JP4925788B2 - Fly product manufacturing method and vacuum fryer - Google Patents

Description

  The present invention relates to a method of manufacturing a fried product, and more particularly to a method of manufacturing a fried product from a raw material with a vacuum fryer. The invention also relates to a vacuum fryer operating in such a way.

  2. Description of the Related Art Conventionally, a method for manufacturing a fried product by putting materials such as potatoes and fruits into a vacuum fryer's fry basket is known. For example, it is a method of putting a raw material into a frying product by putting the raw material into a frying basket of a vacuum fryer and putting the frying basket into or out of the fryer oil (see, for example, Patent Document 1).

JP-A-1-269458

Attempting to manufacture a fried product using the conventional methods described above may not work. For example, if an onion snack, which is a fried product of onion pieces that have been cut into pieces, is to be produced by a conventional method, heat is applied only to the outside of the dough, resulting in a defective product with the outside burned. Also, if the heat is stopped before it is burnt, the water in the center cannot be completely removed, so that it becomes a so-called raw state, which also becomes a defective product. In addition, when the onion pieces stick together due to the sugar that comes out of the onion, and the frying is finished as it is, it becomes a defective product in which the stuck part remains in a raw state.
In addition, the conventional method has room for reducing the amount of oil necessary to produce a fried product.

Accordingly, a first object of the present invention is to provide a fly product manufacturing method and a vacuum fryer capable of reducing defective products when a raw material is made into a fly product.
The second object of the present invention is to provide a frying product manufacturing method and a vacuum fryer capable of reducing the amount of oil necessary for manufacturing a frying product.

  The inventor of the present invention cuts and shears a raw material such as an onion or the like in that it has a structure in which internal moisture hardly moves to the cut surface (dehydrated surface) portion, for example, the entire surface area of the cut material. Focusing on the fact that the area ratio is 70% or less, and as a result of diligent efforts based on this focus point, the present invention could be achieved.

  In order to achieve the first object, a method for producing a fried product according to the present invention is a method for producing a fried product from a raw material with a vacuum fryer, wherein the raw material is submerged under an oil surface of the vacuum fryer. The first frying process for frying in a state, the filing of the material in an oil state after the first frying step, and the frying in an oil surface state where the material is floated near the oil surface are alternately performed. A second frying process that repeats in one cycle, and after the second frying process, the material is fried in an oil state, the material is fried in an oil surface state, or the material is in the air above the oil surface. The third in the second cycle is alternately repeated in a second cycle shorter than the first cycle so that the time in the oil state is the same as or shorter than the time in the oil level state or the air position. And having a frying process To have.

  According to the fly product manufacturing method of the present invention configured as described above, since the material is fried in the oil in the first frying step, the heat of the oil is actively transmitted to the material, In particular, water near the cut surface is evaporated in a short time. Next, in the second frying step, by combining that the material is fried in an oil surface state, heating of the surface of the material is suppressed, and the progress of scoring of the surface is suppressed, while the heat near the material surface is heated. It moves to the inside, and heating is continued inside the material. As a result, the moisture at the center of the material moves toward the cut surface. In the third frying process, by increasing the ratio of the oil level fly time to the oil level fly time, or by replacing the oil level fly time with the time to lift to the air position, Further suppresses the progress of scorching. Moreover, the heat | fever which the raw material has moves the water | moisture content inside a raw material to a cut surface, and the water in a part far from a cut surface is evaporated slowly. As a result, it is possible to reduce defective products in which the material is burnt and defective products in which the inside of the material is raw.

  In addition, the term “fly” used in the present specification means heating with oil.

  In this frying product manufacturing method, preferably, the material is stirred when the material is fried in an oil state and when the material is fried in an oil surface state.

  In the fly product manufacturing method configured in this way, the heat of oil is more actively transmitted to the material, and the heat transfer efficiency is improved, so that the amount of oil necessary to manufacture the fly product can be reduced. The second object of the invention can be achieved.

In the fly product manufacturing method of the present invention, preferably, when the moisture content of the material is 40 to 95%, the first frying process is shifted to the second frying step, and the moisture content of the material is 5 to 40%. Then, the process proceeds from the second frying process to the third frying process.
Moreover, in the frying product manufacturing method of this invention, Preferably, the time of the oil surface state in the 1st period of a 2nd frying process and the time of the oil surface state in the 2nd period of a 3rd frying process Are the same.
In the method for producing a fried product of the present invention, the material is preferably an onion.

  In order to achieve the first object and the second object, a vacuum fryer according to the present invention is a vacuum fryer provided with a fly cage having a top surface and a bottom surface, and the fly cage is an oil surface of the vacuum fryer. A first frying process that rotates in an oil state submerged under the ground, and after the first frying process, the fly basket is rotated in an oil state, and the top surface of the frying basket is positioned above the oil level. And rotating the fly cage in an oil surface state whose bottom surface is located below the oil surface, a second fly step that alternately repeats in a first cycle, and a fly cage after the second fly step. Rotating in the oil state, rotating the fly cage in the oil level state, or lifting the fly cage to an air position above the oil level, the time in the oil state is in the oil level state or in the air. Same as time at position or To be shorter than Re, and characterized in that it is automatically controlled so as to perform a third frying process repeated in the first second period shorter than the period alternately, the sequentially.

  In order to achieve the first object, a vacuum fryer according to the present invention is a vacuum fryer disposed in a vacuum chamber, and includes an oil tank extending from an upstream side to a downstream side, and a material to be fried in the oil tank. A transport conveyor for transporting from the upstream side to the downstream side, and the transport conveyor has an upper net conveyor belt and a lower net conveyor belt facing each other, and the material is an upper net conveyor belt and a lower side The upper net conveyor belt is transported while being positioned between the net conveyor belt, and the upper net conveyor belt travels below the oil level in the oil tank, and downstream of the first frying process unit, A second frying process unit that repeats traveling at a level lower than the oil level and traveling at a level higher than the oil level at a first pitch; In the downstream of the section, traveling below the oil level and traveling above the oil level, the distance traveled below the oil level is above the oil level. And a third fly process section that repeats alternately at a second pitch shorter than the first pitch so as to be equal to or shorter than the distance traveled on the level.

With the fly product manufacturing method and the vacuum fryer of the present invention, defective products can be reduced when the raw material is made into a fly product.
Moreover, the amount of oil required for manufacturing a fly product can be reduced by the fly product manufacturing method and vacuum fryer of this invention.

  First, with reference to FIGS. 1-3, 1st Embodiment of the vacuum fryer by this invention used for the frying product manufacturing method by this invention is described. The vacuum fryer which is the first embodiment of the present invention is a batch type vacuum fryer. FIG. 1 is a schematic view of a vacuum fryer with a later-described fly cage in an oil position. FIG. 2 is a schematic view of a vacuum fryer with a later-described fly cage at the oil level. FIG. 3 is a schematic view of a vacuum fryer in a state where a fly cage described later lifts the top lid of the frying container.

  As shown in FIG. 1, a vacuum fryer 1 according to a first embodiment of the present invention includes a frying container 2 that contains oil, an upper lid 4 that can seal the frying container 2, and a vacuum that evacuates the inside of the frying container 2. A device 5, a heater 6 for heating the frying container 2, a frying basket 8 disposed in the frying container 2, and an in-oil position 8 a (see FIG. 1) in which the entire frying basket 8 is submerged in oil; A drive unit 12 for moving the fly cage 8 up and down between the oil level position 8b (see FIG. 2) where the fly cage 8 is submerged in half oil and rotating the fly cage 2 around the vertical axis 10; And a controller 13 for operating the driving device 12.

  The frying basket 8 has a closed structure so as to surround the whole material to be made into a frying product. The fly cage 8 has a top surface 9 and side and bottom surfaces with holes through which oil passes. In addition, the fly basket 8 has an openable / closable opening (not shown) for loading and unloading the material.

  The driving device 12 includes a frame 14 provided so as to straddle the fly container 2, a support part 16 attached to the frame 14 so as to be vertically movable above the fly container 2, and the support part 16 and the fly through the upper lid 4. A rotary shaft 18 connected to the car 8 and supported by the support 16 so as to be rotatable about the vertical axis 10, and a vertical drive device 20 for moving the support 16, the rotary shaft 18 and the fly basket 8 up and down. And a rotation drive device 22 for rotating the rotary shaft 18.

  The frame 14 has a rail 24 extending in the vertical direction. The support portion 16 includes an upper support 26 and a lower support 28 that are slidable along the rail 24 and are disposed above and below each other with a space therebetween. The body 28 is connected to each other by a screw jack device 30. In the present embodiment, the vertical drive device 20 is an air cylinder unit 20 provided between the frame 14 and the upper support 26. The air cylinder unit 20 has a rod 32 connected to the upper support 26, and the rod 32 moves the fly cage 8 between an in-oil position 8 a (see FIG. 1) and an oil level position 8 b (see FIG. 2). Can be moved between the extended position 32a (see FIG. 1) and the retracted position 32b (see FIG. 2). Further, the air cylinder unit 20 includes sensors 34 and 36 for detecting that the rod 32 is in the extended position 32a and the retracted position 32b. In this embodiment, the rotation drive device 22 is a motor 22 with a reduction gear that can rotate in both directions. The motor 22 is attached to the lower support 28. The distance between the upper support 26 and the lower support 28 can be changed by the screw jack device 30. Specifically, when the rod 32 is at the extended position 32a, the fly cage 8 is disposed at the in-oil position 8a. In addition, when the rod 32 is at the retracted position 32b, a first interval D1 (see FIGS. 1 and 2) for disposing the fly cage 8 at the oil level position 8b and when the rod 32 is at the retracted position 32b Can be changed between the second interval D2 (see FIG. 3) for lifting the upper lid 4.

  The air cylinder unit 20, the sensors 34 and 36, the motor 22, and the screw jack device 30 are electrically connected to the controller 13.

  Next, a first embodiment of the method for manufacturing a fried product according to the present invention will be described by taking as an example the case of frying an onion using the above-described vacuum fryer.

  The onion material to be used is an onion piece obtained by randomly cutting or cutting an onion. The water content of the onion is, for example, 75 to 80%. The oil to be used is, for example, rapeseed oil, rice oil, palm oil, palm olein, olive oil, peanut oil, cottonseed oil, soybean oil, and the temperature of the oil is preferably 70 to 150 ° C.

  As a preparatory step, the controller 13 is operated to bring the rod 32 of the air cylinder unit 20 into the retracted position 32b, and the screw jack device 30 sets the distance between the upper support 26 and the lower support 28 as shown in FIG. The interval D2 is set to 2. As a result, the fly basket 8 lifts the upper lid 4 from the fly container 2. Next, the onion, which is the raw material, is put into a fry basket 8. The volume of onion to be placed in the frying basket 8 is preferably about one third of the frying basket volume. Moreover, the heater 6 is operated and the oil in the frying container 2 is heated.

  Next, a first frying process is performed in which the onion pieces are stirred while fried in an oil-filled state below the oil level L of the vacuum fryer 1. Specifically, as shown in FIG. 1, the controller 13 is operated, the rod 32 of the air cylinder unit 20 is set to the extended position 32a, and the screw jack 30 is used to set the distance between the upper support 26 and the lower support 28 to the first. The interval D1 is set to 1. As a result, the entire basket 8 is submerged in the oil, and the basket 8 is brought into the oil position 8a. In addition, when the upper lid 4 is connected to the fly container 2 in a sealing manner and the fly cage 8 is above the oil level L, the inside of the fly container 2 is evacuated by the vacuum device 5. It is preferable that the pressure in the frying container 2 is 0-31.3 kPa (absolute pressure) through the frying process demonstrated below. Further, by operating the controller 13, the motor 22 is rotated, and the fly cage 8 is rotated around the vertical axis 10 at the in-oil position 8 a. The rotation of the fly cage 8 is preferably performed alternately in both directions. The time for one rotation and the time for the other rotation may be the same time or different times.

  Since the entire fly basket 8 is submerged in the oil, the onion pieces are forced to be submerged below the oil level L by the top surface 9 of the fly basket 8. At this time, the onion piece is heated by the oil, and the temperature of the oil in the vicinity of the onion piece decreases. However, since the frying basket 8 is rotating, the onion pieces are agitated and the surrounding oil is also agitated, and the heat of the hot oil is actively transmitted to each onion piece, and the moisture of the onion pieces, in particular, cutting. The water near the surface is evaporated in a short time. Also, the onion pieces gather on the top surface 9 of the fly basket 8, but the onion pieces adhere to the top surface 9 of the fly basket 8 due to the sugar that has come out of the onion pieces because the fly basket rotates in both directions. And the onion pieces stick to each other to prevent heat transfer from becoming uneven.

  Next, the onion pieces are stirred while being fried in an oil state and the onion pieces are stirred while being fried in an oil level state where the onion pieces are floated in the vicinity of the oil level L. 2 frying process is performed. It is preferable for the efficient frying operation that the in-oil time in the oil state is longer than the oil surface time in the oil surface state. Specifically, the controller 13 is operated, and the rod 32 of the air cylinder unit 20 is extended to the extended position 32a (see FIG. 5) while maintaining the distance between the upper support 26 and the lower support 28 at the first distance D1. 1) and the retracted position 32b (see FIG. 2). As a result, the fly cage 8 is alternately moved between the in-oil position 8a and the oil level position 8b. In addition, the motor 22 is operated to rotate the fly cage 8 at the oil-in-position 8a and the oil surface position 8b. The rotation of the fly cage 8 is preferably performed alternately in both directions. The time for one rotation and the time for the other rotation may be the same time or different times. The first period is preferably 40 to 60 seconds. For example, the oil level time is 30 seconds or more and 60 seconds or less, while the oil level time is 1 second or more and less than 30 seconds.

  The timing of shifting from the first frying step to the second frying step is preferably when dehydration proceeds in part of the translucent onion piece and the onion piece is partially white. Or the said timing is preferable when the water | moisture content of an onion is 40 to 95%, and when the water | moisture content of an onion is 55 to 65% in order to shorten the time of the whole frying operation | work, it is still more preferable.

When the fly basket 8 is in the oil position 8a, it is the same as the first frying process.
When the fly basket 8 is at the oil level position 8b, the onion piece is in a state of floating near the oil level L, and the heat transfer efficiency from the oil to the onion piece is lower than when it is in the oil state. Thereby, the heating of the surface of the onion piece is suppressed and the progress of the burning of the surface is suppressed, while the heat near the surface of the onion piece moves to the inside, and the heating is continuously performed inside the material. As a result, the water | moisture content of the center part of an onion piece moves toward a cut surface. Since the fly basket 8 is rotating, the onion pieces floating in the vicinity of the oil level L are agitated, and the heat transfer efficiency to each onion piece becomes uniform.

  Next, stirring the material while being fried at the oil level and stirring while filing the material at the oil level position are the same as or shorter than the time at the oil level position. In this manner, a third fly process is performed that is alternately repeated at a second cycle shorter than the first cycle. The specific operation is the same as in the second frying process. The second period is preferably 2 to 45 seconds. For example, the oil level time is 1 second or more and 15 seconds or less, while the oil time is 1 second or more and 30 seconds or less.

  The timing for shifting from the second frying process to the third frying process is preferably when a part of the onion piece begins to burn. Or the said timing is preferable when the water | moisture content of an onion is 5-40%, and in order to shorten the time of the whole frying operation | work, when the water | moisture content of an onion is 15-25% is still more preferable.

  The vacuum fryer 1 is preferably controlled automatically by the controller 13 so that the first to third frying steps are performed in order.

  By increasing the ratio of the oil surface time to the oil-in-time, the second period is made shorter than the first period, thereby further suppressing the progress of the surface burning. Moreover, the heat | fever which an onion piece has has the water | moisture content inside an onion piece to a cut surface part, and the water | moisture content in a part far from a cut surface is evaporated slowly. After the third frying step, the onion water content is preferably 0.5 to 3%. Ultimately, it is possible to significantly reduce defective products in which the onion pieces are scorched or the inside of the onion pieces is raw.

  Next, with reference to FIG.4 and FIG.5, 2nd Embodiment of the vacuum fryer by this invention used for the frying product manufacturing method by this invention is described. The vacuum fryer which is the second embodiment of the present invention is a continuous vacuum fryer. FIG. 4 is a schematic front sectional view of a vacuum fryer according to a second embodiment of the present invention. 5 is a partial cross-sectional side view of the upper and lower conveyors of the vacuum fryer of FIG.

  As shown in FIG. 4, a vacuum fryer 50 according to a second embodiment of the present invention is arranged in a vacuum chamber 52, and includes an oil tank 54 extending from an upstream side 50a to a downstream side 50b, and a material to be fried. A certain onion piece T is provided in the oil tank 54 and is conveyed from the upstream side 50a to the downstream side 50b. A supply device 58 for supplying the onion piece T is disposed on the upstream side of the transport conveyor 56, and an oil removing machine 60 for deoiling the onion piece T after frying is disposed on the downstream side of the transport conveyor 56. . The transfer conveyor 56 includes a lower conveyor 62 and an upper conveyor 64 positioned above the lower conveyor 62.

  The lower conveyor 62 includes an endless lower net conveyor belt 62c that travels on an upper forward path 62a and a lower return path 62b, and a drive roller 62d that drives the lower net conveyor 62c. The forward path 62a and the return path 62b of the lower net conveyor belt 62c are supported by a plurality of rollers 62e. Further, as shown in FIG. 5, lower guides 66 are provided on both sides of the lower net conveyor belt 62c so that the lower net conveyor belt 62c travels along a predetermined path to be described later. A follower 68 that can move along the lower guide 66 is attached to the side of the side net conveyor belt 62c.

  As shown in FIG. 4, the upper conveyor 64 includes an endless upper net conveyor belt 64c that travels on a lower forward path 64a and an upper return path 64b, and a driving roller 64d that drives the upper net conveyor 64c. Have. The forward path 64a and the return path 64b of the upper net conveyor belt 64c are supported by a plurality of rollers 64e. Further, as shown in FIG. 5, on both sides of the upper net conveyor belt 64c, upper guides 70 are provided so that the upper net conveyor belt 64c travels along a predetermined path to be described later. A follower 72 that moves along the upper guide 70 is attached to the side of the belt 64c.

  As shown in FIG. 4, the forward path 62a of the lower net conveyor belt 62c and the forward path 64a of the upper net conveyor belt 64c are opposed to each other and have a traveling path having substantially the same distance from the upstream side 50a to the downstream side 50b. is doing. Moreover, the conveyance conveyor 56 has the 1st fly process part 74, the 2nd fly process part 76, and the 3rd fly process part 78 toward the downstream 50b from the upstream 50a. Hereinafter, traveling paths of the lower net conveyor belt 62c and the upper net conveyor belt 64c will be described.

  In the first frying process unit 74, the upper net conveyor belt 64c travels a level L1 below the oil level L0 in the oil tank 54, and the lower net conveyor 62c travels below the upper net conveyor belt 64c. Thus, the upper guide 70 and the lower guide 66 are arranged.

  In the second frying process unit 76, the upper net conveyor belt 64c alternately travels the level L1 below the oil level L0 and the level L2 above the oil level L0. The upper guide 70 is arranged so as to be repeated at a pitch P1 of 1. Further, when the upper net conveyor belt 64c travels at a level L2 above the oil level, the lower guide 66 so that the lower net conveyor belt 62c travels at a level L3 just below the oil level L0. Is arranged.

  The first pitch or distance P1 is preferably determined along with the transport speed of the lower conveyor 62 and the upper conveyor 64 so that the onion pieces pass through it in 40-60 seconds. Further, in one pitch, for example, the time that the upper net conveyor belt 64c travels the level L1 below the oil level L0 is 30 seconds or more and 60 seconds or less, whereas the level above the oil level L0. It is preferable that the length and shape of the lower guide 66 and the upper guide 70 are determined so that the time for traveling in L2 is 1 second or more and less than 30 seconds.

  In the third frying process unit 78, the upper net conveyor belt 64c travels the level L1 below the oil level L0 and travels the level L2 above the oil level L0. The second pitch P2 that is alternately shorter than the first pitch P1 so that the distance traveling on the lower level L1 is the same as or shorter than the distance traveling on the level L2 above the oil level L0. The upper guide 70 is arranged so as to be repeated. Further, when the upper net conveyor belt 64c travels the level L2 above the oil level L0, the lower net conveyor belt 62c travels the level L3 immediately below the oil level L0, or the oil level L0. A lower guide 66 is arranged so as to travel above the level (not shown).

  The second pitch or distance P2 is preferably determined along with the transport speed of the lower conveyor 62 and the upper conveyor 64 so that the onion pieces pass through it in 2-45 seconds. Further, for example, the time for the upper net conveyor belt 64c to travel on the level L1 below the oil level L0 is 1 second or more and 30 seconds or less within one pitch, whereas the level above the oil level L0. It is preferable that the length and shape of the lower guide 66 and the upper guide 70 are determined so that the time for traveling in L2 is 1 second or more and 15 seconds or less.

  Next, a second embodiment of the method for manufacturing a fried product according to the present invention will be described by taking as an example the case of frying an onion using the above-described vacuum fryer.

  The onion material to be used, the oil to be used, and the temperature of the oil are the same as those in the first embodiment of the method for producing fried products.

  As a preparatory step, the inside of the vacuum chamber 52 is set to 0 to 31.3 kPa (absolute pressure) by a vacuum pump (not shown). Moreover, the oil in the oil tank 54 is heated with a heater (not shown).

  The onion pieces T are supplied from the supply device 58 to the transport conveyor 56 so as not to overlap each other. The onion piece T is conveyed from the upstream side 50a to the downstream side 50b while being positioned between the lower net conveyor belt 62c and the upper net conveyor belt 64c.

  The first frying process unit 74 performs a first frying process in which the onion pieces T are fried in an oil-filled state below the oil level L0.

  Since the upper net conveyor belt 64c travels on the level L1 below the oil level L0, the onion piece T is forcibly submerged below the oil level L0. At this time, the onion piece T is heated by the oil, and the temperature of the oil in the vicinity of the onion piece T decreases. However, since the upper net conveyor belt 64c and the lower net conveyor belt 62c are running, convection occurs in the oil around the onion piece T, and the heat of the hot oil is positively transmitted to each onion piece T, and the onion The moisture of the piece T, particularly the moisture near the cut surface, is evaporated in a short time. Further, since the onion pieces T are supplied so as not to overlap each other, the onion pieces adhere to the upper net conveyor belt 64c due to the sugar content from the onion pieces T, and the onion pieces stick to each other and heat transfer occurs. Prevent non-uniformity.

  In the second frying process unit 76, the onion pieces T are fried in an oil state and the onion pieces T are fried in an oil surface state in which the onion pieces T are floated in the vicinity of the oil surface L0. A second frying process is repeated. It is preferable for the efficient frying operation that the in-oil time in the oil state is longer than the oil surface time in the oil surface state. Specifically, when the upper net conveyor belt 64c is traveling below the oil level L0, the onion piece T is fried in an oil state, and the upper net conveyor belt 64c is above the oil level L0. The onion piece T is fried in the oil level when traveling at the level of. When the onion piece T is fried in an oil level state, the onion piece T is conveyed toward the downstream side 50b by the lower net conveyor belt 62c traveling on the level L3 immediately below the oil level L0.

  The boundary between the first frying process part 74 and the second frying process part 76 is where dehydration proceeds in a part of the translucent onion piece T, and the onion piece T has become partially white. It is preferable that Alternatively, the boundary is preferably determined where the moisture of the onion is 40 to 95%, and more preferably determined where the moisture of the onion is 55 to 65%.

  The operation when the upper net conveyor belt 64c is traveling on the level L1 lower than the oil level L0 is the same as that of the first frying process unit 74.

  When the upper net conveyor belt 64c is traveling on the level L2 above the oil level L0, the onion piece T is in a floating state near the oil level L0, and the heat transfer efficiency from the oil to the onion piece T is Lower than when in the middle state. Thereby, the heating of the surface of the onion piece T is suppressed and the progress of the burning of the surface is suppressed, while the heat in the vicinity of the surface of the onion piece T moves to the inside, and the heating is continuously performed inside the material. As a result, the water | moisture content of the center part of the onion piece T moves toward a cut surface. Since the lower conveyor 62 and the upper conveyor 64 are running, the heat transfer efficiency to each onion piece is uniform.

  In the third frying process unit 78, the time when the onion piece T is fried at the oil level and the onion piece T is fried at the oil level is the time when it is at the oil level. A third fly process is repeated that is alternately repeated at a second pitch P2 shorter than the first pitch P1 so as to be the same as or shorter than the time. The operations of the lower net conveyor belt 62c and the upper net conveyor belt 64c are the same as in the second frying process.

  The boundary between the second frying process and the third frying process is preferably defined where a part of the onion piece T has started to burn. Alternatively, the boundary is preferably defined where the onion moisture is 5 to 40%, and in order to shorten the entire frying time, the onion moisture is determined to be 15 to 25%. More preferably.

  By increasing the ratio of the oil level time to the oil time, the second pitch P2 is made shorter than the first pitch P1, thereby further suppressing the progress of the surface scoring. Moreover, the heat | fever which the onion piece T has has the water | moisture content inside an onion piece T moving to a cut surface part, and the water | moisture content in a part far from a cut surface is evaporated slowly. After the third frying step, the onion water content is preferably 0.5 to 3%. Ultimately, it is possible to significantly reduce defective products in which the onion pieces are scorched or the inside of the onion pieces is raw.

  The onion piece T after frying is dewatered by the deoiler 60.

Next, an experimental example of the above-described vacuum fryer which is the first embodiment of the present invention will be described.
The amount of onion pieces to be put in the frying basket 8 was 2000 g. The water content of the onion pieces was 75%. The oil temperature in the frying container 2 was 80 ° C., and the pressure in the frying container was about 10 kPa (absolute pressure).
The rotation of the fly cage 8 is repeated for 10 seconds for the right rotation, 5 seconds for the rotation stop time, 10 seconds for the left rotation, and 5 seconds for the rotation stop over the first fly step, the second fly step, and the third fly step. It was.
First, the first frying process was performed for 5 minutes. That is, stirring in the oil state was continuously performed for 5 minutes. After the first frying step, the onion moisture content was 60%.
Next, the second frying step was performed for 18 minutes. The first period was 60 seconds, the in-oil time was 50 seconds, and the oil level time was 10 seconds. After the second frying step, the onion pieces contained 20% of water.
Next, the third frying step was performed for 2 minutes, the second period was 20 seconds, the in-oil time was 10 seconds, and the oil level time was 10 seconds. After the third frying step, the water content of the onion pieces became 1.5%.
Finally, the oil was removed at 14 G for 30 seconds using a centrifuge.
The water content of the onion pieces was calculated from the weight after extracting the sample and repeating the drying until reaching a constant weight at 105 ° C. for 3 hours and the weight before drying.

  Table 1 is a table comparing the defective rate of onion fried products manufactured by the conventional method and onion fried products manufactured by the method of the present invention. The “defective product (buku)” in Table 1 refers to a state in which moisture contained in the onion is vaporized and the skin swells like a balloon. As can be seen from Table 1, the defective product rate could be significantly reduced from 40% to 3.1%.

  In addition, the onion fried product obtained by the method according to the present invention, that is, the onion snack has a crispy texture, a sweet flavor peculiar to the onion, a savory roasted feeling, a sweet taste, and a dark color. Compared to the onion snacks obtained, we were able to obtain a product with the taste of the ingredients on the front.

  Further, in the method according to the present invention, the efficiency of heat transfer from the oil to the onion pieces is good. Therefore, the ratio of the weight of the oil to the weight of the material, that is, the oil holding amount is 24 times that of the conventional method. I was able to reduce it twice. Therefore, the amount of the oil sucked and taken out by the material with respect to the weight of the oil, that is, the ratio of the replenishment amount of the oil is increased, the deterioration of the oil is suppressed, and the product quality can be improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims. Needless to say, these are also included within the scope of the present invention.

  In the above embodiment, an onion has been described as an example. It may be a dough. In particular, it is useful for materials in which internal moisture is difficult to move to the dewatered surface portion (including onion materials and other materials that are thick and require heat transfer to the center even if they are covered with a cut surface). However, in the material in which the moisture inside easily moves to the cut surface (dewatered surface), the texture of the fried product produced by the method according to the present invention is more crisp than the fried product produced by the conventional method. Is preferably made into a fried product by the method according to the invention.

  Further, in the first embodiment of the frying product manufacturing method, in the third frying step, stirring in the oil state and stirring in the oil surface state are alternately repeated. The entire car 8 may be raised above the oil level L, and stirring in the oil state and lifting to the air position may be alternately repeated.

1 is a schematic view of a vacuum fryer according to a first embodiment of the present invention with a frying basket in an oil position. 1 is a schematic view of a vacuum fryer according to a first embodiment of the present invention with a fly cage in the oil level position. FIG. 1 is a schematic view of a vacuum fryer according to a first embodiment of the present invention in a state where a fly cage lifts an upper lid of a frying container. It is a schematic front sectional view of a vacuum fryer according to a second embodiment of the present invention. FIG. 5 is a partial side cross-sectional view of an upper conveyor and a lower conveyor of the vacuum fryer of FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum fryer 2 Fry container 6 Heater 8 Fry basket 8a Oil position 8b Oil surface position 50 Vacuum fryer 50a Upstream side 50b Downstream side 54 Oil tank 56 Conveyor conveyor 62c Lower net conveyor belt 64c Upper net conveyor belt 74 First frying process Part 76 second frying process part 78 third frying process part L0 oil level L1 level above oil level L2 level below oil level L3 level P1 immediately below oil level first pitch P2 first Pitch of 2

Claims (7)

A method of manufacturing a fried product from a material with a vacuum fryer,
Putting the material having the cut surface into the top basket, the side surface and the bottom of the fly basket,
A first frying step in which the entire frying basket is submerged in oil and rotated about the vertical axis, and the material is fried in an oil state submerged under the oil level of the vacuum fryer;
After the first frying step, the entire frying basket is submerged in oil and rotated about the vertical axis to fly the material in the oil state, and the frying basket is submerged in half oil and the vertical axis is Rotating in the center and frying the material in the oil surface state floating near the oil surface, a second frying step that alternately repeats in a first cycle;
After the second frying step, the entire fly cage is submerged in oil and rotated about the vertical axis to fly the material in the oil state, and the fly cage is submerged in half oil and the vertical axis is The time in the oil state means that the material is fried in the oil level by rotating it to the center, or the whole basket is raised above the oil level and the material is lifted to an air position above the oil level. And a third fly step that alternately repeats at a second period shorter than the first period so as to be equal to or shorter than the time at the oil level or in the air position. .   The method according to claim 1, wherein the moisture content of the material is 0.5 to 3% after completion of the third frying step.   The method according to claim 1 or 2, wherein when the moisture content of the raw material is 40 to 95%, the first frying step is shifted to the second frying step.   The method according to any one of claims 1 to 3, wherein when the moisture content of the material is 5 to 40%, the process proceeds from the second frying step to the third frying step.   2. The time of the oil level state during the first cycle of the second frying step is the same as the time of the oil level state during the second cycle of the third frying step. The method of any one of -4.   The method according to claim 1, wherein the material is an onion. A vacuum fryer placed in a vacuum chamber,
An oil tank extending from the upstream side to the downstream side;
A conveying conveyor for conveying the material to be fried from the upstream side to the downstream side in the oil tank,
The conveying conveyor has an upper net conveyor belt and a lower net conveyor belt facing each other, and the material is conveyed while being positioned between the upper net conveyor belt and the lower net conveyor belt,
The upper net conveyor belt travels at a level lower than the oil level downstream of the first frying process unit that travels below the oil level in the oil tank and the first frying process unit. And a second fly process unit that repeatedly repeats at a first pitch, and a lower level than the oil level, downstream of the second fly process unit. Driving a level and driving a level above the oil level, the distance traveled below the oil level is equal to or greater than the distance traveling the level above the oil level A vacuum fryer characterized by having a third frying process section that repeats alternately at a second pitch shorter than the first pitch so as to be shorter.

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