CN116056583A - Solid food and solid milk - Google Patents

Abstract

To provide a solid food and a solid milk which have improved adhesion and have strength for easy handling. The solid food is obtained by compression molding of food powder, and has a breaking stress of 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

Description

Solid food and solid milk

Technical Field

The present invention relates to solid food and solid milk.

Background

As solid foods, solid milk obtained by compression molding of powdered milk is known (see patent documents 1 and 2). The solid milk is required to have a solubility that is rapid to dissolve by being put into warm water and a breakage resistance that is suitable for transportation, that is, a property that is not broken or broken during transportation or carrying.

As a tablet press for compression molding of food powder typified by powdered milk, a tablet press is known in which a slide plate having 2 die holes is reciprocated in the horizontal direction (see patent document 3).

Prior art literature

Patent literature

Patent document 1: japanese patent No. 5350799

Patent document 2: japanese patent No. 5688020

Patent document 3: japanese patent laid-open No. 2007-307592

Disclosure of Invention

Problems to be solved by the invention

The force required for peeling the solid food or the solid milk when the solid food or the solid milk is attached to a manufacturing apparatus or the like is called an adhesive force.

It is desirable to compress a food powder or a milk powder into a solid food or a solid milk having an easy-to-handle strength and further improved adhesion.

The present invention aims to provide solid food and solid milk with improved adhesion and strength for easy handling.

Solution for solving the problem

The solid food of the present invention is a solid food obtained by compression molding of a food powder, and has a breaking stress of 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

The solid milk of the present invention is a solid milk obtained by compression molding of powdered milk, and has a breaking stress of 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the solid food is a solid food obtained by compression molding of a food powder, and the breaking stress of the solid food is 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² . The peel shear stress is a value obtained by dividing the adhesion force by the peel area. The solid food has improved adhesion and easy handling strength.

In addition, according to the present invention, the milk powder is solid milk obtained by compression molding of milk powder, and the breaking stress of the solid milk is 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² . The solid milk has improved adhesion and has easy handling strength.

Drawings

Fig. 1 is a perspective view of solid milk according to embodiment 1.

Fig. 2 is a cross-sectional view of the solid milk of fig. 1 along the direction X1-X2.

Fig. 3 is a cross-sectional view of the solid milk of fig. 1 in the direction Y1-Y2.

Fig. 4 is an explanatory diagram for explaining positions of a slide plate, an upper punch, and a lower punch of the tablet press.

Fig. 5 is an explanatory diagram for explaining the positions of the upper punch and the lower punch at the start of the 1 st compression.

Fig. 6 is an explanatory diagram for explaining positions of the upper punch and the lower punch after the 1 st compression is completed and at the start of the 2 nd compression.

FIG. 7 is a graph showing the ratio of increase in crystallization rate of the surface of the solid milk of the example, β/(α+β), to the breaking stress (N/mm) of the solid milk ² ) Is a graph of the relationship of (1).

FIG. 8 is a graph showing the ratio of increase in crystallization rate of the surface of the solid milk of the example, β/(α+β), to the peel shear stress of the solid milk (N/mm ² ) Is a graph of the relationship of (1).

Detailed Description

Hereinafter, embodiments of the present invention will be described. However, the manner described below is merely an example, and may be suitably modified within the scope of the present invention as will be apparent to those skilled in the art.

Embodiment 1

(constitution of solid milk 10S)

Fig. 1 is a perspective view of solid milk 10S of the present embodiment. Fig. 2 is a cross-sectional view of the solid milk 10S of fig. 1 along the direction X1-X2. Fig. 3 is a cross-sectional view of the solid milk 10S of fig. 1 in the direction Y1-Y2.

The solid milk 10S has a solid body 10 obtained by compression molding of powdered milk. The main body 10 has: a 1 st plane 10A which is parallel to the XY plane and flat, and a 2 nd plane 10B which is parallel to the XY plane and flat. The 1 st face 10A and the 2 nd face 10B are back-to-back faces. The shape of the body 10 is determined by the shape of a die (die of a tablet press) used in compression molding, but is not particularly limited as long as it has a certain size (size, thickness, angle). The main body 10 has an overall shape of a cylinder, an elliptic cylinder, a cube, a rectangular parallelepiped, a plate, a polygonal column, a polygonal pyramid, a polyhedron, or the like. From the viewpoints of ease of molding, convenience of transportation, and the like, a cylindrical shape, an elliptic cylindrical shape, and a rectangular parallelepiped shape are preferable. The main body 10 of the solid milk 10S shown in fig. 1 to 3 has a rectangular parallelepiped shape with dimensions a×b×c (see fig. 1), and the main body 10 has a side surface 10C parallel to the XZ plane or parallel to the YZ plane. The corners formed by the 1 st surface 10A and the side surface 10C and the corners formed by the 2 nd surface 10B and the side surface 10C may have a tapered shape to be chamfered, respectively. When chamfered, the breakage of the solid milk 10S can be suppressed at the time of transportation or the like.

The surface is the surface forming the outside of the substance. The surface layer is a layer near the surface including the surface. For example, the surface layer is a layer formed by compression molding of powdered milk, and further hardened by a hardening treatment. The surface layer of the present embodiment is a harder layer than the inside. Here, the surface layer is a layer harder than the inside, and means: the force required to separate only the skin layer is relatively greater than the force required to separate the interior.

The solid milk 10S of the present embodiment is a solid milk obtained by compression molding and hardening of powdered milk, and has a breaking stress of 0.067N/mm ² The above. Here, the peel shear stress for a flat face is greater than 0.015N/mm ² . The size of the solid milk 10S of the present embodiment is 0.015N/mm as follows ² The peel shear stress of (2) was converted to an adhesion of 6N.

The adhesion force of the solid milk 10S of the present embodiment described above to the flat surface is greater than 6N. The adhesion force of the solid milk adhering to the contact surface of the manufacturing apparatus such as the belt conveyor in the manufacturing process is increased, and thus, even if the conveying speed of the solid milk is increased, the solid milk can be suppressed from being blown off, the solid milk can be stably conveyed, and the manufacturing efficiency can be improved. Here, adhesion means: in the process of producing solid milk, when hardening treatment is performed on a flat surface such as a perforated screen, the solid milk adheres to the flat surface, and the force (load) required for peeling the solid milk from the flat surface [ N ]. Specifically, the non-cured milk powder compression molded product was placed on a perforated sieve (Nunobiki Manufacturing co., ltd., manufactured by ltd., material SUS304, plate thickness of 1.5mm, pore diameter of 2.5mm, pore center spacing of 3.0mm to 3.5mm, and perforated sieve opening area ratio of 45 to 47%), and cured to obtain solid milk. The solid milk is in a state where only the bottom surface is attached to the perforated screen. Next, a load was applied to a terminal of a load measuring device (a load cell type tablet hardness tester (portable tester PC-30) manufactured by okang Tian Jinggong corporation) on a side surface of the solid milk on the perforated screen immediately after the hardening treatment, and a load required for peeling the solid milk from the perforated screen was measured. Here, the perforated screen was fixed in a state where 3 surfaces of the bottom surface, the long side surface, and the short side surface were in contact with the load measuring device. In the solid milk, the 2 nd surface 10B of the solid milk 10S is used as the bottom surface, and only the bottom surface is attached to the perforated screen, and the distance between the side surface of the solid milk pressed by the breaking terminal of the durometer (one surface parallel to the XZ plane of the side surface 10C) and the wall surface of the load measuring device, which is a pair of opposite side surfaces, is set to 5mm. The fracture terminals built in the durometer have contact surfaces with the solid milk 10S, not with the perforated screen. The contact surface of the breaking terminal is a rectangle of 1mm×24mm, and the long axis of the rectangle is arranged in a direction parallel to the Z axis. The contact surface of the broken terminal is configured to at least partially press the measurement point of the solid milk 10S. The speed at which the broken terminal presses the solid milk 10S with the broken terminal was set to 0.5mm/S along the short axis direction (Y-axis direction in fig. 1) of the 1 st face 10A from one face side of the side face 10C parallel to the XZ plane. The solid milk 10S is pressed by the broken terminal, and the maximum load [ N ] at the time of peeling from the perforated screen is taken as the adhesion [ N ] of the solid milk 10S.

The term "peeling" herein means peeling when a static load is applied to a sample such as the solid milk 10S. Adhesion [ N ]]Is a physical quantity independent of the size of the solid milk sample. As a physical quantity independent of the size of the solid milk sample, there is a peel shear stress [ N/m ] ² ]. The peel shear stress is an index that can compare the mechanical action applied to solid milk samples even between solid milk samples having different sizes, regardless of the size of the solid milk sample, and is a force applied per unit peel area at the time of peeling. As peel shear stress = adhesion/peel area. In the present specification, the adhesion [ N ] is sometimes used simply]These may be expressed as peel shear stress [ N/m ] divided by the peel area ² ]. In calculating the peel shear stress, the peel area is used for calculation. For example, in the case of solid milk 10S, the peeling area is the area of contact between 10S and the perforated screen, which is the product of the bottom area of 10S of 31mm×24mm and the ratio of contact between the perforated screen and 10S, i.e., 0.54 (46% of the opening ratio of the perforated screen, and therefore the ratio of contact between the perforated screen and 10S is 1 to 0.46=0.54), and is represented by the following equation (peeling area (mm ² ) = [ bottom area of molded body (mm) ² ) X (1-ratio of openings of punching sieve)])。

For example, in the case of a rectangular parallelepiped shape having a total shape of solid milk 10S of 31mm (a). Times.24 mm (b). Times.12.5 mm (c), the peeling area is 402mm ² (31 mm (a). Times.24 mm (b)). Times.1-0.46. The range of adhesion of the solid milk 10S greater than 6N corresponds to the adhesion divided by the peeling area (402 mm ² ) And the obtained concentration is more than 0.015N/mm ² Is not limited by the peel shear stress. Considering the range of the peeling area, the peeling shear stress of the solid milk 10S is more than 0.015N/mm ² 。

The peel shear stress is preferably greater than 0.015N/mm ² More preferably 0.020N/mm ² The above, more preferably 0.025N/mm ² Above mentionedAnd more preferably 0.030N/mm ² The above. The peel shear stress is preferably greater than 6N, more preferably 8N or more, still more preferably 10N or more, and still more preferably 12N or more, in terms of adhesion force, in the case of the size of the solid milk 10S of the present embodiment.

As described above, if the adhesion is in the above range, the effect of improving the manufacturing efficiency described later can be obtained.

The solid milk of the present embodiment described above preferably contains an alpha lactose crystal and a beta lactose crystal, and the difference in the ratio of the alpha lactose crystal to the total weight of the surface of the solid milk and the ratio of the alpha lactose crystal inside the solid milk is an increase in crystallization rate of alpha (wt%); the difference between the ratio of β lactose crystals on the surface of the solid milk relative to the total weight and the ratio of β lactose crystals inside the solid milk is the increase β (wt%) in crystallization rate, and when the increase ratio β/(α+β) in crystallization rate is Xb, and the peel shear stress of the solid milk to a flat surface is Yb (N), the Xb and Yb satisfy the following formula (1) as the increase ratio β/(α+β) in crystallization rate of the sum of the increase β (wt%) in crystallization rate and the increase β (wt%) in crystallization rate.

0.1326Xb-0.0013＜Yb＜0.1326Xb+0.0087…(1)

The solid milk of the present embodiment is preferably such that the increase ratio β/(α+β) of the crystallization rate is 0.3 or less. The increase ratio β/(α+β) of the crystallization rate is preferably 0.25 or less, more preferably 0.2 or less, and still more preferably 0.15 or less. The increase ratio β/(α+β) of the crystallization rate is preferably 0 or more, more preferably 0.05 or more, still more preferably 0.065 or more, and still more preferably 0.08 or more.

The total crystallization rate is the ratio of crystals (wt%) to the total weight. Summarizing the increase in crystallization rate is defined as: the difference obtained by subtracting the crystallization rate of the crystal existing before the hardening treatment from the crystallization rate of the sum of the crystal existing before the hardening treatment and the crystal added in the hardening treatment according to the size affected by humidification. The crystallization rate of the crystals existing before the hardening treatment corresponds to the crystallization rate of the crystals in the solid milk which is not or substantially not affected by humidification in the present embodiment by the hardening treatment. That is, the increase in the total crystallization rate is a difference between the ratio of crystals at each depth from the surface of the solid milk relative to the total weight and the ratio of crystals inside the solid milk. Examples of the crystals include an alpha lactose crystal as a monohydrate crystal of lactose and a beta lactose crystal as an anhydrate crystal of lactose, and the increase in the crystallization rate of the alpha lactose crystal and the crystallization rate of the beta lactose crystal are defined in the same manner as described above. The sum (α+β) of the increase in the crystallization rate of the α lactose crystal and the increase in the crystallization rate of the β lactose crystal is the total crystallization rate increase.

The increase in the crystallization rate of the alpha lactose crystals, alpha (wt.%) is: the difference after subtracting the crystallization rate of the alpha lactose crystals existing before the self-hardening treatment from the crystallization rate of the sum of the alpha lactose crystals existing before the self-hardening treatment and the alpha lactose crystals increased according to the size of the influence of humidification in the hardening treatment. The crystallization rate of the α lactose crystals existing before the self-hardening treatment corresponds to the crystallization rate of the α lactose crystals in the solid milk which is not or substantially not affected by humidification in the present embodiment in the hardening treatment. That is, the increase in the crystallization rate of the alpha lactose is a difference between the ratio of the alpha lactose crystals at each depth from the surface of the solid milk relative to the total weight and the ratio of the alpha lactose crystals in the interior of the solid milk.

The increase in the crystallization rate of the β lactose crystals β (wt.%) is: the difference obtained by subtracting the crystallization rate of the β lactose crystals existing before the self-hardening treatment from the crystallization rate of the sum of the β lactose crystals existing before the self-hardening treatment and the β lactose crystals increased according to the size of the influence of humidification during the hardening treatment. The crystallization rate of the β lactose crystals existing before the self-hardening treatment corresponds to the crystallization rate of the β lactose crystals in the solid milk which is not or substantially not affected by humidification in the present embodiment in the hardening treatment. That is, the increase in the crystallization rate of β lactose is: differences in the ratio of beta lactose crystals relative to the total weight at various depths of the solid milk from the surface and the ratio of beta lactose crystals inside the solid milk.

The above-described increase in the crystallization rate of the surface of the solid milk is an increase in the crystallization rate obtained for a measurement region including the surface. The measurement region may be appropriately selected when the increase in the crystallization rate is measured.

The inside of the solid milk is a region where the total crystallization rate does not change or does not substantially change before and after the hardening treatment, for example, a center portion or a portion near the center of the solid milk. Specifically, the range is a cubic range of ±1mm from the center of the solid milk in the XYZ direction, or a spherical range of 1mm from the center radius of the solid milk. The hardening treatment is a treatment for hardening the milk powder compression molded product when producing solid milk, and details thereof will be described later.

The above description has been made with respect to the case where the region where the total crystallization rate does not change or substantially does not change before and after the hardening process, for example, the center portion or the vicinity of the center of the solid milk is referred to as the inside of the solid milk, but whether or not the total crystallization rate changes before and after the hardening process, the region may be the center portion or the vicinity of the center of the solid milk alone.

The increase in the total crystallization rate can be determined as follows: for example, by XRD (X-ray diffraction) method, the total crystallization rate of the entire surface was obtained by cutting the surface by an amount of 0.1mm each time the XRD of the measurement surface of the sample was measured. In the XRD measuring device capable of two-dimensional mapping, the increase in total crystallization rate can be measured with accuracy of, for example, about 0.05mm to 0.1mm in the depth direction of the sample.

The body 10 may have 1 or 2 or more holes extending from the 1 st surface 10A to the 2 nd surface 10B and penetrating the body 10. The shape of the aperture is oblong, rounded rectangle, oval, circular, rectangular, square, or other polygonal shape in a cross-section parallel to the XY plane, for example. The positions of the holes are preferably positions having no large deviation when viewed from the center position of the 1 st surface 10A, and are, for example, arranged in point symmetry with respect to the center position of the 1 st surface 10A, or arranged in line symmetry with respect to a line parallel to the X axis or a line parallel to the Y axis passing through the center of the 1 st surface 10A. When the number of holes is one, for example, the hole is provided in the center of the 1 st surface 10A. When the holes are provided, the edges of the holes may be beveled in a conical shape. When the hole is provided, the inner wall surface of the hole is a harder surface than the inside as in the 1 st surface 10A.

The composition of the solid milk 10S is substantially the same as that of the milk powder as the raw material. The components of the solid milk 10S are, for example, fat, protein, sugar, minerals, vitamins, moisture, and the like.

Milk powder is produced from liquid milk (liquid milk) containing milk components (e.g., components of milk). The milk component is, for example, raw milk (whole milk), skim milk, cream oil, or the like. The moisture content of the liquid milk is, for example, 40 to 95 wt%. The moisture content of the milk powder is, for example, 1 to 5% by weight. The milk powder may contain the following nutrients. The milk powder may be whole milk powder, skimmed milk powder or cream powder as long as it is suitable for the manufacture of solid milk 10S. The fat content of the milk powder is preferably, for example, 5 to 70% by weight.

The milk component that becomes the raw material of the milk powder described above is derived from, for example, raw milk. Specifically, the milk is raw milk derived from cows (cows in the netherlands, zebra Niu Chong, etc.), goats, sheep, buffalo, etc. The raw milk may be milk in which the fat content is adjusted by removing a part or all of the fat components by centrifugation or the like, while the fat components are contained in the raw milk.

The milk component that is the raw material of the milk powder is, for example, plant milk derived from plants. Specifically, the plant source is derived from soybean milk, rice milk, coconut milk, almond milk, hemp seed milk, peanut milk, and the like. The vegetable milk may be milk in which the fat content is adjusted by removing a part or all of the fat components contained in the milk by centrifugation or the like.

The nutritional ingredients of the raw materials of the milk powder are, for example, fat, protein, sugar, minerals, vitamins, and the like. One or two or more of these may be added.

Examples of proteins which can be used as a raw material of the milk powder include milk proteins and milk protein fractions, animal proteins, vegetable proteins, peptides and amino acids having various chain lengths which are decomposed by enzymes and the like. One or two or more of these may be added. Milk proteins are, for example, casein, whey proteins (alpha-lactalbumin, beta-lactoglobulin, etc.), whey Protein Concentrates (WPC), whey Protein Isolates (WPI), etc. The animal protein is egg protein, for example. Vegetable proteins are, for example, soy proteins and wheat proteins. Amino acids are, for example, taurine, cystine, cysteine, arginine, glutamine, and the like.

The fats (oils) which can be used as the raw materials of the above-mentioned milk powder are animal oils and fats, vegetable oils and fats, separated oils, hydrogenated oils and transesterified oils of these. One or two or more of these may be added. Animal fats and oils are, for example, milk fat, lard, tallow, fish oil, and the like. Vegetable oils and fats are, for example, soybean oil, rapeseed oil, corn oil, coconut oil, palm kernel oil, safflower oil, cottonseed oil, linseed oil, MCT (Medium Chain Triglyceride, medium chain fatty acid triglyceride) and the like.

Examples of the sugar that can be used as a raw material of the milk powder include oligosaccharides, monosaccharides, polysaccharides, and artificial sweeteners. One or two or more of these may be added. Examples of oligosaccharides are lactose, sucrose, maltose, galacto-oligosaccharides, fructo-oligosaccharides, lacto-ketose and the like. The monosaccharides include, for example, glucose, fructose, galactose, etc. Examples of the polysaccharides include starch, soluble polysaccharides, and dextrins. The artificial sweetener may be a non-sugar artificial sweetener instead of or in addition to sugar artificial sweetener.

Minerals which can be used as the raw material of the milk powder are, for example, sodium, potassium, calcium, magnesium, iron, copper, zinc, etc. One or two or more of these may be added. One or both of phosphorus and chlorine may be used instead of or in addition to the minerals sodium, potassium, calcium, magnesium, iron, copper, and zinc.

The solid milk 10S has a plurality of pores (for example, pores) formed when the powdered milk as a raw material of the solid milk 10S is compressed and molded. These plural voids are dispersed (distributed) corresponding to the filling rate distribution in the depth direction of the solid milk 10S. The larger (wider) the pores, the more likely the solvent such as water is to intrude, and thus the solid milk 10S can be rapidly dissolved. On the other hand, if the pores are too large, the hardness of the solid milk 10S may be weakened or the surface of the solid milk 10S may be roughened. The size (dimension) of each pore is, for example, 10 μm to 500. Mu.m.

The solid milk 10S needs to have a certain degree of solubility in a solvent such as water. For example, when preparing the solid milk 10S as a solute and water as a solvent so as to have a predetermined concentration, the solubility can be evaluated by the time required for the solid milk 10S to completely dissolve or the undissolved residual amount in a predetermined time.

The solid milk 10S preferably has a hardness in a prescribed range. The hardness can be measured by a known method. In this specification, the hardness is measured using a load cell type tablet durometer. The solid milk 10S was placed on a load cell type tablet hardness tester with the 2 nd surface 10B of the solid milk 10S formed into a rectangular parallelepiped shape as the bottom surface, the solid milk 10S was fixed to the XZ plane by using the 1 st surface of the side surface 10C and the 1 st surface parallel to the YZ plane, and the other surface side of the side surface 10C, which was not fixed, parallel to the XZ plane was pressed at a constant speed toward the YZ plane as a fracture surface along the short axis direction (Y axis direction in fig. 1) of the 1 st surface 10A by a fracture terminal of the hardness tester, and the load [ N ] at the time of fracture of the solid milk 10S was regarded as the hardness (tablet hardness) [ N ] of the solid milk 10S. In the case of the solid milk 10S, the measurement point is selected from points equidistant from the 1 st and 2 nd faces 10A and 10B on a line segment intersecting the XZ plane of the side face 10C on a plane parallel to the YZ plane equidistant from the pair of YZ planes of the side face 10C. For example, a load cell type tablet durometer (portable tester PC-30) manufactured by Kagaku Tian Jinggong Co., ltd. The breaking terminals built in the durometers have contact surfaces with the solid milk 10S. The contact surface of the breaking terminal is a rectangle of 1mm×24mm, and the long axis of the rectangle is arranged in a direction parallel to the Z axis. The contact surface of the broken terminal is configured to at least partially press the measurement point of the solid milk 10S. The speed at which the broken terminal pressed the solid milk 10S was set to 0.5mm/S. The measurement of the hardness is not limited to the solid milk 10S, but can be applied to the case of measuring the hardness of a milk powder compression molded product (unhardened solid milk 10S) described later. In order to avoid the situation where the solid milk 10S breaks during transportation of the solid milk 10S as much as possible, the hardness of the solid milk 10S is preferably 20N or more, more preferably 40N or more. On the other hand, if the hardness of the solid milk 10S is too high, the solubility of the solid milk 10S is poor, and therefore the hardness of the solid milk 10S is preferably 130N or less.

Hardness as used herein is a hardness having [ N (Newton)]Physical quantity of force per unit of (a). The hardness increases with increasing fracture area of the solid milk sample. Here, "break" means breakage when a static vertical load is applied to a sample such as solid milk 10S, and the cross-sectional area generated when the breakage occurs is referred to as "breaking area". Namely, hardness [ N ]]Is a physical quantity that depends on the size of the solid milk sample. As a physical quantity independent of the size of the solid milk sample, there is a breaking stress [ N/m ] ² ]. The breaking stress is a force applied per unit breaking area at the time of breaking, and is an index that enables the mechanical action of solid milk samples to be compared even between solid milk samples different in size, regardless of the size of the solid milk sample. Becomes fracture stress = hardness/fracture area. In the present specification, the hardness [ N ] may be used simply]These are described as fracture stresses [ N/m ] obtained by dividing the hardness by the fracture area ² ]. In calculating the fracture stress, fracture surfaces are assumed and calculated using the minimum fracture area in the assumed fracture surfaces. For example, in the case of solid milk 10S, the ideal fracture area is represented by dimension b×c, which is the fracture area in a plane including a line passing through the center of the solid milk and parallel to the Z-axis. For example, when the overall shape of the solid milk 10S is a rectangular parallelepiped with dimensions of 31mm (a) ×24mm (b) ×12.5mm (c), the ideal breaking area is 300mm ² (24 mm (b). Times.12.5 mm (c)). The preferred hardness range of 20N above and 130N below of the solid milk 10S corresponds to hardness divided by area of break (300 mm ² ) And 0.067N/mm ² Above and 0.43N/mm ² The following preferred fracture stress ranges. For example, a solidThe preferred range of breaking stress of the milk 10S is 0.067N/mm if considering the range of breaking area ² The above. In addition, it is preferably 0.961N/mm ² The following is given.

(method for producing solid milk 10S)

Next, a method for producing the solid milk 10S will be described. First, milk powder, which is a raw material of the solid milk 10S, is produced. In the process for producing powdered milk, powdered milk is produced by, for example, a liquid milk production process, a liquid milk clarification process, a sterilization process, a homogenization process, a concentration process, a gas dispersion process, and a spray drying process.

The liquid milk preparing step is a step of preparing liquid milk of the above components.

The clearing process is a process for removing fine foreign matters contained in the liquid milk. For removing the foreign matter, for example, a centrifuge, a filter, or the like may be used.

The sterilization step is a step for killing microorganisms such as bacteria contained in water, milk components, and the like of the liquid milk. The microorganisms that are considered to be actually contained vary according to the type of liquid milk, and thus the sterilization conditions (sterilization temperature, retention time) are appropriately set according to the microorganisms.

The homogenization process is a process for homogenizing liquid milk. Specifically, the particle size of solid components such as fat globules contained in liquid milk is reduced, and they are uniformly dispersed in liquid milk. In order to reduce the particle size of the solid component of the liquid milk, the liquid milk may be pressed through a narrow gap.

The concentration step is a step for concentrating the liquid milk before a spray drying step described later. The concentration of the liquid milk may be performed by using, for example, a vacuum evaporator or a rotary evaporator. The concentration conditions are appropriately set so as not to excessively deteriorate the components of the liquid milk. Thereby, concentrated milk can be obtained from liquid milk. Next, in the present invention, it is preferable to disperse a gas in concentrated liquid milk (concentrated milk) and spray-dry the same. In this case, the water content of the concentrated milk is, for example, 35 to 60 wt%, preferably 40 to 60 wt%, and more preferably 40 to 55 wt%. When such a concentrated milk dispersion gas is used, the concentrated milk in such a state that the volume is increased by decreasing the density of the concentrated milk is spray-dried, whereby milk powder having preferable characteristics can be obtained when solid milk is produced. When the water content of the liquid milk is small and the processing amount of the liquid milk to be subjected to the spray drying process is small, the process may be omitted.

The gas dispersing step is a step for dispersing a predetermined gas in liquid milk. In this case, the predetermined gas may be, for example, 1×10 in volume of liquid milk ^-2 Dispersing the milk in a volume of more than 7 times and preferably 1×10 of the volume of liquid milk ^-2 More preferably 1X 10 of the volume of the liquid milk ^-2 More than two times and less than 4 times, and most preferably 1×10 ^-2 More than two times and less than 3 times.

In order to disperse a predetermined gas in liquid milk, the predetermined gas is preferably applied. The pressure for pressurizing the predetermined gas is not particularly limited as long as the predetermined gas can be dispersed in the liquid milk effectively, and examples of the pressure of the predetermined gas include 1.5 atmospheres or more and 10 atmospheres or less, and preferably 2 atmospheres or more and 5 atmospheres or less. Since the liquid milk is sprayed in the following spray drying step, the liquid milk flows along a predetermined flow path, and in the gas dispersing step, the pressurized predetermined gas is caused to flow through the flow path, whereby the gas is dispersed (mixed) in the liquid milk. By doing so, the predetermined gas can be easily and reliably dispersed in the liquid milk.

Thus, the density of the liquid milk is reduced by the gas dispersion step, and the apparent volume (volume) is increased. The density of the liquid milk may be obtained as a value obtained by dividing the weight of the liquid milk by the entire volume of the liquid milk in the liquid state and the bubble state. The measurement can be performed by the bulk density measurement method according to JIS (pigment: according to JISK 5101) and by using a density measuring device.

Therefore, the liquid milk in which the predetermined gas is dispersed flows through the above-described flow path. Here, it is preferable that the volume flow rate of the liquid milk in the flow path is controlled to be constant.

In this embodiment, carbon dioxide (carbonic acid gas) may be used as a predetermined gas. In this flow path, the ratio of the volume flow rate of carbon dioxide to the volume flow rate of liquid milk (hereinafter, this percentage is also referred to as "CO" ₂ Mixing ratio [%]") is, for example, 1% or more and 700% or less, preferably 2% or more and 300% or less, more preferably 3% or more and 100% or less, and most preferably 5% or more and 45% or less. In this way, by controlling the volumetric flow rate of carbon dioxide to be constant with respect to the volumetric flow rate of liquid milk, uniformity of milk powder produced therefrom can be improved. However, CO ₂ When the mixing ratio is too large, the ratio of the liquid milk flowing in the flow path becomes low, and the manufacturing efficiency of the milk powder deteriorates. Thus, CO ₂ The upper limit of the mixing ratio is preferably 700%. The pressure at which carbon dioxide is applied is not particularly limited as long as it is within a range that carbon dioxide can be effectively dispersed in liquid milk, and examples of the pressure of carbon dioxide include 1.5 atmospheres or more and 10 atmospheres or less, and preferably 2 atmospheres or more and 5 atmospheres or less. By continuously (on-line) mixing carbon dioxide and liquid milk in a closed system, it is possible to reliably prevent the contamination of bacteria and the like, and to improve the hygienic state of the milk powder (or maintain high cleanliness).

In the present embodiment, the predetermined gas used in the gas dispersing step is carbon dioxide (carbonic acid gas). Can be used instead of, or in addition to, carbon dioxide, selected from the group consisting of air, nitrogen (N) ₂ ) And oxygen (O) ₂ ) A rare gas (for example, argon (Ar) or helium (He)) may be used as 1 or 2 or more gases in the group consisting of the above gases. In this way, since various gases can be used as options, the gas dispersing process can be easily performed by using the readily available gas. In the gas dispersion step, when an inert gas such as nitrogen or a rare gas is used, there is no concern that the inert gas reacts with the nutrient components of the liquid milk Therefore, the liquid milk is less likely to be deteriorated than the use of air or oxygen, and is preferable. In this case, the ratio of the volume flow rate of the gas to the volume flow rate of the liquid milk is, for example, 1% or more and 700% or less, preferably 1% or more and 500% or less, more preferably 1% or more and 400% or less, and most preferably 1% or more and 300% or less. For example, BELL et al (R.W.BELL, F.P.HANRAHAN, B.H.WEBB: "FOAM SPRAY DRYING METHODS OF MAKING READILY DISPERSIBLE NONFAT DRY MILK", J.Dairy Sci,46 (12) 1963.Pp 1352-1356) states that: about 18.7 volumes of air were blown into the fat-free milk in order to obtain skim milk powder. In the present invention, by dispersing the gas in the above-described range, a milk powder having characteristics preferable for producing solid milk can be obtained. However, in order to ensure that the density of the liquid milk is reduced by dispersing the predetermined gas in the liquid milk in the gas dispersing step, it is preferable to use a gas that is easily dispersed in the liquid milk or a gas that is easily dissolved in the liquid milk as the predetermined gas. Therefore, it is preferable to use a gas having high solubility in water (water solubility), preferably at 20℃under 1 atmosphere and 1cm ³ Solubility in water of 0.1cm ³ The above gases. The carbon dioxide is not limited to the gas, and may be dry ice, or may be a mixture of dry ice and gas. That is, in the gas dispersing step, a solid may be used as long as a predetermined gas can be dispersed in the liquid milk. In the gas dispersion step, dry ice is used, whereby carbon dioxide can be rapidly dispersed in the liquid milk in a cooled state, and as a result, milk powder having characteristics preferable for producing solid milk can be obtained.

The spray drying process is a process for evaporating moisture in liquid milk to obtain milk powder (food powder). The powdered milk obtained in the spray drying step is powdered milk obtained by a gas dispersion step and a spray drying step. The milk powder has a larger volume than milk powder obtained without the gas dispersion step. The volume of the former is preferably 1.01 to 10 times, but may be 1.02 to 10 times, or 1.03 to 9 times.

In the spray drying step, the liquid milk is directly spray dried in a state in which the gas specified in the gas dispersing step is dispersed in the liquid milk and the density of the liquid milk is reduced. Specifically, it is preferable to perform spray drying in a state where the volume of the liquid milk after the dispersion of the gas is 1.05 times or more and 3 times or less, preferably 1.1 times or more and 2 times or less, as compared with the liquid milk before the dispersion of the gas. That is, in the spray drying step, spray drying is performed after the gas dispersing step is completed. However, immediately after the gas dispersion step, the liquid milk is not in a uniform state. Therefore, the spray drying step is performed at 0.1 to 5 seconds, preferably at 0.5 to 3 seconds after the gas dispersing step is completed. That is, the gas dispersing step and the spray drying step may be continuous. By doing so, the liquid milk can be continuously fed into the gas dispersing device to disperse the gas, and the liquid milk in which the gas is dispersed can be continuously supplied to the spray drying device to continue the spray drying.

For evaporating the water, a spray dryer (spray dryer) may be used. Here, the spray dryer has: the liquid milk supply device includes a flow path for flowing liquid milk, a pressurizing pump for pressurizing the liquid milk so as to flow the liquid milk along the flow path, a drying chamber wider than the flow path connected to an opening of the flow path, and a spraying device (a nozzle, an atomizer, or the like) provided in the opening of the flow path. In the spray dryer, the liquid milk is transported along the flow path to the drying chamber by the pressurizing pump so as to have the above-described volume flow rate, and the concentrated milk is diffused into the drying chamber by the spraying device in the vicinity of the opening of the flow path, and the liquid milk in a droplet (atomized) state is dried by a high temperature (for example, hot air) in the drying chamber. That is, the liquid milk is dried in the drying chamber, whereby the moisture can be removed, and as a result, the concentrated milk becomes a powdery solid, that is, a powdered milk. The drying conditions in the drying chamber are appropriately set, so that the amount of moisture in the milk powder is adjusted to prevent the milk powder from accumulating. In addition, by using a spraying device, the surface area per unit volume of the liquid droplets is increased, and the particle size of the powdered milk is adjusted while improving the drying efficiency.

By performing the above-described steps, milk powder suitable for producing solid milk can be produced.

The powdered milk obtained as described above is compression molded to form a powdered milk compression molded product. Next, the obtained powdered milk compression molded product is subjected to a hardening treatment including, for example, a humidifying treatment and a drying treatment. The solid milk 10S can be produced by the above.

In the process of compression molding powdered milk, a compression device is used. The compression device is, for example, a compression molding machine such as a tablet press or a compression test device. The tablet press is provided with a die into which powdered milk is put, and a punch capable of striking the die. Hereinafter, a compression molding process by a tablet press will be described.

Fig. 4 is an explanatory diagram for explaining positions of a slide plate, an upper punch, and a lower punch of the tablet press. In the molding region of the tablet press, a lower punch 31 is disposed below the socket 30A of the slide plate 30 so as to be movable up and down by an actuator. Further, an upper punch 32 is disposed above the socket 30A of the slide plate 30 so as to be movable up and down by an actuator. Fig. 4 shows: the lower punch 31 and the upper punch 32 are inserted into the socket 30A of the slide plate 30, and the lower punch 31 and the upper punch 32 are positioned closest to each other. In this position, the distance between the lower punch 31 and the upper punch 32 is the final punch spacing L. The inner wall surface of the socket 30A of the slide plate 30, the upper end surface of the lower punch 31, and the lower end surface of the upper punch 32 become compression-molded dies. For example, by supplying powdered milk to a recess formed by the inner wall surface of the socket 30A of the slide plate 30 and the upper surface of the lower punch 31, and striking the upper punch 32 from above the socket 30A, a compression pressure is applied to the powdered milk, and the powdered milk is compression molded in a space SP surrounded by the inner wall surface of the socket 30A of the slide plate 30, the upper end surface of the lower punch 31, and the lower end surface of the upper punch 32, whereby a powdered milk compression molded product can be obtained.

The actuators for driving the lower punch 31 and the upper punch 32 up and down are constituted by, for example, servo motors. In this embodiment, the constitution is as follows: by changing the speed of the servo motor as an actuator, as described in detail below, the compression speed at the time of compression molding, that is, the moving speeds of the lower punch 31 and the upper punch 32 can be changed. The actuator is not limited to a servo motor, and the method of changing the moving speeds of the lower punch 31 and the upper punch 32 is not limited thereto. For example, an oil pressure cylinder or the like may also be used. In the compression molding, the lower punch 31 and the upper punch 32 may be moved in directions approaching each other, or may be fixed so that only the other is moved.

A process of compression molding by changing the compression speed at the time of compression molding, that is, the moving speeds of the lower punch 31 and the upper punch 32 will be described. At the time of the compression molding, the compression speed at which the upper end face of the lower punch 31 and the lower end face of the upper punch 32 approach each other is changed (switched). Namely, first at the 1 st compression speed V ₁ The 1 st compression is carried out, and the 1 st compression is followed by the 2 nd compression speed V ₂ And carrying out the 2 nd compression. In the present embodiment, the compression speed V2 is set ₂ Compression speed V of 1 st ₁ Slow.

In this example, as shown in fig. 4, the compression distance between the 1 st compression and the 2 nd compression is based on the state at the end of the 2 nd compression, that is, the end of the entire compression process. The compression by the lower punch 31 and the upper punch 32 is performed until the punch interval between the upper end surface of the lower punch 31 and the lower end surface of the upper punch 32 becomes the final punch interval L. The final punch interval L is the final thickness of the milk powder compression molded product in a state compressed in the whole compression process. The final punch interval L is determined in consideration of expansion of the powdered milk compression molded product at the time of decompression, and has a value smaller than or equal to the target thickness of the powdered milk compression molded product.

In the tablet press according to the embodiment, when switching between the 1 st compression and the 2 nd compression is performed, control is performed as follows: the two surfaces of the lower punch 31 and the upper punch 32 are brought into close contact with the compressed object, and the pressure applied to the compressed object is not released. On the other hand, in a conventionally known tablet press (for example, a tablet press described in japanese patent application laid-open No. 2008-290145), after pre-compression is applied for the purpose of discharging air or the like contained in a compressed material, the following control is performed: the pressure is temporarily released and then the main pressure is applied to shape the compressed article. Unlike the conventional tablet press, the tablet press of the embodiment can provide a sufficient hardness to the compressed product by bringing both surfaces of the lower punch 31 and the upper punch 32 into close contact with the compressed product without releasing the pressure between the 1 st compression and the 2 nd compression.

Fig. 5 shows the positions of the lower punch 31 and the upper punch 32 at the start of the 1 st compression. Fig. 6 shows the positions of the lower punch 31 and the upper punch 32 after the end of the 1 st compression and at the start of the 2 nd compression. From the punch spacing (L+L) shown in FIG. 5 ₁ +L ₂ ) Is compressed to a state of the punch interval (l+l) shown in fig. 6 ₂ ) The compression of the state of (2) is the 1 st compression. Further, from the punch interval (l+l) shown in fig. 6 ₂ ) The compression of the state of (2) to the state of the final punch interval L shown in fig. 4 is the 2 nd compression.

1 st compression distance L of 1 st compression ₁ Is the distance that the punches are spaced apart by a reduced distance in compression 1. 2 nd compression distance L of 2 nd compression ₂ Is the distance that the punches are spaced apart by a reduced distance in compression 2. Since the 2 nd compression is continued after the 1 st compression without decompression, the 2 nd compression distance L ₂ Is from the punch spacing (L+L) compressed by compression 1 ₂ ) Compression distance to the final ram spacing (L).

The variation speed of the punch interval in the 1 st compression is the 1 st compression speed V ₁ The variation speed of the punch interval in the 2 nd compression is the 2 nd compression speed V ₂ . When the variation speed of the punch interval between the 1 st compression and the 2 nd compression varies, the average speed is defined as the 1 st compression speed V ₁ Compression speed V2 ₂ 。

By following compression at a compression rate V of 1 st ₁ Slow compression speed V2 ₂ The compression of the No. 2 is carried out so as to follow the compression speed V of the No. 1 ₁ The same compression speed and the same compression distance (L ₁ +L ₂ ) The hardness of the milk powder compression molded product can be improved and the cracking resistance can be ensured as compared with the case of compression. Further, the 2 nd compression after the 1 st compression can be performed to shorten the 2 nd compression distance L ₂ Therefore, the compression speed V of 2 nd can be maintained ₂ The same degree of manufactureIs manufactured with a high strength and further improved productivity.

In the present embodiment, in order to effectively increase the hardness of the powdered milk compression molded product, the 2 nd compression method, that is, the 2 nd compression speed V, is determined so as to satisfy the 2 nd compression condition ₂ And the 2 nd compression distance L ₂ The 2 nd compression condition is: the state of the compressed powdered milk compression molded product is compressed from the state of being compressed by the 1 st compression to the state of decreasing the rate of hardness change of the powdered milk compression molded product with respect to the compression distance.

As described above, the compression speed V is based on the 1 st by combining ₁ 1 st compression and based on a specific 1 st compression speed V ₁ Slow compression speed V2 ₂ The compression molding step is performed by compression of the 2 nd stage, whereby the hardness of the milk powder compression molded product can be effectively and greatly improved while suppressing an increase in compression time.

In the above, the compression molding step is described as being performed by combining the 1 st compression and the 2 nd compression, but only the 1 st compression speed V may be used ₁ All compression molding steps are performed. In addition, the compression speed V may be only 2 ₂ Is carried out.

The inventors of the present invention have found that the compression speed V is equal to the 1 st compression speed ₁ 1 st compression distance L ₁ Compression speed V2 ₂ Distance of compression L2 ₂ The following specificities were found from the results of studies on the respective milk powder compression molded products obtained by various combinations of the above: compression speed V of 2 nd ₂ Is set to be higher than the 1 st compression speed V ₁ Hours, relative to the 2 nd compression distance L ₂ The rate of change (rate of increase) of the hardness of the milk powder compression molded product of the change (hereinafter referred to as hardness specificity) decreases. In addition, the inventors have found that: 2 nd compression distance L corresponding to the hardness specificity ₂ According to compression speed V1 ₁ And is also subjected to compression speed V2 ₂ Is a function of (a) and (b).

Regarding the presence of hardness specificity, the reason is presumed to be: changing from a compressed state in which rearrangement of milk powder particles inside the milk powder compression molded article is dominant to a state in which plastic deformation inside the milk powder compression molded article is dominantA compressed state. In addition, the 1 st compression speed V ₁ The larger the powder, the larger the energy required for plastic deformation of the inside of the milk powder compression molded article, so that it can be presumed that the compression speed V is based on the 1 st ₁ 2 nd compression distance L corresponding to hardness specificity ₂ Change and the 2 nd compression distance L ₂ Is subjected to compression speed V of 2 nd ₂ Is a function of (a) and (b).

Based on the findings described above, by performing the 2 nd compression so as to satisfy the 2 nd compression condition, the hardness of the milk powder compression molded product is effectively improved greatly while suppressing an increase in the compression time.

In addition, the 1 st compression speed V is also preferably ₁ Relative to compression speed V2 ₂ Compression speed ratio of ratio (=v) ₁ /V ₂ ) Set to 5 or more. By setting the compression ratio to 5 or more, the hardness of the milk powder compression molded product can be greatly increased. The compression speed ratio may be 5 or more, for example, 10 or more, 20 or more, 25 or more, 50 or more, 100 or more, 250 or more, or 500 or more.

Preferably: 1 st compression speed V ₁ The 1 st compression distance L is set to be within a range of 1.0mm/S to 100.0mm/S ₁ The compression speed V2 is set in a range of 5.0mm to 10.0mm ₂ The compression distance L is set to be within the range of 0.25mm/S to 50.0mm/S ₂ The diameter is set to be in the range of 0.2mm to 1.6 mm.

The above-described constitution of the tablet press is an example, and is not limited as long as the tablet press can be compressed by the 1 st compression and the 2 nd compression so as to change the compression speed. In this example, the compression is performed until the final thickness is reached in the 2 nd compression, but after the 2 nd compression, the compression may be further performed at a speed changed from the 2 nd compression speed. At this time, the powdered milk compression molded product was compressed to a final thickness by compression after compression of the 2 nd compression.

The constitution of the tablet press other than the above is, for example, the same as that described in patent document 3. For example, the slide plate socket 30A subjected to compression molding is moved to the take-out area. In the extraction region of the tablet press, the lower punch 31 and the upper punch 32 are extracted from the socket 30A of the slide 30, and the powdered milk compression molded product is extruded through the extrusion section. The extruded milk powder compression molded product is recovered in a recovery tray. In the tablet press described above, the milk powder supply unit to the mortar 30A of the slide plate 30 is realized by a device including a funnel for supplying milk powder from the bottom opening to the mortar 30A, for example.

In the step of compression molding the powdered milk, the temperature of the environment is not particularly limited, and may be, for example, room temperature. Specifically, the temperature of the environment is, for example, 5 to 35 ℃. The humidity of the environment is, for example, 0% RH to 60% RH. The compression pressure is, for example, 1MPa to 30MPa, preferably 1MPa to 20MPa. In particular, when solidifying milk powder, it is preferable that: the compression pressure is controlled so as to be adjusted to a range of 1MPa to 30MPa, and the hardness of the milk powder compression molded product is controlled to be in a range of 4N or more and less than 20N. Thus, the solid milk 10S having high practicality and convenience (ease of handling) can be produced. The powdered milk compression molded product has a hardness (for example, 4N or more) such that it is not deformed at least in the subsequent humidification step and drying step. For example, in consideration of the range of the breaking area, the preferable range of the breaking stress of the milk powder compression molded product is 0.014N/mm ² Above and below 0.067N/mm ² 。

The humidification treatment is a step of humidifying the powdered milk compression molded product obtained in the step of compression molding. When the powdered milk compression molded product is humidified, the surface of the powdered milk compression molded product becomes sticky (sticky). As a result, a part of the powder particles near the surface of the powdered milk compression molded product becomes liquid or gel, and becomes crosslinked with each other. In addition, when the dry is performed in this state, the strength near the surface of the powdered milk compression molded product can be made higher than the strength inside. By adjusting the degree of crosslinking (degree of expansion) by adjusting the time (humidification time) in the high humidity environment, the hardness (for example, 4N or more and less than 20N) of the powdered milk compression molded product (unhardened solid milk 10S) before the humidification step can be increased to the target hardness (for example, 40N) required for the solid milk 10S. However, the range (width) of hardness that can be improved by adjusting the humidification time is limited. That is, since the compressed and molded product of powdered milk is humidified, the shape of the solid milk 10S cannot be maintained if the hardness of the compressed and molded product of powdered milk is insufficient when the compressed and molded product of powdered milk is transported on a belt conveyor or the like. In addition, when the hardness of the milk powder compression molded product is too high during compression molding, only solid milk 10S having a small porosity and lacking in solubility can be obtained. Therefore, in order to sufficiently increase the hardness of the milk powder compression molded product (unhardened solid milk 10S) before the humidification step and sufficiently maintain the solubility of the solid milk 10S, it is preferable to perform compression molding.

In the humidification treatment, a method of humidifying the powdered milk compression molded product is not particularly limited, and there are, for example, the following methods: a method of placing the powdered milk compression molded product in a high humidity environment, a method of directly spraying water or the like onto the powdered milk compression molded product, a method of blowing steam onto the powdered milk compression molded product, and the like. For humidifying the powdered milk compression molded product, a humidifying device is used, and examples of such humidifying devices include a high humidity chamber, mist, steam, and the like.

When the powdered milk compression molded product is placed in a high humidity environment, the humidity of the environment is, for example, in the range of 60% RH to 100% RH relative humidity. The temperature in the high humidity environment is, for example, 30 to 100 ℃. The treatment time for the humidification treatment is arbitrary and is, for example, 5 seconds to 1 hour. The temperature of the compressed milk powder molded product may be set to be higher than 100 ℃ when the compressed milk powder molded product is placed in a high-humidity environment. When placed in an environment of more than 100 ℃, the temperature and humidity are placed in an environment of less than 100% RH. The temperature of the milk powder compression molded product when placed in a high humidity environment is preferably 330 ℃ or lower, more preferably 110 ℃ or higher and 280 ℃ or lower, still more preferably 120 ℃ or higher and 240 ℃ or lower, and still more preferably 130 ℃ or higher and 210 ℃ or lower. The relative humidity of the milk powder compression molded product when placed under a high humidity environment is preferably 0.1% RH or more and 20% RH or less, more preferably 1% RH or more and 15% RH or less, still more preferably 1.5% RH or more and 12% RH or less, and most preferably 2% RH or more and 10% RH or less. The treatment time when the powdered milk compression molded product is placed in a high humidity environment is arbitrary, for example, 0.1 seconds to 30 seconds, preferably 4.4 seconds to 20 seconds, more preferably 4.4 seconds to 12 seconds, still more preferably 5 seconds to 10 seconds. The treatment time may be appropriately set so that the hardness of the solid milk obtained after the drying treatment described later falls within a predetermined range. The humidification conditions include temperature/humidity/time, the higher the temperature, the higher the humidity, the longer the time, the higher the humidification effect, the lower the temperature, the lower the humidity, the shorter the time, and the weaker the humidification effect.

The relative humidity may be measured by a commercially available hygrometer. For example, HMT330 can be measured up to 180℃using the hygrometer of Vaisala, and up to 350℃using the dew point meter of Vaisala, DMT 345. Further, by measuring absolute humidity (volume absolute humidity (unit is g/m ³ ) Or absolute humidity by weight (in kg/kg (DA), where DA is dry air), and calculating the ratio (%) of the partial pressure of water vapor to the saturated water vapor pressure at that temperature, the relative humidity can also be converted.

The amount of water added to the powdered milk compression molded product during the humidification processing (hereinafter also referred to as "humidification amount") can be appropriately adjusted. The amount of humidification is preferably 0.5 to 3% by weight based on the mass of the powdered milk compression molded product after the compression molding step. When the amount of humidification is less than 0.5% by weight, sufficient hardness (tablet hardness) cannot be imparted to the solid milk 10S, which is not preferable. Further, the powdered milk compression-molded product is not preferable because it becomes excessively liquid or gel-like and dissolves, and the shape of the compression-molded product is deformed.

The drying process is a process for drying the powdered milk compression molded product humidified by the humidification process. Thus, the surface tackiness (tackiness) of the milk powder compression molded product disappears, and the solid milk 10S becomes easy to handle. That is, the humidification processing and the drying processing correspond to a step of improving the hardness of the compressed milk powder molded product after compression molding and imparting desired characteristics and qualities to the milk powder 10S as solid milk.

In the drying treatment, the method for drying the powdered milk compression molded product is not particularly limited, and a known method capable of drying the powdered milk compression molded product subjected to the humidification treatment may be used. For example, there are the following methods: a method of being placed under a low humidity/high temperature environment, a method of contacting dry air/high temperature dry air, and the like.

When the milk powder compression molded product is placed under a low humidity/high temperature environment, the milk powder compression molded product is placed under an environment of a relative humidity of 0% RH or more and 30% RH or less and a temperature of 20 ℃ or more and 330 ℃ or less. The temperature when placed in a low humidity/high temperature environment is, for example, 330 ℃. The treatment time when the milk powder compression molded product is placed in a low humidity/high temperature environment is arbitrary, for example, 0.1 seconds or more and 2 hours or less.

The humidification treatment and the drying treatment may be performed as another step under conditions where the temperature and the humidity are different from each other as described above, and in this case, the humidification treatment and the drying treatment may be performed continuously. In addition, the humidification processing and the drying processing may be performed at the same temperature and humidity, in which case the humidification processing and the drying processing may be performed simultaneously. For example, the powdered milk compression molded product is placed in a 1 st temperature/humidity environment in which humidification and drying occur simultaneously, and then the powdered milk compression molded product is placed in a 2 nd temperature/humidity environment in which only drying occurs. The period of transition from the 1 st temperature humidity to the 2 nd temperature humidity is: a period of transition from a state in which humidification and drying of the powdered milk compression molded article simultaneously occur to a state in which only drying of the powdered milk compression molded article occurs.

However, when the moisture content in the solid milk 10S is large, the storage stability is poor, and deterioration of flavor and discoloration of appearance are likely to be accelerated. Therefore, it is preferable that: in the drying step, the moisture content of the solid milk 10S is controlled (adjusted) to be within about 1% of the moisture content of the milk powder used as the raw material by controlling the conditions such as the drying temperature and the drying time.

The solid milk 10S thus produced is usually dissolved in warm water and used for drinking. Specifically, the warm water is poured into a container or the like capable of being capped, and then the desired amount of solid milk 10S is poured, or the solid milk 10S is poured, and then the warm water is poured. Then, the solid milk 10S is preferably dissolved rapidly by gently shaking the container, and is drunk in a state of a proper temperature. In addition, it is preferable that 1 to more solid milk 10S (more preferably 1 solid milk 10S) is dissolved in warm water so as to be a liquid milk in an amount required for 1 drinkTo make the volume of the solid milk 10S 1cm, for example ³ ～50cm ³ . The volume of the solid milk 10S can be adjusted by changing the amount of the powdered milk used in the compression molding step.

By performing the hardening treatment including, for example, the humidification treatment and the drying treatment as described above, it is possible to produce solid milk having a breaking stress of 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

(action/Effect of solid milk 10S)

The solid milk 10S of the present embodiment is a solid milk obtained by compression molding and hardening of powdered milk, and the breaking stress of the solid milk 10S is 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

Conventionally, there has been no solid milk having a region with a high crystallization rate increase ratio β/(α+β) and a high adhesion. The solid milk of the present embodiment ensures easy handling strength, and can achieve a concentration of more than 0.015N/mm ² Is a peeling shear stress of (a). The peel shear stress is a value obtained by dividing the adhesion force by the peel area. The above-described solid milk improves the adhesion force, and the adhesion force of the solid milk in the manufacturing process to the contact surface of the manufacturing apparatus such as the belt conveyor increases, so that the solid milk can be suppressed from being blown off even if the solid milk conveying speed is increased, the solid milk can be stably conveyed, and the manufacturing efficiency can be improved.

< embodiment 2 >

Solid milk is an example of solid food. In embodiment 1, the powdered milk compression-molded product obtained by compression-molding powdered milk and the solid milk obtained by curing the powdered milk are described, but the present invention is not limited to these. The present embodiment is applicable to a food powder compression molded product obtained by compression molding a food powder, and a solid food obtained by hardening the food powder compression molded product.

As the above-mentioned food powder, other than milk powder, protein powder such as whey protein, soybean protein and collagen peptide, amino acid powder, MCT oil-containing powder and the like can be used. Lactose or other sugar may also be suitably added to the food powder. The food powder may also contain nutritional components such as fat, protein, minerals and vitamins, and food additives in addition to lactose or other sugar.

The food powder compression molded product can be formed by using food powder and compression molding the food powder into a desired shape. The obtained food powder is hardened by compression molding, whereby a solid food can be formed. The food powder described above can be produced by performing a hardening treatment including the same humidification treatment as in embodiment 1, except that the food powder is used as a raw material.

The hardness of a food powder compression molded product obtained by compression molding a food powder or a solid food obtained by hardening the food powder can be measured by using the durometer described in embodiment 1. The food powder compression molded product preferably has a hardness of 4N or more and less than 20N, and the solid food preferably has a hardness of 20N or more and 130N or less. In addition, the preferred breaking stress of the food powder compression molded product is 0.014N/mm ² Above and below 0.067N/mm ² The preferred breaking stress of the solid food is 0.067N/mm ² Above and 0.961N/mm ² The following is given.

The solid food according to the present embodiment is a solid food in a solid form obtained by hardening a food powder by compression molding, and has a breaking stress of 0.067N/mm ² The above. Here, the peel shear stress for a flat face is greater than 0.015N/mm ² 。

The solid food according to the present embodiment described above ensures easy handling strength, and can achieve a concentration of more than 0.015N/mm ² And stripping the shear stress. The peel shear stress is a value obtained by dividing the adhesion force by the peel area. The solid food improves the adhesion force, and the adhesion force of the solid food in the manufacturing process to the contact surface of the manufacturing device such as the belt conveyor is increased, so that the solid food can be prevented from being blown off even if the conveying speed of the solid food is increased, the solid food can be stably conveyed, and the manufacturing efficiency can be improved.

The solid food of the present embodiment described above preferably contains monohydrate crystals and anhydrate crystals, and the difference in the ratio of the monohydrate crystals to the total weight of the surface of the solid food to the ratio of the monohydrate crystals in the interior of the solid food is an increase α (weight%) in crystallization rate; the difference between the ratio of the anhydrous crystals on the surface of the solid food relative to the total weight and the ratio of the anhydrous crystals in the solid food is β (wt%) which is an increase in crystallization rate, and the ratio β/(α+β) which is an increase in crystallization rate of the sum of α (wt%) and β (wt%) which is an increase in crystallization rate, is taken as Xa, and when Ya (N) is a peel shear stress of the solid food with respect to a flat surface, xa and Ya satisfy the following formula (1A).

0.1326Xa-0.0013＜Ya＜0.1326Xa+0.0087…(1A)

The solid food according to the present embodiment is preferably further provided that the increase ratio β/(α+β) of the crystallization rate is 0.3 or less.

Such solid food can be produced by subjecting a food powder compression molded product obtained by compression molding of a food powder to a hardening treatment including, for example, a humidifying treatment and a drying treatment as described above, and has a strength that is easy to handle and can further improve the adhesion.

The protein powder of the food powder may be milk casein, meat meal, fish meal, egg meal, wheat protein decomposition products, or the like. These protein powders may be used alone or in combination of two or more.

Furthermore, whey protein (whey protein) of the food powder is a generic term for proteins other than casein in milk. Whey proteins can be classified. Whey protein is composed of a plurality of components such as lactoglobulin, lactalbumin, lactoferrin, etc. When the milk raw material such as milk is made acidic, the precipitated protein is casein and the non-precipitated protein is whey protein. Examples of the powdery raw material containing whey protein include WPC (whey protein concentrate, protein content of 75 to 85 mass%), WPI (whey protein isolate, protein content of 85 mass% or more). These may be used alone or in combination of two or more.

The soybean protein (Soy protein) in the food powder may be a protein contained in soybean, or may be extracted from soybean. Alternatively, a soybean product purified from raw soybean may be used. The purification method is not particularly limited, and conventionally known methods can be used. As such soybean proteins, commercially available powders can be used as food and drink materials, medical materials, and nutrition enhancer foods. These may be used alone or in combination of two or more.

Further, the amino acids contained in the amino acid powder of the food powder are not particularly limited, and for example, arginine, lysine, ornithine, phenylalanine, tyrosine, valine, methionine, leucine, isoleucine, tryptophan, histidine, proline, cysteine, glutamic acid, asparagine, aspartic acid, serine, glutamine, citrulline, creatine, methyllysine, acetyllysine, hydroxylysine, hydroxyproline, glycine, alanine, threonine, cystine, and the like can be used. These may be used alone or in combination of two or more.

The amino acid contained in the amino acid powder of the food powder may be natural or synthetic, and a single amino acid or a mixture of a plurality of amino acids may be used. As the amino acid, not only a free amino acid but also salts such as sodium salt, hydrochloride and acetate, and derivatives such as carnitine and ornithine may be used.

In the present specification, "amino acid" includes alpha-amino acid, beta-amino acid and gamma-amino acid. In addition, the amino acid may be either L-form or D-form.

The fat contained in the fat-containing powder of the food powder may be animal fat, vegetable fat, separated oil thereof, hydrogenated oil, or transesterified oil, in addition to the MCT oil. One or two or more of these may be added. Animal fats and oils are, for example, milk fat, lard, tallow, fish oil, and the like. Vegetable oils and fats are, for example, soybean oil, rapeseed oil, corn oil, coconut oil, palm kernel oil, safflower oil, cottonseed oil, linseed oil, MCT oil, and the like.

Further, the sugar of the food powder is, for example, oligosaccharide, monosaccharide, polysaccharide, artificial sweetener, or the like, in addition to the lactose. One or two or more of these may be added. Examples of oligosaccharides are lactose, sucrose, maltose, galacto-oligosaccharides, fructo-oligosaccharides, lacto-ketose and the like. The monosaccharides include, for example, glucose, fructose, galactose, etc. Examples of the polysaccharides include starch, soluble polysaccharides, and dextrins.

Further, as an example of the food additive of the above-mentioned food powder, a sweetener can be exemplified. As the sweetener, any sweetener commonly used for foods and medicines may be used, and any of natural sweeteners and synthetic sweeteners may be used. The sweetener is not particularly limited and includes, for example, glucose, fructose, maltose, sucrose, oligosaccharides, granulated sugar, maple syrup, honey, molasses, trehalose, palatinose, maltitol, xylitol, sorbitol, glycerin, aspartame, alitame, neotame, sucralose, acesulfame potassium, saccharin and the like.

Further, as an example of the food additive of the above-mentioned food powder, a sour agent can be exemplified. The sour agent is not particularly limited and includes, for example, acetic acid, citric acid, anhydrous citric acid, adipic acid, succinic acid, lactic acid, malic acid, phosphoric acid, gluconic acid, tartaric acid, salts thereof, and the like. The sour agent can suppress (mask) bitter taste caused by the difference in the kind of amino acid.

Further, the nutritional ingredients of the food powder may include all ingredients such as fat, protein, minerals, and vitamins.

Examples of fats include animal fats and oils, vegetable fats and oils, their separated oils, hydrogenated oils, and transesterified oils. One or two or more of these may be added. Animal fats and oils are, for example, milk fat, lard, tallow, fish oil, and the like. Vegetable oils and fats are, for example, soybean oil, rapeseed oil, corn oil, coconut oil, palm kernel oil, safflower oil, cottonseed oil, linseed oil, MCT oil, and the like.

Examples of the protein include milk proteins and fractions of milk proteins, animal proteins, vegetable proteins, peptides and amino acids having various chain lengths obtained by degrading these proteins with enzymes, and the like. One or two or more of these may be added. Milk proteins are, for example, casein, whey proteins (alpha-lactalbumin, beta-lactoglobulin, etc.), whey Protein Concentrates (WPC), whey Protein Isolates (WPI), etc. The animal protein is, for example, egg protein (egg powder), meat powder, fish powder, etc. The vegetable proteins are, for example, soybean proteins, wheat proteins, and the like. The peptide is, for example, a collagen peptide. Amino acids are, for example, taurine, cystine, cysteine, arginine, glutamine, and the like. One or two or more of these may be added.

As minerals, iron, sodium, potassium, calcium, magnesium, phosphorus, chlorine, zinc, iron, copper, selenium, and the like are mentioned. One or two or more of these may be added.

As the vitamins, vitamin a, vitamin D, vitamin E, vitamin K, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, niacin, folic acid, pantothenic acid, biotin, and the like are mentioned. One or two or more of these may be added.

Examples of the other food materials include Cocoa powder (Cocoa powder), raw Cocoa powder (Cacao powder), chocolate powder, microbial powder containing useful microorganisms such as lactic acid bacteria and bifidobacteria, milk fermentation component powder obtained by adding a microorganism to milk and fermenting the obtained culture into the milk, cheese powder obtained by pulverizing cheese, functional food powder obtained by pulverizing functional food, and comprehensive nutrition food powder obtained by pulverizing comprehensive nutrition food. One or two or more of these may be added.

The solid food of the present invention may be in the form of daily intake food, health auxiliary food, health functional food, specific health food, nutritional functional food, nutritional enhancer, functional labeling food, etc.

Solid foods having the property of dissolving in water may also be referred to as solid dissolution foods.

When the food powder contains a water-soluble material or a hygroscopic material, there is a possibility that tackiness (tackiness) may occur on the surface of the food powder compression molded product when the food powder compression molded product obtained by compression molding the food powder is humidified. Examples of such food powder include food powder containing sugar, dextrin, natural sugar (trehalose, etc.), polysaccharides, etc. In addition, when the food powder compression molded product is humidified, the food powder may be suitably used as long as it is a food powder that may cause tackiness (tackiness) on the surface of the food powder compression molded product.

(action/Effect of solid food)

The solid food according to the present embodiment is a solid food in a solid form obtained by hardening a food powder by compression molding, and has a breaking stress of 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

Conventionally, there has been no solid food having a region with a high crystallization rate increase ratio β/(α+β) and a high adhesion. The solid food according to the present embodiment ensures easy handling strength, and can achieve a concentration of more than 0.015N/mm ² Is a peeling shear stress of (a). The peel shear stress is a value obtained by dividing the adhesion force by the peel area. The solid food improves the adhesion force, and the adhesion force of the solid food in the manufacturing process to the contact surface of the manufacturing device such as the belt conveyor is increased, so that the solid food can be prevented from being blown off even if the conveying speed of the solid food is increased, the solid food can be stably conveyed, and the manufacturing efficiency can be improved.

< embodiment >

(production of example 1)

A solid milk sample in a rectangular parallelepiped shape was prepared in which the X-axis direction side a was 31mm, the Y-axis direction side b was 24mm, and the Z-axis direction side c was 12.5 mm. The size of the mortar punch of the tablet press having such a size was adjusted, and 5.4g of powdered milk was compression molded to form a powdered milk compression molded product. Compression was performed at a compression speed V of 1 mm/s. The compressed milk powder molded product obtained above was subjected to humidification treatment at 75℃for 95% RH for 90 seconds, with respect to temperature and relative humidity. After the humidification treatment, a drying treatment at a drying temperature of 80℃was performed as the solid milk sample of example 1 subjected to the hardening treatment. For the drying time, the time is adjusted so that the weight-increasing portion upon humidification can be completely dried.

(hardness of sample of example 1)

The hardness of the solid milk sample of example 1 was evaluated using the load cell tablet durometer described above. The hardness of the test piece of example 1 was 128N (breaking stress was 0.427N/mm) ² Left and right), the hardness is sufficiently ensured, and the hardness is easy to handle.

( Measurement of the increase in crystallization rate of alpha lactose crystals and the increase in crystallization rate of beta lactose crystals of the sample of example 1; calculation of the increase ratio β/(α+β) of the crystallization rate of β lactose crystals to the sum of the increase β of the crystallization rate and the increase α of the crystallization rate (α+β) )

For the sample of the solid milk of example 1, an increase α (wt%) in the crystallization rate of α lactose crystals per unit weight in the depth direction from the surface, an increase β (wt%) in the crystallization rate of β lactose crystals, and a total of the increases in the crystallization rate (sum of the increase α in crystallization rate and the increase β in crystallization rate (α+β)) were obtained by XRD (X-ray diffraction) method. The increase in the crystallization rate of the α lactose crystals, the increase in the crystallization rate of the β lactose crystals, and the increase in the total crystallization rate are calculated as the ratio (wt%) of the sum of the α lactose crystals, the β lactose crystals, and the crystals of α lactose and β lactose, respectively, to the total weight, and the calculated value is obtained by subtracting the crystallization rate in the solid milk from the increase in the internal. The increase ratio β/(α+β) of the crystallization rate of the surface of the solid milk sample of example 1 was 0.237. In the measurement by the XRD method, the surface was cut every time the XRD was measured on the measurement surface of each sample, and the crystallization rate of the entire surface was increased. The measurement surface was a cross section of 12.5mm×24 mm.

Summary of the inventionthe increase in crystallization rate was measured by diffraction intensity using a powder X-ray diffraction apparatus (XRD, smartLab, rigaku Corporation) on the surface exposed by cutting the surface of the solid milk by a thickness of 0.1 mm. The measurement methods were general (focusing method), slit conditions were scan axis (2θ/θ), mode (stepwise), range designation (absolute), start (9.0000 deg), end (13.5000 deg), step size (0.0200 deg), speed count time (2.4), IS (1.000 deg), RSI (1.000 deg), RS2 (0.300 mm), attenuator (open), tube voltage (40 kv), tube current (30 mA).

Analysis method Using analysis software "SmartLab StudioII", the integrated intensity calculation was performed after the weighted average (smoothed 7-point) BG removal (sonnneveld-Visser method) treatment (inherent peak of. Alpha. -lactose crystal: 12.5, inherent peak of. Beta. -lactose crystal: 10.5). Summarizing the increase in crystallization rate is the difference between the ratio of crystals relative to the total weight at each depth of the solid milk from the surface and the ratio of crystals inside the solid milk. Here, the crystals were obtained as the weight (wt%) of the α lactose crystals and β lactose crystals per unit weight.

(measurement of adhesion of sample of example 1)

In order to evaluate the adhesion based on the hardening condition, the adhesion test was performed on the solid milk sample of example 1 manufactured as described above. In the adhesion test, the solid milk subjected to the hardening treatment was loaded on the perforated screen in a direction in which the solid milk can be peeled off from the perforated screen by using the load cell type tablet durometer described above, and the force required for peeling was measured as adhesion [ N]. Adhesion indicates the strength of the produced solid milk to adhere to a flat surface. The adhesion of the solid milk sample of example 1 was 14N (peel shear stress was 0.0349N/mm ² )。

Example 2

A solid milk sample was produced as in example 2, in the same manner as in example 1, except that the humidification treatment was performed at a temperature, a relative humidity, and a treatment time of 75 ℃, 75% rh, and 60 seconds. The hardness, the increase ratio β/(α+β) of the crystallization rate of the solid milk surface, and the adhesion were measured in the same manner as in example 1. The hardness of the solid milk sample of example 2 was 68.8N (breaking stress was 0.229N/mm ² ) The crystallization rate of the solid milk surface was increased by 0.108. Beta. (. Alpha. + beta.), the adhesion was 6.9N (peel shear stress was 0.0172N/mm) ² )。

Example 3

A solid milk sample was produced as in example 3, except that the humidification treatment was performed at a temperature, a relative humidity, and a treatment time of 75 ℃, 75% rh, and 80 seconds. The hardness, the increase ratio β/(α+β) of the crystallization rate of the solid milk surface, and the adhesion were measured in the same manner as in example 1. The hardness of the solid milk sample of example 3 was 75.2N (breaking stress 0.251N/mm) ² ) The crystallization rate of the solid milk surface was increased by 0.136. Beta. (. Alpha. + beta.), the adhesion was 8.5N (peel shear stress was 0.0212N/mm) ² )。

Example 4

A solid milk sample was produced as in example 4, in the same manner as in example 1, except that the humidification treatment was performed at a temperature, a relative humidity, and a treatment time of 75 ℃, 75% rh, and 95 seconds. The hardness, the increase ratio β/(α+β) of the crystallization rate of the solid milk surface, and the adhesion were measured in the same manner as in example 1. The hardness of the solid milk sample of example 4 was 90.1N (breaking stress was 0.300N/mm) ² ) The increase ratio of the crystallization rate of the solid milk surface, beta/(alpha+beta), was 0.156, the adhesion was 9.6N (peel shear stress was 0.0239N/mm) ² )。

Comparative example 1

A solid milk sample was produced as in comparative example 1, except that the humidification treatment was performed at a temperature, a relative humidity, and a treatment time of 75 ℃, 50% rh, and 30 seconds. The hardness, the increase ratio β/(α+β) of the crystallization rate of the solid milk surface, and the adhesion were measured in the same manner as in example 1. The hardness of the solid milk sample of comparative example 1 was 32.7N (breaking stress was 0.109N/mm) ² ) The increase ratio of the crystallization rate of the solid milk surface, beta/(alpha+beta), was 0.054, the adhesion was 4.0N (peel shear stress was 0.00995N/mm) ² )。

Comparative example 2

A solid milk sample was produced in the same manner as in example 1, except that the humidification treatment was performed at a temperature, a relative humidity, and a treatment time of 75 ℃, 75% rh, and 30 seconds, to obtain a comparative example 2. Hardness and crystallization Rate of solid milk surface were measured in the same manner as in example 1Increasing the ratio β/(α+β) and the adhesion. The hardness of the solid milk sample of comparative example 2 was 49.8N (breaking stress was 0.166N/mm) ² ) The crystallization rate of the solid milk surface was increased by a ratio of beta/(alpha+beta) of 0.074 and an adhesion of 6.0N (peel shear stress of 0.0149N/mm) ² )。

FIG. 7 is a graph showing the increase ratio β/(α+β) of the crystallization rate of the surface of the solid milk and the breaking stress (N/mm) of the solid milk of the examples and the comparative examples ² ) Is a graph of the relationship of (1). The results of example 1 are shown as darkened delta. The results of comparative examples 1 and 2 are indicated by +. In example 1, the crystallization rate was increased by 0.237% beta/(α+β), and the hardness was 128N (breaking stress was 0.427N/mm) ² ). In comparative examples 1 and 2, the hardness was 32.7N to 49.8N (breaking stress was 0.109N/mm) ² ～0.166N/mm ² ) However, the crystallization rate increase ratio β/(α+β) is 0.054 to 0.074.

FIG. 8 is a graph showing the peel shear stress (N/mm) of the solid milk of examples and comparative examples ² ) And the crystallization rate of the surface of the solid milk. The results of examples 1 to 4 are shown by darkened delta. The results of comparative examples 1 and 2 are indicated by +. In examples 1 to 4, the adhesion was maintained at 6.9N to 14N (peel shear stress was 0.0172N/mm) at an increase ratio β/(α+β) of 0.108 to 0.237 ² ～0.0349N/mm ² ) Is a high value of (2). In comparative examples 1 and 2, the crystallization rate was increased by a ratio of β/(α+β) of 0.054 to 0.074, and the adhesion was 4.0N to 6.0N (peel shear stress was 0.00995N/mm) ² ～0.0149N/mm ² ). The peel shear stress (N/mm) of examples 1 to 4 was measured by the least square method ² ) The graph obtained by approximating the increase ratio β/(α+β) of the crystallization rate of the surface of the solid milk is represented by a straight line (y=0.1326x+0.0037).

The solid milk samples of the examples have a peel shear stress of greater than 0.015N/mm ² It was confirmed that the ratio was higher than that of the comparative example. Thus, the solid milk of the embodiment can improve the adhesion force of the solid milk to the contact surface of the manufacturing apparatus such as the belt conveyor in the manufacturing process. By adjusting the temperature, humidity and treatment time in the hardening treatment, in particular in the humidification treatment, therebyWhen the crystallization rate increase ratio β/(α+β) is Xb and the peeling shear stress of the solid milk with respect to the flat surface is Yb (N), the adhesion of the obtained solid milk can be adjusted within the range of the following formula (1).

0.1326Xb-0.0013＜Yb＜0.1326Xb+0.0087…(1)

Comparative example 3

In compression molding, the 1 st compression distance L is set ₁ Set to 5-15 mm, and the 1 st compression speed V ₁ After the 1 st compression of 1 to 150mm/s, the 2 nd compression distance L is set ₂ Set to 0.1-1.6 mm, and the 2 nd compression speed V ₂ Compression 2 is set to 0.25-15 mm/s. The powdered milk compression molded product obtained in the above was subjected to humidification treatment at a humidification temperature of 80 ℃, 50% rh for 20 seconds, and further to drying treatment at a drying temperature of 80 ℃, to obtain a sample of solid milk of comparative example 3 subjected to hardening treatment. The breaking stress of the solid milk of comparative example 3 was 0.739N/mm ² The peel shear stress was 0.015N/mm ² The following is given. The peel shear stress of the obtained solid milk for a flat face was 0.015N/mm ² The following is given.

Example of embodiment >

The present disclosure may have the following configuration. With the following configuration, the adhesion can be improved and the strength can be easily handled.

(1) A solid food which is a solid food obtained by compression molding of a food powder and has a breaking stress of 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

(2) The solid food according to the above (1), wherein the solid food comprises a monohydrate crystal and an anhydrous crystal, and the difference between the ratio of the monohydrate crystal at the surface of the above solid food relative to the total weight and the ratio of the monohydrate crystal at the inside of the above solid food is an increase α (wt%) in crystallization rate; the difference between the ratio of the anhydrous crystals on the surface of the solid food relative to the total weight and the ratio of the anhydrous crystals inside the solid food is β (wt%) which is an increase in crystallization rate, and the ratio β/(α+β) which is an increase in crystallization rate of the sum (α+β) of the β (wt%) and the α (wt%) which is an increase in crystallization rate, is taken as Xa, and when Ya (N) is a peel shear stress of the solid food with respect to a flat surface, xa and Ya satisfy the following formula (1A).

0.1326Xa-0.0013＜Ya＜0.1326Xa+0.0087…(1A)

(3) The solid food according to the above (2), wherein the crystallization rate is increased by 0.3 or less in the ratio β/(α+β).

(4) A solid milk obtained by compression molding of milk powder, wherein the breaking stress of the solid milk is 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

(5) The solid milk according to the above (4), wherein the above solid milk contains an alpha lactose crystal and a beta lactose crystal, and the difference in the ratio of the above alpha lactose crystal to the total weight of the surface of the above solid milk and the ratio of the above alpha lactose crystal inside the above solid milk is an increase in crystallization rate of alpha (wt%); the difference between the ratio of the β lactose crystals on the surface of the solid milk relative to the total weight and the ratio of the β lactose crystals in the solid milk is the increase β (wt%) in the crystallization rate, the increase ratio β/(α+β) in the crystallization rate is the increase ratio β/(α+β) in the crystallization rate, which is the sum of the increase β (wt%) in the crystallization rate and the increase β (wt%) in the crystallization rate, and when Yb (N) is the peel shear stress of the solid milk to a flat surface, xb and Yb satisfy the following formula (1):

0.1326Xb-0.0013＜Yb＜0.1326Xb+0.0087…(1)

(6) The solid milk according to the above (5), wherein the crystallization rate is increased by 0.3 or less in the ratio β/(α+β).

(7) A solid food is obtained by compression molding a food powder, wherein the food powder is compression molded in the following mannerThe obtained food powder compression molded product is formed by hardening treatment: the breaking stress of the solid food is 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

(8) A solid milk obtained by compression molding a powdered milk, which is obtained by compression molding a powdered milk, and hardening the obtained powdered milk compression molded product in the following manner: the breaking stress of the solid milk is 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

(9) A solid dissolved food which is obtained by compression molding of a food powder and has a breaking stress of 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² 。

(10) A solid food which is a solid food obtained by compression molding of a food powder and has a breaking stress of 0.067N/mm ² The peel shear stress for the flat surface is greater than 0.015N/mm ² The solid food may be made sticky by a hardening treatment.

Description of the reference numerals

10. Main body

10A 1 st side

10B 2 nd side

10C side

10S solid milk

Claims (6)

1. A solid food obtained by compression molding of food powder,

the breaking stress of the solid food is 0.067N/mm ² The above-mentioned steps are carried out,

peel shear stress for flat faces is greater than 0.015N/mm ² 。

2. The solid food according to claim 1, wherein the solid food comprises a monohydrate crystal and an anhydrate crystal,

the difference in the ratio of the monohydrate crystals of the surface of the solid food relative to the total weight and the ratio of the monohydrate crystals of the interior of the solid food is an increase in crystallization rate, α (weight%); the difference between the ratio of the anhydrous crystals on the surface of the solid food relative to the total weight and the ratio of the anhydrous crystals inside the solid food is an increase β (wt%) in crystallization rate, the increase ratio β/(α+β) in crystallization rate is defined as Xa, and when the peel shear stress of the solid food to a flat surface is defined as Ya (N), xa and Ya satisfy the following formula (1A):

0.1326Xa-0.0013＜Ya＜0.1326Xa+0.0087…(1A)。

3. The solid food according to claim 2, wherein the crystallization rate increase ratio β/(α+β) is 0.3 or less.

4. A solid milk obtained by compression molding of powdered milk,

the breaking stress of the solid milk is 0.067N/mm ² The above-mentioned steps are carried out,

peel shear stress for flat faces is greater than 0.015N/mm ² 。

5. The solid milk of claim 4, wherein the solid milk comprises alpha lactose crystals and beta lactose crystals,

the difference in the ratio of the alpha lactose crystals on the surface of the solid milk relative to the total weight and the ratio of the alpha lactose crystals inside the solid milk is an increase in crystallization rate, alpha (wt%); the difference in the ratio of the β lactose crystals on the surface of the solid milk relative to the total weight and the ratio of the β lactose crystals inside the solid milk is an increase in crystallization rate β (wt%); assuming that an increase ratio β/(α+β) of the crystallization rate to a sum (α+β) of the increase β (wt%) of the crystallization rate and the increase α (wt%) of the crystallization rate is Xb, and assuming that the peeling shear stress of the solid milk with respect to a flat surface is Yb (N), xb and Yb satisfy the following formula (1):

0.1326Xb-0.0013＜Yb＜0.1326Xb+0.0087…(1)。

6. Solid milk according to claim 5, wherein the crystallization rate increase ratio β/(α+β) is 0.3 or less.

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