阅读说明：本技术 一种多酚氧化酶抑制剂及其应用 (Polyphenol oxidase inhibitor and application thereof ) 是由 陈美玲 季天晨 于 2019-11-22 设计创作，主要内容包括：本发明公开了一种多酚氧化酶抑制剂及其应用,属于精细化工领域。本发明利用特定的氧化可得然胶作为多酚氧化酶抑制剂,实现对多酚氧化酶活性的抑制,使得面粉及其面制品具有很好的抗氧化性、防褐变及抗菌效果；还可以应用于化妆品中,抑制黑色素的形成,起到增白的效果,可广泛用于日用化学品和食品工业中,具有较为广阔的应用前景。(The invention discloses a polyphenol oxidase inhibitor and application thereof, belonging to the field of fine chemical engineering. The specific oxidized curdlan is used as the polyphenol oxidase inhibitor, so that the polyphenol oxidase activity is inhibited, and the flour and flour products thereof have good oxidation resistance, browning prevention and antibacterial effects; can also be applied to cosmetics to inhibit the formation of melanin, has whitening effect, can be widely applied to daily chemicals and food industry, and has wider application prospect.)

1. A method for inhibiting polyphenol oxidase, which comprises using oxidized curdlan as a polyphenol oxidase inhibitor; the oxidized curdlan is completely carboxylated curdlan at the C-6 position, and the structure is as follows:

wherein R is-COONa or-COOH; n is 300-.

2. The method as claimed in claim 1, wherein the molecular weight of the curdlan oxide is 50-200 ten thousand.

3. A method for inhibiting flour oxidation, which is characterized in that oxidized curdlan is used as an antioxidant; the structure of the oxidized curdlan is as follows:

wherein R is-COONa or-COOH; n is 300-.

4. The method as claimed in claim 2, wherein the mass fraction of oxidized curdlan relative to flour is 0.2% -0.5%.

5. The antioxidant flour is characterized in that oxidized curdlan is used as an antioxidant, and the mass fraction of the oxidized curdlan relative to the flour is 0.2% -0.5%; the structure of the oxidized curdlan is as follows:

wherein R is-COONa or-COOH; n is 300-.

6. The antioxidant flour according to claim 5, wherein the mass fraction of the oxidized curdlan relative to flour is 0.3% -0.4%.

7. Use of the antioxidant flour of claim 5 or 6 in the field of dough processing.

8. An anti-browning dough sheet, characterized in that the dough sheet is prepared by kneading and pressing the antioxidant flour of claim 5 or 6.

9. The dough sheet of claim 8, wherein the dough is prepared by mixing 10g of water with 25g of antioxidant flour.

10. A cosmetic containing curdlan is characterized in that curdlan is used as a melanin inhibitor in the cosmetic; the structure of the oxidized curdlan is as follows:

wherein R is-COONa or-COOH; n is 300-.

Technical Field

The invention belongs to the field of fine chemical engineering, and particularly relates to a polyphenol oxidase inhibitor and application thereof.

Background

Polyphenol oxidase (EC 1.14.18.1), also known as Tyrosinase (TY), is a bifunctional, copper ion-containing oxidase, has both catechol and cresol enzyme activities, and participates in browning reactions. Polyphenol oxidase is a tetramer containing 4 copper atoms and 2 aromatic compound binding sites per molecule, including phenolic substrates. Also contains a distinct oxygen-copper binding site. Polyphenol oxidase belongs to the class of oxidoreductases, is the main rate-limiting enzyme in the process of melanin formation, and the activity of polyphenol oxidase determines the quantity of melanin formation; most of the whitening products in the market are mainly tyrosinase inhibitors. The melanin is prepared by oxidizing tyrosine to generate 3, 4-dihydroxyphenylalanine under the action of tyrosinase containing high-valence copper ions, oxidizing the tyrosine to dopaquinone and further oxidizing the dopaquinone to 5, 6-dihydroxyindole, and polymerizing the dopaquinone and the dopaquinone.

Browning of mature fruits and vegetables during storage and processing is a problem that is urgently sought to be solved by the food and food processing industries. The browning causes poor product sense and poor taste, thereby affecting the quality and price of processed products, reducing the purchasing desire of consumers, causing product overstocking and causing vicious circle. In order to solve the problem of enzymatic browning during the storage and processing of fruits, scholars at home and abroad carry out a series of researches, and the most commonly adopted method is to use a chemical additive to inhibit the activity of enzyme in the processing process so as to achieve the aim of reducing the browning degree of products.

In addition, browning, which is a phenomenon of color deepening, often occurs during the processing and storage of the pasta. Browning mainly affects the appearance quality of the semi-finished flour product, greatly reduces the commercial value of the flour product, and makes consumers reluctant to purchase the flour product and dealers require goods return. The situation is often encountered in the production and operation process of staple food industrialization enterprises in some places, and certain loss is brought to the enterprises. The main cause of browning is wheat polyphenol oxidase.

Currently, polyphenol oxidase inhibitors are: kojic acid and derivatives, which are limited to food due to carcinogenic effect, cause dermatitis when used for a long time in cosmetics; ascorbic acid is unstable in nature and easily discolors, so that the application of the ascorbic acid is limited; the use of chemical inhibitors can cause harm to human bodies, and the use range is also limited to a great extent. Therefore, there is an urgent need to develop a safe and effective polyphenol oxidase inhibitor.

Disclosure of Invention

In order to provide a novel and effective method for inhibiting polyphenol oxidase, the invention takes oxidized curdlan as an inhibitor to realize the inhibition effect on polyphenol oxidase. The method has obvious inhibition effect on polyphenol oxidase, inhibits the formation of melanin and also has an antibacterial effect.

In recent years, oxidized polysaccharides have received much attention. Oxidized polysaccharides have a certain antibacterial effect, but no report is found on the inhibitory effect of oxidized polysaccharides on polyphenol oxidase. For example, the curdlan is oxidized and modified based on natural biomolecule curdlan, so that the curdlan is non-toxic, free of side effect and wide in source.

The first object of the present invention is to provide a method for inhibiting polyphenol oxidase by using oxidized curdlan as a polyphenol oxidase inhibitor; the oxidized curdlan is completely carboxylated curdlan at the C-6 position, and the structure is as follows:

wherein R is-COONa or-COOH; n is 300-; are attachment sites.

A second object of the present invention is to provide a method for inhibiting flour oxidation by using oxidized curdlan as an antioxidant; the structure of the oxidized curdlan is as follows:

wherein R is-COONa or-COOH; n is 300-.

The third purpose of the invention is to provide antioxidant flour, wherein the flour takes oxidized curdlan as an antioxidant, and the mass fraction of the oxidized curdlan relative to the flour is 0.2-0.5%; the structure of the oxidized curdlan is as follows:

wherein R is-COONa or-COOH; n is 300-.

In one embodiment of the present invention, the molecular weight of the curdlan oxide is about 50 to 200 ten thousand.

In one embodiment of the invention, the mass fraction of the oxidized curdlan relative to the flour is preferably 0.3% to 0.4%; further preferably 0.32%.

The fourth purpose of the invention is to provide a dough sheet for preventing browning, which is prepared by kneading and pressing the antioxidant flour.

In one embodiment of the invention, the dough kneading is performed after mixing 10g of water with 25g of antioxidant flour.

A fifth object of the present invention is to use the above antioxidant flour in the field of flour product processing.

The sixth purpose of the invention is to provide a cosmetic containing oxidized curdlan, wherein the oxidized curdlan is used as a melanin inhibitor; the structure of the oxidized curdlan is as follows:

wherein R is-COONa or-COOH; n is 300-.

In one embodiment of the invention, the preparation method of the oxidized curdlan comprises the following steps:

(1) dissolving 1g of curdlan in 50mL of 2mol/L aqueous alkali, and stirring at room temperature for 2-3 h;

wherein, the alkali can be NaOH or KOH.

(2) Preheating the solution obtained in the step (1) to 50-60 ℃, adding 2mL of 30% hydrogen peroxide, stirring, mixing, reacting for one hour, then adding 2mL, and reacting for 1 hour. Or adding 2ml of hydrogen peroxide, stirring and reacting for 1 hour, then adding 1ml of hydrogen peroxide, reacting for one hour, and then adding 1ml of hydrogen peroxide to react for half an hour;

(3) adjusting the solution obtained in the step (2) to be neutral by acid;

(4) cooling the solution obtained in the step (3) to room temperature, and filtering the supernatant by using a centrifugal machine; freeze drying the supernatant to obtain oxidized curdlan powder product.

Has the advantages that:

the inhibition of polyphenol oxidase activity is effectively realized by using the oxidized curdlan, and the flour and flour products thereof have good oxidation resistance, browning prevention and antibacterial effects by using the oxidized curdlan as an antioxidant; can also be applied to cosmetics to inhibit the formation of melanin, has whitening effect, can be widely applied to daily chemicals and food industry, and has wider application prospect.

Drawings

FIG. 1 is an infrared spectrum of curdlan compared to oxidized curdlan of the present invention.

FIG. 2 is a photograph of the dough sheet after being placed for 24 hours; wherein (a) is a photograph of the dough sheet obtained in example 1; (b) the photo of the dough sheet without adding the curdlan oxide is taken; (c) a photograph of the patch obtained in comparative example 1.

FIG. 3 is a photograph of the dough sheet after being placed for 5 d; wherein (a) is a photograph of the dough sheet obtained in example 1; (b) the photo of the dough sheet without adding the curdlan oxide is taken; (c) a photograph of the patch obtained in comparative example 1.

Detailed Description