JP2527325B2 - Canned beverage - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a canned beverage in which an acidic beverage containing 100 ppm or more of chloride ions is sealed in an aluminum canned container. The invention relates to a canned container and sealed contents. Storage stability,
The present invention relates to a canned beverage excellent in flavor property.

(Prior Art) Conventionally, as a canned product containing 100 ppm or more of chloride ions and citric acid, malic acid, or the like and containing an acidic beverage having a pH of 2.5 to 4.0, for example, a sports drink or the like is internally coated. Although the one sealed in a steel canned container has been put into practical use, in recent years, a drink canned product in which an acidic beverage as described above is sealed in an aluminum-made canned container is also put into practical use. However, acidic beverages containing the above-mentioned amount of chloride ions are highly corrosive to aluminum, and if the inner surface protective coating of the aluminum can body or the aluminum can lid of the canned container is insufficient, corrosion will occur at that part. If the flavor of the contents changes due to aluminum elution, or if the contents are significantly changed, or if the contents of the cans are leaked, the contents of the cans and the canned containers may remain stable for a long period of time. There was a need for this type of canned beverage that could be stored.

On the other hand, the manufacturing method of aluminum beverage cans is generally
A can body is made by squeezing and ironing an aluminum plate, degreased and washed, and then subjected to chemical conversion treatment, then the inner surface of the can body is coated with a protective coating, and the outer surface of the body is painted and printed, and a can container. Create the main body, put the contents in it,
It is obtained by double-winding an aluminum easy-open can lid, which is made separately and has the same protective coating as the above, on the inner surface side.

If the inner surface protective coating of this canned container body or can lid is inadequate and there is an exposed aluminum metal part, again, after canning, the canned article is deformed by an external impact or the like and cracks in the inner surface protective coating film. If such a problem occurs, the same problem as described above occurs, and therefore, it is necessary to perform correction coating on the canned container body and the can lid in advance, and to perform strict quality control.

In addition, as described above, in order to prevent corrosion caused by cracks in the inner surface protective coating film due to external impacts and the like that occur during the distribution stage of canned food, the chloride ion concentration and pH of the contents are more corroded. Various restrictions were required such as changing to conditions that are difficult to prevent.

(Problems to be solved) The object of the present invention is to ensure that the pH of chloride ion is 100 ppm or more and
2.6 ~ 4.0 beverages, for example, solve the above problems in aluminum canned containers such as sports drinks,
Even if stored for a long period of time, the elution of aluminum is small, the flavor of the contents does not change, the refreshing feeling is maintained for a long time, and even if it is a canned container, no perforation due to internal corrosion does not occur and beverage cans with no leakage of contents To provide.

(Means for Solving Problems) The present invention contains chloride ions in an amount of 100 ppm or more and has a pH of 2.6 to 4.0.
Set in a range satisfying ≦ 750 × relationships pH-1800, ^- the a ^- (ppm [Cl]) and the pH of the beverage chloride ion concentration of the beverage in the beverage canning was sealed in an aluminum canning container [Cl] In addition, at least one of phosphoric acid, pyrophosphoric acid, metaphosphoric acid and salts thereof in the beverage is used as the phosphate ion concentration of 20 to 1000.
By containing ppm and sealing in an aluminum container, an excellent and practical beverage can can be solved in which the above problems are solved.

Generally, the phosphoric acids show an anticorrosion effect against the corrosion of unpainted aluminum materials in the vicinity of neutrality, but the pH is 2.6 to 4.0.
In an acidic region such as, the anticorrosion effect is low, and on the contrary, it promotes corrosion.

However, in the case where a protective coating layer is provided on the aluminum surface such as a painted aluminum can body or can lid, the progress of corrosion from the exposed metal portion of the minute coating film defect portion results in undercoat corrosion. According to these observations, the pH of the corroded area under the coating film is much higher than the pH of the contents due to the cathodic reaction, unlike the case of unpainted aluminum material.
It is known that the pH is high, and therefore the anticorrosion effect of the addition of phosphoric acid or the like of the present invention is remarkable, and corrosion of the aluminum material under the coating film of the canned container and the protective coating of the canned part is insufficient. It is considered that the suppressing effect was exhibited.

Furthermore, according to the present invention, by adding the phosphoric acid, the refreshing sensation of the contents is enhanced, which is extremely convenient for things such as sports drinks. In the present invention, if the content of phosphoric acid is less than 20 ppm, the anticorrosion effect is not sufficiently exhibited, and even if it is used in excess of 1000 ppm, the effect is saturated, and on the contrary, it has a delicate influence on the taste of the contents. Therefore, it is not preferable.

Suitable examples of the phosphoric acid used as an essential component in the present invention include phosphoric acid, pyrophosphoric acid, metaphosphoric acid and their sodium salts, potassium salts, calcium salts, magnesium salts and the like.

Further, in the sports drinks typically chloride ion ([Cl ^-]) is contained more than 100 ppm, further citric acid, pH include organic acids such as malic acid is used is in the range of 2.6 to 4.0 Furthermore, sugars, acidulants, flavors, calcium salts, magnesium salts, etc. are added, but generally, the higher the chloride ion concentration and the lower the pH, the higher the corrosiveness of the canned container. Be looked at.

In this regard, according to the studies made by the inventors, it was found that the corrosiveness of the aluminum canned container was suppressed when the chloride ion concentration and the pH had a constant relationship.

That is, FIG. 1 shows the chloride ion concentration of the contents and its
The relationship between pH and the elution amount of aluminum in the content after changing these and storing is shown. The content is 0.3% by weight of organic acid in terms of citric acid, 0.019% by weight of potassium dihydrogen phosphate, 0.1% by weight of 1-ascorbic acid, and 0.0% of calcium lactate.
Using an aqueous solution in which 3% by weight is dissolved, add salt to this to adjust the solutions with chloride ion concentrations of 0,440,750,1000 ppm, and add caustic soda to each to change the pH, resulting in different chloride ion concentrations and pH. 20 types of aqueous solutions were prepared.

Then, these aqueous solutions are heated to 95 ° C and filled into a 350 ml aluminum squeezing ironing can (DI can) on which a thermosetting coating film made of epoxyurea paint is formed on the inner surface side when the canning container body is filled with nitrogen. After removing the air in the headspace by blowing, add a small amount of liquid nitrogen, double-tighten the aluminum easy-open can lid, and make a can with the positive pressure inside the can. Save for a month,
After that, the can was opened and the amount of aluminum eluted in the contents was measured, which is shown in FIG.

The contents saved in this way are the flavors of the contents,
When judging the taste and corrosion of the inner surface of the canned container from a practical point of view,
Aluminum elution is 1ppm when stored at 37 ℃ for 2 months
Must be: When the critical values (a, b, c in FIG. 1) of the contents within the range of 1 ppm or less were examined, the relationship shown in FIG. 2 was obtained, which was an approximate expression [Cl ⁻ ] ≦ 750 × pH-1800 except [Cl ^-] of chloride ion concentration (in ppm) pH denotes the pH value.

Has been established.

That is, as will be described later, in the contents having a relationship between the chloride ion concentration and the pH outside the range of this formula, even if the phosphoric acid is contained, corrosion of the metal exposed portion on the inner surface side of the canned container is caused. And the amount of eluted aluminum in the contents became large and the conventional inconvenience could not be resolved.

The above tendency is similarly observed when various components such as those contained in ordinary soft drinks and sports drinks are contained, and also in carbonated drinks in which carbon dioxide gas and the like are dissolved.

The canned container of the present invention is one in which the container body and the can lid are made of aluminum and a resin protective coating layer is provided on the inner surface, and the container body of such a configuration is a squeezed and squeezed aluminum can (so-called DI can), After degreasing and cleaning the can, apply chemical conversion treatment such as chromate phosphate treatment and zirconium phosphate treatment to the inner and outer surfaces, then paint print on the outer surface of the can and spray paint on the inner surface to form a resin protective coating layer. I can give you what I made. The resin protective coating layer on the inner surface of such a DI can is a coating resin made of one or more of conventionally known resins such as epoxy resin, phenol resin, amino resin, polyester resin, acrylic resin, vinyl resin and vinyl organosol resin. Is obtained by using. Also, except for the part that becomes the edge joint part of the aluminum thin plate, resin protective coating is applied on the inner surface side, paint printing is applied on the outer surface side, cut into strips, rounded and joined with adhesive etc. Then, a seal can or the like having a cylindrical shape and having an aluminum can lid wound can also be used as the container body of the present invention.

As a can lid to be attached by winding after the contents are put in the container body, an aluminum easy-open can lid having a resin protective coating applied to the inner surface of the can lid is used. This can lid is coated with a protective coating of the above resin on the inner surface of an aluminum thin plate and, if desired, on the outer surface of the aluminum plate, then punched out into a disk shape and molded into a can lid shape. The score can be obtained by attaching a score to the opening tension piece, but a defect may occur in the coating film on the inner surface of the can lid at the time of score processing and attachment processing of the opening tension piece. Although correction coating is applied later, the defective portion is generally minute, and the beverage can of the present invention can be used without any practical problems without correction coating.

Moreover, as a method of sealing the contents in the canned container body,
Although it may be carried out by a method which has been conventionally carried out, since the aluminum DI can has a thin and easily deformable can body wall, when this is used, after the contents are put in the container body, liquefaction of liquid nitrogen etc. and adding the active gas, seaming the can lid with a state of increasing the pressure of Kan'nai, preferably thin DI by the addition of liquid nitrogen so that the can internal pressure of 0.3~3kg / cm ² at room temperature sealed It is preferable because deformation of the container body of the can can be prevented.

(Example) 0.3% by weight of citric acid equivalent organic acid as a beverage content, 0.03% by weight calcium lactate, 6.5% by weight Brix
Phosphates were added to the acidic aqueous solution containing the so as to have the phosphate ion concentration shown in Table 1, and the contents having the pH and chloride ion concentration shown in the table were prepared using an aqueous solution of sodium hydroxide and sodium chloride. This is heated to 95 ° C, the inner surface of the can is coated with a protective coating of epoxyurea resin, and the opening DI is made into a three-tiered necked-in aluminum DI can (capacity 350 ml) with a headspace of 30 ml. To remove the air, then add a small amount of liquid nitrogen, and then double-tighten the aluminum easy-open can lid coated with the resin to protect the inner surface of the can. Test cans (Nos. 1 to 14) having a can internal pressure of 0.3 to 3 kg / cm ² were prepared. Table 1 shows the results obtained by opening the cans after storing them for 2 months, evaluating the flavor, measuring the amount of eluted aluminum, and visually observing the inner corrosion state of the canned container.

As a result, Nos. 1 to 4 without addition of phosphoric acid and Nos. 5 and 6 having conditions of chloride ion concentration and pH outside the scope of the present invention even if phosphoric acid was added, the flavor was deteriorated.
The aluminum elution amount exceeded 1 ppm, and corrosion was observed on the inner surface of the canned container. On the other hand, the numbers 7 to 14 satisfying the conditions of the present invention were all good.

(Effect) According to the present invention, as is clear from the above description, a beverage satisfying the conditions of the present invention will not corrode the inner surface of the aluminum canned container even if it is stored in the aluminum canned container for a long period of time. Does not elute, so there is no change in its flavor or taste,
There is an effect of providing a canned beverage in which the refreshing feeling is retained for a long period of time and the storability of the aluminum canned container is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing the result of a storage test of a beverage filled in an aluminum canned container, and FIG. 2 is a diagram showing the critical range according to the result of FIG.

Claims (1)

(57) [Claims] 1. Containing 100 ppm or more of chloride ions and having a pH of 2.6-
In a beverage can in which a beverage of 4.0 is sealed in an aluminum can container, the beverage has a phosphate ion concentration of at least one of phosphoric acid, pyrophosphoric acid, metaphosphoric acid, and 20 to 1000.
ppm contained, and the chloride ion concentration ^- pH and (ppm [Cl])
A canned beverage characterized in that and satisfy the relationship of [Cl ⁻ ] ≦ 750 × pH−1800.