JPS6057826B2 - How to peel chestnuts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention reduces the yield of chestnut pulp, increases the peeling rate, allows peeling without damaging the yield-like surface just below the astringent skin, and allows The object of the present invention is to provide a method for peeling chestnuts, which allows peeled chestnuts with a very small cracking rate to be obtained.

Traditionally, chestnuts are placed in an airtight container filled with steam at a constant pressure, and the chestnuts are heated to the depths that are not affected by the heat.
After heating for a short time, the chestnuts are rapidly released from the airtight container into a buffer under atmospheric pressure to peel off the bitter skin and astringent skin, and then, after removing the peeled astringent skin and bitter skin, the chestnuts are rubbed together and washed. Method for peeling chestnuts
However, in this method, if the pressure or temperature of pressurizing and heating the chestnuts is increased or the time is kept for a long time in order to increase the peeling rate, the yield of peeled chestnuts decreases. On the other hand, if the pressure or temperature of chestnuts is lowered or kept for a shorter time in order to improve the yield, the peeling rate will decrease and the proportion of chestnuts that must be peeled later by hand will increase. It has the disadvantage of reduced efficiency.

Furthermore, unlike European chestnuts, Japanese chestnuts have an astringent skin attached to the flesh side, so the above-mentioned known method cannot produce peeled chestnuts with a yield-like surface like those used for marron glace. It has the disadvantage of being difficult.

As a result of various studies, the inventors of the present invention found that chestnuts were placed in an airtight container, heated under pressure with water vapor, etc., and then instantly released into a buffer under normal pressure. It was discovered that spraying on chestnuts significantly improves the peeling rate without reducing the yield of chestnuts, resulting in peeled chestnuts with a yield-like surface.Based on this, the present invention was completed.

The present invention will be explained in detail below.

In the present invention, chestnuts are first placed in a sealed container, heated under pressure using saturated steam, superheated steam, or high-pressure heated gas, and then instantly released into a buffer under normal pressure to remove all of the chestnut skin and part of the astringent skin. peel off the skin.

The apparatus used here may be either a batch type or a continuous type. Batch type devices include devices in which the contents are placed in a closed container, the container is heated under pressure with pressurized heating gas, and then the pressure is rapidly released; continuous type devices include, for example, the device shown in Figure 1. Chestnuts to be peeled are fed into the rotary rotary tube from the raw material introduction part 3 of a hollow airtight container 2, which is equipped with a screw conveyor 1 as shown in FIG. The chestnuts are continuously introduced into the closed container 2 in an airtight manner through the valve 4, and are continuously pressurized and heated while being moved.Then, the heated chestnuts are continuously discharged from the raw material outlet 6 into the rotary pulp. 7, an apparatus for producing puffed foods as described in Japanese Patent Publication No. 45-26695, Japanese Patent Publication No. 52-1
A pressurized continuous steaming apparatus as described in Publication No. 997,
and a continuous steaming and puffing apparatus for food raw materials as described in Japanese Patent Publication No. 49-154. still,
In FIG. 1, 8 is a hopper that holds chestnuts, 9 is a packet elevator that quantitatively supplies the chestnuts to the raw material introduction section 3, and 10 is a part of the steam that is discharged from the input rotary valve 4 and the discharge rotary valve 7. Also, since steam is discharged from the steam exhaust hole 35 of the astringent peeling device 14, which will be described later, this is a blower that forcibly discharges the steam to the outside. The liquid is introduced into the airtight container. Examples of the gas used for pressurizing and heating chestnuts include saturated steam, superheated steam, heated carbon dioxide gas, nitrogen gas, and alcohol vapor, with saturated steam being particularly preferred. The conditions for pressurizing and heating vary depending on the size, type, freshness, and storage method of the chestnuts, but usually the gauge pressure is 3~10k9/
Cltl is particularly preferably 4-8k9/d, and the temperature is 143-8k9/d.
183lC1, particularly preferably 151 to 174°C.

Further, the time is preferably 20 to 2008, particularly 30 to 12. The relationship between temperature and time under the above pressurized heating conditions is inversely proportional; it is preferable to shorten the time when the temperature is high and to lengthen the time when the temperature is low. For example, when using saturated steam, 4k9/CFl [1008
, 8 fish in 5k9/C7lf, 6kg/d in seconds, 7k9
/C7l! It is preferable to set the speed at 5 hoe and 8k9/d at around 10 seconds. In addition, the pressure and time conditions for the above-mentioned pressurized heating are such that chestnuts are changed from high pressure to low pressure. It is preferable to set the pressure and time conditions such that the rate of exfoliation of the bitter skin is 100% and the rate of peeling of the astringent skin is 50% or less when rapidly released.
Processing under these conditions hardly prevents the softening of the pulp, which is followed by the removal of the skin. In the operation and peeling operation, damage and loss of the pulp can be prevented as much as possible, the yield is significantly improved, and peeled chestnuts with a clean wrinkled surface can be obtained. The chestnuts heated under pressure in this manner are instantaneously discharged into a buffer under normal pressure. The shock absorber used here may be of any kind as long as it can absorb the impact of the chestnuts being released with a rapid force along with the steam, for example, the impact of the chestnuts being released via the discharge rotary valve 7. A device in which a shock absorbing plate such as a sponge is provided diagonally above the passage so as to block the passage, and the shock absorbing plate is surrounded by a rubber sheet or the like, or as shown in Fig. 1. Examples include the water tank 11. By providing such a shock absorbing device, it is possible to prevent the chestnuts from being crushed into small pieces even if the speed of the chestnuts when they are discharged from pressurized to atmospheric pressure is quite high. After the skin of the chestnuts obtained in this way is completely separated and removed, the astringent skin adhering to the surface of the chestnut is separated and removed by spraying high-speed steam such as saturated steam or superheated steam.

The skin removal operation described above may be performed manually, but in order to do this efficiently, as shown in FIG. The upper end opening is used as an input port 13, the lower end opening is used as a peeled chestnut discharge port, and a gas ejection hole 15 is opened in the bottom wall halfway through the guide plate 12, facing the gas ejection hole. An example of this device is a device in which a skin discharge port is opened in the upper wall of the device, and the lower end of the gas jet hole 15 is connected to an air inlet of a gas supply device 16 such as a blower. Next, the chestnuts from which the skin has been completely separated are sprayed with high-speed steam to completely separate and remove the astringent skin adhering to the surface of the chestnuts.

The astringent skin peeling device used here may be any device that can spray high-speed steam onto chestnuts to remove the astringent skin remaining on the surface of the chestnuts. For example, Examples include devices as shown in FIGS. 2 and 3.

FIG. 2 is a schematic longitudinal cross-sectional view of the astringent peeling device 14 of FIG. 1;
FIG. 3 is an enlarged three-dimensional sectional view of the main part of the device. This device includes a substantially box-shaped hollow container 23 having a raw material input port 21 and a peeled chestnut discharge port 22, and a discharge port 2 from the input port 21.
a bottom plate 25 having a high-speed steam outlet 24 stretched up to 2; a scraping plate 26 located above the bottom plate 25 for transporting chestnuts from the input side to the discharge side; and a chain 2 for driving the scraping plate.
7 and a sprocket 28, etc., and a drive device provided through a slight gap from both ends of the scraper plate.
The structure includes a top plate 31 having an astringent skin discharge hole 30 and a steam communication pipe 32 connected to the high speed steam ejection hole 24. In this astringent skin peeling device, the astringent skin discharge hole 30 provided in the top plate 31 is smaller than the chestnut pulp that is the raw material;
It may have a diameter larger than that of the astringent skin; for example, in the case of chestnuts from which the astringent skin has been separated after high-pressure heat treatment, the diameter is usually 6 to 10 w.
n is also sufficient.

In addition, the diameter and steam pressure of the high-speed steam outlet 24 allow the chestnuts to be properly exposed to steam and rotate inside the box without colliding strongly with the top plate in the box consisting of the scraper plate 26, side plate 29, and top plate 31. For example, the diameter of the high-velocity steam nozzle should be 2 to 3 m, and the steam pressure should be 1 to 3 k9/Cri-
It is preferable to set it as G.

Further, as shown in FIG. 2, if necessary, a water sprinkling pipe 33 is provided between the top wall of the hollow container 23 and the top plate 31, and water is projected onto the inner wall of the hollow container and the top surface of the top plate 31. The astringent skin adhering to the top surface of the top plate can be effectively washed and removed.

Further, as shown in FIG. 2, a water withdrawal pipe 34 is provided above the bottom plate 25 near the peeled chestnut discharge port 22, and water is withdrawn from the water sprinkling pipe to thoroughly wash off the astringent skin that slightly adheres to the surface of the chestnuts. I can do it.

Note that 35 is a steam exhaust hole that communicates with the blower 10 described above. Further, 36 is a drainage hole, and 17 to 19 are conveyors. In this way, chestnut pulp from which the astringent skin has been completely peeled is obtained.

Since the present invention has the above configuration, it is possible to improve the peeling rate without reducing the yield of chestnut pulp, and to cleanly peel the astringent skin without damaging the wrinkled layer on the surface of the pulp immediately below the astringent skin. I can do it.

Moreover, peeled chestnuts with a very low cracking rate can be obtained even when boiled in water. Hereinafter, the present invention will be explained in more detail by showing examples.

Example: Remove rotten and damaged chestnuts and prepare five 100 kg large chestnuts (variety: Ginyose) with uniform grains.
When chestnuts from each category were peeled using a chestnut peeling device as shown in FIG. 1, the results shown in Table 1 were obtained.

That is, the raw chestnuts of the first to fifth categories are placed in a sealed container 2, heated under pressure using saturated steam under the pressure heating conditions listed in Table 1, and then momentarily released into a water tank 11 under normal pressure. It was taken out from the bottom of the water tank 11 using a net conveyor 37.

The chestnuts thus obtained are fed into the inlet 13 of the skin removal device 38 and flowed down the elongated cylindrical guide path for moving the chestnuts to the gas jet hole 15 provided in the bottom wall midway through the guide plate 12. The skin is separated from the fruit pulp by scattering the skin outside from the skin discharge port by the gas ejected from the pulp, and the fruit pulp is collected from the pulp discharge port to remove the skin, but the astringent skin is Obtain peeled chestnuts that can be attached in large quantities.

Next, the peeled chestnuts with astringent skins obtained in this way are
The raw material is inputted from the raw material input port 21 of the astringent skin peeling device 14, and is partitioned into many sections by scraping plates 26 in a cylinder consisting of a bottom plate 25, side plates 29, and top plate 31, and is transferred in the cylinder while being transported. High-speed steam ejects from the bottom to the top (diameter of steam ejection pipe 2.5?, steam pressure 2k9/d・G)
), the astringent skin adhering to the surface of the chestnut is blown away or peeled off and separated from the pulp, and is transferred to the top plate 31 along with the steam.
The astringent skin is discharged from the astringent skin discharge hole 30.

The astringent skin can be peeled with high efficiency even when high-speed steam is sprayed on the peeled chestnuts using raw chestnuts with the astringent skin removed by hand peeling or peeled chestnuts with the astringent skin removed from the raw chestnut using flame. However, when raw chestnuts are heated under pressure and then the pressure is suddenly released to remove the outer skin, as described above, when high-speed steam is sprayed on the chestnuts, the astringent skin can be peeled off from the pulp very easily. I can do it. The reason is,
This is believed to be because when chestnuts are heated under pressure and then rapidly released, the astringent skin swells and floats above the pulp, making it easy to peel off due to collision with high-speed water vapor. In this way, the chestnuts from which the astringent skins have been peeled receive water projected from the drainage pipe 34 provided above the bottom plate 25 near the peeled chestnut outlet 22, and the astringent skins adhering to the surface of the chestnuts are washed away. , peeled chestnuts as described in Table 1 are obtained.

On the other hand, for comparison, chestnuts obtained according to the embodiment of the method for peeling chestnuts of JP-A-54-119077, that is, chestnuts, were placed in a sealed container 22, heated under pressure under the conditions listed in Table 1, and then rapidly The chestnuts obtained by discharging the chestnuts into a water tank 11 under normal pressure, removing the astringent skin and the bitter skin, and then washing the chestnuts by rubbing them together are described.

In Table 1, the 1-peeling rate Jr. yield and the 1-time boiling cracking rate were obtained based on the following calculation formulas, respectively.

However, the number of peeled chestnuts after treatment is the number of peeled chestnuts whose astringent skin has been completely removed.

In addition, the cracking rate during boiling is the percentage of chestnuts that are broken when peeled chestnuts with their astringent skins completely removed are boiled in water using the boiling method shown below.

<How to boil in water> Place chestnuts and water in a steam-heated double pot, gradually raise the water temperature to 65℃ for about 3 minutes, and hold at that temperature for about 4 hours.

Next, discard the hot water, add new water, gradually raise the water temperature to 95℃ for about 4 minutes, hold it at 95-9rC for 3 hours, then turn off the heating steam and slowly cool it until it reaches about 100℃. Leave it for a while,
Next, gently take out the chestnuts to obtain boiled peeled chestnuts.
From this result, as shown in categories 5 and 7, when the peeling rate is increased to 100% in the comparative example, the final yield is 41.
If you try to increase the yield to 52.5% and 50.5% like in categories 6 and 8, you have to lower the peeling rate to 86% and 90%, respectively. .

On the other hand, the present invention can obtain a final yield of almost 70%, which is close to the limit, and a peeling rate of 92% or more, and furthermore, it is possible to obtain peeled chestnuts with a wrinkled surface. is obtained. Furthermore, it can be seen that the effect that the cracking rate when boiled in water is significantly lower than that of the comparative example can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing a chestnut peeling apparatus for carrying out the method of the present invention, FIG. 2 is a longitudinal cross-sectional schematic explanatory diagram of the astringent peeling apparatus of FIG. 1, and FIG. 3 is the main part of FIG. 2. It is an enlarged three-dimensional sectional view. 1... Screw conveyor, 2... Sealed container, 3... Raw material introduction section, 4... Input rotary valve, 5... Steam Communication pipe, 6.
... Raw material discharge port, 7 ... Discharge port rotary valve, 8 ... Hopper, 9 ... Packet elevator, 10 ... Blower, 11 ...
...Aquarium, 12...Guidance board for moving chestnuts, 1
3...Input port, 14...Astringent peeling device, 15
...... Gas blowout hole, 16... Gas supply device, 17-19... Conveyor, 21... Raw material inlet, 22... Peeled chestnut outlet, 23...
Hollow container, 24... High speed steam outlet, 25...
...Bottom plate, 26...Kaki board, 27...
Chain, 28...Sprocket, 29...
・Side plate, 30...Astringent skin discharge hole, 31...
・Top plate, 32... Steam communication pipe, 33, 34...
...Water pipe, 35...Steam exhaust hole, 36...
・Drain hole.

Claims (1)

[Claims] 1 Chestnuts are placed in an airtight container, heated under pressure with steam or other gas, and then momentarily released into a buffer under normal pressure. A method for peeling chestnuts characterized by separating and removing the skin of chestnuts.