Microcapsule embedding process for maintaining brittleness and flavor of instant konjak product

Abstract

The invention relates to the technical field of food processing, and discloses a microcapsule embedding technology for maintaining the brittleness and flavor of an instant konjac product, and the technology comprises the following steps: S1, preparing a composite wall material; s2, mixing the flavor substance and the functional additive; s3, preparing and embedding the microcapsules; and S4, treating and forming the microencapsulated konjak product. Through the synergistic effect of the composite wall material, the flavor stability and brittleness maintaining capability of the konjak product can be remarkably improved, the shelf life of the product is prolonged, various components in the composite wall material play different functions and complement each other, the loss and oxidation of flavor substances are effectively prevented, and meanwhile, the structural stability of the konjak product is maintained; the microcapsule embedding process is beneficial to keeping the color and taste of the konjak product, consumers can enjoy better experience when eating the konjak product, and part of components in the microcapsules have certain nutrition and health care functions and are beneficial to human health.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, and particularly to a microencapsulation process for maintaining both the crispness and flavor of instant konjac products. Background Art

[0002] Konjac is the only plant that contains a large amount of glucomannan. Konjac not only contains more than 10 kinds of amino acids and various trace elements required by the human body, but also has the characteristics of low protein, low fat, high fiber, strong water absorption, and high expansion rate. In terms of medicinal efficacy, it has various effects such as reducing blood lipid, blood sugar, and blood pressure, detoxifying, losing weight, beautifying, health care, and laxative. Moreover, konjac also has gel property, thickening property, and water retention property, so konjac is often used to prepare foods such as noodles, cold noodles made from bean or sweet potato starch, and rice noodles.

[0003] During the processing and storage of instant konjac products, there are problems of easy loss of crispness and easy dissipation of flavor. Traditional single microcapsule wall materials have limited ability in encapsulating flavor substances and protecting the crispness of products, and it is difficult to comprehensively cope with various changes in complex environments. Different storage conditions and processing processes have different effects on the crispness and flavor of konjac products. Single wall materials cannot provide sufficient protective activity and adaptability. At the same time, the complexity of the interactions and reactions during the microencapsulation process makes it difficult to accurately predict and control the protective performance of microcapsules on konjac products. Therefore, it is urgent to develop a new microencapsulation process to solve these problems. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a microencapsulation process for maintaining both the crispness and flavor of instant konjac products, and solves the problems raised in the above background art.

[0005] The present invention provides the following technical solutions: A microencapsulation process for maintaining both the crispness and flavor of instant konjac products, comprising the following steps: Step S1: Preparation of composite wall materials; Step S2: Mixing of flavor substances and functional additives; Step S3: Preparation and encapsulation of microcapsules; Step S4: Treatment and shaping of microencapsulated konjac products.

[0006] Preferably, step 1 specifically includes: A variety of materials with film-forming properties, water retention properties, and protective functions are compounded. Sodium alginate with a degree of polymerization of 800 - 1200, chitosan with a degree of deacetylation ≥ 90%, β-cyclodextrin with an average molecular weight of 1135 Da, and carboxymethylated starch with a carboxymethyl content of 0.8 - 1.2 are selected as the raw materials for the composite wall material; they are mixed according to a mass ratio of 8:3:2:5, and high-speed stirred for 15 - 20 min under the condition of a rotation speed of 1200 - 1500 r / min to make them fully and evenly dispersed, forming a composite wall material with a synergistic effect.

[0007] Preferably, step 2 specifically includes: Collect the natural spice extracts of star anise and cinnamon, as well as the fruit extracts of strawberry and mango as flavor substances; select citric acid with a mass concentration of 0.3% - 0.5% and sodium bicarbonate with a mass concentration of 0.2% - 0.4% as the crispness-enhancing functional additives; mix the flavor substances and the crispness-enhancing additives according to a mass ratio of flavor substances:crispness-enhancing additives = 3:1 at a temperature of 20 - 25°C and a rotation speed of 800 - 1000 r / min for 10 - 15 min to form a mixture of flavor and functional additives.

[0008] Preferably, step 3 specifically includes: Mix the composite wall material and deionized water according to a mass ratio of 1:10 - 1:12, heat and stir at a temperature of 65 - 75°C and a stirring speed of 600 - 800 r / min for 20 - 30 min until completely dissolved to form a uniform wall material solution; slowly add the material obtained by mixing the flavor and functional additives in step S2 into the wall material solution, and continue to stir for 10 - 15 min to form a mixture; use a pressure spray dryer, under the process conditions of an inlet air temperature of 180 - 200°C, an outlet air temperature of 80 - 90°C, a feeding speed of 20 - 30 mL / min, and an atomization pressure of 3 - 5 MPa, atomize the mixture into tiny droplets with an average particle size of 5 - 15 μm, and the droplets are quickly dried under the action of hot air to form microcapsules, realizing the encapsulation of flavor substances and crispness-enhancing additives.

[0009] Preferably, step 4 specifically includes: After washing fresh konjac, soak it in an alkaline solution (pH value 10 - 11) at a temperature of 80 - 90 °C for 10 - 15 min to peel it, and then cut it into slices with a thickness of 2 - 3 mm; put the cut konjac slices into a solution containing microcapsules with a mass concentration of 5% - 8%, and soak them at a temperature of 20 - 25 °C and a vacuum degree of -0.06 - -0.08 MPa for 30 - 45 min to make the microcapsules fully adhere to the surface and internal pores of the konjac; after draining the konjac slices, pre-freeze them at a pre-freezing temperature of -35 - -40 °C for 2 - 3 h, and then carry out freeze-drying for 12 - 18 h under a vacuum degree of 10 - 30 Pa and a sublimation temperature of -25 - -20 °C; finally, cut and package it with nitrogen filling, and the nitrogen filling amount is 80% - 90% of the packaging volume to obtain a microencapsulated instant konjac product.

[0010] Preferably, the intrinsic viscosity of the sodium alginate is 600 - 800 mPa・s (1% aqueous solution, 25 °C), and the guluronic acid content ≥ 65%; the intrinsic viscosity of the chitosan is 200 - 400 mPa・s (1% acetic acid solution, 25 °C), and the degree of deacetylation is 90% - 95%; the solubility of the β-cyclodextrin is 18.5 - 21.5 g / 100 ml (25 °C), and the inclusion constant ≥ 500 L / mol; the degree of substitution of the carboxymethyl modified starch is 0.8 - 1.0, and the gelatinization temperature is 55 - 65 °C.

[0011] Preferably, the natural flavor extract is obtained by supercritical CO2 extraction, with an extraction pressure of 25 - 30 MPa and an extraction temperature of 40 - 50 °C; the fruit extract adopts a low-temperature vacuum concentration technology, with a concentration temperature ≤ 45 °C and a vacuum degree ≥ 0.09 MPa.

[0012] Preferably, the solid content of the composite wall material solution is 8% - 12%, and the surface tension is 35 - 45 mN / m; the feeding speed of the flavor and functional additive mixture is 5 - 10 mL / min, and the temperature of the wall material solution is maintained at 60 - 65 °C during the feeding process; spray drying uses a two-fluid nozzle with a nozzle aperture of 0.8 - 1.2 mm, and the contact time between the droplets and the hot air is 15 - 30 s; the embedding rate of the formed microcapsules ≥ 90%, the moisture content ≤ 5%, the average particle size is 8 - 12 μm, and the particle size distribution D90 / D10 ≤ 3.0.

[0013] Preferably, the alkaline solution is a mixed solution of calcium hydroxide and sodium carbonate, where the calcium hydroxide concentration is 0.3% - 0.5%, and the sodium carbonate concentration is 0.1% - 0.3%; during the vacuum soaking process, a cyclic vacuum pumping method is adopted, and the vacuum is broken once every 5 - 8 min, and the vacuum breaking pressure is -0.02 - -0.03 MPa.

[0014] The present invention has the following beneficial effects: 1. The microcapsule embedding process for maintaining both crispness and flavor of the instant konjac product can significantly improve the flavor stability and crispness retention ability of the konjac product and extend the shelf life of the product through the synergistic effect of the composite wall material. The components in the composite wall material play different functions and complement each other, effectively preventing the loss and oxidation of flavor substances, while maintaining the structural stability of the konjac product and preventing the crispness from decreasing during storage. Secondly, the microcapsule embedding process helps to maintain the color and taste of the konjac product, so that consumers can enjoy a better experience when eating, and some components in the microcapsules also have certain nutritional and health functions, which are beneficial to human health.

[0015] 2. The microcapsule embedding process for maintaining both crispness and flavor of the instant konjac product is not only easy to operate but also highly feasible and easy to realize industrial production. By adjusting the ratio of the composite wall material, the key process parameters in the microcapsule preparation process, and the meticulous treatment of the konjac product, we can ensure that the microcapsules are evenly dispersed in the konjac product and can give full play to their due role. The implementation of such a process not only significantly improves the production efficiency, but also ensures that the quality of the product is maintained at a high standard during large-scale production, meeting the dual high standards of consumers for food safety and taste.

[0016] 3. The microcapsule encapsulation process for maintaining both crispness and flavor of the instant konjac product can significantly reduce the dependence on and use of other chemical additives in the production process of konjac products by using natural, edible composite wall materials and additives. This method not only helps to reduce the potential health risks caused by the use of chemical substances, but also this natural encapsulation method is more in line with consumers' growing demand for healthy food. In addition, it can effectively improve the overall safety of the product, ensuring that consumers can get health protection while enjoying delicious food. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the process structure of the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] See also Figure 1 A microcapsule embedding process for maintaining the crispness and flavor of an instant konjac product comprises the following steps: Step S1: Preparation of composite wall material; Step S2: Mixing of flavor substances and functional additives; Step S3: Preparation and embedding of microcapsules; Step S4: Treatment and shaping of microencapsulated konjac products; Steps S1 - S4 are carried out in sequence, and the composite wall material prepared in step S1 is used in step S3, the mixture of flavor and functional additives prepared in step S2 is used in step S3, and the microcapsules prepared in step S3 are used in step S4.

[0020] In a preferred embodiment, step 1 specifically includes: Compound multiple materials with film - forming property, water - retaining property and protective function, and select sodium alginate with a polymerization degree of 800 - 1200, chitosan with a deacetylation degree ≥ 90%, β - cyclodextrin with an average molecular weight of 1135Da, and carboxymethyl - modified starch with a carboxymethyl content of 0.8 - 1.2 as raw materials for the composite wall material; mix them according to a mass ratio of 8:3:2:5, and stir at a high speed for 15 - 20 min under the condition of a rotation speed of 1200 - 1500 r / min to make them fully dispersed and uniform, forming a composite wall material with a synergistic effect; Sodium alginate has good gelling and water - retaining properties, chitosan has antibacterial and film - forming characteristics, β - cyclodextrin can effectively embed flavor substances, and modified starch can enhance the stability and mechanical strength of the wall material. The multiple materials cooperate with each other to improve the overall protection ability of the konjac product's crispness and flavor; Sodium alginate can form a thermally irreversible gel under the action of divalent metal ions, and the water - retention rate can reach more than 90% in an environment of 25 - 35°C; the antibacterial activity of chitosan can inhibit the growth of Gram - positive bacteria and Gram - negative bacteria, and the oxygen permeability rate decreases by 60% - 70% after film - forming; the hydrophobic cavity structure of β - cyclodextrin can embed flavor substances, and the embedding rate can reach 75% - 85%; the network structure formed by the molecular modification of modified starch increases the tensile strength of the composite wall material by 40% - 50%. The multiple materials cooperate with each other to improve the overall protection ability of the konjac product's crispness and flavor.

[0021] In a preferred embodiment, step 2 specifically includes: Collect the natural spice extracts of star anise and cinnamon, as well as the fruit extracts of strawberry and mango as flavor substances; select citric acid with a mass concentration of 0.3% - 0.5% and sodium bicarbonate with a mass concentration of 0.2% - 0.4% as the crispness - enhancing functional additives; mix the flavor substances and the crispness - enhancing additives according to a mass ratio of flavor substances: crispness - enhancing additives = 3:1 at a temperature of 20 - 25°C and a rotation speed of 800 - 1000 r / min for 10 - 15 min to form a mixture of flavor and functional additives; In the flavor and function hybrid system, citric acid and sodium bicarbonate undergo an acid-base reaction during subsequent processing, releasing carbon dioxide gas and forming a microporous structure inside the konjac, improving and maintaining the crispness of the product; meanwhile, flavor substances are pre-embedded by β-cyclodextrin to reduce volatilization loss during high-temperature processing; The flavor and function hybrid system not only imparts a unique flavor to konjac products but also improves and maintains the crispness of the products during subsequent processing and storage.

[0022] In a preferred embodiment, step 3 specifically includes: Mix the composite wall material and deionized water at a mass ratio of 1:10 - 1:12, heat and stir at a temperature of 65 - 75°C and a stirring speed of 600 - 800 r / min for 20 - 30 min until completely dissolved to form a uniform wall material solution; slowly add the material obtained by mixing the flavor and function additives prepared in step S2 into the wall material solution, and continue to stir for 10 - 15 min to form a mixture; use a pressure spray dryer, under the process conditions of an inlet air temperature of 180 - 200°C, an outlet air temperature of 80 - 90°C, a feeding speed of 20 - 30 mL / min, and an atomization pressure of 3 - 5 MPa, atomize the mixture into tiny droplets with an average particle size of 5 - 15 μm, and the droplets are rapidly dried under the action of hot air to form microcapsules, realizing the embedding of flavor substances and crispness-enhancing additives; Mix the composite wall material and deionized water at a mass ratio of 1:10 - 1:12, heat and stir at a temperature of 65 - 75°C and a stirring speed of 600 - 800 r / min for 20 - 30 min until completely dissolved to form a uniform wall material solution with a solid content of 8% - 12% and a surface tension of 35 - 45 mN / m; slowly add the flavor and function additive hybrid system prepared in step S2 into the wall material solution at a speed of 5 - 10 mL / min, and keep the temperature of the wall material solution at 60 - 65°C during the addition process, and continue to stir for 10 - 15 min to form a mixture; use a pressure spray dryer equipped with a two-fluid nozzle with an aperture of 0.8 - 1.2 mm, under the process conditions of an inlet air temperature of 180 - 200°C, an outlet air temperature of 80 - 90°C, a feeding speed of 20 - 30 mL / min, an atomization pressure of 3 - 5 MPa, and a contact time of 15 - 30 s between the droplets and hot air, atomize the mixture into tiny droplets with an average particle size of 5 - 15 μm, and the droplets are rapidly dried under the action of hot air to form microcapsules with an embedding rate ≥ 90%, a moisture content ≤ 5%, an average particle size of 8 - 12 μm, and a particle size distribution D90 / D10 ≤ 3.0, realizing the embedding of flavor substances and crispness-enhancing additives.

[0023] In a preferred embodiment, step 4 specifically includes: After cleaning fresh konjac, soak it in an alkaline solution (pH value 10 - 11) at a temperature of 80 - 90 °C for 10 - 15 min to peel it, and then cut it into slices with a thickness of 2 - 3 mm; put the cut konjac slices into a solution containing microcapsules with a mass concentration of 5% - 8%, and soak them at a temperature of 20 - 25 °C and a vacuum degree of -0.06 - -0.08 MPa for 30 - 45 min to make the microcapsules fully adhere to the surface and internal pores of the konjac; after draining the konjac slices, pre-freeze them at a pre-freezing temperature of -35 - -40 °C for 2 - 3 h, and then carry out freeze-drying for 12 - 18 h under a vacuum degree of 10 - 30 Pa and a sublimation temperature of -25 - -20 °C; finally, cut and use nitrogen filling packaging, and the nitrogen filling amount is 80% - 90% of the packaging volume to obtain a microencapsulated instant konjac product; Freeze-drying is divided into three stages: the first stage of sublimation drying temperature is -30 - -25 °C, and the time is 6 - 8 h; the second stage of desorption drying temperature is -15 - -10 °C, and the time is 4 - 6 h; the third stage of desorption drying temperature is 0 - 5 °C, and the time is 2 - 4 h; The microencapsulated instant konjac product is stored for 30 days under the accelerated storage conditions of 37 °C and a relative humidity of 75%, and the crispness retention rate ≥ 85%, and the flavor substance retention rate ≥ 80%; Through the protection of the microcapsules, the microencapsulated instant konjac product effectively maintains the crispness and flavor during processing and storage.

[0024] In a preferred embodiment, the intrinsic viscosity of sodium alginate is 600 - 800 mPa・s (1% aqueous solution, 25 °C), and the guluronic acid content ≥ 65%; the intrinsic viscosity of chitosan is 200 - 400 mPa・s (1% acetic acid solution, 25 °C), and the degree of deacetylation is 90% - 95%; the solubility of β-cyclodextrin is 18.5 - 21.5 g / 100 ml (25 °C), and the inclusion constant ≥ 500 L / mol; the substitution degree of carboxymethyl modified starch is 0.8 - 1.0, and the gelatinization temperature is 55 - 65 °C; The heavy metal content of sodium alginate ≤ 10 mg / kg, and the arsenic content ≤ 2 mg / kg; the microbial indicators of chitosan need to meet the GB1903.12 - 2016 standard, the total number of colonies ≤ 1000 CFU / g, and the coliform group ≤ 3 MPN / 100 g; the drying loss of β-cyclodextrin ≤ 10.0%, and the incineration residue ≤ 0.5%; the sulfur dioxide residue of carboxymethyl modified starch ≤ 30 mg / kg.

[0025] In a preferred embodiment, the natural flavor extract is obtained by supercritical CO2 extraction, with an extraction pressure of 25 - 30 MPa and an extraction temperature of 40 - 50 °C; the fruit extract adopts low-temperature vacuum concentration technology, with a concentration temperature ≤ 45 °C and a vacuum degree ≥ 0.09 MPa.

[0026] In a preferred embodiment, the solid content of the composite wall material solution is 8% - 12%, and the surface tension is 35 - 45 mN / m; the feeding rate of the material after mixing the flavor and functional additives is 5 - 10 mL / min, and the temperature of the wall material solution is maintained at 60 - 65 °C during the feeding process; two-fluid nozzles are used for spray drying, the nozzle aperture is 0.8 - 1.2 mm, and the contact time between the droplets and the hot air is 15 - 30 s; the embedding rate of the formed microcapsules is ≥90%, the moisture content is ≤5%, the average particle size is 8 - 12 μm, and the particle size distribution D90 / D10 ≤ 3.0; After the film formation of the wall material of the microcapsules, the oxygen permeability ≤ 10 cm³ / (m²·24 h·0.1 MPa), and the water vapor permeability ≤ 5 g / (m²·24 h); the glass transition temperature of the microcapsules ≥ 60 °C.

[0027] In a preferred embodiment, the alkaline solution is a mixed solution of calcium hydroxide and sodium carbonate, where the concentration of calcium hydroxide is 0.3% - 0.5%, and the concentration of sodium carbonate is 0.1% - 0.3%; the cyclic vacuum pumping method is adopted during the vacuum soaking process, and the vacuum is broken every 5 - 8 min, and the vacuum breaking pressure is -0.02 - -0.03 MPa; The rehydration ratio of the freeze-dried konjac slices ≥ 3:1, and the rehydration time ≤ 10 min; during the storage of the product after nitrogen filling packaging, the oxygen concentration in the package ≤ 2%; Before nitrogen filling packaging, the product is sterilized by γ-ray irradiation, and the irradiation dose is 3 - 5 kGy.

[0028] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0029] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A microencapsulation process for maintaining both crispness and flavor of instant konjac products, characterized in that, It includes the following steps: Step S1: Preparation of composite wall material; Step S2: Mixing of flavor substances and functional additives; Step S3: Preparation and embedding of microcapsules; Step S4: Processing and shaping of microencapsulated konjac products.

2. The microcapsule embedding process for maintaining both crispness and flavor of an instant konjac product according to claim 1, characterized in that: Step 1 specifically includes: Compound a variety of materials with film-forming, water-retaining and protective functions, and select sodium alginate with a polymerization degree of 800 - 1200, chitosan with a deacetylation degree ≥ 90%, β-cyclodextrin with an average molecular weight of 1135 Da, and carboxymethyl modified starch with a carboxymethyl content of 0.8 - 1.2 as raw materials for the composite wall material; mix them according to a mass ratio of 8:3:2:5, and stir at a high speed for 15 - 20 min under the condition of a rotation speed of 1200 - 1500 r / min to make them fully dispersed and uniform, forming a composite wall material with a synergistic effect.

3. The microencapsulation process for maintaining both crispness and flavor of an instant konjac product according to claim 1, characterized in that: Step 2 specifically includes: Collect the natural spice extracts of star anise and cinnamon, as well as the fruit extracts of strawberry and mango as flavor substances; select citric acid with a mass concentration of 0.3% - 0.5% and sodium bicarbonate with a mass concentration of 0.2% - 0.4% as the crispness-enhancing functional additives; mix the flavor substances and the crispness-enhancing additives according to a mass ratio of flavor substances:crispness-enhancing additives = 3:1 at a temperature of 20 - 25°C and a rotation speed of 800 - 1000 r / min for 10 - 15 min to form a mixture of flavor and functional additives.

4. A microencapsulation process for maintaining both crispness and flavor of an instant konjac product according to claim 1, characterized in that: Step 3 specifically includes: Mix the composite wall material and deionized water according to a mass ratio of 1:10 - 1:12, heat and stir at a temperature of 65 - 75°C and a stirring speed of 600 - 800 r / min for 20 - 30 min until completely dissolved to form a uniform wall material solution; slowly add the material obtained by mixing the flavor and functional additives prepared in Step S2 into the wall material solution, and continue to stir for 10 - 15 min to form a mixture; use a pressure spray dryer, under the process conditions of an inlet air temperature of 180 - 200°C, an outlet air temperature of 80 - 90°C, a feeding speed of 20 - 30 mL / min, and an atomization pressure of 3 - 5 MPa, atomize the mixture into tiny droplets with an average particle size of 5 - 15 μm, and the droplets are quickly dried under the action of hot air to form microcapsules, realizing the embedding of flavor substances and crispness-enhancing additives.

5. A microencapsulation process for maintaining both crispness and flavor of an instant konjac product according to claim 1, characterized in that: Step 4 specifically includes: After washing fresh konjac, soak it in an alkaline solution (pH value 10 - 11) at a temperature of 80 - 90°C for 10 - 15 min to peel it, and then cut it into slices with a thickness of 2 - 3 mm; put the cut konjac slices into a solution containing microcapsules with a mass concentration of 5% - 8%, and soak them at a temperature of 20 - 25°C and a vacuum degree of -0.06 - -0.08 MPa for 30 - 45 min to make the microcapsules fully adhere to the surface and internal pores of the konjac; after draining the konjac slices, pre-freeze them at a pre-freezing temperature of -35 - -40°C for 2 - 3 h, and then carry out freeze-drying at a vacuum degree of 10 - 30 Pa and a sublimation temperature of -25 - -20°C for 12 - 18 h; finally, cut and package them with nitrogen filling, and the nitrogen filling amount is 80% - 90% of the packaging volume to obtain an instant microencapsulated konjac product.

6. A microcapsule embedding process for maintaining both crispness and flavor of an instant konjac product according to claim 2, characterized in that: The intrinsic viscosity of the sodium alginate is 600 - 800 mPa・s (1% aqueous solution, 25 °C), and the guluronic acid content is ≥ 65%; the intrinsic viscosity of the chitosan is 200 - 400 mPa・s (1% acetic acid solution, 25 °C), and the degree of deacetylation is 90% - 95%; the solubility of the β-cyclodextrin is 18.5 - 21.5 g / 100 ml (25 °C), and the inclusion constant is ≥ 500 L / mol; the substitution degree of the carboxymethyl modified starch is 0.8 - 1.0, and the gelatinization temperature is 55 - 65 °C.

7. The microencapsulation process for maintaining both crispness and flavor of an instant konjac product according to claim 3, characterized in that: The natural flavor extract is obtained by supercritical CO2 extraction, with an extraction pressure of 25 - 30 MPa and an extraction temperature of 40 - 50 °C; the fruit extract adopts the low-temperature vacuum concentration technology, with a concentration temperature ≤ 45 °C and a vacuum degree ≥ 0.09 MPa.

8. The microencapsulation process for maintaining both crispness and flavor of an instant konjac product according to claim 4, characterized in that: The solid content of the composite wall material solution is 8% - 12%, and the surface tension is 35 - 45 mN / m; the feeding rate of the flavor and functional additive mixture is 5 - 10 mL / min, and the temperature of the wall material solution is maintained at 60 - 65 °C during the feeding process; two-fluid nozzles are used for spray drying, the nozzle aperture is 0.8 - 1.2 mm, and the contact time between the droplets and the hot air is 15 - 30 s; the embedding rate of the formed microcapsules is ≥ 90%, the moisture content is ≤ 5%, the average particle size is 8 - 12 μm, and the particle size distribution D90 / D10 ≤ 3.

0.

9. The microcapsule embedding process for maintaining both crispness and flavor of an instant konjac product according to claim 5, characterized in that: The alkaline solution is a mixed solution of calcium hydroxide and sodium carbonate, where the concentration of calcium hydroxide is 0.3% - 0.5% and the concentration of sodium carbonate is 0.1% - 0.3%; the cyclic vacuum pumping method is adopted during the vacuum soaking process, and the vacuum is broken once every 5 - 8 min, with a vacuum breaking pressure of -0.02 - -0.03 MPa.

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