TW201343074A - Milk fat cream and method of manufacturing same - Google Patents

Abstract

The present invention provides a milk fat cream with excellent emulsion stability and favorable whipping characteristics, which offers the favorable flavor of milk, does not use emulsifiers and other stabilizing additives, and does not require requiring special equipment or complex procedures in its manufacture. By homogenizing raw milk at 2.0 to 5.0 MPa prior to the cream separation step before recovering the cream layer by centrifugal separation, a milk fat cream with excellent emulsion stability and favorable whipping characteristics is obtained.

Description

Milk fat cream and its manufacturing method

The present invention relates to novel milk fat creams and methods of making the same. In the present invention, the term "milk fat cream" refers to a provincial order related to the composition specifications of the milk and the dairy product (December 27, 26th, December 26th, 26th, and the Ministry of Health and Welfare, No. 52, hereinafter referred to as "milk and other provincial orders"). The definition of "category cream".

In general, what is called cream, in addition to milk fat cream composed only of milk fat, there are emulsifiers and stabilizers added to milk fat, emulsifiers and stabilizers added to vegetable fats, Add emulsifier and stabilizer to the mixed fat of milk fat and vegetable fat. In the case of milk and other provincial orders, only milk fat cream is defined as "classified cream", and other emulsifiers and stabilizers (hereinafter referred to as "synthetic cream") are defined as "milk or dairy products as the main raw material." food".

When making confectionery, making bread, and making desserts, milk fat cream and synthetic fat are used, but in recent years, there is a tendency to prefer milk fat cream from the viewpoint of not using additives at all. Synthetic cream has a high degree of freedom in the selection of fats and oils, and a combination of emulsifiers and stabilizers has various advantages, so it has the advantage of providing products excellent in whipping and emulsifying stability, however, compared to milk Fat cream, lacking aromatic alcohol and fresh milk flavor, has the disadvantage of poor flavor.

Milk fat cream is generally a cream that is separated from milk, or a fat that is separated from milk. The rationale is that the fat is adjusted by raw milk, and then homogenized, sterilized, rehomogenized, and cooled. Milk fat cream has a unique flavor and concentrated alcohol of milk fat, and is superior in flavor to synthetic cream. In definition, emulsifier and stabilizer for providing stability cannot be added, in order to impart whipping property and emulsion stability. Physical properties must be implemented entirely by the control of manufacturing conditions. Therefore, there is a problem that the whipping property and the emulsion stability are inferior to those of the synthetic cream. Regarding the improvement of the emulsion stability of the milk fat cream, there has been proposed a method of suppressing the fat layer by homogenizing before and after the sterilization step by the UHT method (Patent Document 1), but this method cannot Ample emulsion stability is obtained. Moreover, it has been proposed to cool the step after the heat treatment of the cream, first rapidly cooling to 7 ° C ~ 25 ° C, at this temperature for 1 minute ~ 30 minutes, then rapidly cooling to 3 ° C ~ 5 ° C, thereby giving emulsion stability Method (Patent Document 2). However, in this method, the vibration resistance at the time of cold storage is given, but the temperature treatment resistance is not given, and it is not preferable in terms of emulsion stability.

In addition, a cream manufacturing method which is excellent in flavor and physical properties of raw milk by membrane concentration treatment and deoxidation treatment has been proposed for the production of milk fat cream (Patent Document 3). However, this method requires special equipment and complexity in manufacturing. In addition to the steps, although the obtained milk fat cream has improved flavor, the emulsion stability is not sufficient.

[Previous Technical Literature]

[Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2007-259831

Patent Document 2: Japanese Laid-Open Patent Publication No. 2006-325426

Patent Document 3: Japanese Laid-Open Patent Publication No. 2006-141273

An object of the present invention is to provide a milk fat cream which is excellent in emulsion stability and has good whipping properties.

The present invention is as follows.

(1) A milk fat cream characterized in that the median diameter of the fat globule is 2.4 μm or less, and in the fat globule membrane, the mass ratio of casein to milk protein is 3.5 or less. (2) A method for producing a milk fat cream comprising the steps of: a cream separation step of separating the cream from the raw milk; and a cream sterilization step of sterilizing the separated cream separated by the cream separation step; characterized in that: the cream Before the separation step, a raw material milk homogenization step of homogenizing the raw material milk is included.

(3) The method for producing a milk fat cream according to (2), wherein the homogenization pressure of the raw material milk homogenization step is 2.0 MPa to 5.0 MPa.

(4) The method for producing a milk fat cream according to (2) or (3), wherein before the cream sterilization step and/or after the cream sterilization step, a cream homogenization treatment step of homogenizing the separated cream is included .

According to the present invention, a milk fat cream excellent in emulsification stability and having good whipping property can be obtained.

Hereinafter, the present invention will be described in more detail.

The milk fat cream of the present invention refers to a "classified cream" such as milk, and does not contain an additive such as an emulsifier or a stabilizer. Milk fat cream, usually produced by the following steps: a cream separation step, passing the raw milk through a disc-type centrifuge, separating the cream and skim milk; a cream sterilization step, sterilizing the separated cream; a cream cooling step, after sterilization The cream is cooled. Further, a cream homogenizing step of homogenizing the cream may be performed before the sterilization step and/or after the sterilization step as needed. The milk fat cream of the present invention is characterized in that a raw material milk homogenizing step of performing homogenization treatment on the raw material milk is carried out before the cream separation step in addition to the above steps.

The milk fat cream of the present invention is characterized in that the median diameter of the fat globule is 2.4 μm or less and the mass ratio of casein to milk protein in the fat globule membrane is obtained by a homogenization step of the raw material milk (hereinafter referred to as The "casein/lactal protein ratio" is 3.5 or less. In the present invention, the median diameter is a particle diameter corresponding to 50% of the cumulative distribution curve based on the volume, and can be measured, for example, by a laser diffraction type particle size distribution measuring apparatus (SALD-3100, manufactured by Shimadzu Corporation).

In the cream homogenization step which has been carried out in the past, the high-fat cream is subjected to a homogenization treatment, and if the homogenization treatment is carried out at a high homogenization pressure of, for example, 2.0 MPa or more, the protein of the fat globule having an increased surface area due to the pulverization is coated. Insufficient amount, agglomeration or union between fat globules occurs. Therefore, in the cream homogenization step, the homogenization treatment is generally performed using a low homogenization pressure of less than 2.0 MPa, but when the homogenization pressure is repeatedly performed so that the median diameter of the fat globule becomes 2.4 μm or less, the casein of the fat globule membrane is used. / Milky white protein becomes larger than 3.5. On the contrary, in order to reduce the homogenization pressure and reduce the number of homogenizations when the casein/lactoprotein ratio of the fat globule membrane is less than 3.5, the median diameter of the fat globule cannot be 2.4 μm or less.

In the present invention, by using a raw material milk homogenizing step of homogenizing the raw material milk, the median diameter of the fat globule can be 2.4 μm or less, and the casein/lactoprotein ratio of the fat globule membrane is 3.5 or less, and by satisfying Under such conditions, a milk fat cream having both emulsion stability and whipping property can be obtained.

In the raw material milk homogenization step, the raw material milk is heated to a specific homogenization temperature, and then homogenized by a homogenizer. For the heating of the raw material milk, a flat type heat exchanger, a batch type heating machine, or the like can be used. Among them, from the viewpoint of the heating efficiency of the raw material milk, it is preferred to use a flat plate heat exchanger. Further, in the case of homogenization, a homogenizer such as a homogenizer or the like may be used, such as a high-pressure nano-homogenizer or a colloid mill. From the viewpoint of the homogenization efficiency of the raw milk and the ability to handle the amount, it is preferred to use a homogenizer, and it is preferable to use a two-stage homogenizer. Further, the homogenization pressure can be appropriately changed depending on the type of the homogenizer, the treatment flow rate of the raw material milk, the shape of the homo valve, the homogenization temperature, and the like, and for example, it can be treated with a high homogenization pressure of 2.0 MPa or more. .

Moreover, the cream separation step and the cream sterilization step can be carried out by using a suitable method. In the cream separation step, it may be carried out by a disk type centrifugal separator or the like. Moreover, the cream sterilization step can be carried out under the following conditions, for example, maintaining a sterilization method of 63 ° C for 30 minutes, a plate type heat exchange sterilization method of 72 to 75 ° C for 15 seconds, and 82 to 85 ° C for 10 seconds of high-temperature short-time sterilization. (HTST method) or ultra-high temperature sterilization method (UHT method) of 130 to 140 ° C for 2 seconds. Further, in general, the cream subjected to the sterilization step is immediately cooled to 10 ° C or lower, but the cream homogenization step may be carried out before and after the cream sterilization step. The cream homogenization step can be carried out according to the existing method. For example, the homogenization treatment can be carried out at a homogenization pressure of about 1.0 MPa.

Hereinafter, the present invention will be described by way of examples, reference examples and test examples, but the present invention is not limited thereto.

[Example 1]

The raw material milk which had been heated to 60 ° C was homogenized at a homogenization pressure of 2.0 MPa, and then a cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was passed through a plate sterilizer, and sterilizing treatment was performed at 120 ° C for 2 seconds. After the sterilization, the plate was cooled to about 50 ° C, and then 700 g of cream was collected in a bag and cooled to obtain a milk fat cream (Example 1). The resulting milk fat cream was stored at 5 °C.

[Example 2]

The raw material milk which had been heated to 60 ° C was homogenized in a homogenizer at a homogenization pressure of 2.0 MPa, and then a cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was homogenized at a homogenization pressure of 1.0 MPa, and then passed through a plate sterilizer to carry out sterilization treatment at 120 ° C for 2 seconds. Thereafter, after cooling the plate to about 50 ° C, 700 g of cream was collected into a bag and cooled to obtain a milk fat cream (Example 2). The resulting milk fat cream was stored at 5 °C.

[Example 3]

The raw material milk which had been heated to 60 ° C was homogenized at a homogenization pressure of 2.0 MPa, and then a cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was homogenized at a homogenization pressure of 1.0 MPa, and then passed through a plate sterilizer to carry out sterilization treatment at 120 ° C for 2 seconds. Thereafter, after the plate was cooled to about 50 ° C, the homogenization treatment was again performed at a homogenization pressure of 1.0 MPa, and milk was collected. 700 g of oil was placed in a bag and cooled to obtain a milk fat cream (Example 3). The resulting milk fat cream was stored at 5 °C.

[Embodiment 4]

The raw material milk which had been heated to 60 ° C was homogenized at a homogenization pressure of 2.0 MPa, and then a cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was passed through a plate sterilizer, and subjected to sterilization treatment at 120 ° C for 2 seconds. Thereafter, the plate was cooled to about 50 ° C, and then homogenized at a homogenization pressure of 1.0 MPa, and 700 g of the cream after homogenization treatment was collected. The bag was cooled to obtain milk fat cream (Example 4). The resulting milk fat cream was stored at 5 °C.

[Comparative Example 1]

After the raw milk was warmed to 60 ° C, the cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was passed through a plate sterilizer, and subjected to sterilization treatment at 120 ° C for 2 seconds. Thereafter, the plate was cooled to about 50 ° C, and then homogenized at a homogenization pressure of 1.0 MPa, and 700 g of the cream after homogenization treatment was collected. The bag was cooled to obtain milk fat cream (Comparative Example 1). The resulting milk fat cream was stored at 5 °C.

[Comparative Example 2]

After the raw milk was warmed to 60 ° C, the cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was homogenized at a homogenization pressure of 1.0 MPa, and then passed through a plate sterilizer to carry out sterilization treatment at 120 ° C for 2 seconds. Thereafter, the plate was cooled to about 50 ° C, and homogenization was carried out at a homogenization pressure of 1.0 MPa. 700 g of the cream after the homogenization treatment was collected in a bag, and cooled to obtain a milk fat cream (Comparative Example 2). The resulting milk fat cream was stored at 5 °C.

After the raw milk was warmed to 60 ° C, the cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was homogenized at a homogenization pressure of 1.0 MPa, passed through a plate sterilizer, and subjected to sterilization treatment at 120 ° C for 2 seconds. Thereafter, the plate was cooled to about 50° C., and 700 g of cream was collected in a bag and cooled to obtain a milk fat cream (Comparative Example 3). The resulting milk fat cream was stored at 5 °C.

[Comparative Example 4]

After the raw milk was warmed to 60 ° C, the cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was passed through a plate sterilizer, and sterilizing treatment was performed at 120 ° C for 2 seconds. Thereafter, the plate was cooled to about 50° C., and after homogenization treatment at a homogenization pressure of 2.0 MPa, 700 g of cream was collected into a bag and cooled to obtain a milk fat cream (Comparative Example 4). The resulting milk fat cream was stored at 5 °C.

[Comparative Example 5]

After the raw milk was warmed to 60 ° C, the cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was passed through a plate sterilizer, and sterilizing treatment was performed at 120 ° C for 2 seconds. Thereafter, the plate was cooled to about 50° C., and homogenized at a homogenization pressure of 5.0 MPa, and then 700 g of cream was collected in a bag and cooled to obtain a milk fat cream (Comparative Example 5). The resulting milk fat cream was stored at 5 °C.

[Test Example 1]

For the example products 1 to 4 and the comparative examples 1 to 5, the median diameter of the fat globule was measured. Further, the protein composition analysis of the fat globule membrane was carried out to calculate the casein/lactal protein ratio of the fat globule membrane.

For the measurement of the median diameter of the fat globule, a laser diffraction type particle size distribution measuring apparatus (SALD-3100, manufactured by Shimadzu Corporation) was used.

The protein composition analysis of the fat globule membrane was carried out by the following method.

250 g of ultrapure water was added to 150 g of each level of cream, diluted, and centrifuged at 2,500 rpm and 5 ° C for 20 minutes to discard the lower aqueous layer. 300 g of ultrapure water was added to the remaining cream layer, diluted, and centrifuged again, and the lower layer was discarded. This operation was carried out twice to recover the cream layer. After 15 g of hexane was added to 25 g of the recovered cream layer and mixed, the mixture was centrifuged at 1000 rpm and 25 ° C for 5 minutes to remove the lipid in the upper layer of hexane and the cream layer as a sample. 10 g of the obtained sample was centrifuged at 15,000 rpm and 5 ° C for 30 minutes using Amicon Ultra Ultrace-3K, and concentrated. 4 g of the concentrated sample was weighed, and 5000 μl of 0.1 MBis Tris buffer (pH 6.8) containing 5.37 mM sodium citrate and 6 M guanidine hydrochloride was added to 300 μl of 1 MDTT and mixed, and the sample was solubilized. After adjusting to pH 8.2 with 1 N-NaOH, distilled water was added to make a volume to 10 ml. It Thereafter, 1 ml to 1.5 ml microtubes were taken and allowed to cool to room temperature by heating in boiling water for 3 minutes. Thereafter, 300 μl of the mixture was mixed with 900 μl of the diluent, and injected into a high performance liquid chromatography (HPLC). The dilution composition was used after dissolving hydrazine hydrochloride in the mobile phase A described below to have a final concentration of 4.5 M. A high performance liquid chromatograph apparatus was used by connecting ELITE Lachrom (manufactured by Hitachi High-Technologies Co., Ltd.) to a PDA detector (manufactured by Hitachi High-Technologies Co., Ltd.). The column was an ODS-3 column (diameter: 4.6 mm × length: 250 mm, manufactured by GL Sciences). The sample injection amount was 40 μl, the column temperature was 25 ° C, the flow rate was 1.2 ml/min, and detection was performed at 220 nm. The mobile phase uses acetonitrile/water = 1/9 (mobile phase A) containing 0.1% TFA, acetonitrile/water = 9/1 (mobile phase B) containing 0.1% TFA, and the ratio of mobile phase B is from the beginning of 27% to After 32 minutes, 32% after 12 minutes, 34% after 12 minutes, 36.5% after 17 minutes, 39% after 35 minutes, 43.5% after 50 minutes, and 80% concentration gradient after 52 minutes, the column was eluted. The elution peaks were determined by the elution position of the standard (Sigma-Aldrich). Α-lactalbumin, β-lactoglobulin, and κ-casein are calculated from the peak area values using the calibration lines obtained from the respective standards. Α-casein and β-casein are the values of all the protein amounts of the samples injected into the HPLC, minus the masses of α-lactalbumin, β-lactoglobulin, and κ-casein, which are defined as α-casein, β. - the total mass of casein. From the total mass of α-lactalbumin and β-lactoglobulin obtained, and the ratio of the total mass of α-casein, β-casein, and κ-casein, the mass ratio of casein to milk protein can be calculated. (casein/lactal protein ratio).

[Test Example 2]

In Examples 1 to 4 and Comparative Examples 1 to 5, a vibration resistance test as an index of emulsification stability and a foaming test at the time of whipping as a whipping property index were carried out.

(Vibration tolerance test)

The vibration resistance test is a case where the cream is prepared and stored at 5 ° C for 24 hours, and after being subjected to temporary temperature treatment (25 ° C, 1 hour warm bath) and stored at 5 ° C for 24 hours (thermal shock (HS) 25 ° C treated product Each of 200 g was placed in a carton container having a capacity of 250 ml, and the number of times until the fat was solidified when the vibration was applied at 167 times/min at 20 ° C was determined.

The evaluation of the emulsion stability was carried out in two stages of ○ and ╳ by a vibration resistance test (5° C. preserved product, thermal shock (HS) 25° C. treated product). Specifically, the number of vibrations of the stored product at 5 ° C is 10,000. The number of times of vibration of the HS25°C treated product of 8,000 or more was evaluated as ○, and any one who did not satisfy the above conditions was rated as ╳.

(Foaming test at the time of whipping)

In the foaming test at the time of whipping, the load indicating the optimum flowering property when the cream was whipped with a mixer (manufactured by GENERAL ELECTRIC) was set as the end point of the whipping, and the time to reach the end point (whipping time) and the whipping were measured. The time from the start of the bubble to the end point (△ whipping time). Further, the weight of the cream in a predetermined volume before and after the whipping was measured, and the expansion ratio of the cream reaching the end of the whipping was determined by the following formula.

Expansion ratio = ((W1-W2)/W2) × 100 (%)

W1: the weight of the cream before the whipping of a certain volume

W2: the weight of the cream after a certain volume of whipping

In addition, the hardness of the cream which reached the end of the whipping was measured by a rheometer (CR-200D, manufactured by SUN SCIENTIFIC Co., Ltd.) under the conditions of a plunger diameter of 20 mm, an intrusion depth of 10 mm, and a gantry speed of 60 mm/min.

In the evaluation, the whipping time, the whipping time, the expansion ratio, and the hardness were comprehensively evaluated in two stages of ○ and ╳. Specifically, the whipping time is 18 minutes or less, the Δ whipping time is 2 minutes or more, the expansion ratio is 100% or more, the hardness is 20 gf or more and less than 30 gf is evaluated as ○, and those not satisfying the conditions are evaluated as ╳. Further, the Δ whipping time indicates the time from the value of 1/10 of the set hardness (load 25 gf) of the whipped cream to the time when the set hardness is reached. The results of Test Example 1 and Test Example 2 are summarized as shown in Table 1.

As shown in Table 1, with respect to the examples 1 to 4, the emulsion stability was drastically improved under the conditions of the 5 ° C preserved product and the HS 25 ° C treated product as compared with the comparative examples 1 to 3. Also, foaming evaluation In the comparison with Comparative Example 1 and Comparative Example 3, the Δ whipping time was long, the expansion ratio was also increased, and the desired hardness was easily whipped. Understand: In the examples 1 to 4, no significant difference was observed. The number of homogenizations hardly affected the cream properties, and only the raw milk was homogenized to obtain the desired effect. Moreover, it is understood from the comparative example 4 that when the homogenization treatment is performed after the cream is separated, the emulsion stability is lowered even if the homogenization pressure is increased to reduce the fat globule diameter. Further, from Comparative Example 5, it was found that homogenization treatment was carried out at a homogenization pressure of 5.0 MPa after separation of the cream, and aggregation occurred during the homogenization process, and the cream could not be prepared.

[Embodiment 5]

The raw material milk which had been heated to 60 ° C was homogenized at a homogenization pressure of 5.0 MPa, and then a cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was passed through a plate sterilizer, and sterilizing treatment was performed at 120 ° C for 2 seconds. After the sterilization, the plate was cooled to about 50 ° C, and then 700 g of cream was collected into a bag and cooled to obtain a milk fat cream (Example 5). The resulting milk fat cream was stored at 5 °C.

[Comparative Example 6]

After the raw milk was warmed to 60 ° C, homogenization treatment was carried out at a homogenization pressure of 0.0 MPa, and then a cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was passed through a plate sterilizer, and sterilizing treatment was performed at 120 ° C for 2 seconds. After the sterilization, the plate was cooled to about 50 ° C, and then 700 g of cream was collected in a bag and cooled to obtain a milk fat cream (Comparative Example 6). The resulting milk fat cream was stored at 5 °C.

[Comparative Example 7]

After the raw material milk was warmed to 60 ° C, homogenization treatment was carried out at a homogenization pressure of 1.0 Mpa, and then a cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was passed through a plate sterilizer, and sterilizing treatment was performed at 120 ° C for 2 seconds. After the sterilization, the plate was cooled to about 50 ° C, and then 700 g of cream was collected in a bag and cooled to obtain a milk fat cream (Comparative Example 7). The resulting milk fat cream was stored at 5 °C.

[Comparative Example 8]

The raw milk which has been heated to 60 ° C is homogenized at a homogenization pressure of 8.0 MPa, and then The centrifuge separates the cream with a fat percentage of 45%. The obtained cream was passed through a plate sterilizer, and sterilizing treatment was performed at 120 ° C for 2 seconds. After the sterilization, the plate was cooled to about 50 ° C, and then 700 g of cream was collected in a bag and cooled to obtain a milk fat cream (Comparative Example 8). The resulting milk fat cream was stored at 5 °C.

[Comparative Example 9]

The raw material milk which had been heated to 60 ° C was homogenized at a homogenization pressure of 10.0 MPa, and then a cream having a fat percentage of 45% was separated by a centrifugal separator. The obtained cream was passed through a plate sterilizer, and sterilizing treatment was performed at 120 ° C for 2 seconds. After the sterilization, the plate was cooled to about 50 ° C, and then 700 g of cream was collected in a bag and cooled to obtain a milk fat cream (Comparative Example 9). The resulting milk fat cream was stored at 5 °C.

[Test Example 3]

With respect to Example 1, Example 5, and Comparative Examples 6 to 9, the measurement of the median diameter of the fat globule and the casein/white of the fat globule membrane were carried out by the same method as Test Example 1 and Test Example 2. Calculation of protein ratio, vibration resistance test and foaming test during whipping. The results are shown in Table 2.

As shown in Table 2, in the examples 1 and 5, the emulsion stability was drastically improved in comparison with the comparative examples 6 and 7, under the conditions of the 5 ° C preserved product and the HS 25 ° C treated product. Further, in the evaluation of the foaming property, the Δ whipping time was long, the expansion ratio was also improved, and the desired hardness was easily whipped. In Comparative Examples 8 and 9, the emulsion stability was improved as compared with the examples 1 and 5, but the whipping time was remarkably extended, so that it was not suitable as a whipping cream.

Claims (4)

A milk fat cream characterized in that the median diameter of the fat globule is 2.4 μm or less, and in the fat globule membrane, the mass ratio of casein to milk protein is 3.5 or less. The method for producing a milk fat cream comprises the steps of: a cream separation step of separating the cream from the raw milk; and a cream sterilization step of sterilizing the cream separated by the cream separation step; characterized by: including before the cream separation step The raw material milk homogenization step of homogenizing the raw material milk. The method for producing a milk fat cream according to the second aspect of the invention, wherein the homogenization pressure of the raw material milk homogenization step is 2.0 MPa to 5.0 MPa. The method for producing a milk fat cream according to the second or third aspect of the invention, wherein before the cream sterilization step and/or after the cream sterilization step, a cream homogenization treatment step of homogenizing the separated cream is included.