JPH06153782A - Preparation of dried food - Google Patents

Abstract

PURPOSE:To provide a process for the preparation of a dried food having excellent palatability and the original color tone of raw vegetables, fruits, etc., without adding a colorant. CONSTITUTION:A dried food is prepared by drying a food with hot air to a water-content of 85-40wt.% and then freeze-drying the product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a dry food product, and more particularly to a dry food product having an excellent texture and having an original color tone such as vegetables and fruits without adding a coloring agent. The present invention relates to a method for producing a dry food product that can obtain

[0002]

2. Description of the Related Art Snack foods and instant foods containing dried fruits, fruit slices, vegetable slices, etc. are widely used in Japan, and the production of these dried fruits is
Generally, select a raw material that has little fibrous discoloration, and
Hot air drying methods such as those disclosed in JP 121547 and JP 53-9343, JP 61-271946 and JP 56
-109546, the freeze-drying method, the vacuum drying method, the microwave drying method, etc. are used. However, with the recent taste of gourmet foods and the increasing quality of foods, it is necessary to significantly improve the quality of these products, but the conventional manufacturing methods have limitations.
That is, although the original color tone of fruits, vegetables and the like is maintained by the hot air drying method, the tissues become hard and the texture such as the chewy texture is bad, and when used for instant food, there is a drawback that it is difficult to return. Further, in the freeze-drying method, since the color tone of the product is thin and the tissue becomes sponge-like, it is difficult to use it as a snack food, even when it is used as an instant food. The present inventors have conducted research to improve the drawbacks of the conventional methods and produce high quality dried fruits and vegetables that can be used for both snack foods and ready-to-eat foods.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a dry food which has an excellent texture and can obtain a natural food color such as vegetables and fruits without adding a coloring agent. To aim.

[0004]

Means for Solving the Problems As a result of the studies conducted by the present inventors to solve the above problems, vegetables or fruits were dried with hot air to a predetermined water content and then freeze-dried. It was found that a dry food having an excellent texture and at the same time having an original color tone such as fruits can be obtained. The present invention is
It is based on such knowledge. Therefore, the present invention provides a method for producing a dry food, which comprises subjecting the food to hot air drying until the water content becomes 85 to 40% by weight, followed by freeze-drying. Hereinafter, the present invention will be described in detail.

The raw material of the dry food used in the present invention is not particularly limited, but examples thereof include carrots, red peppers, peppers, tomatoes, cabbage, sweet corn, leeks, parsley, green peas and the like. Fruits such as vegetables, persimmons, kiwi, pineapples, apples and bananas. Generally, it is preferable to slice the food into a thickness of about 3 to 10 mm. This is because uniform and quick drying can be performed. The hot air drying performed in the first step is suitable so that the water content of the food is 85 to 40%, preferably 80 to 60%, particularly preferably 80 to 70%. Hot air drying varies depending on the type of processing object, shape, type of processing equipment, etc.
The temperature of the hot air is 40 to 120 ℃, preferably 60 to 100 ℃, 30
It is suitable to carry out under the condition of from 5 minutes to 5 hours. For example, when using a Sanyo circulation type constant temperature dryer MOV-202F (manufactured by Sanyo Denki Co., Ltd.) to make carrots of 5 × 5 × 5 mm square size to have a water content of about 85%, hot air at 60 ° C. Below, 60
It may be dried for a minute. When the water content is about 75%, it may be dried for 180 minutes in hot air at 60 ° C.
In addition, if you have a relatively high sugar content such as pineapple or kiwi with a water content of about 85%, use hot air at 60 ° C.
It may be dried for 180 minutes. In these cases, the temperature is preferably raised slowly. This is because it is possible to uniformly remove water and shrink the tissue.

The reason why the water content is dried to less than 85% is that if the water content is more than 85%, a dark color tone cannot be obtained in the final product, and 40% or more means 40% or more.
If it is less than%, the texture will be hard. Also, the hot air is set to 40 ° C or higher because if the temperature is lower than 40 ° C, the processing time becomes long and the processing efficiency deteriorates. If the temperature is lower than 120 ° C, the product flavor is higher than 120 ° C. Is deteriorated and browning occurs. In the subsequent freeze-drying treatment, the dried product treated with hot air is frozen at -20 ° C or lower, preferably at about -40 ° C to -50 ° C, the degree of vacuum is set to 3 to 30 Pa, and the drying temperature is 20 ° C to 80 ° C. , Preferably 30
It is preferable to carry out the treatment at -40 to 40 ° C for 3 to 24 hours. further,
The reason why the dried product is kept at −20 ° C. or lower is that the drying (sublimation) efficiency can be enhanced, and the reason why the vacuum degree is limited to 3 to 30 Pa is that the drying efficiency can be enhanced. . The reason why the drying temperature is higher than 20 ° C is that if the temperature is lower than 20 ° C, the drying process will take a long time.
The reason why the temperature is lower than 80 ° C is that deterioration of flavor and browning occur at temperatures higher than 80 ° C.

[0007]

The manufacturing method of the present invention has an excellent texture,
It was possible to obtain a dry food having an original color tone such as vegetables and fruits without adding a coloring agent. Next, the present invention will be described with reference to examples.

[0008]

[Example 1] 100 g of carrot (water content 90%) cut into a size of 5 x 5 x 5 mm square was heated with a hot air dryer (Sanyo circulation type constant temperature dryer MOV-202F (Sanyo Electric special machine ( Co., Ltd.) and subjected to hot air drying treatment under the conditions of 60 ° C. for 60 minutes to obtain carrots having a water content of 84%, which was then frozen at −40 ° C. and then freeze-dried (Kyowa vacuum technology). Kyowa vacuum freeze dryer PLE-20 manufactured by K.K.
It was stored in 4) and freeze-dried under the conditions of a drying temperature of 40 ° C., a drying time of 16 hours, and a vacuum degree of 3 to 30 Pa to obtain hot air and a freeze-dried carrot. [Comparative Example 1] 100 g of carrot (water content 90%) cut into a size of 5 × 5 × 5 mm square was placed in the above hot air dryer and subjected to hot air drying treatment at 60 ° C. for 16 hours to obtain a water content. A carrot only subjected to a hot air drying treatment of 8.5% was obtained. [Comparative Example 2] 100 g of carrot (water content 90%) cut into a size of 5 x 5 x 5 mm square was frozen at -40 ° C and then stored in the above freeze dryer, and the drying temperature was 40 ° C and the drying time was 40 ° C. Freeze-drying treatment was performed for 16 hours under the condition of a vacuum degree of 3 to 30 Pa to obtain carrots only subjected to freeze-drying treatment. [Example 2] A pineapple subjected to hot air and freeze-drying treatment was prepared in the same manner as in Example 1 except that pineapple was used in place of carrot and the hot air drying treatment was performed at 60 ° C for 180 minutes. Obtained. [Example 3] A kiwi that had been subjected to hot air and freeze-drying treatment was prepared in the same manner as in Example 1 except that kiwi was used in place of carrot and that the hot air drying treatment was performed at 60 ° C for 180 minutes. Obtained.

[0009]

[Table 1] Table 1 Color, texture, texture ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 1 ++++++ It was a vivid color that retained the color tone of carrots. The texture was crispy and crunchy. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Comparative Example 1 ++++ ----- Although it had a dark color tone, it had a fairly firm texture. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Comparative example 2 ----- Almost lost the orange color of the carrot The color tone was close to white. It had a light and soft texture. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 2 ++++ +++ Brighter than the original pineapple color tone It was a color. The texture was crispy and crunchy. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 3 ++ ++ A little green was lost, The kiwi had the original color tone. The texture was crispy and crunchy. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ (Evaluation) +++… Very good-… Slightly bad ++… Good --- Bad + + Somewhat good --- Very bad

Claims (1)

[Claims] 1. A method for producing a dried food, which comprises subjecting the food to hot air drying until the water content reaches 85 to 40% by weight, and then freeze-drying the dried food.