Method for improving starch 3D printing characteristics and product retrogradation performance

Abstract

The invention discloses a method for improving starch 3D printing characteristics and product retrogradation performance, and belongs to the crossing field of food engineering, 3D printing materials and food processing technologies. Dispersing high-amylose corn starch in water to prepare a starch suspension, and performing gelatinization treatment; adding an edible rose polyphenol extract into the gelatinized starch solution, uniformly stirring, and carrying out multi-mode ultrasonic treatment on the starch and rose polyphenol mixture to obtain a rose polyphenol-high amylose corn starch compound; adding hydrophilic colloid into the compound, uniformly stirring, and cooling to room temperature to form modified starch gel; and 3D printing is conducted on the starch gel, and a 3D printing product is obtained. The problems that starch is poor in 3D printing performance and digestion performance and printed products are fast in retrogradation are effectively solved, a core material solution is provided for developing personalized 3D printing food which is high in performance, nutritional, healthy and long in shelf life, and a new technical approach is provided for functional 3D printing food.

Description

Technical Field

[0001] This invention relates to the field of food 3D printing technology, specifically to a method for improving the 3D printing characteristics of starch and the product's retrogradation properties, belonging to the interdisciplinary field of food engineering, 3D printing materials, and food processing technology. Background Technology

[0002] 1. Core technological challenges and industry needs

[0003] Food 3D printing technology, as an emerging digital manufacturing technology, has shown great application potential in personalized nutrition customization, medical nutrition, and functional foods. This technology places strict requirements on the key rheological properties of printing materials (such as flow stress, yield stress, and storage modulus), and the materials must exhibit significant shear-thinning behavior to meet the needs of precise extrusion and molding. Starch, due to its low cost, abundant sources, and ease of modification, is considered an ideal basic material for 3D printing. However, the direct application of natural starch in 3D printing faces the following core technical challenges that urgently need to be addressed: ① poor printability (excessively high viscosity of natural starch gelatinized gel); ② insufficient nutritional health benefits (high content of rapidly digestible starch); ③ low storage stability (retrogradation problem). Therefore, there is an urgent need to construct a starch-based composite material system that possesses excellent 3D printing adaptability while maintaining high nutritional value and good storage stability to solve the problems existing in current starch-based 3D printing materials.

[0004] 2. Existing modification technologies and their limitations

[0005] To address the aforementioned issues, existing starch modification technologies suffer from the following limitations: First, each technical route has significant drawbacks. While chemical modification methods can improve specific properties, they pose safety risks due to chemical reagent residues, contradicting the development trends of clean labeling and green food, resulting in low consumer acceptance. Enzymatic modification yields better results, but enzyme preparations are expensive (typically 3-5 times the cost of chemical reagents), significantly increasing production costs and hindering its large-scale industrial application. Existing physical modification methods (such as traditional ultrasound and heat treatment) are relatively safe, but they fall short in terms of synergistic performance enhancement. Second, key technological bottlenecks have not yet been overcome. For example, in existing starch-polyphenol composite technologies, the polyphenol binding rate is generally low, and the binding efficiency is unstable. 3D printing performance optimization is limited; the improvement effect of a single hydrophilic colloid on starch printing performance is limited, and there is a lack of theoretical guidance on the synergistic mechanism of compound colloids tailored to the rheological requirements of 3D printing. Furthermore, the contradiction of performance synergy optimization is difficult to resolve. Existing technical solutions often sacrifice one aspect for another, making it difficult to simultaneously meet multiple performance requirements. For example, improving printing flowability often accompanies an increase in the proportion of rapidly digestible starch; enhancing resistance to digestion (such as forming resistant starch) often accelerates the retrogradation process; while pursuing high performance leads to a significant increase in cost, far exceeding the cost increase threshold acceptable for industrialization. Therefore, there is an urgent need to develop a new starch modification strategy that is efficient, green, low-cost, and can synergistically optimize the ternary properties.

[0006] 3. The technological innovation value of this invention

[0007] Based on the above analysis of the current state of technology, this invention addresses the systemic defects of existing technologies by proposing a comprehensive and innovative technical solution that combines multi-mode ultrasound-assisted modification of high amylose corn starch with rose polyphenols, along with hydrophilic colloid regulation of 3D printing and regeneration properties.

[0008] The core innovative value of this invention lies in its successful resolution of the aforementioned contradictions, and its technical breakthrough is specifically reflected in:

[0009] (1) Multi-mode ultrasound-assisted modification of rose polyphenols: This method overcomes the limitations of single physical or chemical modification by utilizing the synergistic physical effects (cavitation, mechanical, and thermal effects) generated by multi-mode ultrasound to efficiently promote the interaction and complexation between rose polyphenols and starch molecules, significantly improving the polyphenol binding rate and the stability of the complex. This process requires no chemical reagents and meets clean label requirements.

[0010] (2) Filling the gap in the application of rose polyphenol extract and optimizing the composite process: Rose polyphenol extract was systematically developed and applied to the green process of starch modification, providing a technical basis for the industrial preparation of efficient and stable composites.

[0011] (3) Constructing a synergistic regulation system of hydrophilic colloids: By innovatively selecting and compounding specific hydrophilic colloids, based on their significant influence on starch gelatinization, rheology and retrogradation processes, a synergistic mechanism was established to regulate the rheological properties of 3D printing (achieving excellent shear thinning and extrusion molding, with printing accuracy ≥95%) and inhibit starch retrogradation (significantly reducing the problem of increased hardness and moisture loss during storage), effectively solving the contradiction between printability and long-term storage stability.

[0012] (4) Achieving comprehensive optimization of performance, cost and safety: This solution uses efficient physical modification combined with natural ingredients (rose polyphenols, hydrocolloids) to significantly improve comprehensive performance (printability, digestibility, and resistance to retrogradation) while strictly controlling the cost increase within an acceptable range for industrialization and completely avoiding the risk of chemical residues, which is in line with the industrial trend of green sustainable development and clean labeling.

[0013] The significance of this invention lies in its ability to effectively solve the processing difficulties encountered by high amylose-based starch in 3D printing applications through the synergistic effect of multi-mode ultrasound and hydrophilic colloids. It not only overcomes the key technical bottlenecks faced by starch-based 3D printing materials, providing a core material solution for developing high-performance, nutritious, and long-shelf-life personalized 3D printed foods, but also establishes a technological high ground with significant competitive advantages in the rapidly growing 3D food printing market, powerfully promoting the industrialization process of this technology. Summary of the Invention

[0014] The purpose of this invention is to construct a starch-based composite material system that possesses both excellent 3D printing suitability and maintains high nutritional value and good storage stability, thereby addressing the problems existing in current starch-based 3D printing materials. By treating high-amylose corn starch with multi-mode ultrasound in conjunction with rose polyphenols, and combining this with the addition of hydrophilic colloids, the 3D printing characteristics, digestibility, and reversion properties of starch-based materials are effectively improved.

[0015] To achieve the above objectives, the present invention adopts the following technical solution:

[0016] A method for improving the properties of starch in 3D printing and the reversion performance of products, comprising the following steps:

[0017] (1) Disperse high amylose corn starch in water to prepare a starch suspension, and then heat the starch suspension to gelatinize it.

[0018] (2) Add edible rose polyphenol extract to the gelatinized starch solution, stir evenly, and then subject the starch and rose polyphenol mixture to multi-mode ultrasonic treatment to obtain rose polyphenol-high amylose corn starch complex.

[0019] (3) Add hydrophilic colloid to the rose polyphenol-high amylose corn starch complex, stir evenly and cool to room temperature to form modified starch gel;

[0020] (4) 3D printing of modified starch gel to prepare 3D printed products.

[0021] In step (1), the mass ratio of high amylose corn starch to deionized water is 1:9, the heating temperature is 95℃, and the heating time is 30 minutes.

[0022] In step (2), the rose polyphenol extract was extracted for 30 min under synchronous ultrasonic conditions with an ultrasonic power of 300 W and a frequency of 20+28 kHz. After ultrasonication, it was centrifuged at 11000 g for 10 min and then passed through an AB-8 macroporous resin column at a flow rate of 1.0 mL / min. It was eluted with 70% ethanol at a flow rate of 1.0 mL / min. After vacuum freeze-drying, the extract was pulverized and passed through an 80-mesh standard sieve.

[0023] In step (2), the amount of rose extract added is 8% based on dry starch weight, and the cooling temperature is 70°C. The parameters of the multi-mode ultrasonic treatment are: power of 250W, time of 15 minutes, and ultrasonic frequency of three-frequency sequential mode. Sequential mode means that in the three-frequency mode, the three frequencies of 20kHz, 40kHz and 60kHz are switched sequentially every 5 seconds.

[0024] In step (3), the hydrophilic colloid is selected from xanthan gum, guar gum, carrageenan or gelatin. The amount of xanthan gum added is 2%, the amount of guar gum added is 1.5%, the amount of carrageenan added is 1.5%, and the amount of gelatin added is 1.5%, all based on the dry weight of starch.

[0025] In step (3), the hydrophilic colloid is homogenized at 9000 rpm for 2 hours, heated to 70°C in a water bath, and then added to the rose polyphenol-high amylose corn starch complex.

[0026] In step (3), the starch gel is stored at 4°C for 12 hours.

[0027] In step (4), the 3D printing parameters are: printing speed 20mm / s, number of layers 10, nozzle diameter 1.5mm, and number of revolutions 2.

[0028] The obtained 3D printed products, when stored at 4℃ or -20℃, showed that the retrogradation inhibition rate remained above 60% after 14 days of storage at -20℃, and the resistant starch content increased by more than 20%.

[0029] The beneficial effects of this invention are:

[0030] (1) This invention applies multimode ultrasound to the preparation of starch-polyphenol complex. Compared with traditional starch, multimode ultrasound provides a more uniform sound field distribution, stronger cavitation effect and mechanical effect, which can more effectively destroy the starch structure and promote the combination of rose polyphenols and starch to form a stable complex. After modification, the content of resistant starch increased from 33.61% to 57.20%, which significantly improved the digestibility of starch.

[0031] (2) This invention systematically studied different types and suitable concentrations of hydrophilic colloids. After adding hydrophilic colloids, the extrusion effect of the complex was improved by reducing its viscosity, while the mechanical strength of the gel was enhanced, and the self-supporting ability of the printed product was improved, so that the 3D printing accuracy reached 98.94%-99.21%. Unlike traditional methods, the modified starch 3D printing products prepared by this invention have the advantages of uniform lines, stable shape, and good interlayer bonding.

[0032] (3) The hydrophilic colloid added in this invention can significantly inhibit the retrogradation of 3D printed products during storage. By interfering with starch molecule rearrangement and reducing starch chain migration, the retrogradation inhibition rate still exceeds 60% after 14 days of storage at -20℃, which is much higher than the control group without added hydrophilic colloid. At the same time, the hydrophilic colloid increases the resistant starch content of the printed products, giving the products good glycemic regulation function.

[0033] (4) The multi-mode ultrasound technology used in this invention is a green and safe food processing method. The selected hydrophilic colloids are all food-grade safe additives. The entire process does not require the addition of chemical reagents, meets food safety requirements, and has good application prospects. This method can not only be used for 3D printing of starch-based foods, but also provides new ideas for the modification and functionalization of other biomaterials. Attached Figure Description

[0034] Figure 1 The following is a schematic diagram of the process flow of the method of the present invention, wherein: (1) is a starch gelatinization step, which includes dispersing high amylose corn starch in deionized water to prepare a suspension and heating it at 95°C for 30 minutes; (2) is an ultrasonic modification step, which includes adding rose polyphenol extract to the gelatinized starch solution and performing multi-mode ultrasonic treatment to form a rose polyphenol-high amylose corn starch complex; (3) is a colloid modification step, which includes adding hydrophilic colloid to the complex, stirring it evenly and cooling it to room temperature to form a modified starch gel; (4) is a 3D printing step, which involves 3D printing the modified starch gel to prepare the final product.

[0035] Figure 2The diagram shows the 3D printed products prepared according to the present invention. Using the four hydrophilic colloidal modified starch gels prepared in Example 1 as raw materials, complex geometric patterns such as butterflies, letters, flowers, horses, game controllers, and pyramids were successfully printed. The printed products have the following characteristics: the one-dimensional structure has continuous and smooth lines without any breakage; the two-dimensional structure has a regular shape, clear surface texture, and smooth corners; the three-dimensional structure has excellent self-support, no collapse, and stable structure. Detailed Implementation

[0036] To better understand the present invention, specific embodiments are described in detail below. Those skilled in the art should understand that these embodiments are for illustrative purposes only and should not be considered as limiting the invention. The scope of protection of the present invention is determined by the appended claims.

[0037] Example 1: Preparation of Xanthan Gum-Modified Starch 3D Printing Gel by Three-Frequency Ultrasound Synergistic

[0038] Fresh edible rose petals were extracted for 30 minutes using simultaneous ultrasonication at a power of 300W and a frequency of 20 ± 28 kHz. After ultrasonication, the extract was centrifuged at 11000g for 10 minutes, then passed through an AB-8 macroporous resin column at a flow rate of 1.0 mL / min. Elution was performed with 70% ethanol at a flow rate of 1.0 mL / min. The extract was then freeze-dried under vacuum, pulverized, and passed through an 80-mesh standard sieve to obtain rose polyphenol extract powder for later use.

[0039] A certain amount of high amylose corn starch was dissolved in water and stirred thoroughly to obtain a starch solution (starch concentration of 10%). This solution was then gelatinized by heating in a water bath at 95℃ for 30 minutes. After cooling to 70℃, 8% (dry weight of starch) of rose polyphenol extract was added, and the mixture was stirred until homogeneous. The solution was then subjected to ultrasonic treatment: time 15 min, power 250 W, frequency 20 / 40 / 60 kHz in a three-frequency sequential mode. Xanthan gum was homogenized at 9000 rpm for 2 hours and then heated in a water bath to 70℃. After ultrasonication, a 2% xanthan gum solution (based on dry weight of starch) was added to the gelatinized starch, stirred until homogeneous, cooled to room temperature, and then placed at 4℃ for 12 hours to form a starch gel. The starch gel was then printed using a 3D printer with the following parameters: printing speed 20 mm / s, 10 layers, diameter 15 mm, and 2 revolutions.

[0040] The composite material prepared in this embodiment achieved a printing accuracy of 99.11%, with significantly improved printing effect, continuous and smooth lines without broken filaments; compared with Comparative Example 1, the resistant starch content increased by 24.18%; the 14-day retrogradation inhibition rate reached 73.11%, and the storage stability was significantly enhanced.

[0041] Example 2: Preparation of 3D Printed Gel of Guar Gum-Modified Starch by Three-Frequency Ultrasound Synergistic

[0042] The preparation process is the same as in Example 1, except that guar gum is used instead of xanthan gum, and the concentration is 1.5% (dry weight of starch).

[0043] In this embodiment, the printing accuracy reached 99.15%, and the printing effect was significantly improved. Compared with Comparative Example 1, the resistant starch content increased by 22.47%; the 14-day retrogradation inhibition rate was 71.95%, and the storage stability was significantly enhanced.

[0044] Example 3: Preparation of 3D Printed Starch Gel by Three-Frequency Ultrasound Synergistic Gelatin Modification

[0045] The preparation process is the same as in Example 1, except that gelatin is used instead of xanthan gum, and the concentration added is 1.5% (dry weight of starch).

[0046] The printing accuracy of this embodiment reached 99.21%, and the molding quality was excellent. Compared with Comparative Example 1, the resistant starch content increased by 20.67%. The 14-day retrogradation inhibition rate was 69.63%, which was slightly lower than other colloids but still significantly better than the control group.

[0047] Example 4: Preparation of 3D Printing Gel for Carrageenan-Modified Starch by Three-Frequency Ultrasound Synergistic

[0048] The preparation process is the same as in Example 1, except that carrageenan is used instead of xanthan gum, and the concentration is 1.5% (dry weight of starch).

[0049] Compared with the comparative example, the printing accuracy of this embodiment reached 98.94%, and the molding stability was good; compared with the comparative example 1, the resistant starch content increased by 21.99%; the 14-day retrogradation inhibition rate was 70.79%, and the long-term storage performance was excellent.

[0050] Example 5: Application of printing complex 3D structures

[0051] Using the xanthan gum-modified gel prepared in Example 1, complex three-dimensional structures were printed and verified, including one-dimensional structures (line patterns), two-dimensional structures (letter and flower patterns), and three-dimensional structures (stereo models). High-precision molding was achieved in all cases, with continuous and smooth lines and stable structures without collapse. Figure 2 ).

[0052] Comparative Example 1: Control group without ultrasound treatment

[0053] The preparation process was the same as in Example 1, but the ultrasonic treatment step was omitted. Rose polyphenols were directly mixed with gelatinized starch, stirred for 30 minutes, and then xanthan gum was added. The prepared product contained only 33.61% resistant starch, resulting in frequent filament breakage during printing and poor molding quality.

[0054] Comparative Example 2: Control group without hydrophilic colloids

[0055] The preparation process followed the ultrasonic treatment described in Example 1, but without the addition of any hydrophilic colloid. The resistant starch content in the prepared product was 57.20%, demonstrating the effectiveness of ultrasonic modification; however, the 14-day retrogradation inhibition rate of the prepared product was only 42.75%, significantly lower than that of the group with added colloid. The material exhibited poor flowability during printing, was prone to collapse, and showed severe retrogradation during storage.

[0056] Table 1. Overall impact of four hydrophilic colloids on 3D printing and functional performance.

[0057]

[0058] Table 1 illustrates that the four hydrophilic colloids of this invention significantly improved the performance of starch-based 3D printing materials. Regarding printability, the printing accuracy of the composites prepared by the four hydrophilic colloid modifications all exceeded 98%, achieving stable molding of high-precision complex structures. In terms of digestibility, the resistant starch content significantly increased from 33.6% to 54.28-57.79%, and the RS content was greatly improved, laying a solid foundation for the development of functional foods. Regarding retrogradation performance, the retrogradation inhibition rate after 14 days of storage increased from 0 to 69.63%-73.11%, demonstrating excellent long-term storage stability. The technical solution exhibits universality, with all four hydrophilic colloids showing significant effects. Xanthan gum exhibited the best overall performance, providing diversified technical options for different application scenarios and cost requirements.

[0059] In summary, this invention provides a method that simultaneously improves the 3D printing characteristics, digestibility, and retrogradation properties of starch-based materials through the synergistic effect of multi-mode ultrasound technology, rose polyphenol modification, and hydrophilic colloid addition. This method solves key technical problems in starch 3D printing and has significant novelty, inventiveness, and practicality, which is of great significance for promoting the development of personalized nutritional foods based on starch 3D printing.

Claims

1. A method for improving the characteristics of starch 3D printing and the product reversion performance, characterized in that... Follow these steps: (1) Disperse high amylose corn starch in water to prepare a starch suspension, and then heat the starch suspension to gelatinize it. (2) Add edible rose polyphenol extract to the gelatinized starch solution, stir evenly, and then subject the starch and rose polyphenol mixture to multi-mode ultrasonic treatment to obtain rose polyphenol-high amylose corn starch complex. (3) Add hydrophilic colloid to the rose polyphenol-high amylose corn starch complex, stir evenly and cool to room temperature to form modified starch gel; (4) 3D printing of modified starch gel to prepare 3D printed products.

2. The method for improving the characteristics of starch 3D printing and the product reversion performance according to claim 1, characterized in that... In step (1), the mass ratio of high amylose corn starch to deionized water is 1:9, the heating temperature is 95℃, and the heating time is 30 minutes.

3. The method for improving the characteristics of starch 3D printing and the product reversion performance according to claim 1, characterized in that... In step (2), the rose polyphenol extract was extracted for 30 min under synchronous ultrasonic conditions with an ultrasonic power of 300 W and a frequency of 20+28 kHz. After ultrasonication, it was centrifuged at 11000 g for 10 min and then passed through an AB-8 macroporous resin column at a flow rate of 1.0 mL / min. It was eluted with 70% ethanol at a flow rate of 1.0 mL / min. After vacuum freeze-drying, the extract was pulverized and passed through an 80-mesh standard sieve.

4. The method for improving the characteristics of starch 3D printing and the product reversion performance according to claim 1, characterized in that... In step (2), the amount of rose extract added is 8% based on dry starch weight, and the cooling temperature is 70°C. The parameters of the multi-mode ultrasonic treatment are: power of 250W, time of 15 minutes, and ultrasonic frequency of three-frequency sequential mode. Sequential mode means that in the three-frequency mode, the three frequencies of 20kHz, 40kHz and 60kHz are switched sequentially every 5 seconds.

5. The method for improving the characteristics of starch 3D printing and the product reversion performance according to claim 1, characterized in that... In step (3), the hydrophilic colloid is selected from xanthan gum, guar gum, carrageenan or gelatin. The amount of xanthan gum added is 2%, the amount of guar gum added is 1.5%, the amount of carrageenan added is 1.5%, and the amount of gelatin added is 1.5%, all based on the dry weight of starch.

6. The method for improving the characteristics of starch 3D printing and the product reversion performance according to claim 1, characterized in that... In step (3), the hydrophilic colloid is homogenized at 9000 rpm for 2 hours, heated to 70°C in a water bath, and then added to the rose polyphenol-high amylose corn starch complex.

7. The method for improving the characteristics of starch 3D printing and the product reversion performance according to claim 1, characterized in that... In step (3), the starch gel is stored at 4°C for 12 hours.

8. The method for improving the characteristics of starch 3D printing and the product reversion performance according to claim 1, characterized in that... In step (4), the 3D printing parameters are: printing speed 20mm / s, number of layers 10, nozzle diameter 1.5mm, and number of revolutions 2.

9. The method for improving the characteristics of starch 3D printing and the product reversion performance according to claim 1, characterized in that... The obtained 3D printed products, when stored at 4℃ or -20℃, showed that the retrogradation inhibition rate remained above 60% after 14 days of storage at -20℃, and the resistant starch content increased by more than 20%.

Images