JPH11276066A - Anti-darkening agent for banana flesh and prevention of banana flesh darkening - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject anti-darkening agent capable of easily and surely preventing the discoloration of bananas or food/drinks therefrom without having adverse effects on their flavor and palate feeling, by including ferulic acid as active ingredient. SOLUTION: This anti-darkening agent contains, as active ingredient, ferulic acid (3-methoxy-4-hydroxycinnamicacid) having remarkable polyphenol oxidase inhibitory activity. It is preferable that fresh banana flesh is treated with an aqueous solution prepared by dissolving ferulic acid in water so as to be 0.1-0.5 wt.% in ferulic acid concentration to prevent banana flesh darkening phenomenon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blackening inhibitor and a method for preventing blackening of banana flesh after peeling due to the action of polyphenol oxidase.

[0002]

2. Description of the Related Art Banana pulp (hereinafter referred to as banana)
The surface rapidly turns black after being peeled or cut. This is because a part of the cells is destroyed by the impact of peeling or cutting, and the polyphenols contained therein are changed to quinones by the action of enzymes such as polyphenol oxidase, and further oxidatively condensed to produce colored substances. is there.

Conventionally, means for preventing this blackening include:
Add salt; make acidic; heat to inactivate polyphenol oxidase; However, these methods often impair the flavor and texture of bananas or foods and drinks using them, and thus often cannot be sufficiently treated, and cannot be carried out at all depending on the application. Ascorbic acid, a method using a reducing agent such as cysteine and the use of natural antioxidants, such as mulberry bark extract, peony extract, quercetin, rutin, kojic acid, have been proposed, but these natural products are There are problems in potency, color, taste, smell, storage stability, etc., and there are few practically usable ones.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a banana black discoloration which has no adverse effect on the flavor and texture of bananas or foods and drinks using the same, has a remarkable use effect, and is easy to carry out. It is to provide a preventive measure.

[0005]

Means for Solving the Problems The present invention, which succeeded in achieving the above object, is based on a novel finding that ferulic acid shows a remarkable polyphenol oxidase inhibitory action, and is based on banana pulp containing ferulic acid as an active ingredient. A method for preventing blackening of banana pulp, characterized by treating fresh banana pulp with ferulic acid.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Ferulic acid (3-methoxy-4-hydroxycinnamic acid) is a component found in various plants, and the blackening inhibitor of the present invention is isolated from any plant. Any of these can be used. As a commercially available product, there is a product extracted and refined from residual oil generated in a rice bran oil refining process.

This compound exhibits a remarkable inhibitory effect on polyphenol oxidase, and thus has a much better anti-blackening effect on bananas than the natural product-based antioxidant. Moreover, even if the amount attached to the banana is orally ingested with the banana, there is no danger of exhibiting toxicity or other undesirable physiological effects, and it is a tasteless, odorless, colorless and chemically stable substance. It has very favorable properties for use in preventing blackening.

[0008] Ferulic acid is known to exhibit an antioxidant action such as preventing oxidation of fats and oils.
This is because ferulic acid acts as a radical scavenger to stop a chain oxidation reaction, and has nothing to do with prevention of banana blackening based on polyphenol oxidase inhibitory action.

Ferulic acid alone can act as a banana blackening inhibitor because it exhibits the effect of preventing banana blackening even when it is made into an aqueous solution. So, when formulating, sodium acetate, sodium succinate, sodium tartrate, sodium citrate, sodium carbonate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, etc., so that the pH in the use state is about 5-8. It is desirable to add an organic acid salt or an inorganic acid salt having a buffering action. The addition of these salts is also effective in making ferulic acid easily soluble in water (alternatively, ferulic acid may be used in the form of a monosodium salt).

[0010] In addition, gum arabic, dextrin, glucose, lactose, surfactant, ethanol,
The addition of propylene glycol, glycerin and the like is also effective in accelerating the dissolution of ferulic acid and improving the handleability by increasing and diluting the amount.

The black discoloration inhibitor of the present invention may further contain any auxiliary agent for improving the black discoloration prevention effect and improving the usability, and may be in the form of powder, granules or paste. Any dosage form, such as shape, liquid, etc., can be adopted.

In the case where the blackening of bananas is to be prevented using ferulic acid (or the anti-blackening agent of the present invention), the ferulic acid concentration is preferably about 0.05 to 1.0% by weight (desirably). (Approximately 0.1 to 0.5% by weight) is applied to the banana surface. If the concentration is lower than this, the treatment effect is not sufficient, and even if the concentration is higher than 1% by weight, the blackening preventing action is not improved, so that it is useless.

When ferulic acid not containing the above-mentioned pH adjuster or the like is used, the pH is adjusted to 5 to 8 in the solution preparation stage.
It is desirable to adjust to the above.

For attaching the aqueous solution of the blackening inhibitor to the banana, any means such as dipping, spraying, and coating can be employed. It is necessary to perform the treatment as soon as possible after peeling the banana. The blackening cannot be eliminated after the blackening has started, and the progress of the blackening cannot be sufficiently prevented after the treatment.

The processing temperature may be room temperature, and heating is unnecessary unless it is necessary for banana processing.

If the banana to be treated is subjected to a process of crushing or grinding, the blackening inhibitor of the present invention may be mixed at the stage of starting the process.

[0017]

EXAMPLE 1 Ferulic acid 5 having a purity of 85% or more separated from rice bran oil 5
0 g, 100 g of trisodium citrate and 350 g of dextrin were dissolved in 2.5 liters of hot water at 80 ° C., and the obtained solution was concentrated and dried to obtain 500 g of a blackening inhibitor.

Example 2 The anti-blackening agent of Example 1 and ferulic acid as a raw material thereof were examined for the activity of inhibiting the action of polyphenol oxidase, which blackens bananas, by the following test method.

Test method: The following four types of solutions are prepared. Solution A: Polyphenol oxidase (mushroom) solution (using potassium phosphate buffer at pH 6.8; 600 units /
solution B: caffeic acid solution (using potassium phosphate buffer of pH 6.8; concentration: 0.5 mg / ml; containing 0.005 mg / ml of L-ascorbic acid) solution C: potassium phosphate buffer of pH 6.8 Liquid Sample solution: Dissolve the weighed sample in 1 ml of ethanol,
Dilute with liquid C to make a total volume of 100 ml.

Add 1 ml of the sample solution to solution A, pre-incubate at 25 ° C. for 10 minutes, and add solution B to
After incubation for 10 minutes, measuring the absorbance A _t of 475nm by quinones caffeic acid occurs by oxidation.

[0021] In addition to adding the solution C instead of the sample solution by the same procedure as described above, measuring the absorbance A _b of 475 nm.

The same operation as above is performed except that solution C is added instead of solution B, and absorbance A ₀ at 475 nm is measured.

After repeating the above measurement while changing the sample concentration of the sample solution stepwise, the sample concentration · IC _{50 at which the} polyphenol oxidase inhibition rate according to the following formula is 50%:
(Ppm) is determined by interpolation. Polyphenol oxidase inhibition rate = [{A _b − (A _t −A
₀ )} / A _b ] × 100

(Note: The substrate responsible for blackening of bananas by polyphenol oxidase is chlorogenic acid, but chlorogenic acid is oxidized in the test system regardless of the presence or absence of polyphenol oxidase. Inhibition test cannot be performed, therefore, the inhibitory rate of polyphenol oxidase is examined using caffeic acid, which has a chemical structure similar to chlorogenic acid and is oxidized by polyphenol oxidase in the same manner as chlorogenic acid, as a substrate.) Was as shown in Table 1.

[0025]

[Table 1]

Example 3 The anti-blackening agent of Example 1 was dissolved in tap water to make a 0.2% solution, and the banana sliced to a thickness of 5 to 10 mm immediately after peeling was soaked in the solution for several seconds. Thereafter, the banana is taken out of the immersion liquid, shaken off, and then left in the air at 20 ° C. to observe the progress of discoloration with the naked eye. Separately, for comparison, similar observations are made when immersed in tap water and when immersed in 0.2% L-ascorbic acid aqueous solution.
Table 2 shows the test results.

[0027]

[Table 2] Temporal change of banana color 1 hour and 2 hours and 24 hours after taking out the immersion liquid Tap water Yellow Yellow brown Brown Black Ascorbic acid solution White yellow Yellow Yellow brown Brown Black discoloration inhibitor solution Yellow Yellow Yellow Yellow

Example 4 To prepare a banana juice by treating 70 g of banana and 30 g of tap water with a homogenizer for 2 minutes.
Is added. 40 g of the obtained juice is put in a petri dish, wrapped and stored in a refrigerator at 5 ° C., and changes with time are visually observed. Separately, for comparison, a similar storage test is performed for the case where L-ascorbic acid is added and the case where nothing is added. The test results were as shown in Table 3.

[0029]

TABLE 3 banana juice color change over time additives immediately after preparation 6 hours 24 hours 48 hours 72 hours No additive yellow gray brown gray brown black black ascorbic acid 1.0g White Yellow Yellow tan Black Black Black After the Antistatic agent 0.3 g yellow yellow yellow brown yellow brown black 0.5 g yellow yellow yellow yellow yellow brown 1.0 g yellow yellow yellow yellow yellow

[0030]

According to the present invention, it is possible to easily and reliably prevent discoloration of bananas or foods and drinks using them as a raw material without adversely affecting flavor and texture.

Claims (2)

[Claims] 1. An agent for preventing blackening of banana flesh, comprising ferulic acid as an active ingredient. 2. A method for preventing blackening of banana pulp, comprising treating fresh banana pulp with ferulic acid.