JP7379050B2 - Foods, food production methods, and evaluation methods - Google Patents

Description

The present invention relates to water-in-oil type emulsified oil and fat foods, such as butter, used as raw materials for confectionery and bread, and the present invention relates to water-in-oil type emulsified oil and fat foods, such as butter, which are used as raw materials for confectionery and bread. The present invention relates to a water-in-oil emulsified oil/fat food that can provide unique characteristics and texture, a method for producing the same, and a method for estimating the secondary processing characteristics of the water-in-oil emulsified oil/fat food.

BACKGROUND OF THE INVENTION Butter, margarine, and fat spreads, that is, water-in-oil emulsified oil and fat foods, are used as raw materials for confectionery such as pies, bread such as croissants, and so-called layered puffed foods. At that time, the dough is kneaded with flour, salt, and water, and is woven repeatedly to form a layered form. At this time, the appropriate hardness and spreadability of the water-in-oil type emulsified oil and fat food will affect the properties such as the specific volume (swelling) and suds (density of the cross-sectional layer) of pies and croissants after baking, as well as the so-called crispy and mushy texture. It is an important factor that determines texture such as texture.
Therefore, in the production of layered puffed foods with good properties, the suitability for secondary processing of water-in-oil emulsified oil and fat foods is estimated, and based on this, the hardness and spreadability of water-in-oil emulsified oil and fat foods are determined. Adjusting and selecting physical properties is an important task.

Conventionally, the suitability of water-in-oil emulsified oil and fat foods for secondary processing has been estimated by measuring the physical properties of the water-in-oil emulsified oil and fat foods. Methods for measuring the physical properties of water-in-oil emulsified oil and fat foods include cutting the water-in-oil emulsified oil and fat food into a certain shape and calculating the storage modulus and loss modulus using a dynamic viscoelasticity meter, and using a texture analyzer to measure the physical properties of the food. There was a method of calculating the compression distance vs. stress curve during compression while recording the load using a device equipped with a load cell that can measure the amount of stress, but this method requires work in a low-temperature room, which is complicated and time-consuming.

The present invention was made to solve these problems, and has been developed to improve suitability for secondary processing such as specific volume and sudsiness, and texture of water-in-oil emulsified oil and fat foods such as butter used as raw materials for confectionery and pie making. The purpose of the present invention is to provide a water-in-oil emulsified oil/fat food that exhibits good properties, and to provide a method for easily and quickly estimating the suitability of a water-in-oil emulsified oil/fat food for secondary processing.

In order to solve these problems, the present invention includes the following technical means.
(1) Aggregates composed of plate-shaped crystals with a circumference of ² μm or more are found in the 125 μm2 field of view of the image in which the Young's modulus was calculated from the force curve measured using an atomic force microscope for a water-in-oil emulsified oil/fat food. A water-in-oil emulsified fat food, characterized in that it is present in less than 20% of the entire visual field of 125 μm ² .
(2) Aggregates composed of plate-shaped crystals with a circumference of ² μm or more are found in the 125 μm2 field of view of the image in which the Young's modulus was calculated from the force curve measured using an atomic force microscope for a water-in-oil emulsified oil/fat food. A water-in-oil emulsion, which is present in 20% or more and 30% or less of the entire field of view of 125 μm ² , and in which a region with a Young's modulus of 50 MPa or more at 5° C. existing inside the aggregate is 60% or less. Fatty foods.
(3) A method for producing a water-in-oil emulsified oil/fat food according to (1) or (2), in which the cream composed of 30% by weight or more and 50% by weight or less of milk fat is sterilized, and then the cooling rate of the cream is adjusted. A method for producing a water-in-oil emulsified fat and oil food, which includes a cooling step of 1°C/min or more and reaching a temperature of -5°C to 0°C.
(4) The water-in-oil of (3) is provided with a step of raising the temperature of the cream by 7°C to 17°C from the reached temperature in the cream heating step after the cooling step of (3), and sending the liquid to the churning step. A method for producing emulsified oil and fat foods.
(5) A method for estimating the suitability for secondary processing of water-in-oil emulsified oil and fat foods, which consists of plate-like crystals with a circumference of 2 μm or more in a field of 125 μm ² observed with an atomic force microscope. less than 20% of the aggregates, or the aggregates are present in 20% or more and 30% or less, and the area where the Young's modulus at 5° C. present inside the aggregates is 50 MPa or more is 60%. A method for estimating suitability for secondary processing of a water-in-oil type emulsified oil/fat food based on the following:

The present invention enables good secondary processing characteristics to be achieved without requiring work in a low-temperature room or complicated work that takes a long time, which was necessary in evaluating the suitability for secondary processing of conventional water-in-oil emulsified oil and fat foods. It is now possible to provide water-in-oil emulsified oil and fat foods that have the following properties. Furthermore, it is possible to provide a method for easily estimating the suitability for secondary processing of water-in-oil emulsified oil and fat foods.

FIG. 1 shows the appearance of an atomic force microscope used in the present invention. FIG. 2 shows an image of Young's modulus calculated using an atomic force microscope.

The hardness and spreadability of water-in-oil emulsified oil and fat foods affect secondary processing characteristics such as specific volume (swelling) and suds (density of cross-sectional layers) of baked pies and croissants, as well as crispy and soft texture. As mentioned above, it is an important factor that determines the texture of the food.
The present invention estimates the suitability for secondary processing of such water-in-oil emulsified fat and oil foods using an atomic force microscope. This is the first feature of the present invention.
In the present invention, since we have decided to estimate these properties using an atomic force microscope, secondary processing of water-in-oil emulsified fat and oil foods can be easily, quickly, and accurately compared to estimation methods in conventional technology. Now we can evaluate the suitability.
This point is a new finding obtained in the present invention, and has remarkable effects that cannot be predicted from the conventional technology.

Atomic Force Microscope (AFM) is a type of microscope that detects the atomic force that acts on the probe and the sample, and measures the force curve generated between the probe and the sample to determine Young's modulus. can be calculated. The force curve is a graph in which the vertical axis represents the force acting on the probe, that is, the cantilever, and the sample surface, and the horizontal axis represents the distance between the cantilever and the sample. First, the force curve is scanned horizontally by a specified pixel, then vertically moved by one pixel, and horizontally scanned by a specified pixel. This is repeated until the specified pixel is reached in the vertical direction to obtain force curves for all the specified number of pixels. After that, the Young's modulus is calculated for all the force curves obtained, and the surface state is imaged.

In the present invention, FIG. 1 schematically shows how a section cut out from a water-in-oil emulsified oil/fat food is measured using an atomic force microscope. However, the present invention is not interpreted as being limited to this form. The cut section 5 of the water-in-oil emulsified fat food is placed in ultrapure water 6, placed on the stage 3, and observed through the head unit 1 of an atomic force microscope.

In the present invention, we focused on the physical properties of aggregates observed on the surface of water-in-oil emulsified oil-fat foods as a factor that influences the properties of layered puffed foods using water-in-oil emulsified oil-fat foods. This is the second feature of the present invention. This aggregate is an aggregation of plate-shaped crystals (Crystal nano platelets (CNPs)).

In the present invention, the hardness of water-in-oil emulsified oil and fat foods can be improved by setting the size of the aggregates, the area ratio occupying the ¹²⁵ μm field of view of AFM, and the ratio of the high Young's modulus region to appropriate ranges. Spreadability can be adjusted, and as a result, layered puffed foods with good properties can be produced. Furthermore, by observing aggregates in a water-in-oil emulsified oil-fat food using AFM, it is possible to estimate whether the water-in-oil emulsified oil-fat food is suitable for secondary processing. This point is also a new finding discovered by the present invention, and cannot be predicted from the conventional technology.

In other words, according to the present invention, water-in-oil emulsified fat and oil foods have good suitability for secondary processing if the area ratio of aggregates with a circumference of 2 μm or more in a field of view of 125 ^μm2 is less than 20%. Similarly, even if the area ratio is 20% or more and 30% or less, a water-in-oil type in which the area with a Young's modulus of 50 MPa or more at 5°C existing inside the aggregate is 60% or less If it is an emulsified oil/fat food, it can be said that it has similarly good suitability for secondary processing.

No theoretical investigation has been made regarding the mechanism by which aggregates in a water-in-oil emulsified oil-fat food affect the suitability for secondary processing of the water-in-oil emulsified oil-fat food. However, it is preferable that large aggregates with a circumferential length of 2 μm or more do not exist in water-in-oil emulsified fat/oil foods, and even if some are present, the proportion of high Young's modulus regions is low, that is, the overall Young's modulus is low. If the amount of aggregates is low, the water-in-oil emulsified fat/oil food will have good suitability for secondary processing. This became clear from the measurement results of Examples and Comparative Examples below.

In the atomic force microscope used in the present invention, a field of view of 125 μm ² can be observed. In the present invention, in order to improve the resolution, observation was performed five or more times with a field of view of 25 μm ² . The area of aggregates with a circumferential length of 2 μm or more made of plate-shaped crystals that could be confirmed in this visual field was measured, and the area ratio of the aggregates was counted.
Further, the Young's modulus of the aggregate was calculated as follows.
The probe of the atomic force microscope is brought close to the surface of each aggregate to be analyzed, and the force curve of each plate-like crystal is obtained based on the amount of deformation of the aggregate and the force generated on the probe. Then, the Young's modulus of each aggregate was calculated from this force curve. An example of an aggregate is shown in FIG.
The high Young's modulus region is defined as the region indicated by the broken line in FIG. 2, where the Young's modulus at 5° C. calculated from the force curve is 50 MPa or more.

In the present invention, water-in-oil emulsified oil and fat foods were observed using an atomic force microscope by submerged observation.
Further, the means for calculating Young's modulus is not limited to an atomic force microscope as long as it can obtain a force curve. In other words, it is a scanning probe microscope, which is a general term for microscopes that observe the sample surface three-dimensionally while detecting the mechanical and electrical interactions between the probe and the sample, and is used to observe water-in-oil emulsified foods. You can use anything you can.

Details of the observation using an atomic force microscope are as follows.
The water-in-oil emulsified fat food was cut into rectangles of 1 cm ³ or less using a razor blade in a low-temperature room set at 6°C. Thereafter, it was transferred to a microtome whose temperature was controlled at -20°C, and 500 μm sections were prepared. The section was moved to a petri dish for observation using an atomic force microscope Nanowizard 4 (manufactured by Barker, hereinafter referred to as AFM). Thereafter, ultrapure water cooled to 5° C. was added, and a force curve was obtained in QI mode, which is a mode for obtaining force curves of this device. Young's modulus was calculated by applying special analysis software to this force curve. The setpoint, which is the threshold for approaching the cantilever to the specified load, was 1 nN to 10 nN, and the image was acquired at 256 x 256 pixels.
Furthermore, the number and area ratio of aggregates were calculated from the obtained Young's modulus image. The image analysis software is WinROOF2018 Ver. 4.3.0 (manufactured by Mitani Shoji Co., Ltd.) was used.
The cantilever used was Biolever mini BL-AC40TS-C2 (manufactured by Olympus), which has a spring constant of 0.1 N/m and a resonance frequency in the atmosphere of 110 kHz. The cantilever is preferably a relatively soft cantilever with a low spring constant. The microtome used was Cryostar NX50 (manufactured by Thermo Fisher Scientific).
The device and cantilever are not limited to these, and any device that can obtain a force curve may be used. Force curves were obtained while maintaining the temperature at 5°C.

The method for producing a water-in-oil emulsified fat/oil food with good suitability for secondary processing in the present invention is as follows.
Skimmed milk etc. are added to the cream to adjust the milk fat percentage to 30 to 50% by weight, and after sterilization, the cooling rate is 1°C using a normal cooling method such as passing the liquid through two stages using a plate heat exchanger. Cooling is performed at a temperature of -50° C. to 0° C. at a speed of at least /min. Thereafter, if necessary, by employing a normal temperature raising method, the temperature is raised from the above-mentioned reached temperature by 7°C to 17°C in the cream heating step. After that, the liquid is sent to the churn and churning is performed.
Through such a manufacturing process, less than 20% ^{of the aggregates composed of plate-shaped crystals and having a circumference of 2 μm or more exist in the 125 μm 2 field} of view, or the aggregates is present in 20% or more and 30% or less of the entire field of view of 125 μm ² , and the area with a Young's modulus of 50 MPa or more at 5°C existing inside the aggregate is 60% or less. can be manufactured.

(1) Method for evaluating the spreadability of a water-in-oil emulsified oil-fat food The spreadability of the water-in-oil emulsified oil-fat food for baked layered foods of the present invention is evaluated by evaluating the spreadability of the water-in-oil emulsified oil-fat food when folding a pie. It means to grow with. Spreadability can be evaluated by the following fold pie test. The folded pie evaluation was performed 30 days after the butter was manufactured.
The day before the test date, the baked layered food-grade butter is left in a constant temperature machine at 13° C. to temper it. Knead the pie ingredients in Table 1 using a food mixer at low speed for 3 minutes and medium speed for 5 minutes. Divide the resulting dough into equal parts and form into squares 2 to 3 cm thick at 13°C. Store in a thermostatic oven until Wrap the baked layered food-grade butter in the dough, press it diagonally using a rolling pin, and roll the baked layered food-grade butter into the dough. After that, the fabric is folded in the order of three folds, four folds, three folds, and three folds, and between each folding process, the fabric is stretched thinly in 5 steps from 20 mm to 5 mm using a pie roller MR120 (Seijo Kikai Co., Ltd.). , evaluate the condition of the butter and dough at this time.

(2) Method for evaluating sudashi and float (specific volume) after baking the pie Cut the dough stretched to 5 mm into 10 cm x 10 cm squares, make cuts in the four corners and the center, and place in the oven COMPO (Sanko Kikai Co., Ltd.) ), the temperature was set at 210°C for the top surface and 200°C for the bottom surface, and firing was performed for 13 minutes. The day after firing, the weight and the height, length and width of the upper surface, and length and width of the lower surface were measured using a caliper, and the volume, specific volume, upper side deformation rate, and lower side deformation rate were calculated.

(Examples 1 to 6)
Cream whose fat percentage was adjusted to a predetermined value with skim milk was sterilized at 88° C. for 15 seconds, and the cream was cooled by passing the liquid through a plate heat exchanger in two stages. Cooling was performed so that the cooling rate and the temperature reached were set to predetermined values. Thereafter, the mixture was sufficiently aged for 6 hours or more to raise the temperature to a predetermined temperature, and the mixture was sent to a churn to produce butter according to a conventional method. Thereafter, it was molded into a size of 22 cm x 23 cm x 1 cm and stored at 6°C. A section was prepared at −20° C. using a temperature-setting microtome, and the section was placed in a Petri dish for observation in an atomic force microscope Nanowizard 4 (manufactured by Bruker). 4 ml of ultrapure water was added to the petri dish, and the temperature was set at 5° C. to conduct underwater observation. The pie was also baked 30 days after the date of manufacture. The manufacturing conditions are shown in Table 2, and the evaluation results are shown in Tables 3 and 4.
In addition, the aggregates in "area ratio of aggregates" in Tables 3 and 4 are those with a circumferential length of 2 μm or more.

(Comparative Examples 1 to 5)
Cream whose fat percentage was adjusted with skim milk was sterilized at 88° C. for 15 seconds, and the cream was cooled by passing the liquid through a plate heat exchanger in two stages. Thereafter, it was molded into a size of 22 cm x 23 cm x 1 cm and stored at 6°C. Thereafter, observation using AFM was performed in the same manner as in the example. The pie was also baked 30 days after the date of manufacture.

The evaluation criteria for each evaluation item are as follows, and a comprehensive evaluation was performed taking into consideration the evaluation contents of these individual evaluation items.
Evaluation criteria for spreadability ◎: The butter is spread evenly between the doughs 〇: The butter is spread between the doughs △: There are parts where the butter is not spread ×: The butter is spread evenly between the doughs Evaluation criteria for texture where unstretched parts are frequently observed ◎: The desired texture (crispy, soft and fluffy) is sufficiently imparted. 〇: The desired texture (crispy, soft and fluffy) is achieved. ) is given △: A certain degree of desired texture (crispy, soft and fluffy) is imparted. ×: Evaluation criteria for floats that do not have the desired texture (crispy, soft and fluffy) ◎ : Showing good "floating" ○: Forming "floating" typical of layered food △: Very weak "floating" ×: Evaluation criteria for sudachi with no "floating" typical of layered food ◎: Inner layer 〇: Forms a “sudachi” characteristic of a layered food △: “Sudachi” can be observed but is extremely weak ×: “Sudachi” is not observed Comprehensive sensory evaluation ◎: 3 or more ◎ 〇: 3 or more 〇 △: 3 or more △ ×: 3 or more ×

In Examples 1 to 4, the area ratio of aggregates with a circumference of 2 μm or more in the water-in-oil emulsified fat/oil food specified by the present invention was less than 20%, and therefore received good evaluation in various properties. ing. In addition, in Examples 5 and 6, the area ratio of aggregates was 20% or more and 30% or less, but the high Young's modulus region was 60% or less, so similarly good evaluations were obtained in various properties. Is receiving.
In addition, the water-in-oil emulsified fat and oil food having aggregates within the range specified in the present invention is prepared by sterilizing cream composed of 30% by weight or more and 50% by weight or less of milk fat at a cooling rate of 1°C/ It was confirmed that the product can be manufactured by cooling the cream to a temperature of -5°C to 0°C for more than 10 minutes, then raising the cream temperature to room temperature from the achieved temperature by 7°C to 17°C, and sending the liquid to the churning process. .

1: Atomic force microscope (head unit)
2: Cantilever
3: Stage 4: Cooling stage 5: Water-in-oil emulsified oil/fat food 6: Ultrapure water

Claims (5)

In the 125 μm ² field of view of the image in which the Young's modulus was calculated from the force curve of a water-in-oil emulsified oil/fat food measured with an atomic force microscope, there was an aggregate of 125 μm ² composed of plate-shaped crystals with a circumference of 2 μm or more. A water-in-oil emulsified fat food, characterized in that it is present in less than 20% of the entire visual field. In the 125 μm ² field of view of the image in which the Young's modulus was calculated from the force curve of a water-in-oil emulsified oil/fat food measured with an atomic force microscope, there was an aggregate of 125 μm ² composed of plate-shaped crystals with a circumference of 2 μm or more. A water-in-oil emulsified oil and fat, which is present in 20% or more and 30% or less of the entire field of view, and in which a region with a Young's modulus of 50 MPa or more at 5° C. existing inside the aggregate is 31.0 % or less. food. The method for producing a water-in-oil emulsified fat/oil food according to claim 1 or 2, wherein the cream composed of 30% by weight or more and 50% by weight or less of milk fat is sterilized, and then the cream cooling rate is 1° C./min or more. , and a method for producing a water-in-oil emulsified fat and oil food, comprising a cooling step to reach a temperature of -5°C to 0°C. The water-in-oil type according to claim 3, further comprising a step of raising the temperature of the cream by 7° C. to 17° C. from the final temperature in a cream heating step after the cooling step of claim 3, and sending the liquid to the churning step. Method for producing emulsified oil and fat food. This is a method for estimating the suitability for secondary processing of water-in-oil emulsified oil and fat foods, in which aggregates composed of plate-shaped crystals with a circumference of 2 μm or more are observed in a field of 125 μm ² observed with an atomic force microscope. The aggregate content is less than 20%, or the aggregate content is 20% or more and 30% or less, and the area within the aggregates with a Young's modulus of 50 MPa or more at 5°C is 31.0 % or less. A method for estimating the suitability of water-in-oil emulsified oil and fat foods for secondary processing.