WO2024204757A1 - Method for producing solid food, solid food, and method for improving solubility of solid food - Google Patents

Abstract

The present invention addresses the problem of providing a novel method for producing a solid food. The solution to the problem is a method for producing a solid food, the method comprising: a filling step in which a container is filled with a powder including lipid and sugar; and a moist-heat treatment step in which, after the filling step, the powder is subjected to a moist-heat treatment under conditions of a relative humidity of 10% or more and a temperature of 80°C or more.

Description

Method for producing solid food, solid food, and method for improving solubility of solid food

The present invention relates to a method for producing a solid food, a solid food, and a method for improving the solubility of a solid food.

Solid foods such as solid milk made by compressing and molding milk powder have been attracting attention in recent years (see Patent Document 1 and Patent Document 2).

Conventionally, a known technique for forming solid foods is to compress and mold powder using a compression molding machine, and then create recesses in specified positions, as described in Patent Document 1.

Furthermore, regarding the molding of solid foods, Patent Document 2 describes a technology for compressing and molding powder, and hardening the solid foods to a hardness of 20 N or more.

Patent No. 5744963 Patent No. 6972446

In view of the above-mentioned prior art, an object of the present invention is to provide a novel technique for producing solid foods.
In a preferred embodiment of the present invention, an object of the present invention is to provide a technique for producing a solid food having excellent solubility.
In a further preferred embodiment of the present invention, an object is to provide a solid food that has both high solubility and strength.
In addition, in a further preferred embodiment of the present invention, an object is to provide a technology for producing a more soluble solid food by increasing the lipid and protein content in the solid content of the powder.

That is, the present invention which solves the above problems is:
A filling step of filling a container with a powder containing lipids and carbohydrates;
a moist heat treatment step of subjecting the powder after the filling step to moist heat treatment under conditions of a relative humidity of 10% or more and a temperature of 80° C. or more;
A method for producing a solid food product comprising the steps of:

In a preferred embodiment of the present invention, the filling step is a step of filling the container with the powder so as not to compress the powder,
The step of compressing the powder is not included between the filling step and the moist heat treatment step.
By using the above-mentioned form, a solid food with excellent solubility can be produced.

In a preferred embodiment of the present invention, the moist heat treatment step is a step of moist heat treating the powder using a steam oven.

In a preferred embodiment of the present invention, the moist heat treatment step comprises:
A bonding process for bonding powder particles on the outer surface of the powder to each other;
a solidification process in which the bound powder particles are dried to solidify the powder particles;
This process combines the above.
By using the above-mentioned form, solid food can be produced efficiently.

In a preferred embodiment of the present invention, the moist heat treatment step is a step of moist heat treating the powder after the filling step under conditions of a relative humidity of 10% to 100% and a temperature of 120° C. or higher.
In a preferred embodiment of the present invention, the powder has a loose bulk density of 0.6 g/ ^cm3 or less before the moist heat treatment step.
By using the above-mentioned form, a solid food with excellent solubility can be produced.

In a preferred embodiment of the present invention, the particle size distribution of the powder satisfies at least one of the following conditions (A) to (D):
(A) particles having a particle diameter of 125 μm or more account for 50% by mass or more and 90% by mass or less;
(B) particles having a particle size of 125 μm or more and less than 250 μm account for 25% by mass or more and 60% by mass or less;
(C) 90% by mass or more of particles having a particle diameter of 75 μm or more;
(D) Particles having a particle diameter of less than 425 μm are preferably 98% by mass or less

In a preferred embodiment of the present invention, the degree of change in density from the powder before the moist heat treatment step to the solid food after the moist heat treatment step, represented by the following formula (1), is 0.8 or more and 1.2 or less.
Density change rate = (density of solid food) / (loose bulk density of powder before moist heat treatment process) ... (1)

The present invention also includes a powder comprising lipids and carbohydrates,
a solid food product having a graspable outer surface,
The solid food has a density of 0.6 g/cm3 or less.
The solid food in the above form has excellent solubility.

In a preferred embodiment of the present invention, the solid food dissolves in hot water at 60°C to 70°C when the solid food is dropped into the hot water so that the solute concentration is 3% to 15% by mass.

In a preferred embodiment of the present invention, the solid food has a hardness of 1 kgf or more and 5 kgf or less under the following hardness measurement conditions.
[Hardness Measurement]
The device used was a texture analyzer "TA.XT.plus" manufactured by Eiko Seiki Co., Ltd., and a spherical plunger with a diameter of 10 mm was inserted 5 mm into a sample measuring 1.9 cm x 1.9 cm x 2.0 cm in height at room temperature at 1.0 mm/s, and the measured breaking strength was taken as the hardness. In the present invention, "room temperature" refers to a temperature in an environment of 15 to 30°C.

Further, the present invention to solve the above-mentioned problems provides a method for improving the solubility of a solid food, comprising the steps of:
A filling step of filling a container with a powder containing lipids and carbohydrates;
The method for improving the solubility of a solid food also includes a moist heat treatment step of subjecting the powder after the filling step to moist heat treatment under conditions of a relative humidity of 10% or more and a temperature of 80°C or more.
By using the above-mentioned form, a solid food with excellent solubility can be produced.

In a preferred embodiment of the solubility improving method of the present invention, the filling step is a step of filling the powder into a container so as not to compress the powder,
The step of compressing the powder is not included between the filling step and the moist heat treatment step.

The present invention provides a novel method for producing solid foods.

FIG. 2 is a diagram showing the particle size distribution of powder A. FIG. 1 is a diagram showing the results of Test Example 1. FIG. 13 is a diagram showing the results of Test Example 3. FIG. 13 is a diagram showing the results of Test Example 3. FIG. 13 is a diagram showing the results of the solubility test of Test Example 5, test system for solid food C (comparative example).

The following describes the embodiments of the present invention to aid in understanding the present invention. However, the present invention is not limited to the preferred embodiments below, and can be freely modified within the scope of the present invention. In this specification, percentages are expressed by mass unless otherwise specified.

<Method of manufacturing solid food>
The method for producing a solid food product of the present invention includes filling a powder into a container and subjecting the powder to a moist heat treatment under specific conditions.

As used herein, "powder" refers to a raw material before being subjected to the method for producing a solid food of the present invention.
In addition, in this specification, the term "solid food" refers to food that has been subjected to the filling process and the moist heat treatment process and is in a state ready for consumption by consumers.

Below, we will explain in detail the implementation of each step in the method for producing solid foods of the present invention.

[Filling process]
The filling step is a step of filling the powder into the container. Here, the container in the present invention is not particularly limited as long as it can be filled with the powder, but it is preferably a heat-resistant container that does not deform even when subjected to the moist heat treatment described below, and is preferably made of metal such as stainless steel, heat-resistant plastic, or silicon. Specifically, a mold for confectionery (frame) or a mold formed into a desired shape can be used as the container of the present invention.

First, we will show the preferred form of the raw material (powder) before it is subjected to the filling process.

In a preferred embodiment of the present invention, the powder contains lipids.

The lipid content in the powder is preferably 10% by mass or more, more preferably 15% by mass or more, more preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 26.5% by mass or more, of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

In addition, the lipid content in the powder is preferably 50% by mass or less, more preferably 45% by mass or less, more preferably 40% by mass or less, more preferably 35% by mass or less, and more preferably 30% by mass or less, of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

Here, in the present invention, a form containing fat other than milk fat (hereinafter referred to as regulated fat) may also be used.
When a modified fat is contained as the lipid, the content of the modified fat in the powder is preferably 10% by mass or more, more preferably 15% by mass or more, more preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 26% by mass or more of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

Furthermore, when adjusted fat is contained as the lipid, the content of adjusted fat in the powder is preferably 50% by mass or less, more preferably 45% by mass or less, more preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

Here, when milk fat is contained as the lipid, the content of milk fat in the powder is preferably 1 mass% or more, more preferably 3 mass% or more, more preferably 5 mass% or more, more preferably 10 mass% or more, more preferably 15 mass% or more, more preferably 25 mass% or more, and even more preferably 26 mass% or more of the total powder.
By using the powder in the above form, a solid food with high solubility can be produced.

Furthermore, when milk fat is contained as the lipid, the milk fat content in the powder is preferably 50% by mass or less, more preferably 45% by mass or less, more preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

In a preferred embodiment of the present invention, the powder also contains carbohydrates.

The carbohydrate content in the powder is preferably 30% by mass or more, more preferably 35% by mass or more, more preferably 40% by mass or more, more preferably 45% by mass or more, and more preferably 50% by mass or more of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

In addition, the carbohydrate content in the powder is preferably 80% by mass or less, more preferably 75% by mass or less, more preferably 70% by mass or less, more preferably 65% by mass or less, and even more preferably 60% by mass or less, of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

Here, when lactose is contained as a carbohydrate, the lactose content in the powder is preferably 30% by mass or more, more preferably 35% by mass or more, more preferably 40% by mass or more, more preferably 45% by mass or more, and more preferably 50% by mass or more of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

Furthermore, when lactose is contained as a carbohydrate, the lactose content in the powder is preferably 80% by mass or less, more preferably 75% by mass or less, more preferably 70% by mass or less, more preferably 65% by mass or less, more preferably 60% by mass or less, and even more preferably 55% by mass or less of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

When sugars other than lactose are contained as carbohydrates, the content of sugars other than lactose in the powder is preferably 1% by mass or more, more preferably 2% by mass or more, more preferably 3% by mass or more, and more preferably 4% by mass or more of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

Furthermore, when sugars other than lactose are contained as carbohydrates, the content of sugars other than lactose in the powder is preferably 10% by mass or less, more preferably 7% by mass or less, and more preferably 5% by mass or less of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

In a preferred embodiment of the present invention, the powder also contains protein.

The protein content in the powder is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more, of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

The protein content in the powder is preferably 25% by mass or less, more preferably 20% by mass or less, and more preferably 15% by mass or less, of the entire powder.
By using the powder in the above form, a solid food with high solubility can be produced.

Proteins used in the present invention include animal proteins such as milk protein, egg protein, and collagen, and vegetable proteins such as soy protein, rice protein, and wheat protein.

In the present invention, milk proteins can be particularly preferably used. Examples of milk protein sources that can be used include casein, casein hydrolysates, caseinates such as sodium caseinate and calcium caseinate, skim milk powder, concentrated skim milk, milk protein concentrate (MPC), whey powder, whey protein concentrate (WPC), and whey protein hydrolysates.
There are no particular limitations on the type of protein, so long as it is one that can be used in foods.

Here, it is preferable that the total mass of lipids and carbohydrates in the powder accounts for the largest proportion of the total mass of the powder.
By increasing the lipid and carbohydrate content in the powder, a more soluble solid food can be produced.

The lipid and carbohydrate content in the entire powder is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 75% by mass or more, more preferably 80% by mass or more, and even more preferably 83% by mass or more.
By increasing the lipid and carbohydrate content in the powder, a more soluble solid food can be produced.

The lipid and protein content in the entire powder is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more.
By increasing the lipid and protein content in the solid content of the powder, a more soluble solid food can be produced.

The mass ratio of lipid to carbohydrate content in the solid food is preferably within the range of 1:0.5 to 1:4.0, more preferably 1:0.5 to 1:3.7, and more preferably 1:0.5 to 1:3.5.
By setting the lipid and carbohydrate content ratio in the powder within the above range, a solid food with higher solubility can be produced.

In addition, it is preferable that the particle size distribution of the powder satisfies at least one of the following conditions (A) to (D).

(A) Particles having a particle size of 125 μm or more account for preferably 50 mass % or more, further preferably 60 mass % or more, further preferably 70 mass % or more, and particularly preferably 75 mass % or more.
(A') Particles having a particle size of 125 μm or more account for preferably 90% by mass or less, more preferably 80% by mass or less.

(B) Particles having a particle size in the range of 125 μm or more and less than 250 μm preferably account for 25 mass % or more, further preferably 30 mass % or more, and further preferably 40 mass % or more.
(B') Particles having a particle size in the range of 125 μm or more and less than 250 μm account for preferably 60 mass % or less, more preferably 55 mass % or less, and even more preferably 50 mass % or less.

(C) Particles with a particle size of 75 μm or more preferably account for 90% or more by mass, more preferably 89% or more by mass, and particularly preferably 88% or more by mass.

(D) The percentage of particles with a particle size of less than 425 μm is preferably 98% by mass or less, and more preferably 97% by mass or less.

Here, it is preferable that the form satisfies two or more of the above conditions related to the particle size distribution of the powder, more preferably three or more, more preferably four or more, more preferably five or more, and even more preferably all of the conditions.

By keeping the particle size distribution of the powder within the above range, it is possible to produce a solid food with higher solubility.

To measure the median diameter, a laser diffraction particle size distribution measuring device can be used, for example, the Mastersizer 3000 manufactured by Malvern Panalytical.

The powder can be prepared by pulverizing the raw material liquid by spray drying, freeze drying, vacuum drying, etc. Also, it may be a mixture of powders obtained in this way. Alternatively, commercially available creaming powder or infant formula may be used. Mixing can be performed using a V-type, W-type, drum-type, or other mixer used in the industrial production of medicines and foods.

Next, we will explain in detail the filling method used in the filling process.

In a preferred embodiment of the present invention, the filling step is a step of filling the container with the powder without compressing it.

Here, in this specification, "without compressing the powder" does not include an operation of applying pressure to the entire powder using a machine such as a compressor.
Specifically, for example, in this embodiment, the powder is poured into a mold (corresponding to a container in the present invention) prepared in advance, and then the mold (corresponding to a container in the present invention) is gently vibrated to level the powder. Thereafter, the powder protruding from the upper end of the mold (corresponding to a container in the present invention) is leveled by scraping.
By filling the container with the powder without compressing it as described above, a solid food with higher solubility can be produced.

The loose bulk density of the powder filled in the container is preferably 0.3 g/cm ³ or more, more preferably 0.35 g/cm ³ or more, and even more preferably 0.4 g/cm ³ or more.
By filling a container with powder so that the loose bulk density is within the above range, a solid food with higher solubility can be produced.

The loose bulk density of the powder filled in the container is preferably 0.6 g/cm ³ or less, more preferably 0.55 g/cm ³ or less, and even more preferably 0.5 g/cm ³ or less.
By filling a container with powder so that the loose bulk density is within the above range, a solid food with higher solubility can be produced.

Furthermore, the volume of the container is preferably 3 ^cm3 or more, more preferably 5 ^cm3 or more, more preferably 7 ^cm3 or more, more preferably 10 ^cm3 or more, and even more preferably 14 ^cm3 or more.
The volume of the container is preferably 30 ^cm3 or less, more preferably 25 ^cm3 or less, more preferably 20 ^cm3 or less, and more preferably 15 ^cm3 or less.
By filling the container with powder, a more soluble solid food can be produced.

Here, the volume of the container can be a value measured using a VOLSCAN (laser).
The loose bulk density of the powder filled in the container can be calculated based on the volume of the container measured with a VOLSCAN VSP600 (Eiko Seiki) and the weight of the powder filled.

The thickness of the container is preferably 0.3 cm or more, more preferably 0.4 cm or more, and further preferably 0.5 cm or more.
The thickness of the container is preferably 5 cm or less, more preferably 3 cm or less, more preferably 1.5 cm or less, and even more preferably 1.1 cm or less.
By filling the container with powder, a more soluble solid food can be produced.
Furthermore, by setting the thickness of the container to be equal to or less than the upper limit, the electric heat efficiency of the container itself is improved, and solid food can be produced more efficiently.

In this embodiment, the container is formed into a rectangular or elliptical shape when viewed from above.
However, there are no particular restrictions on the three-dimensional shape of the container, and it may be any of a roughly rectangular parallelepiped, roughly spherical, or a shape that imitates a specific design of an animal (dog, cat, etc.), building (Arc de Triomphe, Tokyo Dome), vehicle (motorcycle, ship, etc.), or everyday item (cup, tableware, etc.).

The container may be any container that can be filled with powder, such as a mold, etc.
A molding tool having only a side portion may be used, and the contact surface of the mold may also serve as the bottom surface.

[Wet heat treatment process]
The moist heat treatment step is a step of moistening and heating the powder after the filling step.
In the present invention, the "moisture heat treatment" refers to a method of heating an object in a high humidity atmosphere using saturated water vapor, superheated steam or the like as a heat medium.

Here, the method of heating the object in a high humidity atmosphere is not particularly limited as long as the heating temperature and relative humidity can be set, but examples include methods using devices such as a steam oven or an autoclave. Among these, it is preferable that the moist heat treatment step is a step of moist heat treating the powder using a steam oven.

Here, the moist heat treatment in the present invention is
A bonding process for bonding powder particles on the outer surface of the powder to each other;
a solidification process in which the bound powder particles are dried to solidify the powder particles;
This process combines the above.
That is, in a preferred embodiment of the present invention, there is no need to perform a separate drying step in addition to the moist heat treatment step.

In addition, in a preferred embodiment of the present invention, there is no step of compressing the powder between the filling step and the moist heat treatment step.

　We will explain the more preferable conditions for moist heat treatment.

The relative humidity in the wet heat treatment is preferably 10% or more, more preferably 15% or more, more preferably 20% or more, and more preferably 25% or more.
By subjecting the food to moist heat treatment under the above conditions, a solid food with higher solubility can be produced. Note that the term "relative humidity" used herein refers to the ratio (% RH) of the amount of water vapor present in the air to the amount required to make the air saturated at the same temperature, and is the value at the heating temperature during moist heat treatment.

The relative humidity in the moist heat treatment is preferably 100% or less, more preferably 90% or less, more preferably 80% or less, more preferably 70% or less, more preferably 60% or less, more preferably 50% or less, more preferably 40% or less, and even more preferably 30% or less.
By subjecting the food to moist heat treatment under the above conditions, a solid food with higher solubility can be produced.

The relative humidity in the moist heat treatment is preferably 10 to 100%, more preferably 10 to 80%, more preferably 10 to 70%, more preferably 10 to 60%, more preferably 10 to 50%, more preferably 10 to 40%, and even more preferably 10 to 30%.

The heating temperature in the moist heat treatment is preferably 80° C. or higher, more preferably 90° C. or higher, more preferably 100° C. or higher, more preferably 110° C. or higher, more preferably 120° C. or higher, more preferably 130° C. or higher.
By subjecting the food to moist heat treatment under the above conditions, a solid food with higher solubility can be produced.

The heating temperature in the wet heat treatment is preferably 180° C. or less, more preferably 170° C. or less, more preferably 160° C. or less, more preferably 150° C. or less, more preferably 145° C. or less, more preferably 140° C. or less.
By subjecting the food to moist heat treatment under the above conditions, a solid food with higher solubility can be produced.

The treatment time in the wet heat treatment is preferably 30 seconds or more, more preferably 40 seconds or more, more preferably 50 seconds or more, and more preferably 55 seconds or more.
By subjecting the food to moist heat treatment under the above conditions, a solid food with higher solubility can be produced.

The treatment time in the wet heat treatment is preferably 5 minutes or less, more preferably 4 minutes or less, more preferably 3 minutes or less, more preferably 2 minutes or less, more preferably 1.5 minutes or less.
By subjecting the food to moist heat treatment under the above conditions, a solid food with higher solubility can be produced.

Here, the degree of change in density from the powder before the moist heat treatment step to the solid food after the moist heat treatment step is expressed by the following formula (1).
Density change rate = (density of solid food) / (loose bulk density of powder before moist heat treatment process) ... (1)

The degree of density change from the powder before the moist heat treatment step to the solid food after the moist heat treatment step, represented by the above formula (1), is preferably 0.7 or more, more preferably 0.8 or more, more preferably 0.85 or more, more preferably 0.9 or more, more preferably 0.95 or more, and even more preferably 0.97 or more.
By subjecting the food to moist heat treatment under the above conditions, a solid food with higher solubility can be produced.

In addition, the rate of change in density from the powder before the moist heat treatment step to the solid food after the moist heat treatment step, represented by the above formula (1), is preferably 1.3 or less, more preferably 1.2 or less, more preferably 1.15 or less, more preferably 1.1 or less, and more preferably 1.05 or less.
By subjecting the food to moist heat treatment under the above conditions, a solid food with higher solubility can be produced.

<Solid Food>
Next, a more preferred embodiment of the solid food of the present invention will be described in detail, taking the above-mentioned production method as a production example.

First, we will show a preferred form for the composition of the solid food of the present invention.

In the present invention, it is preferable that the solid food contains lipids.

The lipid content in the solid food is preferably 10% by mass or more, more preferably 15% by mass or more, more preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 26.5% by mass or more, of the entire solid food.
The solid food in the above form has excellent solubility.

In addition, the lipid content in the solid food is preferably 50% by mass or less, more preferably 45% by mass or less, more preferably 40% by mass or less, more preferably 35% by mass or less, and more preferably 30% by mass or less, of the entire solid food.
The solid food in the above form has excellent solubility.

Here, when adjusted fat is contained as the lipid, the content of adjusted fat in the solid food is preferably 10% by mass or more, more preferably 15% by mass or more, more preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 26% by mass or more of the entire solid food.
The solid food in the above form has excellent solubility.

Furthermore, when modified fat is included as the lipid, the content of modified fat in the solid food is preferably 50% by mass or less, more preferably 45% by mass or less, more preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, of the entire solid food.
The solid food in the above form has excellent solubility.

Here, when milk fat is contained as lipid, the content of milk fat in the solid food is preferably 1 mass% or more, more preferably 3 mass% or more, more preferably 5 mass% or more, more preferably 10 mass% or more, more preferably 15 mass% or more, more preferably 25 mass% or more, and even more preferably 26 mass% or more of the total powder.
The solid food in the above form has excellent solubility.

Furthermore, when milk fat is contained as lipid, the milk fat content in the solid food is preferably 50% by mass or less, more preferably 45% by mass or less, more preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, of the entire solid food.
The solid food in the above form has excellent solubility.

In addition, in the present invention, it is preferable that the solid food contains carbohydrates.

The carbohydrate content in the solid food is preferably 30% by mass or more, more preferably 35% by mass or more, more preferably 40% by mass or more, more preferably 45% by mass or more, and more preferably 50% by mass or more of the entire solid food.
The solid food in the above form has excellent solubility.

In addition, the carbohydrate content in the solid food is preferably 80% by mass or less, more preferably 75% by mass or less, more preferably 70% by mass or less, more preferably 65% by mass or less, and even more preferably 60% by mass or less, of the entire solid food.
The solid food in the above form has excellent solubility.

Here, when lactose is contained as a carbohydrate, the lactose content in the solid food is preferably 30% by mass or more, more preferably 35% by mass or more, more preferably 40% by mass or more, more preferably 45% by mass or more, and more preferably 50% by mass or more of the entire solid food.
The solid food in the above form has excellent solubility.

Furthermore, when lactose is contained as a carbohydrate, the lactose content in the solid food is preferably 80% by mass or less, more preferably 75% by mass or less, more preferably 70% by mass or less, more preferably 65% by mass or less, more preferably 60% by mass or less, and even more preferably 55% by mass or less of the entire solid food.
The solid food in the above form has excellent solubility.

When sugars other than lactose are contained as carbohydrates, the content of sugars other than lactose in the solid food is preferably 1% by mass or more, more preferably 2% by mass or more, more preferably 3% by mass or more, and more preferably 4% by mass or more of the entire solid food.
The solid food in the above form has excellent solubility.

Furthermore, when sugars other than lactose are contained as carbohydrates, the content of sugars other than lactose in the solid food is preferably 10% by mass or less, more preferably 7% by mass or less, and more preferably 5% by mass or less of the entire solid food.
The solid food in the above form has excellent solubility.

In addition, in the present invention, it is preferable that the solid food contains protein.

The protein content in the solid food is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more, of the entire solid food.
The solid food in the above form has excellent solubility.

The protein content in the solid food is preferably 25% by mass or less, more preferably 20% by mass or less, and more preferably 15% by mass or less, of the entire powder.
The solid food in the above form has excellent solubility.

The above content can be used as a reference for preferred embodiments of the protein to be used here.

Furthermore, the water content of the solid food is preferably 5% by mass or less, more preferably 4% by mass or less, and more preferably 3% by mass or less.
Furthermore, the water content of the solid food is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, more preferably 1% by mass or more, and more preferably 2% by mass or more.
The solid food in the above form has excellent solubility.

Here, it is preferable that the total mass of lipids and carbohydrates in the solid food account for the largest proportion of the total mass of the solid food.
By increasing the lipid and carbohydrate content in a solid food, a more soluble solid food can be provided.

The lipid and carbohydrate content in the solid food is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 75% by mass or more, more preferably 80% by mass or more, and even more preferably 83% by mass or more.
By increasing the lipid and carbohydrate content in a solid food, a more soluble solid food can be provided.

Furthermore, the lipid and protein content in the solid food is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more.
By increasing the lipid and protein content in the solid content of a solid food, a more soluble solid food can be provided.

The mass ratio of lipids to carbohydrates in solid foods is preferably within the range of 1:0.5 to 1:4.0, more preferably 1:0.5 to 1:3.7, and more preferably 1:0.5 to 1:3.5.

Here, in a preferred embodiment of the present invention, the solid food is solid milk.

In a preferred embodiment of the solid food of the present invention, the density of the solid food is 0.6 g/ ^cm3 or less.

The density of the solid food is preferably 0.3 g/cm ³ or more, more preferably 0.35 g/cm ³ or more, and even more preferably 0.4 g/cm ³ or more.
By setting the density within the above range, it is possible to provide a solid food that has both high solubility and strength.

The density of the solid food is preferably 0.6 g/ ^cm3 or less, more preferably 0.55 g/cm3 or ^less , and even more preferably 0.5 g/cm3 ^or less.
By setting the density within the above range, a solid food with higher solubility can be provided.

Furthermore, the volume of the solid food is preferably 3 ^cm3 or more, more preferably 5 ^cm3 or more, more preferably 7 ^cm3 or more, more preferably 10 ^cm3 or more, and even more preferably 14 ^cm3 or more.
The volume of the solid food is preferably 30 ^cm3 or less, more preferably 25 ^cm3 or less, more preferably 20 ^cm3 or less, and more preferably 15 cm3 ^or less.
By using the above-mentioned form, it is possible to provide a solid food that has both high solubility and strength.

Here, the volume of the solid food can be a value measured using a VOLSCAN (laser).
In addition, the density of a solid food can be calculated based on the volume measured with a VOLSCAN (laser) and the weight.

Furthermore, the thickness of the solid food is preferably 0.5 cm or more, more preferably 1 cm or more, and even more preferably 1.5 cm or more.
Furthermore, the thickness of the solid food is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less.
By using the above-mentioned form, it is possible to provide a solid food that has both high solubility and strength.

In this embodiment, the three-dimensional shape of the solid food can be understood from the above explanation of the shape of the container.

The solid food of the present invention is characterized in that it has an outer surface that can be grasped.
In this specification, "having a grippable outer surface" means that the entire solid food has enough shape retention to be easily gripped with fingers, and the surface is formed to the extent that the solid food does not obviously stick to the fingers.

The solid food preferably has the following characteristics with respect to hardness under the following measurement conditions.
[Hardness Measurement]
The device used was a texture analyzer "TA.XT.plus" manufactured by Eiko Seiki Co., Ltd., and a spherical plunger with a diameter of 10 mm was inserted 5 mm into a sample of 1.9 cm x 1.9 cm x 2.0 cm height at room temperature at 1.0 mm/s, and the measured breaking strength was taken as the hardness.

Here, the hardness of the solid food at room temperature is preferably 5 kgf or less, more preferably 4.5 kgf or less, and more preferably 4 kgf or less.

The hardness of the solid food at room temperature is preferably 1 kgf or more, more preferably 1.5 kgf or more, more preferably 2 kgf or more, more preferably 2.5 kgf or more, more preferably 3 kgf or more, more preferably 3.5 kgf or more.
By using the above-mentioned form, it is possible to provide a solid food that has both high solubility and strength.

Furthermore, when a solid food is dropped into hot water at 60° C. to 70° C. so that the solute concentration is 3% by mass to 15% by mass, the solid food dissolves in the hot water.
In this specification, the phrase "a solid food dissolves in warm water" means that a dissolution test reveals that almost no dissolved residue remains.
More specifically, when 3 g to 8 g of a solid food is used and the solid food is dropped into hot water at 60°C to 70°C so as to give a solute concentration of 3% by mass to 15% by mass, the dissolved residue of the solid food is 0.2 g or less, preferably 0.15 g or less, and more preferably 0.1 g or less.

More specifically, the solid food produced by the above production method has a dissolved residue of 0.2 g or less, more preferably 0.15 g or less, and more preferably 0.1 g or less, under the following solubility measurement conditions.

[Solubility measurement conditions for solid foods containing adjusted fat]
Pour 55 g (55 mL) of 70° C. hot water into a beaker, add 8 g of solid food while stirring with a stirrer to make the solute concentration 13 wt %, and stir for 10 seconds.
Immediately after 10 seconds have elapsed, the entire content of the beaker is poured into a sedimentation tank and the mass [g] of the dissolved residue is measured.

[Solubility measurement conditions for solid foods containing milk fat]
Pour 100 g (100 ml) of 60°C hot water into a beaker, add 3.5 g of solid food while stirring with a stirrer to make the solute concentration 3.5 wt%, and stir for 30 seconds. Immediately after 30 seconds have passed, pour the entire content of the beaker into a sediment and measure the mass [g] of the dissolved residue.

<Method for improving the solubility of solid foods>
The present invention also relates to a method for improving the solubility of a solid food.
The method for improving the solubility of a solid food of the present invention comprises: filling a powder containing lipids and carbohydrates into a container;
The method includes a moist heat treatment step of moist heat treating the powder after the filling step under conditions of a relative humidity of 10% or more and a temperature of 80° C. or more.

In addition, in a preferred embodiment of the method for improving the solubility of solid foods, the filling step is a step of filling the container with the powder without compressing it, and does not include a step of compressing the powder between the filling step and the moist heat treatment step.

The above explanation can be used here as a preferred embodiment of the method for improving the solubility of solid foods of the present invention.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

<Powder Preparation>
The raw materials were mixed to obtain the composition shown in Table 1, and powder was prepared by a conventional method (spray drying method).
The particle size distribution of the prepared Powder A and Powder B was measured (see FIG. 1 and Table 1).
Here, the particle size distribution of Powder A was measured using a sieving method (mechanical shaking method).
The particle size distribution of Powder B was measured using a Mastersizer 3000 (Malvern Panalytical).

Test Example 1: Investigation of moist heat treatment conditions The moist heat treatment conditions were investigated using Powder B prepared above.

(1) Test Contents Powder B was formed into a flat plate and subjected to a moist heat treatment at a temperature of 140° C. with the relative humidity and heating time shown in Figure 2. The state of solidification was confirmed. The results are shown in Figure 2.

(2) Results With regard to the relative humidity, it was found that Powder B solidifies when the relative humidity is 10% or more, as shown in Fig. 2. It was also found that Powder B does not solidify when the relative humidity is 0%, as shown in Fig. 2.
As for the heating time, as shown in FIG. 2, it was found that powder B solidified under any condition as long as the relative humidity was 10% or more.

Test Example 2: Examination of density change due to moist heat treatment (1) Test details Using the powders A and B prepared above, a study was carried out on density change due to moist heat treatment.

(1-1) Filling step Powder was poured into a rectangular parallelepiped mold (corresponding to a container in the present invention) prepared in advance, and then the mold (corresponding to a container in the present invention) was lightly vibrated to level the powder. The powder protruding from the upper end of the mold was then leveled by scraping, so that the powder was filled into the mold without being compressed. The powder was not compressed between filling and the moist heat treatment.
The loose bulk density of the powder after the packing process was calculated (see Tables 2 and 3).

(1-2) Wet Heat Treatment Step Then, the resultant was subjected to wet heat treatment under the conditions shown in Tables 2 and 3.
The powder solidified by the moist heat treatment, and it was confirmed that it became a solid food with a grippable outer surface.
The density of rectangular solid food products after moist heat treatment was calculated.

As a reference example, the density of solid food C (containing protein, lipids (adjusted fat), and carbohydrates; total amount of protein, lipids, and carbohydrates: approximately 95% by mass), which is an existing product that has been subjected to compression molding of powder, was measured.
The measured density of solid food C was 0.71 g/ ^cm3 .
Here, the density of the solid food C was calculated based on the volume and weight measured by VOLSCAN (laser).

(2) Results The results are shown in Tables 2 and 3.

(3) Observations It was found that by filling the powder into a container and subjecting it to moist heat treatment in the above process, there is almost no change in density from the powder before the moist heat treatment process to the solid food after the moist heat treatment process.
More specifically, it was found that the degree of change in density (see formula (1) below) from the powder before the moist heat treatment step to the solid food after the moist heat treatment step was 0.8 or more and 1.2 or less.
Density change rate=(density of solid food)/(loose bulk density of powder before moist heat treatment process) (1).

Test Example 3: Examination of the physical properties of moist heat treated solid food (1) Test details Powder B prepared above was used to examine the physical properties of moist heat treated solid food.

(1-1) Filling step: After pouring the powder into a mold (corresponding to a container in the present invention) prepared in advance, the mold (corresponding to a container in the present invention) was lightly vibrated to level the powder. Then, the powder protruding from the upper end of the mold was leveled by scraping, so that the powder was filled into the mold without being compressed. The powder was not compressed between filling and the moist heat treatment.

(1-2) Wet heat treatment step Then, the mixture was subjected to wet heat treatment under the conditions shown in Table 4.
The powder solidified by the moist heat treatment, and it was confirmed that it became a solid food with a grippable outer surface.

(2) Results The results are shown in Table 4 and Figures 3 and 4.

(3) Observations As shown in Table 4 and Figs. 3 and 4, it was found that by filling a container with powder and subjecting it to moist heat treatment in the above process, solid milk (corresponding to the solid food in the present invention) with excellent solubility can be produced.
Specifically, the method includes filling a powder containing lipids and carbohydrates into a container;
It was found that by including a moist heat treatment step in which the powder after the filling step is moist heat treated under conditions of a relative humidity of 10% or more and a temperature of 80°C or more, solid milk (corresponding to the solid food in this invention) with excellent solubility can be produced.
In addition, regarding the filling process, it was found that by filling the container with the powder without compressing it and not going through a step of compressing the powder between the filling process and the moist heat treatment process, solid milk (corresponding to the solid food in this invention) with excellent solubility can be produced.

Test Example 4: Study on hardness of solid food by moist heat treatment (1) Test details Powder B prepared above was used to study the hardness of solid food subjected to moist heat treatment.

(1-1) Filling step Powder B was poured into a previously prepared mold (corresponding to a container in the present invention), and the mold (corresponding to a container in the present invention) was gently vibrated to level the powder. The powder protruding from the upper end of the mold was then leveled by scraping, so that the powder was filled into the mold without being compressed. The powder was not compressed between filling and the moist heat treatment.

(1-2) Wet Heat Treatment Step Thereafter, the film was subjected to wet heat treatment under conditions of a temperature of 130° C., a relative humidity of 10%, and a time of 1 minute.
It was confirmed that the powder was solidified by the moist heat treatment to become a solid food having a grippable outer surface. The hardness of the solid food after the moist heat treatment was measured under the following measurement conditions.
[Hardness Measurement]
The device used was a texture analyzer "TA.XT.plus" manufactured by Eiko Seiki Co., Ltd., and a spherical plunger with a diameter of 10 mm was inserted 5 mm into a sample of 1.9 cm x 1.9 cm x 2.0 cm height at room temperature at 1.0 mm/s, and the measured breaking strength was taken as the hardness.

As a reference example, the hardness of solid food C (containing protein (adjusted fat), lipids, and carbohydrates; total amount of protein, lipids, and carbohydrates: approximately 95% by mass) which is an existing product that has been subjected to compression molding of powder, was measured.
The measured hardness of solid food C was 6 kgf or more (above the measurement limit).

(2) Results and Discussion The results are shown in Table 5.

As shown in Table 5, it was found that by filling a container with powder using the above process and subjecting it to moist heat treatment, a solid food with low hardness can be produced. Furthermore, it was found that solid foods with a hardness below a certain value produced using the above process have excellent solubility.

<Test Example 5> Examination of differences in solubility of solid foods due to differences in manufacturing methods (1) Test details The difference in solubility was examined between solid food B manufactured using powder B prepared as described above and solid food C (containing protein, lipids (adjusted fat), and carbohydrates; total amount of protein, lipids, and carbohydrates: approximately 95% by mass), which is an existing product made by compressing and molding the powder.

(1-1) Production of solid food B (i) Filling step Powder A or powder B was poured into a previously prepared mold (corresponding to a container in the present invention), and the mold (corresponding to a container in the present invention) was gently vibrated to level the powder. Thereafter, the powder protruding from the upper end of the mold was leveled by scraping, so that the powder was filled into the mold without being compressed. The powder was not compressed between filling and the moist heat treatment.

(ii) Wet Heat Treatment Step Thereafter, the film was subjected to wet heat treatment under conditions of a temperature of 130° C., a relative humidity of 30%, and a time of 1 minute.
The powder solidified by the moist heat treatment, and it was confirmed that it became a solid food with a grippable outer surface.

(1-2) Comparative Observation The solubility of solid food A produced using powder A, solid food B produced using powder B, and solid food C (containing protein, lipid (adjusted fat), and carbohydrate; total amount of protein, lipid, and carbohydrate: approximately 95% by mass) which is an existing product produced by compression molding of powder, was evaluated under the following conditions.
The solubility was evaluated by visual observation by an evaluator who is an expert in the production of solid foods.

[Solubility measurement conditions]

(i) Solid food A, solid food C
Pour 55 g (55 mL) of 70°C hot water into a beaker, add 8 g of solid food while stirring with a stirrer to make the solute concentration 13% by weight, and stir for 10 seconds. Immediately after 10 seconds have passed, The entire content is subjected to sedimentation and the mass [g] of the dissolved residue is measured.
After passing the sediment through the separator, suction was continued for 1 minute.

(ii) Solid food B
Pour 100 g (100 ml) of 60° C. hot water into a beaker, add 3.5 g of solid food while stirring with a stirrer to make the solute concentration 3.5 wt %, and stir for 30 seconds.

(2) Results and Observations As a result of visual evaluation and measurement by an evaluator who is an expert in the manufacture of solid foods, no dissolved residues could be visually confirmed in the test systems for solid food A and solid food B.
Furthermore, as a result of visual evaluation and measurement by an evaluator who is specialized in the manufacture of solid foods, solid food A was clearly superior in solubility to solid food C. Specifically, while dissolved residues could be visually confirmed in the test system of solid food C, dissolved residues could not be visually confirmed in the test system of solid food A.

Here, for solid food A, immediately after 10 seconds had elapsed, the entire content of the beaker was poured into a sedimentation tank and the mass [g] of the dissolved residue was measured, which was found to be 0 g.
On the other hand, in the case of solid food C, the dissolved residue was 0.2 g or more (n=3, Sample No. 1: 0.33 g, Sample No. 2: 0.24 g, Sample No. 3: 0.5 g) (see FIG. 5).

The present invention can be applied to the production of solid foods.

Claims (14)

1. A method for producing a solid food product, comprising the steps of:
   A filling step of filling a container with a powder containing lipids and carbohydrates;
   a moist heat treatment step of subjecting the powder after the filling step to moist heat treatment under conditions of a relative humidity of 10% or more and a temperature of 80° C. or more;
   A method for producing a solid food product comprising:
2. The filling step is a step of filling the powder into a container without compressing the powder,
   The powder is not compressed between the filling step and the moist heat treatment step.
   A method for producing the solid food product according to claim 1.
3. The moist heat treatment step is a step of moist heat treating the powder using a steam oven.
   A method for producing the solid food according to claim 1 or 2.
4. The moist heat treatment step includes:
   A bonding process for bonding powder particles on the outer surface of the powder to each other;
   a solidification process in which the bound powder particles are dried to solidify the powder particles;
   The method for producing a solid food according to claim 1 or 2, wherein the step of:
5. The method for producing a solid food according to claim 1 or 2, wherein the moist heat treatment step is a step of moist heat treating the powder after the filling step under conditions of a relative humidity of 10% to 100% and a temperature of 120°C or higher.
6. 3. The method for producing a solid food according to claim 1 or 2, wherein the powder has a loose bulk density of 0.6 g/ ^cm3 or less before the moist heat treatment step.
7. 3. The method for producing a solid food according to claim 1, wherein the density of the solid food after the moist heat treatment step is 0.6 g/cm3 or ^less .
8. The method for producing a solid food according to claim 1 or 2, wherein the particle size distribution of the powder satisfies at least one of the following conditions (A) to (D):
   (A) particles having a particle diameter of 125 μm or more account for 50% by mass or more and 90% by mass or less;
   (B) particles having a particle size of 125 μm or more and less than 250 μm account for 25% by mass or more and 60% by mass or less;
   (C) 90% by mass or more of particles having a particle diameter of 75 μm or more;
   (D) The content of particles having a particle diameter of less than 425 μm is preferably 98% by mass or less.
9. 3. The method for producing a solid food according to claim 1 or 2, wherein a density change rate from the powder before the moist heat treatment step to the solid food after the moist heat treatment step, represented by the following formula (1), is 0.8 to 1.2.
   Density change rate = (density of solid food) / (loose bulk density of powder before moist heat treatment process)
10. A powder containing lipids and carbohydrates,
    a solid food product having a graspable outer surface,
    A solid food product, wherein the density of the solid food product is 0.6 g/cm3 ^or less.
11. The solid food according to claim 10, wherein the solid food dissolves in hot water at 60°C to 70°C when the solid food is dropped into the hot water so that the solute concentration is 3% to 15% by mass.
12. The solid food according to claim 10 or 11, wherein the solid food has a hardness of 1 kgf or more and 5 kgf or less under the following hardness measurement conditions:
    [Hardness Measurement]
    The device used was a texture analyzer "TA.XT.plus" manufactured by Eiko Seiki Co., Ltd., and a spherical plunger with a diameter of 10 mm was inserted 5 mm into a sample of 1.9 cm x 1.9 cm x 2.0 cm height at room temperature at 1.0 mm/s, and the measured breaking strength was taken as the hardness.
13. A method for improving the solubility of a solid food, comprising the steps of:
    A filling step of filling a container with a powder containing lipids and carbohydrates;
    The method for improving the solubility of a solid food includes a moist heat treatment step of subjecting the powder after the filling step to moist heat treatment under conditions of a relative humidity of 10% or more and a temperature of 80°C or more.
14. The filling step is a step of filling the powder into a container without compressing the powder,
    The powder is not compressed between the filling step and the moist heat treatment step.
    The method for improving the solubility of a solid food according to claim 13.
    
    

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