JPH01304873A - Method for peeling citrus fruit - Google Patents

Abstract

PURPOSE:To prepare high-quality fruit juice having the fresh flavor and color of raw fruit, from peeled citrus fruit, without using heat-treatment by freezing and thawing a citrus fruit and peeling the fruit. CONSTITUTION:A citrus fruit is frozen at <=-18 deg.C and stored for at least 3-5 days. The frozen fruit is thawed with running water or tepid water and peeled.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is a method for producing fruit juice and fruit pulp (segments) with a fresh flavor without heat treatment, by freezing citrus fruits, thawing them, and then peeling them. Regarding.

[Conventional technology] Conventionally, most citrus fruits have been squeezed by whole fruit extraction, but some methods have also been used to extract juice from the pulp of the fruit after peeling off the outer skin. (referred to as the juicing method).

The peeling and juicing method is superior to the whole fruit juicing method in the following points. In other words, in the case of the whole fruit juice method, the essential oils from the pericarp mix into the fruit juice, which tends to cause oxidized odors (off-flavors) during storage of the product beverage that will be made later. Since there is no oil contamination, such a fear does not arise. Furthermore, the juice yield is higher with the dehulling method, and the pulp content in the resulting fruit juice is higher. Even small mandarin oranges (3 to 5 cm in diameter) that are difficult to peel can be peeled, for example, by pulper.
For example, the juice can be squeezed using a finisher.

[Problems to be Solved by the Invention] However, this peeling and juicing method does not involve directly subjecting the raw fruit to a peeling machine, but rather by blanching the fruit (90~
It is necessary to perform peeling treatment after softening the exocarp by blanching at 95°C or heating by blowing live steam. The peeled pulp is then squeezed, but during blanching, not only the skin but also the pulp is heated, resulting in the generation of off-flavors (commonly known as potato odor or stuffy odor) due to the heat. The negative effects include destruction and reduction of vitamins, fading of natural carotenoid pigments, and depletion of the natural flavor, color, nutritional value, etc. of natural fruit juices.

[Means to solve the problem]

The present invention has been able to solve these problems by first freezing the exocarp of the fruit and then freezing the fruit without applying heat to the fruit.

In the method of the present invention, citrus fruits are first frozen and preserved at a temperature of -18°C or lower.

This freezing can be accomplished by using a plastic tunnel that blows low-temperature air at temperatures below -18°C, or by placing the product in a Class A freezer at temperatures below -18°C. The storage period is preferably 3 to 5 days or more.

Next, the frozen fruit is thawed with running water (17-25°C) or lukewarm water (30-45°C). Thawing time is sufficient in running water for 1 to 2 hours and in lukewarm water for 0.5 to 1 hour.

After thawing, peeling is performed using a peeling machine or by hand, but the tissue of the fruit epidermis becomes soft due to freezing, and the components of the fruit skin tissue undergo a kind of freezing denaturation, causing the entire tissue to become soft and softened, resulting in dehulling. , or peeling becomes very easy.

In addition, peeled fruit juice obtained by blanching has problems with off-flavor (potato odor, stuffy odor), discoloration, and destruction of vitamins due to heat, but the fruit juice obtained by squeezing the peeled fruit pulp according to the present invention has no problems at all. Because it is not heat-treated, it is possible to obtain high-quality fruit juice with the fresh flavor and color of the original fruit.

〔Effect of the invention〕

If this method is applied, the ripe fruit is harvested at its ripening stage when it has the best taste, is frozen and stored immediately after being picked, and the juice is then squeezed as needed, producing fruit juice with a natural fresh flavor at all times of the year. It is possible to operate a fruit juice manufacturing factory all year round, and maintain a balanced production system that is not dependent on the season, which also brings economic benefits to fruit juice production.

Next, the present invention will be explained by examples.

[Example-1] 100 kg of Unshu mandarin oranges were stored in a -18°C freezer in a frozen state for 10 days, thawed in running water (19°C) for 1 hour, and then peeled using a peeler (manufactured by Teijin Seiki Co., Ltd.). was peeled. The 211 peel rate was 98% or more. After peeling, chopper pulper (screen 1.5 mm
φ) to squeeze the juice, and then use a finisher (screen 0.
5 rrrraφ) to obtain 50 kg of juice, which was further degassed under a reduced pressure of 35 mm (mercury column), and then transferred to an instant sterilizer (85'C,
The enzyme was inactivated for 20 seconds), and the fruit juice was rapidly cooled and peeled and squeezed.

Next, Table 1 shows the peeling rate and components of the frozen peeled fruit juice and the blanched peeled fruit juice obtained by unshuumigan.

(Leaving space below next summer) Table 1 Frozen juice Brunch jig juice Br1x (' ) 1
0.8 10.9 Acidity (%) 0.8
5 0.85 Amino nitrogen (mgX) 29.2
4 27.50 Bikumi 7 C (Bχ) 3
Q, 42 27.56 Ash content (%) 0.2
9 0.29 Pulp content (%) 12.00
13.5OL 46.9
'46.8 tone a G, 0 5.3 b 29.0 28.
5? s ability test Furefushi, 1, flavor, stuffy odor 5 (111 peel rate (visual)
911% 95% [Example-2] Freeze lokg in a freezer at 18°C for 3 days, then thaw in lukewarm water (40"C) for 1 hour, and peel off the 8 exocarps by hand. We carried out the following.
At this time, the skin can be peeled off very easily, and the fruit is then carefully cracked and treated with 3.5% hydrochloric acid (20'C) and 1% caustic soda solution (30'C) to remove the skin. Using Yamabe, syrup-pickled f11 stuffing was produced.

1-IJ I'In Jin Nankariko Co., Ltd. Agent Patent Attorney Yu Hiragi Agent Patent Attorney Ishii Page Next

Claims (1)

[Scope of Claims] 1. A method for peeling citrus fruits, which involves freezing citrus fruits, then thawing them, and then peeling them. 2. The method for extracting juice by peeling a citrus fruit according to claim 1, wherein the frozen citrus fruit is peeled after thawing and then the juice is squeezed.