JPS63269942A - Tyrosinase inhibitor for food - Google Patents

Abstract

PURPOSE:To obtain a tyrosinase inhibitor for food capable of inhibiting activity of tyrosinase contained in the food and preventing blackening and browning of the food, by using kojic acid and ascorbic acid together. CONSTITUTION:A suitable buffering solution is preferably used to adjust the pH of an aqueous solution containing kojic acid and ascorbic acid or/and an alkali metal salt thereof to about 3.0-7.0 and the aqueous solution is then brought into contact with a food within the above-mentioned pH range.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for inhibiting tyrosinase present in many foods and a composition used therein, and relates to a method for inhibiting tyrosinase activity that the food itself possesses during storage. The present invention provides a method for preserving the freshness of foods that are susceptible to discoloration and deterioration, particularly mushrooms, crustaceans, and fruits and vegetables, and a formulation used therefor.

[Prior art] Sulfur dioxide preparations have been used as tyrosinase inhibitors in foods and have been shown to be highly effective, but due to their toxicity, they are prohibited under the Food Sanitation Law in Japan. There is a residual regulation of 1,100 ppm or less for shrimp and 30 ppm for crabs and other general foods, and there are also bans in some countries such as the United States, so in today's world of intense international logistics, there is a risk of safety. The emergence of food-use tyrosinase inhibitors made from highly natural products has been long awaited.

[Problems to be Solved by the Invention] The present inventors have been searching for tyrosinase inhibitors in natural products for a long time.

Recently published Japanese Patent Publication No. 61-143313, 61-143314
In this issue, it was disclosed that kojic acid has a tyrosinase inhibitory effect and is effective in eliminating age spots and spots when used as a lotion or emulsion.

The present inventors attempted to apply this to the food field, and found that crustaceans (
When tyrosinase was extracted from shrimp (shrimp) and mushroom (pine mushroom) and mixed with tyrosine in vitro, a melanization reaction was tested and its effectiveness was confirmed. However, when we conducted in vivo experiments using kojic acid.

Even if a concentration of kojic acid several tens of times higher than that effective in vitro was used, it was not possible to suppress the blackening of crustaceans such as shrimp and crabs, and the browning of mushrooms such as pine mushrooms and shiitake mushrooms. The present inventors have investigated the development of a practical method and inhibitor for inhibiting tyrosinase in foods such as crustaceans and mushrooms by utilizing the properties of kojic acid.

[Means for Solving the Problems] The present inventors investigated ways to prevent the inactivation of the effects of kojic acid in vivo, and as a result of searching for numerous synergists, discovered that ascorbic acid and its alkali metal salts We completed the present invention by discovering that tyrosinase is very effective and that it works even more effectively by changing the pH for suppressing tyrosinase depending on the target food.

That is, the present invention firstly provides kojic acid and ascorbic acid or (and) an alkali metal salt of ascorbic acid (hereinafter "
The present invention provides a method for inhibiting tyrosinase in food, which comprises contacting the food with an aqueous solution of a mixture of kojic acids (referred to as "ascorbic acids") at a pH of about 3.0 to about 7.0; The present invention provides a tyrosinase inhibitor for foods, which comprises a buffer containing ascorbic acids and whose pH during use can be adjusted to between about 3.0 and about 7.0 depending on the target food.

Foods to which the tyrosinase inhibitor and inhibition method of the present invention can be applied are not particularly limited as long as they contain tyrosinase themselves; Application to crustaceans, especially shrimp and mushrooms, is preferred.

If you try to suppress tyrosinase with kojic acid alone without adding ascorbic acids, you will need about 1000 opρI or more of kojic acid, even if it is kept refrigerated for several days (5℃, 7 days), and simply Not only are these numbers economically meaningless, but in the case of mushrooms, they actually caused the mushrooms to wilt. However, when a small amount of ascorbic acid was added to kojic acid, a surprisingly small amount of kojic acid was effective. For example, in the case of crustaceans, by adding 150 ppm of ascorbic acid, the amount of kojic acid is reduced to about 2000 ppm, and the p.
By adjusting H to about 3.0 to about 5.0, the amount of kojic acid could be reduced to about 400 to about 500 ppm. To be more specific, about 30 ascorbic acids
By blending ppm to about 200pp+m, a clear effect was observed at about 1100pp or more of kojic acid, and about 450ρ
Almost the best effect was obtained with pi. In addition, in the case of mushrooms, add 200 ppm of ascorbic acids and adjust the pH to 5.0 to 7.
．． By adjusting the concentration to 0, the preferred concentration of kojic acid is approximately 20
It was possible to reduce the amount to 0 ppm. In this case as well, ascorbic acids should be added in an amount of about 50 ppm to about 200 ppm.
By incorporating m, the effect was clearly observed at about 50 ppm or more of kojic acid, and almost the best effect was obtained at about 200 ppm. Usually, in the case of crustaceans, the amount of ascorbic acid added is smaller than that of kojic acid, for example, about half to about one-fourth, preferably about one-third, and the pH of the solution is about 3.0.
~5.0 is preferred. Furthermore, in the case of mushrooms, the amount of ascorbic acids added is preferably about the same level as that of kojic acid, but even if it is less or more, there is a suppressive effect. In this case, the pH of the solution is preferably about 5.0 to about 7.0.

In addition, in fruits and vegetables, blackening could be prevented using approximately 150 ppm to approximately 450 ppm of kojic acid and approximately 50 ppm to approximately 150 ppm of ascorbic acids, although there were some differences depending on the type.

To adjust the pH of the solution, an alkali or acid may be added directly to the solution containing kojic acid and ascorbic acids, but it is preferable to use an appropriate buffer; examples of such buffers include Citrate-malate buffer, phosphate buffer, citrate buffer, acetate buffer, Tris buffer,
Many buffers are mentioned, such as veronal buffer. When targeting foods, food additives are also used as buffer solutions.

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited thereby. In addition,
In the following examples, a reagent manufactured by Kanto Kagaku Co., Ltd. was used as kojic acid, and all other products were compliant with food additive standards.

Example 1 Example of preventing blackening of shrimp First, the following formulation was prepared.

Formulation ABCD Kojic acid 4.5 4.5 4.5 4.5 Ascorbic acid 1.5 1.5 1.5 1.5 Citric acid (crystal) 71.3 58.0 41.3 31
．． 0 Anhydrous di-Na phosphate 22.7 36.0 52
．． 7 63.0 The numbers in the table indicate (w/w%) (the same applies to the following examples).

The pH of the 1% aqueous solution of each formulation is as follows.

Preparations A (2,8), B (3,3), C (4
,6), D (5,5).

After killing 50 live Japanese prawns in a refrigerator at 5°C, they were divided into 5 groups of 10 each for a, b, and c.

d and e. at b and ct d were respectively prepared in Formulation A.

After immersing it in a 1% aqueous solution of B, C, and D for 1 minute, it was lifted onto a tray, covered, and stored at 5° C. for 7 days. e is water IQ
After being immersed in water for 1 minute, it was stored in the same manner.

The black discoloration over time (when even one black spot appeared) was as shown in the table below. In the fractions in the table, the numerator is a shrimp house with black discoloration.

1st 2nd 3rd 4th 5th 6th 7th a O/
101/103/103/105/107/107/1
0b O/100/100/100/101/101
/101/10c O/1.00/100/100/
100/102/102/10d O/102/10
4/105/106/108/108/10e O/
104/1010/10 Example 2 Pine mushroom browning prevention preparation ABCD Kojic acid 2.02.02.02.0 Citric acid (crystal) 42.1 36.0 9.5
4.8 Anhydrous di-sodium phosphate 53.9 60.0 8
6.5 91.2 The pH of the 1% aqueous solution of each formulation was as follows.

Formulation p, (4,6), B (5,2), c
(7,0), D (7,4).

50 pine mushrooms with completely white cut ends,
Divide into 5 groups of 10 pieces, each with a.

b, c, d, and e. Preparations A and B were applied to the four groups of pine mushrooms a, b, c, and d, respectively.

After spraying a 1% aqueous solution of C and D until the whole surface is slightly damp, place it on a tray, cover it with a vinyl sheet, and heat it at 10°C.
It was stored for 5 days. Sample e was sprayed with water only and stored in the same manner. Oral browning of pine mushrooms was as follows. The numerator in the fraction in the table is the number of pieces in which browning was observed.

1st 2nd 3rd 4th 5th a O/1
0 2/10 6/10 10/10b O/
10 1/10 3/lo 4/10 6/1
0c O/10 0/10 2/10 3/
10 5/10d O/10 1/10. 4/
10 8/1010/10e O/10 5/
10 10/10 Example 3 Potato browning prevention preparation ABCD Kojic acid 4.54.54.54.5 Ascorbic acid 1.5 1.5 1.5 1.5 Anhydrous di-Na phosphate 6.6 17.7 44 .8 8
0.0 Dihydrogen phosphate K 87.4 76.3 49
．． 2 14.0 The pH of the 1% aqueous solution of each formulation was as follows.

Preparations A (4,9), B (5,4), C (6,
2), DC7,0).

500g washed and peeled, 100g sliced
The portions are a, b, and c for each of the 5 groups.

d and e. a, b, c, and d were respectively Formulation A.

After immersing in 200 mQ of 1% aqueous solution of B, C, and D, drain the water, place on a tray, and cover with a vinyl sheet at room temperature (20°C).
It was stored in E was immersed in water and then stored in the same manner. Browning of potatoes over time was as follows. The degree of browning is expressed as 12, +, ++, +4+, and as the number + increases, it indicates that the browning is progressing.

10 minutes 30 minutes 1 hour 2 hoursa -± + +b -±
+ + C−−± + d−−−± 6 −)−+++ ++++++Example 4
Apple browning prevention preparation ABCD Kojic acid 4.54.54.54.5 Ascorbic acid 1.5 1.5 1.5 1.5 Citric acid (crystal) 78.6 58.9 40.3
23.8 Sodium citrate (crystal) 15.4 35.1
53.7 70.2 The pH of a 1% aqueous solution of each formulation was as follows.

Preparations A (3,0), B (3,6), C (4
,4), D (5,2).

Lin: r500g, skin and core removed, sliced, 100g
Divide into 5 groups of g, a and b, respectively.

c, d, and e. The above four groups a, b, c, and d were immersed in 200 rnQ of 1% aqueous solutions of formulations A, B, C, and D for 30 seconds, drained, taken up on a tray, covered with a vinyl film, and stored at room temperature (20°C). did. Sample e was immersed in 200 mQ of water for 30 seconds and then stored in the same manner. Browning over time was as follows. The degree of browning is -.

It is expressed as ±, -1-, ++, +++, and an increase in tens indicates that browning is progressing.

10 minutes 30 minutes 1 hour 2 hours a −−−± b −± + C−−± + d Master + + C+ ++ ++ +++
[Effects of the Invention] By treating a mixture of kojic acid and ascorbic acid or (and) an alkali metal salt of ascorbic acid at a pH of about 3.0 to about 7.0 depending on the target food, It was possible to suppress the activity of tyrosinase contained in foods, and prevent browning of these foods.

Claims (1)

[Claims] 1. Contains kojic acid and ascorbic acid or (and) an alkali metal salt of ascorbic acid, and has a pH of about 3.0 when used depending on the target food. A food tyrosinase inhibitor comprising a buffer that can be adjusted to a concentration of 0 or more and about 7.0 or less. 2. A method for inhibiting tyrosinase in foods, which comprises bringing the food into contact with an aqueous solution of a mixture of kojic acid and ascorbic acid or (and) an alkali metal salt of ascorbic acid at a pH of about 3.0 to about 7.0.