Bean product plant-based fruit freeze-dried block and preparation method thereof

Abstract

The invention discloses a bean product plant-based fruit freeze-dried block and a preparation method thereof, and belongs to the technical field of food processing. At present, most of freeze-dried fruit products in the market contain animal-derived components, increase the risk of cardiovascular diseases, are poor in taste and single in taste, and cannot meet people with special diet requirements. In order to solve the problems, the bean product plant-based fruit freeze-dried block is prepared from various raw materials such as fruit puree, soybean protein powder, pea protein powder and chickpea powder through specific processes such as raw material treatment, material blending, fermentation, dehydration, spreading, quick freezing, freeze-drying and packaging. The product does not contain animal components, and is rich and balanced in nutrition, high in content of protein, dietary fiber and the like, excellent in taste and flavor and good in reconstitution property. The food is mainly used for meeting the diet requirements of special crowds such as pure vegetarians, dairy product allergy and lactose intolerance, and can also be used as healthy snacks of common consumers.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, and particularly relates to a plant-based fruit freeze-dried block made from soy products and a preparation method thereof. Background Art

[0002] Although vacuum freeze-drying technology has been widely used in food processing to provide high-quality dehydrated foods, most of the freeze-dried fruit products on the market contain animal-derived ingredients such as dairy products, which can increase the risk of cardiovascular diseases and have an adverse impact on human health. In addition, existing freeze-dried fruit and vegetable products often have poor taste and a single flavor, lacking consideration for people with special dietary needs (such as vegetarians and lactose intolerant people). Therefore, it is of great significance to develop a freeze-dried fruit product without animal ingredients, rich in nutrition and with excellent taste. Summary of the Invention

[0003] The present invention provides a plant-based fruit freeze-dried block made from soy products and a preparation method thereof. Through innovative processes such as replacing animal-derived ingredients with a plant-based formula, ultrafine grinding and enzymatic hydrolysis technology, probiotic microencapsulation, and segmented freeze-drying process, a fruit freeze-dried block without animal ingredients, rich in nutrition and with excellent taste is prepared.

[0004] To achieve these and other advantages in accordance with the present invention, there is provided a plant-based fruit freeze-dried block made from soy products, comprising the following raw materials in parts by weight: 40 - 160 parts of fruit puree, 8 - 24 parts of soy protein powder, 7 - 21 parts of pea protein powder, 5 - 15 parts of chickpea powder, 20 - 60 parts of instant coconut powder, 10 - 30 parts of flavoring agent, 1 - 10 parts of cyclodextrin, 1 - 10 parts of trehalose, 0.01 - 0.1 part of vitamin E, 0.05 - 0.5 part of pectinase, 0.05 - 0.5 part of cellulase, 0.01 - 0.1 part of microencapsulated Lactobacillus acidophilus bacterial agent, 0.1 - 0.3 part of natural pigment, 0.1 - 0.5 part of soy lecithin, and 0.5 - 1 part of resistant dextrin.

[0005] Preferably, in the plant-based fruit freeze-dried block made from soy products, the fruit puree is one of strawberry puree, blueberry puree, pineapple puree, peach puree, kiwi puree, and passion fruit puree.

[0006] Preferably, in the plant-based fruit freeze-dried block made from soy products, the flavoring agent is one of apple concentrate, lemon juice, and acerola cherry powder.

[0007] Preferably, in the plant-based fruit freeze-dried block made from soy products, the natural pigment is one of beet red, β-carotene, and spirulina powder.

[0008] The present invention also provides a preparation method of a plant-based fruit freeze-dried block made from soy products, comprising the following steps: Step 1. Raw material pretreatment: Coarsely crush soy protein, pea protein, and chickpeas respectively, then vacuum dry them until the moisture content is lower than 10%. Next, use a jet mill to ultrafinely crush them under a high-speed air flow with a speed > 100 m / s until the powder particle size ≤ 25 μm, obtaining soy protein powder, pea protein powder, and chickpea powder; Meanwhile, immerse the pre-frozen fruit in a 4°C preservative coating solution for 15 minutes, take it out and let it dry, then put it into a 4°C low-temperature water bath and slowly thaw until the texture is soft. After removing the surface moisture, perform homogenization treatment, and then filter it through a 200 - 500 μm sieve to obtain fruit puree, which is refrigerated at 4°C for standby.

[0009] Step 2. Material blending: Weigh various raw materials by weight. First, mix soy protein powder, pea protein powder, and chickpea powder to obtain a mixed bean powder. Then, mix the mixed bean powder with soy lecithin, resistant dextrin, flavoring agent, and 50 - 100 parts by weight of water, and stir and mix. Next, add fruit puree, instant coconut powder, cyclodextrin, trehalose, vitamin E, pectinase, cellulase, Lactobacillus acidophilus microcapsule bacterium agent, natural pigment, and 50 - 100 parts by weight of water, stir and mix, and then use a high-pressure microfluidic homogenizer to perform homogenization treatment at a pressure of 120 MPa to obtain a mixed material; Step 3. Mild fermentation treatment: Keep the mixed material at 36°C for heat preservation and fermentation for 2 - 4 hours; Step 4. Dehydration: Heat the mixed material to 105°C to evaporate the water, and the solid content is 20% - 30%; Step 5. Material spreading: Evenly spread the mixed material in a tray mold, and the spreading thickness is not higher than 5 mm; Step 6. Quick freezing: Rapidly reduce the temperature of the mixed material to - 80°C within 5 minutes, and keep it at a constant temperature for pre-freezing for 12 hours to completely freeze the material, obtaining a pre-frozen semi-finished product; Step 7. Heating and freeze-drying: Perform segmented heating on the pre-frozen semi-finished product, and the temperature settings are: the first stage - 40°C, heating for 6 hours; the second stage - 25°C, heating for 6 hours; the third stage - 10°C, heating for 6 hours; the fourth stage 5°C, heating for 6 hours; the fifth stage 25°C, heating for 6 hours; the vacuum degree is maintained at 10 - 20 Pa; Step 8. Aseptic discharging and packaging: Discharge the material in a - 20°C aseptic environment and perform nitrogen filling and sealed packaging.

[0010] Preferably, in the method for preparing the freeze-dried block of fruit with soy product plant base, the preparation method of the preservative coating solution is: Dissolve 1 g of chitosan in 100 mL of a citric acid solution with a mass fraction of 1%, stir until completely dissolved to obtain a chitosan solution, add 0.5 g of tea polyphenols, and stir well to prepare the preservative coating solution.

[0011] Preferably, in the method for preparing the freeze-dried block of soy product-based plant fruit, the method for preparing the Lactobacillus acidophilus microcapsule agent is as follows: Mix Lactobacillus acidophilus with a 2% sodium alginate solution at a mass ratio of 1:10, and drip it into a 1.5% CaCl 2 - 0.5% chitosan solution through an electrostatic atomization device at a voltage of 15 kV to form microcapsules with a particle size of 100 - 200 μm. Immerse the microcapsules in a 5% sodium silicate solution for 30 minutes to deposit a nano-SiO layer with a thickness of 50 - 100 nm on the surface. 2 Then, modify the surface with a 0.1 mg / mL lysozyme solution to obtain the Lactobacillus acidophilus microcapsule agent, and store it refrigerated at 4°C for later use.

[0012] Preferably, in the method for preparing the freeze-dried block of soy product-based plant fruit, before using pectinase and cellulase in the second step, a double-layer embedding treatment is first performed. The inner layer is a liposome embedding layer composed of phosphatidylcholine and cholesterol at a mass ratio of 7:3, and the outer layer is a sodium alginate-chitosan composite microsphere; the composite microsphere degrades at pH ≤ 5.0.

[0013] Preferably, in the method for preparing the freeze-dried block of soy product-based plant fruit, the double-layer embedding treatment method of pectinase and cellulase includes the following steps: S1. Inner layer liposome embedding: Dissolve phosphatidylcholine and cholesterol at a mass ratio of 7:3 in absolute ethanol, form a lipid film by rotary evaporation at 50°C, add a phosphate buffer solution with a pH of 7.0 for hydration to obtain a liposome solution; dissolve pectinase or cellulase in the liposome solution, and emulsify and homogenize it at 50°C for 10 min under nitrogen protection to form an enzyme-liposome complex, and control the liposome particle size to be 30 - 50 μm. S2. Outer layer microsphere coating: Mix the enzyme-liposome complex obtained in S1 with a 2% sodium alginate solution at a volume ratio of 1:5, and drip it into a curing solution containing 1.5% CaCl 2 and 0.5% chitosan through an electrostatic spraying device at a voltage of 20 kV and a spraying distance of 10 cm to form a sodium alginate-chitosan composite microsphere; after curing for 30 min, collect by centrifugation and freeze-dry to obtain a double-layer embedded enzyme preparation. Among them, the particle size of the composite microsphere is 50 - 100 μm, and the mass ratio of sodium alginate to chitosan is 3:1.

[0014] Preferably, in the method for preparing the freeze-dried block of soy product-based plant fruit, the fermentation treatment in the third step adopts a dynamic regulation system, including: real-time monitoring of the pH value and lactic acid concentration of the mixture. When the growth rate of lactic acid concentration > 0.2% / min, automatically reduce the temperature from 36°C to 34°C and increase the stirring rate by 10 - 20%.

[0015] The present invention has at least the following beneficial effects: I. Rich and balanced nutrition: Mixing soy protein, pea protein and chickpea flour provides a complete amino acid combination and enhances nutritional value. After testing, the protein content of the product reaches 16.8% - 18.2%, and the essential amino acid score (EAAI) reaches 0.92, significantly higher than that of common single-plant protein freeze-dried foods on the market. At the same time, the dietary fiber content is increased to 8.4% - 9.1%, and it also contains various vitamins and minerals, making the nutrition more balanced.

[0016] II. Improving taste and flavor: Processing soy products through ultrafine grinding technology makes the powder particle size uniform. Combining with anti-caking agents (soy lecithin, resistant dextrin) improves solubility and uniformity, and improves texture and taste. Using pectinase and cellulase to enzymatically hydrolyze fruits enhances the combination of fruits and soy products, optimizing taste, color and functionality. Adding Lactobacillus acidophilus for fermentation reduces the raw bean flavor of beans, increases the acidity and mellow fragrance of the product, making the overall flavor more attractive. Texture analysis shows that the hardness of the product is maintained at 38.2 - 39.1N, which is consistent with the optimal taste range (35 - 40N), the taste is more crispy and softer after rehydration.

[0017] III. Optimizing product quality: Adopting rapid cryogenic pre-freezing and low-temperature vacuum drying technologies maximally retains the active ingredients and natural flavors in fruits and plant-based materials. The segmented heating freeze-drying process precisely controls the sublimation rate of moisture, avoiding tissue collapse, surface hardening and degradation of heat-sensitive components, ensuring the uniformity, rehydration and quality stability of the product. After testing, the retention rate of vitamin C reaches 78.6%, and the retention rate of total phenol content reaches 83.4%, showing a significant improvement compared with traditional freeze-drying methods.

[0018] IV. Meeting the needs of special groups: The product does not contain animal ingredients and is suitable for special groups such as vegetarians, those allergic to dairy products, and lactose intolerant people, filling the gap in the current freeze-drying industry for lack of precise, personalized and functional plant-based products.

[0019] V. Extending the shelf life and facilitating storage: The optimized process enables the product to have a shelf life of up to 18 months, extending by 50% compared with the 12-month shelf life of ordinary freeze-dried products, and is convenient for carrying and storage. The multi-layer co-extruded high-barrier film filled with nitrogen and sealed packaging, as well as the aseptic unloading and packaging environment, effectively prevent microbial contamination and ensure the safety of the product during storage and transportation.

[0020] VI. Environmental protection advantages: Plant-based foods generally have less impact on the environment than animal-based foods, helping to reduce greenhouse gas emissions and water resource consumption, and conforming to the concept of sustainable development.

[0021] Other advantages, objects, and features of the present invention will be partly reflected by the following description and partly understood by those skilled in the art through the research and practice of the present invention. Detailed Embodiment

[0022] The following further describes the present invention in detail with specific embodiments so that those skilled in the art can implement it according to the description in the specification.

[0023] 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.

[0024] It should be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial sources unless otherwise specified.

[0025] <Example 1> Preparation method of freeze-dried blocks of soy product-based plant fruits: Step 1. Raw material preparation and pretreatment: Coarsely crush soy protein, pea protein, and chickpeas respectively, then vacuum dry to a moisture content of 5%, and then ultrafinely crush with a jet mill under a high-speed air flow at a speed of 102 m / s to a powder particle size of 10 μm to obtain soy protein powder, pea protein powder, and chickpea powder; Immerse the pre-frozen fruits in a 4°C preservative coating solution and soak for 15 minutes, take them out and air-dry, then put them into a 4°C low-temperature water bath and slowly thaw until the texture is soft. After removing the surface moisture, homogenize, and then filter through a 200-μm sieve to obtain fruit puree, which is refrigerated at 4°C for standby; among them, the preparation method of the preservative coating solution is: dissolve 1 g of chitosan in 100 mL of a 1% citric acid solution by mass fraction, stir until completely dissolved to obtain a chitosan solution, add 0.5 g of tea polyphenols, and stir well to obtain the preservative coating solution; Prepare Lactobacillus acidophilus microcapsule bacterium agent: Mix Lactobacillus acidophilus with a 2% sodium alginate solution at a mass ratio of 1:10, and drip it into a 1.5% CaCl 2 -0.5% chitosan solution through an electrostatic atomization device at a voltage of 15 kV to form microcapsules with a particle size of 100 μm. Immerse the microcapsules in a 5% sodium silicate solution for 30 minutes to deposit a 50-nm-thick nano-SiO 2 layer on the surface, and then modify the surface with a 0.1 mg / mL lysozyme solution to obtain the Lactobacillus acidophilus microcapsule bacterium agent, which is refrigerated at 4°C for standby; Perform double-layer embedding treatment on pectinase and cellulase. The specific method is: S1. Inner embedding of liposome: Dissolve phosphatidylcholine and cholesterol in anhydrous ethanol at a mass ratio of 7:3, and form a lipid film by rotary evaporation at 50°C. Add phosphate buffer solution with a pH of 7.0 for hydration to obtain a liposome solution. Dissolve pectinase or cellulase in the liposome solution, and emulsify and homogenize at 50°C for 10 min under nitrogen protection to form an enzyme-liposome complex, controlling the liposome particle size to be 30 μm. S2. Outer microsphere coating: Mix the enzyme-liposome complex obtained in S1 with a 2% sodium alginate solution at a volume ratio of 1:5, and drop it into a curing solution containing 1.5% CaCl 2 and 0.5% chitosan through an electrostatic spraying device at a voltage of 20 kV and a spraying distance of 10 cm to form a sodium alginate-chitosan composite microsphere. After curing for 30 min, collect by centrifugation and freeze-dry to obtain a double-embedded enzyme preparation. Among them, the particle size of the composite microsphere is 50 μm, and the mass ratio of sodium alginate to chitosan is 3:1. Step Two. Material preparation: Weigh various raw materials according to the following parts by weight: 40 parts of pineapple puree, 8 parts of soy protein powder, 7 parts of pea protein powder, 5 parts of chickpea powder, 20 parts of instant coconut powder, 10 parts of acerola cherry powder, 1 part of cyclodextrin, 1 part of trehalose, 0.01 part of vitamin E, 0.05 part of pectinase, 0.05 part of cellulase, 0.01 part of Lactobacillus acidophilus microcapsule bacterium agent, 0.1 part of β-carotene, 0.1 part of soy lecithin, 0.5 part of resistant dextrin. First, mix soy protein powder, pea protein powder, and chickpea powder to obtain a mixed bean powder. Then, mix the mixed bean powder with soy lecithin, resistant dextrin, flavoring agent, and 50 parts by weight of water, stir and mix. Then, add pineapple puree, instant coconut powder, cyclodextrin, trehalose, vitamin E, pectinase, cellulase, Lactobacillus acidophilus microcapsule bacterium agent, natural pigment, and 50 parts by weight of water, stir and mix. Then, homogenize with a high-pressure microfluidic homogenizer at a pressure of 120 MPa to obtain a mixture. Step Three. Mild fermentation treatment: Keep the mixture at 36°C for 2 hours for fermentation. The fermentation treatment adopts a dynamic regulation system, including: real-time monitoring of the pH value and lactic acid concentration of the mixture. When the growth rate of lactic acid concentration > 0.3% / min, automatically reduce the temperature from 36°C to 34°C and increase the stirring rate by 10%. Step Four. Dehydration: Heat the mixture to 105°C to evaporate water, and the solid content is 20%. Step Five. Material spreading: Spread the mixture evenly in a tray mold with a spreading thickness of 5 mm. Step Six. Quick freezing: Quickly reduce the temperature of the mixture to -80°C within 5 min and pre-freeze at a constant temperature for 12 hours to completely freeze the material to obtain a pre-frozen semi-finished product. Step 7. Heat freeze-drying: The pre-frozen semi-finished product is heated in segments, and the temperature is set as follows: the first segment is -40°C for 6 hours; the second segment is -25°C for 6 hours; the third segment is -10°C for 6 hours; the fourth segment is 5°C for 6 hours; the fifth segment is 25°C for 6 hours; the vacuum degree is maintained at 10 - 20 Pa; Step 8. Aseptic discharging and packaging: Discharge in an aseptic environment at -20°C and perform nitrogen-filled sealed packaging.

[0026] <Example 2> Preparation method of freeze-dried blocks of soy product plant-based fruits: Step 1. Raw material preparation and pretreatment: Coarsely crush soy protein, pea protein, and chickpeas respectively, and then vacuum dry to a moisture content of 7%. Then, use a jet mill to ultra-finely crush them to a powder particle size of 15 μm under a high-speed air flow with a speed of 120 m / s to obtain soy protein powder, pea protein powder, and chickpea powder; Immerse the pre-frozen fruits in a 4°C preservative coating solution and soak for 15 minutes. Take them out and let them dry. Then, put them into a 4°C low-temperature water bath and slowly thaw until the texture is soft. After removing the surface moisture, perform homogenization treatment, and then filter through a 350-μm sieve to obtain fruit puree, which is refrigerated at 4°C for standby; among them, the preparation method of the preservative coating solution is: dissolve 1 g of chitosan in 100 mL of a citric acid solution with a mass fraction of 1%, stir until completely dissolved to obtain a chitosan solution, add 0.5 g of tea polyphenols, and stir well to prepare the preservative coating solution; Prepare Lactobacillus acidophilus microcapsule bacterium agent: Mix Lactobacillus acidophilus with a 2% sodium alginate solution at a mass ratio of 1:10, and drip it into a 1.5% CaCl 2 -0.5% chitosan solution through an electrostatic atomization device at a voltage of 15 kV to form microcapsules with a particle size of 150 μm. Immerse the microcapsules in a 5% sodium silicate solution for 30 minutes to deposit a 75-nm-thick nano-SiO 2 layer on the surface, and then modify the surface with a 0.1 mg / mL lysozyme solution to obtain the Lactobacillus acidophilus microcapsule bacterium agent, which is refrigerated at 4°C for standby; Perform double-layer embedding treatment on pectinase and cellulase. The specific method is as follows: S1. Inner layer embedding of liposome: Dissolve phosphatidylcholine and cholesterol in anhydrous ethanol at a mass ratio of 7:3, and form a lipid film by rotary evaporation at 50°C. Add a phosphate buffer solution with a pH of 7.0 for hydration to obtain a liposome solution; dissolve pectinase or cellulase in the liposome solution, and perform emulsification and homogenization at 50°C for 10 minutes under nitrogen protection to form an enzyme-liposome complex, and control the liposome particle size to be 40 μm; S2. Outer microsphere coating: Mix the enzyme-liposome complex obtained in S1 with a 2% sodium alginate solution at a volume ratio of 1:5. Drop it into a curing solution containing 1.5% CaCl 2 and 0.5% chitosan through an electrostatic spraying device at a voltage of 20 kV and a spraying distance of 10 cm to form sodium alginate-chitosan composite microspheres; After curing for 30 min, collect by centrifugation and freeze-dry to obtain a double-embedded enzyme preparation; Among them, the particle size of the composite microspheres is 75 μm, and the mass ratio of sodium alginate to chitosan is 3:1; Step 2. Material preparation: Weigh various raw materials according to the following parts by weight: 100 parts of kiwifruit puree, 16 parts of soy protein powder, 14 parts of pea protein powder, 10 parts of chickpea powder, 40 parts of instant coconut powder, 20 parts of lemon juice, 6 parts of cyclodextrin, 6 parts of trehalose, 0.05 part of vitamin E, 0.3 part of pectinase, 0.3 part of cellulase, 0.06 part of microcapsule bacterium agent of Lactobacillus acidophilus, 0.2 part of natural pigment spirulina powder, 0.3 part of soy lecithin, 0.7 part of resistant dextrin; First, mix soy protein powder, pea protein powder, and chickpea powder to obtain a mixed bean powder. Then, mix the mixed bean powder with soy lecithin, resistant dextrin, flavoring agent, and 75 parts by weight of water, and stir and mix. Then, add kiwifruit puree, instant coconut powder, cyclodextrin, trehalose, vitamin E, pectinase, cellulase, microcapsule bacterium agent of Lactobacillus acidophilus, natural pigment, and 75 parts by weight of water, and stir and mix. Then, homogenize with a high-pressure microfluidic homogenizer at a pressure of 120 MPa to obtain a mixed material; Step 3. Mild fermentation treatment: Keep the mixed material at 36 °C for 2 - 4 hours for fermentation; The fermentation treatment adopts a dynamic regulation system, including: real-time monitoring of the pH value and lactic acid concentration of the mixed material. When the growth rate of lactic acid concentration > 0.2% / min, automatically reduce the temperature from 36 °C to 34 °C and increase the stirring rate by 15%; Step 4. Dehydration: Heat the mixed material to 105 °C to evaporate water, and the solid content is 25%; Step 5. Material spreading: Spread the mixed material evenly in a tray mold with a spreading thickness of 4 mm; Step 6. Quick freezing: Rapidly reduce the temperature of the mixed material to -80 °C within 5 min and pre-freeze at a constant temperature for 12 hours to completely freeze the material to obtain a pre-frozen semi-finished product; Step 7. Heating and freeze-drying: Perform segmented heating on the pre-frozen semi-finished product, and the temperature settings are: the first stage -40 °C, heating for 6 h; the second stage -25 °C, heating for 6 h; the third stage -10 °C, heating for 6 h; the fourth stage 5 °C, heating for 6 h; the fifth stage 25 °C, heating for 6 h; The vacuum degree is maintained at 10 - 20 Pa; Step 8, Aseptic Discharging and Packaging: Discharge under aseptic environment at -20°C, and conduct nitrogen filling and sealed packaging.

[0027] <Example 3> Preparation Method of Freeze-Dried Blocks of Plant-Based Fruit from Soybean Products Step 1, Raw Material Preparation and Pretreatment: Coarsely crush soy protein, pea protein, and chickpeas respectively, then vacuum dry to a moisture content of 9%, and further ultrafinely crush to a powder particle size of 25 μm under a high-speed air flow with a speed of 150 m / s using a jet mill to obtain soy protein powder, pea protein powder, and chickpea powder; Immerse the pre-frozen fruit in a 4°C preservative coating solution for 15 min, take it out and air dry, then put it into a 4°C low-temperature water bath and slowly thaw until the texture is soft. After removing the surface moisture, conduct homogenization treatment, and then filter through a 500-μm sieve to obtain fruit puree, which is refrigerated at 4°C for standby; among them, the preparation method of the preservative coating solution is: dissolve 1 g of chitosan in 100 mL of a citric acid solution with a mass fraction of 1%, stir until completely dissolved to obtain a chitosan solution, add 0.5 g of tea polyphenols, and stir well to prepare the preservative coating solution; Prepare Lactobacillus acidophilus microcapsule bacterium agent: Mix Lactobacillus acidophilus with a 2% sodium alginate solution at a mass ratio of 1:10, and drip it into a 1.5% CaCl 2 -0.5% chitosan solution through an electrostatic atomization device at a voltage of 15 kV to form microcapsules with a particle size of 200 μm. Immerse the microcapsules in a 5% sodium silicate solution for 30 minutes to deposit a 100-nm-thick nano-SiO 2 layer on its surface, and then modify the surface with a 0.1 mg / mL lysozyme solution to obtain the Lactobacillus acidophilus microcapsule bacterium agent, which is refrigerated at 4°C for standby; Conduct double-layer embedding treatment on pectinase and cellulase. The specific method is as follows: S1, Inner Liposome Embedding: Dissolve phosphatidylcholine and cholesterol at a mass ratio of 7:3 in absolute ethanol, form a lipid film by rotary evaporation at 50°C, add a phosphate buffer solution with a pH of 7.0 for hydration to obtain a liposome solution; dissolve pectinase or cellulase in the liposome solution, and conduct emulsification homogenization at 50°C for 10 min under nitrogen protection to form an enzyme-liposome complex, and control the liposome particle size to be 50 μm; S2, Outer Microsphere Coating: Mix the enzyme-liposome complex obtained in S1 with a 2% sodium alginate solution at a volume ratio of 1:5, and drip it into a solution containing 1.5% CaCl through an electrostatic spraying device at a voltage of 20 kV and a spraying distance of 10 cm 2In the curing solution of 0.5% chitosan, sodium alginate-chitosan composite microspheres are formed; after curing for 30 minutes, they are collected by centrifugation and freeze-dried to obtain a double-layer embedded enzyme preparation; wherein, the particle size of the composite microspheres is 100 μm, and the mass ratio of sodium alginate to chitosan is 3:1; Step 2. Material preparation: Weigh various raw materials according to the following parts by weight: 160 parts of passion fruit puree, 24 parts of soy protein powder, 21 parts of pea protein powder, 15 parts of chickpea powder, 60 parts of instant coconut powder, 30 parts of apple concentrated juice, 10 parts of cyclodextrin, 10 parts of trehalose, 0.1 part of vitamin E, 0.5 part of pectinase, 0.5 part of cellulase, 0.1 part of microcapsule preparation of Lactobacillus acidophilus, 0.3 part of beet red, 0.5 part of soy lecithin, and 1 part of resistant dextrin; First, mix soy protein powder, pea protein powder, and chickpea powder to obtain a mixed bean powder. Then, mix the mixed bean powder with soy lecithin, resistant dextrin, flavoring agent, and 100 parts by weight of water, stir and mix. Then, add passion fruit puree, instant coconut powder, cyclodextrin, trehalose, vitamin E, pectinase, cellulase, microcapsule preparation of Lactobacillus acidophilus, natural pigment, and 100 parts by weight of water, stir and mix. Then, homogenize with a high-pressure microfluidic homogenizer at a pressure of 120 MPa to obtain a mixed material; Step 3. Mild fermentation treatment: Keep the mixed material at 36 °C for 2 - 4 hours for fermentation; The fermentation treatment adopts a dynamic regulation system, including: real-time monitoring of the pH value and lactic acid concentration of the mixed material. When the growth rate of lactic acid concentration > 0.2% / min, automatically reduce the temperature from 36 °C to 34 °C and increase the stirring rate by 20%; Step 4. Dehydration: Heat the mixed material to 105 °C to evaporate water, and the solid content is 30%; Step 5. Material spreading: Spread the mixed material evenly in a tray mold, and the spreading thickness is 3 mm; Step 6. Quick freezing: Rapidly reduce the temperature of the mixed material to -80 °C within 5 minutes and keep it at a constant temperature for pre-freezing for 12 hours to completely freeze the material and obtain a pre-frozen semi-finished product; Step 7. Heating and freeze-drying: Perform segmented heating on the pre-frozen semi-finished product, and the temperature settings are: the first stage -40 °C, heating for 6 h; the second stage -25 °C, heating for 6 h; the third stage -10 °C, heating for 6 h; the fourth stage 5 °C, heating for 6 h; the fifth stage 25 °C, heating for 6 h; the vacuum degree is maintained at 10 - 20 Pa; Step 8. Aseptic discharging and packaging: Discharge in a sterile environment at -20 °C and perform nitrogen filling and sealing packaging.

[0028] <Example 4> Preparation method of freeze-dried block of plant-based fruit with soy products Step 1. Raw material preparation and pretreatment: Coarsely crush soy protein, pea protein, and chickpeas respectively, then vacuum dry them until the moisture content is 7%, and then ultrafinely crush them to a powder particle size of 15 μm under a high-speed air flow with a speed of 120 m / s using a jet mill to obtain soy protein powder, pea protein powder, and chickpea powder; Immerse the pre-frozen fruits in a 4°C preservative coating solution for 15 minutes, take them out and let them dry, then put them into a 4°C low-temperature water bath and slowly thaw until the texture is soft. After removing the surface moisture, perform homogenization treatment, and then filter through a 350 μm sieve to obtain fruit puree, which is refrigerated at 4°C for later use; among them, the preparation method of the preservative coating solution is: dissolve 1 g of chitosan in 100 mL of a citric acid solution with a mass fraction of 1%, stir until completely dissolved to obtain a chitosan solution, add 0.5 g of tea polyphenols, and stir well to prepare the preservative coating solution; Prepare Lactobacillus acidophilus microcapsule bacteria agent: Mix Lactobacillus acidophilus with a 2% sodium alginate solution at a mass ratio of 1:10, and drip it into a 1.5% CaCl 2 -0.5% chitosan solution through an electrostatic atomization device at a voltage of 15 kV to form microcapsules with a particle size of 150 μm. Immerse the microcapsules in a 5% sodium silicate solution for 30 minutes to deposit a 75 nm thick nano-SiO 2 layer on the surface, and then modify the surface with a 0.1 mg / mL lysozyme solution to obtain the Lactobacillus acidophilus microcapsule bacteria agent, which is refrigerated at 4°C for later use; Perform double-layer embedding treatment on pectinase and cellulase. The specific method is as follows: S1. Inner layer embedding of liposome: Dissolve phosphatidylcholine and cholesterol in absolute ethanol at a mass ratio of 7:3, and form a lipid film by rotary evaporation at 50°C. Add a phosphate buffer solution with a pH of 7.0 for hydration to obtain a liposome solution; dissolve pectinase or cellulase in the liposome solution, and perform emulsification homogenization at 50°C for 10 minutes under nitrogen protection to form an enzyme-liposome complex, and control the liposome particle size to be 40 μm; S2. Outer layer microsphere coating: Mix the enzyme-liposome complex obtained in S1 with a 2% sodium alginate solution at a volume ratio of 1:5, and drip it into a curing solution containing 1.5% CaCl 2 and 0.5% chitosan through an electrostatic spraying device at a voltage of 20 kV and a spraying distance of 10 cm to form sodium alginate-chitosan composite microspheres; after curing for 30 minutes, collect by centrifugation and freeze-dry to obtain a double-layer embedded enzyme preparation; among them, the particle size of the composite microspheres is 75 μm, and the mass ratio of sodium alginate to chitosan is 3:1; Step two. Material preparation: Weigh various raw materials according to the following parts by weight: 140 parts of strawberry puree, 24 parts of soy protein powder, 21 parts of pea protein powder, 15 parts of chickpea powder, 20 parts of instant coconut powder, 30 parts of apple concentrated juice, 10 parts of cyclodextrin, 6 parts of trehalose, 0.05 part of vitamin E, 0.05 part of pectinase, 0.05 part of cellulase, 0.01 part of Lactobacillus acidophilus microcapsule bacterium agent, 0.3 part of beet red, 0.3 part of soy lecithin, 0.8 part of resistant dextrin; First, mix soy protein powder, pea protein powder, and chickpea powder to obtain a mixed bean powder. Then, mix the mixed bean powder with soy lecithin, resistant dextrin, flavoring agent, and 75 parts by weight of water, and stir to mix. Next, add strawberry puree, instant coconut powder, cyclodextrin, trehalose, vitamin E, pectinase, cellulase, Lactobacillus acidophilus microcapsule bacterium agent, natural pigment, and 75 parts by weight of water, and stir to mix. Then, homogenize the mixture with a high-pressure microfluidic homogenizer at a pressure of 120 MPa to obtain a mixed material; Step 3: Mild fermentation treatment: Keep the mixed material at 36 °C for 2 - 4 hours for fermentation; The fermentation treatment uses a dynamic regulation system, including: real-time monitoring of the pH value and lactic acid concentration of the mixed material. When the growth rate of lactic acid concentration > 0.2% / min, automatically reduce the temperature from 36 °C to 34 °C and increase the stirring rate by 15%; Step 4: Dehydration: Heat the mixed material to 105 °C to evaporate the water, and the solid content is 25%; Step 5: Material spreading: Evenly spread the mixed material in a tray mold, and the spreading thickness is 5 mm; Step 6: Quick freezing: Rapidly reduce the temperature of the mixed material to -80 °C within 5 minutes, and keep it at a constant temperature for pre-freezing for 12 hours to completely freeze the material to obtain a pre-frozen semi-finished product; Step 7: Heating and freeze-drying: Perform segmented heating on the pre-frozen semi-finished product, and the temperature settings are: the first stage -40 °C, heating for 6 h; the second stage -25 °C, heating for 6 h; the third stage -10 °C, heating for 6 h; the fourth stage 5 °C, heating for 6 h; the fifth stage 25 °C, heating for 6 h; the vacuum degree is maintained at 10 - 20 Pa; Step 8: Aseptic discharging and packaging: Discharge the material in a sterile environment at -20 °C, and perform nitrogen filling and sealing packaging.

[0029] <Example 5> Same as Example 4, the difference is that: in the raw materials, strawberry puree is replaced with blueberry puree.

[0030] <Example 6> Same as Example 4, the difference is that: in the raw materials, strawberry puree is replaced with peach puree, and 10 parts of apple concentrated juice are replaced with 10 parts of acerola cherry powder.

[0031] <Comparative Example 1> Same as Example 4, the difference is that the pre-frozen fruits are not soaked in the preservative coating solution.

[0032] <Comparative Example 2> Same as Example 4, the difference is that the Lactobacillus acidophilus microcapsule agent is replaced with Lactobacillus acidophilus.

[0033] <Comparative Example 3> Same as Example 4, the difference is that pectinase and cellulase are not subjected to double-layer embedding treatment.

[0034] <Comparative Example 4> Same as Example 4, the difference is that the raw materials do not contain soy lecithin and resistant dextrin.

[0035] <Comparative Example 5> Same as Example 4, the difference is that in Step 2, the raw materials are directly mixed and then homogenized.

[0036] <Comparative Example 6> Same as Example 4, the difference is that the solid content in Step 4 is 35%.

[0037] <Comparative Example 7> Same as Example 4, the difference is that in Step 6, pre-freezing is carried out at -40°C for 12 hours.

[0038] <Comparative Example 8> Same as Example 4, the difference is that in Step 7, heat freeze-drying is carried out with a gradually continuous temperature rise.

[0039] <Comparative Example 9> Same as Example 4, the difference is that in Step 3, incubation is carried out at 36°C for 2 - 4 hours without regulation operation.

[0040] <Comparative Example 10> The specific steps for preparing fruit freeze-dried blocks by the traditional method include: ‌Step 1. Select and prepare fruits‌: Select high-quality strawberries, wash the strawberries, and cut them into uniform pieces with a size not exceeding 5 mm; ‌Step 2. Pretreatment‌: Soak the cut strawberry pieces in 0.5% light salt water for 15 min, take them out and dry the surface moisture, and spread them flat on the freezing tray; ‌Step 3. Freezing‌: Put the processed strawberry pieces into a cold storage at -40°C for pre-freezing for 24 hours; Step 4. ‌Vacuum freeze-drying‌: Put the pre-frozen strawberry pieces into a vacuum freeze-dryer, gradually and continuously raise the temperature to room temperature, and carry out drying treatment for 2 days, with a vacuum degree ≤ 50 Pa; Step 5. ‌Packaging and storage‌: After drying is completed, take out the freeze-dried fruit pieces and put them into a sealed bag for storage.

[0041] The freeze-dried blocks prepared in the above embodiments were subjected to sensory evaluation. The specific evaluation method was as follows: Ten experts with experience in tasting freeze-dried fruit blocks and ten ordinary consumers were invited as evaluators. They respectively tested and scored the freeze-dried fruit blocks prepared in each embodiment. The evaluation result was the average score of the 20 evaluators' scores. The scoring results were recorded in Table 2, and the sensory scoring criteria were as shown in Table 1.

[0042] The quality indexes of the freeze-dried blocks prepared in the above embodiments were measured or calculated, and the results were recorded in Table 2. The quality indexes included: hardness (the best taste was 35 - 40 N), elasticity, vitamin C retention rate, total phenol content retention rate, protein content, dietary fiber content, probiotic content, and shelf life. Among them, the shelf life was determined by placing the freeze-dried blocks in a normal-temperature, ventilated, and dry environment. The moisture content and peroxide value of the freeze-dried blocks were measured weekly. When the moisture content ≥ 5% or the peroxide value ≥ 10 meq / kg, the freeze-dried blocks were considered spoiled.

[0043] From the test results and scoring results in Table 2, it can be seen that the soy-based fruit freeze-dried blocks prepared by the method of the present invention (Examples 1 - 6) had a lower hardness compared to the fruit freeze-dried blocks prepared by the traditional method, and met the 35 - 40 N for the best taste. The elasticity increased by 12%, more nutrients were retained, and the overall sensory evaluation was close to full marks, meeting the tastes of most people; In Comparative Example 1, compared with Example 4, the hardness, elasticity, and sensory score decreased because the pre-frozen fruit was not soaked in the preservative coating solution. The chitosan + tea polyphenol coating could inhibit oxidative browning and microbial contamination. The lack of use resulted in the darkening of the color and loss of flavor of the fruit puree. The fruit tissue became loose due to oxidation and water seepage, and the texture deteriorated, thus leading to a decrease in the overall quality and a reduction in the sensory score; In Comparative Example 2, compared with Example 4, the vitamin C retention rate, total phenol content retention rate, protein content, dietary fiber content, and probiotic content all decreased because the Lactobacillus acidophilus microcapsule bacterium agent was replaced with Lactobacillus acidophilus, losing the protection of the mineralized layer of the microcapsule bacterium agent for Lactobacillus acidophilus, resulting in its damage during the freeze-drying process. At the same time, the lack of lysozyme allowed competing bacteria to consume nutrients, thus affecting the nutritional components and taste of the product and leading to a reduction in the sensory score; In Comparative Example 3, compared with Example 4, the sensory evaluation score decreased mainly because the pectinase and cellulase were not double-embedded, unable to accurately release and decompose the fruit cell wall, affecting the formation of the colloidal network and component fusion, and also resulting in the oxidative degradation of pigments, thus affecting the color and taste of the product; In Comparative Example 4, the hardness, elasticity, and sensory score all decreased compared to Example 4 because there was no soy lecithin and resistant dextrin in the raw materials, and the powder was prone to agglomeration, resulting in collapse during the freeze-drying process of the product, leading to a rough texture, sticky teeth in the mouthfeel, uneven fruit flavor distribution, and further affecting the taste and texture; In Comparative Example 5, the hardness, elasticity, and sensory score all decreased compared to Example 4 because in Step 2, the raw materials were directly mixed and then homogenized, and the problem of powder agglomeration could not be avoided, resulting in a decline in product quality; In Comparative Example 6, the hardness increased but the sensory score decreased compared to Example 4 because the solid content in Step 4 was 30%, higher than 25% in Example 4, making the texture of the freeze-dried product dense and too hard, affecting the taste and resulting in a decrease in the sensory score; In Comparative Example 7, the retention rates of vitamin C, total phenol content, protein content, and dietary fiber content all decreased compared to Example 4 because in Step 6, pre-freezing at -40°C for 12 hours was used, which, compared to the quick-freezing at -80°C in Example 4, could not make the water form tiny and uniform ice crystals quickly. The ice crystals were larger, and during the subsequent freeze-drying process, the water sublimated unevenly, affecting the texture and retention of nutritional components of the product and also resulting in a decrease in the sensory score; In Comparative Example 8, the retention rates of vitamin C, total phenol content, protein content, and dietary fiber content all decreased compared to Example 4, but the hardness increased because in Step 7, the heating freeze-drying was a gradually continuous temperature increase, resulting in cell wall collapse, harder texture, more surface cracks, and accelerating the oxidation reaction, seriously affecting the color, retention of nutritional components, and taste of the product, resulting in a decrease in the sensory score; In Comparative Example 9, the hardness and probiotic content both decreased compared to Example 4 because there was no regulation operation in Step 3, and it was impossible to inhibit the excessive aggregation of proteins caused by excessive acidification, affecting the stability of the three-dimensional structure of the colloid. The excessive acidity masked the fruity aroma and the taste was unbalanced, resulting in a decrease in the sensory score.

[0044] 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.

[0045] Although the embodiments of the present invention have been disclosed as above, they are 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 the equivalent scope, the present invention is not limited to specific details and the embodiments shown and described here.

Claims

1. A soy product plant-based fruit freeze-dried block, characterized in that: The invention comprises the following raw materials in parts by weight: 40-160 parts of fruit puree, 8-24 parts of soy protein powder, 7-21 parts of pea protein powder, 5-15 parts of chickpea powder, 20-60 parts of instant coconut powder, 10-30 parts of flavoring agent, 1-10 parts of cyclodextrin, 1-10 parts of trehalose, 0.01-0.1 parts of vitamin E, 0.05-0.5 parts of pectinase, 0.05-0.5 parts of cellulase, 0.01-0.1 parts of Lactobacillus acidophilus microcapsule agent, 0.1-0.3 parts of natural pigment, 0.1-0.5 parts of soy lecithin and 0.5-1 parts of resistant dextrin.

2. The soy product plant-based fruit freeze-dried block according to claim 1, characterized in that: The fruit puree is one of strawberry puree, blueberry puree, pineapple puree, peach puree, kiwi puree and passion fruit puree.

3. The soy product plant-based fruit freeze-dried block according to claim 1, characterized in that: The flavoring agent is one of apple juice concentrate, lemon juice and acerola powder.

4. The soy product plant-based fruit freeze-dried block according to claim 1, characterized in that: The natural pigment is one of beetroot red, beta-carotene and spirulina powder.

5. A method for preparing a soy product plant-based fruit freeze-dried block, characterized in that: The following steps are involved: Step 1, raw material pretreatment: coarsely grind the soy protein, pea protein and chickpea respectively, and then vacuum dry them to a moisture content of less than 10%, and then use a jet mill to ultrafinely grind them under a high-speed airflow of a speed of >100m / s to a powder particle size of ≤25μm to obtain soy protein powder, pea protein powder and chickpea powder; Meanwhile, the pre-frozen fruits are immersed in a 4°C preservative coating solution for 15 minutes, taken out and dried, and then placed in a 4°C low-temperature water bath, slowly thawed until the texture is soft, and the surface moisture is removed and then homogenized, and then filtered through a 200-500 μm sieve to obtain the fruit puree, which is refrigerated at 4°C for later use; Step 2, material preparation: various raw materials are weighed according to weight portions, first soy protein powder, pea protein powder, and chickpea powder are mixed to obtain mixed bean powder, the mixed bean powder is then mixed with soy lecithin, resistant dextrin, flavoring agent, and 50-100 parts by weight of water, stirred and mixed, and then fruit puree, instant coconut powder, cyclodextrin, trehalose, vitamin E, pectinase, cellulase, Lactobacillus acidophilus microcapsule agent, natural pigment, and 50-100 parts by weight of water are added, stirred and mixed, and then homogenized with a high-pressure microfluidizer at a pressure of 120 MPa to obtain a mixture; Step 3: Mild fermentation: ferment the mixture at 36°C for 2-4 hours; Step 4: Dehydration: Heat the mixture to 105°C to evaporate the water, and the solid content is 20%-30%; Step 5: Material spreading: Spread the mixture evenly in the tray mold with a spreading thickness not exceeding 5 mm; Step 6: Quick freezing: quickly reduce the temperature of the mixture to -80°C within 5 minutes, and pre-freeze at a constant temperature for 12 hours to completely freeze the material to obtain a pre-frozen semi-finished product; Step 7, heating freeze-drying: the pre-frozen semi-finished product is heated in sections, and the temperature is set as follows: the first section is -40°C, heating for 6 hours; the second section is -25°C, heating for 6 hours; the third section is -10°C, heating for 6 hours; the fourth section is 5°C, heating for 6 hours; the fifth section is 25°C, heating for 6 hours; the vacuum degree is maintained at 10-20 Pa; Step 8. Aseptic unloading and packaging: Unload in a sterile environment at -20℃ and seal with nitrogen.

6. The method for preparing the soy product plant-based fruit freeze-dried block according to claim 5, characterized in that: The preparation method of the preservative coating liquid is as follows: 1g of chitosan is dissolved in 100mL of 1% by mass citric acid solution, stirred until completely dissolved to obtain a chitosan solution, 0.5g of tea polyphenols is added, and stirred evenly to obtain a preservative coating liquid.

7. The method for preparing the soy product plant-based fruit freeze-dried block according to claim 5, characterized in that: The preparation method of the lactobacillus acidophilus microcapsule bacterial agent is as follows: lactobacillus acidophilus and 2% sodium alginate solution are mixed at a mass ratio of 1:10, and the mixture is dripped into a 1.5% CaCl2-0.5% chitosan solution at a voltage of 15 kV through an electrostatic atomization device to form microcapsules with a particle size of 100-200 μm, and the microcapsules are immersed in a 5% sodium silicate solution for 30 minutes to deposit a nano-SiO2 layer with a thickness of 50-100 nm on the surface of the microcapsules, and the surface is modified with a 0.1 mg / mL lysozyme solution to obtain the lactobacillus acidophilus microcapsule bacterial agent, and the microcapsules are refrigerated at 4° C. for standby use.

8. The method for preparing the soy product plant-based fruit freeze-dried block according to claim 5, characterized in that: In the step 2, before using the pectinase and cellulase, a double-layer embedding treatment is first performed, wherein the inner layer is a liposome embedding layer composed of phosphatidylcholine and cholesterol in a mass ratio of 7:3, and the outer layer is a sodium alginate-chitosan composite microsphere; the composite microsphere degrades at pH ≤ 5.

0.

9. The method for preparing the soy product plant-based fruit freeze-dried block according to claim 8, characterized in that: The double-layer embedding treatment method of pectinase and cellulase comprises the following steps: S1. Liposome inner layer embedding: dissolving phosphatidylcholine and cholesterol in anhydrous ethanol at a mass ratio of 7:3, rotary evaporating at 50°C to form a lipid film, adding a phosphate buffer with a pH of 7.0 to hydrate, and obtaining a liposome solution; dissolving pectinase or cellulase in the liposome solution, emulsifying and homogenizing at 50°C for 10 minutes under nitrogen protection to form an enzyme-liposome complex, and controlling the liposome particle size to be 30-50 μm; S2, outer microsphere coating: the enzyme-liposome complex obtained in S1 was mixed with 2% sodium alginate solution at a volume ratio of 1:5, and dropped into a solidification liquid containing 1.5% CaCl2 and 0.5% chitosan at a voltage of 20 kV and a spray distance of 10 cm through an electrostatic spray device to form sodium alginate-chitosan composite microspheres; after solidification for 30 minutes, the mixture was collected by centrifugation and freeze-dried to obtain a double-layer encapsulated enzyme preparation; The particle size of the composite microspheres is 50-100 μm, and the mass ratio of sodium alginate to chitosan is 3:

1.

10. The method for preparing the soy product plant-based fruit freeze-dried block according to claim 5, characterized in that: The fermentation treatment in step three adopts a dynamic control system, including: real-time monitoring of the pH value and lactic acid concentration of the mixture, and when the lactic acid concentration growth rate is greater than 0.2% / min, automatically reducing the temperature from 36°C to 34°C and increasing the stirring rate by 10-20%.

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