Solid composition and method for producing the same

Abstract

The present invention provides a solid composition obtained by heating a liquid composition containing starch, which exhibits excellent shape retention and hardness, and a method for efficiently producing such a solid composition. [Solution] A method for producing a solid composition, comprising the following steps (i) and (ii). (i) A step of preparing a liquid composition containing 5% by mass or more of starch and 0.5% by mass or more of insoluble dietary fiber. (ii) A step of heating the liquid composition of (i) to gel it into a solid composition.

Description

[Technical Field]

[0001] The present invention relates to a solid composition obtained by heating a liquid composition containing starch and insoluble dietary fiber to form a solid composition, and to a method for producing the same. [Background technology]

[0002] Conventionally, methods for producing a solid composition by heating a liquid composition containing starch to form a gel include methods using a 3D food printer (Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-026221 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The conventional technology described above had room for improvement in terms of properties such as the shape retention and hardness of the resulting solid composition, as well as the efficiency of manufacturing.

[0005] The present invention has been made in view of the above problems, and aims to provide a solid composition obtained by heating a liquid composition containing starch to form a solid composition that has excellent shape retention and hardness, and a method for efficiently producing such a solid composition. [Means for solving the problem]

[0006] As a result of diligent research, the inventors discovered that by heating a liquid composition containing a predetermined amount or more of insoluble dietary fiber in addition to starch, it is possible to efficiently produce a solid composition with excellent shape retention and hardness, thus completing the present invention.

[0007] In other words, the purpose of this invention relates, for example, to the following: [Item 1] A method for producing a solid composition, comprising the following steps (i) and (ii). (i) A step of preparing a liquid composition containing 5% by mass or more of starch and 0.5% by mass or more of insoluble dietary fiber. (ii) A step of heating the liquid composition of (i) to gel it into a solid composition. [Item 2] The method according to Item 1, wherein the liquid composition has an insoluble dietary fiber content of 1% by mass or more. [Item 3] The method according to item 1 or 2, wherein the starch and / or insoluble dietary fiber of the liquid composition is derived from plants, animals, or fungi. [Clause 4] The method according to any one of claims 1 to 3, wherein the starch and / or insoluble dietary fiber of the liquid composition is at least one plant-derived component selected from the group consisting of cereals, potatoes, legumes, and nuts. [Item 5] The method according to any one of items 1 to 4, wherein the liquid composition further contains 2% by mass or more of protein. [Item 6] The method according to item 5, wherein the protein of the liquid composition is a component derived from a plant, animal, or fungus. [Clause 7] The method according to Claim 5, wherein the protein of the liquid composition is at least one plant-derived component selected from the group consisting of cereals, potatoes, legumes, and nuts. [Item 8] The method according to any one of items 1 to 7, wherein the liquid composition further contains 1% by mass or more of lipids. [Clause 9] The method according to any one of Claims 1 to 8, wherein the liquid composition is acidic. [Item 10] The method according to item 9, wherein the pH of the liquid composition is 6 or less. [Clause 11] The method according to any one of Clauses 1 to 10, wherein between steps (i) and (ii) described above, step (i-2) is included below. (i-2) A step of adding an immiscible medium that does not mix with the liquid composition to the liquid composition prepared in step (i). [Item 12] The liquid composition is hydrophobic, and the immiscible medium is hydrophilic, or The method according to claim 11, wherein the liquid composition is hydrophilic and the immiscible medium is hydrophobic. [Item 13] The method according to item 11 or 12, wherein the heating in step (ii) is the stirring and heating of the liquid composition. [Clause 14] The method according to any one of Clauses 11 to 13, wherein the immiscible medium is a dispersion in which a solid phase containing water-soluble dietary fiber and protein is dispersed in a liquid phase. [Clause 15] The method according to Claim 14, wherein the heating in step (ii) is performed by stirring and heating the liquid composition to gel the liquid composition into a substantially granular form, and the solid phase in the dispersion adheres as a coating layer to the gelled core portion of the liquid composition to form core-shell particles. [Item 16] A solid composition prepared by any one of the methods described in items 1 to 15. [Item 17] A granular solid composition, It comprises a granular core containing starch and insoluble dietary fiber, and a gel-like coating layer containing water-soluble dietary fiber and protein that covers the surface of the core. A solid composition in which the core portion is isolated from the outside by the coating layer. [Item 18] The solid composition according to item 17, wherein the area ratio of void openings to the outer surface of the composition is 10% or more and 30% or less. [Item 19] A solid composition according to item 17 or 18, wherein the hue in the Munsell color system is 0YR to 10YR or 0Y to 5Y. [Item 20] A solid composition according to any one of items 17 to 19, wherein the lightness in the Munsell color system is 9.0 or less. [Item 21] A solid composition according to any one of items 17 to 20, wherein the chroma in the Munsell color system is 4 or higher. [Effects of the Invention]

[0008] The present invention provides a solid composition obtained by heating a liquid composition containing starch to form a solid composition that exhibits excellent shape retention and hardness, as well as a method for efficiently producing such a solid composition. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a flowchart schematically showing an example of the procedure of an embodiment of the method for producing a solid composition, which is an embodiment in which a liquid composition is mixed with an immiscible medium and heated for gelation. [Figure 2] Figure 2 is a diagram schematically showing the three-dimensional shape of the solid composition produced in the Examples. [Mode for Carrying Out the Invention]

[0010] Hereinafter, the present invention will be described in detail with reference to specific embodiments. However, the present invention is not limited to the following embodiments, and can be implemented in any form without departing from the gist of the present invention.

[0011] [Method for producing solid compositions] One aspect of the present invention relates to a method for producing a solid composition, which comprises the following steps (i) and (ii) (hereinafter may be appropriately abbreviated as "the production method of the present invention"). (i) A step of preparing a liquid composition containing starch and insoluble dietary fiber each in a predetermined ratio. (ii) A step of gelling the liquid composition of the above (i) by heating to obtain a solid composition.

[0012] [Preparation of the liquid composition] In step (i), a liquid composition containing starch and insoluble dietary fiber each in a predetermined ratio is prepared.

[0013] According to one aspect, the starch content of the liquid composition is usually 5 mass% or more. Among them, it can be 4 mass% or more, or 3 mass% or more, or 2 mass% or more. By setting the starch content to be equal to or higher than these lower limit values, it is possible to improve the shape retention property and hardness of the obtained solid composition. On the other hand, the upper limit is not limited, but can be, for example, 60 mass% or less, or 50 mass% or less, or 40 mass% or less. If the starch content exceeds these upper limits, processing may become difficult.

[0014] According to one embodiment, the starch in the liquid composition may be selected from, for example, components derived from plants, animals, or fungi. According to one embodiment, the starch in the liquid composition may be at least one plant-derived component selected from the group consisting of, for example, cereals, potatoes, legumes, and nuts.

[0015] According to one embodiment, the insoluble dietary fiber content of the liquid composition is usually 0.5% by mass or more. In particular, it can be 0.8% by mass or more, 1.0% by mass or more, or 1.2% by mass or more. By setting the insoluble dietary fiber content above these lower limits, it is possible to improve the shape retention and hardness of the resulting solid composition. On the other hand, there is no upper limit, but it can be, for example, 30% by mass or less, 20% by mass or less, or 15% by mass or less. If the insoluble dietary fiber content exceeds these upper limits, processing may become difficult.

[0016] According to one embodiment, the insoluble dietary fiber of the liquid composition can be selected from, for example, components derived from plants, animals, or fungi. According to one embodiment, the insoluble dietary fiber of the liquid composition may be at least one plant-derived component selected from the group consisting of, for example, cereals, potatoes, legumes, and nuts.

[0017] In one embodiment, it is preferable that the liquid composition further contains protein. If the liquid composition contains protein, the amount is not particularly limited, but in one embodiment, the lower limit can usually be 2.0% by mass or more, or 2.2% by mass or more, or 2.5% by mass or more. By setting the protein content above these lower limits, moldability may be improved. On the other hand, the upper limit is also not limited, but can be, for example, 10.0% by mass or less, or 8.0% by mass or less, or 6.0% by mass or less. If the protein content exceeds these upper limits, processing may become difficult.

[0018] According to one embodiment, the protein of the liquid composition can be selected from, for example, components derived from plants, animals, or fungi. According to one embodiment, the protein of the liquid composition may be at least one plant-derived component selected from the group consisting of, for example, cereals, potatoes, legumes, and nuts.

[0019] In one embodiment, the liquid composition preferably further contains lipids. If the liquid composition contains lipids, the amount is not particularly limited, but in one embodiment, the lower limit can usually be 1.0% by mass or more, 1.5% by mass or more, or 2.0% by mass or more. The taste may be improved by setting the lipid content above these lower limits. On the other hand, the upper limit is also not limited, but can be, for example, 30% by mass or less, 20% by mass or less, or 15% by mass or less. Processing may become difficult if the lipid content exceeds these upper limits.

[0020] In one embodiment of the liquid composition, it is preferable that the liquid composition is acidic. In one embodiment, the pH of the liquid composition is not limited, but can usually be 7.0 or less, or 6.0 or less, or 5.0 or less. Although the principle is unclear, by setting the pH of the liquid composition below these upper limits, it may be possible to promote gelation of the liquid composition by making it easier for proteins to denature. Furthermore, in particular, in embodiments in which the liquid composition described later is mixed with an immiscible medium and heated to gel, the proteins in the liquid composition become positively charged and the starch becomes negatively charged, and the proteins and starch move onto the surface of the particles, which may contribute to further improvement in the shape retention and hardness of the resulting solid composition. On the other hand, the lower limit of the pH of the liquid composition is not limited, but can be, for example, 1.0 or more.

[0021] According to one embodiment, the liquid composition may further contain a pigment. When a pigment is used, it is preferable to use an edible pigment. The edible pigment may be derived from food or be a food additive, as long as it does not impair the effects of the present invention.

[0022] Examples of pigments include the following: Orange Capsicum pigment, annatto pigment, turmeric pigment, Food Yellow No. 5 Red Red cabbage pigment, red radish pigment, purple sweet potato pigment, purple carrot pigment, elderberry pigment, red yeast rice pigment, gardenia red pigment, cochineal pigment, lac pigment, red beet pigment, grape skin pigment, Amaranth (Food Red No. 2), Erythrosine (Red No. 3), Allura Red AC (Red No. 40), New Coccine (Red No. 102), Phloxine (Red No. 104), Rose Bengal (Red No. 105), Acid Red (Red No. 106) Yellow Palm oil carotene, β-carotene, riboflavin, safflower yellow pigment, gardenia yellow pigment, marigold pigment, tartrazine (Food Yellow No. 4) • Brown tones Cocoa pigment Blue Gardenia blue pigment, spirulina blue pigment, Brilliant Blue FCF (Blue No. 1), indigo carmine (Blue No. 2) Black vegetable charcoal pigment

[0023] When using a pigment in the liquid composition, only one type of pigment may be used, or two or more types of pigments may be used in combination. By mixing two or more of the above pigments in any proportion, a desired color can be created. For example, it is possible to create a green pigment by mixing safflower yellow pigment and gardenia blue pigment.

[0024] When using a dye in the liquid composition, in the method of heating and gelling the liquid composition with a laser, as described later, it is desirable to use a dye that absorbs at the wavelength of the laser light used. For example, when using light with a wavelength of 450 nm (blue) as the laser light, the absorbance of food dyes at this wavelength is 0.006 [abs] for Blue No. 1, 0.353 [abs] for Yellow No. 4, and 0.159 [abs] for Red No. 102. In this case, if Blue No. 1 is added to the mixture and irradiated with laser light, there is a possibility that insufficient energy will be absorbed to gelatinize the swollen starch granules. On the other hand, if Red No. 102 or Yellow No. 4 is added to the mixture and irradiated with laser light, it is thought that the swollen starch granules will gelatinize and gelatinized starch will be formed, and sufficient energy will be absorbed for the gelatinized starch granules to gel. In particular, since it is desirable from a safety standpoint to use as little food dye as possible as an additive, it is considered preferable to use Yellow No. 4, whose absorbance spectrum peak is close to the wavelength of the blue laser light.

[0025] When a pigment is used in the liquid composition, there are no particular restrictions on the pigment content in the liquid composition, but it is preferable that the pigment is contained in the liquid composition at a concentration of 0.001% to 0.5% by mass. It is believed that the molding accuracy of food products with three-dimensional shapes is better when the pigment concentration is higher. On the other hand, if the pigment concentration is very high, it is possible that the molded food product may char (brown). This phenomenon can be used, for example, when molding parts in which you want to change the texture or flavor, to use a mixture containing a higher concentration of pigment than other parts.

[0026] Furthermore, if the liquid composition contains a high concentration of dye, it is conceivable that the layer of starch being fabricated will be thinner when the mixture is irradiated with laser light under the same conditions compared to when the concentration of dye in the liquid composition is low. This is because the higher the concentration of dye in the liquid composition, the more easily the laser light is absorbed by the mixture, and the laser light irradiated from above the mixture is absorbed in the shallow part of the mixture and does not reach the deeper part of the liquid composition. Of course, it is also possible to adjust the thickness of the layer of starch being fabricated by adjusting the concentration of dye in the liquid composition using this phenomenon.

[0027] It should be noted that commercially available food colorings are traded in powder form, and because the concentration of the coloring alone is too high, the volume is increased with polysaccharides such as dextrin. When this is dissolved in water, the polysaccharides such as dextrin may act as surfactants or dispersion stabilizers, and may exert their effects in the mixed solution. Here, it is important to note that if commercially available food coloring (with a bulking agent) is added to an aqueous dispersion of starch powder, the polysaccharides used for bulking may affect the dispersion state of the starch powder, the rate of starch swelling upon heating, and the speed of bonding between swollen starch particles. Furthermore, the dispersion state of the coloring is expected to differ between an aqueous solution of the coloring alone and an aqueous solution containing the coloring and a bulking agent. It is also important to note that this may lead to changes in the absorption spectrum of the coloring. Specifically, if the coloring in water is dispersed individually at the molecular level, only the photoreaction process of the individual coloring molecules needs to be considered for light absorption. On the other hand, if the pigment molecules are dispersed in an aggregated state due to the presence of a bulking agent, the efficiency of light absorption may change as absorbed light causes energy transfer to other pigments.

[0028] In one embodiment, the absorbance of the liquid composition at a wavelength of 420 nm is preferably 0.1 or higher, or 0.2 or higher, or 0.3 or higher. By setting the absorbance of the liquid composition at a wavelength of 420 nm to be above these lower limits, efficient heating by laser may be possible. The method for adjusting the absorbance of the liquid composition at a wavelength of 420 nm to be above the above lower limit is not particularly limited, but it can be adjusted, for example, by including a predetermined amount of the above dye in the liquid composition. On the other hand, the upper limit is also not limited, but it can be, for example, 5.0 or lower, or 4.0 or lower.

[0029] In one embodiment, the liquid composition preferably satisfies the following characteristics defined in the Munsell color system (JIS Z 8721). These characteristics are not limited, but are particularly suitable in embodiments in which the liquid composition is heated and gelled by a laser.

[0030] According to one embodiment, the liquid composition is preferred because its hue, as defined in the Munsell color system (JIS Z 8721), falls within a predetermined range, making it particularly suitable for use with a laser 3D food printer (FP). Although the principle is unclear, it is believed that a liquid composition having a specific hue is more likely to retain its shape when left at room temperature due to the laser light when used with a laser 3D food printer. It is particularly preferred when using blue laser light, as this results in a liquid composition that easily retains its shape when left at room temperature. In other words, a composition within this hue range indicates that the oils and fats having a specific color tone are of a quality that have not been significantly decomposed. Therefore, it is believed that a composition within a predetermined hue range is less likely to produce a hay-like odor. Specifically, it is preferable that the final composition has a hue of 0YR to 10YR (0Y) or 0Y to 5Y. Among these, 0YR to 10YR is preferred, 2.5YR to 10YR is preferred, 2.5YR to 7.5YR is preferred, and 5.0YR to 7.5YR is particularly preferred. Furthermore, the dried edible plants in the composition (especially those with a yellowish hue are preferred, and the edible plants may be any of vegetables, legumes, or plants of the Apiaceae family, and more preferably paprika, peas (especially yellow peas), carrots, celery, parsley, Japanese parsley, and cilantro, and it is even more preferable that paprika, yellow peas, and carrots have the aforementioned hue.

[0031] In one embodiment, the liquid composition is more preferable because its lightness, as defined in the Munsell color system (JIS Z 8721), falls within a predetermined range, thereby suppressing the generation of hay odor during storage. That is, a composition within this lightness range indicates that the oils and fats having a specific hue are of a quality that have not been significantly decomposed. Specifically, the lightness of the final composition is preferably less than 9.0, and although the lower limit is not particularly defined, it is preferable that it be in the range of 1.0 or higher. More specifically, the upper limit is preferably less than 9.0, and particularly preferably less than 8.5. On the other hand, the lower limit is not particularly limited, but it is preferably 1.0 or higher, or 3.0 or higher, and particularly preferably 5.0 or higher. Furthermore, it is even more preferable that the dried edible plants in the composition (especially Apiaceae plants, more preferably carrots, celery, parsley, water dropwort, and cilantro, especially carrots) are within the lightness range in addition to being within the hue range.

[0032] In one embodiment, the liquid composition is more preferable because the saturation defined in the Munsell color system (JIS Z 8721) is within a predetermined range, thereby suppressing the generation of hay odor during storage. That is, a composition within this saturation range indicates that the oils and fats having a specific hue are of a quality that have not been significantly decomposed. Specifically, the saturation of the final composition is preferably in the range of greater than 4 and less than or equal to 14. More specifically, the lower limit is preferably greater than 4. Among these, greater than 5, even more preferably greater than 6, and especially greater than 7. On the other hand, the upper limit is not particularly limited, but may be 14 or less. Furthermore, it is more preferable that both the lightness and saturation are within the predetermined range, as this makes it easier to suppress the generation of hay odor during storage. It is even more preferable that the dried edible plants in the composition (especially Apiaceae plants, more preferably carrots, celery, parsley, water dropwort, and cilantro, especially carrots) are within the saturation range in addition to being within the hue range, and it is particularly preferable that both the lightness and saturation are within the predetermined range.

[0033] In the Munsell color system, the Munsell hue circle uses RYGBP as the five main hues, with YR, GY, BG, PB, and RP added between them to form a total of 10 hues. These hues are arranged in a circular, clockwise direction, and the intervals between them are divided into 10 equal steps, with markings indicating 1Y to 10Y, thus representing the entire hue range. In this invention, when describing the range of hues, unless otherwise specified, the range is shown in the table in Figure 1 in a clockwise direction. The boundary between the main hues, for example, the boundary between YR and Y, can be expressed as 10YR or 0Y. For example, 0YR to 10YR or 0Y to 5Y represents the range of hues that changes continuously from 0YR → 10YR (or 0Y) → 5Y. In the Munsell color system, lightness is defined as 0 for ideal black with a reflectance of 0 and 10 for ideal white with perfect reflection.

[0034] [Heating and gelling of liquid compositions] In step (ii), the liquid composition prepared in step (i) is heated to gel. In this step, the liquid composition solidifies through gelation, forming a solid composition.

[0035] The heating temperature of the liquid composition is not particularly limited, but in one embodiment, the lower limit of the average temperature of the composition during heating can be set to 70°C or higher, 75°C or higher, 80°C or higher, or 85°C or higher. Setting the heating temperature above these lower limits may allow the composition to be processed smoothly. On the other hand, the upper limit is also not limited, but in one embodiment, it can be, for example, 300°C or lower, 250°C or lower, 200°C or lower, 150°C or lower, 100°C or lower, 95°C or lower, or 92°C or lower. If the heating temperature exceeds these upper limits, the composition may burn. In particular, when producing a granular (for example, with a diameter of 30 mm or less, and although the lower limit is not particularly limited, with a diameter of 1 mm or more) solid composition by adding the liquid composition to an unsaturated medium, the composition may be heated so that its core temperature satisfies the above temperature requirements for the heating time described later (for example, 1 minute or more, 2 minutes or more, or 3 minutes or more).

[0036] The heating time of the liquid composition is not particularly limited, but in one embodiment, the lower limit can usually be 1 minute or more, 3 minutes or more, or 5 minutes or more. By setting the heating time to be above these lower limits, the composition may be able to be processed smoothly. On the other hand, the upper limit is also not limited, but can be, for example, 50 minutes or less, 30 minutes or less, or 20 minutes or less. If the heating time exceeds these upper limits, too much moisture may be removed from the solid composition, causing it to harden.

[0037] The method for heating the liquid composition is not particularly limited. Examples include heating by a heater, heating by a hot water bath or oil bath, heating by laser irradiation, heating by heat conduction from a metal, oven heating, far-infrared heating, microwave heating, and the like.

[0038] After heating and gelling the liquid composition, a solid composition can usually be obtained by cooling the gelled composition. The cooling temperature is not particularly limited, but according to one embodiment, its upper limit can usually be 60°C or higher, 50°C or lower, or 40°C or lower.

[0039] [An embodiment of mixing a liquid composition with an immiscible medium and then heating and gelling it] One embodiment of the manufacturing method of the present invention is to add the liquid composition prepared in step (i) above to an immiscible medium that does not mix with the liquid composition, and to subject the resulting mixture to heating and gelling in step (ii).

[0040] That is, according to one embodiment, the following step (i-2) is included between step (i) and step (ii) above. (i-2) A step of adding the liquid composition prepared in step (i) above to an immiscible medium that does not mix with the liquid composition.

[0041] As the immiscible medium, liquids with different hydrophilicity levels to the extent that they form an interface with the liquid composition at room temperature (e.g., 20°C) and atmospheric pressure (e.g., 1 atm) can be used. Specifically, when an aqueous solvent (e.g., a solvent containing 50% or more water by mass) is used as the immiscible medium, an oil-based solvent (e.g., a solvent containing 50% or more oil by mass) with low polarity to the extent that it forms an interface with the liquid composition can be used. That is, according to one embodiment, the liquid composition is hydrophobic (oil-based medium) and the immiscible medium is hydrophilic (aqueous medium). On the other hand, when an oil-based solvent is used as the immiscible medium, an aqueous solvent with high polarity to the extent that it forms an interface with the liquid composition can be used. That is, according to one embodiment, the liquid composition is hydrophilic (aqueous medium) and the immiscible medium is hydrophobic (oil-based medium). When using a suspension of dried material such as microbial cells in the liquid composition, it is preferable to use it suspended in an oil-based solvent.

[0042] According to one embodiment, an aqueous solvent or an oil-based solvent can be used as the immiscible medium. However, according to another embodiment, it is preferable to use a dispersion in which a solid phase containing water-soluble dietary fiber and protein is dispersed in a liquid phase as the immiscible medium. By using such a dispersion as the immiscible medium, core-shell particles are formed in which the solid phase in the dispersion adheres as a shell around a gelled core of the liquid composition, which may improve the shape retention and hardness of the resulting solid composition. That is, according to one embodiment, the heating in step (ii) includes stirring and heating the liquid composition to gel the liquid composition into a substantially granular form, and forming core-shell particles in which the solid phase in the dispersion adheres as a shell around a gelled core of the liquid composition.

[0043] A more specific example of the procedure in this embodiment will be described with reference to Figure 1. However, the specific procedure in this embodiment is not limited in any way to the procedure shown in Figure 1.

[0044] Figure 1 is a schematic flowchart illustrating one example of a procedure for manufacturing a solid composition, in which a liquid composition is mixed with an immiscible medium and then heated and gelled. In this figure, it is assumed that a dispersion containing a solid phase with water-soluble dietary fiber and protein is dispersed in a liquid phase as the immiscible medium, but the method is not limited to this, and it is also possible to use an aqueous solvent or an oil-based solvent without a solid phase.

[0045] First, as shown in Figure 1A, the immiscible medium 1 is heated by a heater H while being stirred by a stirring blade P. Next, as shown in Figure 1B, the pre-prepared liquid composition 2 is added dropwise while the immiscible medium 1 is being heated and stirred. Here, the liquid composition 2 may be preheated. Subsequently, as shown in Figure 1C, the liquid composition 2 gels upon heating and solidifies into particulate matter in the immiscible medium 1. Then, as shown in Figure 1D, the immiscible medium 1 is cooled, forming a core-shell-shaped solid composition 3 in which the solid phase in the immiscible medium adheres as a coating layer 3B around the particulate core portion 3A formed by the gelling and solidification of the liquid composition.

[0046] [Modes using lasers] In the manufacturing method of the present invention, a method may be used in which a portion of the liquid composition is gelled by irradiating it with a laser. In this method, by irradiating a mixture of starch powder and water with laser light, the starch granules of the starch powder swell with water to form swollen starch granules, the swollen starch granules gelatinize to form gelled starch, and the gelled starch granules gel to obtain gelled starch.

[0047] The laser light used in this embodiment may have various wavelengths, including those in the infrared, ultraviolet, and visible light regions. In this invention, the laser light source that emits the laser light can be a visible light laser or an infrared laser, but the following points should be considered.

[0048] • About the visible light absorption of starch When a visible light laser is shone onto a dispersion of starch particles (assuming here that it does not contain any dyes), the energy of the irradiated laser light is converted into thermal energy when the light is absorbed by the starch particles. However, since starch does not absorb light in the visible light region, most of the irradiated light is scattered at the surface of the starch particles, and it is thought that the efficiency of the light energy absorbed by the starch particles and converted into thermal energy is not high. The fact that a solution with dispersed starch particles appears white suggests that the light is undergoing elastic scattering without energy absorption at the surface of the starch particles. The very fact that a dispersion of starch particles appears white means that the starch particles do not absorb light easily.

[0049] • About water's absorption of visible light Water is transparent to visible light and does not absorb light. Therefore, it is unlikely that the efficiency of converting irradiated visible light laser energy into thermal energy to raise the water temperature is high. Based on these considerations, in order to locally raise the temperature of a dispersion of starch particles in water without dye by irradiating it with a visible light laser, it is considered necessary to irradiate it with enough laser light to supply sufficient energy.

[0050] • About the infrared light absorption of water When using an infrared laser with an emission wavelength in the infrared region, such as a carbon dioxide laser, it is theoretically possible to raise the temperature of an aqueous solution by irradiating water with an infrared laser, because water absorbs infrared light. However, generally, water absorbs only a small amount of infrared light; for example, more than 70-90% of infrared light penetrates 1 mm thick water. Because so-called light penetration occurs (specifically, light penetrates to a depth of several tens of millimeters), it is expected that achieving high resolution in the Z-axis direction will be difficult when using infrared lasers in 3D printers.

[0051] Furthermore, when an infrared laser is irradiated onto a mixture of cloudy starch powder and water, elastic scattering occurs on the surface of the starch particles. The multiple scattering of light prevents it from passing linearly through the sample, causing it to propagate diffusely through repeated random scattering. The diffusion region at that time is thought to range from several hundred micrometers to tens of millimeters. This can also be a factor that lowers the resolution of 3D printers.

[0052] On the other hand, if the required spatial resolution is around several hundred micrometers, it is possible to optically confine the area illuminated by the infrared laser to around several hundred micrometers by using an objective lens, a pinhole, or an optical fiber. In other words, in this invention, it is possible to design a 3D printer with a spatial resolution of around several hundred micrometers using an infrared laser as the light source.

[0053] Industrially, carbon dioxide lasers are widely used as light sources for laser cutters that cut solid materials by heating, melting, or burning. In this invention, a mixture of starch powder and water is irradiated with a carbon dioxide laser to gel the starch granules. By continuing to irradiate the solidified portion with laser light and heating it, this portion carbonizes and turns brown, which allows for more efficient light absorption and further accelerates the carbonization of the starch. The change to brown is thought to mean that a chemical change in the carbon present in the starch causes a change in the molecular structure of the starch, affecting the absorption spectrum. Utilizing this phenomenon, it is also possible to use a carbon dioxide laser for post-processing of food products after the powder has been gelled in this invention.

[0054] • Regarding the use of pigments In this invention, a visible light laser can be used instead of a carbon dioxide laser. When using a visible light laser, it is preferable to use a dye, particularly a dye that absorbs at the wavelength of the visible light laser, as a means to efficiently convert light into thermal energy in order to raise the temperature of the starch particle dispersion. When using a dye, it is possible to convert light energy into thermal energy with any efficiency by selecting the dye. Therefore, in this case, light of various wavelengths can be used.

[0055] • Availability of visible light lasers In this invention, a laser light source with an output of 1W to 100W can be suitably used to emit laser light. Visible light lasers in the tens of mW to hundreds of mW class can be purchased for several thousand to tens of thousands of yen, making them easily selectable for creating consumer 3D printers.

[0056] Regarding scanning speed from the perspective of gelation In this invention, by irradiating a portion of a mixture of starch powder and water with laser light, the starch granules of the starch powder swell with the water to form swollen starch granules, these swollen starch granules gelatinize to form gelled starch, and the gelled starch granules then gel to obtain gelled starch.

[0057] When the local temperature of an aqueous solution is increased by laser irradiation, swelling of starch particles present in the water and dissolution of amylose contained in the starch are induced. In the subsequent process, contact between the swollen starch particles and the formation of microcrystals that occur after the dissolution of amylose, which bridges the starch particles, promote the gelatinization of the starch particles. This increases the viscosity of the dispersion, and when crystal formation reaches a threshold, gelation occurs, resulting in elasticity. Once the temperature state in which swelling begins is reached, the swelling and amylose dissolution proceed rapidly. Therefore, it is thought that local swelling of starch particles can be sufficiently induced if the heating process by laser irradiation takes only a few milliseconds.

[0058] In the present invention, in general, the spot diameter of the laser beam is preferably 0.01 mm to 1 mm. Further, when the step of irradiating the laser beam includes a step of scanning the laser beam according to a predetermined pattern, the scanning speed is preferably 0.5 mm / s to 100 mm / s. Specific examples of numerical estimation are described below.

[0059] ·Example 1. Case where the spot diameter is 0.1 mm and the scanning speed is 100 mm / s When the laser scanning speed of the 3D printer is set to 100 mm / s and the spot diameter of the laser irradiated at this time is set to 0.1 mm, the time during which the 0.1 mm spot is exposed to light is (0.1×2) mm ÷ 100 mm / s = 2 ms. The diffusion coefficient of water molecules in the normal temperature range is approximately 10 -9 m 2 / s, At an elapsed time of 1 ms, the maximum movement distance of water molecules is √(10 -9 m 2 / ×1 ms)=10 -6 m=1 μm At an elapsed time of 100 ms, the maximum movement distance of water molecules is √(10 -9 m 2 / ×100 ms)=10 -5 m=10 μm At an elapsed time of 10 s, the maximum movement distance of water molecules is √(10 -9 m 2 / ×10 s)=10 -4 m=0.1 mm Thus, after 10 s, the water molecules that were in the 0.1 mm spot return to the original water temperature due to diffusion. In reality, it is considered that the temperature returns within several seconds.

[0060] The volume when the spot diameter is 0.1 mm is 4π(0.01 / 2 cm) 3 / 3 is equivalent to approximately 520 pL (picoliters). The thermal energy required to raise the temperature of 520 picoliters of water by 1°C is 0.5 microcalories, and to raise it by 100°C, 50 microcalories, or 0.05 millicalories, of energy is required. This energy is equivalent to 0.2 mJ, so to generate 0.2 mJ of heat in 2 ms, a laser light source of 0.2 mJ / 2 ms = 0.1 W would be sufficient.

[0061] Example 2: When the spot diameter is 0.2 mm and the scanning speed is 5 mm / s If the laser scanning speed of the 3D printer is 5 mm / s and the spot diameter of the laser being emitted is 0.2 mm, then the time that light hits the 0.2 mm spot is (0.2 × 2) mm ÷ 5 mm / s = 80 ms.

[0062] The volume for a spot diameter of 0.2 mm is approximately 4π (0.01 cm³). 3 / 3 is equivalent to approximately 4190 pL (picoliters). The thermal energy required to raise the temperature of approximately 4 picoliters of water by 1°C is 42 microcalories, and to raise it by 100°C, 400 microcalories, or 0.4 millicalories, of energy is required. This energy is equivalent to 1.6 mJ, so to generate 1.6 mJ of heat in 10 ms, assuming that all the irradiated light energy is converted into heat, a laser light source of 1.6 mJ / 80 ms = 0.2 W would be sufficient. For example, if a 5 W class laser is used, even if the thermal conversion efficiency is around 20%, the power output will be around 1 W, which is considered sufficient to heat the object.

[0063] • Scanning speed and the elastic modulus of the printed object It is thought that the higher the scanning speed, that is, the lower the amount of laser light irradiated per unit area, the lower the elastic modulus of the shaped food product will be. This is because a lower amount of light per unit area results in a lower heating temperature for the starch, making gelatinization more difficult, and consequently, a lower elastic modulus.

[0064] (Regarding the diversification of stereolithography 3D printers) In the present invention, the step of irradiating with laser light may be a step of scanning the laser light according to a predetermined pattern, but is not limited to this. One method of stereolithography is stereolithography (SLA), which uses a galvanometer mirror or similar device to scan a linear beam of laser light. Another method involves introducing laser light into a liquid through an optical fiber ("optical fiber method").

[0065] More recently, a method called DLP (digital light processing), which uses light from a projector, has become more widely used because it can write across a surface, making it significantly faster than laser scanning. In this method, a MEMS device made of hundreds of thousands of tiny micro-mirrors enables projection.

[0066] More recently, there is a method called the LCD method, which uses UV light from an LED to react with light that has passed through a liquid crystal filter attached to the bottom of the bathtub. This LCD method can achieve high spatial resolution similar to that of laser light, even without using a laser beam that travels in a straight line, by using the size and surface density of the LCD dots. In this invention, any of these methods can be employed to the extent that the effects of the present invention can be obtained.

[0067] <Food three-dimensional printing equipment> Figure 2 is a schematic perspective view showing the configuration of a food three-dimensional molding apparatus (3D printer) used in this embodiment (an embodiment in which a liquid composition is heated and gelled with a laser). The apparatus shown here is an example of an apparatus employing the "bathtub method" among the three methods described above. The apparatus of the present invention includes a mixture receiving means, such as a container 20, which receives the mixture from a mixture providing means (not shown) for providing a mixture of starch powder and water.

[0068] A portion of the mixture contained in container 20 is irradiated with laser light from a laser module 10 equipped with a laser light source. As a result, the starch granules of the starch powder in container 20 swell with water to form swollen starch granules, these swollen starch granules gelatinize to form gelled starch, and the gelled starch granules then gel, resulting in gelled starch. Container 20 is placed on a movable platen 21.

[0069] The relative positions of the container 20 and the laser module 10 in the X, Y, and Z axes are controlled by relative position control means so that laser light from the laser module 10 can be irradiated onto predetermined positions of the mixture in the container 20 according to a predetermined pattern based on the three-dimensional shape of the food. Specifically, the relative positions of the container 20 and the laser module 10 can be controlled by driving pulleys and belts, or nuts and arms, etc., with a stepping motor according to information based on a predetermined pattern.

[0070] In the apparatus of the present invention, the laser module 10 irradiates the mixture with laser light under predetermined irradiation conditions according to a predetermined pattern based on the three-dimensional shape of the food, in response to control by an irradiation control means (not shown).

[0071] [Solid composition] One aspect of the present invention relates to a solid composition manufactured by the method of any of the above aspects. The type of solid composition is not particularly limited, but is preferably a food product. The type of food product is not particularly limited, but examples include various food structures mainly composed of starch, such as sushi rice, sushi rice substitutes, vegetable substitutes, meat substitutes, fish substitutes, confectionery (e.g., baked goods, especially cakes), and nutritional supplements (e.g., nutrition bars). It can also be used as an edible capsule-shaped coating material for secreting active ingredients from moisture.

[0072] One aspect of the present invention relates to a granular solid composition comprising a granular core containing starch and insoluble dietary fiber, and a gel-like coating layer containing water-soluble dietary fiber and protein that covers the surface of the core, wherein the core is isolated from the outside by the coating layer.

[0073] One aspect of the present invention relates to a lattice-shaped solid composition containing predetermined amounts or more of starch, insoluble dietary fiber, and protein, and having a porosity of predetermined amounts or more relative to the bulk volume of the composition. In particular, when the solid composition is a food structure mainly composed of starch, such as a substitute for sushi rice, it is preferable that the porosity of the walls of the solid composition be adjusted to a certain ratio so that the texture of the composition is similar to that of food structures such as sushi rice. In one aspect, the porosity of the walls of the solid composition can be, for example, 40% or more and 80% or less. Specifically, the lower limit of the porosity of the solid composition can be 40% or more, or 45% or more, or 50% or more, or 55% or more. This may result in a composition with a texture similar to that of food structures such as sushi rice. Furthermore, there is no particular upper limit to the porosity of the solid composition, but from the viewpoint of ease of three-dimensional molding, the upper limit may be 80% or less, or 75% or less, or 70% or less, or 68% or less. In this specification, the "porosity" of a composition refers to the ratio of the volume of space communicating with the outside world to the volume of the smallest imaginary rectangular parallelepiped inscribed within the composition.

[0074] According to one embodiment, the above-mentioned lattice-shaped solid composition preferably has a specific wall structure. Specifically, it is preferable that the wall thickness of the solid composition gradually decreases toward the intersections where the walls of the solid composition are connected, to 70% or less, 60% or less, or 50% or less of the average wall thickness of the entire solid composition. This makes it easier to quickly remove any remaining liquid composition during molding, and is preferable for use when molding with a 3D printer. The lower limit is not particularly limited, but from the viewpoint of maintaining strength, it is preferable to set it to 20% or more, 30% or more, or 40% or more.

[0075] In one embodiment, adjusting the area ratio of void openings to the outer surface of the solid composition to a certain ratio is preferable because it results in a composition with a texture similar to sushi rice. Specifically, it is preferable that the area ratio of void openings to the outer surface of the composition is 10% or more and 30% or less. More specifically, it is preferable that the lower limit is 10% or more, or 12% or more, or 14% or more, as this brings the texture closer to sushi rice. On the other hand, there is no particular upper limit, but from the viewpoint of ease of three-dimensional molding, it can be, for example, 30% or less, or 28% or less, or 26% or less, or 24% or less, or 22% or less, or 20% or less. In particular, it is preferable from the viewpoint of strength that the void shape is hollowed out in a cylindrical shape.

[0076] According to one embodiment, the solid composition preferably satisfies the following characteristics as defined in the Munsell color system (JIS Z 8721).

[0077] In one embodiment, it is preferable that the solid composition has a hue within a predetermined range as defined in the Munsell color system (JIS Z 8721). Specifically, it is preferable that the hue of the final composition is 0YR to 10YR (0Y) or 0Y to 5Y. In particular, it is preferable that it is 0YR to 10YR, 2.5YR to 10YR, 2.5YR to 7.5YR, and especially 5.0YR to 7.5YR.

[0078] In one embodiment, it is preferable that the solid composition has a lightness within a predetermined range as defined in the Munsell color system (JIS Z 8721). Specifically, the lightness of the final composition is preferably less than 9.0, and although the lower limit is not particularly specified, it is preferably in the range of 1.0 or higher. More specifically, the upper limit is preferably less than 9.0, and particularly preferably less than 8.5. On the other hand, although the lower limit is not particularly limited, it is preferably 1.0 or higher, or 3.0 or higher, and particularly preferably 5.0 or higher.

[0079] According to one embodiment, it is preferable that the solid composition has a chroma within a predetermined range as defined in the Munsell color system (JIS Z 8721). Specifically, it is preferable that the chroma of the final composition be in the range of greater than 4 and less than or equal to 14. More specifically, it is preferable that the lower limit is greater than 4. Among these, it is preferable that it be greater than 5, even more preferably greater than 6, and especially greater than 7. On the other hand, the upper limit is not particularly limited, but may be 14 or less. [Examples]

[0080] The present invention will be described in more detail below with reference to examples, but these examples are merely illustrative examples for explanatory purposes, and the present invention is not limited in any sense to these examples.

[0081] • Preparation of liquid composition: Liquid compositions for each test example and comparative example were prepared by dispersing the dispersed phases shown in Table 1 in the media shown in Table 1, each containing starch, insoluble dietary fiber, protein, lipids, sugars, and water in the amounts shown in Table 1.

[0082] • Preparation of immiscible media: Furthermore, the liquid oils and fats shown in Table 2 (salad oil manufactured by Nisshin Oillio Co., Ltd.) were used as they were, or by dispersing the dispersed particles shown in Table 2, to form dispersions containing insoluble dietary fiber and protein in the amounts shown in Table 2, respectively, which were used as immiscible media for each test example and comparative example.

[0083] • Manufacturing of solid compositions: The immiscible media for each of the above test examples and comparative examples were heated while being stirred. The liquid compositions for each of the above test examples and comparative examples were poured into the heated immiscible media, and the liquid compositions were gelled by heating so that the core temperature of the granular solid compositions reached 90°C or higher and was maintained at that temperature for 3 minutes, thereby producing the particulate solid compositions for each of the test examples and comparative examples.

[0084] The manufactured solid composition was a capsule-like granular solid composition in which the medium of the liquid composition was localized internally and the dispersed phase was localized on the surface. Although the principle is not clear, it is thought that the bipolar dispersed phase localized at the interface between the hydrophilic liquid composition and the hydrophobic unsaturated medium, and then localized on the surface of the solid composition and solidified upon heating. Furthermore, in compositions in which the dispersed phase was mixed with the unsaturated medium, a tendency for the shape of the granular solid composition to become uniform was observed. This is thought to be because the dispersed phase in the unsaturated medium localized at the interface between the hydrophilic liquid composition and the hydrophobic unsaturated medium, stabilizing the shape of the solid composition.

[0085] Furthermore, when the pH of the liquid composition is adjusted to 5.0 or below by adding acetic acid, a tendency for the solidification rate to increase is observed. Although the principle is unknown, it is possible that lowering the pH of the liquid composition makes it easier for proteins to denature, thereby promoting the gelation of the liquid composition.

[0086] ·evaluation: The solid compositions of each test example and comparative example obtained through the above procedure were evaluated for the following criteria regarding "shape retention," "hardness," and "solidification rate." The evaluation results are shown in Table 3.

[0087] • Evaluation criteria for "shape retention": The shape retention of the obtained solid composition was evaluated on a four-point scale as follows. 4: The composition is self-supporting and no change in shape is observed, which is highly desirable. 3: The composition is self-supporting and shows almost no change in shape, which is preferable. 2: The composition is self-supporting and its shape changes within an acceptable range. 1: The composition is not self-supporting and undergoes significant shape changes, which is undesirable.

[0088] • Criteria for evaluating "firmness": The hardness of the obtained solid composition was evaluated on a four-point scale as follows. 4: The composition has a strong firmness, and the texture is very pleasant. 3: The composition has a good firmness, and the texture is somewhat pleasant. 2: The composition has a noticeable firmness, and the texture is within an acceptable range. 1: The composition lacks firmness, resulting in an undesirable texture.

[0089] • Criteria for evaluating "coagulation rate": The solidification rate during the production of solid compositions was evaluated in the following two stages. Fast: The liquid composition solidifies as soon as it is added to the unsaturated medium, which is preferable. Slow: The liquid composition solidifies after some time has passed since being added to the unsaturated medium, which is undesirable.

[0090] In addition, for some cases, the findings obtained from observations are noted in the comments section of Table 3.

[0091] [Table 1]

[0092] [Table 2]

[0093] [Table 3] [Industrial applicability]

[0094] This invention can be widely applied to the field of food processing, particularly the food tech field, and its utility is extremely high. [Explanation of Symbols]

[0095] 1 Immiscible medium (dispersion) 2. Liquid composition 3 Solid composition 3A Core 3B Covering layer H heater P (P) Agitator blade

Claims

1. A method for producing a solid composition, comprising the following steps (i) and (ii). (i) A step of preparing a liquid composition containing 5% by mass or more of starch and 0.5% by mass or more of insoluble dietary fiber. (ii) A step of heating the liquid composition of (i) to gel it into a solid composition.

2. The method according to claim 1, wherein the insoluble dietary fiber content of the liquid composition is 1% by mass or more.

3. The method according to claim 1, wherein the starch and / or insoluble dietary fiber of the liquid composition is a component derived from plants, animals, or fungi.

4. The method according to claim 1, wherein the starch and / or insoluble dietary fiber of the liquid composition is at least one plant-derived component selected from the group consisting of cereals, potatoes, legumes, and nuts.

5. The method according to claim 1, wherein the liquid composition further contains 2% by mass or more of protein.

6. The method according to claim 5, wherein the protein in the liquid composition is a component derived from a plant, animal, or fungus.

7. The method according to claim 5, wherein the protein of the liquid composition is at least one plant-derived component selected from the group consisting of cereals, potatoes, legumes, and nuts.

8. The method according to claim 1, wherein the liquid composition further contains 1% by mass or more of lipids.

9. The method according to claim 1, wherein the liquid composition is acidic.

10. The method according to claim 9, wherein the pH of the liquid composition is 6 or less.

11. The method according to claim 1, further comprising the following step (i-2) between step (i) and step (ii). (i-2) A step of adding an immiscible medium that does not mix with the liquid composition to the liquid composition prepared in step (i).

12. The liquid composition is hydrophobic, and the immiscible medium is hydrophilic, or The method according to claim 11, wherein the liquid composition is hydrophilic and the immiscible medium is hydrophobic.

13. The method according to claim 11, wherein the heating in step (ii) is stirring and heating of the liquid composition.

14. The method according to claim 11, wherein the immiscible medium is a dispersion in which a solid phase containing water-soluble dietary fiber and protein is dispersed in a liquid phase.

15. The method according to claim 14, wherein the heating in step (ii) above includes stirring and heating the liquid composition to gel the liquid composition into a substantially granular form, and forming core-shell-like particles in which the solid phase in the dispersion adheres as a coating layer around the gelled core portion of the liquid composition.

16. A solid composition manufactured by the method described in any one of claims 1 to 15.

17. A granular solid composition, It comprises a granular core containing starch and insoluble dietary fiber, and a gel-like coating layer containing water-soluble dietary fiber and protein that covers the surface of the core. A solid composition in which the core portion is isolated from the outside by the coating layer.

18. The solid composition according to claim 17, wherein the area ratio of void openings to the outer surface of the composition is 10% or more and 30% or less.

19. The solid composition according to claim 18, wherein the hue in the Munsell color system is 0YR to 10YR or 0Y to 5Y.

20. The solid composition according to claim 19, wherein the lightness in the Munsell color system is 9.0 or less.

21. The solid composition according to claim 20, wherein the chroma in the Munsell color system is 4 or higher.

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