JPH0697943B2 - How to prevent discoloration of fruits - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for improving the shelf life of fruits and preventing discoloration of the fruits. More specifically, it relates to a method for preventing discoloration of a fruit that has been peeled or cut and is coated with acetic acid in order to improve the shelf life of the fruit.

<Prior Art> Today, in supermarkets, convenience stores, and the like, consumers are provided with products in which various kinds of fruits that have been previously peeled or cut have been combined and sealed and packed in a seal pack. Fruits in the form described above
Since the pulp part comes into contact with air, decay or discoloration is accelerated in a short period of time. From the above, a method capable of improving the preservability of the fruit has been desired.

As a method for improving the preservability of the fruit in the form described above, conventionally, malic acid, organic acids such as tartaric acid, and lactose,
Method for coating fresh strawberries with a solution containing sucrose etc.
52-41255) was used. In the case of coating the above-mentioned fruit with a solution mainly composed of an organic acid as described above, among the organic acids, bactericidal property,
When acetic acid, which has a stronger antibacterial property, was used, the storage stability of the fruit was further improved.

<Problems to be Solved by the Invention> Therefore, for the purpose of further improving the preservability of peeled or cut fruits, the present inventors coated a solution containing acetic acid on the fruits and preserved the fruits. I confirmed the sex. As a result, although the storability of the fruit was improved, the problem that acetic acid markedly promotes the discoloration of the fruit was encountered.

<Means for Solving Problems> The inventors of the present invention focused on the above-mentioned problems, and peeled or cut the fruit with acetic acid to improve the storage stability of the fruit. We have conducted intensive research to prevent discoloration. As a result, it was found that discoloration of fruits due to acetic acid can be effectively prevented by adding calcium lactate and / or sodium acetate to a solution containing acetic acid and attaching it to the fruits.

The gist of the present invention completed based on these findings is a method for preventing discoloration of fruits, which comprises applying a solution containing acetic acid and calcium lactate and / or sodium acetate to the fruits that have been peeled or cut.

Hereinafter, the present invention will be described in detail.

Fruits used in the present invention are typified by apples, strawberries, mandarins, kiwis, pineapples, melons, etc., and their forms are those that have been subjected to peeling or cutting treatment, that is, those in which the pulp portion has been exposed to the air. .

Next, in the present invention, for the purpose of improving the storability of the fruit having the above-described form, acetic acid, which has strong bactericidal and antibacterial properties among organic acids, is used to adhere the fruit.

The above-mentioned acetic acid has a strong sourness, is volatile and has a strong irritating odor, and therefore, when eating a fruit to which the acetic acid is attached, the user feels a sense of discomfort in taste or smell. Therefore, the above-mentioned concentration of acetic acid is a concentration at which the above-mentioned uncomfortable feeling is not felt when eating fruits, and a concentration at which the bactericidal and antibacterial ability does not decrease for at least 1 week at 10 ° C, that is, a solution attached to fruits. It is desirable to adjust the content to be 0.5 to 1.0% by weight.

Further, in order to alleviate the above-mentioned uncomfortable feeling, particularly the uncomfortable feeling in taste, granulated sugar or the like can be added to the acetic acid, if necessary.

Further, a thickener such as carrageenan may be added to the above-mentioned solution containing acetic acid so that the solution easily and firmly adheres to the fruit.

As described above, when acetic acid, which is used for the purpose of improving storage stability, adheres to peeled or cut fruits, discoloration of the fruits is promoted. The present invention is characterized in that calcium lactate and / or sodium acetate is added to the above solution in order to effectively prevent the above-mentioned discoloration.

The above-mentioned calcium lactate and sodium acetate are preferably added at a ratio of 0.1 to 0.5% by weight to the solution both when used alone and when used. This can effectively prevent discoloration of the fruit. However, when the ratio of the above addition is 0.1% by weight or less, the effect of preventing discoloration becomes weak,
The disadvantage is that discoloration is accelerated in a short period of time. on the other hand,
When the proportion is 0.5% by weight or more, there is a drawback that it is not suitable for eating because it is accompanied by bitterness when eating.

Further, in the present invention, when a solution to which acetic acid and calcium lactate are added is attached to a chlorophyll-containing fruit such as kiwi and melon, promotion of discoloration of the fruit can be more effectively prevented.

Next, as a specific method for attaching the solution containing acetic acid and calcium lactate and / or sodium acetate prepared as described above to the peeled or cut fruit, dipping, coating, spraying, spraying, etc. are used. It is not particularly limited to these. In addition, acetic acid and calcium lactate and / or sodium acetate may be attached simultaneously or separately. For example, it is possible to use a method in which a solution containing acetic acid is first applied to the fruit, and then calcium lactate and / or sodium acetate is further applied to the surface of the fruit using the method described above. The point is that the solution containing acetic acid and calcium lactate and / or sodium acetate should be in a mixed state on the surface of the fruit to be treated.

Also, a coating layer is formed on the surface of the fruit by applying the above-mentioned solution to the fruit. The thickness of the coating layer increases when a thickening agent such as carrageenan is added to the solution, but it may be formed to such an extent that the coating layer does not cause discomfort when eating the fruit, There is no particular limitation.

<Example 1> Kiwi that had been peeled and then cut was treated with vinegar (acetic acid concentration
5.0%, 10 g), granulated sugar (2 g), thickener (2 g), calcium lactate (0.2 g), sodium acetate (0.2 g) and water (185.6 g) in a solution (200 g). And
By removing the kiwi from the solution, acetic acid,
Kiwi (hereinafter referred to as "fruit A") to which a solution containing calcium lactate and sodium acetate was attached was obtained.

<Example 2> A mandarin orange to which a solution containing acetic acid, calcium lactate and sodium acetate was adhered (hereinafter referred to as "fruit B") by using the same method as in Example 1 except that kiwi was changed to strawberry. Called).

<Comparative Example 1> Kiwi that had been peeled and then cut was treated with vinegar (acetic acid concentration
5.0%, 10 g), granulated sugar (2 g), thickener (2 g) and water (186 g) in a solution (200 g). And
The kiwi was taken out of the dipped solution to obtain kiwi (hereinafter referred to as "fruit C") to which an acetic acid solution to which calcium lactate and sodium acetate were not added was attached.

Comparative Example 2 A mandarin orange to which an acetic acid solution to which calcium lactate and sodium acetate have not been added (hereinafter, referred to as "fruit") is used by the same method as in Comparative Example 1 except that kiwi is changed to strawberry. D ").

Next, the fruits A and B obtained from the above-mentioned Examples 1 and 2 and the fruits C and D obtained from Comparative Examples 1 and 2 were respectively heated at 10 ° C.
A storage test was carried out at the temperature of 1 week for 1 week. The results are shown in Table 1.

As is clear from Table 1, fruits A, B, C and D are
Since the solution containing acetic acid was attached, the growth of mold, yeast, lactic acid bacteria, etc. could be prevented.

Regarding the effect of preventing discoloration, almost no discoloration was observed in Fruit A, which was similar to the color at the time of peeling.
Also, with regard to fruit B, after one week, it was slightly darker than the original cut treatment, but fruit D
Compared to the discoloration of No. 3, the degree of promotion was considerably suppressed.
However, the fruit C changed to a whitish color after about one day. Also, with regard to Fruit D, after about 2 days, it was considerably darkened.

<Effects of the Invention> From the above, according to the present invention, the peeling or cutting-treated fruit is adhered with a solution containing acetic acid and calcium lactate and / or sodium acetate, whereby the storability of the fruit is further improved. The discoloration of the fruit caused by acetic acid can be effectively prevented.
Therefore, it is possible to provide a remarkable effect that it is possible to provide a fruit that has been subjected to a peeling or cutting treatment that is excellent in storability and appearance. In particular, when calcium lactate is added to a solution containing acetic acid and the solution is attached to a fruit containing chlorophyll such as kiwi and melon, promotion of discoloration of the fruit can be more effectively prevented. That is, the remarkable effect can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kiyoshi Shibuya 1-5-7 Mikitei-cho, Higashi-Osaka City, Osaka Prefecture House Food Industry Co., Ltd. Ken Ugoi (56) Reference JP-A-52-41255 (JP) , A) JP-A-47-35165 (JP, A) JP-A-56-160959 (JP, A)

Claims (1)

[Claims] 1. A method for preventing discoloration of fruits, which comprises applying a solution containing acetic acid and calcium lactate and / or sodium acetate to peeled or cut fruits, wherein the ratio of acetic acid contained in the solution is 0.5 to 1.0. % Of calcium lactate and / or sodium acetate is 0.1-
A method for preventing discoloration of fruits, which comprises 0.5% by weight.