WO2020233101A1 - Colorful-jelly 4d printing method utilizing spontaneous color change of blueberry anthocyanins - Google Patents

Abstract

A colorful-jelly 4D printing method utilizing spontaneous color change of blueberry anthocyanins, the method comprising: thoroughly mixing two sets of ingredients, respectively; performing preparation, homogenization, gelatination, cooling, material filling, and degassing with respect to the two sets of ingredients, respectively; and using a dual-extruder printer to print out a multi-material color bearing layer and a multi-material color control layer alternately according to a pre-established 3D printing model.

Description

A method for realizing 4D printing of colorful jelly by using blueberry anthocyanin spontaneous color change Technical field

The invention relates to a method for realizing 4D printing of colorful jelly by using blueberry anthocyanin spontaneously changing color, which is mainly used for 3D printing of jelly food containing natural fruit and vegetable anthocyanin, relates to a food processing technology, and belongs to the technical field of food processing.

Background technique

"3D printing", its core principle is to print layer by layer, layer and layer superimposed into a solid pattern. Specifically, 3D printing includes three processes. One is to use computer software, such as CAD, to design three-dimensional patterns; the other is to slice the three-dimensional patterns to form a multilayer two-dimensional plan and the printing track of each layer; It uses the numerical control system to control the printer path and complete the printing. Compared with traditional mold manufacturing methods, 3D printing technology can realize the manufacture of highly complex structure products and improve the accuracy and quality of products, save materials to the greatest extent, design flexibility, and personalize customization. At the same time, it can realize mass customization production and make rapid manufacturing changes. Get economic savings.

As consumers have higher and higher requirements for the taste, appearance and health of food, the degree of customization of food has become higher and higher, making food 3D printing technology more and more concerned and developed. The goal of food 3D printing is a make-to-order production model with higher production efficiency and lower coverage costs. Compared with the traditional supply chain model, the 3D printing supply chain greatly reduces distribution costs and simplifies customized food services.

The so-called 4D printing, to be precise, is a material that can deform automatically. It only needs specific conditions (such as temperature, humidity, etc.) and does not need to connect any complicated electromechanical equipment to produce a fourth-dimensional change according to the product design. This change usually involves color, flavor, and shape. Khoo et al. (2015) proposed that 4D printing is a process of constructing physical objects using appropriate additive manufacturing technology, laying a series of stimulus response composite materials or multi-materials with different properties. After construction, the object responds to stimuli from the natural environment or through human intervention, resulting in changes in the body or chemical state caused by time. 4D printing technology is not only a revolution in production tools, but also a technology that changes the way the entire business ecosystem will change in the future due to changes in production materials. Therefore, it is not just manufacturing technology that will disrupt. However, the current research and application of the concept of 4D printing in the food field is still very limited. The method of blueberry anthocyanin spontaneous discoloration and catalytic discoloration to achieve 4D printing of color jelly is to construct two jelly materials with different properties and lay them through 3D printing technology to make the two materials blend and stimulate each other at the connection point. Spontaneous discoloration occurs to achieve 4D changes, and composite 4D printing is also realized.

Anthocyanins, also known as anthocyanins, are a type of water-soluble natural pigments widely found in plants in nature. They are colored aglycones derived from the hydrolysis of anthocyanins. Most of the main coloring substances in fruits, vegetables and flowers are related to it. Under different pH conditions of plant cell vacuoles, anthocyanins make petals show colorful colors. There is a highly molecular conjugate system in the anthocyanin molecule, which contains acidic and basic groups, and is easily soluble in polar solvents such as water, methanol, ethanol, dilute alkali and dilute acid. Strong absorption in both the ultraviolet and visible regions, the maximum absorption wavelength in the ultraviolet region is 280 Near nm, the maximum absorption wavelength in the visible region is 500～550 Within the nm range. The color of anthocyanins changes with the change of pH value, pH 7 is red, pH=7 to 8 is purple, and pH>11 is blue. Anthocyanins are bioflavonoids, and the main physiological activity of flavonoids is free radical scavenging ability and antioxidant ability. With the development of science and technology, people pay more and more attention to the safety of food additives, and the development and utilization of natural additives has become the general trend of the development and use of additives. Anthocyanins can not only be used as nutritional fortifiers in foods, but also can be used as food preservatives instead of synthetic preservatives such as benzoic acid, and can be used as food colorants in ordinary beverages and foods. It is in line with people's natural, safe, and safe food additives. The general requirement of health.

Li Li et al. (2019) disclosed a food 3D printing material rich in dietary fiber (publication number: CN109198650A). By mixing modified dietary fiber, starch, gluten protein powder, seasoning, water, vegetable oil, gelatin, etc., After grinding to a fineness of less than 20 μm, it is prepared by high-pressure homogenizer treatment. The present invention can reduce the particle size of dietary fiber by performing a series of modification treatments on dietary fiber, while making dietary fiber particles uniform and stable, and improving water solubility The 3D food printing materials prepared have high dietary fiber content. The surface of the dietary fiber is treated with water-soluble to further improve the taste, which can improve the taste and facilitate the absorption of the human body in the preparation of food products by 3D printing, and reduce the labor of the operators. Difficulty and strength, and reduce the maintenance cost of the 3D printer. By adding different auxiliary materials, different flavors of food can be made, which can be applied to a variety of 3D printers, and achieve rapid printing of various flavor materials in a short time, thereby improving the printing efficiency. Xiao Junyong et al. (2018) invented a jelly candy 3D printing material and its preparation method (publication number: CN107668306A). The 3D printing material uses starch and low-acyl gellan gum as gelling agents, which is conducive to remelting and can Quick gelation at room temperature can ensure smooth discharge during 3D printing, and the application of plant extracts can improve the stability of the printed material, so that the printed candies can be stored for a long time and avoid sand inversion. Experiments show that the printing material provided by the invention can be printed smoothly, and the obtained product has a good sensory evaluation, and no anti-sand or tanning phenomenon is seen when placed at room temperature for 60 days. Zhang Yun et al. (2016) disclosed a 3D printing food material for longan rice noodles (publication number: CN106213154A), which belongs to the field of 3D printing materials and consists of the following raw materials by weight: 60 to 70 parts of rice noodles and 5 to 8 parts of longan extract Servings, 8-10 servings of water, 8-10 servings of fresh milk, 8-10 servings of buckwheat flour, 3-5 servings of vegetable oil, 2-3 servings of honey, 2-3 servings of xylitol, 2-3 servings of salt, malt paste 2~3 parts of essence, 2~3 parts of dietary fiber, 1~2 parts of emulsifier, 0.1~0.2 parts of flavor. The invention adopts low-sugar and low-fat raw materials, does not contain chemical additives, is pollution-free, and is healthier. Longan contains a lot of trace elements beneficial to human health, and its main function is to calm the nerves and cure insomnia. The use of 3D printing can realize the diversified, personalized and automated production of products, enriching the types of 3D printing food materials. The use of nanometer rice flour can meet the process requirements of 3D printing; the use of selenium-rich rice flour supplements the selenium required by the human body and meets the needs of different consumers. Zhang Yunjiu et al. (2017) disclosed an ice cream 3D printer, an ice cream 3D printing method and their products (public number: CN106578317A). The ice cream 3D printer includes a printing platform, an X-direction drive device, a Y-direction drive device, a Z-direction drive device, a spray system, a protective cover and a main control device. The ice cream 3D printing method includes: 1) printing a base layer composed of contour lines and ice cream powder; 2) printing a plurality of stacked base layers step by step to obtain 3D printed ice cream. The technical solution provided by the invention can solve the technical problems of long time-consuming and high cost of 3D food printing at this stage. The ice cream 3D printer provided by the invention has a novel structural design and a high degree of automation, which can meet consumers' needs for diversified ice cream food shapes; the technical solution provided by the invention solves the problem of printing an ice cream coat in a few minutes by printing an ice cream coat. The difficulty greatly reduces the printing cost. The above several inventions mainly involve the ratio of different materials for 3D printing and the production and manufacture of machines. Different from the above several inventions, the present invention mainly relates to a method of catalyzing 3D printing with blueberry anthocyanins to achieve color-changing 4D printing.

Ling Weifu (2016) provided a method for preparing color-changing rose tea (publication number: CN107772019A), by washing, pulverizing, pour in alcohol, stirring, filtering, and sedimentation of anthocyanin-rich substances such as black wolfberry, blueberry or mulberry , Discard the residue, centrifugation, heat concentration, re-centrifugation, add alcohol, after obtaining the coloring liquid, perform natural coloring and trypsin treatment on the roses after microwave drying, and quickly perform the coloring process on the roses through open wave drying dry. The beneficial effect is: the finished color-changing rose tea is rich in anthocyanins, which can be quickly precipitated to color the tea during the brewing process, and the color can be changed from dark purple to light purple to dark red to light red to grass green To the colorless change process, simple operation, strong ornamental, high nutrition and health function. Cheng Weili (2018) invented a color-changing functional beverage and its preparation method (publication number: CN108236027A). The color-changing functional beverage is made of anthocyanin embedded powder and lycopene embedded powder as the main raw materials. The microcapsule embedding effect can effectively change the color of the beverage. When the beverage is in a static state, due to the adsorption of porous starch and milk When albumin is embedded, the pigment is adsorbed or embedded, so the beverage is clear and transparent. However, when the beverage is shaken vigorously, the embedded pigment and adsorbed pigment are released due to external force, making the beverage appear gorgeous The green and red colors are very beautiful and can also attract the attention of children and young people. At the same time, because anthocyanins and lycopene have excellent antioxidant activity, they can improve the body’s immunity and delay aging, and also have certain preventive and therapeutic effects on cancer and tumors. Therefore, the beverage of this invention is not only attractive Customers also have health benefits. Huang Bingqiong (2015) invented a color-changing beverage and its processing method (publication number: CN104957702A). The color-changing beverage includes the following parts by weight of raw materials: 130-160 parts of anthocyanin vegetable juice, 5-8 parts of mysterious fruit, 30-45 parts lemon juice, 6-10 parts pine pollen, 1-5 parts agar, 12-17 parts sugar cane juice. The preparation method of the color-changing beverage includes the following steps: raw material pretreatment, stirring pulping, spray granulation, drying, sub-packaging, and finished products. The product of the invention is rich in nutrition and can supplement a variety of vitamins and amino acids necessary for the human body. In particular, the presence of anthocyanins can delay aging and improve immunity, and is especially suitable for supplementing energy for breakfast and afternoon tea. Its color-changing characteristics make the food interesting and romantic, satisfying people's growing material and cultural needs, especially the aesthetic taste of young people. Although the above several inventions all relate to the categories of fruit and vegetable anthocyanins and color-changing foods, the main implementation methods are to achieve beverage color-changing through microcapsules or adsorption and elution methods. Different from the above several inventions, the discoloration involved in this method is that the anthocyanin diffuses between the two materials printed by the dual nozzles, and the discoloration occurs under different environmental pH conditions. It belongs to the blueberry based on 3D printing. The 4D printing category of autonomous discoloration catalyzed by anthocyanins has different discoloration principles.

Zhong Qin (2015) invented a color-changing tea product (publication number: CN105053364A), including the following components by mass: 100 parts of tea plants; 0.01 part-3.33 parts of natural pigments; 0.5 part of edible alkaline additives- 25.0 parts; wherein the natural pigment is at least one of litmus and anthocyanin. When drinking, you can add a certain number of drops of lemon juice or other edible alkaline substances to the tea to change the color. The prepared color-changing tea products have good taste, rich color changes, and have certain health care effects. The preparation method of the tea product is also disclosed, the method is simple, the processing cost is low, and the added value of the tea plant can be increased. Unlike this invention, the color change in this method is realized based on double-jet jelly 3D printing.

Zhang

(2018) disclosed a method of 3D printing two-color sandwich snacks using concentrated fruit pulp (publication number: CN108477540A), which is mainly used for 3D printing of gel foods, involving food processing technology, and belongs to the field of new food processing. The invention first fully mixes the two raw materials, homogenizes, heats them, cools them, and loads them separately, and then uses a dual-jet printer to perform 3D printing according to a pre-made two-color sandwich 3D printing model. The invention adopts dual-nozzle 3D printing, and different models designed can print materials with different spatial shapes and quantities of sandwich effects, so that foods have richer tastes and visual effects, and realize diversified, personalized and automated production of products . Different from the 3D printing two-color dessert method of this method, this method mainly involves the 3D printing of double nozzles of blueberry anthocyanin-rich jelly and lemon thick berry jelly, and the method of color-changing 4D printing is achieved through anthocyanin catalysis.

technical problem

This method is a 4D food printing method that uses anthocyanin catalysis to achieve color change on the basis of food 3D printing, which can enrich 3D printing food ideas and types.

Technical solutions

A method of using blueberry anthocyanins to spontaneously change color to achieve 4D printing of colored jelly is as follows:

(1) Ultrasonic and vacuum extraction of blueberry anthocyanins:

a. Choose fresh, high-quality blueberry fruits and weigh them and freeze them in the refrigerator at -80 ℃;

b. Prepare anthocyanin extractant with hydrochloric acid and ethanol;

c. Mix the frozen fresh blueberry fruit with the anthocyanin extractant in a mass ratio of 1:20;

d. Place the extracted mixture in a low-speed homogenizer to homogenize for 25~35 s and transfer it to a vacuum bottle. Use a vacuum pump to extract the air in the bottle to maintain the air pressure in the bottle at 0.07~0.09 MPa, 10 min to remove oxygen in the extract;

e. Place the vacuum bottle connected to the vacuum pump in an ultrasonic bath at 50~53.5℃ and maintain the air pressure at 0.07~0.09 MPa, extract 25~30 min;

f. Filter the extract and adjust the pH to 7.0~7.2, freeze-dry to obtain anthocyanin powder;

(2) Preparation of color layer materials:

g. Mixing: Add the anthocyanin powder, potato starch, pectin, flavor, and purified water extracted from blueberries in step (1) into the mixer and mix evenly;

h. Homogenization: send the mixed material in step g into the homogenizer, and homogenize for 10-15 min at 3.0-3.5 MPa, so that the particle size of the homogenized material is less than 20 μm;

i. Gelation: Keep the material obtained in step h at 53.5 ℃ for 15-20 min;

j. Cooling: the color-carrying layer material obtained in step i is cooled to normal temperature for use;

(3) Preparation of color layer materials:

k. Mixing: Add lemon juice, NaCO ₃ , pectin and potato starch into the mixer and mix evenly;

1. Homogenization: Send the mixed materials in step k to the homogenizer, and homogenize for 10-15 minutes at 3.0-3.5 MPa, so that the particle size of the homogenized material is less than 20 μm;

m. Gelation: Keep the material obtained in step 1 at 53.5 ℃ for 15-20 min;

n. Cooling: Cool the color control layer material obtained in step m to room temperature for later use;

(4) Filling materials: Load the color-carrying layer and color-controlling layer materials prepared in steps (2) and (3) into two printing cylinders, respectively, and place them in a vacuum of 0.07~0.09 Degas in the vacuum chamber of MPa to remove the bubbles in the barrel;

(5) Printing: Using a dual-nozzle 3D printer, two-material 3D printing is carried out according to the pre-established two-color 3D printing model, and multiple layers of color-carrying layers with different anthocyanin concentrations and different pH values are alternately laid through the dual-nozzle layer by layer. The color-controlling layer material finally forms a 3D-shaped colorful jelly.

In the step b, the matching ratio of the anthocyanin extractant is an aqueous solution of 0.01% HCl and 70% ethanol.

In the step e, the parameters of the ultrasonic generating device when performing the ultrasonic bath are 20-25 kHz, 2 W/g.

In the step f, the freeze-drying conditions are: drying at a cold trap temperature of -80°C and a pressure of 220 Pa for 20-24 hours.

In the step g, the raw material formula is calculated by weight: 1 to 2 parts of anthocyanin powder, 100 to 150 parts of potato starch, 10 to 20 parts of pectin, 0.1 to 0.2 parts of flavor, and 100 parts of purified water;

Said step k, the feed formulation in parts by weight: 100 parts of concentrated lemon juice, NaCO ₃ 0 ~ 7 parts, 10 to 20 parts pectin and potato starch, 75-125 parts;

The starch formed by the gelatinization of potato starch has good gel properties and high transparency; pectin provides elasticity and texture properties for jelly; lemon concentrated juice and lemon essential oil can provide flavor and taste for jelly; NaCO ₃ can adjust and control color The pH of the layer jelly to regulate the color change. The flavor is white lemon essential oil.

The viscosity of the color carrier material is 1500-8000 Pa·s, the elastic modulus is 1800-3200 Pa, the viscosity modulus is 300-500 Pa, and the pH value is 5.1-5.2. The color when the chromophoric layer is formed is expressed in standard Lab as: L *=66.85±2.44, a *=67.44±2.62, b *=-34.61±3.65, purple-red.

The viscosity of the color control layer material is 4300~10000 Pa·s, the elastic modulus is 2600~9200 Pa, the viscosity modulus is 320~1000 Pa, and the pH value is 2.4~11.2. Adjust the final color change by adjusting the pH value of the color control layer. The color of the jelly formed by the final discoloration is represented by the standard Lab value as: L *=59.44±2.76, a *=67.59±8.81, b *=36.66±12.86, when pH=2.4, it is red; L *=50.43±4.50, a *=59.66±12.43, b *=-38.70±6.87, when pH=7, it is purple; L *=27.83±4.19, a *=17.60±6.98, b *=-31.04±12.26, when pH=11.2, Is blue.

In the step (5), the printing speed is 20-25 mm/s, and the extrusion speed is 25-30 mm ³ /s; when printing the bottom layer and shell, the printing speed is 50% of the normal speed; nozzle 2 and nozzle The relative position of 1 is set to X=62.5 mm, Y=-0.5 mm. The diameter of the nozzle of the dual nozzle 3D printer is 0.85 mm.

Beneficial effect

1. This method uses ultrasonic to extract anthocyanins in blueberries in cooperation with vacuum, which can improve the extraction efficiency of anthocyanins while reducing the oxidation of anthocyanins;

2. The anthocyanins extracted from blueberries have good antioxidant properties and bright colors;

3. The present invention is a food 4D color-changing printing method realized on the basis of double nozzle printing and laying;

4. Different jelly materials laid by 3D can migrate and stimulate each other spontaneously to achieve discoloration;

5. By using NaCO _{3 to} adjust the pH of the color control layer, the color control is finally realized;

6. Lay multiple layers of different color-carrying layers and color-controlling layers alternately through double nozzles, and finally realize multi-color changes, so that jelly can change multiple colors at the same time.

7. The gelatinization temperature of the material is 50~53.5 ℃. At this temperature, the potato starch can be fully gelatinized and the loss of anthocyanin is small.

Embodiments of the invention

The following is a further illustration of the present invention in combination with specific examples.

Example 1 : Method for spontaneously changing color of blueberry anthocyanin to realize 4D printing of color jelly (two-color)

Choose fresh, high-quality blueberry fruits and weigh them and freeze them in a refrigerator at -80 ℃. The 0.01% hydrochloric acid and 70% ethanol are formulated into an aqueous solution as the anthocyanin extractant. Mix the fresh frozen blueberry fruit with the extractant in a mass ratio of 1:20, place it in a low-speed homogenizer for 25 s and transfer it to a vacuum bottle. Use a vacuum pump to extract the air in the bottle to maintain the air pressure in the bottle at 0.07 MPa, 10 min to remove oxygen in the extract. Place the vacuum bottle connected to the vacuum pump in an ultrasonic bath at 53.5 ℃, 20 kHz, 2 W/g and maintain the pressure at 0.07 MPa, and the extraction time is 25 min. The extract was filtered and adjusted to pH 7, freeze-dried for 20 h under the conditions of cold trap temperature -80 ℃ and pressure 220 Pa.

Weigh 100 parts of potato starch, 1 part of the blueberry anthocyanin powder extracted above, 20 parts of pectin, 100 parts of purified water and 0.1 part of white lemon essential oil, add them to the mixer and mix them evenly; send the mixed materials into uniform In the mass machine, homogenize at 3.0-3.5 MPa for 10 minutes, so that the particle size of the homogenized material is less than 20 μm. The homogenized material is kept at 53.5 ℃ for 15 min, and then cooled to room temperature to form the color carrier material. The pH when the chromophoric layer was formed was 5.1, lavender ( L *=68.58, a *=69.30, b *=-32.03).

Weigh 75 parts of potato starch, 20 parts of pectin and 100 parts of concentrated lemon juice, add them to the mixer and mix them evenly; send the mixed materials to the homogenizer, homogenize at 3.0 MPa for 10 min, and make the homogenized The particle size of the material is less than 20 μm. The homogenized material was kept at 53.5 ℃ for 15 min, and then cooled to room temperature to prepare the first color control layer material. The pH is 2.4 at this time. Add 4 parts of NaCO _{3 to the} first color control layer material to make the second color control layer material, and the pH is 7 at this time.

Put the three materials into the printing cylinder, fill them evenly, and put them into a vacuum chamber with a vacuum of 0.07 MPa to degas and remove bubbles in the cylinder. For printing, select a nozzle with a diameter of 0.85 mm, set the printing speed to 20 mm/s, and set the extrusion rate to 25 mm ³ /s; set the relative position of nozzle 2 and nozzle 1 to X=62.5 mm, Y=- 0.5 mm. When printing the product shell, set the printing speed to 50% of the normal printing speed. Nozzle 1 prints the color-carrying layer material, and nozzle 2 prints two kinds of color-controlling layer materials alternately, and the pre-designed multi-layer 3D model is based on the color-carrying layer-the first color-controlling layer (pH=2.4)-the color-carrying layer- The second color control layer (pH=7) is printed and laid alternately. The printed jelly can achieve two colors of light red ( L *=61.39, a *=73.81, b *=45.76) and lavender ( L *=53.61, a *=68.45, b *=-33.85) in 2 minutes Variety.

Example 2 : Method for spontaneously changing blueberry anthocyanin to realize 4D printing of color jelly (three colors)

Choose fresh, high-quality blueberry fruits and weigh them and freeze them in a refrigerator at -80 ℃. The 0.01% hydrochloric acid and 70% ethanol are formulated into an aqueous solution as the anthocyanin extractant. Mix the fresh frozen blueberry fruit with the extractant in a mass ratio of 1:20, place it in a low-speed homogenizer for 35 s and transfer it to a vacuum bottle. Use a vacuum pump to extract the air in the bottle to maintain the air pressure in the bottle at 0.09 MPa, 10 min to remove oxygen in the extract. Place the vacuum bottle connected to the vacuum pump in a 52 ℃, 20 kHz, 2 W/g ultrasonic bath and maintain the pressure at 0.09 MPa, and the extraction time is 30 min. The extract was filtered and adjusted to pH 7.2, and freeze-dried for 20 h at a cold trap temperature of -80 ℃ and a pressure of 220 Pa.

Weigh 150 parts of potato starch, 10 parts of pectin, 2 parts of the blueberry anthocyanin powder extracted above, 100 parts of purified water and 0.2 parts of white lemon essential oil, add them to the mixer and mix them evenly; send the mixed materials into the homogeneous In the mass machine, homogenize at 3.5 MPa for 15 minutes so that the particle size of the homogenized material is less than 20 μm. The homogenized material is kept at 53.5 ℃ for 20 min, and then cooled to room temperature to form the color carrier material. The pH when the chromophore was formed was 5.2, and purple ( L *=65.12, a *=65.59, b *=-37.19).

Weigh 100 parts potato starch, 10 parts pectin, 4 parts NaCO ₃ and 100 parts lemon juice concentrate, add them to the mixer and mix them evenly; send the mixed materials to the homogenizer, 3.5 MPa homogenize for 15 min, Make the particle size of the homogeneous material smaller than 20 μm. The homogenized material is kept at 53.5 ℃ for 20 minutes and cooled to room temperature to prepare the first color control layer material with a pH of 2.4; add 4 parts of NaCO _{3 to the} first color control layer material to make The second color control layer material has a pH of 7; on the basis of the first color control layer material, 7 parts of NaCO ₃ are added to make the third color control layer material, the pH is 11.2.

Put 4 kinds of materials into the printing cylinder, fill them evenly, and put them into a vacuum chamber with a vacuum of 0.09 MPa to degas and remove the bubbles in the cylinder. For printing, select a nozzle with a diameter of 0.85 mm, the printing speed is set to 25 mm/s, and the extrusion rate is set to 30 mm ³ /s; nozzle 1 prints the color carrier material, and nozzle 2 prints alternately to print two color control layer materials , Follow the pre-designed multilayer 3D model according to the color carrier-the first color control layer (pH=2.4)-the color carrier-the second color control layer (pH=7)-the color carrier-the third Color control layer (pH=11.2), etc. alternately printed and laid. The printed jelly can achieve red ( L *=57.48, a *=61.36, b *=27.56), purple ( L *=47.25, a *=50.87, b *=-43.56), blue ( L *=-43.56) in 2 minutes. =24.86, a *=12.67, b *=-39.71) Three color changes.

Example 3 : Method for spontaneously changing color of blueberry anthocyanin to realize 4D printing of color jelly (six colors)

Choose fresh, high-quality blueberry fruits and weigh them and freeze them in a refrigerator at -80 ℃. The 0.01% hydrochloric acid and 70% ethanol are formulated into an aqueous solution as the anthocyanin extractant. Mix the frozen fresh blueberry fruit with the extractant in a mass ratio of 1:20, and place it in a low-speed homogenizer to homogenize 25~35 s and transfer to a vacuum bottle, use a vacuum pump to extract the air in the bottle, and maintain the air pressure in the bottle at 0.08 MPa for 10 min to remove the oxygen in the extract. Place the vacuum bottle connected to the vacuum pump in a 50 ℃, 20 kHz, 2 W/g ultrasonic bath and maintain the air pressure at 0.08 MPa, and the extraction time is 25 min. The extract was filtered and adjusted to pH 7, freeze-dried for 24 h at a cold trap temperature of -80 ℃ and a pressure of 220 Pa.

Weigh 125 parts of potato starch, 15 parts of pectin, 1 part of the blueberry anthocyanin powder extracted above, 100 parts of purified water and 0.2 parts of white lemon essential oil, add them to the mixer and mix them evenly; send the mixed materials into uniform In the mass machine, homogenize at 3.5 MPa for 15 minutes so that the particle size of the homogenized material is less than 20 μm. The homogenized material was kept at 53.5 ℃ for 20 min, and then cooled to room temperature to make the first color carrier material. The pH when the first color carrier is formed=5.1, lavender ( L *=68.58, a *=69.30, b *=-32.03); add 1 more of the above on the basis of the first color carrier material The extracted blueberry anthocyanin powder is made into the second color-carrying layer material, the pH when the layer is formed=5.2, purple-red ( L *=65.12, a *=65.59, b *=-37.19).

Weigh 125 parts of potato starch, 15 parts of pectin and 100 parts of concentrated lemon juice, add them to the mixer and mix them evenly; send the mixed materials to the homogenizer, and homogenize at 3.5 MPa for 15 minutes to make the homogenized The particle size of the material is less than 20 μm. The homogenized material is kept at 53.5 ℃ for 20 minutes and cooled to room temperature to make the first color control layer material with a pH of 2.4; add 4 parts of NaCO _{3 to the} first color control layer material to make The second color control layer material has a pH of 7; on the basis of the first color control layer material, 7 parts of NaCO ₃ are added to make the third color control layer material, the pH is 11.2.

Put 5 kinds of materials into the printing cylinder, fill them evenly, and put them into a vacuum chamber with a vacuum of 0.08 MPa to degas and remove the bubbles in the cylinder. For printing, select a nozzle with a diameter of 0.85 mm, set the printing speed to 20 mm/s, and set the extrusion rate to 30 mm ³ /s; set the relative position of nozzle 2 and nozzle 1 to X=62.5 mm, Y=- 0.5 mm. When printing the product shell, set the printing speed to 50% of the normal printing speed. The pre-designed multi-layer 3D model is printed alternately with different color-carrying layers and color-controlling layers to form. The printed jelly can achieve light red ( L *=61.39, a *=73.81, b *=45.76), lavender ( L *=53.61, a *=68.45, b *=-33.85), light blue in 2 minutes ( L *=30.79, a *=22.53, b *=-22.369), red ( L *=57.48, a *=61.36, b *=27.56), purple ( L *=47.25, a *=50.87, b * =-43.56), blue ( L *=24.86, a *=12.67, b *=-39.71) six color changes.

Claims (10)

1. A method for realizing 4D printing of colorful jelly by using blueberry anthocyanin spontaneous color change, which is characterized in that the details are as follows:

   (1) Ultrasonic and vacuum extraction of blueberry anthocyanins:

   a. Choose fresh, high-quality blueberry fruits and weigh them and freeze them in the refrigerator at -80 ℃;

   b. Prepare anthocyanin extractant with hydrochloric acid and ethanol;

   c. Mix the frozen fresh blueberry fruit with the anthocyanin extractant in a mass ratio of 1:20;

   d. Place the extraction mixture in a low-speed homogenizer to homogenize for 25~35 s and transfer to a vacuum bottle. Use a vacuum pump to extract the air in the bottle and maintain the air pressure in the bottle at 0.07~0.09 MPa for 10 min to remove the extraction liquid. Oxygen;

   e. Place the vacuum bottle connected to the vacuum pump in an ultrasonic bath at 50~53.5 ℃ and maintain the air pressure at 0.07~0.09 MPa, and extract for 25~30 min;

   f. Filter the extract and adjust the pH to 7.0~7.2, freeze-dry to obtain anthocyanin powder;

   (2) Preparation of color layer materials:

   g. Mixing: Add the anthocyanin powder, potato starch, pectin, flavor, and purified water extracted from blueberries in step (1) into the mixer and mix evenly;

   h. Homogenization: send the mixed materials in step g into the homogenizer, 3.0~3.5 Homogenize for 10~15 min under MPa, so that the particle size of the homogenized material is less than 20 μm;

   i. Gelation: Keep the material obtained in step h at 53.5 ℃ for 15-20 min;

   j. Cooling: the color-carrying layer material obtained in step i is cooled to normal temperature for use;

   (3) Preparation of color layer materials:

   k. Mixing: Add lemon juice, NaCO ₃ , pectin and potato starch into the mixer and mix evenly;

   l. Homogenization: send the mixed materials in step k to the homogenizer, 3.0~3.5 Homogenize for 10-15 minutes at MPa, so that the particle size of the homogenized material is less than 20 μm;

   m. Gelation: Keep the material obtained in step 1 at 53.5 ℃ for 15-20 min;

   n. Cooling: Cool the color control layer material obtained in step m to room temperature for later use;

   (4) Filling materials: Put the color-carrying layer and color-controlling layer materials prepared in steps (2) and (3) into two printing cylinders respectively, and place them in a vacuum chamber with a vacuum of 0.07~0.09 MPa Internal degassing to remove bubbles in the barrel;

   (5) Printing: Using a dual-nozzle 3D printer, two-material 3D printing is carried out according to the pre-established two-color 3D printing model, and multiple layers of color-carrying layers with different anthocyanin concentrations and different pH values are alternately laid through the dual-nozzle layer by layer. The color-controlling layer material finally forms a 3D-shaped colorful jelly.
2. The method of using blueberry anthocyanin spontaneous color change to realize 4D printing of color jelly according to claim 1, wherein in step b, the matching ratio of the anthocyanin extractant is 0.01% HCl, 70% ethanol In the step e, the parameters of the ultrasonic generator during the ultrasonic bath are 20-25 kHz, 2 W/g; in the step f, the freeze-drying conditions are: cold trap temperature -80 ℃, pressure 220 Pa Dry under the conditions for 20-24 h.
3. The method of using blueberry anthocyanin to spontaneously change color to achieve 4D printing of color jelly according to claim 1 or 2, characterized in that, in the step g, the raw material formula is: anthocyanin powder 1~ 2 parts, 100~150 parts of potato starch, 10~20 parts of pectin, 0.1~0.2 parts of flavor, 100 parts of purified water; in the step k, the raw material formula is calculated by weight: 100 parts of lemon juice, NaCO ₃ 0~7 parts, 10~20 parts of pectin and 75~125 parts of potato starch.
4. The method for realizing 4D printing of color jelly by using blueberry anthocyanin spontaneous color change according to claim 1 or 2, characterized in that the viscosity of the color carrier material is 1500~8000 Pa·s, and the elastic modulus is 1800 ~3200 Pa, viscosity modulus is 300~500 Pa, pH value is 5.1~5.2; the color when the color carrier is formed is expressed by standard Lab: L *=66.85±2.44, a *=67.44±2.62, b *= -34.61±3.65, purple-red.
5. The method for realizing 4D printing of color jelly by using blueberry anthocyanin spontaneous color change according to claim 3, wherein the viscosity of the color carrier material is 1500~8000 Pa·s, and the elastic modulus is 1800~3200 Pa, viscosity modulus is 300~500 Pa, pH value is 5.1~5.2; the color when the color-carrying layer is formed is expressed by standard Lab as: L *=66.85±2.44, a *=67.44±2.62, b *=-34.61 ±3.65, purple red.
6. The method of using blueberry anthocyanin to spontaneously change color to achieve 4D printing of colored jelly according to claim 1, 2 or 5, wherein the viscosity of the color control layer material is 4300~10000 Pa·s, and the elastic modulus It is 2600~9200 Pa, the viscosity modulus is 320~1000 Pa, and the pH value is 2.4~11.2; the final color change can be adjusted by adjusting the pH value of the color control layer; the color of the jelly formed by the final color change is represented by the standard Lab value: L *=59.44±2.76, a *=67.59±8.81, b *=36.66±12.86, when pH=2.4, it is red; L *=50.43±4.50, a *=59.66±12.43, b *=-38.70±6.87 When pH=7, it is purple; L *=27.83±4.19, a *=17.60±6.98, b *=-31.04±12.26, when pH=11.2, it is blue.
7. The method for realizing 4D printing of color jelly by using blueberry anthocyanin spontaneous color change according to claim 3, wherein the viscosity of the color control layer material is 4300~10000 Pa·s, and the elastic modulus is 2600~9200 Pa, the viscosity modulus is 320~1000 Pa, the pH value is 2.4~11.2; the final color change is adjusted by adjusting the pH value of the color control layer; the color of the jelly formed by the final color change is represented by the standard Lab value: L *=59.44 ±2.76, a *=67.59±8.81, b *=36.66±12.86, when pH=2.4, it is red; L *=50.43±4.50, a *=59.66±12.43, b *=-38.70±6.87, pH=7 When L *=27.83±4.19, a *=17.60±6.98, b *=-31.04±12.26, when pH=11.2, it is blue.
8. The method for realizing 4D printing of colored jelly by using blueberry anthocyanin spontaneous color change according to claim 4, wherein the viscosity of the color control layer material is 4300~10000 Pa·s, and the elastic modulus is 2600~9200 Pa, the viscosity modulus is 320~1000 Pa, the pH value is 2.4~11.2; the final color change is adjusted by adjusting the pH value of the color control layer; the color of the jelly formed by the final color change is represented by the standard Lab value: L *=59.44 ±2.76, a *=67.59±8.81, b *=36.66±12.86, when pH=2.4, it is red; L *=50.43±4.50, a *=59.66±12.43, b *=-38.70±6.87, pH=7 When L *=27.83±4.19, a *=17.60±6.98, b *=-31.04±12.26, when pH=11.2, it is blue.
9. The method for realizing 4D printing of color jelly using blueberry anthocyanin spontaneous color change according to claim 1, 2, 5, 7 or 8, characterized in that, in the step (5), the printing speed is 20-25 mm/s, the extrusion speed is 25~30 mm ³ /s; when printing the bottom layer and shell, the printing speed is 50% of the normal speed; the relative position of nozzle 2 and nozzle 1 is set to X=62.5 mm, Y= -0.5 mm; the diameter of the nozzle of the dual nozzle 3D printer is 0.85 mm.
10. The method of using blueberry anthocyanins to spontaneously change color to achieve 4D printing of color jelly according to claim 6, wherein in the step (5), the printing speed is 20-25 mm/s, and the extrusion speed is 25~30 mm ³ /s; when printing the bottom layer and shell, the printing speed is 50% of the normal speed; the relative position of nozzle 2 and nozzle 1 is set to X=62.5 mm, Y=-0.5 mm; dual-nozzle 3D printer The nozzle diameter is 0.85 mm.