4% maltodextrin, 0.4% starch, 0.2% pectin, 0.03% gellan gum, 0.03% γ-cyclodextrin, and 0.5% mono- and diglycerides of fatty acids. Shear at 3000r / min for 8min, heat to 75℃, dissolve, and then transfer to a high-pressure homogenizer.

[0045] Second high-pressure homogenization and volume determination: After homogenization at the above pressure, the mixture is pumped back into the tank, water is added and the volume is determined, and the mixture is stirred at 2000 r / min for 4 min. The solid content is tested to be ≥16% and the pH is 6.2-6.5. After passing the test, the mixture is pumped to the UHT sterilizer.

[0046] UHT sterilization and cooling: Sterilize at 130℃ for 40 seconds, cool to 43℃ to obtain yogurt fermentation substrate, and transfer to fermentation tank.

[0047] (2) Fermentation process Inoculate with 0.008% of yogurt fermentation compound starter culture, stir at 100 rpm for 8 minutes, and ferment at a constant temperature of 42℃ for 7 hours. Stop fermentation when the total acid (calculated as lactic acid) is 0.4 g / 100 ml and the pH is 4.7, and obtain soybean yogurt germ, which is then temporarily stored at low temperature.

[0048] 2. Preparation of Soy Yogurt Beverage (1) Sugar solution preparation and mixing Add 7% hot water (85℃) to a mixing tank, then add 4% granulated sugar and 4% fructose syrup. Stir at 2500 rpm for 8 minutes, then heat to 75℃ to dissolve the sugar. Add 75% soybean yogurt starter, and optionally 0.15% malic acid (to adjust pH to 3.9-4.1). Mix at 2000 rpm for 8 minutes, then heat to 75℃ and add water to bring the volume to a final level. Test the sugar content to 13-15 Brix and the acidity to 0.5-0.7 g / 100ml. Once qualified, transfer to a high-pressure homogenizer.

[0049] (2) Homogenization, sterilization and filling Homogenize at 50 bar low pressure and 300 bar high pressure, sterilize at 130°C for 40 seconds, cool to 43°C, aseptically fill into 250ml PET bottles, and the finished product is obtained after passing the light inspection. Example

[0050] I. Composition of Soybean Yogurt Germ Ingredients (a) Yogurt fermentation substrate 10% roasted soybean flour (roasting degree ≥90%), 10% white sugar (purity ≥99.5%), 10% coconut milk (fat content 12%, enhancing flavor richness), 5% maltodextrin (DE value 10-15), 0.5% starch (corn starch), 0.3% pectin (high ester pectin), 0.05% gellan gum (low acyl gellan gum), 0.05% γ-cyclodextrin (purity 99.5%, enhancing odor encapsulation effect), 1.0% mono- and diglyceride fatty acid esters (HLB value 3.8-4.5), 1.0% sodium citrate, 1.0% sodium bicarbonate, with the balance being water (containing 85℃ hot water and volumetric water replenishment, meeting food processing water standards).

[0051] (ii) Yogurt fermentation compound starter culture powder Streptococcus thermophilus (live count ≥ 1 × 10¹) 0 CFU / g) and Lactobacillus plantarum (live count ≥1×10¹) 0 The CFU / g components were composed of 50%:50% by mass, and the inoculum amount in the yogurt fermentation substrate was 0.010% (based on the total mass of the yogurt fermentation substrate).

[0052] II. Ingredients of Soy Yogurt Beverage The mixture consists of 80% soybean yogurt starter (fermented from the above-mentioned yogurt fermentation substrate), 5% white sugar (purity ≥99.5%), 5% fructose syrup (fructose content 42%, glucose content 53%), and the remainder is water (including 85℃ hot water and volumetric water replenishment, meeting the standards for water used in food processing). Depending on flavor requirements, 0.2% lactic acid (food grade, to adjust pH to 3.8-4.0) and 0.05% edible salt (food grade, to enhance flavor profile) can be added as auxiliary ingredients.

[0053] This example illustrates the upper limit of raw material ratios and process parameters. The specific steps are as follows: 1. Preparation of soybean yogurt starter (1) Preparation of yogurt fermentation substrate Initial material mixing and pretreatment: Add 30% hot water at 85℃ to the shearing mixing tank, then add 10% cooked soybean powder, 10% white sugar, 1.0% sodium citrate, and 1.0% sodium bicarbonate. Shear at 3000r / min for 10min, and heat to 80℃ (meeting the 75±5℃ requirement) to ensure complete dissolution of the materials (no soybean powder particles precipitate). Then pump the mixture to a high-pressure homogenizer.

[0054] First high-pressure homogenization: Set low pressure to 50 bar and high pressure to 300 bar, homogenize 3 times (10 seconds each time) to ensure that the material particle size is ≤3μm, and then pump it back to the shearing and mixing tank.

[0055] Subsequent material addition and mixing: Add 30% hot water at 85℃, then add 10% coconut milk (12% fat content, to enhance richness), 5% maltodextrin, 0.5% starch, 0.3% pectin, 0.05% gellan gum, 0.05% γ-cyclodextrin (99.5% purity, to enhance odor encapsulation), and 1.0% mono- and diglycerides of fatty acids. Shear at 3000r / min for 10min, heat to 80℃, and stir until the material is a homogeneous viscous liquid without stratification. Then, pump it to a high-pressure homogenizer.

[0056] Second high-pressure homogenization and volume adjustment: Homogenize 3 times under the above pressure, then return to the shearing and mixing tank, add room temperature pure water to adjust the volume to 100%, stir at 2000 r / min for 5 min, and take samples for testing: solid content ≥18%, pH 6.3-6.6. After passing the test, transfer to the UHT sterilizer.

[0057] UHT sterilization and cooling: Sterilize at 130℃ for 60 seconds (to ensure thorough sterilization of high-solids materials), cool to 45℃ to obtain yogurt fermentation substrate, and transfer to an aseptic fermentation tank.

[0058] (2) Fermentation process Inoculate with 0.010% of yogurt fermentation compound starter culture, stir at 100 rpm for 10 minutes (extend the stirring time to ensure uniform mixing of high-concentration starter culture), and ferment at a constant temperature of 44℃ for 8 hours. Take samples every 1 hour for testing: when the total acid (calculated as lactic acid) reaches 0.5 g / 100 ml and the pH is 5.0, stop fermentation and transfer the soybean yogurt starter to a low-temperature temporary storage tank (2-4℃).

[0059] 2. Preparation of Soy Yogurt Beverage (1) Sugar solution preparation and mixing Add 8% hot water (85℃) to a mixing tank, then add 5% granulated sugar and 5% fructose syrup. Stir at 2500 rpm for 10 minutes, then heat to 80℃, ensuring the sugar is completely dissolved (sugar solution transparency ≥95%). Add 80% soy yogurt starter, and optionally add 0.2% lactic acid (to adjust pH 3.8-4.0) and 0.05% salt (to enhance flavor). Mix at 2000 rpm for 10 minutes, then heat to 80℃ and add water to bring the volume to 100%. Test the sugar content to 14-16 Brix and the acidity to 0.6-0.8 g / 100ml. After passing the tests, transfer the mixture to a high-pressure homogenizer.

[0060] (2) Homogenization, sterilization and filling Homogenize three times under low pressure (50 bar) and high pressure (300 bar) to ensure material uniformity. Sterilize at 130℃ for 60 seconds, cool to 45℃, and fill the material into 500ml aseptic paper boxes using aseptic filling equipment (filling speed 30 boxes / min). After sealing, inspect by light. Qualified products are flavor-improved fermented soybean yogurt drinks.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A flavor-enhanced fermented soybean yogurt drink, characterized in that: Including soy yogurt starter and soy yogurt beverage ingredients; The soybean yogurt starter is made from yogurt fermentation substrate and yogurt fermentation compound bacteria powder, wherein: The raw material composition of the yogurt fermentation substrate, by mass percentage, is as follows: 5-10% cooked soybean flour, 3-10% white sugar, 3-10% coconut milk, 3-5% maltodextrin, 0.3-0.5% starch, 0.1-0.3% pectin, 0.02-0.05% gellan gum, 0.02-0.05% γ-cyclodextrin, 0.1-1.0% mono- and diglyceride fatty acid esters, 0.3-1.0% sodium citrate, 0.3-1.0% sodium bicarbonate, with the balance being water; The raw material composition of the yogurt fermentation compound bacteria powder, by weight percentage, is: 50% Streptococcus thermophilus and 50% Lactobacillus plantarum, and the inoculation amount of the yogurt fermentation compound bacteria powder in the yogurt fermentation substrate is 0.005-0.010%. The ingredients of the soybean yogurt beverage, by weight percentage, consist of: 70-80% soybean yogurt germ, 3-5% white sugar, 3-5% fructose syrup, and the remainder is water; the soybean yogurt beverage ingredients may also selectively contain auxiliary materials, which are one or more of citric acid, malic acid, lactic acid, sweeteners, and edible salt.

2. The flavor-enhanced fermented soybean yogurt drink according to claim 1, characterized in that: The cooked soybean flour has a cooking degree of ≥90%; the coconut milk has a fat content of 8-12%; the maltodextrin has a DE value of 10-15; the pectin is high-ester pectin; the gellan gum is low-acyl gellan gum; the γ-cyclodextrin has a purity of ≥99%; the mono- and diglyceride fatty acid esters have an HLB value of 3.8-4.5; the white sugar has a purity of ≥99.5%; and the fructose syrup contains 42% fructose and 53% glucose.

3. The flavor-enhanced fermented soybean yogurt drink according to claim 1, characterized in that: The yogurt fermentation compound starter culture powder contains ≥1×10¹ viable bacteria of both Streptococcus thermophilus and Lactobacillus plantarum. 0 CFU / g.

4. A method for preparing a flavor-enhanced fermented soybean yogurt drink according to any one of claims 1-3, characterized in that, Includes the following steps: S1: In the shearing mixing tank, add 20-30% by weight of 85℃ hot water, then add 5-10% of cooked soybean powder, 3-10% of white sugar, 0.3-1.0% of sodium citrate, and 0.3-1.0% of sodium bicarbonate. After shearing for 5-10 minutes, heat to 75±5℃ to fully dissolve the materials. Then, pump the materials to a high-pressure homogenizer to obtain the yogurt fermentation substrate. S2: In the high-pressure homogenizer, the material obtained in step a is homogenized. The homogenization pressure is set to 50 bar for low pressure and 300 bar for high pressure. After the process is completed, the material is pumped back to the shearing and mixing tank. S3: In the shearing mixing tank, add 20-30% by weight of 85℃ hot water again, followed by 3-10% coconut milk, 3-5% maltodextrin, 0.3-0.5% starch, 0.1-0.3% pectin, 0.02-0.05% gellan gum, 0.01-0.05% γ-cyclodextrin, and 0.1-1.0% mono- and diglycerides of fatty acids. After shearing for 5-10 minutes, heat to 75±5℃ to fully dissolve the materials, and then pump the materials to a high-pressure homogenizer. S4: In the high-pressure homogenizer, the material obtained in step c is homogenized again. The homogenization pressure is 50 bar for low pressure and 300 bar for high pressure. After processing, the material is pumped back to the shearing and mixing tank. S5: In the shearing and mixing tank, add water to the material to make up the volume, start shearing for 3-5 minutes, and after the physicochemical indicators of the material are qualified, the material is pumped to the UHT sterilizer. In the UHT sterilizer, the material is sterilized at 130℃ for 20-60 seconds. After sterilization, the material is pumped to the cooling tank and cooled to 40-45℃ to obtain the yogurt fermentation substrate. S6: Inoculate 0.005-0.010% of yogurt fermentation compound bacteria powder into the yogurt fermentation substrate obtained in S1. After inoculation, turn on the stirrer for 5-10 minutes to fully mix the bacteria powder with the substrate. After stopping the stirrer, maintain the temperature at 42±2℃ and ferment for 6-8 hours. When the total acid of the material reaches 0.3-0.5g / 100ml and the pH value is in the range of 4.3-5.0, stop the fermentation to obtain soybean yogurt embryo. S7: In a mixing jar, add 5-8% by weight of 85℃ hot water, then add 3-5% white sugar and 3-5% fructose syrup. Stir for 5-10 minutes, then heat to 75±5℃ to fully dissolve the sugar. S8: Add 75-90% of soybean yogurt starter to the mixing tank. If auxiliary materials are required, add them at the same time. After stirring for 5-10 minutes, heat to 75±5℃, add water to the material to make up the volume, and after the physicochemical indicators are qualified, pump the material to the high pressure homogenizer. S9: In a high-pressure homogenizer, the material obtained in S1 is homogenized at a low pressure of 50 bar and a high pressure of 300 bar. After processing, the material is pumped to a UHT sterilizer. In the UHT sterilizer, the material is sterilized at 130°C for 20-60 seconds. After sterilization, the material is pumped to a cooling tank and cooled to 40-45°C. The cooled material is then bottled to obtain a flavor-improved fermented soybean yogurt drink.

5. The method for preparing a flavor-enhanced fermented soybean yogurt drink according to claim 4, characterized in that: After fermentation in step S3, the soybean yogurt starter needs to be transferred to a low-temperature temporary storage tank at a temperature of 2-4℃ for later use; in step S8, the added soybean yogurt starter needs to be removed from the low-temperature temporary storage tank and restored to room temperature.

6. The method for preparing a flavor-enhanced fermented soybean yogurt drink according to claim 4, characterized in that: In step S5, the qualified physicochemical indicators are: solid content of material ≥15% and pH value 6.0-6.5; in step S8, the qualified physicochemical indicators are: sugar content of material 12-16 Brix and acidity of material 0.4-0.8g / 100ml (calculated as lactic acid).

7. The method for preparing a flavor-enhanced fermented soybean yogurt drink according to claim 4, characterized in that: In S9, aseptic filling equipment is used for filling, the cleanliness of the filling environment is Class 10,000, and after filling, the product needs to be inspected by light to remove products containing impurities or leaking liquid.