Preparation method of low-GI konjac meal replacement powder

Abstract

The invention discloses a preparation method of low-GI konjac meal replacement powder, and belongs to the technical field of food processing. The method solves the problems that the existing low-GI meal replacement powder is non-uniform in raw material mixing, easy to lose nutritional ingredients, poor in particle forming, improper in moisture content control and the like. According to the technical scheme, the preparation method comprises the following steps: mixing konjac powder and resistant dextrin according to a mass ratio of 1: 0.5-1: 2, extruding the mixture by a twin-screw extruder at 80-120 DEG C to form a compound, and cooling and crushing the compound to 80-100 meshes; mixing the compound with inulin and soybean protein isolate according to a ratio of 100: 10: 5 to obtain a premix, and mixing the premix with vitamin mineral microcapsules according to a ratio of 100: 1; taking a 5% hydroxypropyl methyl cellulose aqueous solution as an adhesive, granulating by a fluidized bed, and drying until the water content is lower than 5%. The meal replacement powder prepared by the method is balanced in nutrition, uniform in particles, good in reconstituability and suitable for people who need to control blood sugar and pursue healthy diet.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing. More specifically, the present invention relates to a preparation method of a low-GI konjac meal replacement powder. Background Art

[0002] In modern fast-paced life, meal replacement powder, as a convenient and quick food option, has been favored by many consumers. However, there are generally some problems with the meal replacement powders currently on the market.

[0003] From the perspective of raw material mixing, the characteristic differences of different raw materials bring difficulties to uniform mixing. Some raw materials are delicate in texture, while others are coarser; some raw materials are prone to moisture absorption, while others are relatively dry. These characteristic differences make it difficult to evenly distribute various raw materials during the mixing process. Uneven mixing not only affects the appearance of the meal replacement powder but also leads to uneven distribution of nutrients. Consumers cannot obtain a stable and consistent nutrient intake when consuming it, and there will also be differences in taste, affecting the eating experience.

[0004] In terms of product shaping, there are many deficiencies in the existing shaping technologies. During the shaping process, the particle sizes are often inconsistent and the shapes are irregular. This not only affects the instant solubility of the meal replacement powder, such as it being prone to caking during brewing and difficult to fully dissolve, but also has an adverse impact on the packaging and storage of the product. Large particle differences may lead to difficulties in accurately controlling the weight during packaging, and phenomena such as stratification are also likely to occur during storage.

[0005] With the improvement of people's health awareness, low-GI (glycemic index) foods have gradually entered the public eye. Low-GI foods play an important role in maintaining stable blood sugar levels in the human body. When the human body ingests low-GI foods, the digestion and absorption rate of carbohydrates in the intestine is relatively slow, thus avoiding rapid increases and drastic fluctuations in blood sugar. This is crucial for people who need to control blood sugar, such as diabetic patients, as well as for those who pursue a healthy diet and hope to maintain a good physical condition. Stable blood sugar levels help maintain the normal metabolic functions of the body, reduce discomfort symptoms such as fatigue and dizziness caused by blood sugar fluctuations, and can also reduce the risk of chronic diseases to a certain extent, which is of great significance for people's health management. However, in the preparation process of existing low-GI meal replacement powders, due to the above-mentioned problems in raw material mixing and product shaping, it is difficult to fully exert the advantages of low-GI foods and cannot meet the needs of consumers for high-quality low-GI meal replacement powders. Summary of the Invention

[0006] The present invention provides a preparation method of a low-GI konjac meal replacement powder, which solves the problems existing in the existing low-GI meal replacement powder, such as uneven mixing of raw materials, easy loss of nutritional components, poor particle forming, improper control of moisture content, etc. The low-GI konjac meal replacement powder prepared by this preparation method has balanced nutrition, stable quality, good reconstitution performance and meets the standard of moisture content.

[0007] In order to achieve these objects and other advantages of the present invention, a preparation method of a low-GI konjac meal replacement powder is provided, including the following steps: S1. Mix konjac flour and resistant dextrin according to a mass ratio of 1:0.5 - 1:2 to obtain a mixed powder. S2. Place the mixed powder in a twin-screw extruder, and perform extrusion treatment under the condition that the extrusion temperature is 80°C - 120°C to form a complex of konjac flour and resistant dextrin. Cool the complex and crush it to a particle size of 80 mesh - 100 mesh. S3. Mix the crushed complex with inulin and soy protein isolate according to a mass ratio of 100:10:5 to obtain a premix. S4. Mix the premix with vitamin and mineral microcapsules according to a mass ratio of 100:1 to obtain an enhanced premix. S5. Place the enhanced premix in a fluidized bed granulator, use an aqueous solution of hydroxypropyl methylcellulose with a mass fraction of 5% as the binder, the spraying speed is 10 mL / min - 20 mL / min, and the inlet air temperature is 50°C - 60°C to perform fluidized bed granulation to obtain a granular meal replacement powder. S6. Dry the granular meal replacement powder at 40°C - 50°C until the moisture content is lower than 5% to obtain a low-GI konjac meal replacement powder.

[0008] Preferably, the vitamin and mineral microcapsules contain: 10% - 20% by mass of compound vitamins, 15% - 25% of minerals, and 55% - 75% of wall materials; wherein, the compound vitamins include: vitamins A, D, E, B1, B2, B6, B12, folic acid and calcium pantothenate; the minerals include calcium carbonate, ferrous sulfate, zinc gluconate, sodium selenite; the wall materials are composed of arabic gum and β-cyclodextrin according to a mass ratio of 1:1 - 1:2. The preparation method of the vitamin and mineral microcapsules includes: Disperse the compound vitamins and minerals in a wall material solution at 40°C - 50°C, homogenize and then spray dry, the inlet air temperature is 150°C - 160°C, and the outlet air temperature is 70°C - 80°C to obtain vitamin and mineral microcapsules with a particle size of 50 μm - 100 μm.

[0009] Preferably, in the vitamin and mineral microcapsules, 0.5% - 1% by mass of phospholipids is also added as an emulsifier.

[0010] Preferably, in S2, the twin-screw extruder adopts a segmented temperature control mode, wherein the temperature of the feeding section is 80°C - 90°C, the temperature of the kneading section is 100°C - 110°C, the temperature of the discharging section is 110°C - 120°C, and the screw speed is increased by 20% - 30% in the kneading section compared to the feeding section.

[0011] Preferably, the composite is cooled and crushed to a particle size of 80 - 100 mesh, specifically: S201. Gradually cool the extruded composite through a screw conveyor cooler: The first stage: 80°C → 50°C, cooling rate 10°C / min, time 3 min; The second stage: 50°C → 25°C, cooling rate 5°C / min, time 5 min; The third stage: 25°C → 5°C, cooling rate 2°C / min, time 10 min; S202. Feed the cooled composite into a turbo-type ultrafine mill and crush it under nitrogen protection. The control parameters are: crushing pressure 0.6 - 0.8 MPa, rotor speed 8000 - 10000 rpm, feeding speed 8 - 12 kg / h, and the temperature in the crushing chamber ≤ 35°C; S203. Use an ultrasonic vibration screening system to classify the crushed product: The first-stage screen mesh is 100 mesh, the second-stage screen mesh is 80 mesh, vibration frequency 28 - 32 kHz, and amplitude 0.5 - 1 mm; S204. Collect the material between 80 - 100 mesh, and dry it by pulsed air flow to make the moisture content ≤ 5%.

[0012] Preferably, during the gradient cooling process of S201, dehumidified air with a dew point ≤ -15°C is introduced into the screw conveyor cooler at a flow rate of 2 - 3 m³ / min to make the water activity Aw of the composite at the cooling end ≤ 0.35; In S202, the surface of the rotor of the turbo-type ultrafine mill is coated with a polytetrafluoroethylene wear-resistant coating with a thickness of 50 - 80 μm to reduce the adhesion of konjac powder.

[0013] Preferably, S3 specifically includes: S301. Accurately weigh each component according to the mass ratio: composite: inulin: soy protein isolate = 100:10:5; S302. Premix inulin and part of the composite at a mass ratio of 1:1 for 3 - 5 minutes to form a primary mixture; S303. Add the remaining composite in two portions with an interval of 2 minutes each, and mix for 5 minutes; S304. Finally, add soy protein isolate in the form of atomized powder spraying, with a powder spraying rate of 0.5 - 1.0 g / s, while keeping the mixing container stirred at a low speed of 8 - 10 r / min, and the total mixing time is 15 - 20 minutes.

[0014] Preferably, in S302, when inulin is premixed with part of the complex, 0.1 - 0.3% of silicon dioxide based on the mass of inulin is added as a flow aid, and after premixing, it is left standing for 5 minutes to eliminate static electricity; In S304, when atomized powder spraying, a lecithin ethanol solution accounting for 0.5 - 1.0% of the mass of soy protein isolate is sprayed synchronously, with a concentration of 10% and a liquid spraying rate of 0.2 - 0.3 mL / s.

[0015] Preferably, S4 specifically includes: S401. Weigh each component accurately according to the mass ratio: premix: vitamin and mineral microcapsule = 100:1; S402. Place the vitamin and mineral microcapsules in a fluidized bed mixer, introduce dry air with a relative humidity ≤ 30% at a flow rate of 1 - 1.5 m³ / min to pre-disperse the vitamin and mineral microcapsules for 5 - 8 minutes; S403. Add the premix to the fluidized bed in three times, with an interval of 3 minutes each time, and control the mixing speed at 15 - 20 r / min, and the total mixing time is 12 - 15 minutes; S404. During the mixing process, pause the mixing every 3 minutes and let it stand for 1 minute to eliminate the accumulation of static electricity.

[0016] Preferably, in S402, 0.03 - 0.08% of nano-silica aerosol with a particle size of 20 - 50 nm based on the mass of the vitamin and mineral microcapsules is added to the dry air to enhance the fluidity and anti-adhesion of the vitamin and mineral microcapsules; In S403, each time the premix is added, a sodium alginate solution accounting for 0.02 - 0.05% of the mass of the premix is sprayed synchronously, with a concentration of 1% and a liquid spraying rate of 0.1 - 0.2 mL / s.

[0017] The present invention has at least the following beneficial effects: First, through specific raw material ratios and processing procedures, raw materials such as konjac flour, resistant dextrin, inulin, and soy protein isolate can be fully blended to ensure the uniform distribution of nutritional components. Appropriate granulation and drying conditions can make the meal replacement powder have uniform particles, good instant solubility, meet the moisture content standard, extend the shelf life, and provide consumers with a low-GI konjac meal replacement powder with balanced nutrition, stable quality, and convenient consumption. The clear composition and preparation method of vitamin and mineral microcapsules can effectively protect the compound vitamins and minerals and reduce their oxidation and deliquescence during processing and storage. Appropriate wall materials and spray drying technology make the microcapsule particle size uniform and have good dispersibility in the meal replacement powder, ensuring that consumers can intake comprehensive and stable nutritional components and enhancing the nutritional value of the meal replacement powder. Adding phospholipids as emulsifiers can reduce the interfacial tension between the components in the microcapsules and prevent stratification and agglomeration between the compound vitamins, minerals, and wall materials. This makes the vitamin and mineral microcapsules more easily dispersed and uniform in the meal replacement powder, effectively improving the stability and bioavailability of the nutritional fortifier and further ensuring the nutritional quality of the meal replacement powder.

[0018] Second, the twin-screw extruder controls the temperature in sections and adjusts the screw speed, enabling the raw materials to fully react at different stages. The low temperature in the feeding section is conducive to material transportation, and the appropriate temperature and increased screw speed in the kneading section promote the physical and chemical reactions between the raw materials. The high temperature in the discharging section ensures the formation of the composite. Precise process control can retain the nutritional components of the raw materials, improve the taste and quality of the meal replacement powder, and increase the market competitiveness of the product. The precise gradient cooling, crushing, screening, and drying processes can effectively control the particle size and moisture content of the composite. Gradient cooling avoids sudden temperature changes affecting the product quality, ultrafine crushing and precise screening ensure uniform powder particle size, and pulsed air drying controls the moisture to ensure that the meal replacement powder has a delicate texture, good solubility, and improves the stability and quality uniformity of the product. Introducing dehumidified air to reduce the water activity can prevent the composite from absorbing moisture and deteriorating during the cooling process and extend the product shelf life. Coating the rotor surface with a polytetrafluoroethylene wear-resistant coating reduces the adhesion of konjac powder, lowers the equipment cleaning frequency, improves production efficiency, and at the same time avoids product quality fluctuations caused by powder adhesion, ensuring stable product quality.

[0019] Third, the precise weighing and step-by-step mixing method can fully consider the characteristics of different raw materials and make inulin, soy protein isolate, and the composite evenly mixed. Steps such as premixing, multiple additions, and low-speed stirring effectively avoid raw material agglomeration, ensure the uniform distribution of the nutritional components in the meal replacement powder, and improve the quality and taste consistency of the product. Adding silica as a flow aid can improve the fluidity of inulin, eliminate static electricity, and prevent it from caking during premixing. Synchronously spraying the lecithin ethanol solution can make the soy protein isolate disperse more evenly during atomized powder spraying, further improving the mixing effect, ensuring stable meal replacement powder quality, and providing consumers with a better-quality product.

[0020] Fourth, specific weighing, pre-dispersion, multiple mixing, and anti-static steps can ensure sufficient and uniform mixing of the premix and vitamin and mineral microcapsules. Pre-dispersion preliminarily disperses the microcapsules. Adding the premix multiple times and controlling the mixing speed avoid uneven mixing. Eliminating static electricity accumulation prevents material adsorption, ensuring the uniformity and stability of the nutritional components of the meal replacement powder. Adding nano-silica aerosol enhances the fluidity and anti-adhesion of the vitamin and mineral microcapsules, making them more easily dispersed during mixing. Synchronously spraying the sodium alginate solution improves the dispersion of the premix and further optimizes the mixing effect. This makes the nutritional distribution of the meal replacement powder more uniform, improving the quality and nutritional value of the product.

[0021] Other advantages, objectives, and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic flow chart of the preparation method of the low-GI konjac meal replacement powder of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following further describes the present invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0024] It should be understood that terms such as "having", "comprising", and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0025] As Figure 1 shown, the embodiment of the present invention provides a preparation method of a low-GI konjac meal replacement powder, including the following steps: S1. Mix konjac flour and resistant dextrin in a mass ratio of 1:0.5 - 1:2 to obtain a mixed powder; S2. Place the mixed powder in a twin-screw extruder and perform extrusion treatment at an extrusion temperature of 80°C - 120°C to form a complex of konjac flour and resistant dextrin. Cool the complex and crush it to a particle size of 80 - 100 mesh; S3. Mix the crushed complex with inulin and soy protein isolate in a mass ratio of 100:10:5 to obtain a premix; S4. Mix the premix with vitamin and mineral microcapsules in a mass ratio of 100:1 to obtain an enhanced premix; S5. Place the enhanced premix in a fluidized bed granulator, use an aqueous solution of hydroxypropyl methylcellulose with a mass fraction of 5% as the binder, the spraying speed is 10 mL / min - 20 mL / min, and the inlet air temperature is 50°C - 60°C for fluidized bed granulation to obtain granular meal replacement powder; S6. Dry the granular meal replacement powder at 40°C - 50°C until the moisture content is less than 5% to obtain a low-GI konjac meal replacement powder.

[0026] In the above embodiments, in step S1, resistant dextrin, as a low-GI adjuvant, can balance the high viscosity of konjac flour and improve the fluidity of subsequent processing. By precisely controlling the ratio of konjac flour to resistant dextrin, the complementary functions of raw materials are realized, retaining both the high dietary fiber characteristics of konjac and using resistant dextrin to improve the powder fluidity, providing a uniform raw material basis for the subsequent extrusion process. In step S2, twin-screw extrusion promotes the formation of a stable complex between konjac flour and resistant dextrin molecules, significantly reducing the glycemic index of the product, i.e., the GI value. Cooling and grinding after extrusion can control the particle fineness, ensure solubility and delicate taste, and avoid the destruction of nutrients caused by high temperature. In step S3, the complex is mixed with inulin and soy protein isolate at a ratio of 100:10:5. Inulin supplements the prebiotic function, and soy protein enhances the amino acid balance. The three work together to enhance the nutritional value of the meal replacement powder; precise ratio ensures uniform mixing and avoids caking or ingredient segregation. In step S4, the vitamin and mineral microcapsules protect sensitive nutrients through the wall material, significantly improving the stability during processing and storage. The microencapsulation technology avoids direct contact between minerals (such as iron and zinc) and other components, preventing oxidation or odor generation. In step S5, the combination of hydroxypropyl methylcellulose binder and spraying speed forms particles with high sphericity and moderate strength. Low-temperature air inlet maintains the activity of thermosensitive components, while ensuring rapid particle formation and excellent dispersibility during brewing without caking. In step S6, gentle drying at 40 - 50°C until the moisture content ≤ 5% effectively extends the shelf life while retaining the low-GI characteristics of the product. Low water activity inhibits the growth of microorganisms and ensures food safety. In summary, the full-process process design takes into account both functionality and processing feasibility. The final product has both low GI, high nutritional retention, and excellent brewing properties. The parameters of each step are synergistically optimized, suitable for large-scale production, and meet the market demand for healthy and convenient meal replacement powders.

[0027] Konjac flour and resistant dextrin can be mixed in a mass ratio of 1:0.5 to 1:2, and the specific ratio can be selected as 1:0.8, 1:1 or 1:1.5. The mixing equipment can use a three-dimensional motion mixer or a V-type mixer, and the mixing time can be controlled within 10 - 20 minutes. The mixing container can be made of stainless steel, and the volume can be selected from 50L to 500L according to the production scale. During the pretreatment of raw materials, the konjac flour can be sieved through an 80-mesh sieve, and the resistant dextrin can be sieved through a 100-mesh sieve to ensure uniform particle size of the raw materials. The environmental humidity can be controlled below 40% and the temperature can be around 25°C during the mixing process. The uniformity of the mixed material needs to be detected, and near-infrared spectroscopy can be used for rapid detection. The twin-screw extruder can be of co-rotating type, and the screw diameter can be selected from 35mm to 75mm. The extrusion temperature can be controlled in sections: the feeding section is 80 - 90°C, the kneading section is 100 - 110°C, and the discharging section is 110 - 120°C. The specific temperature settings can be selected as 85°C for the feeding section, 105°C for the kneading section, and 115°C for the discharging section. The screw speed can be set at 100 - 150rpm in the feeding section and increased by 20 - 30% in the kneading section, that is, 120 - 195rpm. The die head aperture of the extruder can be selected from 3 - 5mm, and the length-diameter ratio is 25:1 to 40:1. The motor load can be monitored during the extrusion process and controlled within the range of 70 - 85% of the rated power. The extruded composite can be cooled in a gradient manner through a screw conveyor cooler. The first stage is to cool from 80°C to 50°C, with a cooling rate of 10°C / min and a time of 3 minutes; the second stage is to cool from 50°C to 25°C, with a cooling rate of 5°C / min and a time of 5 minutes; the third stage is to cool from 25°C to 5°C, with a cooling rate of 2°C / min and a time of 10 minutes. The cooled material can be pulverized using a vortex ultrafine pulverizer, with a pulverizing pressure of 0.6 - 0.8MPa and a rotor speed of 8000 - 10000rpm. The pulverized material is classified through an ultrasonic vibrating screen, with a first-stage sieve mesh of 100 meshes, a second-stage sieve mesh of 80 meshes, and a vibration frequency of 28 - 32kHz. The material between 80 - 100 meshes is collected, and the moisture content is controlled below 4%. The pulverized composite, inulin, and soy protein isolate can be mixed in a mass ratio of 100:10:5. The mixing equipment can use a conical mixer, and the mixing time is 15 - 20 minutes. Vitamin and mineral microcapsules are added at 1% of the premix mass and mixed using a fluidized bed mixer for 12 - 15 minutes. The granulation process can use a fluidized bed granulator, with a binder being a 5% aqueous solution of hydroxypropyl methylcellulose, a spraying speed of 10 - 20mL / min, and an inlet air temperature of 50 - 60°C. Final drying is carried out using a hot air circulation drying oven at a temperature of 40 - 50°C until the moisture content is lower than 5%.

[0028] In one specific embodiment, the vitamin and mineral microcapsule comprises: 10%-20% by mass of a compound vitamin, 15%-25% of a mineral, and 55%-75% of a wall material; wherein, the compound vitamin includes: vitamins A, D, E, B1, B2, B6, B12, folic acid, and calcium pantothenate; the mineral includes calcium carbonate, ferrous sulfate, zinc gluconate, and sodium selenite; the wall material is composed of gum arabic and β-cyclodextrin in a mass ratio of 1:1 - 1:2; The preparation method of the vitamin and mineral microcapsule includes: Disperse the compound vitamin and the mineral in a wall material solution at 40°C - 50°C, homogenize and then spray dry, with an inlet air temperature of 150°C - 160°C and an outlet air temperature of 70°C - 80°C, to obtain vitamin and mineral microcapsules with a particle size of 50μm - 100μm.

[0029] Wherein, in the vitamin and mineral microcapsule, 0.5%-1% of phospholipid based on the total mass of the vitamin and mineral microcapsule is further added as an emulsifier.

[0030] In the above embodiment, the composite wall material formed by gum arabic and β-cyclodextrin has both film-forming property and embedding ability, significantly reducing the oxidative loss of vitamins (such as B12, folic acid) and the deliquescence risk of minerals (such as ferrous sulfate). The spray drying uses an inlet air temperature of 150 - 160°C and an outlet air temperature of 70 - 80°C, avoiding the destruction of heat-sensitive components by high temperature while drying quickly. Adding 0.5%-1% of phospholipid can reduce the oil-water interfacial tension, making the fat-soluble vitamins (A, D, E) evenly dispersed in the wall material and improving the intestinal absorption rate. The particle size range of 50 - 100μm of the microcapsules ensures uniform dispersion in the meal replacement powder, avoiding local overnutrition or undernutrition. The microcapsule structure effectively isolates the chemical reaction between minerals such as sodium selenite and other components, preventing the generation of abnormal odors or color changes during processing. The hydrophobicity of the wall material and the film-forming property of gum arabic work together to make the nutrient retention rate of the microcapsules still ≥90% after 12 months of storage. β-cyclodextrin embeds minerals such as iron and zinc, significantly reducing the metallic taste and improving the taste acceptance. Microencapsulation avoids the direct contact between vitamins and minerals, such as the reaction between vitamin C and iron ions, maintaining the activity of the components. This microcapsule technology realizes the efficient protection, controlled release, and product quality improvement of nutritional fortifiers through the coordinated design of ingredient ratios, process parameters, and functional aids, providing a stable nutritional guarantee for low-GI meal replacement powders.

[0031] The vitamin and mineral microcapsules may contain 10% to 20% by mass of compound vitamins, 15% to 25% of minerals, and 55% to 75% of wall materials. The compound vitamins may include vitamin A, D, E, B1, B2, B6, B12, folic acid, and calcium pantothenate. Exemplarily, vitamin A: 2.0%; vitamin D3: 0.2%; vitamin E: 6.5%; vitamin B1: 1.5%; vitamin B2: 1.3%; vitamin B6: 1.3%; vitamin B12: 0.08%; folic acid: 1.0%; calcium pantothenate: 4.0%; carrier: 82.12%. The minerals may include calcium carbonate, ferrous sulfate, zinc gluconate, and sodium selenite. The wall materials may be composed of gum arabic and β-cyclodextrin at a mass ratio of 1:1 to 1:2.

[0032] The mass fraction of the compound vitamins can be selected as 12%, 15%, or 18%. The mass fraction of the minerals can be selected as 18%, 20%, or 22%. The mass fraction of the wall materials can be selected as 60%, 65%, or 70%. The mass ratio of gum arabic to β-cyclodextrin can be selected as 1:1, 1:1.5, or 1:2. The compound vitamins and minerals are dispersed in the wall material solution at 40°C to 50°C, and after homogenization, they are spray-dried. The inlet air temperature for spray drying can be selected as 150°C, 155°C, or 160°C, and the outlet air temperature can be selected as 70°C, 75°C, or 80°C. The particle size of the prepared microcapsules can be 50μm, 75μm, or 100μm. The homogenization equipment can use a high-shear disperser, and the spray drying equipment can use a centrifugal spray drying tower. The wall material solution can be prepared in a stainless steel stirring tank with the temperature controlled at about 45°C. The rotation speed of the atomizer for spray drying can be set at 10,000 rpm to 15,000 rpm to ensure uniform particle size of the microcapsules. In the vitamin and mineral microcapsules, 0.5% to 1% by mass of phospholipids can be added as an emulsifier. The addition amount of phospholipids can be selected as 0.6%, 0.8%, or 1%. The phospholipids can use soy lecithin or sunflower lecithin, which are dissolved in ethanol and then added to the wall material solution. The addition of phospholipids can be carried out before homogenization and mixed evenly with the wall material solution. The concentration of the ethanol solution can be selected as 10%, and the addition rate is controlled at 0.2 mL / s to 0.3 mL / s. The mixed solution needs to be stirred at 40°C to 50°C for 10 minutes to ensure the full dispersion of phospholipids. It can ensure the stability of vitamins and minerals during processing and storage, reducing the risks of oxidation and deliquescence. The control of the particle size of the microcapsules is beneficial to the uniform dispersion in the meal replacement powder and improves the bioavailability of nutrients. The addition of phospholipids further enhances the emulsifying performance of the microcapsules, preventing ingredient stratification or agglomeration. The overall process is feasible and suitable for industrial production.

[0033] In one specific embodiment, in S2, the twin-screw extruder adopts a segmented temperature control mode. Among them, the temperature of the feeding section is 80°C - 90°C, the temperature of the mixing section is 100°C - 110°C, the temperature of the discharging section is 110°C - 120°C, and the screw speed is increased by 20% - 30% in the mixing section compared with the feeding section.

[0034] Among them, cooling the composite and crushing it to a particle size of 80 - 100 mesh specifically includes: S201. Gradually cool the composite after extrusion treatment through a screw conveyor cooler: The first stage: 80°C → 50°C, the cooling rate is 10°C / min, and the time is 3 min; The second stage: 50°C → 25°C, the cooling rate is 5°C / min, and the time is 5 min; The third stage: 25°C → 5°C, the cooling rate is 2°C / min, and the time is 10 min; S202. Put the cooled composite into a turbo-type ultrafine mill and crush it under nitrogen protection. The controlled parameters are: the crushing pressure is 0.6 - 0.8 MPa, the rotor speed is 8000 - 10000 rpm, the feeding speed is 8 - 12 kg / h, and the temperature of the crushing chamber is ≤ 35°C; S203. Use an ultrasonic vibration screening system to classify the crushed product: The first-stage sieve mesh is 100 mesh, the second-stage sieve mesh is 80 mesh, the vibration frequency is 28 - 32 kHz, and the amplitude is 0.5 - 1 mm; S204. Collect the material between 80 - 100 mesh, and dry it by pulsed pneumatic drying to make the moisture content ≤ 5%.

[0035] Further, during the gradient cooling process of S201, dehumidified air with a dew point ≤ -15°C is introduced into the screw conveyor cooler at a flow rate of 2 - 3 m³ / min to make the water activity Aw of the cooling end point of the composite ≤ 0.35; In S202, the surface of the rotor of the turbo-type ultrafine mill is coated with a polytetrafluoroethylene wear-resistant coating with a thickness of 50 - 80 μm to reduce the adhesion of konjac powder.

[0036] In the above embodiments, through the gradient heating of the feeding section (80 - 90 °C) → kneading section (100 - 110 °C) → discharging section (110 - 120 °C), the molecular crosslinking of konjac glucomannan and resistant dextrin is promoted, forming a stable complex structure, which reduces the GI value of the final product by 15 - 20%. Increasing the rotation speed of the kneading section by 20 - 30% enhances the shear force, making the raw material mixture more uniform and avoiding the destruction of nutrients caused by local overheating. The three-stage gradient cooling (80 °C → 50 °C → 25 °C → 5 °C) is adopted, and the cooling rate is gradually reduced from 10 °C / min to 2 °C / min to prevent the rupture of konjac polysaccharide molecular chains caused by sudden temperature changes and retain its hydration ability. Through the three-stage precise temperature control (80 °C → 5 °C), it is avoided that the complex agglomerates due to sudden cooling and moisture absorption, while retaining the gel properties of resistant dextrin. Combined with dehumidified air with a dew point ≤ -15 °C, the water activity Aw at the end of cooling ≤ 0.35, inhibiting the microbial activity and extending the shelf life of the raw material semi-finished products. Combining the control of water activity with dehumidified air inhibits the wall sticking problem during subsequent grinding from the source. Grinding is carried out in a nitrogen environment, effectively preventing the oxidation of polyphenolic substances in konjac powder. The vortex grinding combined with an inert gas environment prevents the oxidation and degradation of konjac polysaccharide, and the particle size distribution is concentrated. Through a grinding pressure of 0.6 - 0.8 MPa and a rotor speed of 8000 - 10000 rpm, a uniform powder with a mesh size of 80 - 100 is obtained, ensuring the process stability of subsequent mixing and granulation. The sieve fraction between 80 - 100 meshes (100 meshes ≈ 150 μm, 80 meshes ≈ 180 μm) is specifically collected, and the particles with a size of 150 - 180 μm have the best specific surface area. If the particle size is too fine, such as less than 150 μm, it is easy to cause agglomeration, such as konjac glucomannan rapidly swelling into a gel block when encountering water. If the particle size is too coarse, such as greater than 180 μm, the sedimentation is too fast, and the 80 - 100 mesh particles can be evenly dispersed in water for 5 - 10 minutes. This particle size range maximizes the sustained-release effect of konjac fiber and resistant dextrin. And particles larger than 180 μm have an obvious rough feeling in the oral cavity, while particles with a size of 150 - 180 μm continuously release flavor substances, such as added mineral ions, in the saliva environment, improving the sensory quality. The 80-mesh screening uses 28 kHz, and the 100-mesh screening uses 30 kHz, with the amplitude adjusted accordingly to 0.5 - 1 mm.

[0037] In one specific embodiment, the S3 specifically includes: S301. Weigh each component accurately according to the mass ratio: complex: inulin: soy protein isolate = 100:10:5; S302. Premix inulin and part of the complex, with a mass ratio of 1:1, for 3 - 5 minutes to form a primary mixture; S303. Add the remaining complex in two portions, with an interval of 2 minutes each time, and mix for 5 minutes; S304. Finally, add soy protein isolate in the form of atomized powder spraying, with a powder spraying rate of 0.5 - 1.0 g / s, while keeping the mixing container stirred at a low speed of 8 - 10 r / min, and the total mixing time is 15 - 20 minutes.

[0038] Further, in S302, when inulin is premixed with part of the complex, 0.1 - 0.3% of silica based on the mass of inulin is added as a flow aid, and after premixing, it is left standing for 5 minutes to eliminate static electricity; In S304, when atomized powder spraying, a lecithin ethanol solution accounting for 0.5 - 1.0% of the mass of soy protein isolate is sprayed synchronously, with a concentration of 10% and a liquid spraying rate of 0.2 - 0.3 mL / s.

[0039] In the above - mentioned embodiment, through the step - by - step mixing process design, first premix inulin with part of the complex, then add the remaining complex in batches, and finally add soy protein by atomization, effectively solving the mixing problem of raw materials with different densities and particle sizes. This progressive mixing method significantly improves the distribution uniformity of each component and avoids the component segregation problem common in traditional mixing processes. Adding an appropriate amount of flow aid and setting a standing link in the premixing stage effectively eliminates the electrostatic adsorption phenomenon between raw materials. This measure significantly reduces the tendency of powder agglomeration, ensures good fluidity of the material in subsequent processes, and creates favorable conditions for uniform mixing. Using atomized powder spraying technology in combination with a surfactant solution enables soy protein isolate to be evenly dispersed in the mixing system. This method not only avoids the aggregation of protein particles but also improves the compatibility between the protein and other components, enhancing the dissolution performance of the final product. The step - by - step mixing process avoids the direct contact between heat - sensitive components (such as inulin) and high - temperature materials, effectively protecting the activity of functional components. At the same time, the mild mixing conditions maximize the retention of the natural structure and functional characteristics of soy protein. Standardized process parameters and step - by - step operation design ensure the consistency between different production batches. This highly controllable mixing method provides a reliable guarantee for large - scale production, reducing the risk of product quality fluctuations. Compared with traditional mixing processes, this step - by - step mixing method improves production efficiency while ensuring mixing quality through optimized process design, realizes reasonable control of energy consumption, and reflects good economic benefits. This mixing process shows significant advantages in the homogenization of multi - component systems through the synergistic effect of physical and chemical means, provides an ideal material basis for subsequent processing procedures, and ultimately ensures the excellent quality and stable performance of the product.

[0040] In one specific embodiment, S4 specifically includes: S401. Weigh each component accurately according to the mass ratio: premix: vitamin - mineral microcapsule = 100:1; S402. Place the vitamin and mineral microcapsules in a fluidized bed mixer, and introduce dry air with a relative humidity ≤ 30% at a flow rate of 1 - 1.5 m³ / min to pre-disperse the vitamin and mineral microcapsules for 5 - 8 minutes; S403. Add the premix to the fluidized bed in three batches, with an interval of 3 minutes between each addition. Control the mixing speed at 15 - 20 r / min, and the total mixing time is 12 - 15 minutes; S404. During the mixing process, pause the mixing every 3 minutes and let it stand for 1 minute to eliminate the accumulation of static electricity.

[0041] Further, in S402, add nano-silica aerosol accounting for 0.03 - 0.08% of the mass of the vitamin and mineral microcapsules to the dry air. The particle size is 20 - 50 nm to enhance the fluidity and anti-adhesion of the vitamin and mineral microcapsules; In specific implementation, nano-silica can be premixed with anhydrous glucose at a ratio of 1:10, and then added to the dry air (flow rate 1.2 m³ / min) at 0.3% of the total mass of the vitamin and mineral microcapsules. After being dispersed by an ultrasonic nebulizer, it is introduced into the fluidized bed mixer.

[0042] In S403, when adding the premix each time, simultaneously spray in a sodium alginate solution accounting for 0.02 - 0.05% of the mass of the premix, with a concentration of 1% and a spraying rate of 0.1 - 0.2 mL / s.

[0043] In the above embodiments, the microcapsules are pre-dispersed by a fluidized bed mixer and combined with low-humidity drying air to effectively prevent the microcapsules from absorbing moisture and caking, ensuring their initial dispersed state in the mixing system. Adding nanoscale silica in the drying air significantly improves the surface fluidity of the microcapsules, reducing particle adhesion and agglomeration. The method of adding the premix in three batches, combined with precise control of the mixing speed, realizes the progressive and uniform mixing of the microcapsules and the premix, avoiding local over-concentration or stratification. Regularly pausing the mixing and allowing it to stand effectively eliminates particle aggregation caused by static electricity, ensuring mixing uniformity. When adding the premix each time, a sodium alginate solution is sprayed synchronously to form a protective film, which not only prevents the microcapsules from being damaged but also promotes the combination of different components. Sodium alginate forms a hydrophilic layer on the particle surface, improving the wettability and dispersion stability of the overall system. Strictly controlling the air humidity, flow rate, and mixing parameters ensures the consistency of products in different batches and reduces the influence of environmental factors on the mixing effect. The dual effects of nanoscale silica and sodium alginate significantly reduce the adhesion of materials to the inner wall of the equipment, improving production efficiency and product yield. Gentle mixing conditions and precise parameter control minimize mechanical damage to the microcapsule structure, ensuring the stability of vitamins and minerals. Ensure the uniform distribution of micronutrients in the final product, avoiding local excess or deficiency. In summary, through the synergistic effects of physical dispersion, chemical modification, and precise control, the perfect combination of micronutrient fortifiers and the main ingredients is achieved, providing a uniform and stable material basis for the subsequent granulation process, while ensuring the integrity of nutrients and product quality.

[0044] Specific examples will be given below for illustration.

[0045] Example 1: Raw material preparation: Konjac glucomannan: 10 kg; Resistant dextrin: 10 kg; Inulin: 1 kg; Soy protein isolate: 0.5 kg; Vitamin and mineral microcapsules: 0.1 kg; Hydroxypropyl methylcellulose: appropriate amount (prepared into a 5% aqueous solution).

[0046] Preparation steps: S110. Basic mixing: Put 10 kg of konjac glucomannan and 10 kg of resistant dextrin into a mixer according to a mass ratio of 1:1 and mix for 15 minutes until uniform; S120. Twin-screw extrusion: Add the mixed powder into a twin-screw extruder, set the extrusion temperature at 100 °C, and obtain a konjac-resistant dextrin complex through extrusion treatment.

[0047] S130. Cooling and pulverizing: Cool the extrusion product to room temperature and pulverize it to a fineness of 80 - 100 mesh.

[0048] S140. Preparation of premix: Take 10 kg of the pulverized complex and mix it with 1 kg of inulin and 0.5 kg of soy protein, and stir for 15 minutes until uniform.

[0049] S150, Nutritional fortification: Mix the premix with 0.1 kg of vitamin and mineral microcapsules and stir for 10 minutes until evenly dispersed.

[0050] S160, Fluidized bed granulation: Add the fortified premix to a fluidized bed granulator, spray in a 5% hydroxypropyl methylcellulose solution (15 mL / min), and control the inlet air temperature at 55 °C for granulation.

[0051] S170, Drying and packaging: Dry the granular product at 45 °C until the moisture content ≤ 5%.

[0052] Properties of the prepared product: Uniform particles, good instant solubility, low GI property, uniform distribution of nutritional components, and a shelf life of up to 12 months.

[0053] Data analysis of Example 1: 1. Basic physical property tests: Particle size distribution: The proportion of 80 - 100 mesh is 92%, measured using a laser particle size analyzer. Moisture content: 4.8%, measured using the constant weight method at 105 °C (GB 5009.3). Instant solubility time: 35 ± 3 seconds, observed by stirring in 200 mL of water at 60 °C. Bulk density: 0.52 g / cm³, measured using the standard graduated cylinder method.

[0054] 2. Nutritional component analysis: Content per 100 g: Dietary fiber: 28.6 g, measured using the enzymatic method (GB 5009.88); Protein: 15.2 g, measured using the Kjeldahl method. Retention rate of vitamin B12: 89%, measured using HPLC method (GB 5009.217).

[0055] 3. Functional property tests: GI value (glucose = 100): 48 ± 2; Water absorption and swelling ratio (at 20 °C): 5.8 times; Shelf life (at room temperature), no caking for 12 months.

[0056] Example 2: Raw material preparation: Konjac flour: 10 kg; Resistant dextrin: 10 kg; Inulin: 1 kg; Soy protein isolate: 0.5 kg; Vitamin and mineral microcapsules: 0.1 kg, specifically: Compound vitamins: 15% (including A, D, E, B group, etc.), Minerals: 20% (calcium carbonate, ferrous sulfate, etc.), Wall material: 65% (arabic gum:β - cyclodextrin = 1:1), Phospholipid: 0.8%; Hydroxypropyl methylcellulose: appropriate amount (prepared into a 5% aqueous solution).

[0057] Preparation steps: S210, Basic mixing: Put 10 kg of konjac flour and 10 kg of resistant dextrin into a three - dimensional mixer and mix for 15 minutes until uniform according to a mass ratio of 1:1.

[0058] S220, Twin-screw extrusion: The mixed powder is added to a twin-screw extruder, and the extrusion temperature is set at 100 °C to form a konjac-resistant dextrin complex.

[0059] S230, Cooling and pulverizing: The extruded product is cooled to room temperature and pulverized to 80 - 100 mesh. S240, Preparation of premix: Take 10 kg of the pulverized complex and mix it with 1 kg of inulin and 0.5 kg of soy protein. Stir for 15 minutes according to the mass ratio of 100:10:5.

[0060] S250, Nutritional fortification: Mix the premix with 0.1 kg of vitamin and mineral microcapsules and stir for 10 minutes according to the mass ratio of 100:1.

[0061] Method for preparing microcapsules: Disperse vitamins and minerals in a wall material solution at 45 °C, homogenize and then spray dry (inlet air temperature 155 °C, outlet air temperature 75 °C) to obtain 80-μm microcapsules, and add 0.8% phospholipid as an emulsifier.

[0062] S260, Fluidized bed granulation: Add the fortified premix to a fluidized bed granulator, spray in a 5% hydroxypropyl methylcellulose solution (15 mL / min), and control the inlet air temperature at 55 °C for granulation.

[0063] S270, Drying and packaging: Dry the granular product at 45 °C until the moisture content ≤ 5%. Product characteristics: Particle uniformity: Pass through an 80 - 100 mesh sieve; Dispersion property: Completely dispersed within 30 seconds; Integrity of microcapsules: No breakage observed under a microscope; GI value: ≤ 45 (referenced to glucose).

[0064] Data analysis of Example 2: 1. Microcapsule performance test: Microcapsule embedding rate: 93.5%, using ultraviolet spectrophotometry; Particle size distribution: D50 = 82 μm (90% within 50 - 100 μm), using laser diffraction method; Iron element oxidation rate (after 3 months): 8.2%, using atomic absorption spectrometry.

[0065] 2. Comparison of product characteristics, as shown in Table 1: Table 1 Characteristic Example 2 Conventional meal replacement powder Retention rate of vitamin E (after processing) 91% 68% Mineral dissolution rate (2h) 35% 62% Sensory score (0 - 10 points) 8.7 6.2 3. Accelerated stability test: Change after one month: Vitamin C loss rate 12%; Water activity Aw changes from 0.28 to 0.31; No visible caking.

[0066] It can be obtained that microencapsulation improves the processing retention rate of thermosensitive nutrients (vitamin B group) by more than 25%; through in vitro digestion experiments, the glucose release rate of the product of Example 2 is reduced by 42% (compared with ordinary konjac flour); electron microscope observation shows that the microcapsules still maintain a complete structure after 3 months of storage.

[0067] Example 3: Raw material preparation: Konjac refined flour: 10 kg; Resistant dextrin: 10 kg; Inulin: 1 kg; Soy protein isolate: 0.5 kg; Vitamin and mineral microcapsules: 0.1 kg; Hydroxypropyl methylcellulose: appropriate amount (prepared into a 5% aqueous solution) Preparation steps: S310, Basic mixing: Mix 10 kg of konjac refined flour and 10 kg of resistant dextrin in a mass ratio of 1:1, and use a three-dimensional mixer to mix for 15 minutes until uniform.

[0068] S320, Twin-screw extrusion: A. Set the segmented temperature control mode: Feeding section: 85 °C, Kneading section: 105 °C, Discharging section: 115 °C; B. Screw speed control: Feeding section: 120 rpm, Kneading section: 150 rpm, and continuously extrude to form a composite.

[0069] S330, Gradient cooling and pulverization: The spiral conveyor cooler cools in three stages: The first stage: 80 °C → 50 °C (10 °C / min, 3 min), the second stage: 50 °C → 25 °C (5 °C / min, 5 min), the third stage: 25 °C → 5 °C (2 °C / min, 10 min); Introduce dehumidified air with a dew point of -25 °C (flow rate 2.5 m³ / min), vortex ultra-fine pulverization: Nitrogen protection environment, pulverization pressure 0.7 MPa, rotor speed 9000 rpm, feeding speed 10 kg / h, polytetrafluoroethylene-coated rotor, ultrasonic screening (100 / 80 mesh), and pulse air drying until the moisture content ≤ 5%.

[0070] S340, Premix preparation: Take 10 kg of pulverized composite and mix it with 1 kg of inulin and 0.5 kg of soy protein, and stir for 15 minutes according to a mass ratio of 100:10:5.

[0071] S350, Nutritional fortification: Mix the premix with 0.1 kg of vitamin and mineral microcapsules, and stir for 10 minutes according to a mass ratio of 100:1.

[0072] S360, Fluidized bed granulation: Add the fortified premix to a fluidized bed granulator, spray in a 5% hydroxypropyl methylcellulose solution (15 mL / min), and control the inlet air temperature at 55 °C for granulation.

[0073] S370, Drying and packaging: Dry the granular product at 45 °C until the moisture content ≤ 5% Process characteristics: segmented extrusion with temperature control to ensure molecular crosslinking; gradient cooling to maintain material properties; nitrogen protection for grinding to prevent oxidation; dehumidified air to control water activity ≤ 0.3; wear-resistant coating to reduce equipment adhesion.

[0074] Data analysis of Example 3: 1. Verification of extrusion process parameters: Actual temperature of the kneading section of the extruder: 106.2 ± 0.8 °C, technical standard 100 - 110 °C; proportion of screw speed increase: 27.5%, technical standard 20 - 30%; change in molecular weight distribution of the composite: peak shifted 15% to the right, using gel permeation chromatography.

[0075] 2. Cooling and grinding effects: Final temperature of gradient cooling: 4.8 ± 0.3 °C, using infrared temperature measurement; passing rate of particle size after grinding: 95.3%, using sieving method (80 - 100 mesh); oxygen content in nitrogen environment: 0.4%, using gas analyzer; highest temperature in grinding chamber: 33.7 °C, using thermocouple monitoring.

[0076] 3. Product performance test, as shown in Table 2: Table 2 Item Example 3 Uncontrolled temperature control group Retention rate of konjac glucomannan 97.2% 83.5% Redispersion precipitation rate (10min) 8% 22% Water activity Aw 0.28 0.41 It can be obtained that the gradient cooling process increases the retention rate of the intrinsic viscosity of konjac polysaccharide by 16.3% (p < 0.05).

[0077] Example 4: Raw material preparation: konjac flour: 10 kg; resistant dextrin: 10 kg; inulin: 1 kg; soy protein isolate: 0.5 kg; vitamin and mineral microcapsules: 0.1 kg; hydroxypropyl methylcellulose: appropriate amount (prepared into 5% aqueous solution); silicon dioxide (flow aid): 3 g (0.3% of the inulin mass); lecithin ethanol solution: 4 mL (10% concentration, 0.8% of the soy protein mass).

[0078] Preparation steps: S410. Basic mixing: Mix 10 kg of konjac flour and 10 kg of resistant dextrin in a mass ratio of 1:1, and use a V-type mixer to mix for 15 minutes until uniform.

[0079] S420. Twin-screw extrusion: Add the mixed powder to a twin-screw extruder, set the extrusion temperature at 100 °C to form a konjac-resistant dextrin composite.

[0080] S430. Cooling and grinding: Cool the extrusion product to room temperature and grind it to 80 - 100 mesh.

[0081] S440. Premix Preparation: A. Precise weighing: Ground complex: 10 kg; inulin: 1 kg; soy protein isolate: 0.5 kg. B. Primary premixing: Take 5 kg of the complex and mix it with 1 kg of inulin, add 3 g of silica, premix for 4 minutes, and let it stand for 5 minutes to eliminate static electricity. C. Stepwise mixing: Add the remaining 5 kg of the complex in two portions with a 2-minute interval, and mix for 5 minutes each time. D. Protein addition: Atomize and spray 0.5 kg of soy protein at a rate of 0.8 g / s, and simultaneously spray 4 mL of a lecithin ethanol solution (10% concentration, 0.25 mL / s), and stir at a low speed (9 r / min) for a total mixing time of 18 minutes.

[0082] S450. Nutritional fortification: Mix the premix with 0.1 kg of vitamin and mineral microcapsules, and stir for 10 minutes at a mass ratio of 100:1.

[0083] S460. Fluidized bed granulation: Add the fortified premix to a fluidized bed granulator, spray a 5% hydroxypropyl methylcellulose solution (15 mL / min), and control the inlet air temperature at 55 °C for granulation.

[0084] S470. Drying and packaging: Dry the granular product at 45 °C until the moisture content ≤ 5%.

[0085] Process characteristics: 1. Stepwise mixing ensures uniformity: Inulin is premixed with part of the complex, and the remaining complex is added in two portions. 2. Anti-caking treatment: Silica eliminates static electricity, and lecithin improves the protein dispersibility. 3. Atomized powder spraying technology: Precisely control the powder spraying rate (0.5 - 1.0 g / s), and synchronously spray the liquid to ensure the coating effect.

[0086] Data analysis of Example 4: 1. Key data of the mixing process: Silica addition amount: 0.28%, control range 0.1 - 0.3%; Spray uniformity of the lecithin solution: CV = 4.2%, analyzed by high-speed photography; Mixing uniformity (CV value): 3.8%, analyzed by near-infrared spectral imaging.

[0087] 2. Protein dispersion effect, as shown in Table 3: Table 3 Test item Example 4 Direct mixing group Soy protein dispersion index 0.88 0.52 Dissolution time (completely dispersed) 28 seconds 51 seconds Particle size distribution span 1.15 1.87 3. Static electricity control effect, as shown in Table 4: Table 4 Index Before treatment After treatment Static voltage on the powder surface 5.6 kV 0.3 kV Equipment adhesion loss rate 0.8% 5.2% Difference between mixing batches ±1.2% ±6.5% It can be obtained that: Lecithin coating increases the solubility of soy protein near its isoelectric point by 42%; The stepwise mixing process reduces energy consumption by 35% and increases production capacity by 28% (compared with traditional mixing); Static electricity control reduces the raw material loss rate by 84%.

[0088] Example 5: Raw material preparation: Konjac flour: 10 kg; Resistant dextrin: 10 kg; Inulin: 1 kg; Soy protein isolate: 0.5 kg; Vitamin and mineral microcapsules: 0.1 kg; Hydroxypropyl methylcellulose: appropriate amount (prepared into a 5% aqueous solution); Nano-silica aerosol: 0.075 g (0.075% of the mass of the microcapsules); Sodium alginate solution: 1% concentration, 30 mL (0.03% of the total mass of the premix).

[0089] Preparation steps: Step S510, Basic mixing: Mix 10 kg of konjac flour and 10 kg of resistant dextrin in a mass ratio of 1:1; Use a three-dimensional mixer to mix for 15 minutes until uniform.

[0090] Step S520, Twin-screw extrusion: Add the mixed powder to a twin-screw extruder, set the extrusion temperature at 100 °C to form a konjac-resistant dextrin complex.

[0091] Step S530, Cooling and grinding: Cool the extruded product to room temperature and grind it to 80 - 100 mesh.

[0092] Step S540, Premix preparation: Take 10 kg of the ground complex and mix it with 1 kg of inulin and 0.5 kg of soy protein, stir for 15 minutes in a mass ratio of 100:10:5.

[0093] Step S550, Nutritional fortification: A. Precise weighing: Premix: 10 kg; Vitamin and mineral microcapsules: 0.1 kg B. Microcapsule pre-dispersion: Place the microcapsules in a fluidized bed mixer, introduce dry air with RH ≤ 30% (1.2 m³ / min), add 0.075 g of nano-silica aerosol, and pre-disperse for 7 minutes; C. Step-by-step mixing: Add the premix in three batches (with an interval of 3 minutes); The mixing speed is 18 r / min; Each time of addition is synchronously sprayed with 10 mL of sodium alginate solution (from claim 10). D. Electrostatic control: Pause for 1 minute every 3 minutes of mixing, and the total mixing time is 14 minutes.

[0094] S560, Fluidized bed granulation: Add the fortified premix to a fluidized bed granulator, spray in a 5% hydroxypropyl methylcellulose solution (15 mL / min), and control the inlet air temperature at 55 °C for granulation.

[0095] S570, Drying and packaging: Dry the granular product at 45 °C until the moisture content ≤ 5%.

[0096] Process characteristics: 1. Fluidized bed pre-dispersion technology: Control the humidity ≤ 30% to prevent moisture absorption, and nano-silica enhances fluidity.

[0097] 2. Progressive mixing: The premix is added in three times, and the mixing speed is precisely controlled (15 - 20 r / min); 3. Antistatic treatment: Intermittent mixing eliminates charge accumulation. 4. Surface modification: Sodium alginate solution improves the particle wettability, and synchronous liquid spraying ensures uniform coating.

[0098] Data analysis of Example 5:; 1. Microcapsule dispersion performance test, as shown in Table 5: Table 5 Test item Example 5 Conventional mixing process Pre - dispersion uniformity (CV value) 4.1% 12.6% Adsorption efficiency of nano - silica 92.3% - Micro - capsule breakage rate after mixing 1.8% 7.5% 1. Fluidized bed mixing effect: Air relative humidity control: 28.5 ± 1.2% RH, using a humidity sensor; sodium alginate coating coverage rate: 89.7%, using the fluorescence labeling method; component segregation index after mixing: 0.05, using near-infrared imaging.

[0099] 2. Nutrient retention comparison, as shown in Table 6: Table 6 Component Retention rate of Example 5 Retention rate of traditional process Vitamin B12 (3 months) 94.2% 76.8% Ferrous ion oxidation rate 9.5% 34.2% Folic acid bioavailability 82.1% 63.4% Example 6: Raw material preparation: Konjac flour: 10 kg (moisture ≤ 8%, glucomannan ≥ 85%); resistant dextrin: 10 kg (DE value ≤ 10%); inulin: 1 kg (DP ≥ 10); soy protein isolate: 0.5 kg (protein ≥ 90%); vitamin and mineral microcapsules: 0.1 kg: compound vitamins: 15% (containing A, D, E, B groups, etc.), minerals: 20% (calcium carbonate, ferrous sulfate, etc.), wall material: 64.2% (arabic gum:β-cyclodextrin = 1:1), phospholipids: 0.8%, hydroxypropyl methylcellulose: 500 g (prepared into a 5% aqueous solution), silicon dioxide: 3 g (0.3% of inulin); lecithin ethanol solution: 4 mL (10% concentration, 0.8% of soy protein), nano-silicon dioxide aerosol: 0.075 g (0.075% of microcapsules), sodium alginate solution: 30 mL (1% concentration, 0.03% of premix).

[0100] Preparation steps: S610: Basic mixing: Put 10 kg of konjac flour and 10 kg of resistant dextrin into a three-dimensional mixer and mix for 15 minutes until uniform according to a mass ratio of 1:1.

[0101] S620: Twin-screw extrusion: A. Set segmented temperature control: feeding section: 85°C; kneading section: 105°C, screw speed 150 rpm (increased by 25%); discharging section: 115°C. B. Continuously extrude to form a composite.

[0102] S630: Gradient cooling and comminution: A. Three-stage spiral cooling: 80°C → 50°C (10°C / min, 3 min), 50°C → 25°C (5°C / min, 5 min), 25°C → 5°C (2°C / min, 10 min); B. Introduce dehumidified air with a dew point of -25°C (2.5 m³ / min); C. Eddy current comminution under nitrogen protection: PTFE-coated rotor, pressure 0.7 MPa, rotation speed 9000 rpm; D. Ultrasonic screening (100 / 80 mesh); E. Pulse air drying to moisture ≤ 5%.

[0103] S640: Premix preparation: A. Step-by-step mixing: Primary premixing: 5 kg of complex + 1 kg of inulin + 3 g of silica, premix for 4 minutes; Let stand for 5 minutes to eliminate static electricity; Add the remaining 5 kg of complex in two portions (with an interval of 2 minutes, mix for 5 minutes each time); B. Atomized powder spraying: Soy protein is sprayed in at a rate of 0.8 g / s; Synchronously spray 4 mL of lecithin ethanol solution (0.25 mL / s) C. Low-speed stirring (9 r / min), total mixing for 18 minutes S650: Nutritional fortification: A. Fluidized bed predispersion: Microcapsules + nano-silica aerosol, predisperse for 7 minutes with dry air with RH ≤ 30%; B. Add the premix in three portions (such as 30% + 30% + 40%): Each portion is separated by 3 minutes, synchronously spray 10 mL of sodium alginate solution, mixing speed 18 r / min, C. Let stand for 1 minute to eliminate static electricity every 3 minutes of mixing, D. Total mixing time is 14 minutes.

[0104] S660: Fluidized bed granulation: Spray in 5% hydroxypropyl methylcellulose (15 mL / min), granulate at an inlet air temperature of 55°C (particles 0.4 - 0.6 mm).

[0105] S670: Drying and packaging: Hot air drying at 45°C to moisture ≤ 5%, nitrogen filling for packaging.

[0106] Integrated process advantages: 1. Double protection of microcapsules; 2. Precise temperature control extrusion; 3. Inert environment treatment; 4. Intelligent mixing system; 5. Nutritional synergistic effect.

[0107] Data analysis of Example 6: 1. Comprehensive process verification data: Reduction of the GI value of the extruded complex: 46.3 (control 58.7), in vitro digestion method; Sustained release effect of microcapsules (2 h): Release rate 62%, dialysis membrane method; Total mixing energy consumption: Reduced by 41%, electrical energy monitoring.

[0108] 2. Product quality analysis Sphericity of particles: 93.5%, industry standard ≥ 80%; Dispersion stability (2 h): No stratification; Total retention rate of vitamins: 91.4%, industry standard ≥ 75%.

[0109] 3. Accelerated stability test (40 °C / 75% RH), as shown in Table 7: Table 7 Time Water activity AW Proportion of caking area Retention of vitamin C 0 month 0.29 0% 100% 3 months 0.32 1.2% 88.5% 6 months 0.35 3.7% 76.2% As can be seen from the above: The integration process increases the retention rate of nutrients during storage at room temperature by 25 - 40%; Nitrogen protection during grinding enables the inhibition rate of polyphenol oxidation to reach 92.4%; The composite wall material microcapsules exhibit a stepwise release characteristic in simulated gastrointestinal fluids.

[0110] The equipment quantities and processing scales described here are used to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be apparent to those skilled in the art.

[0111] Although the embodiments of the present invention have been disclosed as above, it is not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to specific details and the examples shown and described here.

Claims

1. A method for preparing a low GI konjac meal replacement powder, characterized in that: The following steps are involved: S1, konjac flour and resistance dextrin are mixed according to a mass ratio of 1:0.5-1:2 to obtain a mixed powder; S2, the mixed powder is placed in a twin-screw extruder, and extrusion treatment is carried out under the condition of 80 ℃-120 ℃ at an extrusion temperature, so that konjac flour and resistance dextrin form a complex, the complex is cooled, and crushed to a particle diameter of 80 mesh-100 mesh; S3, mixing the crushed composite with inulin and soy protein isolate in a mass ratio of 100:10:5 to obtain a premix; S4, mixing the premix with the vitamin and mineral microcapsules in a mass ratio of 100:1 to obtain a fortified premix; S5. Place the fortified premix in a fluidized bed granulator, use a 5% by mass hydroxypropyl methylcellulose aqueous solution as a binder, spray at a rate of 10 mL / min-20 mL / min, and an inlet air temperature of 50° C.-60° C. to perform fluidized bed granulation to obtain a granular meal replacement powder; S6. Dry the granular meal replacement powder at 40° C.-50° C. until the moisture content is less than 5%, thereby obtaining a low GI konjac meal replacement powder.

2. The method for preparing the low GI konjac meal replacement powder according to claim 1, wherein The vitamin and mineral microcapsules contain: 10%-20% by mass of complex vitamins, 15%-25% of minerals and 55%-75% of wall materials; wherein the complex vitamins include: vitamins A, D, E, B1, B2, B6, B12, folic acid and calcium pantothenate; the minerals include calcium carbonate, ferrous sulfate, zinc gluconate and sodium selenite; the wall material is composed of gum arabic and β-cyclodextrin in a mass ratio of 1:1-1:2; The preparation method of the vitamin and mineral microcapsules comprises: The compound vitamins and minerals are dispersed in a wall material solution at 40-50°C, homogenized and then spray-dried, with an inlet air temperature of 150-160°C and an outlet air temperature of 70-80°C, to obtain vitamin and mineral microcapsules with a particle size of 50μm-100μm.

3. The method for preparing the low GI konjac meal replacement powder as claimed in claim 2, characterized in that, In the vitamin and mineral microcapsules, 0.5% to 1% of phospholipids are added as emulsifiers.

4. The method for preparing the low GI konjac meal replacement powder according to claim 1, wherein In S2, the twin-screw extruder adopts a segmented temperature control mode, wherein the temperature of the feed section is 80°C-90°C, the temperature of the mixing section is 100°C-110°C, the temperature of the discharge section is 110°C-120°C, and the screw speed in the mixing section is 20%-30% higher than that in the feed section.

5. The method for preparing the low GI konjac meal replacement powder as claimed in claim 4, characterized in that, The composite is cooled and crushed to a particle size of 80 meshes to 100 meshes, specifically: S201, the extruded composite is subjected to gradient cooling through a screw conveyor cooler: the first stage: 80°C → 50°C, cooling rate 10°C / min, time 3min; the second stage: 50°C → 25°C, cooling rate 5°C / min, time 5min; the third stage: 25°C → 5°C, cooling rate 2°C / min, time 10min; S202, putting the cooled composite into a vortex ultrafine pulverizer, and pulverizing it under nitrogen protection, with the control parameters being: pulverizing pressure 0.6-0.8MPa, rotor speed 8000-10000rpm, feed rate 8-12kg / h, pulverizing chamber temperature ≤35°C; S203, using an ultrasonic vibration screening system to classify the crushed product: the first-level screen is 100 mesh, the second-level screen is 80 mesh, the vibration frequency is 28-32kHz, and the amplitude is 0.5-1mm; S204, collect the material between 80-100 mesh sieves, and dry them by pulse airflow to make the moisture content ≤5%.

6. The method for preparing the low GI konjac meal replacement powder according to claim 5, wherein: During the gradient cooling process of S201, dehumidified air with a dew point of ≤-15°C is introduced into the spiral conveyor cooler at a flow rate of 2-3 m³ / min, so that the water activity Aw of the composite at the cooling end point is ≤0.35; In S202, the rotor surface of the vortex superfine pulverizer is coated with a polytetrafluoroethylene wear-resistant coating with a thickness of 50-80 μm to reduce the adhesion of konjac powder.

7. The method for preparing the low GI konjac meal replacement powder according to claim 1, wherein The S3 specifically includes: S301. Accurately weigh each component according to the mass ratio of complex: inulin: soy protein isolate = 100:10:5; S302, premixing inulin and part of the complex at a mass ratio of 1:1 for 3-5 minutes to form a primary mixture; S303, adding the remaining compound twice, each time with an interval of 2 minutes, and mixing for 5 minutes; S304. Finally, add the soy protein isolate in the form of atomized powder spraying at a rate of 0.5-1.0 g / s. Meanwhile, keep the mixing container stirring at a low speed of 8-10 r / min. The total mixing time is 15-20 minutes.

8. The method for preparing the low GI konjac meal replacement powder according to claim 7, wherein: In S302, when the inulin and part of the composite are premixed, 0.1-0.3% of silicon dioxide by weight of the inulin is added as a flow aid, and the premix is ​​allowed to stand for 5 minutes to eliminate static electricity; In the above S304, a lecithin ethanol solution accounting for 0.5-1.0% of the mass of the soybean protein isolate is sprayed simultaneously during the atomization powder spraying, with a concentration of 10% and a spraying rate of 0.2-0.3 mL / s.

9. The method for preparing the low GI konjac meal replacement powder according to claim 1, wherein The S4 specifically includes: S401. Accurately weigh each component according to the mass ratio of premix: vitamin and mineral microcapsule = 100:1; S402, placing the vitamin and mineral microcapsules in a fluidized bed mixer, introducing dry air with a relative humidity of ≤30% at a flow rate of 1-1.5 m³ / min, and pre-dispersing the vitamin and mineral microcapsules for 5-8 minutes; S403, adding the premix into the fluidized bed three times, with an interval of 3 minutes between each addition, and controlling the mixing speed at 15-20 r / min, with a total mixing time of 12-15 minutes; S404. During the mixing process, the mixing is stopped every 3 minutes and allowed to stand for 1 minute to eliminate static electricity accumulation.

10. The method for preparing the low GI konjac meal replacement powder according to claim 9, characterized in that: In the S402, nano-silicon dioxide aerosol accounting for 0.03-0.08% of the mass of the vitamin and mineral microcapsules and having a particle size of 20-50 nm is added to the dry air to enhance the fluidity and anti-adhesion of the vitamin and mineral microcapsules; In the S403, each time the premix is ​​added, a sodium alginate solution accounting for 0.02-0.05% of the mass of the premix is ​​sprayed in simultaneously, with a concentration of 1% and a spraying rate of 0.1-0.2 mL / s.

Images