Beverage based on compound fermented inulin and preparation process thereof

Abstract

The invention relates to the field of food fermentation, in particular to a beverage based on compound fermented inulin and a preparation process of the beverage. Comprising the following steps: preparing a high-nutrition inulin solution; preparing a compound bacteria solution and fermenting the inulin protein solution; and microencapsulation of the inulin fermentation liquor. According to the preparation method disclosed by the invention, the inulin fermentation liquor is embedded by preparing the sodium alginate-quinoa protein copolymer, so that the rupture deformation of the sodium alginate-protein copolymer microcapsule in the storage and transportation processes is greatly reduced, and the nutritional ingredients of the inulin fermentation liquor can be stably and slowly released; moreover, after the inulin fermentation liquor enters the stomach, the tolerance of sodium alginate to an acid environment can prevent probiotics in the inulin fermentation liquor from being greatly damaged by gastric acid, so that the components can pass through the stomach and are gradually released in intestinal tracts, the bioavailability of nutrient substances in the inulin fermentation liquor is favorably improved, and the functionality of the product is improved.

Description

Technical Field

[0001] The invention relates to the field of food fermentation, in particular to a beverage based on composite fermented inulin and a preparation process thereof. Background Art

[0002] Inulin is a natural water-soluble dietary fiber, which is widely used in regulating blood lipids, blood sugar, intestinal health, etc. It produces short-chain fatty acids through fermentation in the intestine to exert multiple physiological effects, including lowering serum cholesterol, promoting mineral absorption, improving intestinal flora, increasing intestinal motility, reducing the production of toxic metabolites, etc. These benefits of inulin make it an important functional food ingredient.

[0003] The traditional way to take in inulin is mainly through direct ingestion. Since inulin is a natural water-soluble dietary fiber, it can hardly be hydrolyzed and digested by gastric acid. It can only exert its functionality when used by beneficial microorganisms in the colon. This causes inulin to be unable to be fully fermented in the intestine due to factors such as imbalance of intestinal microbial flora and fluctuations in gastrointestinal pH, limiting its health benefits. In addition, as a dietary fiber, taking large doses directly may cause gastrointestinal discomfort, bloating and other problems, greatly affecting people's taking experience. Summary of the invention

[0004] In order to solve the above technical defects, the present invention has developed a preparation process for beverages based on composite fermented inulin, in which the inulin is first fermented in vitro, and then the inulin fermentation liquid and probiotics are encapsulated into a sustained-release wall material through microencapsulation technology, to ensure that the nutrients can be stably released in the stomach and intestines without being affected by the gastrointestinal environment. The prepared beverage based on composite fermented inulin has a high nutrient utilization rate and can give full play to the functionality of inulin.

[0005] A preparation process of a beverage based on composite fermented inulin comprises the following steps: S1: Preparation of high nutritional inulin solution The Jerusalem artichoke tubers are washed and sliced, and then put into a container, and then placed in a radio frequency dryer equipped with a hot air system for radio frequency drying, and then the radio frequency power and temperature are increased, and the hot air system is turned on for drying to obtain dried Jerusalem artichoke slices, and the dried Jerusalem artichoke slices are crushed and then degreased, and then ultrasonic extraction and microwave extraction are sequentially performed, and the supernatant is centrifuged for alcohol precipitation, and a high-nutrition inulin solution is obtained after dialysis; S2: Preparation of composite bacterial solution and fermentation of inulin protein solution Streaking culture is performed on frozen Bifidobacterium breve bacterial stock solution, Bifidobacterium longum bacterial stock solution and Streptococcus thermophilus, taking the largest single colony and placing it in a culture medium for culture, centrifuging and resuspending and rinsing, mixing the obtained three bacterial suspensions to obtain a composite bacterial suspension, concentrating the high-nutrition inulin solution, adding soy whey protein and soft white sugar, sterilizing to obtain an inulin fermentation matrix, and fermenting the inulin fermentation matrix with the composite bacterial suspension to obtain an inulin fermentation liquid; S3: Microencapsulation of inulin fermentation broth Quinoa protein and sodium alginate are blended and extruded to obtain sodium alginate-quinoa protein copolymer, inulin fermentation liquid and physiological saline are mixed and then added with sodium alginate-quinoa protein copolymer to obtain an aqueous phase, polyglycerol ricinoleate is dissolved in soybean oil to obtain an oil phase, the oil phase is added to the aqueous phase and stirred, calcium chloride is added and stirred continuously, and the mixture is allowed to stand and then centrifuged and washed to obtain sodium alginate-protein copolymer microcapsules, sodium alginate-protein copolymer sustained-release microcapsules, β-cyclodextrin and purified water are evenly mixed, and fructose syrup, mono- and di-glycerol fatty acid esters, locust bean gum and sodium carboxymethyl cellulose are added and homogenized to obtain a beverage based on composite fermented inulin.

[0006] Furthermore, the preparation of the high-nutrition inulin solution in step S1 comprises the following steps: S1.1: Wash the freshly picked Jerusalem artichoke tubers with deionized water, and then cut them into thin slices with a thickness of 4-6 mm to obtain Jerusalem artichoke slices. Place the Jerusalem artichoke slices vertically in a container with uniform ventilation holes, and then place them in the middle of the lower plate of a radio frequency dryer equipped with a hot air system. Adjust the spacing between the upper and lower plates to 7-8 cm, the radio frequency power to 600-650 W, the temperature to 45-50 ° C, and dry for 50-60 minutes. Then adjust the radio frequency power of the radio frequency dryer to 800-850 W and the temperature to 55-60 ° C. At the same time, start the hot air system, adjust the hot air power of the hot air system to 2-3 kW, and the hot air temperature to 55-60 ° C. Hot air drying the Jerusalem artichoke slices, take them out every 30-40 minutes for weighing, until the moisture content of the Jerusalem artichoke slices drops below 10%, to obtain dried Jerusalem artichoke slices; S1.2: The dried Jerusalem artichoke slices are placed in a grinder and crushed, and then passed through a 60-80 mesh sieve to obtain Jerusalem artichoke dry powder. The Jerusalem artichoke dry powder is mixed with an ethanol solution with a volume fraction of 80-85% at a solid-liquid ratio of 1: (20-25) g / mL, and then placed in an ultrasonic disperser for treatment at an ultrasonic power of 300-350 W for 25-30 minutes, and the precipitate I is collected by filtration. The precipitate I is mixed and stirred evenly with deionized water at a solid-liquid ratio of 1: (25-30) g / mL, and then added to an ultrasonic homogenizer for treatment at an ultrasonic power of 350-400 W and an ultrasonic temperature of 35-40°C for 25-30 minutes. The mixture was then added to a microwave heating apparatus and treated with a microwave power of 400-450 W for 4-5 minutes, and then placed in a centrifuge and centrifuged at a speed of 4000-4500 rpm for 10-15 minutes. The supernatant was evaporated and concentrated to 1 / 4-1 / 3 of the original volume, 4-5 times the volume of anhydrous ethanol was added and stirred evenly, and then allowed to stand at 3-4°C for 10-12 hours, and precipitate II was collected by filtration. The precipitate II was dissolved in deionized water at a solid-liquid ratio of 1: (20-25) g / mL, and added to a dialysis bag for dialyzing with deionized water for 45-48 hours, and the water was changed every 4-5 hours to obtain a high-nutrition inulin solution.

[0007] Furthermore, step S2 of preparing the composite bacterial solution and fermenting the inulin protein solution comprises the following steps: S2.1: The frozen Bifidobacterium breve bacterial stock solution, Bifidobacterium longum bacterial stock solution and Streptococcus thermophilus were placed in a clean bench for streaking, anaerobically cultured at 35-37°C for 48-50 hours, and then the largest single colonies were selected and placed in culture medium for culture for 48-50 hours, and then cultured anaerobically for 24-28 hours after one passage, and then placed in a centrifuge for centrifugation at a speed of 6000-8000 rpm for 3-4 minutes, and the supernatant was separated and discarded. The remaining suspension was resuspended and rinsed with sterile water for 2-3 times to obtain Bifidobacterium breve bacterial suspension, Bifidobacterium longum bacterial suspension and Streptococcus thermophilus suspension, and the Bifidobacterium breve bacterial suspension, Bifidobacterium longum bacterial suspension and Streptococcus thermophilus bacterial suspension were mixed and shaken evenly to obtain a composite bacterial suspension; S2.2: The high-nutrition inulin solution obtained in step S1.2 is evaporated and concentrated to 25-30% of the original volume, and then 8-10wt% of soy whey protein and 1-1.5wt% of soft white sugar are added, stirred evenly and sterilized at 121-125°C for 10-15 minutes, and sterile water is added to keep the volume unchanged to obtain an inulin fermentation matrix, and the composite bacterial liquid is inoculated into the inulin fermentation matrix under sterile conditions, and fermented at a constant temperature of 37-37.5°C for 20-25 hours to obtain an inulin fermentation liquid.

[0008] Furthermore, step S3 of microencapsulating the inulin fermentation broth comprises the following steps: S3.1: placing quinoa protein and sodium alginate in a mixer at a mass ratio of 1:(6-8) and fully mixing them, and then adding them into a twin-screw extruder, controlling the moisture content of the mixture to be 35-40%, adjusting the screw speed to 140-160rpm, and extruding at a temperature of 120-125°C, and then drying at 40-45°C to obtain a sodium alginate-quinoa protein copolymer; S3.2: Mix inulin fermentation broth and physiological saline in a volume ratio of 1: (3-5), then add 6-8wt% sodium alginate-quinoa protein copolymer, stir at a stirring speed of 200-250rpm for 15-20 minutes to obtain an aqueous phase, add 1.5-2wt% polyglycerol ricinoleate to soybean oil, stir until the polyglycerol ricinoleate is completely dissolved, and obtain an oil phase, measure the aqueous phase and the oil phase in a volume ratio of 1: (2.5-3), add the oil phase to the aqueous phase, stir magnetically for 15-20 minutes, then add 4-6wt% calcium chloride, stir for 25-30 minutes, stand and cross-link until the precipitate is obviously separated, centrifuge and filter, and wash with physiological saline for 2-3 times to obtain sodium alginate-protein copolymer microcapsules; S3.3: Evenly mix 10-20 parts by weight of sodium alginate-protein copolymer sustained-release microcapsules, 2-3 parts by weight of β-cyclodextrin and 90-100 parts by weight of purified water, then add 15-25 parts by weight of fructose syrup, 0.3-0.4 parts by weight of mono- and di-glycerol fatty acid esters, 0.1-0.2 parts by weight of locust bean gum and 0.2-0.3 parts by weight of sodium carboxymethyl cellulose, homogenize for 10-12 minutes and then can the mixture to obtain a beverage based on composite fermented inulin.

[0009] Furthermore, in step S1.1, the container with uniform ventilation holes has a hole size of 1-1.5 cm and a thickness of 2.5-3.5 cm.

[0010] Furthermore, in step S2.1, Bifidobacterium breve and Bifidobacterium longum are cultured in MRS liquid culture medium at 37-37.5° C., and Streptococcus thermophilus is cultured in MC liquid culture medium at 42-45° C.

[0011] Furthermore, the quantitative ratio of Bifidobacterium breve, Bifidobacterium longum and Streptococcus thermophilus in the composite bacterial suspension of step S2.1 is 1:(2-3):(1.5-2).

[0012] Furthermore, the inoculation concentration of the composite bacterial solution in step S2.2 is 1.5-2%.

[0013] Furthermore, in step S3.3, the homogenization temperature is 45-50° C. and the homogenization pressure is 80-100 bar.

[0014] A beverage based on composite fermented inulin is prepared by the above-mentioned preparation process of a beverage based on composite fermented inulin.

[0015] The beneficial effects are as follows: 1. The present invention extrudes quinoa protein and sodium alginate, and during the extrusion process, quinoa protein and sodium alginate undergo a covalent bonding reaction to generate a sodium alginate-quinoa protein copolymer, and then the sodium alginate-quinoa protein copolymer and inulin fermentation liquid are mixed to obtain an aqueous phase, and soybean oil containing polyglycerol ricinoleate is added as an oil phase, and calcium chloride is added for cross-linking. At this time, the inulin fermentation liquid enters the oil phase, and the sodium alginate used as the embedding wall material can improve the strength, toughness and stability of the embedding wall material by copolymerizing with quinoa protein having good hydrophilicity and stability, greatly reducing the rupture and deformation of the sodium alginate-protein copolymer microcapsules during storage and transportation, ensuring that the nutrients of the inulin fermentation liquid can be stably sustained-released, and after entering the stomach, the tolerance of sodium alginate to the acidic environment can prevent the probiotics in the inulin fermentation liquid from being destroyed by gastric acid in large quantities, ensuring that the components can pass through the stomach and be gradually released in the intestine, which helps to improve the bioavailability of nutrients in the inulin fermentation liquid and enhance the functionality of the product.

[0016] 2. The present invention combines radio frequency drying and a hot air system, first performs radio frequency drying, then increases power and temperature, and simultaneously starts hot air drying and radio frequency drying for linked drying. During the radio frequency heating process, moisture inside the Jerusalem artichoke can be quickly removed by uniform heating, reducing thermal damage, thereby effectively retaining heat-sensitive nutrients in the Jerusalem artichoke, such as polysaccharides, and the subsequent addition of a hot air system helps to quickly evaporate surface moisture, significantly improving drying efficiency, reducing energy consumption, and further reducing the destruction of nutrients in the Jerusalem artichoke.

[0017] 3. The present invention ferments the inulin fermentation matrix by using a composite bacterial liquid of three species of Bifidobacterium breve, Bifidobacterium longum and Streptococcus thermophilus. The composite bacterial liquid can not only promote the conversion of beneficial components in inulin, but also synergize with each other to improve the fermentation effect. Bifidobacterium breve and Bifidobacterium longum contribute to the fermentation of soluble sugars in inulin, while Streptococcus thermophilus can produce acidic substances, thereby improving the metabolic efficiency of inulin during the fermentation process. The added soy whey protein is acidified under the acidic conditions formed by fermentation, thereby enhancing the hydrophobic interaction between proteins and the interaction force between hydrogen bonds, providing more cross-linking points for quinoa protein in the subsequent encapsulation process, so that the quinoa protein can first form a wall material inward, and then the sodium alginate is cross-linked to form the outermost wall material, thereby enhancing the gel network structure of the encapsulated wall material, and preventing the quinoa protein from being destroyed by the acidic environment in the outer layer, thereby further enhancing the stability of the sodium alginate-protein copolymer microcapsules. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1This is a flow chart of the preparation process of a beverage based on composite fermented inulin adopted in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0020] Example 1: A preparation process of a beverage based on composite fermented inulin, such as Figure 1 As shown, the following steps are included:

[0021] S1: Preparation of high nutritional inulin solution S1.1: Wash the freshly picked Jerusalem artichoke tubers with deionized water, and then cut them into thin slices with a thickness of 4 mm to obtain Jerusalem artichoke slices. Place the Jerusalem artichoke slices vertically in a container with uniform ventilation holes, the hole size of the container is 1 cm, and the thickness is 2.5 cm. Then place them in the middle of the lower plate of a radio frequency dryer equipped with a hot air system, adjust the spacing between the upper and lower plates to 7 cm, adjust the radio frequency power to 600 W, and the temperature to 45°C. Dry for 50 minutes, then adjust the radio frequency power of the radio frequency dryer to 800 W and the temperature to 55°C. Start the hot air system at the same time, adjust the hot air power of the hot air system to 2 kW, and the hot air temperature to 55°C. Dry the Jerusalem artichoke slices with hot air, take them out every 30 minutes for weighing, until the moisture content of the Jerusalem artichoke slices drops below 10%, and obtain dried Jerusalem artichoke slices. S1.2: The dried Jerusalem artichoke slices were crushed in a grinder, and then passed through a 60-mesh sieve to obtain Jerusalem artichoke dry powder. The Jerusalem artichoke dry powder was mixed with an ethanol solution having a volume fraction of 80% at a solid-liquid ratio of 1:20 g / mL, and then placed in an ultrasonic disperser for treatment at an ultrasonic power of 300 W for 25 minutes. The precipitate I was collected by filtration, and the precipitate I was mixed and stirred evenly with deionized water at a solid-liquid ratio of 1:25 g / mL, and then added to an ultrasonic homogenizer for treatment at an ultrasonic power of 350 W and an ultrasonic temperature of 35°C for 25 minutes. , then add it to a microwave heating instrument and treat it with a microwave power of 400 W for 4 minutes, then place it in a centrifuge and centrifuge it at a speed of 4000 rpm for 10 minutes, take the supernatant and evaporate and concentrate it to 1 / 4 of the original volume, add 4 times the volume of anhydrous ethanol and stir evenly, then let it stand at 3°C ​​for 10 hours, filter and collect precipitate II, dissolve precipitate II in deionized water at a solid-liquid ratio of 1:20 g / mL, add it to a dialysis bag and dialyze it with deionized water for 45 hours, and change the water every 4 hours to obtain a high-nutrition inulin solution.

[0022] S2: Preparation of composite bacterial solution and fermentation of inulin protein solution S2.1: The frozen Bifidobacterium breve culture medium, Bifidobacterium longum culture medium and Streptococcus thermophilus were placed in a clean bench for streaking, anaerobically cultured at 35°C for 48 hours, and then the largest single colony was selected and cultured in culture medium for 48 hours. Bifidobacterium breve and Bifidobacterium longum were cultured in MRS liquid culture medium at 37°C, and Streptococcus thermophilus was cultured in MC liquid culture medium at 42°C. After one passage, anaerobically cultured for 24 hours, and then placed in Centrifuge at 6000 rpm for 3 minutes in a centrifuge, separate and discard the supernatant, resuspend and rinse the remaining suspension twice with sterile water to obtain a suspension of Bifidobacterium breve, a suspension of Bifidobacterium longum and a suspension of Streptococcus thermophilus, mix and shake the suspension of Bifidobacterium breve, the suspension of Bifidobacterium longum and the suspension of Streptococcus thermophilus evenly to obtain a composite bacterial suspension, wherein the number ratio of Bifidobacterium breve, Bifidobacterium longum and Streptococcus thermophilus in the composite bacterial suspension is 1:2:1.5; S2.2: The high-nutrition inulin solution obtained in step S1.2 is evaporated and concentrated to 25% of the original volume, and then 8wt% of soy whey protein and 1wt% of soft white sugar are added, stirred evenly and sterilized at 121°C for 10 minutes, and sterile water is added to keep the volume unchanged to obtain an inulin fermentation matrix. Under sterile conditions, the composite bacterial liquid is inoculated into the inulin fermentation matrix at an inoculation concentration of 1.5%, and fermented at a constant temperature of 37°C for 20 hours to obtain an inulin fermentation liquid.

[0023] S3: Microencapsulation of inulin fermentation broth S3.1: placing quinoa protein and sodium alginate in a mixer at a mass ratio of 1:6, mixing them thoroughly, and then adding them into a twin-screw extruder, controlling the moisture content of the mixture to 35%, adjusting the screw speed to 140 rpm, and extruding at a temperature of 120° C., and then drying at 40° C. to obtain a sodium alginate-quinoa protein copolymer; S3.2: Inulin fermentation broth and physiological saline were mixed in a volume ratio of 1:3, and then 6wt% of sodium alginate-quinoa protein copolymer was added, and stirred at a stirring speed of 200rpm for 15 minutes to obtain an aqueous phase, 1.5wt% of polyglycerol ricinoleate was added to soybean oil, and stirred until the polyglycerol ricinoleate was completely dissolved to obtain an oil phase, and the aqueous phase and oil phase were measured in a volume ratio of 1:2.5, and the oil phase was added to the aqueous phase for 15 minutes of magnetic stirring, and then 4wt% of calcium chloride was added and stirred for 25 minutes, and the mixture was allowed to stand for cross-linking until the precipitate was obviously separated, and then centrifuged and filtered and washed twice with physiological saline to obtain sodium alginate-protein copolymer microcapsules; S3.3: Evenly mix 10 parts by weight of sodium alginate-protein copolymer sustained-release microcapsules, 2 parts by weight of β-cyclodextrin and 90 parts by weight of purified water, then add 15 parts by weight of fructose syrup, 0.3 parts by weight of mono- and di-glycerol fatty acid esters, 0.1 parts by weight of locust bean gum and 0.2 parts by weight of sodium carboxymethyl cellulose, homogenize at a homogenization temperature of 45°C and a homogenization pressure of 80 bar for 10 minutes, and then can the mixture to obtain a beverage based on composite fermented inulin.

[0024] Example 2: A preparation process of a beverage based on composite fermented inulin, such as Figure 1 As shown, the following steps are included: S1: Preparation of high nutritional inulin solution S1.1: Wash the freshly picked Jerusalem artichoke tubers with deionized water, and then cut them into thin slices with a thickness of 4 mm to obtain Jerusalem artichoke slices. Place the Jerusalem artichoke slices vertically in a container with uniform ventilation holes, the hole size of the container is 1 cm, and the thickness is 2.5 cm. Then place them in the middle of the lower plate of a radio frequency dryer equipped with a hot air system, adjust the spacing between the upper and lower plates to 7 cm, adjust the radio frequency power to 600 W, and the temperature to 45°C. Dry for 50 minutes, then adjust the radio frequency power of the radio frequency dryer to 800 W and the temperature to 55°C. Start the hot air system at the same time, adjust the hot air power of the hot air system to 2 kW, and the hot air temperature to 55°C. Dry the Jerusalem artichoke slices with hot air, take them out every 30 minutes for weighing, until the moisture content of the Jerusalem artichoke slices drops below 10%, and obtain dried Jerusalem artichoke slices. S1.2: The dried Jerusalem artichoke slices were crushed in a grinder, and then passed through a 60-mesh sieve to obtain Jerusalem artichoke dry powder. The Jerusalem artichoke dry powder was mixed with an ethanol solution having a volume fraction of 80% at a solid-liquid ratio of 1:25 g / mL, and then placed in an ultrasonic disperser for treatment at an ultrasonic power of 300 W for 25 minutes. The precipitate I was collected by filtration, and the precipitate I was mixed and stirred evenly with deionized water at a solid-liquid ratio of 1:30 g / mL, and then added to an ultrasonic homogenizer for treatment at an ultrasonic power of 350 W and an ultrasonic temperature of 35°C for 25 minutes. , then add it to a microwave heating instrument and treat it with a microwave power of 400 W for 4 minutes, then place it in a centrifuge and centrifuge it at a speed of 4000 rpm for 10 minutes, take the supernatant and evaporate and concentrate it to 1 / 4 of the original volume, add 5 times the volume of anhydrous ethanol and stir evenly, then let it stand at 3°C ​​for 10 hours, filter and collect precipitate II, dissolve precipitate II in deionized water at a solid-liquid ratio of 1:25 g / mL, add it to a dialysis bag and dialyze it with deionized water for 45 hours, change the water every 4 hours, and obtain a high-nutrition inulin solution.

[0025] S2: Preparation of composite bacterial solution and fermentation of inulin protein solution S2.1: The frozen Bifidobacterium breve culture stock solution, Bifidobacterium longum culture stock solution and Streptococcus thermophilus were placed in a clean bench for streaking, and anaerobically cultured at 35°C for 48 hours. The largest single colony was then selected and cultured in culture medium for 48 hours. Bifidobacterium breve and Bifidobacterium longum were cultured in MRS liquid culture medium at 37°C, and Streptococcus thermophilus was cultured in MC liquid culture medium at 42°C. After one subculture, they were anaerobically cultured for 24 hours, and then cultured separately. Place in a centrifuge and centrifuge at a speed of 6000 rpm for 3 minutes, separate and discard the supernatant, resuspend and rinse the remaining suspension twice with sterile water to obtain a suspension of Bifidobacterium breve, a suspension of Bifidobacterium longum and a suspension of Streptococcus thermophilus, mix and shake the suspension of Bifidobacterium breve, the suspension of Bifidobacterium longum and the suspension of Streptococcus thermophilus evenly to obtain a composite bacterial suspension, wherein the number ratio of Bifidobacterium breve, Bifidobacterium longum and Streptococcus thermophilus in the composite bacterial suspension is 1:3:2; S2.2: The high-nutrition inulin solution obtained in step S1.2 is evaporated and concentrated to 25% of the original volume, and then 10wt% of soy whey protein and 1.5wt% of soft white sugar are added, stirred evenly and sterilized at 121°C for 10 minutes, and sterile water is added to keep the volume unchanged to obtain an inulin fermentation matrix. Under sterile conditions, the composite bacterial liquid is inoculated into the inulin fermentation matrix at an inoculation concentration of 2%, and fermented at a constant temperature of 37°C for 20 hours to obtain an inulin fermentation liquid.

[0026] S3: Microencapsulation of inulin fermentation broth S3.1: placing quinoa protein and sodium alginate in a mixer at a mass ratio of 1:8, mixing them thoroughly, and then adding them into a twin-screw extruder, controlling the moisture content of the mixture to be 35%, adjusting the screw speed to 140 rpm, and extruding at a temperature of 120°C for extrusion, and then drying at 40°C to obtain a sodium alginate-quinoa protein copolymer; S3.2: Inulin fermentation broth and physiological saline were mixed in a volume ratio of 1:5, and then 8wt% of sodium alginate-quinoa protein copolymer was added, and stirred at a stirring speed of 200rpm for 15 minutes to obtain an aqueous phase, 2wt% of polyglycerol ricinoleate was added to soybean oil, and stirred until the polyglycerol ricinoleate was completely dissolved to obtain an oil phase, and the aqueous phase and oil phase were measured in a volume ratio of 1:3, and the oil phase was added to the aqueous phase for 15 minutes of magnetic stirring, and then 6wt% of calcium chloride was added and stirred for 25 minutes, and the mixture was allowed to stand for cross-linking until the precipitate was obviously separated, and then centrifuged and filtered and washed twice with physiological saline to obtain sodium alginate-protein copolymer microcapsules; S3.3: Mix 20 parts by weight of sodium alginate-protein copolymer sustained-release microcapsules, 3 parts by weight of β-cyclodextrin and 100 parts by weight of purified water, then add 25 parts by weight of fructose syrup, 0.4 parts by weight of mono- and di-glycerol fatty acid esters, 0.2 parts by weight of locust bean gum and 0.3 parts by weight of sodium carboxymethyl cellulose, homogenize at a homogenization temperature of 45°C and a homogenization pressure of 80 bar for 10 minutes, and then cannify to obtain a beverage based on composite fermented inulin.

[0027] Example 3: A preparation process of a beverage based on composite fermented inulin, such as Figure 1 As shown, the following steps are included:

[0028] S1: Preparation of high nutritional inulin solution S1.1: Wash the freshly picked Jerusalem artichoke tubers with deionized water, and then cut them into thin slices with a thickness of 6 mm to obtain Jerusalem artichoke slices. Place the Jerusalem artichoke slices vertically in a container with uniform ventilation holes, the hole size of the container is 1.5 cm, and the thickness is 3.5 cm. Then place them in the middle of the lower plate of a radio frequency dryer equipped with a hot air system, adjust the spacing between the upper and lower plates to 8 cm, adjust the radio frequency power to 650 W, and the temperature to 50 ° C. Dry for 60 minutes, then adjust the radio frequency power of the radio frequency dryer to 850 W and the temperature to 60 ° C. At the same time, start the hot air system, adjust the hot air power of the hot air system to 3 kW, and the hot air temperature to 60 ° C. Hot air dry the Jerusalem artichoke slices, take them out every 40 minutes for weighing, until the moisture content of the Jerusalem artichoke slices drops below 10%, to obtain dried Jerusalem artichoke slices; S1.2: The dried Jerusalem artichoke slices were crushed in a grinder, and then passed through an 80-mesh sieve to obtain Jerusalem artichoke dry powder. The Jerusalem artichoke dry powder was mixed with an ethanol solution having a volume fraction of 85% at a solid-liquid ratio of 1:20 g / mL, and then placed in an ultrasonic disperser for treatment at an ultrasonic power of 350 W for 30 minutes. The precipitate I was collected by filtration, and the precipitate I was mixed and stirred evenly with deionized water at a solid-liquid ratio of 1:25 g / mL, and then added to an ultrasonic homogenizer for treatment at an ultrasonic power of 400 W and an ultrasonic temperature of 40°C for 30 minutes. , then add it to a microwave heating instrument and treat it with a microwave power of 450 W for 5 minutes, then place it in a centrifuge and centrifuge it at a speed of 4500 rpm for 15 minutes, take the supernatant and evaporate and concentrate it to 1 / 3 of the original volume, add 4 times the volume of anhydrous ethanol and stir evenly, then let it stand at 4°C for 12 hours, filter and collect precipitate II, dissolve precipitate II in deionized water at a solid-liquid ratio of 1:20 g / mL, add it to a dialysis bag and dialyze it with deionized water for 48 hours, and change the water every 5 hours to obtain a high-nutrition inulin solution.

[0029] S2: Preparation of composite bacterial solution and fermentation of inulin protein solution S2.1: The frozen Bifidobacterium breve culture stock solution, Bifidobacterium longum culture stock solution and Streptococcus thermophilus were placed in a clean bench for streaking, and anaerobically cultured at 37°C for 50 hours. The largest single colony was then selected and cultured in culture medium for 50 hours. Bifidobacterium breve and Bifidobacterium longum were cultured in MRS liquid culture medium at 37.5°C, and Streptococcus thermophilus was cultured in MC liquid culture medium at 45°C. After one subculture, they were anaerobically cultured for 28 hours, and then cultured separately. The mixture was centrifuged at 8000 rpm for 4 minutes, and the supernatant was separated and discarded. The remaining suspension was resuspended and rinsed 3 times with sterile water to obtain a suspension of Bifidobacterium breve, a suspension of Bifidobacterium longum and a suspension of Streptococcus thermophilus. The suspension of Bifidobacterium breve, the suspension of Bifidobacterium longum and the suspension of Streptococcus thermophilus were mixed and shaken evenly to obtain a composite bacterial suspension. The ratio of Bifidobacterium breve, Bifidobacterium longum and Streptococcus thermophilus in the composite bacterial suspension was 1:2:1.5. S2.2: The high-nutrition inulin solution obtained in step S1.2 is evaporated and concentrated to 30% of the original volume, and then 8wt% of soy whey protein and 1wt% of soft white sugar are added, stirred evenly and sterilized at 125°C for 15 minutes, and sterile water is added to keep the volume unchanged to obtain an inulin fermentation matrix. Under sterile conditions, the composite bacterial liquid is inoculated into the inulin fermentation matrix at an inoculation concentration of 1.5%, and fermented at a constant temperature of 37.5°C for 25 hours to obtain an inulin fermentation liquid.

[0030] S3: Microencapsulation of inulin fermentation broth S3.1: placing quinoa protein and sodium alginate in a mixer at a mass ratio of 1:6, mixing them thoroughly, and then adding them into a twin-screw extruder, controlling the moisture content of the mixture to 40%, adjusting the screw speed to 160 rpm, and extruding at a temperature of 125°C, and then drying at 45°C to obtain a sodium alginate-quinoa protein copolymer; S3.2: Inulin fermentation broth and physiological saline were mixed in a volume ratio of 1:3, and then 6wt% of sodium alginate-quinoa protein copolymer was added, and stirred at a stirring speed of 250rpm for 20 minutes to obtain an aqueous phase, 1.5wt% of polyglycerol ricinoleate was added to soybean oil, and stirred until the polyglycerol ricinoleate was completely dissolved to obtain an oil phase, and the aqueous phase and oil phase were measured in a volume ratio of 1:2.5, and the oil phase was added to the aqueous phase for 20 minutes of magnetic stirring, and then 4wt% of calcium chloride was added and stirred for 30 minutes, and the mixture was allowed to stand for cross-linking until the precipitate was obviously separated, and then centrifuged and filtered and washed 3 times with physiological saline to obtain sodium alginate-protein copolymer microcapsules; S3.3: Evenly mix 10 parts by weight of sodium alginate-protein copolymer sustained-release microcapsules, 2 parts by weight of β-cyclodextrin and 90 parts by weight of purified water, then add 15 parts by weight of fructose syrup, 0.3 parts by weight of mono- and di-glycerol fatty acid esters, 0.1 parts by weight of locust bean gum and 0.2 parts by weight of sodium carboxymethyl cellulose, homogenize at a homogenization temperature of 50°C and a homogenization pressure of 100 bar for 12 minutes, and then cannify to obtain a beverage based on composite fermented inulin.

[0031] Comparative Example 1: Compared with Example 1, the difference of Comparative Example 1 is that step S3.1 is removed in Comparative Example 1, and the sodium alginate-quinoa protein copolymer in step S3.2 is replaced with an equal mass of sodium alginate, and the remaining steps are the same as those in Example 1 to prepare sodium alginate-protein copolymer microcapsules, and the prepared sodium alginate-protein copolymer microcapsules are recorded as Comparative Example 1.

[0032] Comparative Example 2: Compared with Example 1, the difference of Comparative Example 2 is that Comparative Example 2 eliminates the steps of radio frequency drying and hot air drying the Jerusalem artichoke slices in step S1, and directly places the Jerusalem artichoke slices in an oven at 60°C and drys them for 24 hours. The remaining steps are the same as those in Example 1, and the obtained Jerusalem artichoke powder is recorded as Comparative Example 2.

[0033] Comparative Example 3: Compared with Example 1, the difference of Comparative Example 3 is that soybean whey protein is not added in step S2.2 of Comparative Example 3, and the remaining steps are the same as those of Example 1. The prepared sodium alginate-protein copolymer microcapsules are recorded as Comparative Example 3.

[0034] Live bacteria test: 1 g of the sodium alginate-protein copolymer microcapsules prepared in Examples 1-3, Comparative Example 1 and Comparative Example 3 were taken as samples, respectively, and dissolved in 9 mL of sterile buffer (a mixture of 0.2 mol / L sodium bicarbonate and 0.06 mol / L sodium citrate), and gently shaken for 10 minutes until completely dissolved, and the live bacteria were counted on MRS agar using the plate count method, recorded as N1; Storage stability test: The sodium alginate-protein copolymer microcapsules prepared in Examples 1-3, Comparative Example 1 and Comparative Example 3 were taken as samples, 10 g of each was stored at 4°C, 25°C and -20°C for 60 days, and then the live bacteria were counted using the above-mentioned live bacteria test method, recorded as N2, and the bacterial survival rate was calculated as (N1-N2 / 10) / N1×100%, and the data was recorded and tabulated as shown in Table 1; Stability test in gastric fluid environment: 0.3 g / L pepsin solution (2 g / L saline) was used to prepare simulated artificial gastric fluid, and the pH was adjusted to 2.0 with concentrated hydrochloric acid to simulate the acid in the stomach. The sodium alginate-protein copolymer microcapsules prepared in Examples 1-3, Comparative Example 1 and Comparative Example 3 were used as samples, 1 g was taken and mixed in 9 mL of artificial gastric fluid, incubated at 37 ° C, 160 rpm for 2 hours, and then the live bacteria were counted using the above-mentioned live bacteria test method, recorded as N3, repeated three times, and the bacterial survival rate was calculated = (N1-N3) / N1×100%, and the data was recorded and tabulated as shown in Table 2.

[0035] Table 1: Storage performance at different temperatures Survival rate / % 4℃ 25℃ -20℃ Example 1 46.7 31.2 52.5 Example 2 48.3 34.9 53.4 Example 3 47.6 33.8 55.8 Comparative Example 1 40.5 22.7 44.6 Comparative Example 3 43.5 25.8 48.2 Table 2: Storage performance at different temperatures Survival rate / % first Second time The third time Example 1 94.2 93.7 94.5 Example 2 95.6 95.1 95.3 Example 3 93.8 93.5 94.1 Comparative Example 1 92.8 93.1 92.6 Comparative Example 3 81.4 82.5 81.9 According to the data of the embodiment, comparative example 1 and comparative example 3 in Table 1, it can be seen that the survival rate of live bacteria in the sodium alginate-protein copolymer microcapsules prepared in the embodiment is greater than that of comparative example 1 and comparative example 3 after storage for 60 days at 4°C, room temperature and -20°C. This proves that the preparation of sodium alginate-quinoa protein copolymer for encapsulation of inulin fermentation broth can improve the storage stability of the microcapsules. It can also be proved that the addition of soy whey protein to the high-nutrition inulin solution can enhance the gel network structure of the encapsulated wall material, thereby further enhancing the stability of the sodium alginate-protein copolymer microcapsules.

[0036] According to the data of the embodiment, comparative example 1 and comparative example 3 in Table 2, it can be seen that in the gastric acid environment, the survival rate of live bacteria in the sodium alginate-protein copolymer microcapsules prepared in the embodiment is greater than that in comparative example 3 and is not much different from that in comparative example 1, which can prove that adding soy whey protein to the high-nutrition inulin solution can enable quinoa protein to form a wall material inward first, and can prevent quinoa protein from being destroyed by the acidic environment in the outer layer. The reason why the data of embodiment 1 and comparative example 1 are not much different is that the main component that is tolerant to gastric acid is sodium alginate, and the sodium alginate component in the wall material of the sodium alginate-protein copolymer microcapsules prepared in embodiment 1 and comparative example 1 is not much different.

[0037] Inulin content test: Three equal portions of Jerusalem artichoke powder prepared in Example 1 and Comparative Example 2 were taken as samples, and the inulin content in the samples was determined. The inulin content in the product was (total sugar content-reducing sugar content) / total sugar content × 100%. The total sugar content was determined by sulfuric acid phenol colorimetry, and the reducing sugar content was determined by DNS colorimetry. The results are shown in Table 3.

[0038] Table 3: Content of inulin in Jerusalem artichoke powder Inulin content / % The first Second copy The third Example 1 93.2 92.9 93.4 Comparative Example 2 82.9 83.1 82.6 It can be seen from Table 3 that the inulin content in the Jerusalem artichoke dry powder prepared in Example 1 is higher than that in Comparative Example 2, which proves that the combination of radio frequency drying and hot air system can effectively retain the heat-sensitive nutrients in Jerusalem artichoke.

[0039] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A preparation process of a beverage based on composite fermented inulin, characterized in that: The following steps are involved: S1: Preparation of high nutritional inulin solution The Jerusalem artichoke tubers are washed and sliced, and then put into a container, and then placed in a radio frequency dryer equipped with a hot air system for radio frequency drying, and then the radio frequency power and temperature are increased, and the hot air system is turned on for drying to obtain dried Jerusalem artichoke slices, and the dried Jerusalem artichoke slices are crushed and then degreased, and then ultrasonic extraction and microwave extraction are sequentially performed, and the supernatant is centrifuged for alcohol precipitation, and a high-nutrition inulin solution is obtained after dialysis; S2: Preparation of composite bacterial solution and fermentation of inulin protein solution Streaking culture is performed on frozen Bifidobacterium breve bacterial stock solution, Bifidobacterium longum bacterial stock solution and Streptococcus thermophilus, taking the largest single colony and placing it in a culture medium for culture, centrifuging and resuspending and rinsing, mixing the obtained three bacterial suspensions to obtain a composite bacterial suspension, concentrating the high-nutrition inulin solution, adding soy whey protein and soft white sugar, sterilizing to obtain an inulin fermentation matrix, and fermenting the inulin fermentation matrix with the composite bacterial suspension to obtain an inulin fermentation liquid; S3: Microencapsulation of inulin fermentation broth Quinoa protein and sodium alginate are blended and extruded to obtain sodium alginate-quinoa protein copolymer, inulin fermentation liquid and physiological saline are mixed and then added with sodium alginate-quinoa protein copolymer to obtain an aqueous phase, polyglycerol ricinoleate is dissolved in soybean oil to obtain an oil phase, the oil phase is added to the aqueous phase and stirred, calcium chloride is added and stirred continuously, and the mixture is allowed to stand and then centrifuged and washed to obtain sodium alginate-protein copolymer microcapsules, sodium alginate-protein copolymer sustained-release microcapsules, β-cyclodextrin and purified water are evenly mixed, and fructose syrup, mono- and di-glycerol fatty acid esters, locust bean gum and sodium carboxymethyl cellulose are added and homogenized to obtain a beverage based on composite fermented inulin.

2. The preparation process of a beverage based on composite fermented inulin according to claim 1, characterized in that: Step S1: Preparation of high-nutrient inulin solution, comprising the following steps: S1.1: Wash the freshly picked Jerusalem artichoke tubers with deionized water, and then cut them into thin slices with a thickness of 4-6 mm to obtain Jerusalem artichoke slices. Place the Jerusalem artichoke slices vertically in a container with uniform ventilation holes, and then place them in the middle of the lower plate of a radio frequency dryer equipped with a hot air system. Adjust the spacing between the upper and lower plates to 7-8 cm, the radio frequency power to 600-650 W, the temperature to 45-50 ° C, and dry for 50-60 minutes. Then adjust the radio frequency power of the radio frequency dryer to 800-850 W and the temperature to 55-60 ° C. At the same time, start the hot air system, adjust the hot air power of the hot air system to 2-3 kW, and the hot air temperature to 55-60 ° C. Hot air drying the Jerusalem artichoke slices, take them out every 30-40 minutes for weighing, until the moisture content of the Jerusalem artichoke slices drops below 10%, to obtain dried Jerusalem artichoke slices; S1.2: The dried Jerusalem artichoke slices are placed in a grinder and crushed, and then passed through a 60-80 mesh sieve to obtain Jerusalem artichoke dry powder. The Jerusalem artichoke dry powder is mixed with an ethanol solution with a volume fraction of 80-85% at a solid-liquid ratio of 1: (20-25) g / mL, and then placed in an ultrasonic disperser for treatment at an ultrasonic power of 300-350 W for 25-30 minutes, and the precipitate I is collected by filtration. The precipitate I is mixed and stirred evenly with deionized water at a solid-liquid ratio of 1: (25-30) g / mL, and then added to an ultrasonic homogenizer for treatment at an ultrasonic power of 350-400 W and an ultrasonic temperature of 35-40°C for 25-30 minutes. The mixture was then added to a microwave heating apparatus and treated with a microwave power of 400-450 W for 4-5 minutes, and then placed in a centrifuge and centrifuged at a speed of 4000-4500 rpm for 10-15 minutes. The supernatant was evaporated and concentrated to 1 / 4-1 / 3 of the original volume, 4-5 times the volume of anhydrous ethanol was added and stirred evenly, and then allowed to stand at 3-4°C for 10-12 hours, and precipitate II was collected by filtration. The precipitate II was dissolved in deionized water at a solid-liquid ratio of 1: (20-25) g / mL, and added to a dialysis bag for dialyzing with deionized water for 45-48 hours, and the water was changed every 4-5 hours to obtain a high-nutrition inulin solution.

3. The preparation process of a beverage based on composite fermented inulin according to claim 2, characterized in that: Step S2: preparation of the composite bacterial solution and fermentation of the inulin protein solution, comprising the following steps: S2.1: The frozen Bifidobacterium breve bacterial stock solution, Bifidobacterium longum bacterial stock solution and Streptococcus thermophilus were placed in a clean bench for streaking, anaerobically cultured at 35-37°C for 48-50 hours, and then the largest single colonies were selected and placed in culture medium for culture for 48-50 hours, and then cultured anaerobically for 24-28 hours after one passage, and then placed in a centrifuge for centrifugation at a speed of 6000-8000 rpm for 3-4 minutes, and the supernatant was separated and discarded. The remaining suspension was resuspended and rinsed with sterile water for 2-3 times to obtain Bifidobacterium breve bacterial suspension, Bifidobacterium longum bacterial suspension and Streptococcus thermophilus suspension, and the Bifidobacterium breve bacterial suspension, Bifidobacterium longum bacterial suspension and Streptococcus thermophilus bacterial suspension were mixed and shaken evenly to obtain a composite bacterial suspension; S2.2: The high-nutrition inulin solution obtained in step S1.2 is evaporated and concentrated to 25-30% of the original volume, and then 8-10wt% of soy whey protein and 1-1.5wt% of soft white sugar are added, stirred evenly and sterilized at 121-125°C for 10-15 minutes, and sterile water is added to keep the volume unchanged to obtain an inulin fermentation matrix, and the composite bacterial liquid is inoculated into the inulin fermentation matrix under sterile conditions, and fermented at a constant temperature of 37-37.5°C for 20-25 hours to obtain an inulin fermentation liquid.

4. The preparation process of a beverage based on composite fermented inulin according to claim 3, characterized in that: Step S3, microencapsulation of inulin fermentation broth, comprises the following steps: S3.1: placing quinoa protein and sodium alginate in a mixer at a mass ratio of 1:(6-8) and fully mixing them, and then adding them into a twin-screw extruder, controlling the moisture content of the mixture to be 35-40%, adjusting the screw speed to 140-160rpm, and extruding at a temperature of 120-125°C, and then drying at 40-45°C to obtain a sodium alginate-quinoa protein copolymer; S3.2: Mix inulin fermentation broth and physiological saline in a volume ratio of 1: (3-5), then add 6-8wt% sodium alginate-quinoa protein copolymer, stir at a stirring speed of 200-250rpm for 15-20 minutes to obtain an aqueous phase, add 1.5-2wt% polyglycerol ricinoleate to soybean oil, stir until the polyglycerol ricinoleate is completely dissolved, and obtain an oil phase, measure the aqueous phase and the oil phase in a volume ratio of 1: (2.5-3), add the oil phase to the aqueous phase, stir magnetically for 15-20 minutes, then add 4-6wt% calcium chloride, stir for 25-30 minutes, stand and cross-link until the precipitate is obviously separated, centrifuge and filter, and wash with physiological saline for 2-3 times to obtain sodium alginate-protein copolymer microcapsules; S3.3: Evenly mix 10-20 parts by weight of sodium alginate-protein copolymer sustained-release microcapsules, 2-3 parts by weight of β-cyclodextrin and 90-100 parts by weight of purified water, then add 15-25 parts by weight of fructose syrup, 0.3-0.4 parts by weight of mono- and di-glycerol fatty acid esters, 0.1-0.2 parts by weight of locust bean gum and 0.2-0.3 parts by weight of sodium carboxymethyl cellulose, homogenize for 10-12 minutes and then can the mixture to obtain a beverage based on composite fermented inulin.

5. The preparation process of a beverage based on composite fermented inulin according to claim 2, characterized in that: Step S1.1 The container with uniform ventilation holes has a hole size of 1-1.5 cm and a thickness of 2.5-3.5 cm.

6. The preparation process of a beverage based on composite fermented inulin according to claim 3, characterized in that: In step S2.1, Bifidobacterium breve and Bifidobacterium longum are cultured in MRS liquid medium at 37-37.5°C, and Streptococcus thermophilus is cultured in MC liquid medium at 42-45°C.

7. The preparation process of a beverage based on composite fermented inulin according to claim 3, characterized in that: The quantitative ratio of Bifidobacterium breve, Bifidobacterium longum and Streptococcus thermophilus in the composite bacterial suspension of step S2.1 is 1:(2-3):(1.5-2).

8. The preparation process of a beverage based on composite fermented inulin according to claim 3, characterized in that: The inoculation concentration of the composite bacterial solution in step S2.2 is 1.5-2%.

9. The process for preparing a beverage based on composite fermented inulin according to claim 4, characterized in that: The homogenization temperature in step S3.3 is 45-50°C and the homogenization pressure is 80-100 bar.

10. A beverage based on composite fermented inulin, characterized in that: The beverage is prepared by the preparation process of a beverage based on composite fermented inulin according to any one of claims 1 to 9.

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