CP-GDL synergistic induced modified WalPI-SA emulsion gel as well as preparation method and application thereof
By using low-temperature plasma treatment and synergistic induction of additives to form WalPI-SA emulsion gel, the problem of insufficient precision and stability of emulsion gel in 3D printed food was solved, achieving high-performance 3D printing results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHWEST FORESTRY UNIVERSITY
- Filing Date
- 2026-03-31
- Publication Date
- 2026-05-12
AI Technical Summary
Existing emulsion gels suffer from low printing accuracy and poor structural stability in 3D printed food, while traditional bio-inks offer limited performance improvements.
WalPI-SA solution was modified by low-temperature plasma treatment, and gluconolactone (GDL) and octenyl succinate sucrose ester were added as adjuvants to synergistically induce the formation of WalPI-SA emulsion gel, resulting in a denser spatial network structure.
It improves the stability of emulsion gels and the accuracy of 3D printing, resulting in printed models with clear structures and distinct edges. It solves the bottleneck of traditional bio-inks in 3D printing and provides a development strategy for high-performance 3D printed food.
Smart Images
Figure CN122004452A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of food processing technology, specifically to CP-GDL synergistically induced modified WalPI-SA emulsion gel, its preparation method, and its application. Background Technology
[0002] Emulsion gels are semi-solid substances formed by inducing emulsions through acid treatment, heat treatment, or enzyme treatment. They possess both solid and liquid properties, exhibiting superior stability compared to emulsions, and are commonly used for the encapsulation and delivery of active substances, the development of low-fat foods, and 3D food printing. Compared to emulsion gels stabilized by traditional surfactants, emulsion gels stabilized by biomolecules offer advantages such as higher consumer acceptance, lower toxicity, and greater cost-effectiveness.
[0003] Emulsion gels are mainly composed of polysaccharide groups, protein groups, and polysaccharide-protein groups. These biomolecules cross-link through various mechanisms to form a stable three-dimensional network structure, maintaining the stability of the emulsion gel. Previous studies have shown that emulsion gels stabilized by polysaccharide-protein complexes outperform those stabilized by single proteins or polysaccharides.
[0004] Previous studies have shown that acid-induced emulsion gels exhibit significant advantages in storage stability. Researchers used glucono-delta-lactone (GDL) to prepare emulsion gels and found that the gels maintained good stability after 21 days of storage at 25°C. GDL, as an acidifier, can induce cross-linking and aggregation of protein-polysaccharide complex particles by lowering the pH of the emulsion gel, forming a stable spatial structure. Different amounts of GDL added affect the properties of the emulsion gel by influencing the acidification rate and endpoint.
[0005] 3D printing is a novel additive manufacturing technology. Due to its high processing speed, high creativity, and good product quality, it has become a research hotspot and shows great application potential in the food processing field. Utilizing the rheological properties of biomolecules under certain conditions, they can be used as 3D printing bio-inks. Common bio-inks include starch colloids, protein colloids, and emulsion gels. The relationship between the rheological properties and strength of bio-inks and the accuracy and stability of 3D printed products still warrants further investigation.
[0006] In our previous research (Gao Baoyu, Lu Yanling, Deng Yanmei, et al. Effects of low-temperature plasma treatment on the structure and properties of sodium alginate-walnut protein isolate [J]. Food and Fermentation Industries, 2025, 51(20): 215-223. DOI:10.13995 / j.cnki.11-1802 / ts.042097.), we found that CP treatment can effectively improve the solubility, thermal stability and grafting degree of WalPI-SA composite particles. Therefore, this study uses CP-treated modified WalPI-SA composite particles as raw materials to explore the effects of additives on the structure, properties and 3D printing performance of WalPI-SA emulsion gel, in order to provide scientific basis and theoretical guidance for the development and utilization of emulsion gels. Summary of the Invention
[0007] The purpose of this invention is to solve the above-mentioned technical problems by providing CP-GDL synergistically induced modified WalPI-SA emulsion gel, its preparation method and application.
[0008] The present invention achieves the above objectives through the following technical solutions: As a first aspect of the present invention, a CP-GDL synergistically induced modified WalPI-SA emulsion gel is provided. The emulsion gel is prepared by using walnut protein isolate-sodium alginate solution WalPI-SA as raw material, which is treated with low-temperature plasma, induced by additives, and then added to the oil phase. The additives include at least one of gluconolactone (GDL) and sucrose octenyl succinate.
[0009] As a further optimization of the present invention, the adjuvant is a mixture of gluconolactone GDL and sucrose octenyl succinate, with a ratio of 1-4:1-4.
[0010] As a further optimization of the present invention, the amount of the adjuvant is 10-20% of the amount of walnut protein isolate.
[0011] As a further optimization of the present invention, the oil phase is any one of soybean oil, corn oil or peanut oil.
[0012] As a second aspect of the present invention, a method for preparing CP-GDL synergistically induced modified WalPI-SA emulsion gel as described in any one of the above claims is also provided, comprising the following steps: (1) WalPI isolated protein and sodium alginate SA were co-dissolved in phosphate buffer solution, and hydrated overnight by magnetic stirring to obtain WalPI-SA solution; (2) The WalPI-SA solution obtained in step (1) is subjected to low-temperature plasma treatment after being magnetically stirred; (3) Add the additive to the WalPI-SA solution obtained in step (2), stir magnetically to obtain a mixture, add the oil phase to the mixture, and homogenize to obtain the WalPI-SA emulsion gel.
[0013] As a further optimization of the present invention, in step (1), the ratio of walnut protein isolate (WalPI) to sodium alginate (SA) is 5g:2g.
[0014] As a further optimization of the present invention, in step (1), the concentration of the phosphate buffer solution is 0.1 mol / L and the pH is 7.0.
[0015] As a further optimization of the present invention, in step (2), the processing voltage of the low-temperature plasma treatment is 80 V, the processing current is 1.0±0.2A, and the processing time is 60s.
[0016] As a further optimization of the present invention, in step (3), the ratio of the volume of WalPI-SA solution to the oil phase is 9 mL: 21 mL.
[0017] As a third aspect of the present invention, the application of CP-GDL synergistically induced modified WalPI-SA emulsion gel as described in any of the above claims in the preparation of 3D printed food is also provided.
[0018] The beneficial effects of this invention are as follows: (1) This invention uses CP-pretreated WalPI-SA solution as raw material and successfully prepares high-performance WalPI-SA emulsion gel through auxiliary agent induction. According to the study, the auxiliary agent selected is a combination of gluconolactone GDL and octenyl succinate sucrose ester, which can synergistically promote cross-linking between solid particles, increase steric hindrance, and form a denser WalpI-SA spatial network structure. The two work together to stabilize and improve the structure and properties of WalpI-SA emulsion gel, thereby effectively improving its stability.
[0019] (2) The preparation method of the emulsion gel provided by the present invention is simple and easy to implement. When the prepared WalPI-SA emulsion gel is used for 3D printing, the printed model has high precision, clear structure and obvious edges, which solves the core bottleneck of low printing precision and poor structural stability of traditional bio-ink, and provides a new strategy for the development of high-performance 3D printed food. Attached Figure Description
[0020] Figure 1 Comparison of 3D printability test results of CP-WalPI-SA emulsion gel and Un-CP-WalPI-SA emulsion gel provided by the present invention; Figure 2This invention provides a comparison of the 3D printable test results of emulsion gels with different amounts of additives. Detailed Implementation
[0021] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0022] Walnut protein isolate (WalPI) was obtained by alkaline solubilization and acid precipitation, referring to the paper by Gao Baoyu, Lu Yanling, Deng Yanmei, et al. Effects of low-temperature plasma treatment on the structure and properties of sodium alginate-walnut protein isolate [J]. Food and Fermentation Industries, 2025, 51(20): 215-223. DOI:10.13995 / j.cnki.11-1802 / ts.042097.
[0023] Sodium alginate (SA), gluconolactone (GDL), and octenyl succinate sucrose ester were all of analytical grade. The oil phase can be soybean oil, corn oil, or peanut oil; soybean oil was chosen in this study.
[0024] Unless otherwise specified, all reagents and materials used below are commercially available products. Unless otherwise specified, all methods used below are conventional methods known to those skilled in the art.
[0025] 1. Preparation of WalPI-SA emulsion gel 1.1 Preparation of CP-modified WalPI-SA solution Based on the team's previous research, the preparation method of CP-modified WalPI-SA solution is as follows: 5 g WalPI and 2 g SA are co-dissolved in 1000 mL (0.1 mol / L, pH=7.0) PBS, magnetically stirred at 200 r / min for 3 h at room temperature, and hydrated overnight to obtain WalPI-SA solution; The overnight hydrated WalPI-SA solution was taken and magnetically stirred at 200 r / min for 30 min. 100 mL of this solution was then placed in a CP reactor (Nanjing Suman Plasma Technology CTP-2000KP-10KHz) for CP treatment. The CP treatment time was controlled at 60 s, the current at 1.0 ± 0.2 A, and the voltage at 80 V. After treatment, the sample was ready for subsequent use.
[0026] 1.2 Preparation of WalPI-SA emulsion gel without added additives Take 9 mL of CP-treated WalPI-SA solution and mix it by magnetic stirring at 200 r / min for 10 min to obtain a mixture. Based on the team's previous research, the optimal amount of additive is 10% of the amount of WalPI. Add 21 mL of soybean oil to the mixture and homogenize at high speed (FJ200-SH type, Shanghai Huxi Industrial Co., Ltd.) for 5 min to obtain WalPI-SA emulsion gel without additive (denoted as CP-WalPI-SA).
[0027] To compare the effect of CP modification on the 3D printability of WalPI-SA emulsion gel, WalPI-SA emulsion gel obtained without CP modification was used as the control group (Un-CP-WalPI-SA).
[0028] 1.3 3D Printable Testing Two emulsion gel samples, CP-WalPI-SA and Un-CP-WalPI-SA, were filled into a plastic syringe and printed at room temperature through a 0.8 mm diameter nozzle. The parameters were set as follows: travel speed 25 mm / s, layer height 1 mm, and room temperature 25°C. The results are as follows... Figure 1 As shown.
[0029] from Figure 1 As can be seen, the Un-CP-WalPI-SA emulsion gel printing model has the worst accuracy, structural collapse (deformation >20%), and poor molding. Compared with the Un-CP-WalPI-SA emulsion gel without CP treatment, the CP-WalpI-SA emulsion gel printing model has improved accuracy, increased structural clarity, and better printed model shape.
[0030] Preparation of WalPI-SA emulsion gel with added additives Based on the 3D printability test results of the two emulsion gel samples, CP-WalPI-SA and Un-CP-WalPI-SA, in Section 1.3, 9 mL of CP-treated WalPI-SA solution was mixed with different components of additives (as shown in Table 1), and stirred magnetically at 200 r / min for 10 min to obtain a mixture. According to the team's previous research, the optimal amount of additive is 10% of the WalPI dosage. 21 mL of soybean oil was added to the mixture, and the mixture was homogenized at high speed (FJ200-SH type, Shanghai Huxi Industrial Co., Ltd.) for 5 min to obtain the WalPI-SA emulsion gel with additives.
[0031] Table 1. Additive systems with different components The corresponding emulsion-gel samples were designated as CP-WalPI-SA-a, CP-WalPI-SA-b, CP-WalPI-SA-c, CP-WalPI-SA-d, CP-WalPI-SA-e, and CP-WalPI-SA-f, respectively.
[0032] In addition, WalPI-SA emulsion gel (CP-WalPI-SA) without added additives was used as a control.
[0033] 3. Performance characterization of WalPI-SA emulsion gel 3.1 Water-holding capacity test Water-holding capacity (WHC) is an important indicator for determining the stability of emulsion gels; a higher WHC indicates a stronger water-locking ability. The method for determining water-holding capacity is as follows: Weigh 8 g of the emulsion gel sample into a centrifuge tube, centrifuge at 8500 r / min for 10 min, and remove the water collected. Weigh and record the gel mass (H. Li, et al., 2022). The formula for calculating water-holding capacity is shown below: In the formula: M0 is the mass of the gel before centrifugation, g, and M1 is the mass of the gel after centrifugation, g.
[0034] The results are shown in Table 2.
[0035] Table 2 Results of water retention test Table 2 shows that the water holding capacity of the untreated emulsion gel CP-WalPI-SA was 63.96%. The water holding capacity of the emulsion gels improved after the addition of additives. GDL, as an acidifier, induced emulsion gel formation, resulting in more WalpI-SA particles undergoing orderly cross-linking and participating in the formation of the emulsion gel, thus improving gel integrity. Furthermore, the increased disulfide bond content during acid-induced emulsion gelation enhanced the WHC of the emulsion gel, increasing the water holding capacity of CP-WalPI-SA-b to 86.54%. Furthermore, when octenyl sucrose ester was used in combination with GDL, the water-holding capacity of the emulsion gel increased and then decreased as the proportion of octenyl sucrose ester in the adjuvant increased. When the mass ratio of GDL to octenyl sucrose ester was 3:2, the water-holding capacity of the emulsion gel reached a maximum of 88.67%.
[0036] 3.2 Determination of interfacial protein adsorption rate The stability of emulsion gels depends on the interfacial tension between the oil and aqueous phases (the work done to increase the size of the interface between two immiscible phases). When the oil and aqueous phases are in direct contact, the interfacial tension is very high, which is detrimental to system stability. However, by utilizing the adsorption of amphiphilic molecules at the oil-water interface, the interfacial tension can be effectively reduced, thus improving the stability of the system. Therefore, the higher the adsorption rate of interfacial proteins, the lower the interfacial tension, and the better the dispersibility of the emulsion gel droplets. The determination method was as follows: the emulsion gel sample was centrifuged (1000 rpm, 30 min), and the aqueous phase was filtered through a 0.22 μm filter membrane after centrifugation. The protein content in different phases before and after centrifugation was determined by the Coomassie Brilliant Blue method. The formula for calculating the interfacial protein adsorption rate is as follows (Dai, et al., 2019): ; In the formula: A0 is the protein content in the original emulsion gel (g / L); A1 is the protein content in the aqueous phase after centrifugation (g / L).
[0037] The results are shown in Table 3.
[0038] Table 3 Results of interfacial protein adsorption rate determination As can be seen from the table, the addition of additives promotes cross-linking between solid particles, increases steric hindrance, and enables the solid particles at the interface to form a more stable interfacial film. Furthermore, as the proportion of octenyl sucrose ester in the additives increases, the interfacial protein adsorption rate of the emulsion gel shows a trend of first increasing and then decreasing. When the mass ratio of GDL to octenyl sucrose ester is 3:2, the water-holding capacity of the emulsion gel reaches its maximum value of 68.51%.
[0039] 3.3 Determination of textural properties Texture properties are categorized into hardness, cohesiveness, chewiness, and elasticity. Hardness reflects the degree of aggregation of the emulsion gel network and the density of cross-linked protein molecules. Cohesiveness characterizes the strength of the internal binding force of the emulsion gel; a higher value indicates a denser internal structure. Chewiness represents the energy required to chew the emulsion gel. Elasticity is the ability of the emulsion gel to recover its shape after being compressed by external force.
[0040] The determination method was as follows: The sample was made into a uniform cylinder (1 cm in diameter and 2 cm in height) and placed on the testing platform of the texture analyzer (TMS-PRO texture analyzer, FTC, USA). A P / 0.5 R type probe (12 mm in diameter) was used for testing. The full texture test program was entered with the following parameter settings: trigger force value of 0.049 N, pressing distance of 5 mm, pressing speed of 1 mm / s, and interval between two cycles of 5 s (Yu, Ren, Zhao, Cui, & Liu, 2020).
[0041] The results are shown in Table 4.
[0042] Table 4 Results of Texture Properties Measurement As shown in Table 5, compared with the emulsion gel CP-WalPI-SA without additives, the addition of GDL increased the degree of cross-linking and aggregation of WalpI-SA composite particles under low pH conditions, increased the stability of the gel network structure, enhanced the ability to retain water, and promoted the increase of emulsion gel hardness. Further addition of octenyl sucrose ester to replace part of the GDL content improved the hardness, elasticity, chewiness, and cohesiveness of the emulsion gel. However, when the amount of octenyl sucrose ester is too large, it will weaken the intermolecular forces that maintain the stability of the emulsion gel structure, thus affecting the taste of the emulsion gel.
[0043] 3.4 Static Scan Test Set the shear rate to 0.01~100 s. -1 Thirty sampling points were used to analyze the changes in apparent viscosity and stress with shear rate. The Herschel-Bulkley model was used to fit the shear stress-shear rate diagram; the specific equations of the model are as follows: In the formula: σ is the shear stress; σ0 is the yield stress; γ is the shear rate; n is the fluid index; k is the viscosity coefficient.
[0044] The results are shown in Table 5.
[0045] Table 5 Fitting parameters of the Herschel-Bulkley model for emulsion gels As shown in Table 5, the model coefficients R0 2 The range of 0.967-0.991 indicates that the model fits the rheological curve well and can accurately describe the rheological behavior of the gel. In the table, n (fluid index) is less than 1, indicating that the emulsion gel exhibits shear thinning within this shear range. k is the consistency coefficient; a larger value indicates a higher viscosity of the emulsion gel. The yield stress is the maximum stress required for the emulsion gel to undergo initial shearing; a higher value indicates a greater shear force and thus a more stable structure. When using emulsion gels in 3D printing, both extrudability and shape integrity can be satisfied. As shown in the table, the additives, a combination of GDL and sucrose octenyl succinate, synergistically enhance the spatial structure of the emulsion gel, increase its yield stress, and reduce its pseudoplastic behavior. This combination effectively promotes the structural stability of the emulsion gel, laying the foundation for its application in 3D printing.
[0046] 3.5 3D Printable Testing Based on the above series of performance characterization studies, it is evident that the specific selection of additives has a significant impact on the structural stability of the emulsion gel. The CP-WalPI-SA-c emulsion gel sample, exhibiting excellent overall performance, was filled into a plastic syringe and printed at room temperature through a nozzle with a diameter of 0.8 mm. The parameters were set as follows: movement speed of 25 mm / s, layer height of 1 mm, and room temperature of 25 °C.
[0047] In addition, the amount of additives added to the CP-WalPI-SA-c emulsion gel sample was adjusted. The amount of additives (gluconolactone: sucrose octenyl succinate = 3:2) was adjusted to 20% of the WalPI amount, and the emulsion gel sample was prepared according to the method shown in Section 2. This sample was then filled into a plastic syringe and printed at room temperature through a nozzle with a diameter of 0.8 mm. The parameters were set as follows: movement speed of 25 mm / s, layer height of 1 mm, and room temperature of 25°C.
[0048] The results are as follows Figure 2 As shown, the CP-WalPI-SA-c emulsion gel sample can be successfully printed through the nozzle, exhibiting a basic shape. The printed model has high precision, clear structure, and distinct edges. However, after increasing the amount of additives, the printed latex gel sample has lower structural clarity and edge distinctness than the CP-WalPI-SA-c emulsion gel sample. This may be attributed to excessive additives, which leads to excessively fast coagulation of the aqueous phase of the emulsion gel, insufficient bridging between the solid particles of the emulsion gel, and weakened intermolecular forces, thus hindering the improvement of 3D printing results.
[0049] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.
Claims
1. A CP-GDL synergistically induced modified WalPI-SA emulsion gel, characterized in that: The emulsion gel is prepared by using walnut protein isolate-sodium alginate solution WalPI-SA as raw material, which is treated with low-temperature plasma, induced by additives, and then added to the oil phase. The additives include at least one of gluconolactone GDL and octenyl succinate sucrose ester.
2. The CP-GDL synergistically induced modified WalPI-SA emulsion gel according to claim 1, characterized in that, The adjuvant is a mixture of gluconolactone GDL and octenyl succinate sucrose ester, with a ratio of 1-4:1-4.
3. The CP-GDL synergistically induced modified WalPI-SA emulsion gel according to claim 1, characterized in that, The amount of the adjuvant is 10-20% of the amount of walnut protein isolate.
4. The CP-GDL synergistically induced modified WalPI-SA emulsion gel according to claim 1, characterized in that, The oil phase is any one of soybean oil, corn oil, or peanut oil.
5. A method for preparing CP-GDL synergistically induced modified WalPI-SA emulsion gel as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) WalPI isolated protein and sodium alginate SA were co-dissolved in phosphate buffer solution, and hydrated overnight by magnetic stirring to obtain WalPI-SA solution; (2) The WalPI-SA solution obtained in step (1) is subjected to low-temperature plasma treatment after being magnetically stirred; (3) Add the additive to the WalPI-SA solution obtained in step (2), stir magnetically to obtain a mixture, add the oil phase to the mixture, and homogenize to obtain the WalPI-SA emulsion gel.
6. The preparation method and application of the emulsion gel based on the modified WalPI-PA complex according to claim 5, characterized in that, In step (1), the ratio of WalPI (walnut protein isolate) to sodium alginate (SA) is 5 g: 2 g.
7. The method for preparing CP-GDL synergistically induced modified WalPI-SA emulsion gel according to claim 5, characterized in that, In step (1), the concentration of the phosphate buffer solution is 0.1 mol / L and the pH is 7.
0.
8. The CP-GDL synergistically induced modified WalPI-SA emulsion gel according to claim 5, characterized in that, In step (2), the processing voltage of the low-temperature plasma treatment is 80 V, the processing current is 1.0 ± 0.2 A, and the processing time is 60 s.
9. The method for preparing CP-GDL synergistically induced modified WalPI-SA emulsion gel according to claim 5, characterized in that, In step (3), the ratio of the volume of WalPI-SA solution to the oil phase is 9 mL: 21 mL.
10. The application of CP-GDL synergistically induced modified WalPI-SA emulsion gel as described in any one of claims 1-4 in the preparation of 3D printed food.