JP2012019779A - Method of producing dried fruit slice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dried fruit slice having a crisp texture like a rice cracker and further intensified flavor and color of citrus fruits.SOLUTION: The method of producing dried fruit slices includes: a step of freezing and solidifying citrus fruits; a step of slicing the frozen/solidified citrus fruits holding definite shapes into pieces of a prescribed thickness; a step of applying a trehalose solution to the front surface and/or rear surface of the sliced citrus fruits; a step of placing pieces of the sliced citrus fruits with the trehalose solution applied to the front surface and/or rear surface respectively in the developed state without overlapping one another and leaving the sliced pieces under the temperature environment of 80-100°C for drying the sliced pieces; and a step of enclosing the dried fruit slices together with a desiccant in a sealed bag made of an air-tight member.

Description

  The invention of the present application emphasizes the natural ripe sweet flavor of citrus and exhibits a crispy texture like a rice cracker, returning to the original sliced fruit in the presence of water or hot water, and applied to various dishes It relates to a method for producing possible dried fruit slices.

Traditionally, dried fruits have been produced by drying the fruits as they are or after sugaring them with a dryer or sun-dried and used as confectionery materials as preserved foods. Typical examples include dried grapes, dried apricots, pomelo, lemon peel, and the like. Granular fruits such as persimmons are collected from stems, dried as they are, and used as raisins. Fruits with large shapes such as apples and mango are appropriately sized by slicing etc. It has gained. In addition, it has been proposed to bind these small pieces of dried fruits using a binder to form a desired shape such as a block shape or a rod shape (see, for example, Patent Document 1).
The invention disclosed in Patent Document 1 enables a plurality of dried fruit pieces or dice-shaped dried fruits to be bound by a binding agent, so that the overall shape can be changed to a desired shape such as a bar shape, a heart shape, or a block shape. did. The food obtained by the production method disclosed in Patent Document 1 can provide a taste of several kinds of dried fruits with a single confectionery, and can provide a moist texture as a whole. However, it does not become a food that emphasizes the flavor of the fruit intended by the present invention and that has a crunchy texture.
After the sliced citrus fruit is immersed in a trehalose solution, a reduced pressure treatment is performed, and then the normal solution is returned to normal pressure, the immersion solution is discharged from the fruit slice, and freeze-dried production methods have been proposed (for example, Patent Document 2).
The invention disclosed in Patent Document 2 above is to freeze-dry sliced fruit that is sufficiently infiltrated with trehalose to obtain a dried fruit, which has a good resilience in the presence of water, and needs to always stock fresh citrus. There is no convenience, and it is convenient as a regular food that can be reconstituted with water and used for cooking when there is no fresh lemon on the spot. However, the dried lemon obtained by the production method disclosed in Patent Document 2 has a very low moisture content of 2.8%, and is dried by freeze drying, so that the flavor of the material deteriorates when eaten as it is, There was a problem that it did not have a crispy texture and was not delicious.
JP 2006-136184 A JP 2009-101763 A

  The present invention was devised in view of the above-mentioned problems of the prior art, and an object thereof is to provide a method for producing a dried fruit slice that exhibits a rich flavor and a crispy texture concentrated by low-temperature heat drying. And

The invention according to claim 1 is a method for producing a dried fruit slice, the step of freezing and solidifying the citrus fruit, the step of slicing the citrus fruit under frozen and solidified state to a predetermined thickness, and the slice A step of applying a trehalose solution to the surface or / and back surface of the citrus fruit, and a slice of the citrus fruit coated with the trehalose solution on the surface or / and back surface are left standing in a developed state without polymerization. The method comprises a step of drying in a temperature environment of 80 ° C. to 100 ° C. and a step of sealing the dried fruit slice together with a desiccant in a bag made of an airtight member.

Since the invention of the present application uses a citrus fruit that has been frozen and solidified, there is an effect that the fruit shape can be sliced without collapsing.
By freezing citrus fruits, the moisture in the fruits is solidified and ice crystals are formed in the fruit tissue.After thawing, the ice in the fruit tissue is melted, becomes water and is washed away to the outside of the fruit. Forms a cavity with the same shape as the solidified ice, so just by applying trehalose to the surface of the fruit slice, trehalose quickly enters the cavity, and evenly in the tissue of the fruit slice where trehalose has been thawed. There is an effect that comes to exist. Therefore, it is not necessary to immerse the fruit slice in the trehalose solution for a long time, and there is an effect that the shape is not lost.
By using trehalose, there is an effect of suppressing the discoloration of the fruit slice and maintaining the freshness for a long time.

  By using frozen fruits, fruit slicing work is improved, and after thawing, micropores are formed in the fruit tissue, and trehalose solution enters the micropores to increase trehalose's high permeability into the tissue. It was realized. In addition, the fruit slices coated with the trehalose solution were dried at a low temperature, thereby preventing deterioration of the surface color and providing a crisp texture.

An example of a method for producing a dried sliced fruit will be described using Unshu mandarin as an example of citrus fruit.
Leave Satsuma mandarin in a temperature environment below -15 ° C and freeze until the center is solidified. The obtained frozen Satsuma mandarin orange is cut into slices having a cut surface perpendicular to the line connecting the stalk and the thigh and having a thickness of about 1.5 to 3.0 mm to obtain a Satsuma mandarin slice piece. The slice pieces are developed so as not to overlap each other and placed side by side on a metal plate. 30 g of trehalose is mixed with 100 cc of water, the mixture is boiled, and then left in a room temperature environment to return the liquid temperature to room temperature to obtain a trehalose solution with a trehalose concentration of 30%. As trehalose, either α, α trehalose or α, β trehalose may be used. The obtained trehalose solution is applied to the surface of Wenzhou mandarin orange slices placed on a metal plate. In this embodiment, the application method is a method of applying to the surface of each slice piece with a brush, but the present invention is not limited to the application method using a brush. A method of spraying a trehalose solution on a large number of sliced mandarin orange slices arranged side by side on a metal plate and applying the trehalose solution to the surface of the sliced mandarin orange slice is also included in the present invention. The Satsuma mandarin slice with the trehalose solution applied on the surface is left to stand in a temperature environment of 100 ° C. for about 4 hours and dried by heating. After heating, the product is allowed to stand in a normal temperature environment, cooled at normal temperature, and sealed with a desiccant in a bag formed of an airtight resin film to obtain a product.

The obtained dried fruit slices had a bright orange color as a whole, had a ripe rich flavor, and had a crispy texture like a crunchy rice cracker. When eaten as it is, Satsuma mandarin is very delicious with a rich flavor like Kiyomi Tangor with a high sugar content and a crispy texture.
In the present invention, since the trehalose solution is applied to the surface (one side) of the Satsuma mandarin slice, there is no need to immerse in the trehalose solution for a long time as in Patent Document 2, and the Satsuma mandarin slice does not lose its shape and is uniform. Thick shaped dried fruit slices can be obtained. In addition, since the citrus fruit is frozen, the water of the citrus fruit becomes solidified as ice, and ice crystals are generated in the tissue of Unshu mandarin. After thawing, Satsuma mandarin slices became ice water and flowed out of the slice piece. As a result, the juice concentration increased and countless micropores were formed in the tissue, and the trehalose solution quickly entered these countless micropores. On the other hand, the juice of the mandarin orange is mixed with the concentrated juice and the sweetness of trehalose. The skin content other than the flesh and the white part under the skin also have the effect that the sugar content is increased by the trehalose solution that has entered the micropores formed in the tissue, and the whole slice piece exhibits a taste without bitterness in which the flavor of the mandarin orange is concentrated.
Although the present embodiment has been described with an example of Wenzhou oranges, the present invention is not limited to this. It is included in the present invention that citrus fruits such as Kiyomi Tangor and Shiranui, apples, and melon are used as fruits.

Claims (1)

A step of freezing and solidifying citrus fruits;
A step of slicing the citrus fruit in a predetermined thickness after being frozen and solidified,
Applying a trehalose solution to the front or / and back of the sliced citrus fruit;
The citrus fruit slices coated with the trehalose solution on the front and / or back are left to stand without being polymerized and left to dry in a temperature environment of 80 ° C. to 100 ° C. and dried. The manufacturing method of the dried fruit slice which consists of the process of sealing a fruit slice in the bag which consists of an airtight member with a desiccant.