CN116669566A - pet food - Google Patents

Abstract

A pet food having a moisture content of 15% or less, wherein when immersed in water for 5 seconds, 30% or more by mass of water is absorbed relative to 100% by mass of the pet food.

Description

pet food

technical field

The present invention relates to pet food.

This application claims priority based on Japanese Patent Application No. 2020-219694 filed in Japan on December 28, 2020 and Japanese Patent Application No. 2021-213428 filed in Japan on December 27, 2021, the contents of which are incorporated herein.

Background technique

If the pet food is divided into the supply purpose according to the opportunity, it can be divided into staple food and occasional food. The pet food that is the staple food is called "comprehensive nutritional food", and the required nutrients can be taken in as long as the pet food and water are given.

On the other hand, "intermediate food" is a pet food intended to be given in limited quantities as a pet's training, as a reward for exercising, or the like.

According to the classification of the purpose of pet food, it is divided into "comprehensive nutritional food", "intermediate food", "therapy food", and "food for other purposes" that does not correspond to any of the above.

As a classification based on the water content of pet food, it is roughly divided into dry food with a water content of about 10% (12% or less), soft food with a water content of about 25% to 35%, and soft food with a water content of about 25% to 35%. About 25% to 35%, semi-moist food without foaming treatment, and wet food with a moisture content of about 75%. Demand for pet foods with relatively low water content has been increasing in recent years from the viewpoint of ease of handling and good storage properties.

Dry pet food is generally firmer, certainly harder than other types of pet food, and almost all food for human consumption. Dogs and cats were originally carnivorous, and their teeth were mainly developed to grab prey, or to cut meat, and were not suitable for breaking hard substances with molars. Conventional hard dry pet foods cannot be said to be easy-to-eat foods for dogs and cats. Easier-to-crunch granules become easier-to-eat granules, and easy-to-eat is associated with high palatability.

Patent Document 1 discloses a pet food that reduces the hardness of the pet food by immersing dry pet food in water for 10 minutes, thereby improving the pet's appetite (palatability) for the pet food.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2014-187920

Contents of the invention

The problem to be solved by the invention

The pet food described in Patent Document 1 reduces the hardness of the pet food and improves the palatability by immersing the pet food in water for 10 minutes when feeding the pet. However, it can be said that the immersion time of 10 minutes is long from the viewpoint of handling by the feeder of the pet food. In addition, Patent Document 1 discloses that hardness and water absorption of pet food are in an antinomy relationship, and that when the value of hardness increases (hardens), the value of water absorption tends to decrease (no water absorption).

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pet food that has an excellent water absorption rate even under short-time immersion and further improves palatability.

solutions to problems

In order to achieve the above objects, the present invention has the following aspects.

[1] A pet food having a water content of 15% or less and absorbing 30% by mass or more of water relative to 100% by mass of the pet food when immersed in water for 5 seconds.

[2] The pet food according to the above [1], wherein the pet food particles immersed in the water for 5 seconds have a hardness of 50.0N or less.

[3] The pet food according to the above [1] or [2], which absorbs 50% by mass or more of the water relative to 100% by mass of the pet food when immersed in the water for 60 seconds .

[4] The pet food according to any one of the above [1] to [3], wherein when immersed in the water for 5 seconds, the volume of %, the dough expands more than 5% by volume.

[5] The pet food according to any one of [1] to [4] above, wherein, when immersed in the water for 60 seconds, the volume of %, the dough expands more than 5% by volume.

[6] The pet food according to any one of [1] to [5] above, wherein when immersed in the water for 5 seconds, the volume of the pores relative to the pet food before immersion in the water is The ratio is 100%, and the open volume ratio is 85% or less.

[7] The pet food according to any one of the above [1] to [6], wherein when immersed in the water for 60 seconds, the volume of pores relative to the pet food before immersion in the water is The ratio is 100%, and the open volume ratio is 80% or less.

[8] The pet food according to any one of [1] to [7] above, wherein when immersed in the water for 5 seconds, the center of the particle of the pet food before being immersed in the water is The dough area in the section of the part is 100 area%, and the dough area increases by 45 area% or more.

[9] The pet food according to any one of [1] to [8] above, wherein when immersed in the water for 5 seconds, the center of the particle of the pet food before being immersed in the water is The opening area ratio in the cross section of some parts is 100%, and the opening area ratio is 80% or less.

[10] The pet food according to any one of [1] to [9] above, wherein when immersed in the water for 5 seconds, the particle density relative to the pet food before immersion in the water is 100 %, the particle density increases by more than 10%.

[11] The pet food according to any one of [1] to [10] above, wherein when immersed in the water for 60 seconds, the particle density of the pet food before immersion in the water is 100 %, the particle density increases by more than 15%.

[12] A pet food having a moisture content of 15% or less and absorbing 30% by mass or more of the pet food relative to 100% by mass of the pet food when immersed in a liquid with a viscosity of 1.5 dPa·s for 5 seconds. the liquid.

[13] The pet food according to the above [12], wherein the pet food particles immersed in the liquid for 5 seconds have a hardness of 50.0N or less.

The effect of the invention

According to the present invention, it is possible to provide a pet food that has an excellent water absorption rate even under short-time immersion and has improved palatability.

Description of drawings

Fig. 1 is a schematic diagram showing a pet food according to an embodiment of the present invention.

Fig. 2 is a schematic diagram illustrating a projection surface obtained by projecting the pet food according to the embodiment of the present invention in various directions.

Fig. 3 is a schematic diagram showing a pet food according to another embodiment of the present invention.

Fig. 4 is a schematic diagram illustrating a projection surface obtained by projecting pet food according to another embodiment of the present invention in various directions.

FIG. 5 is a schematic diagram for explaining the method of manufacturing the pet food according to this embodiment.

Fig. 6 is a CT image obtained by measuring the cross section of the central portion of the particles perpendicular to the plane from the first direction in Fig. 1 of the pet food of the example before being immersed in water.

Fig. 7 is a CT image obtained by measuring the cross-section of the central part of the particle perpendicular to the plane from the first direction in Fig. 1 of the pet food of the example after being immersed in water for 5 seconds.

Fig. 8 is a CT image obtained by measuring a cross-section of a central part of a particle perpendicular to a plane from one direction of commercially available pet food for dogs before immersion in water.

Fig. 9 is a CT image obtained by measuring a cross-section of a central portion of a particle perpendicular to a plane from one direction of commercially available pet food for dogs after immersion in water for 5 seconds.

Fig. 10 is a CT image obtained by measuring a cross section of a central portion of a particle perpendicular to a plane from one direction of commercially available pet food for cats before immersion in water.

Fig. 11 is a CT image obtained by measuring the cross section of the central part of the grain perpendicular to the plane from one direction of commercially available pet food for cats after being immersed in water for 5 seconds.

Detailed ways

In this specification, "pet" refers to an animal kept by a human being. In a narrower sense, a pet is an animal for the owner to play with. In addition, "pet food" means feed for pets. The pet food of the present invention can be sold as "feed for animals" or "bait for animals".

In this specification, "palatability" refers to an index of whether pets like to eat, and is derived from texture, taste, smell, and the like.

In this specification, the value of moisture content means the value obtained by the "drying loss method".

The drying loss method is a method in which a sample is heated and dried by infrared irradiation, and the amount of water in the sample is obtained from the mass change caused by the evaporation of the contained water. The water content can be measured using a known device. For example, the moisture content can be measured with Infrared Moisture Analyzer FD-720 (manufactured by Kett Scientific Research Institute Co., Ltd.).

In this specification, moisture content and water absorption are different definitions. Moisture content is the amount of moisture the pet food itself has. Water absorption is the amount of water absorbed by the pet food when the pet food is submerged in water.

In this specification, the particle size of the pet food refers to the diameter when the shape of the particle of the pet food is spherical, and refers to the diameter when the shape of the particle of the pet food is other than spherical (cylindrical, polygonal column, plate, etc.). shape, etc.) refers to the longest diameter.

(pet food)

The pet food of this embodiment (hereinafter, also referred to as "the pet food of the first embodiment") is a pet food with a moisture content of 15% or less, and when immersed in water for 5 seconds, relative to 100% by mass of the pet food, , absorb more than 30% by mass of water.

It should be noted that the pet food of the present embodiment may consist only of the pet food of the above-mentioned first embodiment, or may be a mixture of the pet food of the above-mentioned first embodiment and other pet foods. It does not specifically limit as another pet food, Dry pet food other than the pet food of the said 1st Embodiment, a raw material, a flake, etc. are mentioned. In the mixture of the pet food of the first embodiment and other pet food, the pet food of the first embodiment may be contained in an amount of 1% or more based on the total amount of the mixture.

《Moisture content》

The pet food of this embodiment is a pet food with a moisture content of 15% or less.

When the water content of the pet food of this embodiment is 15% or less, the storage period of the pet food becomes relatively long, and the odor of the pet food can be suppressed, so it is easy for the breeder to handle the pet food.

The moisture content of the pet food of this embodiment is preferably 12% or less, more preferably 10% or less. The lower limit of the water content of the pet food is not particularly limited, but is typically 3% or more, preferably 4% or more, more preferably 5% or more.

The water activity of the pet food according to this embodiment is preferably less than 0.65.

The spoilage of pet food is mainly caused by the decomposition of protein due to bacteria and mold. Depending on the kind of microorganisms which increased, it causes food poisoning. In order to proliferate microorganisms, in addition to the presence of nutrients and an appropriate temperature, the presence of an appropriate amount of water is also indispensable. However, it's not all the water in pet food that microbes are able to use, but the moisture known as "free water."

Moisture in pet food is broadly classified into "bound water" and "free water" according to its state of existence.

"Bound water" is water that binds to other ingredients in pet food (proteins, carbohydrates, etc.) through hydrogen bonds, and the movement of molecules is bound. Therefore, "bound water" will not freeze at 0°C, and it will not be easily vaporized at high temperatures, and will not be used by microorganisms.

On the other hand, "free water" refers to water whose molecules can move freely, and is expressed by an index of water activity. "Water activity" refers to the value obtained by dividing the water vapor pressure of food under the same conditions by the water vapor pressure of pure water. Water activity has a great influence on the oxidation of lipids and the growth of microorganisms present in pet food.

Water activity (Aw) = P/P ₀

P: water vapor pressure of pet food

P ₀ : Water vapor pressure of pure water

The pet food in this embodiment can be in the form of small grains that pets can fill their mouths with one mouthful, or in the shape of large grains that pets can bite multiple times. The longest diameter of pet food is preferably 1 mm to 200 mm, more preferably 1 mm to 150 mm , and more preferably 3 mm to 40 mm. In addition, the shortest diameter of the pet food is preferably 1 mm to 100 mm, more preferably 1 mm to 50 mm, and even more preferably 3 mm to 30 mm.

In this specification, regarding the average major diameter of the granules or small pieces, 20 granules or small pieces were randomly taken out, the longest diameter was measured with a caliper, and the average value thereof was taken as the average long diameter. Moreover, the shortest diameter in the direction perpendicular|vertical to the longest diameter direction was measured, and these average values were made into the average short diameter.

The average major diameter of the pet food according to the present embodiment is preferably 1 mm to 200 mm, more preferably 1 mm to 150 mm, and even more preferably 3 mm to 40 mm.

In addition, the average minor axis of the pet food according to the present embodiment is preferably 1 mm to 100 mm, more preferably 1 mm to 50 mm, and even more preferably 3 mm to 30 mm.

It should be noted that the major axis and minor axis of the particles or small pieces can also be measured by a micrometer, image analysis, or the like.

"Water Absorption"

The pet food of this embodiment absorbs 30% by mass or more of water relative to 100% by mass of the pet food when immersed in water for 5 seconds. Hereinafter, the "amount of water absorbed by the pet food" is also referred to as "amount of water absorption" or "water absorption rate". Specifically, the water absorption rate when immersed in water for 5 seconds is the ratio of the increase in mass of the pet food when the pet food is immersed in water for 5 seconds to the original mass of the pet food.

In this specification, typically, the temperature of water when water absorption is measured refers to a value measured with water at 20°C. For example, it may be a value measured with water at 5°C to 60°C, or may be measured at 15°C. Value measured in water at ~30°C. The lower the temperature, the lower the water absorption. Therefore, if the water absorption for 5 seconds measured with water at a lower temperature exceeds the above-mentioned preferable value, it can be said that the water absorption of the pet food is higher.

The pet food to be measured for water absorption can be obtained through the following steps.

(Step 1A) One pet food to be measured is selected.

(Step 2A) Measure the mass of one grain with an electronic balance.

(Step 3A) The particles are pinched with tweezers and immersed in water.

(Step 4A) After 5 seconds had elapsed, the pellets were taken out of the water.

(Step 5A) After Step 4A, the pellets taken out were left to stand for 5 seconds, and then the pellets were rolled on a sieve (mesh 1 mm) to remove water adhering to the pellet surface.

(Step 6A) Measure the mass of one grain after immersion with an electronic balance.

The amount of water absorption can be obtained by subtracting the mass of the pet food in (step 2A) from the mass of the pet food after (step 6A) and dividing this value by the mass of the pet food in (step 2A) as shown in the following formula (1). Find out.

5 seconds water absorption (mass %)=(mass (g) of pet food after (process 6A)-mass (g) of pet food of (process 2A))/mass (g) of pet food of (process 2A) )×100…(1)

In this embodiment, when immersed in water for 5 seconds, 30% by mass or more of water is absorbed relative to 100% by mass of the pet food, preferably 50% by mass or more of water is absorbed, more preferably 80% by mass or more of water is absorbed, More preferably, it absorbs 130% by mass or more of water.

The pet food of this embodiment can also absorb 40% by mass or more of water relative to 100% by mass of the pet food when immersed in water for 30 seconds.

In the above (step 4A), by changing "5 seconds" to "30 seconds", the pet food to be measured for the amount of water absorption can be obtained.

In this embodiment, when immersed in water for 30 seconds, it absorbs preferably 40% by mass or more of water, more preferably 60% by mass or more of water, and even more preferably 100% by mass or more of water relative to 100% by mass of the pet food. .

The pet food according to the present embodiment can absorb 50% by mass or more of water relative to 100% by mass of the pet food when immersed in water for 60 seconds.

In the above (step 4A), by changing "5 seconds" to "60 seconds", the pet food to be measured for the amount of water absorption can be obtained.

In this embodiment, when immersed in water for 60 seconds, it absorbs preferably 50% by mass or more of water, more preferably 70% by mass or more of water, and even more preferably 120% by mass or more of water relative to 100% by mass of the pet food. water.

"Hardness (hardness) of pellets of pet food"

In this embodiment, the hardness of the pet food granules immersed in water for 5 seconds is preferably 50.0N or less, more preferably 40.0N or less, still more preferably 30.0N or less, particularly preferably 20.0N or less.

In this embodiment, the "hardness of pet food pellets immersed in water for 5 seconds" is a value obtained by measuring the surface with the lowest surface open area ratio of the surface obtained by projecting the pet food in one direction. . The "surface opening area ratio" and its measurement method will be described later in the "surface opening area ratio of the first surface".

In this specification, the hardness of a pet food is the value obtained by the following measuring method.

Using a compression tester (texture analyzer, model: EZ-SX, manufactured by Shimadzu Corporation), the breaking force when the pet food was compressed at a constant compression speed was measured.

Specifically, one pet food to be measured was placed on a tray, and the test force was measured while pressing the plunger vertically at a constant speed from directly above. The peak value (maximum value) of the test force is read as the value of the breaking force. The measurement was repeated for 10 pet foods, and the average value was calculated.

The value of breaking force (unit: kgw) measured by the above-mentioned compression testing machine is multiplied by 9.8 to convert the unit into Newton (N).

Measurement conditions are as follows.

Plunger: width 10mm, length 20mm, front end 1mm thick, wedge-shaped plunger

Platform: flat tray with a diameter of 100mm

Compression speed: 60mm/min

The lowest point of the plunger: Set to press 70% to 90% of the thickness (height) of the pet food

Measuring temperature: 25°C

The pet food dipped in water to be measured for hardness can be obtained by the same steps as the above (step 1A) to (step 5A) for obtaining the "pet food to be measured for water absorption".

With regard to the hardness of the pet food according to the present embodiment, the hardness of the pet food is measured within 20 seconds after removing the water adhering to the grain surface in the above (step 5A). It is preferable to measure the hardness of the pet food within 10 seconds after removing the water adhering to the particle surface in the above (step 5A).

In this embodiment, the hardness of the pellets of the pet food immersed in water for 60 seconds is preferably 20.0N or less, more preferably 15.0N or less, even more preferably 10.0N or less.

"Volume Expansion Ratio of Dough for Pet Food"

When the pet food according to the present embodiment is immersed in water for 5 seconds, it is preferable that the dough expands by 5% by volume or more relative to 100% by volume of the dough of the pet food before being immersed in water (hereinafter, the above-mentioned volume expansion rate is also referred to as "Dough volume expansion rate after soaking for 5 seconds"), more preferably 10% by volume or more, further preferably 20% by volume or more, particularly preferably 25% by volume or more.

If the volume expansion rate of the dough after soaking for 5 seconds is within the above-mentioned preferred range, the pet food can easily absorb water in a short time, and it is easy to provide pet food with desired hardness according to the type and age of the pet to be fed.

When the pet food according to the present embodiment is immersed in water for 60 seconds, it is preferable that the dough expands by 5% by volume or more relative to 100% by volume of the dough of the pet food before being immersed in water (hereinafter, the above-mentioned volume expansion rate is also referred to as "Dough volume expansion rate after soaking for 60 seconds"), more preferably 10% by volume or more, more preferably 20% by volume or more, particularly preferably 25% by volume or more.

If the volume expansion rate of the dough after soaking for 60 seconds is in the above-mentioned preferred range, the pet food can easily absorb water in a short time, and it is easy to provide pet food with desired hardness according to the type and age of the pet to be fed.

In the present embodiment, the "pet food dough" in the "volume expansion ratio of pet food dough" refers to the portion of the food granules other than the opening portion. However, in the "volume expansion rate of dough of pet food", the water absorbed by the dough is not included in the dough when the pet food is immersed in water. In addition, in this specification, "open cell" means the fine hole which exists in the surface and inside of a pet food. This hole may be a hole in which a plurality of holes are connected as communicating holes.

Specifically, the volume expansion ratio of the dough when the pet food was immersed in water for 5 seconds or 60 seconds was calculated by the following formulas (2) to (3).

Dough expansion volume after dipping (mm ³ ) = dough volume after dipping (mm ³ ) - dough volume before dipping (mm ³ ) - water absorption (mg)...(2)

Dough volume expansion rate (%)=(dough volume before dipping (mm ³ )+dough expansion volume after dipping (mm ³ ))/dough volume before dipping (mm ³ )...(3)

In the present embodiment, the dough volumes before and after immersion in the above formulas (2) to (3) are measured in the following procedure.

(Step 1B) One pet food to be measured is selected.

(Step 2B) Using an X-ray CT apparatus (for example, CosmoScan FX (manufactured by Rigaku Corporation)), calculate the volume of the pellets before immersion.

(Step 3B) The pellets are pinched with tweezers and immersed in water.

(Step 4B) After 5 seconds or 60 seconds have elapsed, the pellets are taken out of the water.

(Step 5B) After step 4B, the pellets taken out were left to stand for 5 seconds, and then the pellets were rolled on a sieve (mesh 1 mm) to remove water adhering to the pellet surface.

(Step 6B) Using an X-ray CT apparatus, calculate the volume of the impregnated pellets.

In this embodiment, the CT images in the above-mentioned steps 2B and 6B adopt the following imaging conditions.

(Conditions for capturing CT images)

Tube voltage: 90kV

Tube current: 88μA

Irradiation time: 2 minutes

Resolution: 50μm

FOV (Field of View): 25.6mm×25.6mm×25.6mm

matrix: 512×512×512

In the above steps 2B and 6B, the dough area in each CT cross-sectional image is calculated by the following procedure.

(ib) Using image analysis software (for example, Fiji), X-ray CT images are binarized (maximum entropy method). In each particle cross-section image, the background value was subtracted to calculate the dough area.

Under the above conditions, since the CT image is measured by dividing the FOV (Field of View) into 512 equal parts, one CT cross-sectional image can be regarded as having a thickness of 50 μm. Therefore, if the dough area of one CT cross-sectional image is multiplied by the thickness of 50 μm, it becomes the dough volume of one CT cross-sectional image, and by adding the dough volumes of all the CT cross-sectional images, one can be calculated. The dough volume of the food particle.

"Volume Change Rate of Open Cells in Pet Food"

When the pet food of this embodiment is immersed in water for 5 seconds, the open pore volume ratio is preferably 85% or less relative to the 100% open pore volume ratio of the pet food before immersion in water (hereinafter, the above-mentioned open pore volume The ratio of change is called "opening volume change rate after immersion for 5 seconds"), more preferably 80% or less, further preferably 75% or less, particularly preferably 70% or less.

If the opening volume change rate after immersion for 5 seconds is within the above-mentioned preferred range, the pet food can easily absorb water in a short time, and it is easy to provide pet food with desired hardness according to the type and age of the pet to be fed.

When the pet food of this embodiment is immersed in water for 60 seconds, the open pore volume ratio is preferably 80% or less relative to the 100% open pore volume ratio of the pet food before immersion in water (hereinafter, the above-mentioned open pore volume The ratio of change is called "opening volume change rate after immersion for 60 seconds"), more preferably 75% or less, further preferably 70% or less, particularly preferably 65% or less.

If the opening volume change rate after immersion for 60 seconds is within the above-mentioned preferred range, the pet food can easily absorb water in a short time, and it is easy to provide pet food with desired hardness according to the type and age of the pet to be fed.

In the present embodiment, "open cells of the pet food" refers to the hollow portion in which the dough does not exist in the food grains. In addition, the "open cell volume ratio" refers to the ratio (%) of the open cell volume to the volume of the whole food grain.

Specifically, the opening volume change rate when the pet food was immersed in water for 5 seconds or 60 seconds was calculated by the following formulas (4) to (6).

Open cell volume (mm ³ ) = particle volume (mm ³ ) - dough volume (mm ³ )...(4)

Open pore volume ratio (%) = open pore volume (mm ³ )/particle volume (mm ³ )×100...(5)

Open pore volume change rate (%) = open pore volume rate after immersion (%) / open pore volume rate before immersion (%) × 100...(6)

The particle volume and dough volume in the above-mentioned formula (4) follow the same steps and conditions as the dough volume before and after immersion measured when calculating the above-mentioned "dough volume expansion rate" (the steps 1B to 6B), using an X-ray CT device and Image analysis software is used to perform the measurement according to the following steps (ib) to (iiib).

(ib) Using image analysis software (for example, Fiji), X-ray CT images are binarized (maximum entropy method). In each particle cross-section image, the background value was subtracted to calculate the dough area.

(iib) In each CT cross-sectional image, use Fill holes and Dilate/Erode to process and fill the openings and subtract the background value to calculate the area of the entire particle.

(iiib) The open cell area can be calculated by subtracting the dough area calculated in the step (ib) from the area of the entire particle calculated in the step (iib).

Under the above conditions, since the CT image is measured by dividing the FOV (Field of View) into 512 equal parts, one CT cross-sectional image can be regarded as having a thickness of 50 μm. Therefore, if the dough area, grain area, and opening area of one CT cross-sectional image are multiplied by a thickness of 50 μm, the dough volume, grain volume, and opening volume of one CT cross-sectional image can be obtained. By adding the volumes, it is possible to calculate the dough volume, granule volume, and pore volume of one food granule to be measured.

"Dough Area Expansion Ratio in the Cross Section of the Central Part of Pet Food Granules"

When the pet food of this embodiment is immersed in water for 5 seconds, the dough area is preferably increased by 45 area % or more (hereinafter, The above-mentioned area increase rate is also referred to as "the central cross-sectional dough area change rate after immersion for 5 seconds"), more preferably 50 area% or more, still more preferably 60 area% or more, still more preferably 85 area% or more.

If the rate of change of dough area at the center cross section after dipping for 5 seconds is within the above-mentioned preferable range, it is easy to absorb water into the inside of the food granules in a short time, and it is easy to provide pets with desired hardness according to the type and age of the pets to be fed. food.

After dipping for 5 seconds, the dough area change rate of the central cross section was calculated by the following formula (7).

After dipping for 5 seconds, the rate of change in dough area of the central cross-section (%) = Dough area of the cross-section of the central portion of the pellet after dipping (mm ² )/Dough area of the cross-section of the central portion of the pellet before dipping (mm ² )× 100…(7)

The area of the dough before and after immersion in the above formula (7) was measured by the following procedure. It should be noted that, in the above formula (7), the area of the dough after immersion also includes the area of absorbed water.

(Step 1C) One pet food to be measured is selected.

(Step 2C) Using an X-ray CT apparatus (for example, CosmoScan FX (manufactured by Rigaku Corporation)), the area of the dough before dipping is calculated.

(Step 3C) The particles are pinched with tweezers and immersed in water.

(Step 4C) After 5 seconds or 60 seconds have elapsed, the pellets are taken out of the water.

(Step 5C) After step 4B, the pellets taken out were left to stand for 5 seconds, and then the pellets were rolled on a sieve (mesh 1 mm) to remove water adhering to the pellet surface.

(Step 6C) Using an X-ray CT apparatus, the area of the dough after immersion is calculated.

In the present embodiment, the following imaging conditions are used for the CT images in the above steps 2C and 6C.

(Conditions for capturing CT images)

Tube voltage: 90kV

Tube current: 88μA

Irradiation time: 2 minutes

Resolution: 50μm

FOV (Field of View): 25.6mm×25.6mm×25.6mm

matrix: 512×512×512

In the above steps 2C and 6C, the dough area in each CT cross-sectional image is calculated by the following procedure.

(ic) Using image analysis software (eg, Fiji), binarize the X-ray CT image (maximum entropy method). In each particle cross-section image, the background value was subtracted to calculate the dough area.

In this embodiment, "the cross-section of the central part of the pet food granule" in "the change rate of the dough area of the central cross-section after immersion for 5 seconds" refers to: placing food granules, measuring n pieces perpendicular to the plane from one direction In the case of CT images, when the CT image that starts to capture food particles is the xth image, and the CT image that ends with food particles is the yth image, (y-(x-1))×1/3+x～ A cross section within the range of (y-(x-1))×2/3+x. Here, x<n, y<n, and x<y.

For example, in the case of measuring with the above CT image shooting conditions, ie, FOV: 25.6mm×25.6mm×25.6mm, matrix: 512×512×512, the 100th CT image starting to capture food particles, When the CT image with food particles in it is the 399th, (399-(100-1)×1/3+100～(399-(100-1)×2/3+100=200th～300th The CT image of Zhang can be "a cross-section of the central part of a grain of pet food".

"Changing rate of opening area in the cross-section of the central part of the pellet of pet food"

When the pet food of this embodiment is immersed in water for 5 seconds, the open area ratio is preferably 80% or less ( Hereinafter, the change ratio of the above-mentioned opening area ratio is also referred to as "the change ratio of the central cross-sectional opening area after immersion for 5 seconds"), more preferably 75% or less, further preferably 70% or less, particularly preferably 65% the following.

If the change rate of central cross-sectional opening area after immersion for 5 seconds is within the above-mentioned preferred range, it is easy to absorb water into the inside of the food pellets in a short time, and it is easy to provide the desired hardness according to the type and age of the pet to be fed. pet food.

After dipping for 5 seconds, the rate of change in the central cross-sectional opening area was calculated by the following formulas (8) to (10).

Open cell area (mm ² ) of the cross section of the central part of the granule = grain area (mm ² ) of the cross section of the central part of the granule - dough area (mm ² )...(8)

Opening area ratio (%) = opening area (mm ² )/particle area (mm ² )×100...(9)

After immersing for 5 seconds, the change rate of central cross-section opening area (%)=opening area rate after dipping (%)/opening area rate before dipping (%)...(10)

The particle area and the dough area in the above formula (8) follow the same steps and conditions as the dough area before and after immersion measured when the above-mentioned calculation "the rate of change of the central section dough area after immersion for 5 seconds" (the steps 1C to 6C ), measured by the following steps (ic) to (iiiic) using an X-ray CT apparatus and image analysis software. It should be noted that, in the above formula (8), the area of the dough after immersion also includes the area of absorbed water.

(ic) Using image analysis software (eg, Fiji), binarize the X-ray CT image (maximum entropy method). In each particle cross-section image, the background value was subtracted to calculate the dough area.

(iic) In each CT cross-sectional image, use Fill holes and Dilate/Erode to process the buried openings and subtract the background value to calculate the overall area of the particles.

(iiic) The open cell area can be calculated by subtracting the dough area calculated in the step (ic) from the area of the entire granule calculated in the step (iic).

The "cross-section of the central part of the pet food pellet" in the "change rate of central cross-sectional opening area after immersion for 5 seconds" and "the cross-section of the central cross-sectional dough area after immersion for 5 seconds" in the "pet food particle The cross-section of the central part of the "is the same.

"Particle density change rate of pet food"

When the pet food of this embodiment is immersed in water for 5 seconds, the particle density of the pet food before immersion in water is 100%, and the particle density is preferably increased by 10% or more (hereinafter, the change ratio of the above particle density is also referred to as "Rate of particle density change after immersion for 5 seconds") is more preferably 15% or more, further preferably 20% or more.

If the particle density change rate after immersion for 5 seconds is within the above preferred range, the pet food can easily absorb water in a short time, and it is easy to provide pet food with desired hardness according to the type and age of the pet to be fed.

When the pet food of this embodiment is immersed in water for 60 seconds, the particle density of the pet food before immersion in water is 100%, and the particle density is preferably increased by 15% or more (hereinafter, the change ratio of the above particle density is also referred to as "The rate of change in particle density after immersion for 60 seconds") is more preferably 20% or more, further preferably 25% or more.

If the particle density change rate after immersion for 60 seconds is within the above preferred range, the pet food can easily absorb water in a short time, and it is easy to provide pet food with desired hardness according to the type and age of the pet to be fed.

The particle density change rate when the pet food was immersed in water for 5 seconds or 60 seconds was calculated by the following formulas (11) to (13).

Particle volume (L) = particle volume (mm ³ )/1000000...(11)

Particle density (g/L) = particle mass (g)/particle volume (L)...(12)

Particle density change rate (%) = particle density after impregnation (g/L) / particle density before impregnation (g/L) × 100...(13)

The particle mass in the above-mentioned formula (12) can be measured in the same procedure as Steps 1A to 6A in the measurement of the above-mentioned "water absorption rate".

In addition, the particle volume in the above formula (12) is obtained through the same steps and conditions as the particle volume measured when calculating the above-mentioned "opening volume change rate" (the above-mentioned steps 1B to 6B), using an X-ray CT device and image analysis software, The area of the entire particle (particle area) is measured by the above steps (ib) to (iib). Under the above conditions, since the CT image is measured by dividing the FOV (Field of View) into 512 equal parts, one CT cross-sectional image can be regarded as having a thickness of 50 μm. Therefore, if the particle area of one CT cross-sectional image is multiplied by the thickness of 50 μm, it becomes the particle volume of one CT cross-sectional image, and by adding the volumes of all CT cross-sectional images, one particle to be measured can be calculated. The particle volume of the food particle.

As mentioned above, the pet food of this embodiment can obtain the pet food of different hardness by changing the time to absorb water (time to immerse in water). In addition, the pet food according to the present embodiment can obtain pet food having different water absorption amounts by changing the time for absorbing water (time for immersion in water). That is to say, by making pet food with a moisture content of 15% or less absorb water, the composition of the pet food can be changed, approaching the composition of soft food with a moisture content of about 25% to 35%, the composition of semi-moist food, or the composition of a moisture content of Composition of about 75% wet food. In such a case, the temperature of the water in which the pet food is soaked may be 35°C to 60°C, 40°C to 60°C, or 45°C from the viewpoint of shortening the water absorption time and the handleability of the feeder. ~60°C.

If the water content of the pet food is low, the water activity tends to be low, so the oxidation of lipids and the growth of microorganisms present in the pet food can be suppressed. Therefore, the preservation and handling properties of pet food are improved. Pet food, on the other hand, inherently has a low moisture content which means it is drier, so the pet food particles become harder.

The pet food of this embodiment originally has a water content as low as 15%, but it can absorb water in a short time and soften the hardness in a short time.

Depending on the state of health and growth of dogs and cats, the preference for hardness of pet food may vary. Therefore, as in this embodiment, if the feeder adds water at the timing of feeding, soft pet food pellets can be made in a short time, and the feeder can change the pet food according to the health status, growth status, etc. of dogs and cats. Pet food for the hardness your pet prefers.

The pet food according to the present embodiment is a dry pet food during transportation and storage, and therefore has excellent storage stability and handling properties. Furthermore, the composition of the pet food according to the present embodiment can be changed into a soft dry type, a semi-moist type, or a wet type as desired during feeding, so palatability can be improved.

"Surface Opening Area Ratio of Surface 1"

In the pet food according to this embodiment, the surface open area ratio of the first surface obtained by projecting the pet food in the first direction may be 10% or more.

The first direction refers to an arbitrary direction. For example, when the pet food according to the present embodiment is placed on the measuring platform of a digital microscope, and an image of the surface (top surface) of the pet food opposite to the mounting surface is taken, the digital microscope is directed toward the top surface of the pet food. The direction of the surface is the first direction. In addition, the image of the top surface of the pet food captured by the digital microscope becomes the first surface on which the pet food is projected.

The surface open area ratio of the first surface of the pet food according to this embodiment may be 10% or more, preferably 12% or more, more preferably 16% or more, still more preferably 20% or more, particularly preferably 25% or more.

On the other hand, the surface open area ratio of the first surface of the pet food according to the present embodiment is preferably 60% or less, more preferably 55% or less, and still more preferably 50% or less.

For example, the surface open area ratio of the first surface of the pet food according to the present embodiment is preferably 10% to 60%, more preferably 12% to 60%, even more preferably 16% to 55%, Especially preferably 20% or more and 50% or less, most preferably 25% or more and 50% or less.

In this specification, "surface opening area ratio" refers to the measurement by taking an image of the surface of pet food using a digital microscope (trade name "VHX-7000", manufactured by KEYENCE CORPORATION) and using the image. /Ruler tool for automatic area measurement (particle counting), except that the equivalent circle diameter is less than 50 μm, and the value obtained by measuring the surface open area ratio.

More specific operation steps are as follows.

(i) The magnification of the digital microscope is set so that the entire first surface of the pet food placed on the measuring table is reflected (for example, set to 20 magnifications).

(ii) The set value of the epi-illumination is set to a value between 100 and 255 that can best see the opening.

(iii) In the digital microscope measurement/ruler tool automatic area measurement (particle counting), the extraction method is set to "brightness (standard)". Next, set the extraction area of the first side of the pet food.

(iv) If the circle-equivalent diameter is less than 50 μm, the opening ratio of the first surface of the pet food can be measured by performing the measurement/scale tool automatic area measurement (particle counting) of a digital microscope.

"Surface Opening Area Ratio of Other Surfaces"

In the pet food according to the present embodiment, the surface of the pet food projected in a direction other than the first direction (hereinafter also referred to as "other surface") preferably has a surface open area ratio of 8% or less. That is, in the pet food of the present embodiment, it is preferable that a portion with a large number of pores and a portion with a small number of pores are mixed on the surface of the pet food.

The surface open area ratio of the other surface of the pet food of this embodiment is preferably 8% or less, more preferably 4% or less, still more preferably 2% or less, and may be 0%.

"Surface Opening Area Ratio of Surfaces 2 and 3"

The pet food of the present embodiment is preferably on the A side (also referred to as the + side, the first side or one side) in the second direction intersecting the first direction in addition to the first surface of the above-mentioned pet food. ) is a surface obtained by projecting the pet food as a second surface, and the pet food is obtained by projecting the pet food to the B side (also referred to as the - side, the second side or the other side) in the second direction. When the surface is set as the third surface, at least one of the second surface and the third surface has a surface open area ratio of 10% or more. That is, the pet food of the present embodiment preferably has a portion with a large number of openings on the surface of the pet food.

Here, the second direction typically refers to a direction "orthogonal" to the first direction, but is not limited to the direction perpendicular to the first direction, and may refer to a surface that intersects the first direction and faces the pet food. Orthogonal to such a predetermined direction.

For example, as a specific example of the case where the second direction is not a direction perpendicular to the first direction, in the case where the pet food of the present embodiment is tetrahedral and the bottom surface is set as the first surface, the tetrahedral shape The direction perpendicular to the sides of the pet food becomes the second direction.

In addition, when the pet food of the present embodiment is not in a shape such as a spherical shape or a cylindrical shape, the second direction means a direction "orthogonal" to the first direction.

The preferable ranges of the surface opening area ratios of the second surface and the third surface are the same as the preferable ranges of the surface opening area ratios of the above-mentioned first surface.

In the pet food of the present embodiment, in addition to the above-mentioned first surface of the pet food, it is preferable that the surface open area ratios of the second surface and the third surface of the pet food are both 10% or more.

The pet food of this embodiment preferably has a surface area ratio of 10% or more on the first surface, the second surface, and the third surface, and at least one surface other than the first surface, the second surface, and the third surface The surface open area ratio is 8% or less.

More specifically, the pet food according to the present embodiment preferably has a surface area ratio of 10% or more and 60% or less on the surface of the first surface, the second surface, and the third surface. The surface opening area ratio of at least one surface other than the third surface is 8% or less, more preferably the surface opening area ratios of the first surface, the second surface, and the third surface are all 12% or more and 60% or less, and The surface open area ratio of at least one surface other than the first surface, the second surface, and the third surface is 4% or less, and it is more preferable that the surface open area ratios of the first surface, the second surface, and the third surface are uniform. It is 16% or more and 55% or less, and the surface opening area ratio of at least one surface other than the first surface, the second surface, and the third surface is 4% or less, more preferably the first surface and the second surface And the surface open area ratio of the third surface is 20% or more and 50% or less, and the surface open area ratio of at least one surface other than the first surface, the second surface, and the third surface is 4% or less It is particularly preferable that the surface open area ratios of the first surface, the second surface, and the third surface are all 25% or more and 50% or less, and at least one surface other than the first surface, the second surface, and the third surface The surface open area ratio of 4% or less, most preferably the surface open area ratios of the first surface, the second surface and the third surface are all 25% or more and 50% or less, and, except for the first surface, the second surface And the surface open area ratio of at least one surface other than the third surface is 2% or less.

Furthermore, in the above-mentioned pet food, "at least one surface other than the first surface, the second surface, and the third surface" is preferably "two surfaces other than the first surface, the second surface, and the third surface".

"shape"

The shape of the pet food according to the present embodiment is not particularly limited as long as it is a shape suitable for pets to eat.

For example, all shapes such as sphere, ellipsoid (go piece shape), bullet shape, cylinder shape, polygonal column shape, hexahedron shape (plate shape), clover shape, heart shape, star shape, and cross shape can be applied. Among them, from the viewpoint of obtaining the effect of the present invention more easily, the shape of a column, polygonal column, or hexahedron is preferable, and the shape of a hexahedron is more preferable.

"hardness"

The hardness of the pet food according to the present embodiment is preferably 60N or less, more preferably 50N or less, even more preferably 40N or less.

In the present embodiment, the "hardness of pet food pellets" is a value obtained by measuring the surface with the lowest surface open area ratio of the surface obtained by projecting the pet food in one direction. The "surface opening area ratio" and its measurement method are the same as those described in the above-mentioned "surface opening area ratio of the first surface".

On the other hand, the hardness of the pet food according to the present embodiment is preferably 6N or higher, more preferably 8N or higher, and even more preferably 10N or higher.

In this specification, the hardness of a pet food is the value obtained by the following measuring method.

Using a compression tester (texture analyzer, model: EZ-SX, manufactured by Shimadzu Corporation), the breaking force when the pet food was compressed at a constant compression speed was measured.

Specifically, one pet food to be measured was placed on a tray, and the test force was measured while pressing the plunger vertically at a constant speed from directly above. The peak value (maximum value) of the test force is read as the value of the breaking force. The measurement was repeated for 10 pet foods, and the average value was calculated.

The value of the breaking force (unit: kgw) measured by the above-mentioned compression testing machine was multiplied by 9.8 to convert the unit into Newton (N).

The measurement conditions are as follows.

Plunger: width 10mm, length 20mm, front end 1mm thick, wedge-shaped plunger

Platform: flat tray with a diameter of 100mm

Compression speed: 60mm/min

The lowest point of the plunger: Set to press 70% to 90% of the thickness (height) of the pet food

Measuring temperature: 25°C

In the pet food according to the present embodiment, the hardness of the first surface is preferably the value of the above-mentioned preferable hardness. That is, in the method for measuring the hardness of pet food described above, the value (hardness) when the test force is measured while pressing the plunger against the first surface of the pet food according to the present embodiment is preferably 6N or more and 60N or less, more preferably 6N or more and 60N or less. 8N to 50N, more preferably 10N to 40N.

In addition, when the pet food of the present embodiment has other surfaces with a surface opening area ratio of 8% or less, the value of the test force (hardness ) is preferably not less than 15N and not more than 70N, more preferably not less than 20N and not more than 60N, still more preferably not less than 25N and not more than 50N.

"raw material"

As raw materials of the pet food of this embodiment, known powder raw materials and liquid raw materials in the manufacture of pet food can be used, and the following pet food raw materials may be used alone or in combination of two or more.

Specific examples of powdery and liquid raw materials include grains (corn, sorghum, wheat, barley, brown rice, oats, rye, wheat flour, rice flour, corn flour, wheat bran, rice, wheat germ, wheat gluten, Corn gluten feed, corn gluten meal, bread flour, etc.); potatoes (sweet potatoes, potatoes, etc.); beans (soybeans, broad beans, adzuki beans, peas, defatted soybeans, soybean meal, soybean flour, soybean flour, soybean protein, soybean meal, etc.); starches (corn starch, potato starch, tapioca starch, wheat starch, rice starch, potato starch, sweet potato starch, sago starch, etc.); meat (beef, pork, lamb, mutton, chicken, turkey , poultry and other meat, liver and other offal, their meat extract powder, liquid, and their processed pork meal, chicken meal, beef meal, their mixed meal, etc.); fish and shellfish (tuna, skipjack fish, salmon, cod, horse mackerel, sardines and other fish, shrimp, crab and other crustaceans, shellfish, and their processed fish meal, fish extract powder, liquid, dried bonito, etc.); eggs (eggs (whole eggs, dried whole eggs, egg yolks, egg whites), etc.; vegetables (carrots, cabbage, green peas, pumpkins, beet pulp, etc.), seeds; mushrooms; sugars (sugar, glucose, fructose, high-fruit syrup, oligosaccharides, starch syrup, syrup, molasses, honey, etc.); milk (whole milk, skimmed milk, whole milk powder, skimmed milk powder, whey, cheese, butter, cream, etc.); oils (animal fats (butter, lard, chicken oil, fish oil, etc.); vegetable fats (soybean oil, sesame oil, germ oil, palm oil, corn oil, olive oil, coconut oil, etc.), fatty acids, etc.); dry yeast, its extract powder, liquid; dietary fiber (cellulose, etc.); vanilla; vitamins; minerals; amino acids; sweeteners; colorants; preservatives; thickening stabilizers; processed starch; antioxidants; pH regulators; seasonings material; emulsifier; leavening agent; spices, etc.

Among the above, the pet food of the present embodiment preferably contains cereals and meat.

The content of the grains in the pet food according to the present embodiment is preferably 10% to 90% by mass, more preferably 15% to 80% by mass, and even more preferably 20% to 70% by mass based on the total amount of the pet food.

The content of meat in the pet food according to the present embodiment is preferably 1% by mass to 40% by mass, more preferably 3% by mass to 30% by mass, and even more preferably 5% by mass to 20% by mass relative to the total amount of the pet food. .

Among the above, (a) grains, (b) beans, (c) meat, (d) fish and shellfish, (e) dietary fiber, and (f) dry yeast are preferred as the composition of the pet food of this embodiment. , its extract powder, liquid, (g) mixture of vegetables, (h) vitamins and minerals, (i) oils and fats. Coloring agents; antioxidants; and seasonings may also be contained in this mixture as needed.

In addition, as the composition of the pet food in this embodiment, (a) cereals, (b) beans, (c) meat, (d) fish and shellfish, (e) dietary fiber, (f) dried Yeast, its extract powder, liquid, (g) vegetables, (h) vitamins and minerals, (i) fats, (j) starches, (k) eggs, (l) sugars, ( m) Milk mixtures. Coloring agents; preservatives; thickening stabilizers; antioxidants; pH regulators; seasonings; emulsifiers;

The compounding example of the pet food of this embodiment is as follows.

Adjusted to cereals (10% to 90% by mass), beans (0 to 40% by mass), meat (0 to 40% by mass), fish and shellfish (0 to 40% by mass), dietary fiber (0 to 20% by mass), % by mass), dry yeast, its extract powder, liquid (0 to 10% by mass), vegetables (0 to 20% by mass), vitamins and minerals (0 to 10% by mass), fats and oils (0 to 10% by mass 20% by mass), coloring agent (0 to 5% by mass), antioxidant (0 to 5% by mass), seasoning (0 to 5% by mass).

Hereinafter, shape examples (1) and (2) of food grains will be described in detail as specific embodiments of the pet food according to the present embodiment, using the drawings.

In the following description, an orthogonal coordinate system of X, Y, and Z will be used for description as needed. In this case, the Z direction represents the height direction (gravity direction). The two directions perpendicular to the Z direction are the X direction and the Y direction. The arrow side in the figure will be described as a plus (+) side, and the side opposite to the arrow will be described as a minus (−) side. For example, the +Z side corresponds to the upper side in the height direction, and the -Z side corresponds to the lower side in the height direction.

(Example (1) of the shape of the food grains of the pet food of the present embodiment)

Pet food C10 will be described in detail using FIG. 1 as an example (1) of the shape of food grains of the pet food according to this embodiment.

Pet food C10 is a hexahedral pet food. In the pet food C10, the four side surfaces (side peripheral surfaces) of the pet food C10 have more openings 1 than the top surface and the bottom surface.

As shown in FIG. 1 , the first direction coincides with the X direction, the second direction coincides with the Y direction, and the third direction coincides with the Z direction. That is, the two directions perpendicular to the first direction are the second direction and the third direction.

The pet food C10 is a hexahedral pet food, and the two directions perpendicular to the first direction are the second direction and the third direction. Therefore, the pet food C10 is projected on the side A (+X side) of the first direction. One surface C1 corresponds to the side surface on the A side of the pet food C10 in the first direction.

The surface opening area ratio of the first surface C1 obtained by projecting the pet food C10 on the A side (+X side) of the first direction of the pet food C10 is 10% or more.

In the pet food C10, the surface obtained by projecting the pet food C10 on the A side (+X side) in the first direction is the first surface C1. In addition, the surface obtained by projecting the pet food C10 on the B side (-X side) in the first direction is the fourth surface C4.

In the pet food C10, the surface obtained by projecting the pet food C10 on the A side (+Y side) in the second direction perpendicular to the first direction is the second surface C2. In addition, the surface obtained by projecting the pet food C10 on the B side (-Y side) in the second direction perpendicular to the first direction is the third surface C3.

In the pet food C10, the surface obtained by projecting the pet food C10 on the A side (+Z side) in the third direction perpendicular to the first direction is the fifth surface C5. In addition, the surface obtained by projecting the pet food C10 on the B side (-Z side) in the third direction perpendicular to the first direction is the sixth surface C6.

Fig. 2 is a diagram showing surfaces obtained by projecting the pet food C10 in various directions, that is, the first surface C1 to the sixth surface C6.

The first surface C1 to the fourth surface C4 of the pet food C10 are surfaces having a surface open area ratio of 10% or more, and the fifth surface C5 and sixth surface C6 are surfaces having a surface open area ratio of 8% or less.

The preferred ranges of the surface open area ratios of the first surface C1 to the fourth surface C4 in the pet food C10 are as described above, for example, preferably 10% to 60%, more preferably 12% to 60%, More preferably, it is 16% or more and 55% or less, particularly preferably 20% or more and 50% or less, most preferably 25% or more and 50% or less.

The preferred value of the surface open area ratio of the fifth surface C5 and the sixth surface C6 in the pet food C10 is preferably 8% or less, more preferably 4% or less, still more preferably 2% or less, and may be 0%.

In addition, as mentioned above, in the pet food C10, the projected first surface C1 coincides with the side A side of the pet food C10 in the first direction, so it can also be said that the bottom surface and the top surface of the pet food C10 are surface-open The surface with a pore area ratio of 8% or less, and the four side peripheral surfaces are all surfaces with a surface pore area ratio of 10% or more.

In the pet food C10, the first surface C1 to the fourth surface C4 are surfaces with a surface open area ratio of 10% or more, and the fifth surface C5 and sixth surface C6 are surfaces with a surface open area ratio of 8% or less. , but the fourth surface C4 and the second surface C2 or the third surface C3 may be surfaces with a surface opening area ratio of 8% or less. In addition, the fifth surface C5 or the sixth surface C6 may be a surface having a surface opening area ratio of 10% or more.

(Example (2) of the shape of the food grains of the pet food of the present embodiment)

Pet food D10 will be described in detail using FIG. 3 as an example (2) of the shape of food grains of the pet food according to this embodiment.

Pet food D10 is a cylindrical pet food. In the pet food D10, the side peripheral surface has many openings 2, and the top and bottom surfaces of the pet food D10 have few openings 2.

As shown in FIGS. 3 and 4 , the first direction coincides with the X direction, the second direction coincides with the Y direction, and the third direction coincides with the Z direction. That is, the two directions perpendicular to the first direction are the second direction and the third direction.

The surface opening area ratio of the first surface D10 obtained by projecting the pet food D10 on the A side (+X side) of the first direction of the pet food D10 is 10% or more.

In the pet food D10, the surface obtained by projecting the pet food D10 on the A side (+X side) in the first direction is the first surface D1. Moreover, the surface obtained by projecting the pet food D10 to the B side (-X side) of a 1st direction is the 4th surface D4.

In the pet food D10, the surface obtained by projecting the pet food D10 on the A side (+Y side) in the second direction perpendicular to the first direction is the second surface D2. In addition, the surface obtained by projecting the pet food D10 on the B side (-Y side) in the second direction perpendicular to the first direction is the third surface D3.

In the pet food D10, the surface obtained by projecting the pet food D10 on the A side (+Z side) in the third direction perpendicular to the first direction is the fifth surface D5. In addition, the surface obtained by projecting the pet food D10 on the B side (-Z side) in the third direction perpendicular to the first direction is the sixth surface D6.

Since the pet food D10 is cylindrical, only the fifth surface D5 coincides with the top surface of the pet food D10, and the sixth surface D6 coincides with the bottom surface of the pet food D10.

Fig. 4 is a diagram showing surfaces obtained by projecting the pet food D10 in various directions, that is, the first surface D1 to the sixth surface D6.

The first surface D1 to the fourth surface D4 of the pet food D10 are surfaces having a surface opening area ratio of 10% or more, and the fifth surface D5 and the sixth surface D6 are surfaces having a surface opening area ratio of 8% or less.

The preferred ranges of the surface open area ratios of the first surface D1 to the fourth surface D4 in the pet food D10 are as described above, for example, preferably 10% to 60%, more preferably 12% to 60%. Below, more preferably 16% or more and 55% or less, particularly preferably 20% or more and 50% or less, most preferably 25% or more and 50% or less.

The preferred value of the surface open area ratio of the fifth surface D5 and the sixth surface D6 in the pet food D10 is preferably 8% or less, more preferably 4% or less, still more preferably 2% or less, and may be 0%.

In addition, as mentioned above, in the pet food D10, only the fifth surface D5 is consistent with the top surface of the pet food D10, and the sixth surface D6 is consistent with the bottom surface of the pet food D10, so the pet food D10 can also be said to be the bottom surface and the top surface. It is a surface with a surface opening area ratio of 8% or less, and the side peripheral surface is a surface with a surface opening area ratio of 10% or more.

(Manufacturing method of pet food)

As the method for producing pet food according to the present embodiment, for example, a method for producing pet food having a step of expanding: extruding the kneaded raw material mixture from an extrusion molding machine to produce making it puffed to obtain puffed dough; a porous step, in which the puffed dough is made porous to obtain a porous dough; and a cutting step, in which, Cut the porous dough.

As a specific example of the pet food manufacturing method according to this embodiment, a pet food manufacturing method 100 will be described in detail using FIG. 5 .

As shown in FIG. 5 , the raw material mixture is kneaded by the extrusion molding machine 101, and the raw material mixture is extruded from the extrusion molding machine to obtain puffed dough sd. The obtained puffed dough sd is transported by the belt conveyor 102 . The conveyed puffed dough sd is made porous by being cooled by the cooling machine 103, and the porous dough pd made porous is obtained. The obtained porous dough pd is cut with a cutter 104 to obtain the pet food PF of this embodiment.

[Puffing process]

The puffing step is a step of extruding and puffing the raw material mixture kneaded by the extruder 101 from the extruder to obtain puffed dough sd.

The extruder 101 is not particularly limited, and a known single-screw or twin-screw extruder or the like can be used.

The temperature of the raw material mixture when the raw material mixture is kneaded by the extruder 101 is, for example, preferably 75°C to 140°C, more preferably 80°C to 135°C, even more preferably 85°C to 130°C.

[Porous process]

The porous making step is a step of making the puffed dough sd porous to obtain porous dough pd.

Specifically, as the porosity-making step, a step of cooling the puffed dough sd with the cooling machine 103 while placing the puffed dough sd under atmospheric pressure is exemplified.

It does not specifically limit as the cooling machine 103, A well-known spot cooler etc. can be used.

[cutting process]

The cutting step is a step of cutting the porous dough pd with the cutter 104 . When cutting the porous dough pd with the cutter 104, the porous dough pd may be cut from the MD, may be cut from the CD, or may be cut from either direction of the MD and the CD. Here, MD (machine direction, machine direction) refers to the direction in which the porous dough pd flows (it can also be said to be the direction in which the puffed dough sd extruded from the extrusion molding machine flows). CD (cross direction, orthogonal direction) means a direction perpendicular to the direction in which the porous dough pd flows.

The temperature of the porous dough pd when the porous dough pd is cut by the cutter 104 is preferably, for example, 70° C. or lower.

By the above method, a pet food having a moisture content of 15% or less and absorbing 30% by mass or more of water relative to 100% by mass of the pet food when immersed in water for 5 seconds can be obtained.

Since the method for producing pet food described above has a porous-making step, the above-mentioned pet food can be easily produced. Specifically, in the conventional method of producing pet food, for example, "Clinical Nutrition for Small Animals 5th Edition" (edited by Michael S. Hand, Craig D. Thatcher, Rebecca L. Remillard, Philip Roudebusg, Bruce J. Novotny, Published by Mark Morris Associates; 2014; p.209-p.215), usually a knife is provided at the exit of the extrusion molding machine, and the raw material mixture is cut by the knife at the moment when the raw material mixture is extruded from the extrusion molding machine. On the other hand, in the pet food manufacturing method of the present embodiment, the pet food is made porous by taking time between extruding the raw material mixture from the extrusion molding machine and cutting it with a knife. Therefore, according to the manufacturing method of the pet food of this embodiment, the said pet food can be manufactured simply.

In the porosity-making step in the pet food manufacturing method 100, the cooling by the cooling machine 103 may be carried out in batches by moving the puffed dough extruded from the extrusion molding machine to the outside of the production line.

In addition, in the porosity-making step in the pet food manufacturing method 100, the puffed dough sd is cooled by the cooling machine 103, but the cooling machine 103 may not be used. That is, it may be a step of cooling the puffed dough sd at room temperature by extending the length of the belt conveyor 102 . For example, the length of the belt conveyor 102 may be adjusted, and the puffed dough sd may be left at room temperature (25° C.) for at least 1 minute, for example, from when it is extruded by the extruder to when it is cut.

<Other manufacturing methods>

The method of producing the pet food of this embodiment may be a method other than the above-mentioned production method, for example, the pet food of this embodiment may be produced using a raw material that generates gas by heating. Specific examples of the raw material for generating gas include sodium bicarbonate and the like.

<Other Embodiments>

According to another embodiment of the present invention, there is provided a pet food (hereinafter also referred to as "the pet food of the second embodiment"), which is a pet food with a moisture content of 15% or less, wherein, at a viscosity of 1.5 dPa·s When immersed in the liquid for 5 seconds, 30% by mass or more of the liquid was absorbed relative to 100% by mass of the pet food.

It should be noted that the pet food of the present embodiment may consist only of the pet food of the above-mentioned second embodiment, or may be a mixture of the pet food of the above-mentioned second embodiment and other pet foods. It does not specifically limit as another pet food, Dry pet food other than the pet food of 2nd Embodiment mentioned above, a raw material, a flake, etc. are mentioned. In the mixture of the pet food of the second embodiment and other pet food, the pet food of the second embodiment may be contained in an amount of 1% or more based on the total amount of the mixture.

Typical examples of the "liquid with a viscosity of 1.5 dPa·s" include soup-type pet food with a viscosity of 1.5 dPa·s, but the present embodiment is not limited thereto. For example, it is also possible to apply a liquid whose viscosity is adjusted to 1.5 dPa·s by mixing a thickener in water.

In the second embodiment, the liquid absorption rate (mass basis) of the liquid with a viscosity of 1.5 dPa·s can be the same as the water absorption rate in the first embodiment except that a liquid with a viscosity of 1.5 dPa·s is used instead of water. To measure.

When the pet food according to the second embodiment is immersed in a liquid with a viscosity of 1.5 dPa·s for 5 seconds, it absorbs 30% by mass or more of the liquid relative to 100% by mass of the pet food, preferably 40% by mass or more. The liquid absorbs more preferably 50% by mass or more of the liquid, still more preferably 65% by mass or more of the liquid.

When the pet food according to the second embodiment is immersed in a liquid with a viscosity of 1.5 dPa·s for 60 seconds, it absorbs 30% by mass or more of the liquid relative to 100% by volume of the pet food, and preferably absorbs 40% by mass or more of the liquid. The liquid absorbs more preferably 50% by mass or more of the liquid, still more preferably 65% by mass or more of the liquid.

In the pet food according to the second embodiment, the hardness of the granules of the pet food immersed in the liquid for 5 seconds is preferably 50.0N or less, more preferably 45.0N or less, still more preferably 40.0N or less, particularly preferably It is below 35.0N.

In the second embodiment, the hardness of the pellets of the pet food can be measured in the same manner as in the first embodiment.

Example

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

(manufacturing of pet food)

<<Test example 1~4>>

With the formulation shown in Table 1, the raw materials constituting the pet food were mixed to obtain a raw material mixture. Water was added to this raw material mixture with a preconditioner, 12 to 25 parts by mass was added to 100 parts by mass of the total amount of the raw material mixture, and the mixture was mixed while heating at 70° C. to 100° C. for 5 seconds to 3 minutes. The heated raw material mixture is put into an extruder, heat-treated at 80°C to 125°C for 10 seconds to 2 minutes while kneading, the starch component is pregelatinized, and discharged from the extruder to obtain Puffed dough. The obtained dough was cooled with a cooler so that the surface temperature of the dough was 70° C. or lower, and a porous dough was obtained. Next, the obtained dough was cut into a hexahedron shape from MD and CD (test example 4 only CD) with a knife to obtain a hexahedron shape (longitudinal 8 mm (X direction) * horizontal 8 mm (Y direction) * height (thickness) 11.5 mm (Z direction)) of the pet food of Test Examples 1 to 4 with openings.

In Test Examples 1 to 4, in order to achieve the pellet density (g/L) shown in Tables 4, 6, 10 and 12, the processing temperatures of the preconditioner and the extruder were adjusted to the temperatures shown in Table 2.

The pet food of Test Examples 1 to 3 has the same form as the pet food C10 shown in FIG. 1 , and the surface cut with a knife is the side peripheral surface. In addition, the first surface of the pet food of test examples 1-3 is consistent with the first surface C1 of the pet food C10 shown in FIG. The third surface C3 of C10 corresponds, and the sixth surface C6 of the pet food C10 shown in FIG. 1 corresponds to the sixth surface C6 of the pet food of Test Examples 1-3.

Regarding the pet food of Test Example 4, in the pet food C10 shown in FIG. 1 , only the first surface C1 and the fourth surface C4 were cut by the cutter.

<<Comparative test example 1~3>>

As the pet food of Comparative Test Example 1, a commercially available pet food for dogs was prepared. As the particles to be measured for each evaluation, ellipsoidal particles having a general shape as particles of pet food were selected.

As the pet food of Comparative Test Example 2, a commercially available pet food for cats was prepared.

As the pet food of Comparative Test Example 3, a commercially available pet food for dogs different from that of Comparative Test Example 1 was prepared.

[Table 1]

[Table 2]

The moisture content of the pet food of each example was measured with Infrared Moisture Analyzer FD-720 (manufactured by Kett Scientific Research Institute Co., Ltd.). Table 3 shows the water content of the pet food of the test example and the comparative test example.

[table 3]

<Evaluation of water absorption after immersion for 5 seconds>

The pet food to be measured for water absorption was obtained in the following procedure.

(Process 1A) One grain is selected for each pet food.

(Step 2A) Measure the mass of one grain with an electronic balance.

(Step 3A) The particles are pinched with tweezers and immersed in water.

(Step 4A) After 5 seconds had elapsed, the pellets were taken out of the water.

(Step 5A) After Step 4A, the pellets taken out were left to stand for 5 seconds, and then the pellets were rolled on a sieve (mesh 1 mm) to remove water adhering to the pellet surface.

(Step 6A) Measure the mass of one grain after immersion with an electronic scale.

The amount of water absorption is calculated as in the following formula (1). The results are shown in Tables 4-5.

5 seconds water absorption (mass %)=(mass (g) of pet food after (process 6A)-mass (g) of pet food of (process 2A))/mass (g) of pet food of (process 2A) )×100…(1)

<Evaluation of water absorption after immersion for 60 seconds>

In said process 4A, except having changed "5 seconds" to "60 seconds", the water absorption was measured similarly to <evaluation of the water absorption after immersion for 5 seconds>. The results are shown in Tables 6-7.

<Evaluation of dough volume expansion rate after dipping for 5 seconds>

The volume expansion rate of the dough when the pet food was immersed in water for 5 seconds was calculated using the following formulas (2) to (3). The results are shown in Tables 4-5.

Dough expansion volume after dipping (mm ³ ) = dough volume after dipping (mm ³ ) - dough volume before dipping (mm ³ ) - water absorption (mg)...(2)

Dough volume expansion rate (%)=(dough volume before dipping (mm ³ )+dough expansion volume after dipping (mm ³ ))/dough volume before dipping (mm ³ )...(3)

The dough volumes before and after immersion in the above formulas (2) to (3) were measured in the following procedure.

(Step 1B) One pet food to be measured is selected.

(Step 2B) Using an X-ray CT apparatus (for example, CosmoScan FX (manufactured by Rigaku Corporation)), calculate the volume of the dough before dipping.

(Step 3B) The pellets are pinched with tweezers and immersed in water.

(Step 4B) After 5 seconds had elapsed, the pellets were taken out of the water.

(Step 5B) After step 4B, the pellets taken out were left to stand for 5 seconds, and then the pellets were rolled on a sieve (mesh 1 mm) to remove water adhering to the pellet surface.

(Step 6B) Calculate the volume of the dough after dipping with an X-ray CT apparatus.

The following imaging conditions were used for the CT images in the above steps 2B and 6B.

(Conditions for capturing CT images)

Tube voltage: 90kV

Tube current: 88μA

Irradiation time: 2 minutes

Resolution: 50μm

FOV (Field of View): 25.6mm×25.6mm×25.6mm

matrix: 512×512×512

In the above steps 2B and 6B, the dough area in each CT cross-sectional image is calculated by the following procedure.

(ib) Using image analysis software (for example, Fiji), X-ray CT images are binarized (maximum entropy method). In each particle cross-section image, the background value was subtracted to calculate the dough area.

Since the CT image is measured by dividing the FOV (Field of View) into 512 equal parts, one CT cross-sectional image can be regarded as having a thickness of 50 μm. Therefore, if the dough area of one CT cross-sectional image is multiplied by the thickness of 50 μm, the dough volume of one CT cross-sectional image is obtained, and the volume of all CT cross-sectional images is added to calculate the dough of one food grain to be measured volume.

<Evaluation of Dough Volume Expansion Ratio after Dipping for 60 Seconds>

In the above-mentioned step 4B, except that "5 seconds" is changed to "60 seconds", the above-mentioned formula (2) is used in the same manner as <Evaluation of volume-based dough expansion ratio after immersion for 5 seconds> -(3) Calculate the volume expansion rate of the dough when the pet food is immersed in water for 60 seconds. The results are shown in Tables 6-7.

<Evaluation of opening volume change rate after immersion for 5 seconds>

When the pet food was immersed in water for 5 seconds, the ratio of change (open pore volume ratio) of the pet food before immersion in water to 100% of the open pore volume ratio was calculated using the following formulas (4) to (6). pore volume change rate). The results are shown in Tables 4-5.

Open cell volume (mm ³ ) = particle volume (mm ³ ) - dough volume (mm ³ )...(4)

Open pore volume ratio (%) = open pore volume (mm ³ )/particle volume (mm ³ )×100...(5)

Open pore volume change rate (%) = open pore volume rate after immersion (%) / open pore volume rate before immersion (%) × 100...(6)

The particle volume and dough volume in the above-mentioned formula (4) are subjected to the same steps and conditions as the dough volume before and after immersion measured when calculating the above-mentioned "dough volume expansion rate" (the above-mentioned steps 1B to 6B), using an X-ray CT device and Image analysis software is used to perform the measurement according to the following steps (ib) to (iiib).

(ib) Using image analysis software (for example, Fiji), X-ray CT images are binarized (maximum entropy method). In each particle cross-section image, the background value was subtracted to calculate the dough area.

(iib) In each CT cross-sectional image, use Fill holes and Dilate/Erode to process and fill the openings and subtract the background value to calculate the area of the entire particle.

(iiib) The open cell area is calculated by subtracting the area of the dough calculated in the process (ib) from the area of the entire granule calculated in the process (iib).

Under the above conditions, since the CT image is measured by dividing the FOV (Field of View) into 512 equal parts, one CT cross-sectional image can be regarded as having a thickness of 50 μm. Therefore, if the dough area, grain area, and opening area of one CT cross-sectional image are multiplied by a thickness of 50 μm, the dough volume, grain volume, and opening volume of one CT cross-sectional image are obtained by multiplying all CT cross-sectional images The volumes are added to calculate the dough volume, grain volume, and open cell volume of one food grain to be measured.

<Evaluation of opening volume change rate after immersion for 60 seconds>

In said process 4B, except having changed "5 seconds" to "60 seconds", the opening volume change rate was measured similarly to <the opening volume change rate after immersion for 5 seconds>. The results are shown in Tables 6-7.

<Evaluation of Dough Area Change Rate in the Cross Section of the Center Part of Pet Food Granules>

When the pet food was immersed in water for 5 seconds, the change rate of the dough area relative to the dough area in the cross section of the central part of the pet food pellet before immersion in water was calculated by the following formula (7) (100 area % change rate (dipping After 5 seconds, the dough area change rate of the central cross-section). The results are shown in Table 9.

After dipping for 5 seconds, the rate of change in dough area of the central cross-section (%) = Dough area of the cross-section of the central portion of the pellet after dipping (mm ² )/Dough area of the cross-section of the central portion of the pellet before dipping (mm ² )× 100…(7)

The area of the dough before and after immersion in the above formula (7) was measured in the following procedure.

(Step 1C) One pet food to be measured is selected.

(Step 2C) Using an X-ray CT apparatus (for example, CosmoScan FX (manufactured by Rigaku Corporation)), the area of the dough before dipping is calculated.

(Step 3C) The particles are pinched with tweezers and immersed in water.

(Step 4C) After 5 seconds or 60 seconds have elapsed, the pellets are taken out of the water.

(Step 5C) After step 4B, the pellets taken out were left to stand for 5 seconds, and then the pellets were rolled on a sieve (mesh 1 mm) to remove water adhering to the pellet surface.

(Step 6C) Using an X-ray CT apparatus, the area of the dough after immersion is calculated.

The following imaging conditions were used for the CT images in the above steps 2C and 6C.

(Conditions for capturing CT images)

Tube voltage: 90kV

Tube current: 88μA

Irradiation time: 2 minutes

Resolution: 50μm

FOV (Field of View): 25.6mm×25.6mm×25.6mm

matrix: 512×512×512

In the above steps 2C and 6C, the dough area in each CT cross-sectional image is calculated by the following procedure.

(ic) Using image analysis software (eg, Fiji), binarize the X-ray CT image (maximum entropy method). In each particle cross-section image, the background value was subtracted to calculate the dough area.

"The cross-section of the central part of the pet food granule" in "the change rate of the dough area of the central cross-section after immersion for 5 seconds" refers to: place the food granule, measure 512 CT images perpendicular to the plane from one direction, and start shooting The CT image of food particles is the xth image, and when the CT image of food particles is the yth image, (y-(x-1))×1/3+x～(y-(x-1))× Sections within the range of 2/3+x. Here, x<n, y<n, and x<y. Table 8 shows the above-mentioned x, the above-mentioned y, and the actually measured number of CT images of each test example and comparative example.

<Evaluation of Open Cell Area Change Rate in the Cross Section of the Center Part of Pet Food Pellets>

When the pet food is immersed in water for 5 seconds by the following formulas (8) to (10), the area ratio of open pores relative to the area ratio of open pores in the cross section of the central part of the pet food particles before immersion in water is 100 % rate of change (the rate of change in central cross-sectional opening area after immersion for 5 seconds). The results are shown in Table 9.

Open cell area (mm ² ) of the cross section of the central part of the granule = grain area (mm ² ) of the cross section of the central part of the granule - dough area (mm ² )...(8)

Opening area ratio (%) = opening area (mm ² )/particle area (mm ² )×100...(9)

After immersing for 5 seconds, the change rate of central cross-section opening area (%)=opening area rate after dipping (%)/opening area rate before dipping (%)...(10)

The particle area and the dough area in the above formula (8) are determined by the same procedures and conditions as the dough area before and after immersion measured when calculating the above-mentioned "dough area change rate of the central section after 5 seconds of immersion" (the steps 1C to 6C ), measured by the following steps (ic) to (iiiic) using an X-ray CT apparatus and image analysis software. It should be noted that, in the above formula (8), the area of the dough after immersion also includes the area of absorbed water.

(ic) Using image analysis software (eg, Fiji), binarize the X-ray CT image (maximum entropy method). In each particle cross-section image, the background value was subtracted to calculate the dough area.

(iic) In each CT cross-sectional image, use Fill holes and Dilate/Erode to process the buried openings and subtract the background value to calculate the overall area of the particles.

(iiic) The open cell area is calculated by subtracting the area of the dough calculated in the process (ic) from the area of the whole of the particles calculated in the process (iic).

The "cross-section of the central part of the pet food pellet" in the "change rate of central cross-sectional opening area after immersion for 5 seconds" and the "cross-section of the central section of the dough area after immersion for 5 seconds" in the "pet food pellet The section of the central part of the "is the same.

<Evaluation of particle density change rate after immersion of pet food for 5 seconds>

The rate of change in particle density of the pet food in water for 5 seconds (the rate of change in particle density after immersion for 5 seconds) was calculated by the following formulas (11) to (13). The results are shown in Tables 4-5.

Particle volume (L) = particle volume (mm ³ )/1000000...(11)

Particle density (g/L) = particle mass (g)/particle volume (L)...(12)

Particle density change rate (%) = particle density after impregnation (g/L) / particle density before impregnation (g/L) × 100...(13)

The particle mass in the above formula (12) is measured in the same procedure as Steps 1A to 6A in the measurement of the above-mentioned "water absorption rate".

In addition, regarding the particle volume in the above-mentioned formula (12), an X-ray CT apparatus was used through the same procedure and conditions as the particle volume before and after immersion measured when calculating the above-mentioned "opening volume change rate" (the above-mentioned steps 1B to 6B). and image analysis software, and measure the area of the entire particle (particle area) through the above steps (ib) to (iib). Under the above conditions, since the CT image is measured by dividing the FOV (Field of View) into 512 equal parts, one CT cross-sectional image can be regarded as having a thickness of 50 μm. Therefore, if the particle area of one CT cross-sectional image is multiplied by the thickness of 50 μm, it becomes the particle volume of one CT cross-sectional image, and the volumes of all the CT cross-sectional images are added to calculate the volume of one food particle to be measured. particle volume.

<Evaluation of rate of change in particle density of pet food after 60 seconds of immersion>

The rate of change in particle density of pet food in water for 60 seconds (the rate of change in particle density after immersion for 60 seconds) is the same as < Evaluation of particle density change rate after immersion of pet food for 5 seconds> Measured in the same manner. The results are shown in Tables 6-7.

[Table 4]

[table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

From the results shown in Tables 4 to 7, it was confirmed that the pet food of the test example had a higher water absorption rate than the pet food of the comparative test example, and thus absorbed more water in a short time.

In addition, it was confirmed from the results shown in Tables 4 to 7 that the pet food of the test example had a larger dough volume expansion ratio and a larger change in the open cell volume ratio (decrease in the open cell volume ratio) than the pet food of the comparative test example. Absorbs more water in a short time.

In addition, from the results shown in Tables 4 to 7, it was confirmed that the pet food of the test example absorbed more water in a short time because the particle density change rate was higher than that of the pet food of the comparative test example.

From the results shown in Table 9, it was confirmed that the pet food of the test example absorbs water and swells the particles compared with the pet food of the comparative test example.

Fig. 6 is a CT image obtained by measuring the cross section of the central part of the particle perpendicular to the plane from the first direction in Fig. 1 of the pet food of Test Example 1 before immersion in water. Fig. 7 is a CT image obtained by measuring the cross section of the central portion of the particles perpendicular to the plane from the first direction in Fig. 1 of the pet food of Test Example 1 after being immersed in water for 5 seconds. Fig. 8 is a CT image obtained by measuring the cross-section of the central part of the particles perpendicular to the plane from one direction of the pet food for dogs (commercially available) of Comparative Test Example 1 before immersion in water. 9 is a CT image obtained by measuring the cross section of the central part of the grain perpendicular to the plane from one direction of the pet food for dogs (commercially available) of Comparative Test Example 1 after being immersed in water for 5 seconds. Fig. 10 is a CT image obtained by measuring the cross section of the central portion of the particles perpendicular to the plane from one direction of the pet food for cats (commercially available) of Comparative Test Example 2 before immersion in water. 11 is a CT image obtained by measuring the cross section of the central part of the particles perpendicular to the plane from one direction of the pet food for cats (commercially available) of Comparative Test Example 2 after being immersed in water for 5 seconds.

In Fig. 6, Fig. 8 and Fig. 10, the white part is the dough part, and the black part is the hole part. In addition, in FIG. 7 , FIG. 9 and FIG. 11 , the white part is the dough part and the water-absorbing part, and the black part is the hole part.

As shown in FIGS. 6 to 11 , it was confirmed that the pet food of Test Example 1 absorbs water and swells the particles compared with the pet foods of Comparative Test Examples 1 and 2 .

<Evaluation using a liquid with a viscosity of 1.5dPa·s>

For the pet food of Test Example 2 and the pet food of Comparative Test Example 2, except for using commercially available soup-type pet food adjusted to a viscosity of 1.5 dPa·s and a temperature of 20° C. Evaluation of water absorption after 5 seconds>, <Evaluation of water absorption after 60 seconds of immersion>, <Evaluation of dough swelling rate based on volume after 5 seconds of immersion>, <Based on volume after 60 seconds of immersion Evaluation of dough expansion rate>, <open cell volume change rate after 5-second immersion>, <open-cell volume change rate after 60-second immersion>, <particle density change after 5-second immersion of pet food Rate> and <evaluation of particle density change rate after immersion of pet food for 60 seconds> were the same evaluations. The results are shown in Tables 10-13.

[Table 10]

[Table 11]

[Table 12]

[Table 13]

From the results shown in Tables 10 to 13, it was confirmed that the pet food of the test example had a higher water absorption rate than the pet food of the comparative test example, and thus absorbed more soup-type pet food in a short time.

In addition, it was confirmed from the results shown in Tables 10 to 13 that the pet food of the test example had a larger dough volume expansion ratio and a larger change in the open cell volume ratio (decrease in the open cell volume ratio) than the pet food of the comparative test example. Absorb more soup pet food in a short time.

In addition, from the results shown in Tables 10 to 13, it was confirmed that the pet food of the test example absorbed more soup-type pet food in a short time because the particle density change rate was higher than that of the pet food of the comparative test example.

<Evaluation of Hardness>

For the pet food to be evaluated for hardness, pet food granules before immersion in the pet food to be measured obtained in the above <Evaluation of Water Absorption> were used, and the pet food was prepared in water or adjusted to have a viscosity of 1.5 dPa·s and a temperature of 20°C. The evaluation was performed on pet food pellets dipped in a commercially available soup-type pet food for 5 seconds.

For the pet foods of Test Examples 1 to 4, the surface with the lowest surface area ratio of the surface obtained by projecting the pet food in one direction (the surface in the third direction in FIG. C6) Determination of hardness.

For the pet foods of Comparative Test Examples 2 and 3, since there is no surface with a large difference in porosity on the surface of the pellets, the hardness was measured by placing them so that the major axis was parallel to the tray.

The value of the hardness of the pet food of each example was obtained by the following measuring method.

Using a compression tester (texture analyzer, model: EZ-SX, manufactured by Shimadzu Corporation), the breaking force when the pet food was compressed at a constant compression speed was measured.

Specifically, one pet food to be measured was placed on a tray, and the test force was measured while pressing the plunger vertically at a constant speed from directly above. The peak value (maximum value) of the test force is read as the value of the breaking force. The measurement was repeated for 10 pet foods, and the average value was calculated.

The value of the breaking force (unit: kgw) measured by the above-mentioned compression testing machine was multiplied by 9.8 to convert the unit into Newton (N).

Measurement conditions are as follows.

Plunger: width 10mm, length 20mm, front end 1mm thick, wedge-shaped plunger

Platform: flat tray with a diameter of 100mm

Compression speed: 60mm/min

The lowest point of the plunger: Set to press 70% to 90% of the thickness (height) of the pet food

Measuring temperature: 25°C

The results are shown in Table 14.

[Table 14]

From the evaluation of the above-mentioned hardness, it was confirmed that the pet food of the test example became softer in a shorter time than the pet food of the comparative test example.

<<Reference Example 1, Test Example 5, Comparative Test Example 4~5>>

The pet food of Reference Example 1 to be evaluated for palatability was produced by the above-mentioned production method in accordance with the formulation shown in Table 1 in the same manner as in Test Examples 1 to 4. In addition, the water content of the pet food of Example 1 obtained by the above-mentioned "loss on drying method" was 8.4%.

The pet food obtained by immersing the pet food of Reference Example 1 in water for 5 seconds was used as the pet food of Test Example 5.

The pet food obtained by immersing the pet food of Comparative Test Example 1 in water for 5 seconds was used as the pet food of Comparative Test Example 4.

A commercially available soft food was used as the pet food of Comparative Test Example 5.

<Evaluation of palatability>

For the pet food P of Test Example 5 and each of the pet foods Q of Comparative Test Example 4 or 5, the palatability was evaluated by comparing food intake. The test was carried out for 2 days with 12 dogs as monitors.

On the first day, one of the pet foods P and Q was given to a dog at the same time from the left and the other from the right at a predetermined feeding amount, and the time point or 30 minutes after the dog finished eating one of them was measured. The amount of pet food consumed by the dog.

The ratio of the intake of pet food Q to the intake of pet food P was calculated as a percentage (P: Q, P+Q=100%) with respect to the mass of the total pet food eaten by the dog on the first day. The resulting percentages were averaged based on the number of dogs monitored as Day 1 results.

On the second day, contrary to the first day, one of the pet foods P and Q was administered from the right and the other from the left. The same amount of food as that on the first day was given to one dog, and the amount of pet food eaten by the dog was measured at the time point when the dog finished eating one of them or 30 minutes later. The results of the second day were obtained by the same calculation method as the first day.

Finally, the results of the first day and the second day are averaged to obtain the ratio "P:Q" of the food intake of pet food P:pet food Q as a final result. The higher the value of P or Q, the more likely the monitored dog is to eat. If the value of P exceeds 50%, it means that palatability is improved compared with pet food Q.

As a result of the palatability test, the pet food of Test Example 5 and the pet food of Comparative Test Example 4 were P:Q=62:38, and the pet food of Test Example 5 was evaluated to have higher palatability than the pet food of Comparative Test Example 4. . This is presumed to be because the pet food of Test Example 5 absorbed more water than the pet food of Comparative Test Example 4, so palatability improved.

In addition, the pet food of Test Example 5 and the pet food of Comparative Test Example 5 were P:Q=53:47, and the pet food of Test Example 5 was evaluated to have palatability equal to or higher than that of commercially available soft food. Therefore, it can be confirmed that the pet food of Test Example 5 has the advantages of dry pet food such as preservation and handling properties, and that when immersed in water, the palatability is improved to be equal to or more than that of soft food.

From the above, it was confirmed that the pet food to which the examples of the present invention were applied had an excellent water absorption rate even in a short-time immersion, and that palatability was improved when immersing in water.

The preferred examples of the present invention have been described above, but the present invention is not limited to these examples. Structural additions, omissions, substitutions, and other changes can be made without departing from the gist of the present invention. The present invention is not limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims (13)

1. A pet food having a moisture content of 15% or less, wherein when immersed in water for 5 seconds, 30% or more by mass of water is absorbed relative to 100% by mass of the pet food.

2. The pet food of claim 1, wherein the hardness of the particles of the pet food immersed in the water for 5 seconds is 50.0N or less.

3. The pet food according to claim 1 or 2, wherein 50 mass% or more of the water is absorbed with respect to 100 mass% of the pet food when immersed in the water for 60 seconds.

4. A pet food product as claimed in any of claims 1 to 3 wherein the dough expands by more than 5% by volume relative to 100% by volume of the dough of the pet food product prior to immersion in the water when immersed in the water for 5 seconds.

5. The pet food of any one of claims 1-4, wherein upon immersion in the water for 60 seconds, the dough expands by 5% or more by volume relative to 100% by volume of the dough of the pet food prior to immersion in the water.

6. The pet food of any one of claims 1-5, wherein the open cell volume fraction is 85% or less relative to 100% of the open cell volume fraction of the pet food prior to immersion in the water when immersed in the water for 5 seconds.

7. The pet food of any one of claims 1-6, wherein the open cell volume ratio is 80% or less relative to 100% of the open cell volume ratio of the pet food prior to immersion in the water when immersed in the water for 60 seconds.

8. The pet food of any one of claims 1-7, wherein upon immersion in the water for 5 seconds, the dough area increases by 45 area% or more relative to 100 area% in cross section of the central portion of the particles of pet food prior to immersion in the water.

9. The pet food according to any one of claims 1 to 8, wherein when immersed in the water for 5 seconds, the open area ratio is 80% or less relative to 100% of the open area ratio in the cross section of the central portion of the particles of the pet food before immersion in the water.

10. The pet food of any one of claims 1-9, wherein upon immersion in the water for 5 seconds, the particle density increases by greater than 10% relative to 100% of the particle density of the pet food prior to immersion in the water.

11. The pet food of any one of claims 1-10, wherein upon immersion in the water for 60 seconds, the particle density is increased by 15% or more relative to 100% of the particle density of the pet food prior to immersion in the water.

12. A pet food having a moisture content of 15% or less, wherein when immersed in a liquid having a viscosity of 1.5 dPa.s for 5 seconds, 30% or more by mass of the liquid is absorbed relative to 100% by mass of the pet food.

13. The pet food product of claim 12, wherein the hardness of the particles of the pet food product immersed in the liquid for 5 seconds is 50.0N or less.