JP2612785B2 - How to reduce juice acidity - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing the acidity of juice such as citrus fruits and plums.

[0002]

2. Description of the Related Art Juices such as citrus fruits and plums contain organic acids such as citric acid and malic acid related to sourness, sugars such as glucose and fructose related to sweetness, other amino acids, lipids, ash, and vitamin C. Including, its aroma and flavor have been favored by many people and used for food. However, some fruit juices have a strong sour taste, and it is desired to reduce them, and a method has been proposed.

[0003] For example, as a method for reducing acidity related to sourness from citrus juice, a magazine, Fla. Stat
e. Hort. Soc. Proc. 73, 21
No. 6 (1978), an electrodialysis tank comprising a cathode compartment, an anode compartment, a plurality of desalination compartments and a plurality of washing compartments is used, in which the cathode and the anode are separated only by an anion exchange membrane. When orange juice is passed through the salt compartment and a direct current is passed between the cathode and anode through an alkaline solution such as KOH or NaOH in the cathode compartment, the anode compartment, and the washing compartment, citric acid in the orange juice is removed from the washing compartment. It has been reported that hydroxyl ions transferred through an anion exchange membrane turn into citrate ions, which are transferred to and removed from a washing chamber through an anion exchange membrane. However, according to this method, although the citric acid concentration in the orange juice is reduced, the pH value is increased and an alkaline odor is generated, and the taste value as the orange juice is rather lowered.

[0004] Magazines, Z.A. Lebensmitt
el-Technol-Verfahren, 28, 2
29 (1977), one cation exchange membrane and two anion exchange membranes were alternately installed between a cathode and an anode, and a cathode chamber, an anode chamber, a plurality of washing chambers, and a plurality of An electrodialysis tank consisting of a salt chamber and a plurality of concentrating chambers is used. The desalting chamber is passed with Satsuma mandarin juice, and the washing chamber is KOH or Na.
When an alkaline solution such as OH is passed through, an electrolyte solution is passed through the concentration chamber, and a direct current is passed between the cathode and the anode, the citric acid in the Satsuma mandarin juice is transferred from the washing chamber through the anion exchange membrane to the citric acid. It has been reported that the ions become ions and are removed by moving to the concentration chamber through the anion exchange membrane. As a result, the concentration of citric acid in the juice of Satsuma mandarin is reduced. However, in this method, although the citric acid concentration of the orange juice is decreased, the pH value of the orange juice is increased to generate an alkaline odor, and the taste value of the orange juice is rather reduced.

[0005] Further, for other juices, especially plum juice,
Although it is desired to reduce acidity while keeping the characteristics of aroma and flavor, it has not yet been performed.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a technique for producing juice which reduces the acidity of the juice, regulates the acidity while keeping the characteristics of flavor, flavor and sweetness alive and does not give an alkaline odor. With the goal.

[0007]

According to the present invention, a cathode and an anode are alternately partitioned by a cation exchange membrane and an anion exchange membrane, and a cathode compartment, an anode compartment, a plurality of desalination compartments and a plurality of desalination compartments are provided. An electrodialysis tank composed of a concentration chamber is used. In the desalination chamber of the electrodialysis tank, an alkali is added to circulate fruit juice having a pH value of 3.20 or more, and an electrolyte solution is circulated in the concentration chamber. This is a method for reducing the acidity of fruit juice, which comprises performing an electrodialysis treatment by passing a direct current between a cathode and an anode.

The juice of the present invention includes citrus juice and plum juice. Examples of citrus juice include juices squeezed from citrus fruits such as Satsuma mandarin orange, navel, Valencia orange, grapefruit, lemon, lime, yuzu, kabosu, sudachi, etc. For example, concentrated citrus juice concentrated to 1/3 to 1/10 is also included. Plum juice is a liquid in which the components are eluted from plum fruits (excluding nuclei). Specific examples of plum juice are obtained by crushing and filtering plum nuts to reduce the amount of pectin by crushing and pulverizing ume nuts, and then removing the pulp using a centrifuge, followed by filtration to obtain plum juice. Extraction method by mixing fruit and powdered sugar to obtain plum juice by osmotic pressure extraction: Frozen juice method in which plum fruit is rapidly frozen, left for a certain period of time, then thawed and centrifuged or pressed to obtain plum juice. According to: Plum vinegar eluted from ume nuts when making ume dried by salting plum fruits: Desalted ume vinegar after completion of salting by ion exchange resin treatment or ion exchange membrane electrodialysis treatment Desalted plum vinegar and the like can be mentioned, but the moisture of plum juice or plum vinegar is evaporated, for example, 1/3 to 1 /
The concentrated plum juice or concentrated plum vinegar concentrated to 10 is also included.

In the present invention, the acidity means the concentration of an acidic component contained in fruit juice, and is a factor relating to acidity. Generally, when the acidity is high, a strong acidity is felt, and when the acidity is low, a weak acidity is felt. The sourness of fruit juice largely depends on the concentration of organic acids contained therein, especially citric acid. In the present invention, the pH value is a negative logarithmic value of the hydrogen ion concentration of fruit juice at 25 ° C.

The method of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of an apparatus used to carry out the present invention. In FIG. 1, reference numeral 11 denotes an ion exchange membrane electrodialysis tank. In the electrodialysis tank 11, a cathode 12 and an anode 13 are alternately partitioned by a cation exchange membrane 14 and an anion exchange membrane 15, and a cathode chamber 16, an anode chamber 17, and a plurality of desalination chambers 1 are provided.
8. A plurality of concentration chambers 19 are formed. Reference numeral 20 denotes a desalting solution tank, 21 denotes an alkali addition line, 22 denotes an acid addition line, and 23 denotes a stirrer. 24 is a concentrate tank, 25
Is a water supply line, and 26 is a concentrate discharge line.

Normal fruit juice, for example, having a pH value of 1.20
Fruit juice such as citrus fruits and plums of 3.00 is desalted in tank 2 of Fig. 1.
Then, the pH value is adjusted to 3.20 or more by adding alkali through the alkali addition line 21 while stirring with a stirrer 23. By the addition of the alkali, organic acid ions and alkali ions other than the organic acid are present in the fruit juice.

The fruit juice having a pH value of 3.20 or more is supplied to a desalting solution circulating pump 27 and a desalting solution circulating pipeline 28, 29.
Is circulated through the desalting chamber 18 of the electrodialysis tank 11 using The concentrate tank 24 is first filled with an electrolyte solution such as sodium sulfate or salt, and the circulating pump 30 and the concentrate circulating pipelines 31 and 32 are used to store the cathode chamber 16, the anode chamber 17 and the concentration chamber of the electrodialysis tank 11. Circulate to 19.

In this state, when a direct current is passed between the cathode 12 and the anode 13 of the electrodialysis tank 11, the organic acid ions in the fruit juice pass from the desalting chamber 18 through the anion exchange membrane 15 to the anode.
It is moved to and removed from the chamber 17 and the concentration chamber 19. Alkali ions, anions through cation exchange membrane 14 from the desalting chamber 18
It is moved to and removed from the pole chamber 16 and the concentration chamber 19. Water is supplied to the concentrate tank 24 from a water supply line 25, and a concentrate containing organic acid ions and alkali ions is discharged from a concentrate discharge line 26.

In the present invention, the pH value of the juice in the electrodialysis treatment must be 3.20 or more. When the pH value is 3.20 or more, most of the organic acids contained in the juice become organic acid ions and are removed by electrodialysis. When the pH value is less than 3.20, the ratio of organic acid ions generated from the organic acid is small, and removal by electrodialysis is difficult. The upper limit of the pH value may be as high as possible, but as the pH value increases, the concentration of alkali ions increases, and it takes time to remove this by electrodialysis. Therefore, the upper limit is preferably about 6.0. Preferred pH values are between 3.50 and 4.50.

In the electrodialysis treatment, when no alkali is continuously added to the juice, the pH value of the juice gradually decreases. When the pH value has dropped to 3.00 to 1.20, organic acid ions in the fruit juice have been almost completely removed, and the electrodialysis treatment is completed.

[0016] In the electrodialysis treatment of fruit juice to increase the pH value to 3.20 or more by adding an alkali, the total of organic acids and organic acid ions in the fruit juice being treated has already been reduced to the target concentration. If the pH value is higher than the target value, acid is added to the juice being treated to increase the pH value, for example, to 3.
When the value is lowered to a certain value of 20 or less, the fruit juice contains an organic acid in which an organic acid ion and a hydrogen ion are bonded, an inorganic acid anion generated by the addition of an acid, and an alkali ion which is a residual substance of the first alkali addition. become.

When the electrodialysis treatment is continued on the acid-added fruit juice, the inorganic acid anions are removed from the desalting chamber 18 through the anion exchange membrane 15 to the anode chamber 17 and the concentrating chamber 19. The alkali ions move from the desalting chamber 18 through the cation exchange membrane 14 to the cathode chamber 16 and the concentrating chamber 19 and are removed. Finally, fruit juice having a reduced organic acid concentration and a predetermined pH value is obtained. From the concentrate tank 24, a concentrate containing inorganic acid anions and alkali ions is discharged from a concentrate discharge line 26.

The material of the cathode 12 of the electrodialysis tank 11 is iron, nickel, stainless steel or the like.
As the material of No. 3, graphite, platinum, platinum-plated titanium, or the like is used. As a material of the main body and the piping of the electrodialysis tank 11, polyvinyl chloride is preferable.

In the electrodialysis treatment, the voltage between the cathode and the anode of the electrodialysis tank is set so that the voltage per pair of anion exchange membrane and cation exchange membrane is 0.5 to 2.0 V, and the ion exchange membrane is used. Is preferably adjusted to be 0.1 to ^{3 A} per 1 dm ^{2 of} the ion exchange membrane. The amount of water supplied to the concentrate tank is preferably adjusted so that the concentration of the electrolyte in the concentrate tank becomes 1.0 to 10.0% by weight.

The alkali added to the fruit juice of the present invention is preferably potassium hydroxide for food supplementation or sodium hydroxide for food supplementation. When the alkali is added, heat is generated, so it is necessary to add the alkali gradually or with cooling. When an acid is used, the acid is preferably hydrochloric acid for food addition or phosphoric acid for food addition.

According to the method of the present invention, there is no change in the concentration and the pH value of sugar, amino-type nitrogen, ash, vitamin C, etc., and fruit juice in which only organic acids are reduced to an arbitrary concentration is produced. ADVANTAGE OF THE INVENTION According to the method of this invention, sourness is relieved and very excellent fruit juice with aroma, flavor, and acidity is obtained.
Also, no alkaline odor is generated from the juice. It is believed that the use of the juice produced by the method of the present invention will further expand in the future.

[0022]

The present invention will be described below with reference to examples. Of course, the present invention is not limited to this. In the examples, the pH value is a value of the juice at 25 ° C., and the citric acid concentration is a value including the citrate ion concentration.

EXAMPLE 1 2.0 liters of natural lemon juice having the composition shown in Table 1A is filled in a desalting solution tank 20 shown in FIG. Liquid. As shown in FIG. 1, this solution was applied to a stainless steel cathode 12 and a platinum-plated titanium anode 13 between 20 strongly acidic cation exchange membranes (effective membrane area of one sheet = 2.0 dm ² ) as shown in FIG.
And a strong base type anion exchange membrane (effective membrane area of one sheet = 2.0 dm ² ). Concentrate tank 24
Is filled with 50 g / l sodium chloride solution and circulated through the cathode chamber 16, the anode chamber 17 and the concentration chamber 19,
Electrodialysis treatment was performed by passing a 1.0 A direct current between the anode 2 and the anode 13. Concentrate tank 24
Was supplied with water so that the concentration of the electrolyte became about 50 g / l, and was discharged from the concentrated liquid discharge line 26. In the electrodialysis treatment for 8.0 hours, the cell voltage and the composition of the lemon juice changed from the column in Table 1B to the column F. As a result of the sensory test, the acidity of the lemon juice after the electrodialysis treatment was significantly reduced.

Example 2 The desalted solution tank 20 was filled with 2.0 liters of the same natural lemon juice as used in Example 1, and sodium hydroxide was added thereto to obtain the same composition as in Example 1 (column B). Into the liquid
This solution was circulated through the desalting chamber of the same ion exchange membrane electrodialysis tank as in Example 1, and subjected to electrodialysis treatment for 2.0 hours under the same conditions as in Example 1. The cell voltage and the composition of lemon juice Was as shown in Table 1C. To this solution was added 35% hydrochloric acid to obtain a solution having the composition shown in Table 1D.
The electrodialysis treatment was continued under the same conditions until the total electrodialysis time reached 4.0 hours. As a result, the cell voltage and the composition of the lemon juice changed as shown in Table 1E. As a result of the sensory test, the acidity of the lemon juice after the electrodialysis treatment was significantly reduced.

Comparative Example 1 The same desalting solution tank 20 as in Example 1 was filled with 2.0 liters of the same natural lemon juice as in Example 1, and this solution was drained from the same ion exchange membrane electrodialysis tank as in Example 1. When circulated in a salt room and subjected to electrodialysis treatment under the same conditions as in Example 1 for 8.0 hours, the cell voltage and the composition of lemon juice were as shown in Table 1B.
It changed from the column to the column F. As a result of the sensory test, the acidity of the lemon juice after the electrodialysis treatment was not changed from that of the undiluted solution.

[0026]

[Table 1]

In Examples 1 and 2, the lemon juice after the electrodialysis treatment had a lower citric acid concentration and a considerably lower acidity than the undiluted solution. No decrease was observed in the sugar and amino nitrogen concentrations. As is clear from Comparative Example 1, even if the lemon juice is subjected to electrodialysis treatment as it is, the citric acid concentration does not decrease and the sourness does not decrease.

Example 3 2.0 L of 1/3 concentrated lemon juice having the composition shown in Table 2A was filled in the desalting solution tank 20 shown in FIG. 1, sodium hydroxide was added thereto, and the composition shown in Table 2B was obtained. Solution.
This solution was circulated in the same desalting chamber of the same ion-exchange membrane electrodialysis tank as used in Example 1 under the same conditions as in Example 1.
When the electrodialysis treatment was performed for 16.0 hours, the cell voltage and the concentrated lemon juice composition changed as shown in Table 2F. As a result of the sensory test, the acidity of the concentrated lemon juice after the electrodialysis treatment was significantly reduced.

Example 4 The desalted solution tank 20 was filled with 2.0 liters of the same 1/3 concentrated lemon juice as used in Example 3, and sodium hydroxide was added thereto to obtain the same composition as in Example 3. (Column B)
This solution was circulated to the desalting chamber of the same ion exchange membrane electrodialysis tank as in Example 1, and subjected to electrodialysis treatment under the same conditions as in Example 1 for 5.0 hours. The composition of the lemon juice was as shown in Table 2C. To this solution was added 35% hydrochloric acid to obtain a solution having the composition shown in Table 2D, and the total time of electrodialysis was 8.0 under the same conditions as in Example 1.
When the electrodialysis treatment was continued until the time reached, the cell voltage and the composition of lemon juice changed as shown in Table 2E. As a result of the sensory test, the acidity of the concentrated lemon juice after the electrodialysis treatment was significantly reduced.

Comparative Example 2 2.0 liters of the same 1/3 concentrated lemon juice used in Example 3 was filled in the desalting solution tank 20 in the same manner as in Example 3, and the same solution as in Example 3 was used. Circulating in the desalting chamber of the ion exchange membrane electrodialysis tank,
When the electrodialysis treatment was performed for 6.0 hours, the cell voltage and the composition of the lemon juice changed from the column in Table 2B to the column in Table F. As a result of the sensory test, no change was found in the acidity of the concentrated lemon juice after the electrodialysis treatment.

[0031]

[Table 2]

In Examples 3 and 4, the concentrated lemon juice after the electrodialysis treatment had a lower citric acid concentration and a considerably lower acidity than the undiluted solution. No decrease was observed in the sugar and amino nitrogen concentrations. As is clear from Comparative Example 2, even if the concentrated lemon juice is subjected to the electrodialysis treatment as it is, the citric acid concentration does not decrease and the sourness does not decrease.

Example 5 2.0 liters of natural plum juice having the composition shown in column 3A of FIG.
And the sodium hydroxide was added to obtain a liquid having the composition shown in Table 3B. This solution was circulated to the desalting chamber 18 of the same ion exchange membrane electrodialysis tank used in Example 1, and subjected to electrodialysis treatment under the same conditions as in Example 1 for 6.0 hours. And the composition of plum juice changed as shown in Table 3F. In addition, as a result of the sensory test, the acidity of plum juice after the electrodialysis treatment was considerably reduced.

Example 6 A desalted solution tank 20 was filled with 2.0 liters of the same natural plum juice as used in Example 5, and sodium hydroxide was added thereto to obtain the same composition as in Example 5 (column B). ), And the solution was circulated through the desalting chamber of the same ion exchange membrane electrodialysis tank as in Example 1, and subjected to electrodialysis treatment under the same conditions as in Example 1 for 2.0 hours. The composition of plum juice was as shown in Table 3C. To this solution was added 35% hydrochloric acid to obtain a solution having the composition shown in Table 3D, and the electrodialysis treatment was continued under the same conditions as in Example 1 until the total electrodialysis time was 3.0 hours. The cell voltage and the composition of plum juice were changed as shown in Table 3E. In addition, as a result of the sensory test, the acidity of plum juice after the electrodialysis treatment was considerably reduced.

Comparative Example 3 The same 2.0-liter natural plum juice as used in Example 5 was filled in the desalting solution tank 20 in the same manner as in Example 5, and this solution was filled with the same ion exchange membrane as in Example 5. When circulated through the desalting chamber of the electrodialysis tank and subjected to electrodialysis treatment under the same conditions as in Example 5 for 6.0 hours, the cell voltage and the composition of plum juice changed as shown in Table 3B from Column F to Column F. did. As a result of the sensory test, no change was observed in the acidity of plum juice after the completion of the electrodialysis treatment.

[0036]

[Table 3]

In Examples 5 and 6, the plum juice after the electrodialysis treatment had a lower citric acid concentration and a much lower acidity than the undiluted solution. No decrease was observed in the sugar and amino nitrogen concentrations. As is clear from Comparative Example 3, even if the natural plum juice is subjected to electrodialysis treatment as it is, the citric acid concentration does not decrease and the sourness does not decrease.

EXAMPLE 7 2.0 liters of 1/5 concentrated ume vinegar shown in Table 4A was prepared by desalinating natural ume vinegar by ion-exchange resin treatment and evaporating water with an evaporator. 20 and sodium hydroxide was added to give a solution having the composition shown in Table 4B. This solution was circulated to the desalting chamber 18 of the same ion-exchange membrane electrodialysis tank as used in Example 1.
When the electrodialysis treatment was performed for 17.0 hours under the same conditions as those described above, the cell voltage and the composition of the concentrated ume vinegar changed as shown in Table 4F. As a result of the sensory test, the acidity of the concentrated plum juice after the electrodialysis treatment was considerably reduced.

Example 8 The desalting solution tank 20 was filled with 2.0 liters of the same 1/5 concentrated ume vinegar as used in Example 7, and sodium hydroxide was added thereto to obtain the same composition as in Example 7 ( (B column), and the solution was circulated to the desalting chamber of the same ion exchange membrane electrodialysis tank as in Example 1, and subjected to electrodialysis treatment under the same conditions as in Example 1 for 6.0 hours. The cell voltage and the composition of plum juice were as shown in Table 4C. To this solution was added 35% hydrochloric acid to obtain a solution having the composition shown in column 4D of Table 4.
The electrodialysis treatment was continued under the same conditions until the total electrodialysis time reached 8.0 hours. As a result, the cell voltage and the composition of the concentrated ume vinegar changed as shown in Table 4E. As a result of the sensory test, the acidity of the concentrated plum juice after the electrodialysis treatment was considerably reduced.

Comparative Example 4 2.0 liters of the same 1/5 concentrated ume vinegar used in Example 7 was filled in the desalting solution tank 20 in the same manner as in Example 7,
This solution was circulated through the same desalting chamber of the same ion exchange membrane electrodialysis tank as in Example 7, and subjected to electrodialysis treatment under the same conditions as in Example 7, for 17.0 hours. Changed from the column in Table 4B to the column F. Also,
As a result of the sensory test, no change was observed in the acidity of the concentrated plum juice after the completion of the electrodialysis treatment.

[0041]

[Table 4]

In Examples 7 and 8, the concentration of citric acid in the concentrated ume vinegar after the electrodialysis treatment was smaller than that of the undiluted solution, and the acidity was considerably reduced. No decrease was observed in the sugar and amino nitrogen concentrations. As is clear from Comparative Example 4,
Even if the concentrated ume vinegar is subjected to electrodialysis treatment as it is, the citric acid concentration does not decrease and the sourness does not decrease.

[0043]

According to the present invention, there is no alkali odor and only the concentration of organic acid is reduced, so that the acidity is reduced.
Fruit juice with excellent aroma and flavor can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an ion exchange membrane electrodialysis device used in the present invention.

[Explanation of symbols]

 11 Ion exchange membrane electrodialysis tank 20 Desalinated liquid tank 24 Concentrated liquid tank

Claims (5)

(57) [Claims] 1. An electrodialysis tank comprising a cathode chamber, an anode chamber, a plurality of desalination chambers, and a plurality of concentration chambers, wherein a cathode and an anode are alternately partitioned by a cation exchange membrane and an anion exchange membrane. In the electrodialysis tank, an alkaline solution was added to the desalting chamber to circulate fruit juice having a pH value of 3.20 or more, and an electrolyte solution was circulated to the concentrating chamber to pass a direct current between the cathode and the anode. A method for reducing acidity of fruit juice, which comprises performing an electrodialysis treatment. 2. The method for reducing acidity of juice according to claim 1, wherein the electrodialysis treatment is continued until the pH value of the juice decreases to 3.0 to 1.20. 3. The method according to claim 1, wherein an acid is added to the juice during the electrodialysis treatment to continue the electrodialysis treatment. 4. The method according to claim 1, wherein the juice is a citrus juice. 5. The method of reducing juice acidity according to claim 1, wherein the juice is plum juice.