JPH0347822B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing dried persimmons that achieves stable quality, omits drying work, and shortens the drying period. [Conventional technology] Conventionally, in the production of dried persimmons, raw persimmons are generally peeled, and then one end of the thread is tied to the fruit stalk, thereby tying multiple raw persimmons together with a thread and hanging them from a bamboo pole. For example, a method is used in which the material is hung in a well-ventilated place, such as in a glass greenhouse, dried in the sun for about 20 days, and then finished by drying with charcoal briquettes or electricity for about 7 days. The conventional dried persimmon production method described above not only requires a long time of 25 to 30 days, but also because the drying conditions such as temperature, humidity, wind speed, etc. vary greatly depending on the weather, so the drying state of the persimmons depends on the drying conditions at that time. It is affected by weather conditions, and the quality and shipping time of dried persimmons fluctuate accordingly. For example, the time to dry fresh persimmons is usually from November to December.
However, in years when the temperature is high and there is a lot of rain at that time of year, there are many rotten fruits, fallen fruits, and mold.
The quality and yield of dried persimmons are significantly reduced. On the other hand, in years when the temperature is low, the after-ripening effect of persimmons does not progress sufficiently, resulting in poor removal of astringency, and astringency remains in dried persimmons. In addition, in this case, the color of the dried persimmons is not constant, and instead of the amber color that is considered an excellent product, the fruit becomes yellow-orange, resulting in a significant deterioration in quality. On the other hand, some drying methods have been implemented in which fresh persimmons are peeled and then stored in an air flow dryer equipped with a dehumidifier and a heater. In this case, the temperature, humidity, wind direction, and flow velocity distribution of the air at the drying air supply port of this dryer may be inappropriate or poorly controlled, resulting in a high initial drying rate and The surface of dried persimmons hardens, making it difficult for the moisture inside to evaporate, and the quality of dried persimmon products often deteriorates, with the fruit turning dark or yellow-orange overall. In addition, because the drying speed becomes excessive, continuous drying cannot be performed, and a period of rest is required in the middle of the drying process.
There were also problems in that the work was cumbersome and efficiency decreased. [Problems to be solved by the invention] As mentioned above, in conventional solar drying, drying of persimmons is greatly influenced by natural conditions, and as a result, the quality of dried persimmons is not stable, and the drying time is extremely long, resulting in low efficiency. It was. On the other hand, even with the conventional method of producing dried persimmons using a dryer, the quality deteriorates, the drying work is complicated, and the work efficiency is not necessarily good. An object of the present invention is to overcome the above-mentioned problems and provide a method for producing dried persimmons that can improve the quality, uniformity, and yield of dried persimmons, save labor, and shorten the drying period. It is. [Means for Solving the Problems] The present invention, which solves the above problems, stores a large number of raw persimmons after peeling in a drying chamber with the fruit bottom facing up,
In the method for producing dried persimmons, the drying air flow is caused to flow into the drying chamber from a supply port to dry the raw persimmons, and the temperature of the drying air flow at the supply port is set to 22 to 22°C.
30℃, relative temperature 40-85%, average flow rate 0.2
~1.0 m/sec, the flow direction of the drying air flow in the drying chamber is directed upward, and the fresh persimmons are dried to remove initial astringency in the drying air flow. [Function] As described above, the present invention performs the initial astringency removal drying of fresh persimmons in an air flow in which the temperature, humidity, and wind speed are controlled within a certain range, and the flow direction is directed upward. However, this was discovered by the inventors as a result of research and experiments. In the present invention, raw persimmons after peeling are placed in an air stream so that they do not come into contact with each other. The raw persimmons to be dried are generally simply hung in pairs tied together with strings placed within the drying chamber. In the drying room, the temperature of the air,
Air with controlled humidity and wind speed (air volume) is sent from a separate room through the supply port. The temperature and humidity control range at the supply port is 22 to 30
℃, 40-85%, and set according to the ripeness of raw persimmons. For example, in the case of Sanjagaki, the ripeness of raw persimmons is classified into three levels according to fruit color and hardness as shown below, and temperature and humidity are controlled according to each ripeness level.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. Example This example is based on a combination of the method described herein and briquette drying using Sanja persimmons. As shown in FIG. 2, 2,500 raw persimmons 6 after peeling are tied together two by two with strings 5, and are placed in a five-tiered bamboo rod holder 3a installed on a drying trolley 1 having wheels 4 as shown in FIG. 27 bamboo poles per each pole on bamboo poles 2 with nine poles arranged on each tier of ~3e.
~28 sets, or 54 to 56 fresh persimmons, were installed. The fresh persimmons attached to the bamboo poles were arranged so that they did not touch each other. Figure 3 shows the fresh persimmons attached to these three drying carts.
Initial astringency removal drying was carried out by the method of the present invention using a drying apparatus 7 having a three-chamber structure shown in FIG. This drying device 7 is connected to a hot air heater 1 by a machine room partition wall 8.
The drying room 7a is divided into two parts: a machine room 7a in which an air conditioner, an air conditioner 12, and a fan 11 are installed, and a drying room 7b in which a drying cart 1 is installed. The drying chamber 7b is further divided into three by drying partition walls 9a to 9b. One drying cart 1 was placed in each room, and the air in the machine room was adjusted to a temperature of 30° C. and a relative humidity of 70% using a hot air heater and an air conditioner, and then supplied to the drying room by a fan 11. The air was an upward flow blown out from the floor of the drying room and discharged from the ceiling, and was controlled at an average wind speed of 0.4 m/sec. Raw persimmons in this drying room are (weight after drying ÷ weight before drying)
Dry until the percentage becomes ×100, that is, the dry weight ratio is 65%, and then dry the dry weight ratio by drying with charcoal briquettes.
The product was shipped at around 30%. Further, this example was conducted at the same time as Comparative Example 1, and the weather during drying was the same as Comparative Example 1. In the figure, 13 indicates a cooler attached to the air conditioner, 14 indicates a duct rectifying plate, and 15 indicates a rectifying plate. Figure 5 shows the dry weight ratio of fresh persimmons to the number of drying days. Here, the solid line shows the initial astringency removal drying by the method of the present invention, and the broken line shows the change in dry weight ratio with respect to the number of drying days when briquette drying is performed subsequent to the method of the present invention. Astringency removal is completed at a dry weight ratio of 65%, and in the method of the present invention, it is completed in 3 days, as seen in Figure 5. In addition, heating to 30°C promotes the after-ripening effect, and the time required for the fruit color (RHS), which is an indicator of the progress of the after-ripening effect, to reach 28-A, is 3 days after the start of drying. It was hot. Moreover,
After drying starts, where there is a high risk of mold growth using conventional methods.
No mold growth was observed even after 48 to 60 hours had passed. Note that no drying work was performed for 3 days after the start of drying. In the subsequent drying of the briquettes, the briquettes were dried at 25°C for 20 hours, then rest-dried for 12 hours, and further dried at 25°C for 20 hours to give a dry weight ratio of 45%. At this point, knead with your hands, leave for 24 hours, dry at 23℃ for 8 hours, and then dry for 16 hours.
The process of letting it dry for several hours was repeated four times, and a final dry weight ratio of 30% was used as a product. The quality of the products at this time was 93.5% excellent and 6.5% excellent, with no products of inferior quality found. As described above, by performing the initial astringency removal drying of raw persimmons by the method of the present invention, the astringency removal drying process is completed in about 1/3 of the period compared to the initial drying by solar drying shown in Comparative Example 1. did. Therefore, there are advantages of labor saving and stable shipping time. In addition, the products manufactured in this example have only excellent products and no inferior products at all, and the proportion of excellent products is high, so compared to the method of Comparative Example 1, the product quality is improved. It has been demonstrated that the process is more uniform and the yield is also higher. Furthermore, the results of Comparative Example 2 revealed that the flow direction of the air flow should be upward. Comparative Example 1 This example combines initial astringency removal drying by solar drying and charcoal briquette drying. The raw persimmons after peeling were hung on bamboo poles 2 as shown in Figure 2, and then hung in a well-ventilated glass greenhouse on tiers, and the initial astringency was removed by drying in the sun. The initial astringency removal drying was completed when the dry weight ratio of raw persimmons reached 65%, and drying was then completed by charcoal briquette drying until the dry weight ratio was 30%. FIG. 6 shows the dry weight ratio of fresh persimmons to the number of drying days in this comparative example. Here, the solid line indicates the initial astringency removal drying by sun drying, and the broken line indicates the change in dry weight ratio with respect to the number of drying days when briquette drying was subsequently performed. Table 1 shows the changes in weather during this period.

〔Effect of the invention〕

As explained above, the present invention controls the temperature, humidity, and flow rate of the drying air stream to optimal conditions, and performs the initial astringency-removal drying of raw persimmons with the direction of the drying air stream facing upward. , the quality of the dried persimmons obtained is improved and uniform, and there is no mold, rotten fruit,
Yield is improved by reducing the occurrence of scraping.
Furthermore, since the method allows for continuous drying, there is no need for rest-drying work during the drying process, resulting in labor saving and shortening of drying time.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an example of a drying trolley used in carrying out the present invention, Fig. 2 is a side view showing how to attach raw persimmons, and Fig. 3 is an example of an apparatus carrying out the present invention. The plan view shown in Fig. 4 is Fig. 3 A-A.
5 is a graph showing the change in dry weight ratio with respect to the number of drying days in drying raw persimmons by combining the method of the present invention and briquette drying;
FIG. 6 is a graph showing the change in dry weight ratio with respect to the number of drying days in drying raw persimmons using a combination of sun drying and charcoal briquette drying. 1...Drying trolley, 2...Bamboo pole, 3a-3b...
Bamboo rod holder, 4...Wheel, 5...Thread, 6...Persimmon fruit, 7...Drying device, 7a...Machine room, 7b...
Drying room, 8... Partition wall, 9a, 9b... Drying room partition wall, 10... Hot air fan, 11... Fan, 1
2... Air conditioner, 13... Cooler attached to air conditioner, 14
...Duct, 15 ... Rectifier plate.

Claims (1)

[Scope of Claims] 1. A large number of raw persimmons after peeling are stored in a drying chamber with the fruit bottom facing up, and a drying air flow is introduced into the drying chamber from a supply port to dry the raw persimmons. In the method for producing dried persimmons, the temperature of the drying air flow at the supply port is set to 22 to
30℃, relative temperature 40-85%, average flow rate 0.2
- 1.0 m/sec, the flow direction of the drying air flow in the drying chamber is directed upward, and the fresh persimmon is dried to remove initial astringency in the drying air flow. Method.