TW202005542A - Application of sericin peptide for inhibiting vegetable/fruit browning characterized in that the browning of vegetable/fruit caused by phenol oxidase or tyrosinase can be inhibited by using sericin peptide to chelate the copper ions in phenol oxidase or tyrosinase - Google Patents

Abstract

Disclosed is an application of sericin peptide for inhibiting vegetable/fruit browning, including: separating sericin from fibroin in silk; keeping sericin and then using enzymes to hydrolyze sericin to be a peptide of micromolecules; performing a sterilization at high temperature; and then spraying or coating the sericin peptide solution on a cut surface of vegetable/fruit, the browning of vegetable/fruit caused by phenol oxidase or tyrosinase can be inhibited by using sericin peptide to chelate the copper ions in phenol oxidase or tyrosinase.

Description

The application of sericin peptides to inhibit browning of vegetables and fruits

The invention relates to an application for inhibiting browning of vegetables and fruits, in particular to spraying or applying sericin peptides to cut surfaces of vegetables and fruits to inhibit browning reaction of vegetables and fruits due to oxidation.

The browning reaction of foods is because the polyphenols contained in vegetables and fruits are oxidized and a condensation reaction occurs, turning into brown substances. For example, cut apples, lotus roots, or potatoes, etc. This phenomenon is unfavorable to food processors. The key enzyme causing this reaction is tyrosinase, which is a phenolic oxidase. The active center of this enzyme is two divalent copper ions. When copper ions are oxidized by contact with oxygen in the air, they will be on the surface of vegetables and fruits. It forms brown, and the darker the color over time, this will affect the appearance of vegetables and fruits, which is uncomfortable for food manufacturers.

It is known to chelate copper ions in tyrosinase to inhibit this type of enzyme browning reaction. The current food processing industry's control of the enzyme-type browning reaction is mainly to add the chemical metal ion chelating agent "ethylene diamine tetraacetate disodium (EDTA Na ₂ )" or "ethylene diamine tetraacetate disodium calcium (EDTA CaNa ₂ )".

However, regardless of ethylene diamine tetraacetate disodium (EDTA Na ₂ ) or ethylene diamine tetraacetate disodium calcium (EDTA CaNa ₂ ), although it is a statutory food additive, it is always chemically synthesized and may also cause kidney failure, hypotension, Risk of symptoms such as shock and irregular heartbeat. Because these two chemical additives are surfactants, they can chelate or seize minerals and heavy metals in the blood, which may affect the balance of ions in the body.

The main proteins of natural silk are sericin and sericin. Sericin is the structural center of silk, and the viscous substance around it is sericin. Sericin accounts for about 20% to 30% of the total silk protein, is a water-soluble polymer protein, has good biodegradability, biocompatibility and metal chelating ability, so in the fields of cosmetics, medicine, food, etc. Potential application value.

The purpose of the present invention is to provide a sericin peptide solution as an application for inhibiting browning of vegetables and fruits, which includes using the strong chelating force of sericin peptide and metal to chelate copper ions in phenol oxidase or tyrosinase To suppress browning of vegetables and fruits.

To achieve the above purpose, the technical means is to use the different water solubility characteristics of sericin and fibroin in silk, extract the aqueous solution of sericin, and use enzymes to cut the protein into small molecule peptides, because it is used in For food, it needs to be made into sericin peptide solution after high temperature sterilization, and then sprayed or coated on the cut surface of vegetables and fruits, using the strong chelating force of sericin peptide and metal to chelate phenol oxidase or tyrosinase Copper ions to inhibit browning of vegetables and fruits. Because the molecular weight of the peptide is much smaller than that of the protein, and the stability to heat and acid is higher than that of the protein, the relative protein also has better solubility. Therefore, the sericin peptide liquid phase of the present invention has a better chelating effect than the protein .

In order to facilitate your examination committee to have a better understanding and understanding of the technical means and operation process of the present invention, here is an example with the drawings, detailed description is as follows.

As shown in FIG. 1, the present invention relates to a sericin peptide used for inhibiting browning of vegetables and fruits. The sericin peptide is extracted from silkworm silk. The steps include:

Step 1: Take a natural silk or a flat cocoon, wash it with high temperature clean water for several times, then degumming with high temperature reverse osmosis water for 40~70 minutes, preferably 60 minutes, then centrifuge or filter will not dissolve in water The fibroin is removed, and the sericin remains in the aqueous solution.

Step 2: Add the papain to the extracted sericin first, and shake at 40℃~60℃ for 6 hours for initial hydrolysis. The optimal hydrolysis temperature is 50℃. The amount of papain added in this step is 0.3%~0.7% of the volume of the product in step 1, the best is 0.5%, and the concentration of papain is 8~12 units/mg, the best is 10 units/mg.

Step 3: In step 2, add papain at a volume ratio of 0.5%~1.0%, and shake at 40℃~60℃ for 6 hours for advanced hydrolysis. The optimal hydrolysis temperature is 50℃.

Step 4: Since fibroin is insoluble in water, centrifugation or filtration is used to remove the fibroin remaining in the product of step 3.

Step 5: Add 0.5% to 1% Alcalase in a volume ratio of 0.5 unit/ml to 1.5 unit/ml and shake at 45°C for 6 hours for complete hydrolysis. The optimal concentration of alkaline protease is 1 unit/ml.

Step 6: The high-temperature sterilization of the product of Step 5 is performed, and the activity of the added protease is removed, and the reaction is stopped.

Step 7: The product after sterilization in Step 6 is the sericin peptide solution of the present invention, which can be used directly, or stored at low temperature, frozen and dried.

Step 8: Dissolve the dried and preserved sericin peptide powder in sterile water to form sericin peptide solution, which can be sprayed or applied to the cut surface of vegetables and fruits to chelate phenolic oxidase or tyrosinase Copper ion, to inhibit the browning of vegetables and fruits.

The high temperature in step 1 refers to 80°C to 100°C, where the washed portion is preferably 90°C, and the reverse osmosis water degumming portion is added at 100°C.

Steps 2 and 3 can be repeated multiple times depending on the degree of hydrolysis of sericin into peptides.

The use concentration of the sericin peptide solution used in the present invention may be up to 2 μg/ml.

After the sericin peptide liquid of the present invention is sprayed or applied to the cut surface of vegetables and fruits, it will replace the oxygen in the air and chelate with the copper ions of phenol oxidase or tyrosinase, so the copper ions will not be oxidized, so the fruits and vegetables No browning reaction will occur on the cut surface. Moreover, sericin peptides are originally natural products. After taking vegetables and fruits coated with sericin peptides, their sericin peptides will be decomposed into amino acids in the small intestine. After being absorbed, they can be supplemented with natural amino acids to further synthesize the human body. The protein you need.

The component that can inhibit browning of vegetables and fruits of the present invention is a small molecule sericin peptide. First, the molecular weight of the peptide is smaller than that of protein, so it is easier to be absorbed after entering the human body. Second, the ratio of winning state to protein has higher heat and acid stability. Next, the solubility of peptides is also better than that of proteins. Since the present invention is applied to food, although silk is a natural product, it may be exposed to some germs during the process of obtaining and manufacturing sericin peptides. For food safety, the sericin liquid of the present invention needs to be sterilized at high temperature . If protein is used as an inhibitor, the protein will lose its activity due to denaturation during the high-temperature sterilization process, and then lose the function of chelating copper ions. For this reason, the present invention uses sericin peptides.

However, the above are only preferred embodiments of the present invention, which should not be used to limit the scope of implementation of the present invention; therefore, simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the invention description , Should still fall within the scope of this invention patent.

Figure 1 is a block flow diagram of the present invention.

Claims (4)

A sericin peptide is used as an application for inhibiting browning of vegetables and fruits. It contains a sericin peptide solution sprayed and/or coated on the cut surface of vegetables and fruits to chelate the copper ion of tyrosinase in vegetables and fruits, thereby inhibiting the browning reaction of vegetables and fruits , Where the sericin peptide liquid system is produced by the following steps: Step 1: Take a natural silk or a flat cocoon, wash it with clean water at high temperature several times, and then degumme it with reverse osmosis water at 80℃ to 100℃ 40 ~70 minutes, then remove the insoluble silk fibroin and retain the sericin dissolved in the aqueous solution; Step 2: Add the papain (Papain) of 0.3%~0.7% of the product volume of step 1 at 40℃~60℃ Shake for preliminary hydrolysis for 6 hours, the concentration of the papain used is 8~12 units/mg; Step 3: In step 2, add the papain of 0.5%~1.0% by volume, and shake at 40℃~60℃ for 6 hours For advanced hydrolysis, this step can be repeated multiple times depending on the degree of hydrolyzed sericin into peptides; Step 4: Use centrifugation or filtration to remove the residual fibroin in the product of Step 3; Step 5: Add a volume ratio of 0.5%~1 % Alcalase, whose concentration is 0.5 unit/ml ~ 1.5 unit/ml, shaken at 45℃ for 6 hours for complete hydrolysis, of which the optimal concentration of alkaline protease is 1 unit/ml; Step 6: Step 5: The product is sterilized at high temperature, and the activity of the added protease is removed to stop its reaction; and Step 7: The product after step 6 sterilization is the sericin peptide solution of the present invention, which is diluted to a concentration not greater than 2 μg/ml It can be sprayed or coated on the surface of vegetables and fruits as a browning inhibitor. The sericin peptide as described in item 1 of the patent application scope is used for inhibiting browning of vegetables and fruits, wherein the washing temperature in step 1 is preferably 90°C. The sericin peptide as described in item 1 of the patent application scope is used for inhibiting browning of vegetables and fruits, and the concentration of papain is preferably 10 units/mg. The sericin peptide described in item 1 of the patent application scope is used as an application for inhibiting browning of vegetables and fruits, in which the optimal hydrolysis temperature is 50°C.

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