阅读说明：本技术 一种甜菊糖苷的制备方法 (Preparation method of stevioside ) 是由 叶艳 于 2019-10-04 设计创作，主要内容包括：本发明提出了一种甜菊糖苷的制备方法,包括以下步骤：将一定质量的优质干燥甜叶菊叶片依次经过粉碎、浸提、层析、洗脱、纳滤、脱盐、喷雾干燥后制得甜菊糖苷；本发明改变了甜菊糖苷的传统生产工艺,节省了生产成本及周期,提高了产品质量,减少了废水对环境的污染。(The invention provides a preparation method of stevioside, which comprises the following steps: sequentially crushing, leaching, carrying out chromatography, eluting, nano-filtering, desalting and spray drying on high-quality dried stevia leaves with certain mass to prepare stevioside; the invention changes the traditional production process of stevioside, saves the production cost and the production period, improves the product quality and reduces the pollution of waste water to the environment.)

1. A method for preparing stevioside is characterized by comprising the following steps:

1) crushing the leaves: pulverizing the screened high-quality dried stevia rebaudiana leaves, and sieving with a 40-80 mesh sieve to obtain stevia rebaudiana powder;

2) preparing a leaching solution: soaking the stevia rebaudiana powder prepared in the step 1) in pure water with the mass of 5-7 times of that of the stevia rebaudiana powder for 2-5 hours, and filtering to obtain a leaching solution; repeating the above method for 1-2 times, mixing the leaching solutions obtained after 2-3 times of filtration, ultrafiltering, and nanofiltering to obtain concentrated leaching solution;

3) chromatography: putting the concentrated leaching liquor obtained in the step 2) into a resin chromatographic column, controlling the volume ratio of the concentrated leaching liquor to the resin chromatographic column to be 3-4: 1, and controlling the concentrated leaching liquor to carry out chromatography at a flow rate of 1.5-2 times the volume of the chromatographic column to obtain a chromatographic solution;

4) and (3) elution: eluting the chromatographic solution in the step 3) by using 1BV pure water, and eluting by using ethanol at the flow rate of 1 hour and 1.5BV column volume for 1-2 hours;

5) preparing nano filtrate: collecting the eluent in the step 4), recovering ethanol by a concentrator, and performing ultrafiltration and nanofiltration to obtain nanofiltration solution;

6) desalting: adding pure water with the volume of 1.5-2 times that of the nano filtrate into the nano filtrate prepared in the step 5, and desalting with cation exchange resin to obtain a desalted nano filtrate;

7) spray drying: and (3) further dehydrating the desalted and nanofiltration liquid prepared in the step 6) through a nanofiltration membrane, and performing spray drying when the mass concentration of nanofiltration liquid reaches 1.1-1.4mol/L to prepare stevioside.

2. The method of claim 1, wherein the method comprises the following steps: the temperature of the pure water in the step 2) is 40-50 ℃.

3. The method of claim 1 or 2, wherein the method comprises the following steps: and (3) ultrafiltering the filtrate in the step 2) by using an 15000-.

4. The method of claim 1, wherein the method comprises the following steps: and 5) respectively performing ultrafiltration on the washing liquid by an ultrafiltration membrane with the molecular weight of 8000-.

5. The method of claim 3, wherein the method comprises the following steps: and 5) respectively carrying out ultrafiltration on the eluent in the step 5) by an ultrafiltration membrane with 8000-.

6. The method of claim 1, wherein the method comprises the following steps: the cation exchange resin in the step 6) is 732 ion exchange resin or 717 ion exchange resin.

7. The method of claim 1, wherein the method comprises the following steps: the spray drying method in the step 7) adopts centrifugal spray drying.

Technical Field

The invention relates to the technical field of stevioside extraction, and particularly relates to a preparation method of stevioside.

Background

Stevia rebaudiana, also known as stevia rebaudiana and Glycyrrhiza uralensis, belongs to the family Compositae and is a evergreen shrub native to the higher plant of Paraguay, south America. Stevia rebaudiana contains 14 trace elements and 32 nutrient components, is not metabolized, accumulated, carcinogenic and toxic in the body, has the safety approved by organizations such as international FAO and WHO and American FAD, and the like, and thus is an excellent sugar source and a good nutrient source. Stevioside is an effective component in stevia rebaudiana and belongs to a natural high-power sweetener with low calorie. Research shows that stevioside has the characteristics of high sweetness, low calorie and no obvious toxic or side effect, can inhibit hyperglycemia and hypertension, and has the functions of diminishing inflammation, resisting tumors, relieving diarrhea and promoting urination and assisting immune regulation.

The traditional extraction processes of stevioside in industrial production comprise a hot water extraction method, a dialysis method, an enzyme method, a supercritical carbon dioxide extraction method, an ultrahigh pressure method, a reflux extraction method, a counter-current method and the like, but the traditional extraction processes often have the defect of low extraction rate.

For example, one existing method for preparing steviol glycosides is: soaking stevia powder in 15 times of 5% methanol water, filtering, resin exchange adsorbing, ethanol resolving, concentrating to remove alcohol, diluting, decolorizing, concentrating, and spray drying to obtain stevioside; the method has complicated process steps and increases environmental pollution.

Disclosure of Invention

The invention provides a preparation method of stevioside, which changes the traditional production process of stevioside, saves the production cost and the production period, improves the product quality and reduces the pollution of waste water to the environment.

The technical scheme adopted by the invention for solving the problems is as follows: a method for preparing stevioside comprises the following steps:

1) crushing the leaves: pulverizing the screened high-quality dried stevia rebaudiana leaves, and sieving with a 40-80 mesh sieve to obtain stevia rebaudiana powder;

2) preparing a leaching solution: soaking the stevia rebaudiana powder prepared in the step 1) in pure water with the mass of 5-7 times of that of the stevia rebaudiana powder for 2-5 hours, and filtering to obtain a leaching solution; repeating the above method for 1-2 times, mixing the leaching solutions obtained after 2-3 times of filtration, ultrafiltering, and nanofiltering to obtain concentrated leaching solution;

3) chromatography: putting the concentrated leaching liquor obtained in the step 2) into a resin chromatographic column, controlling the volume ratio of the concentrated leaching liquor to the resin chromatographic column to be 3-4: 1, and controlling the concentrated leaching liquor to carry out chromatography at a flow rate of 1.5-2 times the volume of the chromatographic column to obtain a chromatographic solution;

4) and (3) elution: eluting the chromatographic solution in the step 3) by using 1BV pure water, and eluting by using ethanol at the flow rate of 1 hour and 1.5BV column volume for 1-2 hours;

5) preparing nano filtrate: collecting the eluent in the step 4), recovering ethanol by a concentrator, and performing ultrafiltration and nanofiltration to obtain nanofiltration solution;

6) desalting: adding pure water with the volume of 1.5-2 times that of the nano filtrate into the nano filtrate prepared in the step 5, and desalting with cation exchange resin to obtain a desalted nano filtrate;

7) spray drying: and (3) further dehydrating the desalted and nanofiltration liquid prepared in the step 6) through a nanofiltration membrane, and performing spray drying when the mass concentration of nanofiltration liquid reaches 1.1-1.4mol/L to prepare stevioside.

Preferably, the temperature of the pure water in the step 2) is 40-50 ℃.

Preferably, the filtrate obtained in the step 2) is subjected to ultrafiltration by an ultrafiltration membrane with molecular weight of 15000-.

Preferably, the eluent in the step 5) is respectively subjected to ultrafiltration by an ultrafiltration membrane with a molecular weight of 8000-.

Preferably, the cation exchange resin in the step 6) is 732 or 717 ion exchange resin.

Preferably, the spray drying method in step 7) adopts centrifugal spray drying.

The invention has the beneficial effects that: the traditional production process of stevioside is changed, and the production cost and the production period are saved; the ethanol is used for resolution, so that the production cost is reduced, the pollution caused by introducing other organic solvents is avoided, the safety of stevioside production and the product quality are improved, and the pollution of waste water to the environment is reduced.

Detailed Description

The present invention is further illustrated by the following examples.