Method for improving thermal stability of vegetable protein beverage

Abstract

The invention discloses a method for improving thermal stability of a vegetable protein beverage. The method comprises the following process steps in sequence: preparing a stock solution: pouring the vegetable protein beverage into a container; degassing treatment: putting the container containing the stock solution of the vegetable protein beverage into a vacuum tank, enabling a vacuum pump to continuously work, and heating and stirring the stock solution in the container at the same time; homogenizing and sterilizing: sterilizing after homogenizing the stock solution; and filling: filling the stock solution treated in the step S3 to obtain the vegetable protein beverage with improved stability. According to the invention, a traditional additive is abandoned, and a vacuumizing degassing method is adopted, so that the flocculation phenomenon is improved essentially, the product is stable, additional additives are not needed, only physical vacuum is needed, and the operation is very convenient. The product is heated and stirred in vacuum, so that gas in liquid is separated to the greatest extent, and high-pressure homogenization can be matched when necessary, so that the product shows very stable characters when the product is matched with colored liquid such as coffee and the like at a terminal.

Description

Technical Field

[0001] The invention relates to the technical field of plant protein flocculation, and in particular to a method for improving the thermal stability of a plant protein beverage. Background Art

[0002] Plant protein will flocculate and stratify at high temperatures, resulting in unstable products, unsightly appearance, and unpleasant taste. If you want to make the product relatively stable and have a good taste, the usual practice is to add a large amount of stabilizers and additives, such as mono- and di-glycerides, microcrystalline cellulose, and various colloids. Patent No. CN109007020A: A method for making a stable fermented plant protein beverage, comprising the following steps: (1) preparing a fermentation base material, (2) dry-mixing a stabilizer and a sweetener and dissolving them with purified water at 65-75°C, (3) mixing the fermentation base material and the stabilizer solution obtained in step (2) evenly, (4) adding flavoring essence for flavoring, (5) heating, homogenizing, and (6) sterilizing and packaging. Patent with publication number CN108419979B: A method for improving the stability of plant protein beverages with high protein and high starch content, which successively adopts the following steps: pretreatment, gelatinization, colloid milling, enzyme hydrolysis, enzyme inactivation, blending, homogenization, filling, and sterilization; the pretreatment is: selecting fresh and non-moldy ginkgo nuts, rinsing them, and removing the shells and skins; the gelatinization is: taking 3% to 6% of the pretreated ginkgo nuts, adding them to a 0.05% to 0.2% sodium carbonate aqueous solution at a temperature of 90 to 100°C, adding 0.05% to 0.1% salt, and gelatinizing for 20 minutes; the colloid milling is: breaking the gelatinized ginkgo nuts, then adding warm water, and grinding them through the colloid mill to obtain ginkgo slurry; the enzymatic hydrolysis is: adding medium-temperature α-amylase and saccharifying enzyme to the slurry formed by the colloid mill at the same time, and hydrolyzing them at 65°C for 30 minutes to 80 minutes; the medium-temperature α -The amount of amylase added is 20-60U per gram of ginkgo, and the amount of saccharifying enzyme added is 30-70U per gram of ginkgo; the enzyme inactivation is: the enzyme inactivation treatment is performed on the hydrolyzed ginkgo juice; the preparation is: adding additives to the enzyme-inactivated ginkgo juice; the amount of additives added is: 0.1-0.3 parts of microcrystalline cellulose, 0.02-0.2 parts of low acyl gellan gum, 0.05-0.25 parts of sucrose fatty acid esters and 0.05-0.25 parts of molecularly distilled monostearate glyceride per 100 parts of the juice; the homogenization is: heating the prepared ginkgo juice to 65°C-75°C, the homogenization pressure is 30MPa-100MPa, and homogenization is performed twice; the filling is: filling the homogenized ginkgo juice and sealing; the sterilization is: sterilizing the filled ginkgo juice. Patent with publication number CN104738191B: A method for improving the stability of plant protein beverages, belonging to the technical field of plant protein beverage processing. The method is: during the processing of the plant protein beverage, the following components in parts by weight are added to every 100 parts of the plant protein beverage: 0.1-0.45 parts of polyglycerol fatty acid ester; 0.05-0.45 parts of sodium bicarbonate or 0.02-0.45 parts of sodium tripolyphosphate or a combination thereof; 0.01-0.1 parts of citric acid or 0.02-0.2 parts of sucrose fatty acid ester or a combination thereof.They all use traditional additives or rely on stabilizers (colloids), that is, chemical methods to ensure the stability of the product. Although this can make the product stable in a short period of time, as the temperature rises, a large amount of flocculation will still be produced, and the original taste will change. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects in the prior art and provide a method for improving the thermal stability of plant protein beverages. The method abandons traditional additives and adopts a vacuum degassing method to essentially improve the flocculation phenomenon, making the product stable without adding other additives and only requiring physical vacuum, which is very convenient to operate.

[0004] To achieve the above object, the technical solution of the present invention is to design a method for improving the thermal stability of a plant protein beverage, comprising the following process steps in sequence: S1: stock solution preparation: pour the plant protein beverage into a container; S2: Degassing treatment: Place the container containing the original liquid of the plant protein beverage into a vacuum tank, and keep the vacuum pump working while heating and stirring the original liquid in the container; S3: Homogenization and sterilization: homogenization and sterilization of the stock solution; S4: Filling: Fill the original liquid treated in step S3 to form a plant protein beverage with improved stability. By vacuum heating and stirring the product, the gas in the liquid is separated to the greatest extent. If necessary, it can be combined with high-pressure homogenization, so that the product can show very stable properties when it is combined with colored liquids such as coffee at the terminal. Rely on physical aspects to enhance the stability of the product. Rely on liquid degassing to make the product stable. Filling adopts Tetra Pak form. Tetra Pak refers to a composite co-extruded of paper, plastic and aluminum after printing. It is used for aseptic filling of liquids such as milk beverages. It is named because the packaging form after molding is square and brick-shaped. Tetra Pak is a series of packaging products for liquid food developed by Swedish Tetra Pak.

[0005] A further technical solution is that in step S2, the vacuum tank is maintained at a vacuum degree of 0.01 atmosphere, the stock solution in the container is heated to 70-75°C and kept at 70-75°C for 30 minutes; the stirring rate is 100 rpm. The stock solution is placed in the vacuum tank, the vacuum degree is 0.01 atmosphere, and the vacuum pump is continuously operated to ensure that the exhausted gas can be immediately extracted.

[0006] A further technical solution is that in step S3, the stock solution is homogenized once, and the homogenization pressure is 250-260 bar. There is no requirement for the homogenization rate.

[0007] A further technical solution is that in step S3, UHT sterilization is used for sterilization, and the sterilization parameters are: sterilization temperature 137°C, sterilization time 10s. UHT (Ultra-high temperature instantaneous sterilization) is a sterilization process for fresh milk processing (existing technology), ultra-high temperature instantaneous sterilization, 135-150°C, 2-8 seconds, can be stored without refrigeration below 10°C, and the shelf life can reach 1-6 months.

[0008] A further technical solution is that the homogenization process is carried out using a homogenizer, the homogenizer includes a reducer fixedly mounted on a base, the output shaft of the reducer is fixedly connected to a rotating shaft, a rotor is fixedly mounted on the rotating shaft, a stator fixedly connected to the base is arranged outside the rotor, a liquid inlet pipe is connected to the stator, the middle section of the liquid inlet pipe is a rubber elastic section; a reduction motor is fixedly mounted on a section of the liquid inlet pipe located beside the middle section, and a cam mechanism is connected to the output shaft of the reduction motor.

[0009] The advantages and beneficial effects of the present invention are: when the existing product is heated to above 50°C, no flocculent substances will appear, and without being polluted, the product will not be delaminated within 60 minutes.

[0010] The traditional additives are abandoned and the vacuum degassing method is adopted instead, which essentially improves the flocculation phenomenon, makes the product stable without adding other additives, and only requires physical vacuum, which is very convenient to operate.

[0011] By vacuum heating and stirring the product, the gas in the liquid can be separated to the greatest extent possible. If necessary, high-pressure homogenization can be used. This way, the product can exhibit very stable properties when mixed with colored liquids such as coffee at the terminal.

[0012] The present invention relies on physical enhancement of product stability and relies on liquid degassing to stabilize the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of a homogenizer in Embodiment 4 of a method for improving thermal stability of a plant protein beverage of the present invention; Figure 2 yes Figure 1 The main view; Figure 3 yes Figure 2 AA section view; Figure 4 yes Figure 2 An enlarged schematic diagram of the upper end portion of Figure 5 yes Figure 4 Schematic diagram of the middle reduction motor and cam mechanism after rotating 90° counterclockwise; Figure 6 yes Figure 5 Schematic diagram of the cam mechanism; Figure 7 yes Figure 6 Left view of; Figure 8 is a schematic diagram of a vacuum tank in Embodiment 5 of the present invention; Fig. 9 yes Figure 8 Side view of Fig.10 is a schematic diagram of a vacuum tank in Embodiment 6 of the present invention; Fig.11 yes Fig.10 Side view of Fig.12 yes Fig.11 Schematic diagram of the flexible rubber segment; Fig.13 yes Fig.11 Schematic diagram of the state of the middle flexible rubber section after being squeezed by the push rod against the two side walls of the vacuum tank.

[0014] In the figure: 1. base; 2. reducer; 3. rotating shaft; 4. rotor; 5. stator; 6. liquid inlet pipe; 7. elastic rubber section; 8. reduction motor; 9. bottom plate; 10. machine body; 11. cam; 12. push rod; 13. intermediate wheel; 14. vacuum tank; 15. stirring blade; 16. container; 17. homogenizer; 18. sterilizer; 19. discharge pipe; 20. flexible rubber section; 21. reduction drive motor; 22. metal raised grinding disc; 23. DETAILED DESCRIPTION

[0015] The specific implementation of the present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0016] The present invention is a method for improving the thermal stability of a plant protein beverage, comprising the following process steps: 1. Preparation of stock solution: Pour plant protein drink such as Wild Plant Coffee Master into the container.

[0017] 2. Degassing: Place the stock solution in a vacuum tank with a vacuum degree of 0.01 atmospheres. Keep the vacuum pump running to ensure that the gas can be immediately pumped out. Heat the material to 70-75°C and stir at a stirring rate of 100rpm. The material temperature should be kept at 70-75°C for 30 minutes, and the stirring and vacuum pump should not stop working during this period.

[0018] 3. Homogenization and sterilization: Ensure that no air enters between the homogenizer, sterilizer and the mixing tank used for stirring. The homogenization pressure is 250-260bar. Homogenization is sufficient once. There is no requirement for the homogenization rate. UHT sterilization can be used for sterilization. The sterilization parameters are 137℃ and 10s. (The homogenizer, sterilizer and mixing tank are sealed and vacuumed) 4. Canning: Cans are made of Tetra Pak.

[0019] The original oat milk produced by Daily Box (which can be purchased directly on the market) and the No. 04 coffee powder produced by Santonban (which can be purchased directly on the market) were prepared and stirred, and the materials were heated in a water bath (the water bath heating temperature was 75℃~95℃). It was found that a certain amount of floc-like substances were produced and finally there was a slight stratification phenomenon.

[0020] Among them, the ingredient list of Daily Box Original Oat Milk is as follows: drinking water, oatmeal concentrate (drinking water, oats, vegetable oil, table salt). It can be seen that there is no stabilizer in the ingredients.

[0021] The Coffee Master plant milk from the wild plant manufacturer (which can be purchased directly on the market) and the No. 04 coffee powder from the Santonban manufacturer (which can be purchased directly on the market) were brewed and stirred, and the materials were heated in a water bath (the water bath heating temperature was 75℃~95℃). It was found that a certain amount of floc-like substances were produced and there was a slight stratification phenomenon in the end.

[0022] Among them, the ingredient list of Wild Plant Coffee Master Plant Milk is as follows: oatmeal concentrate (drinking water, oats, vegetable oil, edible salt, dipotassium hydrogen phosphate). It can be seen that there is no stabilizer in the ingredients. Example

[0023] Pour the original oat milk (available on the market) from the Daily Box manufacturer into the container. Place the container of original oat milk containing the Daily Box into a vacuum tank with a vacuum degree of 0.01 atmospheres. The vacuum pump continues to work to ensure that the exhausted gas can be immediately extracted. At the same time, heat the material to 70-75°C and stir it at a stirring rate of 100rpm. The material temperature should be kept at 70-75°C for 30 minutes, and the stirring and vacuum pump should not stop working during this period. It is also necessary to ensure that no air enters between the mixing tank and the homogenizer and sterilizer. The homogenization pressure is 250-260bar. Homogenization is sufficient once. There is no requirement for the homogenization rate. UHT sterilization can be used for sterilization, and the sterilization parameters are 137°C and 10s. Canning: Tetra Pak is used for canning. The filled product is then mixed with No. 04 coffee powder (available on the market) from the Santonban manufacturer and stirred. The product has almost no flocculation or agglomeration and no stratification occurs after standing for 20 minutes. Therefore, it can be concluded that the stability of the product has been greatly improved after degassing. Example

[0024] Pour the coffee master plant milk (available on the market) from the wild plant manufacturer into the container. Place the original oat milk container containing the daily box into the vacuum tank with a vacuum degree of 0.01 atmospheres. The vacuum pump continues to work to ensure that the exhausted gas can be immediately extracted. At the same time, heat the material to 70-75°C and stir it at a stirring rate of 100rpm. The material temperature should be kept at 70-75°C for 30 minutes, and the stirring and vacuum pump should not stop working during this period. It is also necessary to ensure that no air enters between the mixing tank and the homogenizer and sterilizer. The homogenization pressure is 250-260bar. Homogenization is sufficient once. There is no requirement for the homogenization rate. UHT sterilization can be used for sterilization, and the sterilization parameters are 137°C and 10s. Canning: Tetra Pak is used for canning. The filled product is then mixed with No. 04 coffee powder (available on the market) from the Santonban manufacturer and stirred. The product has almost no flocculation or agglomeration and no stratification occurs after standing for 20 minutes. Therefore, it can be concluded that the stability of the product has been greatly improved after degassing. Example

[0025] On June 10, 2020, the samples filled by the Pulisheng canning machine were vacuum degassed using the method of the present invention and then refilled. The thermal stability of the pilot product obtained (that is, there was no flocculation when the refilled product was mixed with coffee powder with high-temperature water) was better than that of other products. Example

[0026] The difference from the first embodiment is that Figures 1 to 7 As shown (for ease of illustration, Figure 2 The homogenizing process is carried out by a homogenizer, which includes a reducer 2 fixedly mounted on a base 1, the output shaft of the reducer 2 is fixedly connected to a rotating shaft 3, a rotor 4 is fixedly mounted on the rotating shaft 3, a stator 5 fixedly connected to the base is arranged outside the rotor, a liquid inlet pipe 6 is connected to the stator 5, and the middle section of the liquid inlet pipe is a rubber elastic section 7; a reducer motor 8 is fixedly mounted on the section of the liquid inlet pipe located beside the middle section, and a cam mechanism is connected to the output shaft of the reducer motor; and a body is connected to the stator. The cam mechanism includes a bottom plate 9 fixedly connected to a body 10, a cam 11 is rotatably mounted on the bottom plate 9, the cam is fixedly connected to the output shaft of the reducer motor, a push rod 12 is slidably mounted on the bottom plate, and an intermediate wheel 13 is rotatably mounted on the end of the push rod 12 close to the cam, and the material is sucked in by the strong centrifugal force generated by the high-speed rotation of the rotor. The process is accompanied by the combined effects of cavitation explosion, impact force, turbulence, etc., but mainly relies on shear force.

[0027] After such setting, if the influent fluctuates after the homogenizer is started, the fluctuation of the influent can be allowed due to the rubber elastic section in the middle section, which reduces the mechanical requirements for the strength of the influent pipe. After pouring the mixed and stirred liquid into the influent pipe, the cover at the influent pipe mouth can be covered, and the liquid is sucked in after the homogenizer is started. If there is fluctuation and some liquid is sprayed back, it will be allowed due to the setting of the rubber elastic section. After starting for a period of time, the reduction motor is started again, so that the cam mechanism intermittently hits the rubber elastic section to avoid some residual influent in the rubber elastic section. When cleaning, the reduction motor is started to make the cam mechanism hit the rubber elastic section in a gap to achieve effective cleaning, avoid the appearance of blind cleaning areas, and facilitate efficient cleaning of the inside of the pipeline to meet the hygienic requirements of the homogenizer. Example

[0028] The difference from the fourth embodiment is that, Figure 8 , Fig. 9 As shown, a reduction motor for mixing is fixedly arranged on the vacuum tank 14, and the output shaft of the reduction motor passes through the vacuum tank and is fixedly connected to the stirring shaft, and a stirring blade 15 for mixing is arranged on the stirring shaft; the vacuum tank is connected to a vacuum pump; the vacuum tank adopts a cylindrical shell made of nitrile rubber or chloroprene rubber or transparent soft plastic material; a container 16, a homogenizer 17 and a sterilizer 18 are arranged in sequence in the vacuum tank along the length direction of the vacuum tank; the reduction motor, the stirring shaft, the stirring blade and the vacuum tank part constitute a mixing tank; After the preparation is completed, the container is manually transferred to the homogenizer outside the vacuum tank, and the liquid in the container is poured into the liquid inlet pipe of the homogenizer for homogenization; after the homogenization is completed, the homogenized liquid is manually transferred to the disinfectant for sterilization outside the vacuum tank, and after the sterilization is completed, the vacuum pump is stopped to evacuate, and the vacuum tank is opened to transfer the sterilized liquid out of the vacuum tank; The upper part of the vacuum tank at the mixing tank (compared with other parts of the vacuum tank) uses more transparent soft plastic (so that it can be pulled upward at the beginning and end of mixing to facilitate the separation of the reduction motor and the container); the middle height part of the vacuum tank at the mixing tank and between the mixing tank and the homogenizer uses more transparent soft plastic (so that it is convenient for people to manually operate the position of the container outside the vacuum tank and move the container from the mixing tank to the homogenizer), the middle height part of the vacuum tank between the mixing tank and the homogenizer is also provided with an inwardly integrated plastic protrusion 19, and a groove 20 matched with the plastic protrusion is provided on the outer wall of the container, and the part of the vacuum tank located below the plastic protrusion is made of more transparent soft plastic (so that when a person pinches the outer wall of the vacuum tank at the plastic protrusion with one hand and pinches the part of the vacuum tank below the plastic protrusion with the other hand to rotate the container to realize pouring the liquid in the container into the liquid inlet pipe of the homogenizer); the output shaft is connected to the vacuum tank rotation seal.

[0029] With this arrangement, the vacuum environment of the mixing tank can be achieved by directly evacuating the vacuum tank, and it is ensured that no air enters between the homogenizer, the sterilizer and the mixing tank used for stirring. Due to the use of transparent soft plastic, on the one hand, it can meet the requirements of vacuuming, and on the other hand, it is convenient for manual operation of the containers, homogenizers and sterilizers located in the vacuum tank from outside the vacuum tank. More transparent soft plastic is used in the middle height part of the vacuum tank at the homogenizer and between the sterilizer and the homogenizer (to facilitate manual operation of moving the position of the container outside the vacuum tank and moving the container from the homogenizer to the sterilizer); the middle height part of the vacuum tank between the sterilizer and the homogenizer is also provided with an integrated plastic protrusion facing inward, and the part of the vacuum tank below the plastic protrusion is made of more transparent soft plastic (to facilitate pinching the outer wall of the vacuum tank at the plastic protrusion with one hand and pinching the part of the vacuum tank below the plastic protrusion with the other hand to rotate the container to pour the liquid in the container into the sterilizer); after such arrangement, only one vacuuming is required, unlike the prior art which requires not only vacuuming the vacuum tank but also sealing and vacuuming the homogenizer, the sterilizer and the mixing tank. The process is improved through structural improvement and the process complexity is reduced. Example

[0030] The difference from the fifth embodiment is that Figures 10 to 13 As shown (for ease of illustration, Fig.11 Only the homogenizer is shown), a flexible rubber section 20 is provided on the discharge pipe 19 of the homogenizer 17, a reduction drive motor 21 is fixedly arranged on the outer wall of the vacuum tank 14, and the output shaft of the reduction drive motor 21 is connected to the cam mechanism. The structure of the cam mechanism is the same as that of the cam mechanism in Example 4, so as to achieve intermittent striking (or squeezing) of the vacuum tank; a plurality of spaced metal protruding grinding discs 22 are provided on the inner wall of the flexible rubber section 20; the discharge pipe 19 is composed of three sections, two hard sections and a flexible rubber section 20 fixedly bonded between the two hard sections; when the homogenization effect is not good, the flexible rubber section 20 is cut off, the pipe openings of the two hard sections are ground flat, and a new flexible rubber section 20 (the inner wall of which is still provided with a metal protruding grinding disc 22) is re-fixed and bonded.

[0031] The advantages of high shear homogenizer are: efficient homogenization, high precision, easy operation, wide application range, large processing capacity, low noise and smooth operation; but its disadvantages include: high maintenance cost: due to its high precision and high strength working characteristics, shear blades and other parts are easy to wear and need to be replaced and maintained regularly, which increases maintenance costs; high energy consumption: although it is highly efficient, it consumes more energy during long-term operation. After the present embodiment is so arranged, the accuracy of the rotor can be reduced, and a low rotation speed can be adopted, which reduces energy consumption and adopts a more wear-resistant material, because the homogenizer composed of the rotor and the stator becomes the setting for the first homogenization process, and then the narrow gap of the discharge pipe is passed (of course, the narrow gap is achieved by the reduction drive motor driving the cam mechanism to squeeze the vacuum tank; in order to better implement this scheme, the reduction drive motor and the cam mechanism can be symmetrically arranged on the left and right side walls of the vacuum tank, and the length of the push rod 12 can be designed so that the flexible rubber section is stretched to the farthest, that is, the distance when the two side walls of the vacuum tank are squeezed most severely is reduced, so as to avoid the metal raised grinding discs 22 from abutting against each other and being worn, or to avoid the metal raised grinding discs 22 and the inner side walls of the flexible rubber section opposite to them from abutting against each other and being worn) and the metal raised grinding discs to realize the second homogenization, and only the worn metal raised grinding discs need to be replaced regularly, so that the maintenance cost is reduced (fewer parts need to be replaced, and the replaced parts are also small); through the two homogenization process steps, the effect of directly homogenizing by a high shear homogenizer in the past is achieved.

[0032] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving the thermal stability of a plant protein beverage, characterized in that: The process steps include: S1: stock solution preparation: pour the plant protein beverage into a container; S2: Degassing treatment: Place the container containing the original liquid of the plant protein beverage into a vacuum tank, and keep the vacuum pump working while heating and stirring the original liquid in the container; S3: Homogenization and sterilization: homogenization and sterilization of the stock solution; S4: Filling: Fill the original liquid treated in step S3 to obtain a plant protein beverage with improved stability.

2. A method for improving the thermal stability of a plant protein beverage according to claim 1, characterized in that: In the step S2, the vacuum degree in the vacuum tank is maintained at 0.01 atmospheres, the stock solution in the container is heated to 70-75°C and kept at 70-75°C for 30 minutes; the stirring rate is 100 rpm.

3. A method for improving the thermal stability of a plant protein beverage as claimed in claim 2, characterized in that: In the step S3, the stock solution is homogenized once, and the homogenization pressure is 250-260 bar.

4. A method for improving the thermal stability of a plant protein beverage as claimed in claim 3, characterized in that: In the step S3, UHT sterilization is used for sterilization, and the sterilization parameters are: sterilization temperature 137° C., and sterilization time 10 s.

5. A method for improving the thermal stability of a plant protein beverage as claimed in claim 1 or 4, characterized in that: The homogenizing process is carried out by a homogenizer, which includes a reducer fixedly arranged on a base, an output shaft of the reducer fixedly connected to a rotating shaft, a rotor fixedly arranged on the rotating shaft, a stator fixedly connected to the base arranged outside the rotor, a liquid inlet pipe connected to the stator, the middle section of the liquid inlet pipe is a rubber elastic section; a reduction motor is fixedly arranged on a section of the liquid inlet pipe located beside the middle section, and a cam mechanism is connected to the output shaft of the reduction motor.

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