JP2023108335A - Production method of dried sweet potatoes - Google Patents

Abstract

To provide a production method of dried sweet potatoes by increasing sweetness and flavor.SOLUTION: A production method of dried sweet potatoes includes: a heating step of steaming and heating sweet potatoes; a peeling step of peeling the skin off the heated sweet potatoes; a slicing step of slicing the peeled sweet potatoes; a far-infrared heating step of heating the sliced sweet potatoes with far-infrared rays; a drying step of drying the sliced sweet potatoes heated by infrared rays; and a finishing step of pressing the sliced and dried sweet potatoes.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing dried sweet potato.

Hoshi-imo is a food product made by steaming and drying sweet potatoes, such as those that are shaped into long and thin plates, those that are dried without being sliced into thin slices, and those that are cut into square bars for easy eating. There is Dried sweet potatoes can be eaten as they are, but roasting them makes them softer, sweeter and more fragrant. Dried sweet potatoes contain a moderate amount of moisture, so they are characterized by their sticky chewiness and the sweetness of sweet potatoes.

Dried sweet potatoes are very popular, and are famous as a winter tradition. Recently, some are sold in vacuum packs.

Dried sweet potatoes are generally produced by steaming sweet potatoes, peeling them, slicing them into pieces of a predetermined thickness, and drying them in the sun or in a dryer. In addition, conventionally, a method of producing dried sweet potatoes by placing the peeled steamed sweet potatoes in a freezer at -5 to 10°C for 4 to 5 hours and freezing them, cutting them into chunks, arranging them on a drying net, etc. and drying them has also been proposed. (See Patent Document 1).

There is also a method of baking the sweet potato instead of steaming it and drying the obtained sweet potato to make sweet potato sweets (see Patent Document 2). A method of steaming for ~3 hours and further fumigating at 40~70°C for 8~96 hours to make dried sweet potatoes has also been proposed (see Patent Document 3).

Utility Model Registration No. 3192798 JP 2014-209894 A Japanese Patent Application Laid-Open No. 2001-204334

However, with the recent increase in gourmet tastes, the above-described method for producing dried sweet potatoes may not satisfy consumers with the sweetness and flavor of dried sweet potatoes.

The present invention has been made in view of such problems, and an object thereof is to provide a method for producing dried sweet potatoes that can improve the sweetness and flavor of the dried sweet potatoes.

The method for producing dried sweet potatoes according to the present invention includes:
A steaming heating step of steaming and heating the sweet potato;
A peeling step of peeling the outer skin of the heated sweet potato,
A slicing step of slicing the peeled sweet potato,
a far-infrared heating step of heating sliced sweet potatoes with far-infrared rays;
A drying process of drying sweet potatoes heated with far infrared rays,
and a finishing step of pressing dried sweet potatoes.

According to the present invention, dried sweet potatoes with improved sweetness and flavor can be produced.

FIG. 2 is a photograph of dried sweet potatoes of Beniharuka produced by the production method according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments are intended to facilitate understanding of the principles of the present invention, and the scope of the present invention is as follows. The scope of the present invention is not limited to the embodiments, and other embodiments in which the configurations of the following embodiments are appropriately replaced by those skilled in the art are also included in the scope of the present invention.

A method for producing dried sweet potatoes according to the present invention includes the following steps. Namely
A steaming heating step of steaming and heating the sweet potato;
A peeling step of peeling the outer skin of the heated sweet potato,
A slicing step of slicing the peeled sweet potato,
a far-infrared heating step of heating sliced sweet potatoes with far-infrared rays;
A drying process of drying sweet potatoes heated with far infrared rays,
and a finishing step of pressing the dried sweet potato. They are explained in the following order.

(1) Steaming Heating Step In the steaming heating step, the washed raw sweet potato is heated for a predetermined time by a steaming method. The heating time is not particularly limited, and can be appropriately selected according to the size and type of sweet potato. In order to obtain a sweet dried sweet potato, it is preferable to steam and heat slowly over a long period of time. Although not particularly limited, it is preferable to steam raw sweet potatoes at 100° C. to 260° C. for 3 to 4 hours.

(2) Peeling step In the peeling step, the sweet potato is peeled after being steamed and heated. Sweet potatoes need to be peeled cleanly for good appearance and texture. Therefore, it is preferable to perform this peeling step while the sweet potato is still hot, that is, immediately after the steaming and heating step. Here, “immediately after the steaming and heating step” means within 30 minutes after the steaming and heating step, preferably within 20 minutes, more preferably within 10 minutes, and most preferably from 1 minute to 10 minutes.

In the peeling process, for example, the steamed sweet potato is cut at the center, and then extruded under a predetermined pressure through a separator to separate the fruit (tuberous root) and the skin, followed by peeling.

(3) Slicing step In the slicing step, the sweet potato after the peeling step is cut into slices of a predetermined size in order to cut the sweet potato into an easy-to-eat size. For example, a sweet potato is cut at a predetermined interval (10 mm to 16 mm in this example) by passing it through a vertical blade that moves up and down in a cutting machine.

(4) Far-Infrared Heating Step The far-infrared heating step is a characteristic step in the method according to the present invention.

In the infrared heating step, the sliced sweet potato is heated with far infrared rays. Far-infrared heating is not particularly limited, but for example, sweet potatoes are heated at 220° C. to 260° C. for 20 minutes to 120 minutes. A far-infrared heating means is not particularly limited, and for example, a far-infrared oven can be used.

Far-infrared heating is a method in which sweet potatoes are irradiated with electromagnetic waves (far-infrared rays) in the range of 3 μm to 1000 μm to directly heat the object to be heated. Molecules and crystals that make up substances each have their own vibrations. Substances that easily absorb far-infrared rays, such as water, commonly have a natural vibration of 3 to 30 μm. Since the wavelength bands of the wavelengths match, they resonate with each other and activate movement at the molecular level. This is called thermal vibration, and causes the temperature of the irradiated material to rise. The far-infrared heating device is not particularly limited, and includes an oven, an oven toaster, an electric heater, an electric furnace, and the like.

(5) Drying Step In the drying step, the sweet potatoes after being heated with far-infrared rays are dried. The drying method is not particularly limited, but for example, it is dried with a warm air dryer under conditions of 55 to 60° C., humidity of 28 to 32%, and drying time of 5 to 6 hours. With this drying method, it is possible to achieve a soft, bright amber color with an appropriate amount of moisture in the finished dried sweet potato. It is also possible to arrange them on a net at intervals and dry them in the sun for 1 to 2 days under natural winter temperature conditions (for example, about 0 to 14° C.). In this drying step, it is preferable to dry the sweet potato until the surface of the sweet potato is slightly dry.

(6) Finishing process In the finishing process, the dried sweet potatoes are pressed to make them easy to eat and easy to pack. The pressing is not particularly limited, but is performed until the thickness reaches 15 to 20 mm, for example. If the thickness of the dried sweet potato is less than 15 mm, the thickness becomes too thin, resulting in poor texture. If the thickness of the dried sweet potato exceeds 20 mm, it is too thick to handle in bagging or the like.

Sweet potatoes used in the method for producing dried sweet potatoes according to the present invention are not particularly limited, but are, for example, the following. That is, "Red Haruka", "Red Red", "Tomi no Kawagoe Potato", "Norin No. 1", "Kokei No. 14", "Red Satsuma", "Miyazaki Beni", "Red Komachi", "Purple Sweet" Road (Purple Potato), Quick Sweet, Ayakomachi (Orange Potato), Tamatoyo, Izumi, Tamaotome, Ginseng Potato, Anno Potato, Ayamurasaki (Purple) Potato)”, “Taihaku Potato”, “Golden Potato”, “Hoshikirari”, “Beni Azuma”, “Beni Masari”, “Tanegashima Potato (Purple Potato)”, “Beni Hayato”, “Kogane Sengan”, Examples include ``Naruto Kintoki'', ``Daei Amusume'', ``Gorojima Kintoki'', ``Shito Imo'', ``Kurigogane'', and ``Caiapo Potato''. "Beniharuka", "Tamatoyo" or "Izumi" suitable for dried sweet potatoes are preferred.

The dried sweet potato obtained by the method for producing dried sweet potato according to the present invention has a very good flavor and a high sugar content, with a Brix sugar content of 25 to 30%.

(1) Steaming and Heating Process Red Haruka from Kagoshima Prefecture was used as the sweet potato. Beniharuka was washed and steamed at 120°C for 4 hours. Beniharuka was steamed and heated in a steaming heater while rotating constantly, so that the whole was cooked evenly. In addition, Beni Haruka was sorted into large and small pieces in the sorting process, and each was heated separately to reduce uneven baking.

(2) Peeling process Next, after steaming and heating, the red haruka is cut at the center, and within 10 minutes, it is put in a separator and extruded under a predetermined pressure to separate the fruit (tuberous root) and the skin, and then the skin is peeled. rice field.

(3) Slicing process Next, the peeled red haruka was put in a cutting machine, cut at intervals of 12 mm by passing it through vertical blades, and cut into easy-to-eat sizes.

(4) Far-infrared heating process Next, the sliced Beniharuka is heated at 240°C using a far-infrared oven, 2 pots, 2 stages, Meijin Yaki SC-D2-AII (product name: manufactured by Ono Food Machinery Co., Ltd.). Heated for 60 minutes. The far-infrared wavelength was 100 μm. In the present invention, since the far-infrared heating process is performed before the drying process, the sweetness of the dried sweet potato can be greatly improved compared to the conventional one.

(5) Drying process After the far-infrared heating process, the Beniharuka was dried with a hot air dryer under the conditions of 58°C, 30% humidity, and 6 hours drying time.

(6) Finishing process Next, the thickness of the dried beniharuka was reduced to 18 mm using a pressing machine. As a result, as shown in FIG. 1, dried sweet potatoes of Beniharuka could be produced.

[Sensory test]
A sensory test was conducted by tasting (blind test) for the dried sweet potato of Beniharuka shown in FIG. 1 produced by the production method according to the present invention. There were 20 panelists, 10 of whom were women, and their ages ranged from 20 to 70. It is a comparison test in eating such as taste and aroma texture.

As a result, it was evaluated that it had a good texture and was delicious as compared with a general roasted sweet potato. In particular, the "example product" produced by the production method of the present invention has a more condensed and rich sweetness and aroma than the "comparative example product", is less sticky, and "will make you want to eat repeatedly" and "will be appreciated by others." I want to recommend it.”

[Sugar content test]
The dried sweet potato of Beniharuka produced in this example was cut into a predetermined size, grated, mixed well with distilled water of 3 times weight %, and filtered with filter paper. : Pocket Brix meter PAL-1: manufactured by Atago Co., Ltd.) was used to measure the Brix sugar content, and the Brix sugar content of the undiluted sample was calculated from the measured value. As a result, the Brix sugar content was 27.9%.

On the other hand, the Brix sugar content was similarly calculated for Beniharuka produced by the production method according to the comparative example, which is a method excluding the far-infrared heating step from the present example, and was 11.8%. Thus, it was objectively demonstrated that dried sweet potatoes with improved sweetness and flavor can be obtained according to the present invention.

It can be used to make dried sweet potatoes.

Claims (8)

A method for producing dried sweet potatoes, comprising:
A steaming heating step of steaming and heating the sweet potato;
A peeling step of peeling the outer skin of the heated sweet potato,
A slicing step of slicing the peeled sweet potato,
a far-infrared heating step of heating sliced sweet potatoes with far-infrared rays;
A drying process of drying sweet potatoes heated with far infrared rays,
A finishing process of pressing dried sweet potatoes,
A method for producing dried sweet potatoes. 2. The method for producing dried sweet potatoes according to claim 1, wherein in said steaming and heating step, raw sweet potatoes are steamed and heated at 100° C. to 260° C. for 3 to 4 hours. 3. The method for producing dried sweet potatoes according to claim 1, wherein the peeling step is started within 10 minutes after the steaming and heating step. The method for producing dried sweet potatoes according to any one of claims 1 to 3, wherein the sweet potatoes are heated at 220°C to 260°C in the far-infrared heating step. 5. The method for producing dried sweet potatoes according to any one of claims 1 to 4, wherein, in the far-infrared heating step, the sweet potatoes are irradiated with electromagnetic waves in a range of 3 μm to 1000 μm. 6. The method according to any one of claims 1 to 5, wherein in the drying step, the sweet potatoes are dried with a warm air dryer at 55°C to 60°C and a humidity of 28 to 32% for 5 to 6 hours. How to make dried sweet potato. The method for producing dried sweet potatoes according to any one of claims 1 to 6, wherein the dried sweet potatoes have a Brix sugar content of 25 to 30%. 8. The method for producing dried sweet potatoes according to any one of claims 1 to 7, wherein the sweet potato is Beniharuka, Tamatoyo or Izumi.