JPS6126331B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing packaged peeled chestnuts, and particularly to a method for producing packaged peeled chestnuts that have a non-sticky surface, a strong aroma and sweetness unique to chestnuts, a deep yellow color, and a good appearance. In general, packaged peeled chestnuts have a non-sticky surface, are rich in the unique flavor of chestnuts, are deep yellow in color, have a good appearance, and have a good texture, so they can be used as is as an ingredient in dishes and confectionery. It is required to have characteristics such as being able to be stored for a long period of time. Previously, some of the inventors of the present invention proposed a method for producing packaged peeled chestnuts by placing chestnuts in a sealed container, heating them under pressure with high-temperature gas, and then instantly releasing them into a buffer device under normal pressure to peel them. He invented a method of massaging and washing raw peeled chestnuts, placing them in a heat-resistant and water-resistant packaging container, sealing them, and heating them under pressure, and applied for a patent.
57−52036). Through this method, we can unwrap the chestnuts, which have a beautiful shape unique to chestnuts, a flavor unique to chestnuts, a pale yellow color, a good texture, and can be used directly as an ingredient in dishes and confectionery. I got chestnuts. However, when we carefully investigated the characteristics of the packaged and peeled chestnuts obtained in this way, we found that the surface of the chestnuts was sticky, and although the chestnuts had a characteristic aroma, they were weak, the taste was a bit watery, and the color tone was unappealing. I learned that it has some problems. Another method is to place the chestnuts in a rotating cylinder heated by a burner, first char the skin and astringent skin, then lower the heating temperature of the burner and steam-roast them, and then blow the charred skin and astringent skin with high-pressure air. A method of separating and obtaining half-roasted peeled chestnuts, placing them in a heat-resistant and water-resistant packaging container, and heating them under pressure.
5386) is also known, but with this method, the peeled chestnuts obtained have the characteristic burnt odor and taste of roasted chestnuts, are brown in color, look bad, and are quite hard, so they cannot be used as is for cooking or confectionery. It has a major drawback in that it cannot be suitably used as a material for. Therefore, the present inventors conducted various studies in order to obtain packaged peeled chestnuts that do not have the above-mentioned problems and drawbacks, and as a result, we have developed a heat-resistant When the chestnuts were placed in a water-resistant packaging container, sealed and heated, the surface of the chestnuts did not become sticky.
Peeled chestnuts with a deep yellow color tone can be obtained, and if the above-mentioned method of drying by contacting with heated gas is used, the unique aroma of chestnuts will be very strong, and the sweetness unique to chestnuts will also be very strong, resulting in a strong umami flavor. It was discovered that peeled chestnuts can be obtained, and the present invention was completed based on this knowledge. In other words, the present invention uses raw peeled chestnuts at 1.5 to 9.0%.
(W/W) After drying, the packaged peeled chestnuts are placed in a heat-resistant and water-resistant packaging container, sealed, and then heated. This is a method for producing packaged peeled chestnuts, which is characterized in that after being brought into contact and dried 1.5 to 9.0% (W/W), the chestnuts are placed in a heat-resistant and water-resistant packaging container, sealed, and then heated. The present invention will be explained in detail below. The raw chestnuts used in the present invention can be peeled using a conventional chestnut peeling device (for example, Japanese Patent Publication No. 57-11628).
Alternatively, raw peeled chestnuts obtained by removing the skin and astringent skin of chestnuts by hand may be mentioned. If these raw peeled chestnuts have water attached to their surface due to rubbing or washing with water, it is preferable to thoroughly drain the water to remove the water from the surface. In the present invention, drying of raw peeled chestnuts is carried out until the ratio of "weight of peeled chestnuts after drying" to "weight of peeled chestnuts before drying" decreases by 1.5 to 9.0% (W/W). This drying step in the present invention is extremely important, and if the drying rate is less than 1.5%, it will not be possible to eliminate the stickiness that occurs on the surface of the packaged peeled chestnuts, and it will be difficult to obtain packaged peeled chestnuts with a deep yellow color and good appearance. I can't. On the other hand, if the drying rate exceeds 9.0%, the color of the packaged peeled chestnuts will change to light brown, and the hardness will increase, resulting in poor texture, which is not preferable. On the other hand, when the drying rate is 1.5 to 9.0%, the stickiness that occurs on the surface of the packaged peeled chestnuts is completely eliminated, and the packaged peeled chestnuts have a deep yellow color, good appearance, and a very good texture. can get. There are no particular restrictions on the method of drying raw peeled chestnuts, as long as the method does not change the quality of the peeled chestnuts, such as browning or scorching them, such as natural drying, compression, etc. Examples include an air drying method, a reduced pressure drying method, a dry heat drying method, a hot air drying method, and a superheated steam drying method. When using a drying method that involves contact with heated gas, drying is not only efficient, but this drying method surprisingly intensifies the unique aroma of chestnuts, and also increases the sweetness of the chestnuts, making them delicious and delicious. I discovered that it can be done. In particular, the superheated steam drying method is preferable because it can be dried in a much shorter time than other drying methods and with less loss of quality. In the drying method in which the peeled chestnuts are brought into contact with heated gas, it is particularly important to carry out the drying under such conditions that the temperature of the peeled chestnuts is maintained within the range of 60 to 90°C. i.e. 60℃
If the drying time is less than that, the drying time will be longer and the effect of enhancing the chestnut-specific aroma and sweetness will not be so great. On the other hand, if the temperature exceeds 90°C, the surface of the peeled chestnuts will be thermally denatured, resulting in a loss of quality and increasing the risk of browning, which is not preferable. On the other hand, when the temperature is maintained at 60 to 90°C, particularly 70 to 80°C, the quality of the chestnuts is not impaired, and extremely good packaged peeled chestnuts with a strong chestnut-specific aroma and a strong sweetness can be obtained. Example 1 Approximately 50 g of raw peeled chestnuts obtained by hand peeling was taken and cut into fine pieces, divided into multiple sections of 5 g each, and after homogenization by adding water or hot water to each section, the total volume was made up to 90 ml. 50, 60, 70, 80,
The solution was maintained at 90 and 100°C for 60 minutes, then heated at 100°C for 15 minutes, filled up to 100 ml, and stirred well. The amount of glucose in the solution was measured using a conventional method, and the results shown in Table 1 were obtained. It was done. From this result, the amount of glucose produced in the category where chestnuts are kept at 60 to 90°C is 5.2 to 9.6 mg/g, which is significantly higher than the 3.0 to 3.6 mg/g in the category where the chestnuts are kept at temperatures other than the above. It can be seen that the sweetness of chestnuts increases.

[Table] Next, the raw peeled chestnuts that have been properly dried in this manner are weighed in predetermined amounts and placed in a heat-resistant and water-resistant packaging container, and the opening is sealed and heated. The heat-resistant and water-resistant packaging container used here may be of any kind as long as it has both heat resistance and water resistance, such as plastics such as nylon, polyethylene, polyester, polyolefin, polypropylene, etc. It may be laminated or laminated with aluminum foil, and may be in the form of a bag or a packaging container. It may also be a packaging can made of tin or aluminum. Next, the method of sealing the peeled chestnuts after placing them in these heat-resistant and water-resistant packaging containers may be simple sealing, vacuum sealing, nitrogen or carbon dioxide gas displacement sealing, etc.; The method of sealing the chestnuts by leaving a head space in the container results in poor heat conduction to the chestnuts packed in the packaging container during the next heating process, requiring long heating times, and causing uneven steaming of the chestnuts. Therefore, a vacuum sealing method is particularly preferable, in which deaeration is performed prior to heat treatment to almost completely eliminate the space between chestnuts. The sealed package is then heated. The heating device used here may be any device that can heat a packaging container filled with peeled chestnuts for a certain period of time under pressure or normal pressure. Examples include a device that can place chestnuts in a closed container, pressurize and heat the container with high-pressure heating gas, and then gradually release the pressure, and a device that can boil a packaging container filled with peeled chestnuts under pressure. Examples of the high-pressure heating gas used in the pressurized heating device include heated air, saturated steam, superheated steam, and the like, with saturated steam being preferred. Next, the heating conditions for the peeled chestnuts sealed in the packaging container are: either the peeled chestnuts are packaged by heating and sterilized only on the surface and the inside remains raw, or the packaged chestnuts are packaged and steamed, which heat-denatures the inside as well as the surface. Should it be chestnuts?
It varies depending on the form of the product, as well as the type of packaging container, the material of the packaging container, the thickness of the packaging container, the head space of the packaging container, the particle size of the peeled chestnuts, and the desired hardness of the chestnuts. However, the pressure and heating may be continued until the chestnuts reach the desired product form or softness. For example, if you want to obtain chestnuts as soft as boiled chestnuts by placing raw peeled chestnuts in a plastic film bag and vacuum-sealing them, you would normally place them in a pressure-heated steamer and use saturated steam to heat them. In this case, the pressure should be the gauge pressure.
0.5-3 Kg/cm ² , particularly 1-2 Kg/cm ² is preferred, and the temperature is preferably 110-143°C, especially 120-133°C. Moreover, the time is preferably 5 to 30 minutes, particularly 10 to 20 minutes. The relationship between temperature and time under the above pressure heating conditions is inversely proportional; when the temperature is high, the time is shortened;
When the temperature is low, it is preferable to increase the time, for example, 15 minutes at a gauge pressure of 1Kg/ ^cm2 , and 1.5Kg/ ^cm2 at a gauge pressure of 1Kg/cm2.
13 minutes and around 10 minutes at 2Kg/cm ² is suitable. If you want to obtain steamed chestnuts that are softer than usual, the above-mentioned pressure and heating conditions may be applied harshly, and on the other hand, if you want to obtain harder steamed chestnuts, you may perform the heating conditions more gently. In this way, packaged peeled chestnuts having the desired shape, desired softness, or hardness are obtained. The thus obtained product of the present invention is a packaged peeled chestnut that has no stickiness on the surface of the chestnut, has a deep yellow color and looks good, and has a very strong aroma and sweetness unique to chestnuts. Chestnuts differ from other vegetables and fruits in that they not only have a unique shape but also a unique aroma and sweet taste.
In addition to being eaten as a dish, it is also used as an ingredient in dishes such as ``Kamameshi'' and ``Chestnut Okowa'', as well as Japanese sweets such as ``Kuri Yokan'' and ``Kurimonaka'', ``Marron Glace'', and ``Marron Cake''.
It is used in many dishes and foods, such as Western sweets, and is enjoyed by many people. Therefore, it is important to enhance the aroma and sweetness of packaged peeled chestnuts, which are suitably used as ingredients for many dishes and foods, and to make them look good by changing the color tone to deep yellow. , has extremely great significance in increasing the commercial value of food products. The present invention will be explained in more detail below using Examples. Example 1 3 kg of raw chestnuts were placed in a puffing gun with a capacity of 5 and heated over an open flame while rotating the container until the internal gauge pressure reached 6 kg/cm ² and the temperature reached 164°C.
After holding for 130 seconds, suddenly open the outlet,
Put the chestnuts into a water tank under normal pressure, peel off the skin and astringent skin, take out only the pulp from the water, transfer it to another container, wash it by gently rubbing it with your hands under water for 3 minutes, and drain it completely. 2 kg of raw peeled chestnuts
I got it. Next, the raw peeled chestnuts obtained in this way are divided into many sections and dried using a normal compressed air drying method to achieve a drying rate of 1.0, 1.5, 3.0, 5.0, and 9.0.
and 10.0% (W/W) dried peeled chestnuts were obtained. Next, weigh approximately 150g each and make a 13cm x
Pack into a retort pouch (RP-F ₁ , Toyo Seikan Co., Ltd.) laminated with 17 cm of aluminum foil and vacuum seal. Next, the bag filled with chestnuts was placed in an autoclave with a water spray nozzle inside, and heated under pressure with saturated steam (temperature 121℃) at a gauge pressure of 1 Kg/cm ² for 15 minutes. Pressure 1
The air was replaced with Kg/cm ² of air, and then water was sprayed from a water spray nozzle to cool it for 1 minute, and the pressure was returned to normal pressure to obtain packaged peeled chestnuts. For comparison, control packaged peeled chestnuts were obtained in exactly the same manner as described above, except that the raw peeled chestnuts were not dried. As a result of examining the "stickiness", "color tone", "hardness" and "texture" of the various packaged peeled chestnuts thus obtained, the results shown in Table 2 were obtained. In the above method, Category 1 with a drying rate of 1% and Category 6 with a drying rate of 10% are comparative examples. Also, the symbol in the "sticky" column of Table 2,
+ indicates sticky, ± indicates slightly sticky, and - indicates not sticky. Evaluations in the "Color tone" column are based on the "Color Standard" published by Nippon Shokusha Co., Ltd. on January 1, 1960. The values in the "Hardness" column indicate values measured using a rheometer manufactured by Fujirica Kogyo Co., Ltd., and the symbol - in the "Texture" column indicates "Bad." ± indicates fair, + indicates good, and ++ indicates very good.

[Table] From the results in Table 2 above, it can be seen that the control category without drying and the category 1 (comparative example) where the drying rate is too low at 1% even if drying is done. The color tone is pale yellow and does not look good, and on the contrary, the drying rate is too high at 10% in Category 6 (comparative example), the color tone turns brown and becomes light brown, and the hardness is 700, compared to the hardness of 350 in the control category. The texture is twice as hard as that of the previous one, indicating that the overall texture is hard and bad. On the other hand, categories 2 to 5 of the present invention with a drying rate of 1.5 to 9.0% are not sticky, have a deep yellow color and look good, have moderate hardness, and have a very good texture. I understand. Example 2 2 kg of raw peeled chestnuts were obtained in the same manner as in Example 1, and divided into a number of equal amounts of chestnuts. Place the chestnuts in a heat dryer until the temperature near the surface reaches
Drying was carried out while maintaining the temperature at 50, 60, 70, 80, 90 and 100°C to obtain dried peeled chestnuts with a drying rate of 3%. Then, in the same manner as in Example 1, the chestnuts were placed in a retort pouch and heated under pressure to obtain packaged peeled chestnuts. For comparison, packaged peeled chestnuts as a control were obtained in exactly the same manner as above except that the raw peeled chestnuts were not dried. The “fragrance” of packaged and peeled chestnuts obtained in this way
A sensory test was conducted on the strength of sweetness and the results shown in Table 3 were obtained. In addition, the sensory test was conducted using a scoring method, and categories 1-
The packaged peeled chestnuts of No. 7 were compared with those of the control category, and evaluated as 0 for no difference, 1 for slightly better, and 2 for good. In addition, the scores in the table represent the average values of 20 trained panelists with discrimination ability. Furthermore, the symbols in the test column mean *: significant difference at 5% risk, **: significant difference at 1% risk, and -: no significant difference. From the results in Table 3, it can be seen that in Category 1, in which raw peeled chestnuts are dried by blowing compressed dry air at 20℃, there is not much of an enhancement effect on the unique aroma and sweetness of chestnuts, but when peeled chestnuts are dried in a dry heat dryer, In categories 2 to 7, which are dried by drying the chestnuts by contacting them with heated air, the effect of enhancing the unique aroma and sweetness of chestnuts was observed, and especially the temperature of chestnuts was
It can be seen that the effect is remarkable when drying is maintained at 60 to 90°C.

【table】

Claims (1)

[Scope of Claims] 1. Production of packaged peeled chestnuts, characterized in that raw peeled chestnuts are dried 1.5 to 9.0% (W/W), placed in a heat-resistant and water-resistant packaging container, sealed, and then heated. Law. 2. Bring raw peeled chestnuts into contact with heated gas to a temperature of 1.5 to 9.0.
% (W/W) A method for producing packaged peeled chestnuts, which comprises drying them, placing them in a heat-resistant and water-resistant packaging container, sealing them, and then heating them. 3. The manufacturing method according to claim 2, wherein the peeled chestnuts are dried at a temperature of 60 to 90°C. 4. The manufacturing method according to claim 2, wherein the heating gas is superheated steam.