JP2003225050A - Dried yacon and method of producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide dried yacons which have excellent long-term storability without deterioration, retain their natural taste and give good food feeling and to provide a method of readily producing the dried yacons. <P>SOLUTION: The dried yacons are in sliced pieces of yacon tuberous roots, include aliphatic carboxylic acids at least on their surfaces and have a water content of 3-13 wt.%. The dried yacons is produced by slicing yacon tuberous roots, bringing the slices into contact with a solution of aliphatic carboxylic acids, followed by drying the slices with heat. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel dry yacon comprising a root of yacon and a method for producing the same.
More specifically, the present invention provides a dried yacon that does not deteriorate the yacon, has excellent long-term storage stability, retains a natural flavor, and has a good texture, and a method capable of easily producing the dried yacon. is there.

2. Description of the Related Art Yacon, which is a root vegetable of the Asteraceae family native to Central and South America, contains a large amount of fructooligosaccharides in its tuberous roots, and is particularly attracting attention as a material that can be fully enjoyed without adding other seasonings. That is, fructooligosaccharide is one of sugar
It has a sweetness of about / 3 and gives the natural sweetness of yacon as a natural sweetener. However, since yacon is a root vegetable with a high water content of 85 to 87%, it is easy to rot and difficult to store, and it is difficult to distribute it in a raw state. Therefore, Yacon, which is a health food, is strongly demanded for a Yacon product in a distribution state while keeping the natural state as much as possible. As a method for drying vegetables while maintaining such a natural flavor and texture, heat drying such as hot air drying is industrially advantageous. However, yacon has a problem that it has a strong texture and is easily browned. That is, when sliced, there is a tendency that it is oxidized and then turns from green to brown and then black, and in particular, those that are dried by heating have the problem that the above tendency is strong and the commercial value is impaired. Although the browning can be prevented to some extent by adopting a drying method of slicing yacon and decompressing or vacuum frying, it is not only inevitable to sacrifice the natural texture and flavor, but also oil is used. This will force the product to have higher calories. In addition, a dried yacon that has not been browned without using oil has not been proposed yet, and a more natural dried product of yacon, which is attracting attention as a health food, has been desired.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a dried yacon which does not turn brown even if it is not fried and dried, and has a flavor close to a natural state and a good texture. . Further, the present invention is to provide a production method capable of easily producing such a dried yacon by heating and drying.

Means for Solving the Problems The present inventor has conducted extensive studies to achieve the above object. As a result, by containing a specific acid on the surface of yacon and adjusting it to a specific water content, there is no deterioration of yacon and it has excellent long-term storage stability.
Moreover, the dried yacon retains its natural flavor and has a good texture, and the dried yacon is obtained by impregnating slices of yacon with the above-mentioned specific acid and then heating and drying until a specific water content is reached. The inventors have found that it can be obtained by an extremely simple method of denying, and have completed the present invention. That is, in the present invention, at least the surface layer contains an aliphatic carboxylic acid, and the water content is 3 to 1
It is a dried yacon characterized in that it is composed of sliced pieces of the yacon root of 3% by weight. Further, the present invention is
The present invention also provides a method for producing a dried yacon, which comprises contacting a sliced piece of the root part of yacon with an aliphatic carboxylic acid solution and then heating and drying.

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, dried yacon is composed of sliced pieces of yacon root. Such sliced pieces may have a skin or may be dehulled. In addition, the method of slicing is not particularly important, but slicing into slices is done by directly cutting the strong fibers of yacon, and after drying, it may have a chrysanthemum pattern and the fiber parts may be too conspicuous and spoil the aesthetics. It is preferable to cut the yacon sliced pieces along the fibers so that the fibers are not cut. Moreover, the shape of the sliced piece is not particularly limited as long as it is a shape that is easily sliced, such as a sliced piece, a thick sliced piece, a sliced piece, or a dice shape. One of the characteristics of the dried yacon of the present invention is that at least the surface layer of the sliced piece of the root part of the yacon contains an aliphatic carboxylic acid. By containing such an aliphatic organic acid, yacon can be maintained for a long period of time without browning, and while maintaining the water content described in detail later. The above-mentioned aliphatic carboxylic acid can exert a sufficient effect if it is present only in the surface layer portion of the yacon sliced piece. In addition, if the content is too much inside, the effect will reach a ceiling, which is not only economical, but may also reduce the natural flavor of yacon. Therefore, it is preferable that the aliphatic carboxylic acid is contained only in the surface layer portion of the slice piece. The aliphatic carboxylic acids used in the present invention are not particularly limited, but acids such as citric acid, tartaric acid, malic acid and oxalic acid are preferable. These acids have the advantage of being good for the body and relatively inexpensive and easily available. Moreover, as the aliphatic carboxylic acids, salts of the above-mentioned acids, for example, sodium salts, potassium salts and the like can also be used. The browning phenomenon of yacon is said to be caused by an enzyme such as 0-phenol oxidase, and it is known to use an antioxidant such as ascorbic acid to prevent browning in the treatment of raw yacon such as yacon juice. . However, when the above-mentioned ascorbic acid is used in the dried yacon, it is decomposed in addition to preventing the browning for a long period of time by the process of incorporating the ascorbic acid into the yacon by a suitable method described later, or the heating treatment for drying to prevent drying. Maintaining stability is difficult. The dry yacon of the present invention has a water content of 3
It is extremely important that the content is adjusted to 13 to 13% by weight, preferably 5 to 11% by weight, in order to maintain the natural flavor of the yacon roots and to give a good texture. That is, the root root of yacon is originally a watery part, and when the water content is less than 3% by weight, the natural flavor of dried yacon is significantly impaired, and the yacon is very hard and the texture is significantly deteriorated. On the other hand, when the water content exceeds 13% by weight, the long-term storability is deteriorated due to the interaction with the aliphatic carboxylic acid, and in some cases, mold or the like may be generated in a short period of time. In the present invention, the water content (C% by weight) of the dried yacon is the weight (B: g) when the weight becomes constant after the weight (A; g) of the dried yacon is measured and then dried at 100 ° C. ) Was measured and calculated from the following formula based on these measured values. C = (A−B) / A As long as the dried yacon of the present invention satisfies the above conditions, it is sufficiently delicious without any special seasoning, and is as natural as it is, and has high commercial value. However, if it is desired to further process the dried yacon of the present invention, it is possible to season it with various seasonings and sugars. The method for producing the dried yacon of the present invention is not particularly limited, but as described above, as a method for industrially producing the desired dried yacon,
A method in which the sliced piece of the root portion of yacon is brought into contact with an aliphatic carboxylic acid solution and then dried by heating is suitable. First, the root root of yacon is washed with water, and it is sliced in the above shape with or without skin. Next, in order to allow the aliphatic carboxylic acids to be contained in at least the surface layer portion of the obtained sliced piece, the sliced piece is contacted with the aliphatic carboxylic acid solution. The solution of the aliphatic carboxylic acids is generally water as a solvent, but in order to efficiently carry out the impregnation by contact, a solvent that has an affinity for water and is harmless to the human body, for example, ethanol. It is also possible to use as a solution in which Further, the concentration of the aliphatic carboxylic acids is 1 to 4% by weight, preferably 2 to 3% by weight. In addition, the mode of contact is not particularly limited, but when exemplifying a typical mode, a method of immersing in the above aliphatic carboxylic acid solution and a method of spraying the above aliphatic carboxylic acid solution are general. The contact time varies depending on the type and concentration of the aliphatic carboxylic acid solution, the treatment temperature and the like and cannot be unconditionally limited, but is preferably 5 to 30 minutes, particularly 7 to 20 minutes. Further, the temperature at the time of contact is suitably 10 to 35 ° C. The yacon sliced pieces that have been contacted with the aliphatic carboxylic acid solution are drained and then dried. In the method of the present invention, heat drying is preferably used as the drying method, but if the drying temperature is too high, the components of yacon may be altered. A particularly preferable drying method in such a situation is a method using far infrared rays. When dried by this method, the sliced pieces can be stably dried to the desired water content. In this case, the drying temperature is 4
5 to 70 ° C., preferably 50 to 60 ° C. are suitable. In addition, in the above drying, the water content up to 85 ° C.
Drying at a relatively high temperature of 100 ° C. and finishing by drying with the far infrared rays in the final stage can shorten the drying time, which is a preferable drying means.

EXAMPLES Examples will be shown below for specifically explaining the present invention, but the present invention is not limited to these examples. In the examples, the appearance (browning), long-term storability, texture and flavor of the dried yacon were evaluated according to the following criteria. (1) Appearance of the dried yacon (browning) The obtained dried yacon was visually observed and evaluated according to the following criteria. ○: Yellowish and no browning △: Slightly yellowish ×: Browning over the whole (2) Long-term storage property The obtained dried yacon was left in a room at a temperature of 30 ° C, 1
The presence or absence of mildew after a month was visually observed and evaluated. ○: No mold is generated △: Slightly mold is generated ×: A large amount of mold is generated (3) Dried yacon obtained from texture and flavor was asked to be tasted by 10 panelists. The number of people who answered that they were satisfied with the texture and flavor was evaluated according to the following criteria. ○: 7 or more people △: 4 to 6 people ×; 3 people or less Example 1 Freshly ground yacon tubers immediately after harvest were washed with water and then molted. This was sliced in a longitudinal direction (leaving the long direction of the elongated potatoes) to a thickness of about 5 mm with a slicer. This was immersed in a 2% by weight citric acid aqueous solution for 10 minutes. The soaked yacon is drained and then dried using a Vivi-9 dry dryer manufactured by Mitake Electronics Co., Ltd. at a far infrared dryer of 50 ° C. for 18 hours to contain citric acid in the surface layer. A dried yacon with a content of 8% by weight was obtained. Regarding the obtained dried yacon, the appearance (browning) of the dried yacon, the long-term storage stability, the texture and the taste were evaluated, and the results were all good. Example 2 A dried yacon having a water content of 4% by weight was obtained in the same manner as in Example 1 except that the drying time was changed to 25 hours. Regarding the obtained dried yacon, the appearance (browning) of the dried yacon, the long-term storage stability, the texture and the taste were evaluated, and the results were all good. Example 3 A dried yacon having a water content of 7% by weight was obtained in the same manner as in Example 1, except that citric acid was replaced with malic acid. Regarding the obtained dried yacon, the appearance (browning) of the dried yacon, the long-term storage stability, the texture and the taste were evaluated, and the results were all good. Comparative Example 1 A dried yacon having a water content of 10% by weight was obtained in the same manner as in Example 1 except that citric acid was changed to ascorbic acid. The appearance (browning) of the dried yacon, long-term storability, texture and flavor of the obtained dried yacon were evaluated, and as a result, the appearance (browning) of the dried yacon was △, long-term storability was ×, and others were △. there were. Comparative Example 2 A dried yacon having a water content of 1% by weight was obtained in the same manner as in Example 1 except that the drying temperature was 85 ° C. and the drying time was changed to 12 hours. The dried yacon thus obtained was evaluated for appearance (browning), long-term storability, texture and flavor. As a result, the texture and flavor were x, and the others were o. Comparative Example 3 A dried yacon having a water content of 20% by weight was obtained in the same manner as in Example 1 except that the drying time was changed to 13 hours. The dried yacon thus obtained was evaluated for appearance (browning), long-term storage stability, texture and flavor, and the long-term storage stability was x, and others were good.

As can be understood from the above description, the dried yacon of the present invention can be produced by a very simple process of contacting the yacon with the fatty acid carboxylic acid solution and then heating and drying the yacon. , The dried yacon has no deterioration of yacon and is excellent in long-term storage,
Moreover, it retains the natural flavor, has a good texture, and has a very high commercial value. In addition, unlike the vacuum fly drying method, it is close to natural and has low calories because it does not use oil or the like. In addition, the aliphatic carboxylic acids used for the purpose of preventing browning, such as citric acid, bring not only good taste but also good health effects. This is a preserved food that is health-conscious. In addition, the dried yacon of the present invention has utility value as a food material and becomes more delicious depending on the seasoning and has a wide range of applications. Furthermore, it is a very useful dried vegetable that can be restored like fresh yacon by returning it to hot water.

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Claims (2)

[Claims] 1. A dried yacon comprising at least a surface layer containing an aliphatic carboxylic acid and a sliced piece of yacon root portion having a water content of 3 to 13% by weight. 2. A method for producing a dried yacon, which comprises contacting a sliced piece of the root part of yacon with an aliphatic carboxylic acid solution and then heating and drying.