JP7575776B2 - Dry food manufacturing method - Google Patents

Description

The present invention relates to a method for producing dried foods, which comprises freeze-drying food materials that contain moisture and have fluidity, thereby producing dried foods that can be eaten without adding water.

For example, the following Patent Document 1 discloses a method for producing freeze-dried fruit. Specifically, in the method disclosed in Patent Document 1, first, the pulp of the fruit is crushed and processed into a paste. At this time, fruit juice, flavorings, acidulants, colorants, gelling agents, sugars, etc. are added as necessary. Next, lipid-containing materials are mixed into the fruit processed into a paste. At this time, if a large amount of lipid-containing materials is mixed, moisture is added to facilitate freezing in a later process. Next, the fruit processed as described above is filled into a container, cooled to -20°C or below and frozen, and then dried by a known freeze-drying process. This completes the dried food.

On the other hand, the following Patent Document 2 discloses a manufacturing method for freeze-drying fruit or vegetable paste or juice to manufacture dried foods. Specifically, in the manufacturing method disclosed in Patent Document 2, first, raw materials such as fruit are processed into a paste, juice, or extract (hereinafter also referred to as a "fluid food material"), and then agar is mixed in. At this time, the fluid food material is heated to fully dissolve the agar, and water is added as necessary to adjust the viscosity to an appropriate level. Next, the fluid food material mixed with agar is filled into a container and cooled. At this time, the fluid food material solidifies into a jelly-like state (hereinafter, the solidified food material is also referred to as a "jelly-like food material"). Next, the jelly-like food material is chopped into arbitrary dimensions. Next, the chopped jelly-like food material is cooled and frozen, and then dried by a known freeze-drying process. This completes the dried food.

JP 2015-208250 A (pages 3-6) JP 2017-012119 A (pages 3-7)

However, the manufacturing methods of Patent Documents 1 and 2 and the dried foods manufactured according to these manufacturing methods have the following problems. Specifically, the manufacturing method disclosed in Patent Document 1 aims to provide "food that does not feel like moisture is being absorbed from the mouth when it is placed in the mouth", and carries out a step of processing the ingredients into a paste-like form and a step of blending a lipid-containing material prior to the freeze-drying process. Meanwhile, the manufacturing method disclosed in Patent Document 2 aims to provide "food that has been processed into granular matter of a size that gives a crisp texture", and carries out a step of blending agar with the ingredients to process them into a jelly-like form and a step of chopping the jelly-like ingredients into any size and shape prior to the freeze-drying process.

In this case, the dried foods produced according to the manufacturing methods disclosed in both Patent Documents 1 and 2 are produced by freeze-drying a single food ingredient in which the raw materials are mixed uniformly (a paste-like fruit mixed with a lipid-containing material in Patent Document 1; a jelly-like food ingredient solidified by mixing agar with a fluid food ingredient in Patent Document 2). As a result, the entire outer surface of the finished food has the same appearance (same color and texture from any angle), and the same texture and taste are perceived no matter where the food is bitten. Therefore, although the dried foods produced according to the manufacturing methods disclosed in both Patent Documents have a different texture from dried foods produced according to conventional manufacturing methods, their appearance and taste are not significantly different from conventional dried foods produced from similar raw materials.

The above-mentioned Patent Document 1 also discloses a manufacturing method for producing coated confectionery by coating a coating material such as chocolate on a dried food produced by freeze-drying. However, even with such a manufacturing method, it is difficult to provide a food that is significantly different in appearance, texture, taste, etc. from existing foods such as baked confectionery coated with chocolate, etc.

On the other hand, the applicant has produced a prototype of a dried food in which two or more types of ingredients differing from each other in color, texture, texture, taste, etc. are arranged in layers and freeze-dried, in order to provide a highly interesting dried food that is significantly different from existing dried foods in terms of appearance, texture, taste, etc. Specifically, as an example, when producing a two-layer dried food using two types of ingredients (hereinafter, these two types of ingredients are also referred to as the "first ingredient" and the "second ingredient"), first, the first ingredient in a paste or liquid form and the second ingredient in a paste or liquid form are each produced (cooked). Next, the first ingredient is placed in a container, and the second ingredient is placed on top of it. Next, both ingredients are freeze-dried in the same manner as in the conventional manufacturing method. This completes the dried food.

However, in the manufacturing process of the dried food prototyped by the applicant, when the second food ingredient is placed in the container, the first food ingredient already placed in the container and the newly placed second food ingredient may mix together in the container. In particular, when one or both of the two food ingredients are liquid (when the ingredients have high fluidity), the degree of mixing of the two food ingredients increases, and in the worst case, they may mix together as if one type of food ingredient was placed in the container. Therefore, even though a two-layer dried food consisting of different ingredients is to be manufactured, a layer of mixed food ingredients in which both ingredients are mixed is formed between the layer of the first food ingredient and the layer of the second food ingredient, or the whole product is formed of mixed food ingredients as in the case of previous dried foods consisting of one type of food ingredient. Therefore, with the above manufacturing method, it is difficult to tell from the appearance that it is a two-layer dried food, and it is difficult to individually perceive the texture and taste of the first food ingredient and the texture and taste of the second food ingredient.

It is possible to reduce the degree of mixing of the two ingredients by gradually adding the second ingredient on top of the first ingredient over time. However, since both ingredients are in a paste or liquid state and contain moisture, the moisture from the first ingredient may penetrate into the layer of the second ingredient or vice versa between the completion of the placement of both ingredients and the start of freeze-drying. Furthermore, the time required to place the second ingredient increases, and this process becomes a bottleneck, reducing the productivity of the dried food and raising the production costs.

The present invention has been made in consideration of such problems, and its main object is to provide a method for producing dried foods that can reliably produce highly interesting dried foods without incurring high production costs.

In order to achieve the above object, the method for producing dried food described in claim 1 is a method for producing dried food that can be eaten without adding water by freeze-drying a food material that contains water and has fluidity, and includes at least a first step of placing a first food material as the food material in a container, a second step of cooling the first food material in the container to reduce the fluidity of the first food material, a third step of placing a second food material as the food material on top of the first food material in the container, and a fourth step of freeze-drying the first food material and the second food material in the container.

The dried food manufacturing method described in claim 2 is the dried food manufacturing method described in claim 1, in which a fifth step of cooling the second food material is carried out prior to the third step.

Furthermore, the dried food manufacturing method described in claim 3 is the dried food manufacturing method described in claim 1 or 2, in which a sixth step of cooking a first raw material to produce the first food ingredient is carried out prior to the first step, and a seventh step of cooking a second raw material to produce the second food ingredient is carried out prior to the third step.

The method for producing dried food according to claim 1 includes at least a first step of storing a first food ingredient in a container, a second step of cooling the first food ingredient in the container to reduce the fluidity of the first food ingredient, a third step of storing a second food ingredient on top of the first food ingredient in the container, and a fourth step of freeze-drying the first food ingredient and the second food ingredient in the container, thereby producing a dried food that can be eaten without adding water.

Therefore, according to the method for producing dried food described in claim 1, by producing a plurality of ingredients layers of the first ingredient layer and the second ingredient layer in an integrated state (laminated state), it is possible to provide a highly interesting dried food with a beautiful appearance and various textures, unlike existing dried foods that have the same overall appearance and have the same texture no matter where they are eaten. In addition, by performing the third step after reducing the fluidity of the first ingredient in the second step, it is possible to reliably and easily prevent the first ingredient previously contained in the container from mixing with the second ingredient to be newly contained in the container. This eliminates the need to slowly add the second ingredient in small amounts, and therefore the production cost of the dried food can be sufficiently reduced. It is also possible to provide a beautiful dried food product in which a first ingredient layer is made up of only the first ingredient, and a second ingredient layer is made up of only the second ingredient, and since there is no mixed ingredient layer in which the first ingredient and the second ingredient are mixed, the texture of the first ingredient layer and/or the texture of the second ingredient layer can be perceived in a favorable manner.

According to the method for producing dried food described in claim 2, by carrying out the fifth step of cooling the second food material prior to the third step, it is possible to effectively avoid a situation in which the temperature of the first food material is raised by the second food material contained in the container body in the third step, thereby reducing the fluidity of the first food material, and therefore it is possible to more effectively prevent the first food material and the second food material from mixing with each other.

According to the method for producing dried food described in claim 3, the sixth step of cooking the first raw material to produce the first food ingredient is carried out prior to the first step, and the seventh step of cooking the second raw material to produce the second food ingredient is carried out prior to the third step. By carrying out all of the processes from the production of the first and second food ingredients (the sixth and seventh steps) to the final fourth step (freeze-drying), the seasoning and cooking method of the first and second food ingredients can be adjusted as desired, taking into consideration the appearance, texture and taste of the first food ingredient layer and the appearance, texture and taste of the second food ingredient layer at the completion of the fourth step, i.e., the state when the fourth step is completed, that is, the state when the first food ingredient is actually edible. Therefore, it is possible to provide a more beautiful and delicious dried food compared to a production method for producing dried food using cooked ingredients (the first and second food ingredients produced by another person) as the first food ingredient used in the first step and the second food ingredient used in the third step.

FIG. 2 is an external perspective view of a two-layer dried food 1. 1 is a perspective view of the appearance of a two-layer dried food 11. FIG. 2 is a flow chart of a two layer dry food manufacturing process 20. FIG. 2 is an explanatory diagram for explaining the texture of the two-layer dried food 1. FIG. 2 is an explanatory diagram for explaining the texture of the two-layer dried food 11.

Hereinafter, an embodiment of a method for producing dried food will be described with reference to the accompanying drawings.

The two-layered dried food 1 shown in FIG. 1 is an "omurice snack (a dried omurice snack)" which is an example of a "dried food that can be eaten without adding water" manufactured according to the "dried food manufacturing method" and is formed in a block shape so that it can be eaten in one bite and chewed in the mouth, or in two or three bites and chewed in the mouth. This two-layered dried food 1 is formed into a two-layer structure in which a first ingredient layer 2 (an example of a "first ingredient layer") corresponding to the "egg layer" in the "omurice" and a second ingredient layer 3 (an example of a "second ingredient layer") corresponding to the "ketchup rice layer" in the "omurice" are laminated together by the two-layered dried food manufacturing process 20 (see FIG. 3) described later.

In this case, the first ingredient layer 2 is formed by freeze-drying a first ingredient 2a (an example of a "first ingredient" as an ingredient that contains moisture and has fluidity) made by cooking ingredients such as eggs, lactose, reduced starch syrup, tapioca starch, coloring agent (β-carotene), salt, and yeast extract (an example of a "first ingredient"). The second ingredient layer 3 is formed by freeze-drying a second ingredient 3a (an example of a "second ingredient" as an ingredient that contains moisture and has fluidity) made by cooking ingredients such as cooked rice, ketchup, butter, reduced starch syrup, tapioca starch, consommé, salt, antioxidants, red koji coloring, citric acid, and yeast extract (an example of a "second ingredient").

The two-layered dried food 11 shown in FIG. 2 is a "curry rice snack (a dried turmeric rice curry snack)" which is another example of a "dried food that can be eaten without adding water" manufactured according to the "dried food manufacturing method", and is formed in a block shape so that it can be eaten in one bite and chewed in the mouth, or in two or three bites and chewed in the mouth. This two-layered dried food 11 is formed into a two-layer structure by the two-layered dried food manufacturing process 20, in which a first ingredient layer 12 (another example of the "first ingredient layer") corresponding to the "curry layer" in "curry rice" and a second ingredient layer 13 (another example of the "second ingredient layer") corresponding to the "rice layer" in "curry rice" are laminated together.

In this case, the first ingredient layer 12 is formed by freeze-drying the first ingredient 12a (another example of the "first ingredient" as an ingredient that contains moisture and has fluidity) made by cooking ingredients such as dried carrots, reduced starch syrup, lactose, curry powder, tapioca starch, cumin powder, consomme, yeast extract, antioxidants, dried parsley, and garam masala powder (another example of the "first ingredient"). The second ingredient layer 13 is formed by freeze-drying the second ingredient 13a (another example of the "second ingredient" as an ingredient that contains moisture and has fluidity) made by cooking ingredients such as cooked rice, reduced starch syrup, tapioca starch, salt, turmeric powder, and antioxidants (another example of the "second ingredient").

Next, the manufacturing method of the two-layer dried food 1 will be explained with reference to the attached drawings.

When producing the two-layered dried food 1, the steps of the two-layered dried food production process 20 shown in Figure 3 are carried out. Note that the weight of each ingredient given as an example in the following explanation is the weight required to produce one piece (one block) of two-layered dried food 1, and in reality, ingredients for multiple pieces (multiple blocks) are cooked at the same time, so ingredients are used in amounts according to the weight ratios given as examples.

First, the first food ingredient 2a is produced (step 21). Specifically, a raw material liquid (hereinafter referred to as "raw material liquid Aa") is produced by mixing whole egg liquid (egg: 1.0 g) and coloring agent (β-carotene: 0.02 g) at room temperature, and a raw material liquid (hereinafter referred to as "raw material liquid Ba") is produced by dissolving reduced starch syrup (0.2 g), salt (0.01 g), lactose (0.5 g), yeast extract (0.01 g) and tapioca starch (0.05 g) in hot water. Next, the raw material liquid Aa is poured into raw material liquid Ba that has been heated to about 90°C to produce so-called "eggs". This produces the first food ingredient 2a (eggs). (An example of the "sixth step of cooking the first raw material to produce the first food ingredient").

Next, the first ingredient 2a thus produced is packed (stored) evenly in a plastic tray (not shown) (an example of a "container") up to about 1/3 of the height of the ingredient storage section (an example of a "first step of storing the first ingredient in a container": step 22). Next, the first ingredient 2a is cooled together with the plastic tray to reduce the fluidity of the first ingredient 2a (an example of a "second step of cooling the first ingredient in the container to reduce the fluidity of the first ingredient": step 23). At this time, the viscosity of the first ingredient 2a is increased to 142 Pa·s or more by cooling it to about 22.5°C.

Next, the second food ingredient 3a is produced (step 24). Specifically, cooked rice (2.0 g), ketchup (0.7 g), consommé (0.05 g), butter (0.2 g), red koji coloring (0.01 g), reduced starch syrup (0.2 g), citric acid (0.01 g), salt (0.02 g), antioxidant (0.02 g), yeast extract (0.01 g) and tapioca starch (0.1 g) are dissolved in hot water and heated at about 80°C for about 3 minutes to produce liquid "ketchup rice". This produces the second food ingredient 3a (ketchup rice liquid) (an example of the "seventh step of cooking second raw materials to produce second food ingredients").

Next, cooling water is added to the second food material 3a thus produced, thereby cooling (reducing the temperature) the second food material 3a to approximately 60°C (step 25, an example of the "fifth step of cooling the second food material"). Note that with regard to the above steps 21 to 23 and steps 24 and 25, steps 21 to 23 may be performed after steps 24 and 25, or steps 21 to 23 may be performed in parallel with steps 24 and 25.

Next, the second food ingredient 3a is evenly packed (stored) on top of the first food ingredient 2a in the plastic tray up to the upper edge of the food ingredient storage section (an example of the "third step of storing the second food ingredient on top of the first food ingredient in the container body": step 26). At this time, in the manufacturing method of this example, since the first food ingredient 2a has been cooled in step 23 and its fluidity has decreased, it is possible to effectively prevent the second food ingredient 3a newly stored in the plastic tray (food ingredient storage section) from mixing with the first food ingredient 2a stored in the plastic tray (food ingredient storage section) before the second food ingredient 3a is stored (a layer of mixed food ingredients of the first food ingredient 2a and the second food ingredient 3a is formed). This forms a layer containing only the first food ingredient 2a and a layer containing only the second food ingredient 3a, respectively.

Also, unlike the manufacturing method of this example, if the second ingredient 3a, which has been heated to a high temperature by the heating in step 24, is placed on top of the first ingredient 2a without performing the above step 25, the high-temperature second ingredient 3a comes into contact with the first ingredient 2a in the plastic tray (ingredient storage section), causing the temperature of the upper part of the first ingredient 2a to rise and become more fluid. Therefore, when manufacturing a "dried food" using an ingredient that requires heating during production (cooking) as the "second ingredient," if the above step 25 is not performed, there is a risk that the "first ingredient" and the "second ingredient" will mix together in the plastic tray (ingredient storage section) (a layer of mixed ingredients of the "first ingredient" and the "second ingredient" will be formed).

In contrast, in the manufacturing method of this example, the second food ingredient 3a is sufficiently cooled in the process of step 25 above, so that when the second food ingredient 3a is placed on top of the first food ingredient 2a in the process of step 26 above, a situation in which the temperature of the first food ingredient 2a in contact with the second food ingredient 3a rises (the fluidity increases) is preferably avoided. As a result, a layer containing only the first food ingredient 2a and a layer containing only the second food ingredient 3a are formed in the plastic tray (food ingredient storage section).

Next, the plastic tray in which the second food ingredient 3a has been contained is cooled to about -25°C and frozen (pre-freezing of food ingredients: step 27). Next, the stack of frozen first and second food ingredients 2a and 3a is contained together with the plastic tray in a vacuum chamber, and the vacuum chamber is evacuated (reduced pressure) (step 28). At this time, the moisture contained in the first and second food ingredients 2a and 3a in the plastic tray (food ingredient container) is sublimated, and the first and second food ingredients 2a and 3a are dried, respectively. This completes the two-layer dried food 1, which is a stack of the first food ingredient layer 2 in which the first food ingredient 2a is dried, and the second food ingredient layer 3 in which the second food ingredient 3a is dried, and the two-layer dried food manufacturing process 20 is completed.

In the manufacturing method of this example, the above steps 27 and 28 correspond to the "fourth step of freeze-drying the first and second ingredients in the container", but depending on the type of "dried food" to be manufactured (the composition of the "first ingredient" and the "second ingredient layer"), the pre-freezing step of step 27 may not be performed and step 28 may be performed as the "fourth step". In this manufacturing method, the "first ingredient" and the "second ingredient" are adiabatically expanded and frozen during the process of reducing the pressure inside the vacuum chamber, and then the moisture contained in the "first ingredient" and the "second ingredient" is sublimated to dry the "first ingredient" and the "second ingredient". This completes the "dried food", which is a laminate of the "first ingredient layer" in which the "first ingredient" is dried and the "second ingredient layer" in which the "second ingredient" is dried.

Next, the manufacturing method of the two-layer dried food 11 will be explained with reference to the attached drawings.

When producing the two-layered dried food 11 described above, the steps of the two-layered dried food production process 20 shown in Figure 3 are carried out. Note that the weight of each ingredient given as an example in the following explanation is the weight required to produce one piece (one block) of two-layered dried food 11, and in reality, ingredients for multiple pieces (multiple blocks) are cooked at the same time, so ingredients are used in amounts according to the weight ratios given as examples.

First, the first food ingredient 12a is produced (step 21). Specifically, curry powder (0.18 g), reduced starch syrup (0.2 g), consommé (0.03 g), lactose (0.2 g), yeast extract (0.01 g), cumin powder (0.06 g), garam masala powder (0.003 g), antioxidant (0.01 g) and tapioca starch (0.18 g) are dissolved in hot water and heated at about 80°C for about 3 minutes, after which dried carrots (0.3 g) and dried parsley (0.01 g) are mixed in. This produces the first food ingredient 12a (curry liquid) (another example of the "sixth step of cooking the first raw materials to produce the first food ingredient").

Next, the first ingredient 12a thus produced is packed (stored) evenly in a plastic tray (not shown) (an example of a "container") up to about half the height of the ingredient storage section (another example of the "first step of storing the first ingredient in a container": step 22). Next, the first ingredient 12a is cooled together with the plastic tray to reduce the fluidity of the first ingredient 12a (another example of the "second step of cooling the first ingredient in the container to reduce the fluidity of the first ingredient": step 23). At this time, the viscosity of the first ingredient 12a is increased to 168 Pa·s or more by cooling it to about 41.7°C.

Next, the second food ingredient 13a is produced (step 24). Specifically, cooked rice (1.5 g), turmeric powder (0.01 g), reduced starch syrup (0.2 g), salt (0.02 g), antioxidant (0.01 g) and tapioca starch (0.18 g) are dissolved in hot water and heated at about 80°C for about 3 minutes to produce liquid "turmeric rice". This produces the second food ingredient 13a (turmeric rice liquid) (another example of the "seventh step of cooking second raw materials to produce second food ingredients").

Next, cooling water is added to the second food material 13a thus produced, thereby cooling (reducing the temperature) the second food material 13a to approximately 60°C (another example of the "fifth step of cooling the second food material": step 25). Note that with regard to the above steps 21 to 23 and steps 24 and 25, steps 21 to 23 can be performed after steps 24 and 25, or steps 21 to 23 can be performed in parallel with steps 24 and 25.

Next, the second food ingredient 13a is evenly packed (stored) on top of the first food ingredient 12a in the plastic tray up to the upper edge of the food ingredient storage section (another example of the "third step of storing the second food ingredient on top of the first food ingredient in the container body": step 26). At this time, in the manufacturing method of this example, since the first food ingredient 12a is cooled in step 23 and its fluidity is reduced, the second food ingredient 13a newly stored in the plastic tray (food ingredient storage section) and the first food ingredient 12a stored in the plastic tray (food ingredient storage section) before the second food ingredient 13a is stored are preferably prevented from mixing (a layer of mixed food ingredients of the first food ingredient 12a and the second food ingredient 13a is formed). As a result, a layer containing only the first food ingredient 12a and a layer containing only the second food ingredient 13a are formed, respectively.

In addition, in the manufacturing method of this example, since the second food ingredient 13a is sufficiently cooled in the process of step 25 above, when the second food ingredient 13a is placed on top of the first food ingredient 12a in the process of step 26 above, a situation in which the temperature of the first food ingredient 12a in contact with the second food ingredient 13a increases (the fluidity increases) is preferably avoided. As a result, a layer containing only the first food ingredient 12a and a layer containing only the second food ingredient 13a are formed in the plastic tray (food ingredient storage section).

Next, the plastic tray in which the second food ingredient 13a has been contained is cooled to about -25°C and frozen (pre-freezing of food ingredients: step 27). Next, the stack of the frozen first food ingredient 12a and second food ingredient 13a is contained in the plastic tray in a vacuum chamber, and the vacuum chamber is evacuated (reduced pressure) (step 28). At this time, the moisture contained in the first food ingredient 12a and second food ingredient 13a in the plastic tray (food ingredient container) is sublimated, and the first food ingredient 12a and second food ingredient 13a are dried, respectively. This completes the two-layer dried food 11, which is a stack of the first food ingredient layer 12 in which the first food ingredient 12a is dried, and the second food ingredient layer 13 in which the second food ingredient 13a is dried, and the two-layer dried food manufacturing process 20 is completed. In the manufacturing method of this example, steps 27 and 28 correspond to the "fourth step of freeze-drying the first and second ingredients in the container."

Next, the differences between the "dried food" manufactured according to the manufacturing methods disclosed in the aforementioned Patent Documents 1 and 2, the "dried food" prototyped by the applicant, and the above-mentioned two-layer dried foods 1 and 11 will be explained with reference to the attached drawings.

The two-layered dried foods 1 and 11 produced according to the above-mentioned manufacturing method have a significantly different appearance from the "dried foods" produced according to the manufacturing method disclosed in the above-mentioned Patent Documents 1 and 2. The two-layered dried foods 1 and 11 also have a different appearance from the "dried foods" prototyped by the applicant. Specifically, as described above, in the manufacturing methods disclosed in both Patent Documents 1 and 2, the ingredients are produced by freeze-drying a single food material in a state in which the raw materials are mixed uniformly. Therefore, the entire outer surface of the finished food has a similar appearance. In addition, in the "dried foods" prototyped by the applicant, depending on the fluidity (viscosity) of the ingredients to be combined and the method of storing them in the container, the ingredients may mix at the boundary between the ingredients to form a layer of mixed ingredients, or in the worst case, the entire food material may be formed of a single food material in which the ingredients are mixed. Therefore, it may be difficult to recognize that they are "multi-layered dried foods".

In contrast, in the two-layered dried foods 1, 11 manufactured according to the manufacturing method of the two-layered dried food manufacturing process 20 described above, during the manufacturing process, after the step of storing the first ingredients 2a, 12a forming the first ingredient layer 2, 12 in a plastic tray (ingredient storage section) (step 22 in the two-layered dried food manufacturing process 20), a step of cooling the first ingredients 2a, 12a in the plastic tray (ingredient storage section) to reduce their fluidity (step 23) is carried out prior to the step of storing the second ingredients 3a, 13a forming the second ingredient layer 3, 13 in the plastic tray (ingredient storage section) (step 26), thereby preventing the first ingredients 2a, 12a and the second ingredients 3a, 13a from mixing in the plastic tray (ingredient storage section).

As a result, as shown in Figs. 1 and 2, in the two-layer dried food 1, 11, the boundary between the first ingredient layer 2, 12 in which the first ingredient 2a, 12a is dried and the second ingredient layer 3, 13 in which the second ingredient 3a, 13a is dried is clear, making it possible to reliably and easily recognize that it is a "two-layer dried food". In this case, in the two-layer dried food 1, 11 of this example in which the color and texture of the first ingredient layer 2, 12 is significantly different from the color and texture of the second ingredient layer 3, 13, it is possible to more reliably and easily recognize that it is a "two-layer dried food". Therefore, by manufacturing according to the above-mentioned "manufacturing method", it is possible to provide a "dried food" with a very unique appearance that cannot be realized with a "dried food" in which the entire outer surface has the same appearance or a "dried food" in which a "mixed ingredient layer" exists between two types of "ingredients layers".

In addition, the two-layered dried foods 1 and 11 have a significantly different taste and texture from the "dried foods" produced according to the manufacturing methods disclosed in the above-mentioned Patent Documents 1 and 2. In addition, the two-layered dried foods 1 and 11 also have a different taste and texture from the "dried foods" prototyped by the applicant. Specifically, the manufacturing methods disclosed in both Patent Documents 1 and 2, as described above, are produced from a single food material in which the raw materials are mixed uniformly, so that the same texture and taste are perceived no matter where the food is nibbled. In addition, in the "dried foods" prototyped by the applicant, when a layer of mixed food material is formed at the boundary between the food materials, there is a portion where the texture and taste of the mixed food material is perceived as different from the texture and taste of one of the two food materials and the texture and taste of the other of the two food materials, and when the degree of mixing of the two food materials is high, only the texture and taste of the mixed food material, which is different from the texture and taste of the two food materials, is perceived.

In contrast, in the two-layered dried foods 1, 11 produced according to the above-mentioned two-layered dried food production process 20, as described above, the boundary between the first ingredient layer 2, 12 in which the first ingredient 2a, 12a is dried and the second ingredient layer 3, 13 in which the second ingredient 3a, 13a is dried is clear. As a result, the two-layered dried foods 1, 11 of this example are produced so that different tastes and textures are perceived when only the first ingredient layer 2, 12 is eaten (bitten), when only the second ingredient layer 3, 13 is eaten (bitten), and when the first ingredient layer 2, 12 and the second ingredient layer 3, 13 are eaten (bitten) together. Therefore, by producing according to the above-mentioned "production method", it is possible to provide a highly original "dried food" that cannot be realized with a "dried food" produced from a single ingredient in which the raw materials are mixed uniformly, or a "dried food" in which a layer of mixed ingredients is unintentionally mixed.

Specifically, in the two-layered dried food 1, which is an "omurice snack," when only the first ingredient layer 2 is eaten, the taste of "cooked egg" is perceived, when only the second ingredient layer 3 is eaten, the taste of "ketchup rice" is perceived, and when the first ingredient layer 2 and the second ingredient layer 3 are eaten together, the taste of "omurice (cooked egg and ketchup rice)" is perceived. In addition, in the two-layered dried food 11, which is a "curry rice snack," when only the first ingredient layer 12 is eaten, the taste of "curry" is perceived, when only the second ingredient layer 13 is eaten, the taste of "turmeric rice" is perceived, and when the first ingredient layer 12 and the second ingredient layer 13 are eaten together, the taste of "curry rice (curry and turmeric rice)" is perceived.

Furthermore, in the two-layered dried foods 1 and 11, the texture of the first ingredient layer 2, 12 alone is different from the texture of the second ingredient layer 3, 13 alone. Specifically, a texture tester "TEX-100N" manufactured by Japan Measurement Systems Co., Ltd. was used to measure the force required to pierce the first ingredient layer 2 and second ingredient layer 3 in the two-layered dried food 1 and the first ingredient layer 12 and second ingredient layer 13 in the two-layered dried food 11 (the maximum load measured when the plunger pierces the ingredient layers 12, 13: an example of a parameter that influences the "texture perceived when biting into the food").

Specifically, three samples were prepared in which the first ingredient layer 2, 12 in the two-layered dried food 1, 11 was produced by itself in the same procedure as each step except for steps 24-26 in the two-layered dried food production process 20, and three samples were prepared in which the second ingredient layer 3, 13 in the two-layered dried food 1, 11 was produced by itself in the same procedure as each step except for steps 21-23 in the two-layered dried food production process 20, and measurements were performed on each sample. In the measurement, as an example, a plunger with a conical tip and a diameter of 20 mm was lowered toward the first ingredient layer 2 or the second ingredient layer 3 at a speed of 100 mm/min, and the maximum load applied to the plunger from when the tip of the plunger contacted the first ingredient layer 2 or the second ingredient layer 3 until it was lowered 20 mm (until the tip reached a depth of 20 mm) was measured as the "force required to pierce to a predetermined depth at a predetermined speed."

As a result of this measurement process, as shown in FIG. 4, in the two-layer dried food 1, the average maximum load (N) obtained for each sample of the first food layer 2 was 76.21 N, while the average maximum load (N) obtained for each sample of the second food layer 3 was 29.54 N. In other words, it can be seen that in the two-layer dried food 1, the second food layer 3 has a softer texture than the first food layer 2.

In the two-layer dried food 1, the maximum load obtained for the sample of the first ingredient layer 2 is more than twice the maximum load obtained for the sample of the second ingredient layer 3. In this case, as shown in FIG. 1, in the two-layer dried food 1, the first ingredient layer 2, which has a harder texture than the second ingredient layer 3, is formed thinner than the second ingredient layer 3. Therefore, when the first ingredient layer 2 and the second ingredient layer 3 are eaten together, the second ingredient layer 3 can be easily chewed due to its own softness, and the first ingredient layer 2 can be chewed relatively easily after some resistance is felt due to its own hardness.

This texture is similar to the sensation felt when eating a normal omelet rice, which is not a "dried food," with the utensil (spoon, etc.) or teeth breaking through the thin layer of egg to reach the ketchup rice, resulting in a highly interesting texture that is difficult to achieve with conventional "dried foods" made from a single ingredient. When the first ingredient layer 2 in the two-layer dried food 1 is made thinner than the second ingredient layer 3, in addition to the improvement in texture as described above, there is also the advantage that when the two-layer dried food 1 is visually inspected, the first ingredient layer 2 is intuitively recognized as the part that corresponds to the "cooked egg layer" in the "omelet rice."

On the other hand, as shown in FIG. 5, in the two-layer dried food 11, the average maximum load (N) obtained for each sample of the first food layer 12 was 59.90 N, while the average maximum load (N) obtained for each sample of the second food layer 13 was 14.31 N. In other words, it can be seen that in the two-layer dried food 11, the second food layer 13 has a softer texture than the first food layer 12.

In addition, in the two-layer dried food 11, the maximum load obtained for the sample of the first ingredient layer 12 is more than twice the maximum load obtained for the sample of the second ingredient layer 13. In this case, as shown in FIG. 2, in this two-layer dried food 11, unlike the two-layer dried food 1 described above, the first ingredient layer 12 and the second ingredient layer 13 are formed to approximately the same thickness. Therefore, when the first ingredient layer 12 and the second ingredient layer 13 are eaten together, the soft second ingredient layer 13 is chewed first, and then the first ingredient layer 12, which has a certain degree of hardness, is chewed.

At this time, the first ingredient 12a constituting the first ingredient layer 12 contains spice ingredients such as curry powder and garam masala powder, as described above. Therefore, when the two-layer dried food 11 is eaten, the second ingredient layer 13 is chewed before the first ingredient layer 12, so that the taste of the turmeric rice is perceived, and then the first ingredient layer 12 is chewed and the spiciness of the spices in the curry is perceived, resulting in a highly unique texture that is difficult to achieve with conventional "dried foods" made of a single ingredient.

In this way, by optimizing the "force (i.e., hardness) required to penetrate the conical tip measuring probe to a predetermined depth at a predetermined speed" in the "first ingredient layer" and the "second ingredient layer" and the ratio of the thicknesses of the "first ingredient layer" and the "second ingredient layer" according to the texture to be achieved in the "dried food" to be manufactured, it is possible to perceive a variety of textures that are difficult to perceive in a "dried food" made entirely from a single ingredient.

In this case, the applicant produced a "two-layered dried food" (not shown) consisting of a first food layer 2 and a second food layer 3 similar to the two-layered dried food 1 described above, using a manufacturing method different from the manufacturing method described above. Specifically, as an example, a sample of the first food layer 2 and a sample of the second food layer 3 (hereinafter simply referred to as the "first food layer 2" and the "second food layer 3") generated during the above measurement process were bonded together with starch syrup or the like (a food that can bond foods together: hereinafter also referred to as an "edible adhesive") to produce a "two-layered dried food".

In this case, if a sufficient amount of edible adhesive is used to bond the first and second ingredient layers 2 and 3 together, the first and second ingredient layers 2 and 3 can be maintained in an integrated state from completion to eating (biting). However, if a small amount of edible adhesive is used, the adhesive strength of the first and second ingredient layers 2 and 3 may be insufficient, causing them to separate before eating or the moment you start to bite into them.

Although the first and second food layer 2 and 3 can be integrated with sufficient adhesive strength by using a sufficient amount of edible adhesive, when the edible adhesive is applied to the first and/or second food layer 2 and 3 during the manufacturing stage, the moisture in the edible adhesive penetrates into the applied object (the first and/or second food layer 2 and 3), deteriorating the texture and appearance of the permeated area. Furthermore, a thin layer of edible adhesive different from the first and second food layer 2 and 3 may be present, which may give an unpleasant feeling different from the texture of the first and second food layer 2 and 3 (deteriorating the texture of the two-layer dried food).

When the first and second food layers 2 and 3 are integrated using an edible adhesive such as starch syrup, in addition to the process of applying the edible adhesive to either or both of the first and second food layers 2 and 3, a process of drying the applied edible adhesive is required. This increases the time required to manufacture the two-layered dried food, and the manufacturing process of the two-layered dried food is increased by the amount of the drying process of the edible adhesive, making it difficult to reduce the manufacturing cost. Furthermore, in a "two-layered dried food" having a thin "food layer" such as the first food layer 2 in the two-layered dried food 1 of this example, there is a risk that the thin "food layer" will be damaged prior to adhesion. For this reason, in a manufacturing method in which separately generated "food layers" are bonded and integrated with an edible adhesive to manufacture a "two-layered dried food," it is difficult to inexpensively manufacture a "two-layered dried food" with good appearance and texture, and there is also a problem that the yield rate decreases due to damage to the "food layer."

In contrast, in the two-layer dried food 1 produced according to the above-mentioned "production method," the first ingredient layer 2a and the second ingredient layer 3a are freeze-dried in contact with each other. Therefore, the first ingredient layer 2 and the second ingredient layer 3 are produced in a state where they are integrated with sufficient strength without using an edible adhesive or the like, and since the thin first ingredient layer 2 does not exist alone, it is possible to preferably avoid its breakage. In addition, since no edible adhesive or the like is applied, the appearance and texture of the first ingredient layer 2 and the second ingredient layer 3 are not deteriorated, and since there is no edible adhesive layer, the two-layer dried food 1 is produced in a state where there are no parts with a texture different from that of the first ingredient layer 2 and the second ingredient layer 3.

In this way, the method for producing the two-layered dried food 1, 11 includes at least the "first step" of storing the first food ingredient 2a, 12a in the container, the "second step" of cooling the first food ingredient 2a, 12a in the container to reduce the fluidity of the first food ingredient 2a, 12a, the "third step" of storing the second food ingredient 3a, 13a on top of the first food ingredient 2a, 12a in the container, and the "fourth step" of freeze-drying the first food ingredient 2a, 12a and the second food ingredient 3a, 13a in the container, to produce the two-layered dried food 1, 11 that can be eaten without adding water.

Therefore, according to the manufacturing method of the two-layered dried food 1, 11 and the two-layered dried food 1, 11 manufactured according to such a manufacturing method, the first food layer 2, 12 and the second food layer 3, 13 are manufactured in an integrated (laminated) state, and unlike existing "dried foods" that have the same overall appearance and the same texture no matter where they are eaten, the two-layered dried food 1, 11 can be provided that has a beautiful appearance and allows various textures to be perceived, which is highly appealing. In addition, by performing the "third step (step 26)" after reducing the fluidity of the first food 2a, 12a by the "second step (step 23 in the two-layered dried food manufacturing process 20)," it is possible to reliably and easily prevent the first food 2a, 12a previously contained in the container from being mixed with the second food 3a, 13a to be newly contained in the container. This eliminates the need to slowly add the second food ingredient 3a, 13a in small amounts, and therefore allows a substantial reduction in the manufacturing cost of the two-layered dried food 1, 11. It also allows the provision of a beautiful two-layered dried food 1, 11 in which the first food ingredient layer 2, 12 is made up of only the first food ingredient 2a, 12a, and the second food ingredient layer 3, 13 is made up of only the second food ingredient 3a, 13a, and the absence of a mixed food ingredient layer in which the first food ingredient 2a, 12a and the second food ingredient 3a, 13a are mixed allows the texture of the first food ingredient layer 2, 12 and/or the texture of the second food ingredient layer 3, 13 to be perceived in a favorable manner.

In addition, according to the method for producing the two-layered dried food 1, 11 and the two-layered dried food 1, 11 produced according to such a method, by carrying out the "fifth step" of cooling the second food ingredient 3a, 13a prior to the "third step", it is possible to preferably avoid a situation in which the temperature of the first food ingredient 2a, 12a is raised by the second food ingredient 3a, 13a contained in the container body in the "third step", thereby reducing the fluidity of the first food ingredient 2a, 12a, and therefore it is possible to more preferably prevent the first food ingredient 2a, 12a and the second food ingredient 3a, 13a from mixing with each other.

Furthermore, according to the method for producing the two-layered dried food 1, 11 and the two-layered dried food 1, 11 produced according to such a production method, a "sixth step" is carried out prior to the "first step" to cook the "first raw material" to produce the first food ingredient 2a, 12a, and a "seventh step" is carried out prior to the "third step" to cook the "second raw material" to produce the second food ingredient 3a, 13a. By carrying out all of the processes from the production of the first food ingredient 2a, 12a and the second food ingredient 3a, 13a (the sixth step and the seventh step) to the final step of the "fourth step (freeze-drying)", the completion of the "fourth step" is possible. Since the seasoning and cooking method of the first food ingredient 2a, 12a and the second food ingredient 3a, 13a can be adjusted as desired, taking into consideration the appearance, texture, and taste of the first food ingredient layer 2, 12 at the time of preparation, i.e., the state in which it is actually possible to eat, and the appearance, texture, and taste of the second food ingredient layer 3, 13, it is possible to provide a two-layer dried food 1, 11 that is more beautiful and more delicious than a manufacturing method that produces a "dried food" using "cooked food ingredients ("first food ingredient" and "second food ingredient" produced by another person)" as the "first food ingredient" used in the "first step" and the "second food ingredient" used in the "third step", respectively.

The two-layer dried food 1, 11 also comprises at least a first ingredient layer 2, 12 made up of a first ingredient 2a, 12a in a dried state and a second ingredient layer 3, 13 made up of a second ingredient 3a, 13a in a dried state, and the force required to pierce a plunger with a conical tip to a predetermined depth (20 mm in this example) at a predetermined speed (100 mm/min in this example) differs between the first ingredient layer 2, 12 and the second ingredient layer 3, 13.

Therefore, according to this two-layered dried food 1, 11, by having the first ingredient layer 2, 12 and the second ingredient layer 3, 13 that differ from each other not only in appearance (color and material) of each ingredient layer 2, 3, 12, 13, but also in texture, the two-layered dried food 1, 11 can be eaten in three different ways: the texture perceived when eating only the first ingredient layer 2, 12, the texture perceived when eating only the second ingredient layer 3, 13, and the texture perceived when eating the first ingredient layer 2, 12 and the second ingredient layer 3, 13 together. This makes it possible to provide a highly unique two-layered dried food 1, 11 that is completely different from existing "dried foods" made of a single type of ingredient.

The specific content of the "dried food manufacturing method" is not limited to the example of the procedure of the two-layer dried food manufacturing process 20 described above.

For example, the configurations and manufacturing methods of the two-layered dried food 1 consisting of a first ingredient layer 2 and a second ingredient layer 3, and the two-layered dried food 11 consisting of a first ingredient layer 12 and a second ingredient layer 13 have been described as examples, but it is also possible to have a configuration having three or more "ingredient layers" and to use a manufacturing method similar to that of the two-layered dried foods 1 and 11 during their manufacture.

Specifically, as an example, when manufacturing a "three-layer dried food" having three "food layers" of layers A, B, and C, the steps are: generating food A constituting layer A (sixth step), placing food A in the container (first step), cooling food A (second step), generating food B constituting layer B (sixth step), placing food B in the container (first step), cooling food B (second step), generating food C constituting layer C (seventh step), placing food C in the container (third step), and freeze-drying food A to C (fourth step). In addition, if necessary, food B can be cooled (fifth step) before placing food B in the container, or food C can be cooled (fifth step) before placing food C in the container. By the above manufacturing method, a three-layer "dried food" with high ingenuity like the two-layer dried foods 1 and 11 described above can be manufactured at low cost.

Also, an example of a manufacturing method has been described in which the "fifth step (step 25)" of cooling the second food ingredient 3a, 13a is carried out prior to the "third step (step 26 in the two-layer dried food manufacturing process 20)". However, when the temperature of the "second food ingredient" is sufficiently low (when the temperature of the "second food ingredient" is not so high that it would cause the "first food ingredient" to become significantly more fluid when placed on top of the "first food ingredient"), the "fifth step" may be unnecessary.

Also, an example of a manufacturing method has been described in which a "sixth step (step 21)" is carried out prior to the "first step (step 22 in the two-layer dried food manufacturing process 20)" in which a "first raw material" is cooked to produce a first food ingredient 2a, and a "seventh step (step 24)" is carried out prior to the "third step (step 26)" in which a "second raw material" is cooked to produce a second food ingredient 3a. However, it is also possible to manufacture a "dried food" by using "water-containing, fluid food ingredients" manufactured by another person for either or both of the "first food ingredient" and the "second food ingredient."

In addition, the configuration of the two-layer dried foods 1, 11 having a first food layer 2, 12 and a second food layer 3, 13 that are different from each other in the "force required to pierce a conical-tip measuring probe to a predetermined depth at a predetermined speed" (have different textures) has been described above, but the "dried food" can also be configured to have a "first food layer" and a "second food layer" that are similar in "force" (have similar textures) as described above.

Also, the above description has been given of a "dried food manufacturing method" in which a "second step of cooling the first food ingredient in the container to reduce the fluidity of the first food ingredient" is carried out prior to a "third step of placing the second food ingredient on top of the first food ingredient in the container". However, instead of this "second step", a "step of reducing the fluidity of the first food ingredient by adding a fluidity-reducing ingredient to the first food ingredient" is carried out prior to the "first step of placing the first food ingredient in the container", thereby making it possible to avoid the "first food ingredient" and the "second food ingredient" from mixing together in the "third step". In this case, the above-mentioned "fluidity-reducing ingredient" can be, for example, "edible starch".

In addition, the manufacturing methods for the two-layer dried food 1 of "Omelette Rice Snack" and the two-layer dried food 11 of "Curry Rice Snack" have been explained as examples, but various other foods such as "Hayashi Rice Snack (a dried food similar to dried Hayashi rice)" and "Tenshinhan Snack (a dried food similar to dried Tenshinhan)" can also be manufactured using manufacturing methods similar to those for the two-layer dried foods 1 and 11 described above.

1, 11 Two-layer dried food 2, 12 First food layer 2a, 12a First food 3, 13 Second food layer 3a, 13a Second food 20 Two-layer dried food manufacturing process

Claims (3)

A method for producing a dried food product that can be eaten without adding water by freeze-drying a food material that contains water and has fluidity, comprising the steps of:
A first step of housing a first food material as the food material in a container body;
a second step of cooling the first food material in the container to reduce the fluidity of the first food material;
A third step of accommodating a second food ingredient as the food ingredient on top of the first food ingredient in the container body;
and a fourth step of freeze-drying the first food material and the second food material within the container. The method for producing dried food according to claim 1, further comprising carrying out a fifth step of cooling the second food material prior to the third step. Prior to the first step, a sixth step is carried out in which a first raw material is cooked to produce the first food ingredient;
3. The method for producing a dried food according to claim 1 or 2, further comprising the step of: prior to the third step, carrying out a seventh step of cooking a second raw material to produce the second food ingredient .

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