JPS63258567A - Canned drink - Google Patents

Abstract

PURPOSE:To obtain a canned drink having a small amount of aluminum eluted even by long-term preservation and excellent flavor of contents, by sealing a drink having a specific ionic concentration of a chloride and a specific pH, containing a specific amount of phosphoric acid (phosphate), within aluminum can containers. CONSTITUTION:A drink having >=100ppm ionic concentration of a chloride, pH2.6-4.0, correlation of ionic concentration of a chloride <=750XpH-1,800ppm and 20-1,000ppm concentration of phosphate ion of one or more of phosphoric acid (phosphate), pyrophosphoric acid (pyrophosphate) and metaphosphoric acid (metaphosphate) is sealed within in aluminum can containers to give a canned drink having excellent long-term shelf stability and maintaining a refresh ing feeling for a long period free from leakage of contents.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a canned beverage in which an acidic beverage containing 1100 pp or more of chloride ions is sealed in an aluminum canning container. This invention relates to canned beverages with excellent storage stability and flavor properties.

(Prior art) Conventionally, cans containing chloride ions of loOppm or more and containing citric acid, malic acid, etc. and having a pH of 2.5 to 4.0 have been sealed in cans, such as sports drinks, etc., which have been coated on the inside. In recent years, beverage cans such as those described above have been put into practical use, in which acidic beverages are sealed in aluminum canning containers with a coated interior. However, acidic beverages containing the above amount of chloride ions are highly corrosive to aluminum, and if the inner surface protection coating of the aluminum can body or aluminum can lid of the can container is insufficient, the corresponding parts will corrode. The flavor of the contents may change due to the elution of aluminum, or in severe cases, perforation corrosion may progress in the can material, causing holes and leakage of the contents.The contents and canned containers may be kept stable for a long period of time without any change in quality. There is a need for a canned beverage of this type that can be preserved.

On the other hand, the general method for manufacturing aluminum beverage cans is to make the can body by drawing and ironing an aluminum plate, degrease and wash it, then apply a chemical conversion treatment, and then apply a protective coating on the inside of the can body. The outer surface of the can body is painted and printed to create a can container body, the contents are placed in this, and the inner surface of the can body is coated with the same protective coating as above, making it an easy-open aluminum can. Obtained by double seaming the lid.

If the inner protective coating of the canned container body or can lid is insufficient and there is an exposed aluminum metal part, the canned material may be deformed by an external impact after being canned, causing the inner protective coating to crack. If this occurs, the same problems as mentioned above will occur, so it is necessary to apply correction coating to the canned container body and the can lid in advance, and to perform extremely strict quality control.

In addition, as mentioned above, in order to prevent corrosion caused by cracks in the inner protective coating film due to external impacts that occur during the distribution stage of canned goods, it is necessary to increase the chloride ion concentration and pH of the contents. This required various restrictions, such as changing the conditions to make it more difficult to do so.

(Problems to be Solved) The object of the present invention is to solve the above-mentioned problems in aluminum canning containers for beverages such as sports drinks, which contain 1100 pp or more of chloride ions and have a pH of 2.6 to 4.0. Even after long-term storage, there is little elution of aluminum, the flavor of the contents does not change, and the refreshing feeling is maintained for a long period of time.Also, the canned beverage can be used as a canned container without perforation due to internal corrosion and the contents do not leak. It is on offer.

(Means for solving the problems) The present invention contains 1100 pp or more of chloride ions and has a pH of 2.
, 6 to 4.0 in a canned beverage sealed in an aluminum canning container, the chloride ion concentration of the beverage ((CI!, -) ppm)
and pH are set within a range that satisfies the relationship of (c'p-]≦750 x pH-1800, and at least one of phosphoric acid, birophosphoric acid 1, metaphosphoric acid, and their salts in the drink, By containing these phosphate ions at a concentration of 20 to 11,000 pp and sealing them in an aluminum container, a highly practical canned beverage that solves the above-mentioned problems is realized.

In general, the above-mentioned phosphoric acids exhibit an anticorrosive effect against corrosion of unpainted aluminum materials near neutrality, but at pH 2.6~
In an acidic region such as 4.0, the anticorrosion effect is low and, on the contrary, corrosion is accelerated.

However, when a protective coating layer is provided on the aluminum surface, such as a painted aluminum can body or can lid, corrosion progresses from the exposed metal part of the microscopic coating film defect, resulting in corrosion on the coating film. According to their observations, the pH of the part under the paint film where corrosion occurs is different from that of unpainted aluminum material, and it has been found that the pH of the area under the paint film is considerably higher than that of the contents due to cathodic reactions. Therefore, it is believed that the addition of phosphoric acid, etc. of the present invention has a remarkable anticorrosion effect, and has the effect of suppressing the corrosion of the aluminum material under the paint film in areas where the protective coating of can containers and can lids is insufficient. It will be done.

Further, according to the present invention, the refreshing feeling of the contents is enhanced by adding the phosphoric acids, which is extremely convenient for sports drinks and the like. In the present invention, if the content of phosphoric acids is less than 20 pp-, the anticorrosion effect will not be sufficiently exhibited, and if it is used in excess of 11,000 pp, the effect will be saturated, and on the contrary, it will have a subtle effect on the taste of the contents. This is undesirable because of the negative effects.

Preferred examples of the phosphoric acids essential for use in the present invention include phosphoric acid, pyrophosphoric acid, metaphosphoric acid, and their sodium salts, potassium salts, calcium salts, and magnesium salts.

In addition, sports drinks usually contain chloride ions ((
Cf! -)) contains 100 pp+s or more, and further contains organic acids such as citric acid and malic acid, and has a pH of 2.6 to 4.
．． 0 range is used, and furthermore, I! However, in general, the higher the chloride ion concentration and the lower the pH, the more corrosive the canning container becomes.

In this regard, the inventors' studies have revealed that when the chloride ion concentration and pH have a certain relationship, the corrosivity of aluminum canning containers is suppressed.

That is, FIG. 1 shows the chloride ion concentration of the contents and its p
The relationship between H and the amount of aluminum eluted from the contents after storage with these values changed is shown. The contents are 0.3% by weight of organic acid (calculated as citric acid) and 0.01% potassium dihydrogen phosphate.
9 heavy views%! - Using an aqueous solution in which 0.1% by weight of ascorbic acid and 0.03% by weight of calcium lactate were dissolved, salt was added to this to reduce the chloride ion concentration to 0,440,750.
, 11,000 pp, and further added caustic soda to each solution to change the pH, thereby preparing 20 types of aqueous solutions with different chloride ion concentrations and pH.

These aqueous solutions were then heated to 95°C and filled into a 350mj2 aluminum film ironed can (01 can) with a thermosetting coating made of epoxyurea paint formed on the inner surface of the canned container body. After removing the air in the head space by nitrogen blowing, a small amount of liquid nitrogen was added, and the aluminum easy-open can lid was double-sealed to create a can with positive pressure inside the can, which was then heated at 37° 2 in C
Figure 1 shows the amount of aluminum eluted in the contents after the can was stored for several months and then opened.

Contents stored in this way retain their flavor, taste,
Judging from a practical point of view regarding corrosion on the inner surface of canned containers, the amount of aluminum eluted is 1 when stored at 37°C for 2 months.
Must be less than ppm.

When we considered the critical values of the contents (a, b, c in Figure 1), which were in the range of 1 ppm or less, we found that the
The relationship shown in the figure is expressed as an approximate expression (cp-]≦75
0 x pH-1800 However, CZ-3 indicates the chloride ion concentration (unit: ppm) and pH indicates the pH value.

It turned out that it holds true.

In other words, as will be described later, if the contents have a relationship between chloride ion concentration and pH outside the range of this formula, corrosion of the exposed metal on the inner surface of the canned container will occur even if the phosphoric acids are contained. The amount of aluminum eluted from the contents became significant, and the conventional disadvantages could not be resolved.

The above-mentioned tendency was similarly observed in cases containing various ingredients such as those contained in ordinary soft drinks and sports drinks, and was also observed in carbonated drinks containing carbon dioxide gas etc. dissolved therein.

In the canned container of the present invention, the container body and the can lid are made of aluminum, and a resin protective coating layer is provided on the inner surface.
After degreasing and cleaning the can, the inner and outer surfaces are subjected to chemical conversion treatments such as chromate phosphoric acid treatment and zirconium phosphate treatment.Then, the outer surface of the can is painted and printed, and the inner surface is spray-painted. Examples include those on which a resin protective coating layer is formed. The inner resin protective coating layer of the 01 can is a coating resin made of one or more conventionally known resins such as epoxy resin, phenol resin, amino resin, polyester resin, acrylic resin, vinyl resin, and vinyl organosol resin. It can be obtained using In addition, the inner surface of the thin aluminum plate is coated with a protective resin coating, except for the edge joints, and the outer surface is painted and printed, cut into strips, rolled up, and glued on both edges. A seam can made by joining together into a cylindrical shape and sealing an aluminum can lid can also be used as the container body of the present invention.

As a can lid that is attached by seaming after filling the container body with contents, an aluminum easy-open can lid whose inner surface of the can lid is coated with the above-mentioned protective coating of resin is used. This can lid is made by coating the inner surface of a thin aluminum plate with the above-mentioned resin and coating the outer surface with a protective coating if desired, then punching it into a disk shape, forming it into the shape of a can lid, and applying a protective coating to the outer surface. It is obtained by scoring and attaching an opening tension piece, but defects may occur in the coating on the inner surface of the can lid during the scoring process and the process of attaching the opening tension piece. Although a correction coating is applied, the defects are generally minute, and the beverage can of the present invention can be used without any practical problems even without the correction coating.

Furthermore, as a method for sealing the contents in the canned container body, conventional methods may be used, but since the aluminum DI can has a thin can body wall and is easily deformed, when using this method, it is necessary to seal the contents. is placed in the container body, liquefied inert gas such as liquid nitrogen is added, and the can lid is tightened to increase the pressure inside the can, preferably 0.3 to 3 kg at room temperature.
It is preferable to add liquid nitrogen and seal the can so that the internal pressure of the can is /cn+'', since deformation of the thin-walled 01 can can be prevented.

(Example) 0.3% by weight of organic acid in terms of citric acid as beverage content
, phosphates were added to an acidic aqueous solution containing 0.03% by weight of calcium lactate and 6.5% by weight of Brix so that the phosphate ion concentration was as shown in Table 1, and the concentration of phosphates was added to the acidic aqueous solution containing 0.03% by weight of calcium lactate and 6.5% by weight of Brix. Contents were prepared at the indicated pH and chloride ion concentration. This was heated to 95°C, and the inside of the can was coated with a protective coating of epoxy urea resin, and the opening was placed in an aluminum DI can (content: 1350 ml) with a three-tiered neck-in finish, with a head space of 30 m.
1, blow nitrogen gas to remove air, then add a small amount of liquid nitrogen, double-seal an aluminum easy-open can lid whose inner surface is coated with the resin, Canned test cans (numbers 1 to 14) with an internal pressure of 0.3 to 3 kg/cm" were prepared. After storing these for two months, the cans were opened, and flavor evaluation and measurement of the amount of eluted aluminum were carried out. Table 1 shows the results of visually observing and evaluating the corrosion state of the inner surface of the container.

As a result, the flavors of Nos. 1 to 4 without the addition of phosphoric acids and No. 5.6, in which the chloride ion concentration and pH conditions were outside the range of the present invention even if phosphoric acids were added, were poor in flavor, and the aluminum The elution amount also exceeded lppm, and corrosion was observed on the inner surface of the canning container.

On the other hand, all of Nos. 7 to 14, which met the conditions of the present invention, were good.

(Effects) According to the present invention, as is clear from the above description, even if a beverage that satisfies the conditions of the present invention is filled in an aluminum canning container and stored for a long period of time, the inner surface of the aluminum canning container corrodes and the aluminum Since there is no leaching of the beverage, it is effective to provide a canned beverage that retains its refreshing feeling for a long period of time without causing any change in its flavor or taste, and also improves the shelf life of the aluminum canning container. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing the results of a storage test of beverages filled in aluminum canned containers, and FIG. 2 is a diagram illustrating the critical range according to the results of FIG. Figure 1ζI↑3. - pH of contents Figure 2 fTl, τ+'i pH of contents

Claims (1)

[Claims] Contains 100 ppm or more of chloride ions, and has a pH of 2.6 to 4.
．． 0 beverage sealed in an aluminum can container, the beverage contains at least one of phosphoric acid, pyrophosphoric acid, metaphosphoric acid, and salts thereof with a phosphate ion concentration of 20 to 1.
000 ppm, and the chloride ion concentration ([Cl^
-]ppm) and pH satisfy the relationship of [Cl^-]≦750×pH-1800.