Curd crushing tool, curd crushing device, method for producing fermented milk and fermented milk

Abstract

To provide a curd crushing implement that enables manufacture of fermented milk with a smooth texture and maintained viscosity and that is less likely to cause clogging.SOLUTION: A curd crushing implement 5, which is arranged in piping for circulating fermented milk including a curd, comprises a plate part 51 that is provided with a plurality of holes 52 penetrating in a circulation direction of the fermented milk. A cross-sectional area of each of the holes 52 is in the range of 0.5-7.5 mm2, and the total of the cross-sectional areas of the plurality of holes 52 is in the range of 20-40 mm2.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a curd crushing tool and a curd crushing device for crushing curds contained in fermented milk. The present invention also relates to a method for producing fermented milk, which includes a crushing step of crushing curds contained in fermented milk, and the fermented milk produced by the production method. [Background technology]

[0002] In the intestines of living organisms, a complex microbial environment is formed in which many types of bacteria maintain a balance between proliferation and death, and this environment is called the intestinal microbiota or intestinal flora. This intestinal microbiota can have important physiological effects that promote human health, and it is known that some types of bacteria can improve immune function and reduce visceral fat. For this reason, interest in intestinal flora has increased in general in recent years, and the demand for fermented milk has increased.

[0003] As specified in the Ministerial Ordinance on Milk, etc., fermented milk refers to milk or milk containing an equivalent or greater amount of non-fat milk solids fermented with lactic acid bacteria or yeast. Fermented milk is classified into post-fermented fermented milk and pre-fermented fermented milk according to the production method. Pre-fermented fermented milk is filled into containers after fermentation, and examples of such products include drink yogurt and yogurt with fruit. Post-fermented fermented milk is fermented after filling into containers, and examples of such products include plain yogurt and hard yogurt.

[0004] As a method for producing pre-fermented fermented milk, a crushing step is known in which the curds contained in the fermented milk are crushed after the fermentation step in order to make the fermented milk have a smooth texture when eaten. However, crushing the curds makes the fermented milk have a smooth texture, but it also reduces the viscosity of the fermented milk, so there is a need for a method for maintaining the viscosity of the fermented milk at a required level while performing the crushing step. For example, Patent Document 1 discloses a method for reducing the number of curd particles without particularly decreasing the viscosity by pushing out and crushing the fermented milk after fermentation through openings equivalent to 325 to 1300 mesh (JIS sieve standard) in a crushing step. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2006 / 057266 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the method described in Patent Document 1, fermented milk passes through a curd crusher having fine openings of 325 to 1300 mesh. For example, the opening of a 325 mesh is 0.043 mm. Therefore, depending on the conditions of the fermented milk, the opening of the curd crusher may become clogged.

[0007] The present invention aims to provide a curd crusher capable of producing fermented milk having a smooth texture and a maintained viscosity and having a low possibility of clogging, and a curd crushing device using the curd crusher. The present invention also aims to provide a method for producing fermented milk capable of producing fermented milk having a smooth texture and a maintained viscosity in a less time-consuming manner, and fermented milk produced by the method. [Means for solving the problem]

[0008] The curd crushing device of the present invention is a curd crushing device to be placed in a pipe through which fermented milk containing curd flows, and the device comprises a plate portion having a plurality of holes penetrating in the flow direction of the fermented milk, and each of the plurality of holes has a cross-sectional area of ​​0.5 to 7.5 mm. 2 The total cross-sectional area of ​​the plurality of holes is 20 to 40 mm 2 It is.

[0009] In the curd crusher of the present invention, the balance between the total cross-sectional area of ​​the holes and the cross-sectional area of ​​each hole is adjusted, so that the change in the flow rate of the fermented milk passing through each hole of the plate part and the contact amount between the curds and the plate part are adjusted, and the curds are sufficiently crushed without being excessively crushed. This produces fermented milk with a smooth texture and maintained viscosity. In addition, in the curd crusher of the present invention, the size of each hole through which the fermented milk flows is sufficiently larger than the opening of a conventional mesh, so that the fermented milk is less likely to become clogged. The pipe in which the card crusher of the present invention is placed may be any pipe commonly used in the production of fermented milk, such as 1.0S stainless steel sanitary pipe (JIS G 3447). The flow rate of the fermented milk flowing through this pipe may be approximately the same as that during filling of the fermented milk, such as 550 L / h.

[0010] In the card crusher of the present invention, the cross-sectional area of ​​each of the plurality of holes is 0.8 to 7.1 mm 2 The total cross-sectional area of ​​the plurality of holes is 27.5 to 35.0 mm 2 It is preferable that:

[0011] In the card crusher of the present invention, the cross-sectional area of ​​each of the plurality of holes is 3.1 to 7.1 mm 2 It is even more preferable that:

[0012] In the card crusher of the present invention, it is preferable that the cross-sectional shape of the hole is circular. With this configuration, it is possible to apply a crushing force uniformly to the curds in the fermented milk ejected from each hole. Also, since no corners are formed in the holes, it is possible to prevent the fermented milk from sticking.

[0013] The card crushing device of the present invention includes the card crushing tool described above and the piping in which the card crushing tool is disposed. According to the curd crushing device of the present invention, like the above-mentioned curd crushing tool of the present invention, it is possible to produce fermented milk having a smooth texture and maintaining viscosity.

[0014] It is preferable that the card crushing device of the present invention further includes an annular sealing member sandwiched between the first joint portion and the second joint portion of the piping and having an inner diameter larger than an inner diameter of the piping, and the plate portion is disposed radially inward of the annular sealing member. In this configuration, the card crusher can be removed from the piping, and the card crusher can be easily replaced. For example, multiple types of card crushers with different total cross-sectional areas of the holes or different cross-sectional areas of the holes may be prepared, and the type of card crusher installed in the card crushing device may be changed depending on the type of fermented milk to be produced.

[0015] The method for producing fermented milk of the present invention includes a crushing step of passing fermented milk obtained by fermenting a fermented milk raw material through a pipe provided with a curd crusher, and crushing the curds contained in the fermented milk. The curd crusher has a plate portion provided with a plurality of holes penetrating in the flow direction of the fermented milk, and each of the plurality of holes has a cross-sectional area of ​​0.5 to 7.5 mm. 2 In the crushing step, the fermented milk passes through the curd crusher at a linear velocity of 3.0 to 6.0 m / s.

[0016] The method for producing fermented milk of the present invention includes a crushing step of passing fermented milk obtained by fermenting a fermented milk raw material through a pipe provided with a curd crusher, and crushing the curds contained in the fermented milk. The curd crusher has a plate portion provided with a plurality of holes penetrating in the flow direction of the fermented milk, and each of the plurality of holes has a cross-sectional area of ​​0.5 to 7.5 mm. 2 The total cross-sectional area of ​​the plurality of holes is 20 to 40 mm 2 It is.

[0017] According to any of the manufacturing methods of the present invention, as with the above-mentioned curd crusher of the present invention, the curds are sufficiently crushed without being excessively crushed, so that it is possible to produce fermented milk having a smooth texture and maintaining viscosity. Furthermore, the manufacturing method of the present invention makes it easier to manage the curd crusher compared to conventional manufacturing methods, so that it is possible to reduce the labor required for manufacturing.

[0018] The fermented milk of the present invention is fermented milk produced by the above-mentioned production method, and has a viscosity of 7500 to 9500 cP (measurement temperature: 10°C), the volume ratio of the curd having a particle diameter of 200 μm or more to the total particles of the curd is less than 10%, and the particle diameter of the curd is in the range of less than 700 μm. Such fermented milk has a smooth texture and maintains its viscosity, which makes it possible to improve the texture without the need for additives while maintaining manufacturing suitability, such as filling. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic diagram showing a card crushing device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a front view showing the card crusher according to the embodiment of the present invention. [Diagram 3] FIG. 4 is a cross-sectional view showing a schematic installation state of the card crusher according to the embodiment. [Figure 4] FIG. 13 is a front view showing a modified example of the card crusher according to the embodiment. [Diagram 5] 2 is a graph showing the results of viscosity measurements for Examples 1 to 6 and Comparative Examples 1 to 7. [Figure 6] 1 is a graph showing the measurement results of particle size distribution for Examples 1 and 4 and Comparative Examples 1 and 2. [Figure 7] 7 is a graph showing an enlarged portion of FIG. 6. [Figure 8] Graph showing the measurement results of particle size distribution for Examples 2 and 5 and Comparative Examples 3 and 4. [Figure 9] 9 is a graph showing an enlarged view of a part of FIG. 8. [Figure 10] 1 is a graph showing the measurement results of particle size distribution for Examples 3 and 6 and Comparative Examples 5 to 7. [Figure 11] 11 is a graph showing an enlarged portion of FIG. 10 . [Figure 12] 1 is a graph showing the measurement results of the card remaining ratio for Examples 1 to 6 and Comparative Examples 1 to 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment relates to the production of pre-fermented fermented milk in which a fermented milk raw material is fermented and then crushed.

[0021] [Card shredding device and card shredding tool] FIG. 1 is a schematic diagram showing a card crushing device 1 according to one embodiment of the present invention. The curd crushing device 1 of this embodiment crushes the curds contained in the fermented milk after fermentation to produce fermented milk with a smooth texture. As shown in Fig. 1, the curd crushing device 1 includes a hopper 2 for feeding the fermented fermented milk, a pump 3 for delivering the fed fermented milk, a pipe 4 through which the fermented milk fed to the pump 3 flows, a curd crushing tool 5 for crushing the curds in the fermented milk flowing through the pipe 4, and a discharge section 6 for discharging the fermented milk with the crushed curds. The curd crushing device 1 may also include a flow meter 71 and a pressure meter 72 between the pump 3 and the curd crushing tool 5 to measure the crushing force of the curd crushing tool 5. The pipe 4 may be any pipe generally used in the production of fermented milk, for example, stainless steel sanitary pipe (JIS G 3447) 1.0S (inner diameter 23.0 mm).

[0022] As shown in Fig. 2, the card crusher 5 of this embodiment includes a disk-shaped plate portion 51. The plate portion 51 is provided with a plurality of holes 52 penetrating the plate portion 51 in the thickness direction.

[0023] The number, size and shape of the holes 52 provided in the plate portion 51 are not limited to those shown in FIG. 2, and the total cross-sectional area of ​​the holes 52 is not limited to 20 to 40 mm 2 and the cross-sectional area of ​​each of the holes 52 is 0.5 to 7.5 mm 2 The range may be changed arbitrarily as long as it is within the above range. For example, the card crusher 5 shown in Fig. 2 corresponds to Example 2 described later. In this card crusher 5, the cross-sectional shape of the hole 52 is circular, and the cross-sectional area of ​​the hole 52 is 3.1 mm2 The total cross-sectional area of ​​the holes 52 is 27.5 mm 2 It is.

[0024] The total cross-sectional area of ​​the holes 52 of the card crusher 5 is 27.5 to 35.0 mm 2 and the cross-sectional area of ​​each of the holes 52 is 0.8 to 7.1 mm 2 Furthermore, it is preferable that the cross-sectional area of ​​each of the holes 52 of the card crusher 5 is 3.1 to 7.1 mm. 2 It is more preferable that:

[0025] Although not particularly limited, it is preferable that all of the holes 52 in the plate portion 51 are the same size. Furthermore, although not particularly limited, the arrangement of the holes 52 in the plate portion 51 is preferably such that the holes 52 are spaced apart from one another at equal intervals. Furthermore, the thickness dimension of plate portion 51, i.e., the length of hole 52 penetrating plate portion 51, is not particularly limited, but is preferably 2.0 to 30.0 mm, more preferably 2.0 to 20.0 mm, and most preferably 2.0 to 5.0 mm.

[0026] Such a card crusher 5 can be installed between the joints 41 and 42 of the pipe 4 as shown in FIG. Specifically, the joints 41, 42 (first joint and second joint) of the pipe 4 are, for example, ferrule joints and have flanges 411, 421. Between the flanges 411, 421, an annular seal member 43 such as a gasket is sandwiched. Here, the size standard (e.g., 1.5S) of the annular seal member 43 is selected to be larger than the size standard (e.g., 1.0S) of the pipe 4, and the inner diameter (e.g., 35.7 mm) of the annular seal member 43 is larger than the inner diameter (e.g., 23.0 mm) of the pipe 4. The card crusher 5 is disposed radially inside the annular seal member 43 and is installed so as to be sandwiched between the flanges 411, 421. In the card crusher 5 thus installed, the thickness direction of the plate portion 51 is the direction parallel to the flow direction F of the fermented milk.

[0027] [Production method of fermented milk] The method for producing fermented milk in this embodiment includes a crushing step of crushing curds contained in fermented milk obtained by fermenting a fermented milk raw material using the curd crushing device 1 described above.

[0028] The milk and dairy products used as raw materials for fermented milk fall under the category of "milk" and "dairy products" in the Ministerial Ordinance on the Compositional Standards of Milk and Dairy Products (Ministry of Health and Welfare No. 52, December 27, 1951). In other words, "milk" refers to raw milk, cow's milk, special cow's milk, raw goat's milk, pasteurized goat's milk, raw sheep's milk, adjusted milk, low-fat milk, non-fat milk and processed milk, while "dairy products" refers to cream, butter, butter oil, cheese, concentrated whey, ice cream, concentrated milk, skim concentrated milk, unsweetened condensed milk, unsweetened condensed skim milk, sweetened condensed milk, sweetened condensed skim milk, whole milk powder, skim milk powder, cream powder, whey powder, protein concentrated whey powder, buttermilk powder, sweetened milk powder, modified milk powder, fermented milk, lactic acid bacteria drinks (limited to those containing 3.0% or more non-fat milk solids) and milk drinks. Such milk or dairy products can be used as the raw material for fermented milk either as is or after adjustment such as dilution. This raw material can be fermented with the addition of lactic acid bacteria, bifidobacteria, yeast, etc. to become fermented milk containing curds (coagulated material), and the fermented milk is fed into the hopper 2 of the curd crushing device 1.

[0029] In the crushing step of this embodiment, first, fermented milk is continuously fed to the pipe 4 at a predetermined pressure by the pump 3. The flow rate of the fermented milk flowing through the pipe 4 may be approximately the same as that when the fermented milk is filled, for example, 550 L / h. At such a flow rate, the fermented milk passes through each hole 52 at a linear speed of 3.0 to 6.0 m / s due to the relationship with the flow path cross-sectional area of ​​the fermented milk in the curd crushing device 5, i.e., the total cross-sectional area of ​​the holes 52 in the plate portion 51. At this time, the curds are crushed due to factors such as contact between the curds in the fermented milk and the plate portion 51 and a change in flow rate when the fermented milk passes through the holes 52. The fermented milk crushed by the curd crusher 5 may be discharged from the discharge part 6 and filled into a container or the like.

[0030] The fermented milk produced by the above-mentioned crushing step has a viscosity of 7500 to 9500 cP (measurement temperature: 10° C.), a curd residue of less than 10%, and a maximum particle size of the curd of less than 700 μm. The viscosity, curd residue and maximum particle size of the curd can be defined as values ​​measured by the methods used in the examples described later.

[0031] [Effects of the embodiment] According to this embodiment, the balance between the total cross-sectional area of ​​the holes 52 in the plate portion 51 of the curd crusher 5 and the cross-sectional area of ​​each hole 52 is adjusted, so that the factors that crush the curds are adjusted and the curds are sufficiently crushed without being excessively crushed. This produces fermented milk that has a smooth texture and maintains its viscosity. In addition, in the card crusher 5 of the present embodiment, the size of each hole 52 through which the fermented milk flows is sufficiently larger than the opening of a conventional mesh, so that the possibility of the fermented milk clogging the holes is low. This reduces the effort required for managing the card crusher 5.

[0032] In the card crusher 5 of the present embodiment, the cross-sectional shape of the holes 52 is circular, so that a crushing force can be applied uniformly to the curds in the fermented milk ejected from each hole 52. In addition, since no corners are formed in the holes 52, adhesion of the fermented milk can be suppressed.

[0033] In the card crushing device 1 of this embodiment, the card crushing tool 5 can be removed from the pipes 4, and the card crushing tool 5 can be easily replaced. For example, multiple types of card crushing tools 5 having different total cross-sectional areas of the holes 52 or different cross-sectional areas of the individual holes 52 may be prepared, and the type of card crushing tool 5 installed in the card crushing device 1 may be changed depending on the type of fermented milk to be produced.

[0034] In the method for producing fermented milk according to the present embodiment, fermented milk having a smooth texture and maintaining viscosity is produced by carrying out a crushing step using the above-mentioned curd crusher 5. In addition, as described above, since there is no need to take time and effort to manage the curd crusher 5, fermented milk can be produced by a less time-consuming method. Furthermore, the fermented milk produced in this embodiment is defined as fermented milk having a viscosity of 7500 to 9500 cP (measurement temperature: 10° C.), a curd residue of less than 10%, and a maximum particle size of the curd of less than 700 μm. Such fermented milk can maintain production suitability such as filling while improving the texture without requiring additives.

[0035] [Variations] The present invention is not limited to the above-described embodiment, and includes modifications and improvements within the scope of the present invention that can achieve the object of the present invention.

[0036] In the card crusher 5 of the above embodiment, the cross-sectional shape of the holes 52 is circular, but the present invention is not limited to this, and the shape may be a triangle, square, rectangle, polygon with 5 or more sides or a regular polygon, ellipse, or the like.

[0037] The card crusher 5 of the above embodiment may be configured with the plate portion 51 alone, or may be configured in combination with other members. For example, as shown in Fig. 4, a card crusher 5A according to a modified example includes a disk-shaped plate portion 51 and a pipe portion 53 into which the plate portion 51 is fitted. In this modified example, the plate portion 51 is arranged such that the outer periphery of the plate portion 51 fits into the inner periphery of the pipe portion 53. The pipe portion 53 has joint portions 531, 532 provided on both ends thereof. The joint portions 531, 532 are, for example, ferrule joints, and are each connected to a joint portion of the pipe 4. In this manner, the card crusher 5A is installed. Additionally, the card crusher 5 is not limited to the configuration described in the above embodiment, and may be installed in the pipe 4 in any manner.

[0038] The curd crusher 5 of the embodiment is not limited to being installed in the curd crushing device 1 as described above, but may be installed at least in a pipe through which fermented milk containing curds flows.

[0039] In the crushing step of the above embodiment, the flow rate of the fermented milk flowing through the pipe 4 is 550 L / h, but the present invention is not limited to this. For example, the flow rate may be adjusted so that the fermented milk passes through the card crusher 5 at a linear velocity of 3.0 to 6.0 m / s.

[0040] In the above embodiment, the condition of the card crusher 5 is that each of the multiple holes 52 has a cross-sectional area of ​​0.5 to 7.5 mm 2 The total cross-sectional area of ​​the holes 52 is 20 to 40 mm 2 It lists the following as reasons. However, when using piping or flow rates other than those of general use, the cross-sectional area of ​​each of the multiple holes 52 must be 0.5 to 7.5 mm 2 The curd crusher 5 may be used such that the linear velocity of the fermented milk passing through the curd crusher is 3.0 to 6.0 m / s, and the total cross-sectional area of ​​the multiple holes 52 may be outside the above range. EXAMPLES

[0041] The present invention will be described in more detail below with reference to examples and comparative examples. In Examples 1 to 6, the curds of fermented milk were crushed using the above-mentioned curd crushing device 1 (see FIG. 1). On the other hand, in Comparative Examples 1 to 7, the holes 52 (see FIG. 2) of the card crushing tool 5 of the above-mentioned curd crushing device 1 were changed to a range different from that described in the above embodiment, and the curds of fermented milk were crushed.

[0042] In Examples 1 to 6 and Comparative Examples 1 to 7, the flow rate of the fermented milk flowing through the pipe 4 was 550 L / h. The fermented milk used had a non-fat milk solid content of 9.5% and a milk fat content of 3.0%. In the explanation of Comparative Examples 1 to 7, the symbols given to the elements in the above embodiment are used as in the explanation of Examples 1 to 6. Furthermore, the numerical values ​​of the cross-sectional area and the like are calculated with the significant digits rounded to one decimal place.

[0043] The conditions in Examples 1 to 6 and Comparative Examples 1 to 7 are summarized in Table 1 below. In Table 1, "hole shape" refers to the cross-sectional shape of the hole 52 in the plate portion 51 of the card crusher 5. "hole diameter" refers to the diameter of the hole 52 when the cross-sectional shape of the hole 52 is circular, and "short side dimension" refers to the short side dimension of the hole 52 when the cross-sectional shape of the hole 52 is rectangular. "Cross-sectional area of ​​hole" refers to the cross-sectional area of ​​one hole 52, and "total cross-sectional area of ​​hole" refers to the total cross-sectional area of ​​the holes 52 in the plate portion 51. "Linear speed" refers to the flow speed when the fermented milk passes through the hole 52 of the card crusher 5, and is a value calculated by the following formula (1). Linear velocity [m / s] = Volumetric flow rate [m 3 / s] / cross-sectional area [m 2 ] ...Equation (1) In the above formula (1), the volumetric flow rate [m 3 / s] is calculated based on the flow rate of fermented milk flowing through the pipe 4 (550 L / h), and the cross-sectional area [m 2 ] is the total cross-sectional area [mm 2 ] was calculated based on the above. [Table 1]

[0044] In addition, in Table 1 above, in comparative examples 1, 3, and 5, the values ​​for "cross-sectional area of ​​hole" and "total cross-sectional area of ​​hole" are the same, which means that the number of holes 52 in the plate portion 51 is one.

[0045] [Evaluation method] For the fermented milk obtained in Examples 1 to 6 and Comparative Examples 1 to 7, the viscosity of the fermented milk, the particle size distribution of the curd particles contained in the fermented milk, and the proportion of residual curd were measured. Furthermore, for each of the card crushers 5 of Examples 1 to 6 and Comparative Examples 1 to 7, the presence or absence of clogging after crushing the cards was confirmed. In addition, the fermented milk obtained in Examples 1 to 6 and Comparative Examples 1 to 7 was subjected to a sensory quality evaluation test (sensory evaluation).

[0046] (viscosity) The viscosity of the fermented milk was measured using a BL type viscometer (TVB-10, Toki Sangyo Co., Ltd.) with rotor No. 4 at a rotation speed of 30 rpm and a sample temperature of 10° C. The apparent viscosity was measured 30 seconds after the start of measurement. The reduction rate of the apparent viscosity before and after passing through the crushing section was calculated as 100-(η / η0)×100, where η0 is the viscosity before crushing and η is the viscosity after crushing.

[0047] (particle size distribution) The particle size distribution of the curd particles was measured by the laser diffraction / scattering method using a particle size distribution meter (Microtrac MT3300EX-II, Nikkiso Co., Ltd.) The measurement was performed using deionized exchanged water as the solvent, with the particle refractive index set to 1.456 and the solvent refractive index set to 1.333.

[0048] (Card remaining percentage) The curd remaining ratio is the volume ratio of curd particles with a certain size or larger to the total particles of the curd. To measure this curd remaining ratio, the sample was photographed under a microscope, and the size of each curd particle contained in the sample was calculated using image analysis. The volume ratio of curd particles with a particle diameter of 200 μm or more to the total particles of the curd was calculated as the "curd remaining ratio."

[0049] (Sensory evaluation) In the sensory evaluation, the filling property and smoothness were evaluated. The filling property was adopted as an item related to the viscosity of the fermented milk. In assessing the filling ability, a state in which the container could be filled continuously from the discharge portion 6 of the card crushing device 1 without dripping was marked as ◯, a state in which intermittent dripping occurred was marked as △, and a state in which there was constant dripping was marked as ×. In the evaluation of smoothness, a state in which there was no feeling or powdery texture remaining on the tongue when eaten was rated as ◯, a state in which there was a slight feeling of the texture remaining on the tongue was △, and a state in which there was a powdery texture remaining on the tongue was rated as ×.

[0050] [result] The measurement results and the sensory evaluation results for Examples 1 to 6 and Comparative Examples 1 to 7 are shown in Table 2 below. [Table 2]

[0051] (Viscosity measurement results) The viscosity measurement results (see Table 2 above) for Examples 1 to 6 and Comparative Examples 1 to 7 were graphed (see FIG. 5). In the graph of FIG. 5, the horizontal axis represents the diameter or short side dimension of the hole 52, and the vertical axis represents the viscosity [cP]. In FIG. 5, the types of data points are classified based on the total cross-sectional area of ​​the hole 52 and the shape of the hole 52. 5, the viscosity increased as the diameter or short side dimension of the holes 52 increased. In addition, when the diameter of the holes 52 was constant, the viscosity increased as the number of the holes 52 increased, that is, the total cross-sectional area of ​​the holes 52 increased (Examples 1 to 6, Comparative Examples 2, 4, and 6). Moreover, Examples 1 to 6 and Comparative Examples 1, 3 to 4, 6, and 7 had a viscosity in the range of 7500 to 9500 cP, while Comparative Examples 2 and 5 were outside this range.

[0052] (Particle size distribution measurement results) The measurement results of particle size distribution for Examples 1 to 6 and Comparative Examples 1 to 7 are shown in Figures 6 to 11. In each graph of Figures 6 to 11, the horizontal axis represents the particle size [μm] of the curd particles, and the vertical axis represents the frequency [%]. Specifically, FIG. 6 shows the measurement results of Examples 1 and 4 and Comparative Examples 1 and 2 in which the diameter or short side dimension of hole 52 is 1.0 mm, and FIG. 7 is an enlarged view of a portion of the graph in FIG. 6 (the portion surrounded by the dotted line). FIG. 8 shows the measurement results for Examples 2 and 5 and Comparative Examples 3 and 4 in which the diameter or short side dimension of hole 52 is 2.0 mm, and FIG. 9 is an enlarged view of a portion of the graph in FIG. 8 (the portion surrounded by the dotted line). FIG. 10 shows the measurement results for Examples 3 and 6 and Comparative Examples 5 and 6 in which the diameter or short side dimension of hole 52 is 3.0 mm, as well as the measurement results for Comparative Example 7, and FIG. 11 shows an enlarged view of a portion of the graph in FIG. 10 (the portion surrounded by the dotted line).

[0053] Furthermore, for Examples 1 to 6 and Comparative Examples 1 to 7, the maximum particle sizes appearing in the particle size distribution were confirmed based on the graphs of Figures 6 to 11, and were summarized in the above Table 2. As shown in the above Table 2, in Examples 1 to 6 and Comparative Examples 1, 3, 4, and 5, the maximum particle sizes were less than 700 μm, and in Comparative Examples 2, 4, and 7, the maximum particle sizes were 700 μm or more.

[0054] (Measurement results of remaining card percentage) The measurement results of the card remaining ratio (see Table 2 above) for Examples 1 to 6 and Comparative Examples 1 to 7 were graphed (see FIG. 12). In the graph of FIG. 12, the horizontal axis represents the diameter or short side dimension of hole 52, and the vertical axis represents the card remaining ratio [%]. In FIG. 11, the types of data points are distinguished based on the total cross-sectional area of ​​hole 52 and the shape of hole 52. 11, the larger the diameter or short side dimension of hole 52, the higher the percentage of remaining cards. In addition, when the diameter of holes 52 is the same, the more the number of holes 52 is, that is, the larger the total cross-sectional area of ​​holes 52 is, the higher the percentage of remaining cards is (Examples 1 to 6, Comparative Examples 2, 4, and 6). Moreover, in Examples 1 to 6 and Comparative Examples 5 to 6, the card remaining ratio was less than 10%, while in Comparative Examples 1 to 4 and 7, the card remaining ratio was 10% or more.

[0055] (Clogged or not) In Examples 1 to 6 and Comparative Examples 1 to 7, clogging of the holes 52 of the card crusher 5 with the fermented milk was not observed during passage of the liquid.

[0056] (Sensory evaluation results) As shown in Table 2 above, in Examples 1 to 6, both the filling property and the smoothness were rated as ◯, and the overall evaluation was ◯. On the other hand, in Comparative Examples 1 to 7, at least one of the filling ability and the smoothness was rated Δ or ×, and the overall evaluation was Δ or ×. Regarding the filling property, if it was rated as △ or ◯, it was within a range sufficient for practical use.

[0057] (summary) According to the above measurement results and sensory evaluation results, the viscosity is related to the filling property of the fermented milk, and the maximum particle size in the particle size distribution and the proportion of residual curd are related to the smoothness of the fermented milk. In Examples 1 to 6, when the viscosity was 7500 to 9500 cP, it was evaluated that sufficient filling properties were obtained. Furthermore, in Examples 1 to 6, the maximum particle size in the particle size distribution was less than 700 μm and the curd residue rate was less than 10%, and therefore, sufficient smoothness was evaluated.

[0058] Specifically, the total cross-sectional area of ​​the holes 52 is 40 mm 2 When the linear velocity was 3.0 m / s or more (Examples 1 to 6, Comparative Examples 1, 3, and 5), the maximum particle size in the particle size distribution was less than 700 μm. In addition, the total cross-sectional area of ​​the holes 52 is 40 mm 2 and each of the holes 52 has a cross-sectional area of ​​7.5 mm 2 In the following cases (Examples 1 to 6), the card remaining ratio was less than 10%. In particular, among Examples 1 to 6, a tendency for the card remaining ratio to decrease was observed in Examples 3 and 6 in which the individual cross-sectional area of ​​holes 52 was small. Furthermore, when the group of Examples 1 to 3 was compared with the group of Examples 4 to 6, a tendency for the card remaining ratio to decrease was observed in Examples 1 to 3, which are the group in which the total cross-sectional area of ​​holes 52 was small and the linear speed was fast. In Comparative Examples 5 and 6, the total cross-sectional area of ​​holes 52 or the cross-sectional area of ​​each hole 52 was outside the above-mentioned condition, but the card remaining ratio was 10% or less. It is believed that the linear speed in Comparative Example 5 was higher than that in Examples 1 to 6, and that the cross-sectional area of ​​each hole 52 in Comparative Example 6 was small like Examples 3 and 6, which influenced the card remaining ratio. As a result, sufficient smoothness was achieved in Examples 1 to 6 and Comparative Example 5, in which the maximum particle size in the particle size distribution was less than 700 μm and the curd residue ratio was less than 10%. In Comparative Example 6, the maximum particle size in the particle size distribution was 700 μm or more, but the curd residue ratio was less than 10%, so some smoothness was achieved.

[0059] In addition, the total cross-sectional area of ​​the holes 52 is 20 mm 2 When the linear velocity was 6.0 m / s or less (Examples 1 to 6, Comparative Examples 1 to 4, 6, and 7), the viscosity was 7500 cP or more, and it was found that the filling property could be improved. 2 When the linear velocity is smaller than 6.0 m / s (Comparative Example 5), the viscosity is less than 7500 cP and the filling property is low.

[0060] In Examples 1 to 6, the cross-sectional area of ​​the hole 52 of the card crusher 5 is 0.5 mm 2 As described above, the opening of the device was sufficiently larger than that of a conventional curd crusher, and therefore no clogging of the device with fermented milk was observed during passage of the device. [Explanation of symbols]

[0061] 1...card crushing device, 2...hopper, 3...pump, 4...piping, 41, 42...joint portion, 411, 421...flange portion, 43...annular seal member, 5, 5A...card crushing tool, 51...plate portion, 52...hole, 53...pipe portion, 531, 532...joint portion, 6...discharge portion, 71...flow meter, 72...pressure meter, F...flow direction.

Claims

1. A curd crushing device to be placed in a pipe through which fermented milk containing curds flows, A plate portion having a plurality of holes penetrating in the flow direction of the fermented milk, The cross-sectional area of ​​each of the plurality of holes is 0.5 to 7.5 mm2; A card crushing tool, wherein the total cross-sectional area of ​​the plurality of holes is 20 to 40 mm2.

2. The cross-sectional area of ​​each of the plurality of holes is 0.8 to 7.1 mm2; The card crusher according to claim 1, wherein the total cross-sectional area of ​​the plurality of holes is 27.5 to 35.0 mm2.

3. The card crusher according to claim 2, wherein each of the plurality of holes has a cross-sectional area of ​​3.1 to 7.1 mm2.

4. The card crusher according to claim 1 , wherein the cross-sectional shape of the hole is circular.

5. The card crushing tool according to any one of claims 1 to 4, The card crushing device includes the pipe in which the card crushing tool is disposed.

6. The pipe further includes an annular seal member that is sandwiched between the first joint portion and the second joint portion of the pipe and has an inner diameter larger than an inner diameter of the pipe, The card crushing device according to claim 5 , wherein the plate portion is disposed radially inward of the annular seal member.

7. The method includes a crushing step of circulating fermented milk obtained by fermenting a fermented milk raw material through a pipe provided with a curd crushing device, and crushing the curds contained in the fermented milk, The card crushing tool has a plate portion having a plurality of holes passing through it along the flow direction of the fermented milk, The cross-sectional area of ​​each of the plurality of holes is 0.5 to 7.5 mm2; A method for producing fermented milk, wherein the total cross-sectional area of ​​the plurality of holes is 20 to 40 mm2.

8. The method includes a crushing step of circulating fermented milk obtained by fermenting a fermented milk raw material through a pipe provided with a curd crushing device, and crushing the curds contained in the fermented milk, The card crushing tool has a plate portion having a plurality of holes passing through it along the flow direction of the fermented milk, The cross-sectional area of ​​each of the plurality of holes is 0.5 to 7.5 mm2; In the crushing step, the fermented milk passes through the curd crusher at a linear velocity of 3.0 to 6.0 m / s.

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