JP2002142707A - Semi-dried sweet potato and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semi-dried sweet potato having delicious taste and high quality, eatable as it is, producible by the heat drying of a whole sweet potato without cutting the potato while preventing the lowering of the taste and flavor such as sweetness in spite of the use of heat-drying process and free from the weather risk on the production. SOLUTION: A sweet potato containing pregelatinized starch, especially sweet potato of the variety of Setsuno-hakuhi is semi-dried with a heating means such as charcoal fire after cutting both tip ends of a whole sweet potato and the semi-dried potato is formed in an arbitrary form and sealed in a sealable bag. Concretely, a sweet potato washed with water is steamed to pregelatinize the starch, skinned, semi-dried as a whole after cutting both tip ends of the potato while gradually lowering the temperature within the range of 60-115 deg.C, formed, sealed in a gas-barrier bag and thermally sterilized to obtain the semi-dried sweet potato.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semi-dried sweet potato in which a single sweet potato is entirely semi-dried, sealed in a gas barrier bag, has a special taste, and can be eaten as it is, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, dried potatoes generally marketed are:
Sweet potatoes are sliced in the vertical direction, and around 10 are packaged in bags. This dried potato may be eaten as it is, but generally, it is a delicious way to eat it with a low heat to the extent that a blister is formed. According to the production method, potatoes harvested in the fall are air-dried, preferably at 10 ° C. or less, and some enzymes act on the starch due to the cold to change the starch into a state easily susceptible to amylase. Thereafter, by steaming, a part of the starch is decomposed into maltose by the action of β-amylase, and the sweetness is enhanced. The fully steamed potato is manufactured by cutting both ends, peeling, vertically slicing to a thickness of about 8 mm, and drying for 6 to 7 days in the sun when the outside temperature is low.

[0003]

However, in this method, high-quality dried potatoes can be produced if sunny weather continues during sun drying, but if rainy or cloudy days continue, the number of dry days will be prolonged, resulting in a semi-dry state. Induces the growth of various bacteria by leaving
The product has a sour smell. Alternatively, sand storms due to strong winds may occur during sun drying, in which case the sand adheres to the product. Such poor quality products cannot be sold, with the risk that the manufacturer must discard. Recently, consumers are more likely to prefer quality products, even if they are somewhat expensive.

Attempts have been made to dry with hot air instead of solar drying in order to avoid the above risk. However, products produced by hot-air drying lack sweetness, are hardened as a whole, and have a reduced texture when eaten. The present invention, while avoiding the risk of solar drying while heating and drying, not only to prevent a decrease in sweetness and flavor, but also to improve the texture,
It is intended to provide a semi-dried potato that can be eaten as it is delicious.

[0005]

Means for Solving the Problems In the constitution of the present invention, a sweet potato in which starch has been pregelatinized, in particular, a whole of which is cut off at both ends, is semi-dried by a heating means such as a charcoal fire. It is characterized by being molded into a shape and sealed in a sealed bag, its manufacturing method is to steam the sweet potato washed with water to gelatinize the starch, peel it, cut only both ends, and do not cut other parts It is characterized by semi-drying while gradually lowering the temperature in the range of 60 ° C. to 115 ° C., molding, sealing in a gas barrier bag, and heat sterilization.

That is, the present invention is based on the fact that starch is converted into α-starch which is easily affected by an enzyme by steaming. The sweet potato is cut only at both ends and the whole is dried without slicing. It was found out and completed. Drying without slicing requires a long date and time, and it is impossible to obtain good quality dried potatoes unless sufficient conditions are met. The present inventor has found that although dried by heating, by drying the whole without slicing, a delicious dried potato can be obtained without losing the taste. Furthermore, by using charcoal as a heating means, the flavor radiating from the charcoal is reflected in the product, and a sweet and rich semi-dried sweet potato having a subtle flavor has been successfully produced.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The sweet potato in the present invention is a so-called sweet potato and is of various varieties. Examples of the main varieties include Bento (Veneeruma), Tadaka (Tamayutaka), Seto no Hakuhi and the like. Seto no Hakuhi is particularly preferred, but not limited thereto. Generally, dried potatoes are steamed and then dried after the whole becomes soft.
Acts such as boiling, frying, and baking gelatinize starch, which is a main component of sweet potatoes, to change the starch into a state that can be eaten deliciously and be susceptible to the action of enzymes. 6 more
An enzyme in the sweet potato having an activation temperature of 0 to 80 ° C. works to divide the starch molecule from the terminal to form maltose.

[0008] The semi-dry in the present invention is a state of being dried to the extent that it has the softness and flexibility of dried persimmon.
Although the exact water concentration of each product cannot be limited, it has more moisture than the commonly sold sliced dried potatoes, and it can be eaten as it is like dried fruits such as dried apricots and dried grapes. It is not solid. In addition, a single sweet potato is pressed flat to a thickness of 0.
It is about 8 to 1.5 cm, stretched into a stick to form a stick, or formed into a flat gourd or any other shape, stored in an individual bag, sterilized and sold.

In order to dry a single sweet potato as a whole, it is necessary to have excellent conditions in which the sunny weather continues in the sun, and in order to reliably obtain a delicious product, other heat sources besides the solar heat on a sunny day must be obtained. . Electric heating, charcoal, firewood, city gas, petroleum, etc. can be considered as the heating method, but if the fuel that generates steam as a result of combustion is used as it is, moisture will be absorbed by sweet potatoes and the taste of the product will be degraded, so indirect heating means It is preferable to employ Charcoal does not generate steam by combustion,
Although the components are not clear, the trace components due to charcoal are absorbed by sweet potatoes and impart a unique flavor.

In the case of using charcoal, if it is used as it is, the temperature becomes too high and the enzyme activity is inhibited. Therefore, a blind is placed horizontally 30 to 60 cm above the burning charcoal surface, and steamed sweet potatoes are arranged in one layer on the bamboo. dry. The temperature at the blinds is 60-115 ° C, preferably 65-110 ° C
It is. At 115 ° C., there is a risk of reaching 120 ° C. by mistake, at which temperature the enzyme is inactivated. If it is lower than 60 ° C., the effect by heating cannot be sufficiently obtained. As the water evaporates as the drying proceeds, the temperature is gradually lowered to prevent extreme drying, and the water content of the final product, that is, the softness is adjusted. In general, the preferred product is obtained in 2 to 4 days. The product obtained is thick, sufficiently sweet, savory and tastes like a confection as it is.

In the production, as in the case of ordinary dried potatoes, they are packed in bags at a relatively low temperature for 20 to 30 days after harvest and air-dried, so that delicious dried potatoes can be obtained. Then wash with water and steam for about 1-2 hours. After steaming, allow to cool and cut both ends of the sweet potato and peel it. The process up to this point is the same as the conventional method for producing dried potatoes. The water is evaporated while heating to about 110 ° C. without slicing or cutting the peeled sweet potato obtained, and the temperature of the finished semi-dried sweet potato is adjusted by lowering the temperature by about 20 ° C. every day. When one sweet potato is dried as a whole, it is preferable to turn the sweet potato upside down once or twice a day. Since it dries in an average of 3 days, the dried product can be stored in a hermetically sealed package and sterilized at 110 ° C. for about 1 hour at room temperature for 1 year.

[0012]

EXAMPLES Example 1 Sweet potatoes of the varieties var. Lacustrine were grown and harvested between October 15 and 30. The harvest was immediately bagged and stored in a cool, well-ventilated place. Although it is ideally 10 ° C. or less, it is controlled by the weather and cannot always have ideal conditions. The saccharification of sweet potatoes progresses under moderate cold conditions,
In mid-November, it was in the best condition for processing. The processing was first carefully washed with water and steamed for 1 hour and 30 minutes. As a result, the starch was completely pregelatinized and was in an edible state. After cooling, both ends of the sweet potato were cut to prepare a shape as a potato, peeled, and used as a dry raw material. The manufacturing process up to this point is the same as the conventional dry potato.

In this embodiment, the fired charcoal fires are arranged evenly and evenly, bamboo blinds are stretched about 40 cm above, and the dried raw material potatoes are closely arranged on the bamboo blinds to form a single layer. After about 12 hours, it was turned upside down. The temperature at the top of the blinds was 108-111 ° C. on the first day. On the next day, since the drying progressed, the amount of charcoal fire was slightly reduced to lower the upper end temperature of the blinds to 85 to 95 ° C., and drying was performed in the same manner.
On the third day, the temperature was further lowered and slowly dried at 65 to 75 ° C. to obtain dried sweet potatoes having elasticity, containing no free water, and having a feeling like dried persimmon. The potato's original shape may be used,
During drying, it can be pressed with a plate or the like to make it into an arbitrary shape such as a flat, bar-shaped, or flat gourd-shaped. Since the product was a whole sweet potato, it had a richness, and the sweetness was much sweeter than ordinary dried potatoes despite artificial heating and drying, and had a unique flavor, and was extremely delicious. This is because sweet potatoes are not sliced or cut, so it is assumed that flavor components originally contained in sweet potatoes stayed without escaping and that trace components derived from wood generated from charcoal fire were absorbed by sweet potatoes. . Also, since it is in a semi-dry state, it can be eaten without further heating.

The obtained semi-dried sweet potatoes are stored and sealed one by one in a sealed bag made of a gas barrier film.
Sterilization was performed at 1 ° C. for 1 hour. Some air remaining when the bag was sealed was absorbed into the contents as a result of the sterilization treatment, and the film came into close contact with the contents as in vacuum packaging. Although the weight of the product differs depending on the size of the raw material potato, it was 40 to 90 g per piece. Even when the dried sweet potato of this example was left at room temperature and opened one year later, no change or deterioration in flavor, texture and appearance could be found.

[0015]

According to the present invention, the whole sweet potato is heated and dried without cutting it, and even though it is heated and dried, the sweetness and the flavor are not reduced and the risk due to the weather is eliminated, and the sweet potato is eaten as it is. Quality semi-dried sweet potatoes can be reliably provided.

Claims (6)

[Claims] 1. A semi-dried sweet potato, characterized in that the sweet potato in which starch has been pregelatinized is semi-dried by heating and sealed in a sealed bag with both ends cut off. 2. The semi-dried sweet potato according to claim 1, wherein the sweet potato cultivar is A. aureus. 3. The semi-dried sweet potato according to claim 1, wherein the heating means is charcoal-fired heating. 4. The semi-dried sweet potato according to any one of claims 1 to 3, wherein the semi-dried sweet potato is pressed flat. 5. The semi-dried sweet potato according to claim 1, wherein the semi-dried sweet potato is formed into a rod shape. 6. The washed sweet potato is steamed to turn the starch into α, peeled, cut only at both ends, and semi-dried at 60 ° C. to 115 ° C. while cutting the other portions without cutting. A method for producing semi-dried sweet potatoes, which is molded, sealed in a gas barrier bag and sterilized by heating.