A natural starch-based oil gel suitable for 3D printing and a method of preparing the same

Abstract

The application discloses a natural starch-based oil gel suitable for 3D printing and a preparation method thereof, and belongs to the technical field of food processing. The preparation of the natural starch-based oil gel suitable for 3D printing comprises the following steps: mixing natural starch particles and oil, and stirring at high speed through a stator-rotor disperser to obtain a starch-oil suspension; then adding water to the starch-oil suspension, and stirring at high speed through the stator-rotor disperser again to obtain an oil gel. The preparation process is simple, the oil gel with high unsaturated fat content is produced, and the oil gel has the properties of solid fat and can be used as a substitute for solid fat in various 3D printed foods; and the gel used is natural starch, which is a kind of polysaccharide with low cost, no safety hazards and important constant nutrients in human body, and has very high application value for industrial production.

Description

Technical Field

[0001] The present invention relates to a natural starch-based oil gel suitable for 3D printing and a preparation method thereof, belonging to the technical field of food processing. Background Art

[0002] In the food processing industry, plastic fats play a vital role in most lipid-based foods due to their elastic properties. However, these fats are often derived from oils and fats rich in trans and saturated fatty acids. Excessive intake can have adverse effects on human health and may even lead to various metabolic and cardiovascular diseases.

[0003] Oleogelation is a highly promising manufacturing technology that can replace traditional fats. By using oleogels to form a stable three-dimensional network in the oil, liquid oil is converted into a gel-like substance without changing its chemical properties. Moreover, due to its good thixotropic and shear-thinning properties, it can be used as an ink for 3D printing to personalize the printing of foods with good plastic fat replacement properties, which has become a research hotspot in the food field.

[0004] The traditional oil gel construction technology is to directly use oil-soluble small molecule gelling agents, such as beeswax, glycerides, fatty acids and their derivatives, for the gelation construction of liquid oil, but this requires higher temperature and gelling agent concentration, which is not allowed by food health requirements.

[0005] Starch is an important macronutrient polysaccharide and is considered to be an abundant and sustainable natural material. It is of great significance in the preparation of edible oil gels. The porous structure of starch aerogels is used to adsorb liquid oil to construct oil gels, but its adsorption force often finds it difficult to overcome the influence of gravity, and obvious oil leakage will occur during long-term storage. By utilizing the interfacial properties of sodium starch octenylsuccinate anhydride, a stable water-in-oil emulsion is formed, which is then dried and sheared to form an oil gel. However, it is often difficult to control the rheological properties of the oil gel due to large deformations during the dehydration process and the shearing process, which is not conducive to its application in 3D printing. In addition, the potential risks brought by chemical modification are also abandoned by people, and the process flow of the above methods is complicated and the industrialization cost is too high. Summary of the Invention

[0006] In response to the defects and shortcomings of the existing technology, the present invention provides a natural starch-based oil gel suitable for 3D printing and a preparation method thereof. The method is simple in process, has no safety risks, and the prepared oil gel has excellent stability and controllable rheology, and has good 3D printing performance.

[0007] The present invention prepares a natural starch-based oleogel by utilizing the structuring technology of capillary suspensions. The principle is to add a small amount of immiscible secondary fluid (water) to the starch-oil dispersion. Rapid stirring by a stator-rotor disperser causes the water to spontaneously form a capillary bridge network spanning the space between the starch particles. This transformation originates from the capillary forces formed between the particles by a small number of fluids, causing the fluid state of the dispersion to change to an oleogel with a strong network structure. Its stability and rheological properties are regulated by the content of particles and secondary fluids. Given its excellent rheological controllability, it can be applied to the development of new solid oils in 3D printing and has good application prospects in the field of healthy foods.

[0008] The first object of the present invention is to provide a method for preparing a natural starch-based oil gel suitable for 3D printing, the method comprising the following steps:

[0009] (1) mixing natural starch granules with oil and stirring at high speed by a stator-rotor disperser to obtain a starch-oil suspension;

[0010] (2) adding water to the starch-oil suspension obtained in step (1), stirring the suspension at high speed again using a stator-rotor disperser to obtain an oil gel.

[0011] In one embodiment, the natural starch in step (1) is one or more of corn starch, waxy corn starch, pea starch, potato starch and tapioca starch.

[0012] In one embodiment, the natural starch in step (1) is corn starch.

[0013] In one embodiment, the oil in step (1) includes vegetable oil and animal oil.

[0014] In one embodiment, the vegetable oil comprises one or more of soybean oil, rapeseed oil, palm oil, peanut oil, sesame oil and sunflower oil.

[0015] In one embodiment, the animal fat comprises one or more of lard, mutton fat and beef tallow.

[0016] In one embodiment, the oil in step (1) is soybean oil.

[0017] In one embodiment, the high-speed stirring in step (1) is performed at a speed of 9000-15000 rpm for 1-5 minutes.

[0018] In one embodiment, the high-speed stirring in step (1) is performed at a speed of 10,000-12,000 rpm for 2-3 minutes.

[0019] In one embodiment, the high-speed stirring in step (1) is performed at a speed of 12000 rpm for 3 minutes.

[0020] In one embodiment, the ratio of the natural starch to the oil in step (1) is 0.24 to 0.38 g of natural starch per 1 ml of oil.

[0021] In one embodiment, the ratio of the natural starch to the oil in step (1) is 0.32 to 0.38 g of natural starch per 1 ml of oil.

[0022] In one embodiment, the ratio of the natural starch to the oil in step (1) is 0.32 g of natural starch per 1 ml of oil.

[0023] In one embodiment, the ratio of the natural starch to the oil in step (1) is 0.35 g of natural starch per 1 ml of oil.

[0024] In one embodiment, the amount of water added in step (2) is 10-50% based on the mass of the natural starch.

[0025] In one embodiment, the amount of water added in step (2) is 15-40% based on the mass of the natural starch.

[0026] In one embodiment, the amount of water added in step (2) is 20-30% based on the mass of the natural starch.

[0027] In one embodiment, the amount of water added in step (2) is 25% based on the mass of the native starch.

[0028] In one embodiment, the high-speed stirring in step (2) is performed at a speed of 9000-12000 rpm for 1-5 minutes.

[0029] In one embodiment, the high-speed stirring in step (2) is performed at a speed of 12000 rpm for 3 minutes.

[0030] The second object of the present invention is to provide a natural starch-based oil gel prepared by the above method.

[0031] The third object of the present invention is to provide a use of the above-mentioned natural starch-based oil gel in the preparation of 3D printed food.

[0032] In one embodiment, the 3D printed food includes 3D printed baked cookies and 3D printed chocolate products.

[0033] The fourth object of the present invention is to provide a use of the above-mentioned natural starch-based oil gel as a substitute for baking bread and cookie butter, an oil-soluble drug carrier, and an alternative to animal fat products.

[0034] Beneficial effects of the present invention:

[0035] (1) The present invention cleverly utilizes a stator-rotor disperser to uniformly disperse a small amount of immiscible secondary fluid (water) into a starch-oil suspension, causing the water to spontaneously form a capillary bridge network spanning the space between the starch particles. The capillary force formed by the small amount of water between the particles ultimately significantly changes its rheological properties, structuring the liquid oil and preparing a natural starch-based oil gel with controllable rheological properties by changing the conditions.

[0036] (2) The present invention produces an oil gel with a high unsaturated fat content through a simple preparation process. The oil gel has the properties of solid fat and can be used as a solid fat substitute in various foods. In addition, the gelling agent used is natural starch, which is a low-cost, safety-protective polysaccharide that is an important macronutrient in the human body and has great application value in industrial production.

[0037] (3) The present invention can also prepare solid fat substitutes by food 3D printing, which can achieve product diversification, customization and automation, and meet the personalized needs of different consumers. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Appearance and oil loss diagrams of the oil gels prepared in Examples 1-6 and Comparative Examples 1-2 using 0.32 g / mL native corn starch as the gelling agent at different water addition and starch mass ratios; a) is the appearance diagram; b) is the oil loss diagram;

[0039] Figure 2 Graphs showing the elastic modulus and viscous modulus of oil gels prepared in Examples 1-6 and Comparative Examples 1-2 using 0.32 g / mL native corn starch as a gelling agent at different water addition to starch mass ratios; a) is the elastic modulus graph; b) is the viscous modulus graph;

[0040] Figure 3 3D prints of oil gels prepared in Examples 1-6 and Comparative Examples 1-2 using 0.32 g / mL natural corn starch as a gelling agent at different water addition amounts and starch mass ratios;

[0041] Figure 4 Appearance and oil loss diagrams of the oil gels prepared in Examples 1, 7-10 and Comparative Examples 3-4 using different masses of natural corn starch as the gelling agent at a water to starch mass ratio of 0.2; a) is the appearance diagram; b) is the oil loss diagram;

[0042] Figure 5 Graphs showing the elastic modulus and viscous modulus of oil gels prepared in Examples 1, 7-10 and Comparative Examples 3-4 using different masses of native corn starch as a gelling agent at a water to starch mass ratio of 0.2; a) is the elastic modulus graph; b) is the viscous modulus graph;

[0043] Figure 6 3D prints of oil gels prepared in Examples 1, 7-10 and Comparative Examples 3-4 using different masses of natural corn starch as a gelling agent at a water to starch mass ratio of 0.2;

[0044] Figure 7 Graphs showing the data for oil gels prepared in Example 2 and Examples 11-14 using 0.32 g / mL of different types of natural starch as gelling agents at a water to starch mass ratio of 0.25; a) is an appearance graph; b) is a graph showing the elastic modulus and viscous modulus;

[0045] Figure 8 3D prints of oil gels prepared in Example 2 and Examples 11 to 14 using 0.32 g / mL of different types of natural starch as gelling agents and a water to starch mass ratio of 0.25;

[0046] Figure 9 This is the appearance of the oil gel prepared in Comparative Example 5 using 0.32 g / mL native corn starch as the gelling agent without adding water;

[0047] Figure 10 This is the appearance of the oil gel prepared using 0.32 g / mL native corn starch as a gelling agent using a magnetic stirrer in Comparative Example 6;

[0048] Figure 11 Data graphs showing the oleogel formed in Comparative Example 7 using 0.32 g / mL native corn starch as the gelling agent, first adding 25% water by mass to the starch, mixing well, and then adding soybean oil; a) is the appearance image; b) is the rheological graph; c) is the 3D printed image;

[0049] Figure 12 Data graphs for the oil gels prepared in Example 2 and Comparative Example 8 using 0.32 g / mL of different types of protein as gelling agents and a water to protein ratio of 0.25; a) is an appearance graph; b) is a 3D print graph; c) is a graph of the elastic modulus and viscous modulus. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are clearly and completely described below in conjunction with specific embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] The testing method of the present invention

[0052] 1. Rheological determination method

[0053] The rheological properties of starch oleogel were analyzed using a TA-type rotational rheometer. The fixtures used were 40 mm diameter aluminum plates with a 1 mm test gap. The starch oleogel sample was evenly applied between the upper and lower grips of the rheometer, and excess sample was removed along the edges. A frequency sweep was performed in the range of 0.1–100 rad / s, with a strain of 0.1%. G' and G" values ​​were recorded throughout the test.

[0054] 2. Oil loss determination method

[0055] The starch oil gel sample was weighed in a centrifuge tube and centrifuged at 4000 rpm for 2 minutes; the percentage of precipitated oil in the total mass before centrifugation was calculated.

[0056] 3. Method for measuring 3D printing performance

[0057] The printability of the oleogel was evaluated by printing letter shapes at a speed of 15 mm / s using a nozzle tip with a diameter of 0.40 mm; the temperature was maintained at 25 °C during the printing process.

[0058] Example 1

[0059] A method for preparing a natural starch-based oil gel comprises the following steps:

[0060] (1) Mixing native corn starch and soybean oil at a solid content of 0.32 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0061] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 20% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0062] Example 2

[0063] A method for preparing a natural starch-based oil gel comprises the following steps:

[0064] (1) Mixing native corn starch and soybean oil at a solid content of 0.32 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0065] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 25% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0066] Example 3

[0067] A method for preparing a natural starch-based oil gel comprises the following steps:

[0068] (1) Mixing native corn starch and soybean oil at a solid content of 0.32 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0069] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 10% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0070] Example 4

[0071] A method for preparing a natural starch-based oil gel comprises the following steps:

[0072] (1) Mixing native corn starch and soybean oil at a solid content of 0.32 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0073] (2) adding water in an amount of 15% of the mass of the starch to the natural corn starch suspension obtained in step (1), and then stirring again with a stator-rotor disperser at a high speed of 12000 rpm for 3 minutes to obtain a natural starch-based oil gel.

[0074] Example 5

[0075] A method for preparing a natural starch-based oil gel comprises the following steps:

[0076] (1) Mixing native corn starch and soybean oil at a solid content of 0.32 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0077] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 30% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0078] Example 6

[0079] A method for preparing a natural starch-based oil gel comprises the following steps:

[0080] (1) Mixing native corn starch and soybean oil at a solid content of 0.32 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0081] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 40% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0082] Comparative Example 1

[0083] A method for preparing a natural starch-based oil gel comprises the following steps:

[0084] (1) Mixing native corn starch and soybean oil at a solid content of 0.32 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0085] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 5% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0086] Comparative Example 2

[0087] A method for preparing a natural starch-based oil gel comprises the following steps:

[0088] (1) Mixing native corn starch and soybean oil at a solid content of 0.32 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0089] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 50% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0090] The performance of the natural starch-based oil gel prepared in Examples 1 to 6 and Comparative Examples 1 to 2 was measured.

[0091] The results are as follows Figure 1 As shown, from Figure 1 It can be seen from a) that when the amount of water added is 5%, the oil gel has obvious flow phenomenon; when the amount of water added exceeds 10%, the starch oil gel shows stable gel properties. Figure 1 As can be seen from b), the oil holding capacity is the strongest at 25%.

[0092] Gel properties such as Figure 2 As shown in the figure, as the water content increases to 25%, the elastic modulus and viscous modulus increase to 34KPa-60KPa and 5KPa-9KPa, respectively. As the water content continues to increase, the elastic modulus and viscous modulus decrease to 14KPa-25KPa and 2KPa-5KPa, respectively. This shows that with the increase in water content, the rheological properties show a trend of first increasing and then decreasing, indicating that the amount of water added can regulate the rheological properties of natural starch oil gel.

[0093] 3D printing performance such as Figure 3 As shown, as the amount of water added increases, its printing accuracy is consistent with the trend of rheological properties, showing a trend of first increasing and then decreasing. It shows good printing accuracy at a water addition of 20%-30%, especially at a water addition of 25%, the printing accuracy is the highest. This shows that the capillary bridge structure of the oil gel is most stable at this time and can withstand the high shear force generated during the extrusion process; as the water content continues to increase to 40%, most of the starch particles in the oil gel system aggregate and cannot form a uniform capillary bridge structure, so it is difficult to resist the shear force during the printing process, and obvious oil leakage occurs; however, when the water addition is less than 20%, it has a small amount of capillary bridge structure, so it is also difficult to withstand the shear force during the printing process.

[0094] Example 7

[0095] A method for preparing a natural starch-based oil gel comprises the following steps:

[0096] (1) Mixing native corn starch and soybean oil at a solid content of 0.24 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0097] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 20% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0098] Example 8

[0099] A method for preparing a natural starch-based oil gel comprises the following steps:

[0100] (1) Mixing native corn starch and soybean oil at a solid content of 0.28 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0101] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 20% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0102] Example 9

[0103] A method for preparing a natural starch-based oil gel comprises the following steps:

[0104] (1) Mixing native corn starch and soybean oil at a solid content of 0.35 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0105] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 20% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0106] Example 10

[0107] A method for preparing a natural starch-based oil gel comprises the following steps:

[0108] (1) Mixing native corn starch and soybean oil at a solid content of 0.38 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0109] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 20% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0110] Comparative Example 3

[0111] A method for preparing a natural starch-based oil gel comprises the following steps:

[0112] (1) Mixing native corn starch and soybean oil at a solid content of 0.19 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0113] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 20% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0114] Comparative Example 4

[0115] A method for preparing a natural starch-based oil gel comprises the following steps:

[0116] (1) Mixing native corn starch and soybean oil at a solid content of 0.41 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a native corn starch suspension with oil as the continuous phase;

[0117] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 20% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0118] The performance of the natural starch-based oil gel prepared in Examples 1, 7 to 10 and Comparative Examples 3 to 4 was measured.

[0119] The results are as follows Figure 4 As shown, from Figure 4 a) It can be seen that with the increase of solid content, the stability of natural starch oil gel is stronger, and Figure 4 As shown in b), the starch oil gel with high solid content only exhibits slight oil leakage under the action of centrifugal force.

[0120] Gel properties such as Figure 5 As shown, their elastic modulus increases with increasing solids content. When the solids content increases to 41%, the elastic modulus and viscous modulus reach 110 kPa-201 kPa and 18 kPa-41 kPa, respectively. This indicates that adjusting the solids content can also change the rheological properties of starch oil gels, and the changes are greater than those caused by adjusting the water addition.

[0121] 3D printing performance such as Figure 6As shown in the figure, printing accuracy increases linearly with increasing solids content up to 38%. It exhibits good printing accuracy at solids content between 32% and 38%, with the highest accuracy achieved at 35%. This indicates the formation of a uniform capillary bridge structure capable of withstanding the high shear forces generated during extrusion. As the solids content continues to increase to 41%, the capillary bridge structure in the oil gel system becomes too dense, causing some aggregates to form during extrusion, resulting in a decrease in the precision of the 3D printed product. However, at solids content below 32%, a small amount of capillary bridge structure remains, making it difficult to withstand the high shear forces during extrusion.

[0122] Example 11

[0123] A method for preparing a natural starch-based oil gel comprises the following steps:

[0124] (1) Waxy corn starch and soybean oil were mixed at a solid content of 0.32 g / mL and stirred at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a natural corn starch suspension with oil as the continuous phase;

[0125] (2) adding water in an amount of 25% of the mass of the starch to the waxy corn starch suspension obtained in step (1), and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0126] Example 12

[0127] A method for preparing a natural starch-based oil gel comprises the following steps:

[0128] (1) Pea starch and soybean oil were mixed at a solid content of 0.32 g / mL and stirred at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a natural corn starch suspension with oil as the continuous phase;

[0129] (2) adding water to the potato starch suspension obtained in step (1) in an amount of 25% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0130] Example 13

[0131] A method for preparing a natural starch-based oil gel comprises the following steps:

[0132] (1) Potato starch and soybean oil were mixed at a solid content of 0.32 g / mL and stirred at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a natural corn starch suspension with oil as the continuous phase;

[0133] (2) adding water to the cassava starch suspension obtained in step (1) in an amount of 25% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0134] Example 14

[0135] A method for preparing a natural starch-based oil gel comprises the following steps:

[0136] (1) Cassava starch and soybean oil were mixed at a solid content of 0.32 g / mL and stirred at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a natural corn starch suspension with oil as the continuous phase;

[0137] (2) adding water to the cassava starch suspension obtained in step (1) in an amount of 25% of the mass of the starch, and then stirring again at a high speed of 12000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0138] The performance of the natural starch-based oil gel prepared in Example 2 and Examples 11 to 14 was measured.

[0139] The results are as follows Figure 7 As shown, Figure 7 As shown in a), they can all form oil gels without obvious oil leakage. Their rheological properties are as follows Figure 7 As shown in b), the elastic moduli are not much different and are all greater than the viscous modulus, indicating that these natural starches can form oil gels.

[0140] 3D printing performance such as Figure 8 As shown, their printing accuracy, although slightly lower than that of corn starch oil gel, can still maintain its shape, which is mainly attributed to the affinity of starch particles for water molecules and particle size.

[0141] Comparative Example 5

[0142] A method for preparing a natural starch-based oil gel comprises the following steps:

[0143] (1) Mixing natural corn starch and soybean oil at a solid content of 0.32 g / mL, stirring at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a natural corn starch suspension with oil as the continuous phase;

[0144] (2) adding water to the natural corn starch suspension obtained in step (1) so that the amount of water added is 0% of the mass of the starch, and then stirring again with a stator-rotor disperser at a high speed of 12000 rpm for 3 minutes to obtain the product.

[0145] This comparative example could not obtain a gel-like product. Figure 9 As shown, it is shown that the addition of a small amount of water is crucial in the preparation process of the present invention.

[0146] Comparative Example 6

[0147] A method for preparing a natural starch-based oil gel comprises the following steps:

[0148] (1) Mix native corn starch and soybean oil to a solid content of 0.32 g / mL and stir at 800 rpm for 3 min using a magnetic stirrer to obtain a native corn starch suspension with oil as the continuous phase;

[0149] (2) adding water to the natural corn starch suspension obtained in step (1) in an amount of 20% of the mass of the starch, and then stirring again at 800 rpm with a magnetic stirrer for 3 minutes to obtain a natural starch-based oil gel.

[0150] This comparative example also cannot obtain stable gel-like product, such as Figure 10 As shown, it cannot be used for 3D printing.

[0151] Comparative Example 7

[0152] A method for preparing a natural starch-based oil gel comprises the following steps:

[0153] (1) Mixing native corn starch and water in an amount of water equal to 20% of the mass of the starch, and stirring at a high speed of 12,000 rpm for 3 minutes using a stator-rotor disperser to obtain a native corn starch suspension;

[0154] (2) adding soybean oil to the natural corn starch suspension obtained in step (1) (adding 1 ml of soybean oil for every 0.32 g of natural corn starch), and then stirring again at a high speed of 12,000 rpm for 3 minutes using a stator-rotor disperser to obtain a natural starch-based oil gel.

[0155] The performance of the natural starch-based oil gel prepared in Example 2 and Comparative Example 7 was measured.

[0156] The results are as follows Figure 11 As shown in a), the method of comparative example 7 can also form oil gel without obvious oil leakage. Its rheological properties are as follows Figure 11 b), its elastic modulus is lower than that of Example 2, and its viscous modulus is almost similar. Its 3D printing performance is as follows Figure 11 c), their printing accuracy and stability are much lower than the oil gel prepared in Example 2.

[0157] Comparative Example 8

[0158] A method for preparing a natural starch-based oil gel comprises the following steps:

[0159] (1) Zein, pea protein, or soy protein were mixed with soybean oil at a solid content of 0.32 g / mL, and stirred at 12,000 rpm for 3 min using a stator-rotor disperser to obtain a protein suspension with oil as the continuous phase;

[0160] (2) adding water to the protein suspension obtained in step (1) in an amount of 25% of the mass of the starch, and then stirring again at a high speed of 12,000 rpm for 3 minutes using a stator-rotor disperser to obtain a protein-based oil gel.

[0161] The performance of the oil gel prepared in Example 2 and Comparative Example 8 was measured.

[0162] The results are as follows Figure 12 As shown in the figure, they can all maintain gel-like behavior in the induced state and there is no oil leakage. The elastic modulus and viscous modulus of the protein oil gel are slightly higher than those of the starch oil gel; however, none of them can be printed and are not printable. This shows that despite having high rheological properties, their capillary strength cannot withstand the high shear force during the printing process, which is attributed to the affinity for water molecules and the particle size.

[0163] The embodiments provided above are not intended to limit the scope of the present invention, nor are the steps described to limit their execution order. Any obvious improvements to the present invention made by those skilled in the art in combination with existing common knowledge shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a natural starch-based oil gel suitable for 3D printing, characterized in that: The method comprises the following steps: (1) Mixing natural starch with vegetable oil and stirring at high speed using a stator-rotor disperser to obtain a starch-oil suspension; The high-speed stirring speed is 9000-15000 rpm, and the time is 1-5 min; The natural starch and vegetable oil are used in a ratio of 0.24 to 0.38 g of natural starch per 1 ml of vegetable oil; (2) adding water to the starch-oil suspension obtained in step (1), and stirring again at high speed using a stator-rotor disperser to obtain an oil gel; The amount of water added is 20-30% based on the mass of the natural starch.

2. The preparation method according to claim 1, characterized in that The natural starch in step (1) is one or more of corn starch, pea starch, potato starch and tapioca starch.

3. The preparation method according to claim 1, characterized in that The natural starch in step (1) is waxy corn starch.

4. The preparation method according to claim 1, characterized in that The vegetable oil includes one or more of soybean oil, rapeseed oil, palm oil, peanut oil, sesame oil and sunflower oil.

5. The preparation method according to claim 1, characterized in that The vegetable oil in step (1) is soybean oil.

6. The preparation method according to claim 1, characterized in that The natural starch in step (1) is corn starch.

7. The preparation method according to claim 1, characterized in that The high-speed stirring speed of step (1) is 10000-12000 rpm, and the time is 2-3 minutes.

8. The preparation method according to claim 1, characterized in that The high-speed stirring speed of step (1) is 12000 rpm and the time is 3 minutes.

9. The preparation method according to claim 1, characterized in that The ratio of the natural starch to the vegetable oil in step (1) is 0.32-0.38 g of natural starch per 1 ml of vegetable oil.

10. The preparation method according to claim 1, characterized in that The ratio of the natural starch to the vegetable oil in step (1) is 0.32 g of natural starch per 1 ml of vegetable oil.

11. The preparation method according to claim 1, characterized in that The ratio of natural starch to vegetable oil in step (1) is 0.35 g of natural starch per 1 ml of vegetable oil.

12. The preparation method according to claim 1, characterized in that The amount of water added in step (2) is 25% based on the mass of the natural starch.

13. The preparation method according to claim 1, characterized in that The high-speed stirring speed of step (2) is 9000-12000 rpm, and the time is 1-5 min.

14. The preparation method according to claim 1, characterized in that The high-speed stirring speed in step (2) is 12000 rpm and the time is 3 minutes.

15. The natural starch-based oil gel prepared by the preparation method according to any one of claims 1 to 14.

16. Use of the natural starch-based oil gel according to claim 15 in preparing 3D printed food.

17. Use of the natural starch-based oil gel according to claim 15 as a cookie butter, an oil-soluble drug carrier, or a substitute for animal fat products.

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