阅读说明：本技术 一种提取棉子糖的方法 (Method for extracting raffinose ) 是由 曹通 蔡亚园 田洪 于 2019-10-28 设计创作，主要内容包括：本发明公开了一种提取棉子糖的方法,以脱脂棉粕为原料,使用有机溶剂水溶液萃取脱酚,得到脱酚棉籽蛋白和脱酚液,然后从脱酚液中提取棉子糖,其中,有机溶剂水溶液为低浓度弱碱性有机溶剂水溶液,本发明具有操作简单、原料易得、成本较低、污染小、对设备要求低、适合工业化大规模生产的优点。(The invention discloses a method for extracting raffinose, which takes defatted cottonseed meal as a raw material, uses an organic solvent aqueous solution for extraction and dephenolization to obtain dephenolized cottonseed protein and dephenolized solution, and then extracts the raffinose from the dephenolized solution, wherein the organic solvent aqueous solution is a low-concentration weak alkaline organic solvent aqueous solution.)

1. A method for extracting raffinose takes defatted cottonseed meal as a raw material, uses organic solvent aqueous solution to extract dephenolization to obtain dephenolized cottonseed protein and dephenolized liquid, and is characterized in that: extracting raffinose from the dephenolized solution, wherein the organic solvent aqueous solution is low-concentration weak alkaline organic solvent aqueous solution.

2. The method of claim 1, wherein the raffinose is extracted from the group consisting of: the method comprises the following steps:

A. extracting dephenolization by using a low-concentration weak alkaline organic solvent aqueous solution by using defatted cottonseed meal as a raw material to obtain dephenolized cottonseed protein and dephenolized liquid;

B. filtering the dephenolized liquid by a nanofiltration membrane to remove macromolecular impurities to obtain a permeate;

C. passing the permeate through a solid phase extraction column, leaching with an organic solvent, and eluting with deionized water to obtain an eluent;

D. decolorizing the eluent;

E. and D, concentrating the decolorized solution obtained in the step D, slowly stirring, cooling, crystallizing and washing crystals to obtain the raffinose with the purity of more than or equal to 98%.

3. The method of claim 2, wherein the raffinose is extracted from the group consisting of: the material-liquid ratio in the extraction in the step A is 1: 1-20, and the organic solvent in the low-concentration weak-alkaline organic solvent aqueous solution is any one or more of acetone, butanone, methanol and diethyl ether.

4. A method of extracting raffinose as claimed in claim 3, wherein: the mass ratio of the organic solvent to water in the low-concentration weak alkaline organic solvent aqueous solution is 1-8: 1, the concentration of the alkaline acetone aqueous solution is less than or equal to 50%, the concentration of the alkaline butanone aqueous solution is less than or equal to 50%, the concentration of the alkaline methanol aqueous solution is less than or equal to 60%, and the concentration of the alkaline ether aqueous solution is less than or equal to 55%.

5. The method of claim 2, wherein the raffinose is extracted from the group consisting of: and the pH value of the low-concentration weak alkaline organic solvent aqueous solution in the step A is 7.5-9.0.

6. The method of claim 2, wherein the raffinose is extracted from the group consisting of: and the intercepted molecular weight of the nanofiltration membrane in the step B is more than or equal to 505 Da.

7. The method of claim 2, wherein the raffinose is extracted from the group consisting of: and C, filling materials in the solid phase extraction column in the step C are ion exchange type or adsorption type materials.

8. A method of extracting raffinose as claimed in claim 3, wherein: the organic solvent in the step C is the same as the organic solvent in the step A.

9. The method of claim 2, wherein the raffinose is extracted from the group consisting of: and D, decoloring by adopting active carbon or anion exchange resin.

10. The method of claim 2, wherein the raffinose is extracted from the group consisting of: and E, concentrating the decolorized solution in the step E until the content of the raffinose is 15-35%, and cooling and crystallizing at the temperature of less than or equal to 15 ℃.

Technical Field

The invention relates to a method for extracting raffinose, in particular to a process for extracting the raffinose from a cottonseed meal dephenolization liquid.

Background

Dephenolized cottonseed protein is a protein product obtained by removing cotton linters, peeling, leaching at low temperature to extract oil, leaching with an organic solvent to remove gossypol, drying and crushing, the protein content of the cottonseed protein can reach more than 50%, and the cottonseed protein is a high-quality protein resource. The cottonseed meal is a flour cake obtained by squeezing the cottonseed, and most of residual oil in the cottonseed meal is separated by a leaching process to obtain a reddish or yellow granular article. In the prior art, defatted cottonseed meal is generally used as a raw material, and dephenolization is carried out by using an organic solvent aqueous solution to obtain dephenolized cottonseed protein. Wherein, when the organic solvent is used for removing the gossypol, a part of raffinose can be extracted, and the traditional processing technology of the dephenolized cottonseed protein only recycles the solvent in the dephenolized liquid and then recycles the solvent, thereby causing waste of raffinose resources.

Raffinose is a functional oligosaccharide having a strong action of proliferating bifidobacteria, has the effects of promoting proliferation of beneficial bacteria in human intestinal tracts, preventing food browning, keeping skin moist and the like, and is widely applied to industries such as food, medicine, cosmetics and the like at present. In developed countries such as japan and the usa, consumers have high recognition and acceptance. It is known that the annual average growth rate of major oligosaccharide varieties in Japan exceeds 14%, and the market consumption of raffinose exceeds 500 tons. The raffinose is widely present in seeds of many vegetables, fruits, rice and oil crops in nature, wherein the content of the cottonseed kernels is the highest and can reach 4-5%, and the degreased cottonseed meal contains about 4.2% of the raffinose and is a rich source of the raffinose.

Patent document CN 101390583B discloses a method for extracting raffinose from cottonseed meal, which comprises extracting cottonseed meal with ethanol solution for 3-5 times, concentrating the extractive solution, decolorizing with activated carbon, crystallizing, and recrystallizing for multiple times to obtain final product of raffinose. The method is simple to operate, has low equipment requirement, needs repeated recrystallization to improve the purity of the raffinose, and has low efficiency, high cost and low yield of the raffinose.

Patent document CN 101372498B, "a process for preparing high-purity raffinose from defatted cottonseed meal", discloses a process for extracting raffinose from defatted cottonseed meal, which comprises extracting defatted cottonseed meal with methanol or ethanol, decolorizing and removing impurities with fixed bed, and crystallizing step by step to obtain raffinose. The raffinose obtained by the process has high purity and high yield, but in actual operation, the activated carbon and the resin for decoloring and impurity removal need to be frequently replaced or regenerated, the operation is complicated by using a fixed bed, the cost is high, and the efficiency is low.

Patent document CN 102070677 a, "a refining method of raffinose", also uses methanol or ethanol to extract defatted cottonseed meal, and then obtains raffinose crystals by cooling and fractional crystallization, the process is simple and convenient to operate, but the purity of the obtained raffinose crystals can only reach more than 85%, and the crystallization time is long.

In addition, the three processes adopt high-concentration methanol or ethanol to extract cottonseed meal or degreased cottonseed meal, and then decolor, remove impurities and crystallize through active carbon or resin to obtain raffinose crystals. In order to ensure the dephenolization effect, a high-concentration organic solvent is required to be used, so that the solubility of raffinose in the raffinose is very low and generally cannot exceed 2%, the yield of the raffinose extracted and recovered from the raffinose is low, and simultaneously, the protein in the cottonseed meal is denatured, so that the dephenolized cottonseed protein in the cottonseed meal cannot be recovered or utilized, and the waste of protein resources is caused.

In summary, in order to fully utilize the protein resource and raffinose resource in the cottonseed meal and obtain high-purity raffinose, a raffinose extraction process with easily available raw materials, simplified process flow, high yield and low production cost needs to be developed.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for extracting raffinose, which can recover the raffinose on the premise of ensuring that protein in cottonseed meal is not denatured, and has high yield and high purity.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a method for extracting raffinose comprises using defatted cottonseed meal as raw material, extracting with organic solvent water solution for dephenolization to obtain dephenolized cottonseed protein and dephenolized solution, and extracting raffinose from the dephenolized solution, wherein the organic solvent water solution is low-concentration weak alkaline organic solvent water solution.

The technical scheme of the invention is further improved as follows: the method comprises the following steps:

A. extracting dephenolization by using a low-concentration weak alkaline organic solvent aqueous solution by using defatted cottonseed meal as a raw material to obtain dephenolized cottonseed protein and dephenolized liquid;

B. filtering the dephenolized liquid by a nanofiltration membrane to remove macromolecular impurities to obtain a permeate;

C. passing the permeate through a solid phase extraction column, leaching with an organic solvent, and eluting with deionized water to obtain an eluent;

D. decolorizing the eluent;

E. and D, concentrating the decolorized solution obtained in the step D, slowly stirring, cooling, crystallizing and washing crystals to obtain the raffinose with the purity of more than or equal to 98%.

The technical scheme of the invention is further improved as follows: the material-liquid ratio in the extraction in the step A is 1: 1-20, and the organic solvent in the low-concentration weak-alkaline organic solvent aqueous solution is any one or more of acetone, butanone, methanol and diethyl ether.

The technical scheme of the invention is further improved as follows: the mass ratio of the organic solvent to water in the low-concentration weak alkaline organic solvent aqueous solution is 1-8: 1, the concentration of the alkaline acetone aqueous solution is less than or equal to 50%, the concentration of the alkaline butanone aqueous solution is less than or equal to 50%, the concentration of the alkaline methanol aqueous solution is less than or equal to 60%, and the concentration of the alkaline ether aqueous solution is less than or equal to 55%.

The technical scheme of the invention is further improved as follows: and the pH value of the low-concentration weak alkaline organic solvent aqueous solution in the step A is 7.5-9.0.

The technical scheme of the invention is further improved as follows: and the intercepted molecular weight of the nanofiltration membrane in the step B is more than or equal to 505 Da.

The technical scheme of the invention is further improved as follows: and C, filling materials in the solid phase extraction column in the step C are ion exchange type or adsorption type materials.

The technical scheme of the invention is further improved as follows: the organic solvent in the step C is the same as the organic solvent in the step A.

The technical scheme of the invention is further improved as follows: and D, decoloring by adopting active carbon or anion exchange resin.

The technical scheme of the invention is further improved as follows: and E, concentrating the decolorized solution in the step E until the content of the raffinose is 15-35%, and cooling and crystallizing at the temperature of less than or equal to 15 ℃.

Due to the adoption of the technical scheme, the invention has the technical progress that:

the method for extracting the raffinose from the defatted cottonseed meal has the advantages of simple operation, easily obtained raw materials, lower cost, small pollution, low requirement on equipment and suitability for industrial large-scale production. The raffinose content in the dephenolizing solution is about 4%, so that the raffinose in the cottonseed meal is almost completely dissolved in the dephenolizing solution (in the existing raffinose extraction process, the raffinose content in the dephenolizing solution generally does not exceed 2%), the raffinose is extracted and recovered from the dephenolizing solution, the yield and the purity are high, meanwhile, the protein denaturation in the cottonseed meal cannot be caused, and the utilization of the dephenolized cottonseed protein cannot be influenced.

The method adopts the low-concentration weak alkaline organic solvent aqueous solution for dephenolizing treatment, reduces the concentration, increases the extraction rate of the raffinose, enables the raffinose content in the dephenolized solution to be increased to about 4%, simultaneously adjusts the pH value of the dephenolized solution to 7.5-9.0, enables the gossypol to be converted into water-soluble gossypol salt under the weak alkaline condition, ensures the removal effect of the gossypol, and simultaneously can not cause the protein in the cottonseed meal to be denatured.

According to the invention, the nanofiltration membrane is adopted for filtering, so that macromolecular impurities in the dephenolized liquid can be effectively filtered and removed, the influence of the macromolecular impurities on subsequent crystallization is eliminated, meanwhile, the intercepted molecular weight of the nanofiltration membrane is limited to be larger than or equal to 505Da, the filtering rate can be ensured while the filtering and removing of the macromolecular impurities with larger influence is ensured, and the production efficiency is improved.

The filler in the solid phase extraction column is an ion exchange type or adsorption type material, so that the impurity sugar of monosaccharide, disaccharide and other non-raffinose can be effectively removed, elution is carried out for two times, an organic solvent is used firstly, then deionized water is used, the impurity removal efficiency can be ensured, the organic solvent is consistent with the organic solvent in the dephenolization process, and no new impurity is introduced.

Detailed Description

The present invention will be described in further detail with reference to the following examples:

a method for extracting raffinose comprises extracting and dephenolizing defatted cottonseed meal with organic solvent water solution to obtain dephenolized cottonseed protein and dephenolized solution, and extracting raffinose from the dephenolized solution. Wherein the organic solvent aqueous solution is a low-concentration weak alkaline organic solvent aqueous solution which can not cause the dephenolized cottonseed protein to be denatured.

The method comprises the following specific steps:

A. extracting dephenolization by using a low-concentration weak alkaline organic solvent aqueous solution by using defatted cottonseed meal as a raw material to obtain dephenolized cottonseed protein and dephenolized liquid;

wherein the material-liquid ratio during extraction is 1: 1-20, the mass ratio of the organic solvent to water in the low-concentration weak alkaline organic solvent aqueous solution is 1-8: 1, the pH value is 7.5-9.0, the organic solvent in the low-concentration weak alkaline organic solvent aqueous solution is any one or more of acetone, butanone, methanol and diethyl ether, the concentration of the alkaline acetone aqueous solution is less than or equal to 50%, the concentration of the alkaline butanone aqueous solution is less than or equal to 50%, the concentration of the alkaline methanol aqueous solution is less than or equal to 60%, and the concentration of the alkaline diethyl ether aqueous solution is less than or equal to 55%.

B. Filtering the dephenolized liquid by a nanofiltration membrane to remove macromolecular impurities to obtain a permeate;

wherein the intercepted molecular weight of the nanofiltration membrane is more than or equal to 505 Da;

C. passing the permeate through a solid phase extraction column, leaching with an organic solvent, and eluting with deionized water to obtain an eluent;

wherein, the filler in the solid phase extraction column is an ion exchange type or adsorption type material, and the organic solvent is consistent with the organic solvent in the step A;

D. decolorizing the eluent;

wherein the decolorization is carried out by using activated carbon or anion exchange resin

E. And D, concentrating the decolorized solution obtained in the step D until the content of the raffinose is 15-35%, slowly stirring, cooling and crystallizing at the temperature of less than or equal to 15 ℃, and washing crystals to obtain the raffinose with the purity of more than or equal to 98%.