A method for obtaining grape seed oligomers

Abstract

The application discloses a preparation method of grape seed oligomer, which comprises the following steps: dissolving raw material containing high polymer procyanidin in water, adding a nucleophilic reagent, heating to boiling, refluxing for not less than 30 minutes, cooling to 25 DEG C, adding 95% ethanol, stirring uniformly, passing through a macroporous resin column, eluting with 30% ethanol, collecting the eluent and 30% ethanol eluent, and obtaining a grape seed oligomer solution. The high polymer procyanidin and the nucleophilic reagent are heated and reacted together, the polymerization bond of the high polymer procyanidin can be broken under the attack of the nucleophilic reagent, so that the degradation is achieved, the content of the obtained low polymer procyanidin is high, the average polymerization degree of the high polymer procyanidin is reduced from 13 to 3, and the recovery rate of the low polymer procyanidin is high and can reach more than 99%.

Description

TECHNICAL FIELD

[0001] The present application relates to grape seed oligomers, and in particular to a method for preparing grape seed oligomers. BACKGROUND

[0002] Proanthocyanidin is a general term for flavan-3-ol or flavan-3,4-ol derivatives that are widely present in plants. In the field of phytochemistry, proanthocyanidin refers to all substances that can produce anthocyanidin under the treatment of hot acid, and it includes monomeric proanthocyanidin and polymeric proanthocyanidin. Monomeric proanthocyanidin corresponds to flavan-4-ol and flavan-3,4-ol, and polymeric proanthocyanidin corresponds to condensed tannin, red powder and phenolic acid.

[0003] Polymeric proanthocyanidin is a new type of health care product and medicine that has been increasingly popular among the public in recent years. It has extremely strong antioxidant properties, and also shows outstanding effects in terms of antiviral and anticancer properties. Proanthocyanidin polymers are widely present in plants in nature, and are the main effective components of plant defense systems, and are also the main active components of many Chinese herbal medicines.

[0004] At present, there are many mature technologies for extracting, separating and purifying oligomeric proanthocyanidin from plants such as grape seeds, pine bark and ginkgo leaves. However, most of the proanthocyanidin in plants exists in the form of high polymers, for example, the content of proanthocyanidin with a degree of polymerization greater than 5 in grape seeds is as high as 65%, and the antioxidant activity of high polymer proanthocyanidin is much lower than that of oligomers. Therefore, most of the high polymer proanthocyanidin separated from oligomers can only be used as a low-value byproduct such as a natural pigment.

[0005] If the procyanidins high polymer material can be effectively degraded into oligomers, and its potential antioxidant activity is exerted, it will undoubtedly have far-reaching significance for improving the utilization rate of natural resources and the added value of procyanidin products. ZL200410016355.6 provides a kind of oligomer procyanidin and preparation method, which is a method for obtaining oligomer procyanidin by oxidative degradation. The oligomer procyanidin is 2-4 polymer, and condensed tannin is used as raw material. Hydrogen peroxide or potassium chlorate with a concentration of 20-60% is used as oxidizing agent to oxidize and degrade the condensed tannin, and then the oligomer procyanidin is obtained by separation and purification. ZL200710067047.X provides a preparation method of oligomer procyanidin, which belongs to acid degradation method. The high polymer procyanidin is used as raw material to prepare oligomer procyanidin under acidic conditions. In addition to the above two methods, there are hydrogenation degradation method and sulfite method. Although the above methods can prepare oligomer procyanidin with high purity, there are still disadvantages. Among them, the hydrogen peroxide or potassium chlorate used as oxidizing agent in the oxidative degradation method is unstable and easy to decompose, which can cause product inactivation and low product yield. The acid degradation method pollutes the environment and damages the equipment. The hydrogenation degradation method requires high temperature and high pressure. The sulfite method has a long production cycle, which makes the whole process energy-consuming, high-cost, unsafe and not environmentally friendly. SUMMARY

[0006] The present application provides a preparation method for obtaining grape seed oligomers.

[0007] The technical scheme provided by the present application is: a preparation method for obtaining grape seed oligomers. The raw material containing high polymer procyanidins is dissolved in water, a nucleophilic reagent is added, heated to boiling, refluxed for not less than 30 minutes, then cooled to 25 DEG C, 95% ethanol is added, stirred uniformly, then passed through a macroporous resin column, eluted with 30% ethanol, and the effluent and 30% ethanol eluent are collected to obtain a grape seed oligomer solution.

[0008] The raw material containing high polymer procyanidins can be obtained from the dry powder obtained by chromatography and high alcohol elution of grape seeds. In an embodiment of the present application, the content of high polymer procyanidins is not less than 50%, and the polymerization degree of high polymer procyanidins is 11.5-13.5.

[0009] The nucleophilic reagent is tea polyphenol, which can be directly used, or green tea extract containing 95% tea polyphenol can be used.

[0010] In the present application, the mass ratio between the raw material containing high polymer procyanidins and the nucleophilic reagent is 20:1-20:1.5.

[0011] The heating reflux extraction time is preferably 30 minutes.

[0012] The macroporous resin is selected from LX-19B resin.

[0013] The present application has the following advantages:

[0014] 1. The present application adopts high polymerization procyanidins and nucleophilic reagents to heat and react together, and the polymerization bond of the high polymerization procyanidins can be broken under the attack of the nucleophilic reagents, so as to achieve degradation.

[0015] 2. The product obtained by the aspect provided by the present application has high oligomeric procyanidin content, the average polymerization degree of the high polymerization procyanidins is reduced from 13 to 3, and the recovery rate of the oligomeric procyanidins is high, which can reach more than 99%.

[0016] 3. The present application expands the use range of grape seed products.

[0017] 4. The process of the present application is stable, suitable for mass production, uses a small amount of ethanol and water in the whole process, and has little solvent residue in the produced product, which is safe and environmentally friendly. DETAILED DESCRIPTION

[0018] The present application will be further described below in combination with specific examples.

[0019] Example 1

[0020] Take 100g of dry powder of grape seeds eluted by column chromatography with a high degree, which has a polymerization degree of 13 and a procyanidin content of 50%, dissolve it in 300g of purified water, add 5g of green tea extract (95% tea polyphenol), heat to boiling, reflux extraction for 30 minutes, cool to 25 degrees, add 100ML of 95% ethanol, stir uniformly, and then put into 200g of LX-19B resin which has been treated (the resin is first put into the column with 400ml of 30% ethanol), after the completion of the feeding, use 200ML of 30% ethanol for elution. Collect the effluent and the eluent of 30% ethanol, concentrate to no alcohol, and spray dry. 48g of product is obtained, which has a polymerization degree of 3 and a procyanidin content of 99.1% detected by HPLC.

[0021] Comparative Example 1

[0022] Take 100g of dry powder of grape seeds eluted by column chromatography with a high degree, which has a polymerization degree of 13 and a procyanidin content of 50%, dissolve it in 300g of purified water, add 5g of green tea extract (95% tea polyphenol), heat to 80 degrees, reflux extraction for 30 minutes, cool to 25 degrees, add 100ML of 95% ethanol, stir uniformly, and then put into 200g of LX-19B resin which has been treated (the resin is first put into the column with 400ml of 30% ethanol), after the completion of the feeding, use 200ML of 30% ethanol for elution. Collect the effluent and the eluent of 30% ethanol, concentrate to no alcohol, and spray dry. 48g of product is obtained, which has a polymerization degree of 3 and a procyanidin content of 99.1% detected by HPLC.

Claims

1. A method for obtaining grape seed oligomers, characterized in that, Dissolve the raw material containing high polymer procyanidin in water, add a nucleophilic reagent, heat to boiling, reflux extraction for not less than 30 minutes, then cool to 25℃, add 95% ethanol, stir uniformly, then pass through a macroporous resin column, elute with 30% ethanol, collect the effluent and 30% ethanol eluate, and grape seed oligomer solution is obtained; the content of high polymer procyanidin in the raw material containing high polymer procyanidin is not less than 50%, and the polymerization degree of high polymer procyanidin is 11.5-13.5; the nucleophilic reagent is tea polyphenol.

2. The method for preparing grape seed oligomers according to claim 1, characterized in that, The tea polyphenol is from green tea extract containing 95% tea polyphenol.

3. The method of claim 1, wherein the preparation of the grape seed oligomers is characterized by, The mass ratio between the raw material containing high polymer procyanidin and the nucleophilic reagent is 20:1-20:1.

5.

4. The method of claim 1, wherein the preparation of the grape seed oligomers is characterized by, The heating reflux extraction time is 30 minutes.

5. The method of claim 1, wherein the preparation of the grape seed oligomers is characterized by, The macroporous resin is LX-19B resin.