Method for Heating Frozen Bread

Abstract

To provide a method of heating frozen bread, the method being capable of restoring the same quality as that of freshly baked bread in a very short time from frozen state.SOLUTION: A method of heating frozen bread according to the present invention implements a heating step of setting bread in its frozen state at -5°C to -25°C in a heat chamber of a heating device provided with a far infrared heater, steam supplying means, and microwave outputting means, and furthermore, in this heating step, the method starts far infrared heating by the far infrared heater, and starts steam heating by the steam supplying means and microwave heating by the microwave outputting means after the elapse of specified time (3 to 7 seconds after the start of the far infrared heating), and implements the steam heating and the microwave heating intermittently at intervals by setting implementation continuation time and stop time within in a range of 3 to 7 seconds.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for heating frozen bread, and particularly to a method for heating frozen bread for restoring quality (such as flavor, taste, and texture) equivalent to that immediately after baking.

Background Art

[0002] As a method for producing bread that can impart freeze resistance to baked bread and preferably avoid freezing damage, the method described in Patent Document 1 is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, natural thawing (standing at room temperature for 30 minutes or more) has been applied as a method for thawing bread produced by the above method and frozen. When set in a toaster or a microwave oven in a frozen state and subjected to far-infrared heating or microwave heating, there is a problem that the crust (outer skin) or crumb (inner layer) burns before the whole is thawed. Also, when set in a steamer in a frozen state and subjected to steam heating, there is a problem that it becomes softer than the freshly baked state and the crispy texture cannot be restored.

[0005] Therefore, as described above, first natural thawing is performed, and after thawing, reheating with a toaster or the like or finish baking is carried out as necessary to achieve restoration of quality equivalent to that immediately after baking. However, since natural thawing takes time, establishment of a method that can restore in a shorter time is required.

[0006] The present invention aims to solve the problems in the prior art as described above, and provides a method for heating a frozen bread that can restore the quality equivalent to that immediately after baking in an extremely short time from the frozen state.

Means for Solving the Problems

[0007] The method for heating a frozen bread according to the present invention is characterized in that a frozen bread in a frozen state of -5°C to -25°C is set in a heating chamber of a heating device having a far-infrared heater, a steam supply means, and a microwave output means, and a heating process is carried out. Further, in this heating process, far-infrared heating by the far-infrared heater is started, and after a specified time has elapsed, steam heating by the steam supply means and microwave heating by the microwave output means are started, and the steam heating and the microwave heating are intermittently carried out with an interval.

[0008] In addition, in this method for heating a frozen bread, it is preferable to start steam heating by the steam supply means and microwave heating by the microwave output means 3 to 7 seconds after the start of far-infrared heating. Also, it is preferable to set the execution duration and the stop time of the steam heating and the microwave heating within the range of 3 to 7 seconds and carry out the heating process. Further, it is preferable to set the output of the microwave heating to 400W to 800W and carry out the heating process.

[0009] Also, in this method of heating frozen bread, it is preferable to use bread manufactured by the method described in Japanese Patent No. 5255201. Specifically, it is a method for manufacturing breads in which a main raw material and a sub-raw material are mixed, kneaded to make a bread dough, fermented, baked, and then frozen. As one of the sub-raw materials, an emulsified oil and fat composition produced by mixing alkaline ionized water and edible oil and fat is mixed in the range of 1 to 20 parts by weight with respect to 100 parts by weight of the main raw material before kneading the main raw material, together with water. The water is alkalized by the alkaline ionized water contained in the emulsified oil and fat composition, and by kneading these, gluten is formed in the dough. After gluten is formed, the oil and fat is gradually added, and this oil and fat is evenly mixed to form a bread dough. Further, the emulsified oil and fat composition is obtained by mixing edible oil and fat in the range of 1 to 50 parts by weight with respect to 100 parts by weight of alkaline ionized water having a pH of 12 or more, mixing an appropriate amount of saccharides, stirring, and binding the atomized edible oil and fat to the alkaline ionized water by the surface active power of the alkaline ionized water to form an emulsion. Bread manufactured by the method for manufacturing breads is used.

Advantages of the Invention

[0010] According to the method for heating frozen bread according to the present invention, bread that has been once frozen after production (after baking) can be restored to a state having the same quality (flavor, taste, texture, etc.) as that immediately after baking in an extremely short time.

Embodiments for Carrying Out the Invention

[0011] The "method for heating frozen bread" according to the present invention basically involves setting bread in a frozen state (-5°C to -25°C) manufactured by a specific method in a heating chamber of a dedicated heating device and performing a heating process.

[0012] In this embodiment, bread manufactured by the method described in Japanese Patent No. 5255201 is used. Specifically, it is a method for manufacturing breads in which a main raw material and a sub-raw material are mixed, kneaded to make a bread starter, fermented, baked, and frozen. As one of the sub-raw materials, an emulsified oil and fat composition produced by mixing alkaline ionized water and edible oil and fat is mixed with 1 to 20 parts by weight with respect to 100 parts by weight of the main raw material before kneading the main raw material, together with water. The water is alkalized by the alkaline ionized water contained in the emulsified oil and fat composition, and by kneading these, gluten is formed in the dough. After the gluten is formed, the oil and fat is gradually added, and this oil and fat is evenly mixed to form a bread starter. Further, the emulsified oil and fat composition is obtained by mixing 1 to 50 parts by weight of edible oil and fat with respect to 100 parts by weight of alkaline ionized water having a pH of 12 or more, mixing an appropriate amount of saccharides, stirring, and binding the atomized edible oil and fat to the alkaline ionized water by the surface active force of the alkaline ionized water to form an emulsion. Bread manufactured by the method for manufacturing breads characterized by this is used.

[0013] The bread manufactured by this method is such that in the step of making the bread starter, before kneading the main raw materials (such as wheat flour, barley flour, rye flour), the water is modified by mixing the emulsified oil and fat composition together with sub-raw materials such as water, and freeze resistance is imparted to the baked breads. Even when frozen, no wrinkles occur on the surface of the bread dough, and it is possible to expect the effect that no property changes (freezing damage) such as shrinkage and deformation occur. Also, even after thawing, the texture of the bread dough does not collapse and is firm, and since the surface area of the bread dough directly in contact with air is small, it is also possible to expect the effect that aging of starch, protein, oil and fat, etc. is suppressed. Furthermore, due to the reducing action of the strongly alkaline alkaline ionized water contained in the emulsified oil and fat composition, oxidation of the breads is suppressed, and it is also possible to expect the effect that the flavor of the bread is sustained.

[0014] Regarding the bread produced by this method, as described above, natural thawing has conventionally been applied as the thawing method, but there has been a problem that it takes a very long time. In the present embodiment, the bread produced by the above method is set in the heating chamber of a dedicated heating device in a frozen state and the heating process is carried out, whereby the quality equivalent to that immediately after baking can be restored in an extremely short time.

[0015] In the present embodiment, as the heating device, a device having a far-infrared heater, a steam supply means, and a microwave output means is used. In this heating device, the far-infrared heaters are respectively arranged at the upper and lower parts of the heating chamber, and the bread set in the heating chamber can be heated from the upper side and the lower side. Further, these far-infrared heaters are configured so that the heating temperature can be set individually.

[0016] The steam supply means is composed of a tank, a boiler, etc., and is configured to boil the water supplied from the tank by the boiler and supply the generated high-temperature steam into the heating chamber.

[0017] The microwave output means is configured to generate microwaves by applying a high voltage to the built-in magnetron and output them into the heating chamber. Note that the output of the microwaves can be switched in three steps (strong: 1100W, medium: 800W, weak: 500W) by default, and furthermore, fine adjustment is possible.

[0018] When this heating device starts the heating process, first, heating by the far-infrared heaters (far-infrared heating) is started, and after a specified time has elapsed (in the present embodiment, after 5 seconds (it can also be 3 to 7 seconds)), the supply of steam (steam heating) from the steam supply means is started, and at the same time, the output of microwaves (microwave heating) from the microwave output means is started.

[0019] Far-infrared heating is carried out continuously, while steam heating and microwave heating are carried out intermittently with intervals. In this embodiment, both the execution duration and the stop time are set to 5 seconds. After steam heating and microwave heating are continuously executed for 5 seconds, they are stopped for 5 seconds, and this cycle is repeated until the end of the heating process. Incidentally, the execution duration and the stop time can be changed within the range of 3 to 7 seconds respectively.

[0020] Thus, in the method according to this embodiment, the bread manufactured by the above method is set in a heating device having a far-infrared heater, a steam supply means, and a microwave output means, and far-infrared heating, steam heating, and microwave heating are executed simultaneously, and steam heating and microwave heating are started 5 seconds after the start of far-infrared heating and executed intermittently, whereby the quality equivalent to that immediately after baking can be restored. Moreover, the required time for the heating process is about 3 minutes (2 to 5 minutes), and the required time can be significantly shortened compared with the conventional method of natural thawing.

[0021] Here, the operation in the heating process will be briefly described. When only far-infrared heating or microwave heating is executed to heat the frozen bread, the contained moisture evaporates into the air and the bread dries out, and the quality immediately after baking cannot be restored. In this embodiment, steam heating is executed together with far-infrared heating and microwave heating, and steam condenses on the surface of the bread to supplement the moisture, so that over-drying of the bread can be avoided.

[0022] Also, when only steam heating is executed, the crust becomes overly soft and the crispness is impaired. In this embodiment, since far-infrared heating and steam heating are executed simultaneously, while avoiding over-drying of the bread, the surface of the crust can be re-baked to achieve a crispy finish, and the quality equivalent to that immediately after baking can be restored.

[0023] Still, in the initial stage of the heating process, the crust and crumb of the bread are in a frozen state. When steam is supplied in this state, water droplets at 100 °C adhere (condense) to the surface of the crust. As thermal energy (latent heat) is continuously supplied, moisture penetrates into the crumb. As a result, not only the crust but also the crumb starts to thaw, and the thawing area gradually spreads from the outside to the inside. However, immediately after thawing, it remains at a low temperature close to 0 °C.

[0024] After passing the initial stage, the temperature of the crust rises due to far-infrared heating. When the surface temperature of the crust exceeds 100 °C, condensation no longer occurs, and the surface starts to dry. When it reaches 180 °C, the Maillard reaction occurs, and it approaches a crispy state. The crust of the bread is basically completed by the initial baking during production. However, after going through the frozen state, by returning to the state where moisture is retained due to steam condensation in this heating process, the heat exchange film is regenerated, and by rebaking the crust by far-infrared heating (Maillard reaction), the dry heat-insulating layer is regenerated.

[0025] Microwaves have a limited effect on ice crystals but act effectively on melted moisture. Specifically, it can rapidly heat by vibrating the electrons of water molecules. As described above, due to the steam heating in the initial stage, moisture penetrates into the crumb, and thawing progresses from the outside to the inside of the crumb. However, immediately after thawing, it remains at a low temperature close to 0 °C. When microwave heating is performed, the low-temperature moisture in the crumb can be rapidly heated, promoting thawing and raising the temperature of the crumb to an appropriate temperature (the same temperature as immediately after baking) in a short time.

[0026] The crust of the bread is in a sponge-like structure, with a low overall moisture content and uneven moisture distribution (a mixture of parts with high and low moisture content). Therefore, if the output of microwave heating is too strong, the temperature of the part with a high moisture content will become abnormally high (heating unevenness), and only that part will dry out and become hard. For this reason, the output of microwave heating is preferably set to about 500 W (400 W to 800 W) and intermittently implemented with intervals.

[0027] Here, the inventors of the present invention will explain, as examples of the present invention, the results of various experiments conducted regarding the heating method of the frozen bread according to the present invention.

Example

[0028] First, 11 types of bread produced by the method described in Japanese Patent No. 5255201 were prepared, and they were set in the heating chamber of the heating device in a frozen state (-5°C to -25°C) and the heating process was executed.

[0029] As the heating device, a device having a far-infrared heater, a steam supply means, and a microwave output means was used. It was set so that steam heating and microwave heating would start 5 seconds after the start of far-infrared heating. Furthermore, far-infrared heating was continuously executed, and steam heating and microwave heating were intermittently implemented (execution duration 5 seconds, stop time 5 seconds) for heating.

[0030] In addition, conditions such as the number (pieces) of bread set in the heating chamber, the microwave output (W), the heating time (minutes), and the temperature of the far-infrared heater (upper fire temperature (°C), lower fire temperature (°C)) were individually set for each type of bread. These conditions and the finished temperature (°C) (temperature at the end of the heating process) are shown in the following table.

[0031]

Table 1

[0032] The finished state of each loaf was as follows: The croissants had slightly soft crusts immediately after being removed from the heating device, but became crispy once cooled. For the melon bread, the granulated sugar sprinkled on top of the crust melted slightly. For the cheese bread, the amount of cheese in the center was large, so the crust was soft and the temperature reached 50°C, but the cheese temperature was lower at 32-40°C. However, this was improved by adding residual heat. The sides of the cheese and onion crust were soft. The sausage roll had a fluffy crumb, and the sausage felt slightly cold immediately after taking it out, but once it cooled down it was about the same temperature as the bread.

[0033] The bottom of the crust of the French anpan became slightly harder. The chocolate bread was fluffy, but still had a bit of a core to it. The raisin bread was not too soft and tasted just right. Baguette A had a crispy crust. The crust of Bucket B was a little soft. The batard's crust went from soft to crispy after 30 minutes. The broadcloth had some hard cores in some areas.

[0034] As mentioned above, the finished state varied depending on the type of bread, but all breads were able to restore flavor, taste, and texture almost identical to that of immediately after baking. Furthermore, it is assumed that some of the problems identified (melting of granulated sugar, remaining core, etc.) can be resolved by simply making slight adjustments to microwave output, heating time, top heat temperature, bottom heat temperature, etc.

Claims

1. A method for heating a frozen bread by setting a bread in a frozen state at -5°C to -25°C in a heating chamber of a heating device having a far-infrared heater, a steam supply means, and a microwave output means, and performing a heating process, comprising: In the heating process, starting far-infrared heating by the far-infrared heater, and after a lapse of a specified time, starting steam heating by the steam supply means and microwave heating by the microwave output means; Continuously performing the far-infrared heating; A method for heating a frozen bread, characterized in that the steam heating and the microwave heating are intermittently and simultaneously performed with an interval therebetween.

2. The method for heating a frozen bread according to claim 1, characterized in that the steam heating by the steam supply means and the microwave heating by the microwave output means are started 3 to 7 seconds after the start of the far-infrared heating.

3. The method for heating a frozen bread according to claim 1, characterized in that the heating process is performed by setting the continuous execution time and the stop time of the steam heating and the microwave heating within a range of 3 to 7 seconds.

4. The method for heating a frozen bread according to claim 1, characterized in that the heating process is performed by setting the output of the microwave heating to 400 W to 800 W.

5. A method for manufacturing breads, comprising mixing a main ingredient and a sub-ingredient, kneading them to make a bread dough, fermenting this, baking it, and then freezing it. As one of the sub-ingredients, an emulsified oil and fat composition produced by mixing alkaline ionized water and edible oil and fat is mixed in a range of 1 to 20 parts by weight with respect to 100 parts by weight of the main ingredient, together with water, before kneading the main ingredient. The water is alkalized by the alkaline ionized water contained in the emulsified oil and fat composition, and by kneading these, gluten is formed in the dough. After the gluten is formed, the oil and fat is gradually added, and this oil and fat is evenly mixed to form a bread dough. Further, the emulsified oil and fat composition is obtained by mixing edible oil and fat in a range of 1 to 50 parts by weight with respect to 100 parts by weight of alkaline ionized water having a pH of 12 or more, and stirring to bind the micronized edible oil and fat to the alkaline ionized water by the surface active force of the alkaline ionized water to form an emulsion. The method for heating a frozen bread according to any one of claims 1 to 4, characterized by using bread manufactured by the method for manufacturing breads.

Images