A swallowable pea protein-based composite gel based on coaxial 3D printing and a preparation method and application thereof

Abstract

The application discloses a swallowable pea protein-based composite gel based on coaxial 3D printing and a preparation method and application thereof, and belongs to the field of food processing. The swallowable pea protein-based composite gel is prepared by simultaneously depositing a shell layer hydrogel and a core layer emulsion gel through coaxial 3D printing technology to prepare a swallowable composite gel structure, which can be a delivery carrier for active ingredients. Due to the barrier effect of the shell hydrogel, the stability of nutrients can be effectively improved, the activity of functional factors can be maintained, and the development of a nutrition-enhanced swallowable gel food is realized.

Description

Technical Field

[0001] This invention relates to an easily swallowable pea protein-based composite gel based on coaxial 3D printing, its preparation method and application, belonging to the field of food processing. Background Technology

[0002] 3D printing for encapsulating functional active ingredients or drugs is a novel technology that not only enables the creation of highly precise and complex structures but also allows for the precise customization and control of the targeted release of active ingredients or drugs, thereby improving their bioavailability and functionality. It holds immense potential in the food and pharmaceutical industries. In particular, fortified foods developed for individuals with swallowing disorders can be personalized with 3D printing, allowing for the design of food formulations or the addition of functional factors and nutrients based on the patient's individual nutritional status. This provides a new solution to the common nutritional deficiencies faced by patients with swallowing disorders.

[0003] For example, Chinese patent CN115152995A discloses a method for preparing easily absorbed 3D printed products rich in carotenoids. Specifically, protein is dispersed in a phosphate buffer solution to form an aqueous phase, and carotenoids are dissolved in edible oil with ultrasonic treatment to form an oil phase. The aqueous and oil phases are mixed evenly, and polysaccharides are added, homogenized, and heated in a water bath to form a gel. Then, the product is formed by 3D printing.

[0004] For example, Chinese patent CN118766054A discloses a method for preparing shepherd's purse gel for 3D printing with high freeze-thaw stability. Specifically, pea protein is dispersed in water, the pH is adjusted to 7-8, homogenized, and fully hydrated to obtain a pea protein suspension; galactomannan is added to the pea protein suspension, mixed evenly, homogenized at high speed, sealed with plastic wrap, and heated in a water bath to obtain a pea protein-galactomannan mixed solution; shepherd's purse powder is mixed with the pea protein-galactomannan mixed solution, homogenized at high speed, and subjected to a water bath thermal crosslinking reaction, then cooled at room temperature to obtain shepherd's purse gel for 3D printing.

[0005] Although adding functional factors or nutrients directly to printing ink for 3D printing can achieve precise release of functional factors or nutrients and improve their bioavailability and functionality, some problems still exist. For example, the stability and activity of functional factors may decrease due to heating, irradiation and other conditions during subsequent processing. Summary of the Invention

[0006] [Technical Issues] While existing 3D printed products can achieve precise release of functional factors or nutrients, improving their bioavailability and functionality, there are still some shortcomings. For example, during subsequent processing, the stability and activity of functional factors or nutrients may decrease due to the influence of conditions such as heating or irradiation.

[0007] [Technical Solution] To address the shortcomings of existing technologies, the present invention aims to provide an easily swallowable pea protein-based composite gel based on coaxial 3D printing, its preparation method, and its application. Coaxial 3D printing allows for the simultaneous extrusion of inner and outer layer materials through a coaxial nozzle, precisely constructing a "core-shell" structure. Nutrients are encapsulated in the core layer, while the outer layer acts as a protective barrier, enabling the directional release of nutrients. Furthermore, the shell layer effectively isolates oxygen, light, moisture, or stomach acid, improving the stability of nutrients.

[0008] In addition, coaxial 3D printing can extrude multiple components through different layer combinations to produce products with more ideal appearance and texture, which can be used to develop modified foods that are easy to chew, easy to swallow, and have a soft texture.

[0009] This invention utilizes coaxial 3D printing technology to simultaneously deposit a hydrogel shell and an emulsion gel core to prepare an easily swallowable composite gel structure, which serves as a delivery carrier for active ingredients, thereby improving the stability of the active ingredients and providing a reference for the development of nutritionally fortified easily swallowable foods.

[0010] To achieve the above objectives, the following technical solution is provided: The first objective of this invention is to provide a method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing, comprising the following steps: (1) Mix pea protein and polysaccharide evenly to form the shell hydrogel phase; (2) Using pea protein and carrageenan as the aqueous phase and vegetable oil as the oil phase, an emulsion gel was obtained by high-speed shearing using a shearing machine, which served as the core layer; (3) A composite gel was obtained by simultaneously depositing the shell hydrogel phase and the core material through coaxial 3D printing; (4) Gel the composite gel obtained in step (3) to obtain an easy-to-swallow pea protein-based composite gel.

[0011] In one embodiment, the polysaccharide in step (1) includes one or more of corn starch, carrageenan, and sodium alginate.

[0012] In one embodiment, the mass fraction of pea protein in the hydrogel phase of step (1) is 20%-25%.

[0013] In one embodiment, the mass fraction of polysaccharides in the hydrogel phase of step (1) is 0.1% to 10%.

[0014] In one embodiment, when the polysaccharide in step (1) is corn starch, the mass fraction of corn starch in the hydrogel phase is 1% to 10%.

[0015] In one embodiment, when the polysaccharide in step (1) is carrageenan, the mass fraction of carrageenan in the hydrogel phase is 0.1% to 1%.

[0016] In one embodiment, when the polysaccharide in step (1) is sodium alginate, the mass fraction of sodium alginate in the hydrogel phase is 0.5%~1%.

[0017] In one embodiment, the specific preparation of the hydrogel phase in step (1) is to prepare a polysaccharide dispersion and then add pea protein to the polysaccharide dispersion and mix them evenly.

[0018] In one embodiment, the mass fraction of pea protein in the aqueous phase of step (2) is 5-10%, and the mass fraction of carrageenan is 0.5-1.5%.

[0019] In one embodiment, the vegetable oil in step (2) includes any one or more of soybean oil, rapeseed oil, and corn oil.

[0020] In one embodiment, the volume ratio of the aqueous phase to the oil phase in step (2) is 1:1.

[0021] In one embodiment, the stirring speed of the shearing machine in step (2) is 9000~12000 rpm, and the time is 1~3 min.

[0022] In one embodiment, the oil phase in step (2) further includes functional active substances.

[0023] In one embodiment, the functional active substance includes one or more of curcumin, lycopene, and β-carotene.

[0024] In one embodiment, the oil phase in step (2) includes curcumin, and the concentration of curcumin is 2 mg / mL to 4 mg / mL.

[0025] In one embodiment, the parameters of the coaxial 3D printing in step (3) are as follows: the coaxial 3D printing needle is a 14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm, the moving speed of the 3D printer needle is 6~8 mm / s, and the pushing speed of the peristaltic pump is 1~2 mL / min.

[0026] In one embodiment, the gelation in step (4) can be carried out by means of heating and cooling and / or soaking in an ionic solution.

[0027] In one embodiment, the heating and cooling conditions are as follows: heating temperature is 80℃~95℃, time is 10 min~15 min, and cooling temperature is 2℃~10℃.

[0028] In one embodiment, the ionic solution is a CaCl2 solution.

[0029] In one embodiment, the mass fraction of the CaCl2 solution is 1% to 2%.

[0030] A second objective of this invention is to provide an easily swallowable pea protein-based composite gel obtained by the preparation method described above.

[0031] A third objective of this invention is to provide an application of the aforementioned easily swallowable pea protein-based composite gel in 3D printed products.

[0032] A fourth objective of this invention is to provide a method for improving the stability and activity of functional active factors, the method comprising the following steps: (1) Mix pea protein and polysaccharide evenly to form the shell hydrogel phase; (2) Using pea protein and carrageenan as the aqueous phase and vegetable oil containing functional active factors as the oil phase, an emulsion gel was obtained by high-speed shearing using a shearing machine, which served as the core layer. (3) A composite gel was obtained by simultaneously depositing the shell hydrogel phase and the core material through coaxial 3D printing; (4) Gel the composite gel obtained in step (3) to obtain an easy-to-swallow pea protein-based composite gel.

[0033] In one embodiment, the functional active factor includes one or more of curcumin, lycopene, and β-carotene.

[0034] [Beneficial Effects] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses coaxial 3D printing to simultaneously deposit emulsion gel and hydrogel to construct a composite gel structure, which effectively controls the texture characteristics and swallowing level of the gel; (2) The coaxial 3D printed composite gel prepared by the present invention can be used as a nutrient delivery carrier. Due to the barrier effect of the outer shell hydrogel, the stability of nutrients can be effectively improved, and the development of nutrient-fortified easy-to-swallow gel foods can be realized. (3) The present invention uses coaxial 3D printing to construct gel structures, which can realize personalized customization of gel structure and shape, enhance visual appeal, and provide a method reference for sensory enhancement of easy-to-swallow foods. Attached Figure Description

[0035] Figure 1 IDSSI images of the composite gels prepared in Examples 2, 5 and 7; (a) spoon compression; (b) fork compression; Figure 2 The graph shows the force and fitted work curves during the multiple chewing cycles of the composite gels prepared in Examples 2, 5 and 7. Figure 3 Oral friction curves of the composite gels prepared in Examples 2, 5, and 7; Figure 4 The retention rate of curcumin in the composite gels prepared in Examples 2, 5, and 7 and Comparative Examples 1-3 under different treatment conditions is shown in the figure; (a) heating; (b) ultraviolet irradiation. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] The testing method involved in this invention: 1. Texture determination: The hardness, adhesion, and cohesiveness of the samples were tested using a texture analyzer equipped with a JA2040P-S probe. The sample was placed into a standard test cup with a diameter of 40 mm and a depth of 20 mm, filling it to a height of 15 mm above the inner mark. A compression test was conducted using a 20 mm dedicated cylindrical probe at a speed of 10 mm / s and a compression distance of 15 mm. The hardness, adhesion, and cohesion of the sample were tested. The chewing and swallowing characteristics of the composite gel were determined according to food association standards and the texture distinction of silver-friendly foods.

[0038] 2. IDSSI measurements were performed using an A / IDDSI probe configured with a texture analyzer. The probe is designed in the shape of an arc and a fork, mimicking the thumb press and fork compression in the original test. When the probe moves downward at a speed of 2 mm / s to a force of 3.825 N, it stops moving and holds this position for 10 s, then moves back to the starting position at a speed of 10 mm / s.

[0039] 3. Multiple oral bionic chewing tests were conducted using a texture analyzer equipped with a MEC probe. Weigh 15 g of sample and add 5 mL of artificial saliva for multiple compressions to simulate oral chewing. During the test, the probe moves at a speed of 5 mm / s, the compression distance is 93 mm, and the compression cycle is 30 times. Calculate the work done during the compression process based on the force-distance curve.

[0040] 4. Oral friction test: Oral friction test was performed using a texture analyzer equipped with the H / STM model device. Weigh 5 g of the sample after multiple chewing tests, add 2.5 mL of artificial saliva and mix well. Use a glass rod to spread the sample evenly on the PDMS surface. Set the probe sliding distance to 50 mm and the sliding speed to 2 mm / s. To avoid the influence of gravity, ensure that the probe moves horizontally.

[0041] 5. The stability of curcumin was assessed by UV and temperature stability tests. UV stability: 1 g of the composite gel sample was weighed and placed into a 15 mL transparent sealed tube, then irradiated under UV light. Samples were taken at 0 h, 12 h, 24 h, 36 h, and 48 h. 5 mL of anhydrous ethanol was added to each sample, and the mixture was stirred and vortexed to dissolve the curcumin. After dilution and centrifugation, the curcumin concentration in the sample was calculated by measuring the absorbance, thus determining the curcumin retention rate.

[0042] Temperature stability: 1 g of the composite gel sample was weighed and placed into a 15 mL transparent sealed tube. Samples were taken after heating at 70ºC for 0 h, 2 h, 4 h, 6 h, and 8 h. Subsequent processing was the same as the UV stability test method described above. The control sample was a core emulsion gel loaded with curcumin. The curcumin retention rate was calculated using the following formula.

[0043]

[0044] In the formula, C0 is the initial concentration of curcumin in the sample (0 h), and C t The concentration of curcumin in samples after processing at different times.

[0045] Example 1 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharide as a shell Prepare a corn starch dispersion with a mass fraction of 3%, then add pea protein to the corn starch dispersion, wherein the mass fraction of pea protein is 24%; stir with a glass rod until the pea protein and corn starch are evenly mixed to form the shell material; (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel as the core material for coaxial printing. (3) Load the shell material from step (1) and the core material from step (2) into the printing cylinder respectively, and print them using a coaxial 3D printer; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min; (4) Heat the printed product in a 90ºC water bath for 10 min, then place it in a 4ºC refrigerator. After cooling, the carrageenan in the core layer gels to form an emulsion gel, and the corn starch and pea protein in the shell layer form a hydrogel after heating and cooling.

[0046] Example 2 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharide as a shell Prepare a corn starch dispersion with a mass fraction of 5%, then add pea protein to the corn starch dispersion, wherein the mass fraction of pea protein is 24%; stir with a glass rod until the pea protein and corn starch are evenly mixed to form the shell material; (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel as the core material for coaxial printing. (3) Load the shell material from step (1) and the core material from step (2) into the printing cylinder respectively, and print them using a coaxial 3D printer; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min; (4) Heat the printed object in a 90ºC water bath for 10 min, then place it in a 4ºC refrigerator. After cooling, the carrageenan in the core layer gels to form an emulsion gel, and the corn starch and pea protein in the shell layer form a hydrogel after heating and cooling.

[0047] Example 3 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharides as the shell Prepare a corn starch dispersion with a mass fraction of 10%, then add pea protein to the corn starch dispersion, wherein the mass fraction of pea protein is 24%; stir with a glass rod until the pea protein and polysaccharide are evenly mixed to serve as the shell material; (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel as the core layer material for coaxial printing. (3) Load the shell material from step (1) and the core material from step (2) into the printing cylinder respectively, and print them using a coaxial 3D printer; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min; (4) Heat the printed object in a 90ºC water bath for 10 min, then place it in a 4ºC refrigerator. After cooling, the carrageenan in the core layer gels to form an emulsion gel, and the corn starch and pea protein in the shell layer form a hydrogel after heating and cooling.

[0048] Example 4 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharides as the shell A carrageenan dispersion with a mass fraction of 0.3% was prepared, and then pea protein was added to the carrageenan dispersion, wherein the mass fraction of pea protein was 24%; the mixture was stirred with a glass rod until the pea protein and polysaccharide were evenly mixed and used as the printing material for the shell layer. (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel as the core layer material for coaxial printing. (3) Load the shell material from step (1) and the core material from step (2) into the printing cylinder respectively, and print them using a coaxial 3D printer; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min; (4) Heat the printed object in a 90ºC water bath for 10 min, then place it in a 4ºC refrigerator. After cooling, the carrageenan in the core layer gels to form an emulsion gel, and the carrageenan and pea protein in the shell layer form a hydrogel after heating and cooling.

[0049] Example 5 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharide as a shell A carrageenan dispersion with a mass fraction of 0.5% was prepared, and then pea protein was added to the carrageenan dispersion, wherein the mass fraction of pea protein was 24%; the mixture was stirred with a glass rod until the pea protein and polysaccharide were evenly mixed and used as the printing material for the shell layer. (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase. Soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel as the core material for coaxial printing. (3) Load the shell material from step (1) and the core material from step (2) into the printing cylinder respectively, and print them using a coaxial 3D printer; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min; (4) Heat the printed object in a 90ºC water bath for 10 min, then place it in a 4ºC refrigerator. After cooling, the carrageenan in the core layer gels to form an emulsion gel, and the carrageenan and pea protein in the shell layer form a hydrogel after heating and cooling.

[0050] Example 6 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharide as a shell A carrageenan dispersion with a mass fraction of 1.0% was prepared, and then pea protein was added to the carrageenan dispersion, wherein the mass fraction of pea protein was 24%; the mixture was stirred with a glass rod until the pea protein and polysaccharide were evenly mixed and used as the printing material for the shell layer. (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel, which was used as the core layer material for coaxial printing. (3) Load the shell material from step (1) and the core material from step (2) into the printing cylinder respectively, and print them using a coaxial 3D printer; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min; (4) Heat the printed object in a 90ºC water bath for 10 min, then place it in a 4ºC refrigerator. After cooling, the carrageenan in the core layer gels to form an emulsion gel, and the carrageenan and pea protein in the shell layer form a hydrogel after heating and cooling.

[0051] Example 7 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharide as a shell Prepare a sodium alginate solution with a mass fraction of 0.5%, and then add pea protein to the sodium alginate solution, wherein the mass fraction of pea protein is 24%; stir with a glass rod until the pea protein and polysaccharide are evenly mixed as the printing material for the shell layer; (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel as the core layer material for coaxial printing. (3) Load the shell material from step (1) and the core material from step (2) into the printing cylinder respectively, and print them using a coaxial 3D printer; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min; (4) The printed object was heated in a 90ºC water bath for 10 min, and then placed in a 4ºC refrigerator. After cooling, the carrageenan in the core layer gelled to form an emulsion gel. After the sample cooled, it was then soaked in a 2% CaCl2 solution for 6 h to allow the sodium alginate to react with the CaCl2. 2+ Hydrogels are formed by gelling the shell layer through ionic cross-linking.

[0052] Example 8 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharide as a shell Prepare a sodium alginate solution with a mass fraction of 0.8%, and then add pea protein to the sodium alginate solution, wherein the mass fraction of pea protein is 24%; stir with a glass rod until the pea protein and polysaccharide are evenly mixed as the printing material for the shell layer; (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel as the core material for coaxial printing. (3) Load the shell material from step (1) and the core material from step (2) into the printing cylinder respectively, and print them using a coaxial 3D printer; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min; (4) The printed object was heated in a 90ºC water bath for 10 min, and then placed in a 4ºC refrigerator. After cooling, the carrageenan in the core layer gelled to form an emulsion gel. After the sample cooled, it was then soaked in a 2% CaCl2 solution for 6 h to allow the sodium alginate to react with the CaCl2. 2+ Hydrogels are formed by gelling the shell layer through ionic cross-linking.

[0053] Example 9 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharide as a shell Prepare a sodium alginate solution with a mass concentration of 1.0%, and then add pea protein to the sodium alginate solution, wherein the mass fraction of pea protein is 24%; stir with a glass rod until the pea protein and polysaccharide are evenly mixed as the printing material for the shell layer; (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel as the core material for coaxial printing. (3) Load the shell material from step (1) and the core material from step (2) into the printing cylinder respectively, and print them using a coaxial 3D printer; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min; (4) The printed object was heated in a 90ºC water bath for 10 min, and then placed in a 4ºC refrigerator. After cooling, the carrageenan in the core layer gelled to form an emulsion gel. After the sample cooled, it was then soaked in a 2% CaCl2 solution for 6 h to allow the sodium alginate to react with the CaCl2. 2+ Hydrogels are formed by gelling the shell layer through ionic cross-linking.

[0054] Comparative Example 1 A method for preparing a pea protein-based emulsion includes the following steps: A mixed dispersion containing 5% pea protein and 0.5% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 4 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10,000 rpm for 3 min to obtain an oil-in-water (O / W) emulsion.

[0055] Comparative Example 2 A method for preparing a pea protein-based emulsion gel includes the following steps: (1) Prepare a mixed dispersion containing 5% pea protein and 0.5% carrageenan as the aqueous phase and soybean oil as the oil phase. Add curcumin to the soybean oil at a concentration of 4 mg / mL in advance and stir to dissolve it. Mix the aqueous phase and oil phase at a volume ratio of 1:1 and shear at 10000 rpm for 3 min to obtain an oil-in-water (O / W) emulsion. (2) Heat the oil-in-water emulsion from step (1) in a 90°C water bath for 10 min, then place it in a 4°C refrigerator. After cooling, the carrageenan gels to form an emulsion gel.

[0056] Comparative Example 3 A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing includes the following steps: (1) A hydrogel composed of pea protein and polysaccharide as a shell A carrageenan dispersion with a mass fraction of 0.5% was prepared, and then pea protein was added to the carrageenan solution, wherein the mass fraction of pea protein was 24%; the mixture was stirred with a glass rod until the pea protein and polysaccharide were evenly mixed and used as the printing material for the shell layer; (2) Preparation of pea protein-carrageenan emulsion gel as core layer A mixed dispersion containing 5% pea protein and 1% carrageenan was prepared as the aqueous phase, and soybean oil was used as the oil phase. Curcumin was added to the soybean oil at a concentration of 2 mg / mL in advance and stirred to dissolve it. The aqueous phase and oil phase were mixed at a volume ratio of 1:1 and sheared at 10000 rpm for 2 min to obtain an oil-in-water (O / W) emulsion gel as the core layer material for coaxial printing. (3) The shell material from step (1) and the core material from step (2) are respectively loaded into the printing barrel and printed using a coaxial 3D printer to obtain a composite gel; the coaxial 3D printing needle (14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm), the moving speed of the 3D printer needle is 6 mm / s, and the pushing speed of the peristaltic pump is 1 mL / min.

[0057] Results Analysis 1. The texture of the pea protein-based composite gels prepared in the examples was differentiated, and the results are shown in Table 1: Table 1. Texture distinction of pea protein-based complex gels

[0058] Remarks: [1] Effects of high pressure on the textural and sensory properties of minced fish meat gels for the dysphagia diet [M]; [2] The effect of aging on mastication and swallowing parameters according to the hardnesschange of solid food [J]. As shown in Table 1, Examples 1, 2, 4, and 5 can all be crushed by the tongue. These foods do not require biting or chewing, which may be suitable for people with tooth loss, weak chewing efficiency, or difficulty swallowing liquid foods. With increasing corn starch or carrageenan concentration, the chewing characteristics of the samples transitioned from "tongue crushing" to "gingival chewing," indicating that the samples require a small amount of chewing before swallowing. For Examples 7-9, with increasing sodium alginate concentration, the chewing characteristics transitioned from "gingival chewing" to "easy chewing." For the composite gels formed by the three polysaccharides and pea protein, the type and concentration of polysaccharides had little effect on the adhesion and cohesiveness levels of the samples. According to the determination results of special dietary foods for patients with dysphagia, both adhesion and cohesiveness belonged to levels II and I, respectively. Comparative Examples 1 and 2, lacking an outer coating, had insufficient mechanical strength to support the integrity of the print, thus failing to maintain the 3D printed shape. Because Comparative Examples 1 and 2 lack a shell, they exhibit a softer texture. Comparative Example 3, due to the absence of heating, does not have a gelled carrageenan, and therefore has a softer texture than Example 5.

[0059] 2. IDSSI analysis was performed on the composite gels prepared in Examples 2, 5, and 7. Figure 1 The composite gels of Examples 2, 5, and 7 are shown to have low hardness and a soft texture. According to the IDSSI rating, they can be classified as the texture category of IDSSI Level 5 food. This type of gel texture does not require biting during consumption and can be swallowed with only a small amount of chewing.

[0060] 3. Simulated oral chewing analysis was performed on the composite gels prepared in Examples 2, 5, and 7. Table 2. Analysis of simulated chewing parameters of pea protein-based composite gel

[0061] Figure 2 Table 2 shows the correlation coefficients (R²) of the composite gels from Examples 2, 5, and 7. 2 The values ​​were 1.00, 0.99, and 0.95, respectively, indicating a good curve fitting effect. The sample experienced the greatest force and performed the most work during the first chewing motion upon entering the oral cavity. After the first chewing, the force applied to break down the sample gradually decreased. After 3-5 cycles, the force applied to the sample reached a stable value, indicating that the sample was broken down and transformed into a swallowable bolus. Example 7 had a harder texture compared to Examples 2 and 5, requiring a greater initial chewing force. The minimum chewing work (W) for Examples 2, 5, and 7 is shown in the table. inf The W values ​​for Example 4 are 0.4 J, 0.4 J, and 0.8 J, respectively. infMaximum. Examples 2, 5, and 7 all exhibited a significant work-softening effect during the extrusion cycle; that is, the required extrusion force and work gradually decreased with increasing chewing frequency. This indicates that the sample's structure changes during chewing, resulting in a softer texture that is easier to deform and swallow.

[0062] 4. Oral friction analysis was performed on the composite gels prepared in Examples 2, 5, and 7. Table 3. Analysis of oral friction parameters of soybean protein-based composite gel

[0063] Figure 3 Table 3 shows that the static friction and average friction of Examples 2, 5, and 7 are all less than 0.1 N, indicating good lubrication. The coefficient of friction is the ratio of average friction (N) to surface load (N). Examples 2, 5, and 7 all have relatively low coefficients of friction, indicating that the samples can maintain good lubrication during oral cavity processing.

[0064] 5. Nutrient stability analysis was performed on the composite gels prepared in Examples 2, 5, and 7. The results are as follows Figure 4 As shown, the thermal and photostability of curcumin loaded in Examples 2, 5, and 7 were significantly improved. After heating at 70ºC for 8 h, the curcumin loaded in Examples 2, 5, and 7 retained 63.61%, 73.62%, and 68.09%, respectively, which were higher than the retention rates of curcumin in Comparative Examples 1, 2, and 3. Similarly, after 48 h of UV irradiation, the curcumin retention rates in Examples 2, 5, and 7 were above 55%, also higher than the retention rates of curcumin in Comparative Examples 1, 2, and 3. This indicates that the core-shell structured composite gel produced by coaxial 3D printing, due to the shielding effect of the outer shell, hinders the transmission of some temperature and UV radiation, reducing the degradation of curcumin, thus resulting in higher stability of curcumin. These results suggest that this composite gel has significant application potential in the protection and delivery of functional components.

[0065] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing an easily swallowable pea protein-based composite gel based on coaxial 3D printing, characterized in that, The method includes the following steps: (1) Mix pea protein and polysaccharide evenly to form the shell hydrogel phase; The polysaccharide includes one or more of corn starch, carrageenan, and sodium alginate; The mass fraction of pea protein in the hydrogel phase is 20%~25%; The mass fraction of polysaccharides in the hydrogel phase is 0.1%~10%; (2) Using pea protein and carrageenan as the aqueous phase and vegetable oil as the oil phase, an emulsion gel was obtained by high-speed shearing using a shearing machine, which served as the core layer; The aqueous phase contains 5-10% pea protein and 0.5-1.5% carrageenan by mass. The volume ratio of the aqueous phase to the oil phase is 1:1; The oil phase also includes functional active substances; the functional active substances include one or more of curcumin, lycopene, and β-carotene. (3) A composite gel was obtained by simultaneously depositing the shell hydrogel phase and the core material through coaxial 3D printing; The parameters for the coaxial 3D printing are as follows: the coaxial 3D printing needle is a 14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm; the moving speed of the 3D printer needle is 6~8 mm / s; and the pushing speed of the peristaltic pump is 1~2 mL / min. (4) Gel the composite gel obtained in step (3) to obtain an easy-to-swallow pea protein-based composite gel; The gelation is carried out by heating and cooling and / or immersion in an ionic solution.

2. The preparation method according to claim 1, characterized in that, When the polysaccharide in step (1) is corn starch, the mass fraction of corn starch in the hydrogel phase is 1%~10%.

3. The preparation method according to claim 1, characterized in that, When the polysaccharide in step (1) is carrageenan, the mass fraction of carrageenan in the hydrogel phase is 0.1%~1%.

4. The preparation method according to claim 1, characterized in that, When the polysaccharide in step (1) is sodium alginate, the mass fraction of sodium alginate in the hydrogel phase is 0.5%~1%.

5. The preparation method according to claim 1, characterized in that, The specific preparation of the hydrogel phase in step (1) is to prepare a polysaccharide dispersion, and then add pea protein to the polysaccharide dispersion and mix evenly.

6. The preparation method according to claim 1, characterized in that, The vegetable oil mentioned in step (2) includes any one or more of soybean oil, rapeseed oil, and corn oil.

7. The preparation method according to claim 1, characterized in that, In step (2), the stirring speed of the shearing machine is 9000~12000 rpm, and the time is 1~3 min.

8. The preparation method according to claim 1, characterized in that, The oil phase in step (2) includes curcumin, and the concentration of curcumin is 2 mg / mL to 4 mg / mL.

9. The preparation method according to claim 1, characterized in that, The heating and cooling conditions are as follows: heating temperature is 80℃~95℃, time is 10 min~15 min, and cooling temperature is 2℃~10℃.

10. The preparation method according to claim 1, characterized in that, The ionic solution is a CaCl2 solution.

11. The preparation method according to claim 10, characterized in that, The mass fraction of the CaCl2 solution is 1% to 2%.

12. The easily swallowable pea protein-based composite gel prepared by the preparation method according to any one of claims 1 to 11.

13. The application of the easily swallowable pea protein-based composite gel according to claim 12 in 3D printed products.

14. A method for improving the stability and activity of functional active factors, characterized in that, The method includes the following steps: (1) Mix pea protein and polysaccharide evenly to form the shell hydrogel phase; The polysaccharide includes one or more of corn starch, carrageenan, and sodium alginate; The mass fraction of pea protein in the hydrogel phase is 20%~25%; The mass fraction of polysaccharides in the hydrogel phase is 0.1%~10%; (2) Using pea protein and carrageenan as the aqueous phase and vegetable oil containing functional active factors as the oil phase, an emulsion gel was obtained by high-speed shearing using a shearing machine, which served as the core layer. The aqueous phase contains 5-10% pea protein and 0.5-1.5% carrageenan by mass. The volume ratio of the aqueous phase to the oil phase is 1:1; The functional active factors include one or more of curcumin, lycopene, and β-carotene; (3) A composite gel was obtained by simultaneously depositing the shell hydrogel phase and the core material through coaxial 3D printing; The parameters for the coaxial 3D printing are as follows: the coaxial 3D printing needle is a 14 G+20 G model, the outer diameter of the 14 G needle is 2.1 mm and the inner diameter is 1.6 mm; the outer diameter of the 20 G needle is 0.9 mm and the inner diameter is 0.6 mm; the moving speed of the 3D printer needle is 6~8 mm / s; and the pushing speed of the peristaltic pump is 1~2 mL / min. (4) Gel the composite gel obtained in step (3) to obtain an easy-to-swallow pea protein-based composite gel; The gelation is carried out by heating and cooling and / or immersion in an ionic solution.

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