阅读说明：本技术 一种酶催化半合成制备罗汉果赛门苷的方法 (Method for preparing mogroside through enzyme catalysis semisynthesis ) 是由 李伟 黄华学 贺进军 黄�俊 宋谷良 江小龙 于 2021-07-23 设计创作，主要内容包括：本发明涉及一种酶催化半合成制备罗汉果赛门苷的方法,其特征在于,包括以下步骤：将包括罗汉果苷V和含有β-1,6糖苷键的葡聚糖或多糖的底物溶液中加入β-葡萄糖苷酶进行酶解得到罗汉果甜苷IIIE和β-葡萄糖残基的混合物,之后加入葡萄糖基转移酶进行反应,即得赛门苷。本发明高效的利用了β-葡萄糖苷酶；酶解罗汉果苷V和含有β-1,6糖苷键的葡聚糖或多糖,再在葡萄糖基转移酶作用下反应制备目标产品赛门苷,副反应少,转化率高。按照本发明方法,罗汉果甜苷V转化为罗汉果赛门苷的产率在90％以上。本发明方法工艺简单,可操作性强,设备要求低,反应条件温和,生产成本低,适宜于工业化生产。(The invention relates to a method for preparing grosvenor momordica siamenoside through enzyme catalysis semisynthesis, which is characterized by comprising the following steps: adding beta-glucosidase into substrate solution containing mogroside V and glucan or polysaccharide containing beta-1, 6 glycosidic bonds for enzymolysis to obtain a mixture of mogroside IIIE and beta-glucose residues, and then adding glucosyltransferase for reaction to obtain siamenoside. The invention efficiently utilizes beta-glucosidase; enzymolysis mogroside V and glucan or polysaccharide containing beta-1, 6 glycosidic bond, and then reaction under the action of glucosyltransferase to prepare the target product siamenoside, with less side reaction and high conversion rate. According to the method, the yield of the mogroside V converted into the mogroside is over 90 percent. The method has the advantages of simple process, strong operability, low equipment requirement, mild reaction condition and low production cost, and is suitable for industrial production.)

1. A method for preparing mogroside through enzyme catalysis semisynthesis is characterized by comprising the following steps: adding beta-glucosidase into substrate solution containing mogroside V and glucan or polysaccharide containing beta-1, 6 glycosidic bonds for enzymolysis to obtain a mixture of mogroside IIIE and beta-glucose residues, and then adding glucosyltransferase for reaction to obtain siamenoside.

2. The method of claim 1, comprising the steps of:

(1) preparation of a substrate solution: putting a substrate rich in mogroside V and an auxiliary substrate into a buffer solution with the pH of 5.8-6.5, heating, and stirring until the substrates are completely dissolved to obtain a substrate solution; the co-substrate is a glucan or polysaccharide containing beta-1, 6 glycosidic linkages;

(2) synthesizing mogroside IIIE: adding beta-glucosidase into the substrate solution, and carrying out heat preservation and stirring reaction to obtain a reaction solution I; heating the reaction solution I to inactivate enzyme, cooling to 5-10 ℃, centrifuging, and filtering to obtain filtrate A containing mogroside IIIE and active beta-glucose residue;

(3) the synthesis method of the mogroside comprises the following steps: adding glucosyltransferase into the filtrate A in the step (2), and stirring at a constant temperature until the reaction is complete to obtain a reaction solution II; heating the reaction liquid II to inactivate enzyme, cooling to room temperature, centrifuging, and filtering to obtain filtrate B containing mogroside;

(4) and (3) post-treatment: and (4) passing the filtrate B through a macroporous adsorption resin chromatographic column, washing with water, then washing with alcohol, and concentrating and drying the alcohol eluent to obtain a finished product of the mogroside.

3. The method according to claim 1 or 2, wherein the substrate Lo Han Guo gan V in step (1) is present in an amount of 50% or more, preferably 70% or more, more preferably 90% or more.

4. The method of claim 1 or 2, wherein the co-substrate of step (1) is at least one selected from the group consisting of a lycopin, laminarin, and yeast glucan, and the amount of co-substrate is 10-20% by weight of mogroside V in the substrate.

5. The method according to claim 2, wherein the buffer solution in step (1) is potassium dihydrogen phosphate-sodium hydroxide buffer solution with a concentration of 0.01-0.05mol/L, and the pH of the buffer solution is in the range of 5.8-6.5.

6. The method according to claim 1 or 2, wherein the concentration of β -glucosidase is 30-50u/mg and the concentration of glucosyltransferase is 3-10u/μ L.

7. A method according to claim 6, wherein the β -glucosidase is present in an amount of 0.5% to 3% by weight of mogroside V in the substrate and/or the glucosyltransferase is present in an amount of 1% to 4% by weight of mogroside V in the substrate.

8. The method according to claim 1 or 2, characterized in that the enzymolysis reaction temperature is 55-65 ℃, and the reaction time is 8-15 h; the stirring speed during the reaction is 60-100 rpm.

9. The method according to claim 1 or 2, wherein the glucosyltransferase is added to the reaction under the conditions of 35-55 ℃ for 10-20h at 60-100 rpm.

10. The method as claimed in claim 2, wherein the macroporous adsorbent resin of step (4) is of a type comprising D101, AB-8, LX-T28 or HP 20.

Technical Field

The invention relates to a preparation method of mogroside, in particular to a method for preparing mogroside through enzyme catalysis semisynthesis.

Background

The momordica grosvenori is a specific plant in China, is mainly produced in the Lingui county and the Yongfu county in the Guilin city, is praised as the immortal fruit by people, and is a famous and precious Chinese medicinal material which is firstly published by the Ministry of health and can be used as medicine and food. Mogroside is a low-calorie, high-sweetness, non-nutritive, non-fermented sweetener, and is the main sweet component in momordica grosvenori. Mogroside as a sweetener is safe and nontoxic, does not affect blood sugar and induce dental caries, and can be used for various foods in an unlimited amount according to the national mandatory standard GB2760 food additive use standard. Under the current global initiative of sugar-free, low-sugar healthy diet, mogrosides has become a hot natural sweetener of major interest to various large food and beverage production enterprises.

The mogroside comprises mogroside IIIE, mogroside IV, siamenoside, mogroside V, mogroside VI and the like, and in the mature grosvenor momordica fruit, the mogroside V is the most main mogroside, but the mogroside V is not the highest sweetness, and the sweetness is 344 times of that of the cane sugar, namely 256 times of that of the cane sugar. Of all mogrosides, the sweet glycoside with the highest sweetness is siamenoside, which is also the sweet natural component in cucurbitane triterpenoid saponin found at present, and the sweetness of the mogroside is 563 times that of sucrose. However, the proportion of siamenoside in total mogrosides is very small (less than 5%). At present, the natural high-power sweetener based on the momordica grosvenori still takes the momordica grosvenori glycoside V as the most main component. It can be seen that the rarity of siamenoside severely hinders its widespread use. At present, an industrialization technology capable of efficiently converting mogroside V into siamenoside is urgently needed.

Mogroside V has the following structural formula:

the structural formula of siamenoside is as follows:

the chemical structure of siamenoside is one beta-D-glucose less than that of mogroside V, so that the cutting off of the glucose unit is a feasible method for obtaining siamenoside.

CN201811284733.7 discloses a method for improving mogroside sweetness, which adopts a fermentation method to modify the main component of mogroside, i.e. mogroside V, and converts the mogroside V into higher sweetness siamenoside by cutting off beta-D glucosyl on R1 bond, so as to improve the integral sweetness, controls the conversion rate by the fermentation method, further collects a target product by chromatographic chromatography, and finally, concentrates and freezes to obtain the product. The method does not definitely record the conversion rate of mogroside V from enzymolysis.

CN201911054996.3 discloses a method for improving the integral sweetness of mogroside based on the improvement of the siamenoside content, which comprises the steps of dissolving a mogroside product in a fermentation culture solution with the same concentration, sterilizing, inoculating a stock solution into the screened specific sake yeast CN01, naturally fermenting for 72 hours, centrifugally filtering, collecting a thallus-removed fermentation solution containing high-content siamenoside, purifying the fermentation solution by ion type chromatographic resin step by step, collecting a siamenoside enrichment section, concentrating and drying to obtain a finished product. . However, there are many questions to be asked about, and the patent first utilized the strains numbered Sc001, VSc01, CN01, CN01-A, T-CN00 and screened out specific sake yeast CN01 and prepared the fermentation broth thereof, but these strains did not disclose the accession numbers of microorganisms and could not confirm that the strains were obtained before the application date. Furthermore, the percentage by mass of the various sweet glycosides in this patent is an integer multiple of 10, which is not at all possible in the opinion of the person skilled in the art.

CN201410208095.6 discloses a method for preparing sweetener siamenoside I, which comprises the steps of taking fresh momordica grosvenori, dry fruit water extract or finished product water solution of commercial momordica grosvenori saponin V as raw materials, adding catalytic enzyme, reacting for 4-12 hours at 30-70 ℃, heating to boiling and inactivating for 3-5 minutes to obtain reaction liquid, eluting 3-5 column volumes or 80% ethanol for 2 column volumes by using fillers to adsorb saponin in the reaction liquid to obtain eluent, concentrating and drying the eluent to obtain siamenoside I. The patent discloses that the content of siamenoside I increases from 5% to 40% when 50 ten thousand U/L beta-glucanase is used as catalytic enzyme.

CN201210526355.5 discloses a method for preparing high-purity siamenoside I, but the method is actually the purification of siamenoside and does not convert the mogroside V into the siamenoside.

Disclosure of Invention

In the prior art, the mogroside V is prepared by mogroside V, so that a high requirement is provided for the specificity of enzymolysis, because a great amount of beta-D-glucose can be cleaved in the molecular structure of the mogroside V, the selectivity of beta-D-glucose cleavage needs to be improved for obtaining the mogroside with high yield, but the cost is high on one hand, the stability is not good enough on the other hand, and the selectivity of a microbial strain after being propagated for several generations can be reduced by a microbial enzyme screening mode generally. Therefore, the method is not suitable for converting the grosvenor momordica glycoside V into the siamenoside on a large industrial scale. The invention overcomes the defects of the prior art, provides a synthetic method of mogroside, which firstly converts the mogroside V into the mogroside IIIE, then reacts with the active beta-glucose residue generated by the enzymolysis of beta-glucan in the presence of beta-glucose transferase, and finally obtains the siamenoside with high yield and high purity.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method for preparing mogroside through enzyme catalysis semisynthesis comprises the following steps: adding beta-glucosidase into substrate solution containing mogroside V and glucan or polysaccharide containing beta-1, 6 glycosidic bonds for enzymolysis, and adding glucosyltransferase for reaction after enzymolysis to obtain siamenoside.

Further, the method for preparing the mogroside through enzyme-catalyzed semisynthesis comprises the following steps:

(1) preparation of a substrate solution: putting a substrate rich in mogroside V and an auxiliary substrate into a buffer solution with the pH of 5.8-6.5, heating, and stirring until the substrates are completely dissolved to obtain a substrate solution; the co-substrate is a glucan or polysaccharide containing beta-1, 6 glycosidic linkages;

(2) synthesizing mogroside IIIE: adding beta-glucosidase into the substrate solution, and carrying out heat preservation and stirring reaction to obtain a reaction solution I; heating the reaction solution I to inactivate enzyme, cooling to 5-10 ℃, centrifuging, and filtering to obtain filtrate A containing mogroside IIIE and active beta-glucose residue;

(3) the synthesis method of the mogroside comprises the following steps: adding glucosyltransferase into the filtrate A in the step (2), and stirring at a constant temperature until the reaction is complete to obtain a reaction solution II; heating the reaction liquid II to inactivate enzyme, cooling to room temperature, centrifuging, and filtering to obtain filtrate B containing mogroside;

(4) and (3) post-treatment: and (4) passing the filtrate B through a macroporous adsorption resin chromatographic column, washing with water, then washing with alcohol, and concentrating and drying the alcohol eluent to obtain a finished product of the mogroside.

The invention has the advantages that the enzyme adopted by the invention is the conventional commercially available beta-glucosidase and glucosyltransferase, the process condition is simple, the raw material is cheap and easy to obtain, and the method is suitable for large-scale industrial production of siamenoside.

Preferably, the substrate in step (1) contains mogroside V, which can be from natural plant Lo Han Guo, or can be from semi-synthesis or total synthesis. Further preferably, the substrate has a luo han guo gan V content of 50% or more, preferably 70% or more, more preferably 90% or more.

Preferably, the auxiliary substrate in step (1) is at least one selected from the group consisting of lycopin, laminarin, and yeast glucan. The dosage of the auxiliary substrate is 10-20% of the weight of the mogroside V in the substrate. The purpose of adding the auxiliary substrate is to break the beta-1, 6 glycosidic bond under the action of beta-glucosidase, so that the auxiliary substrate is enzymolyzed into active beta-glucose residue.

Preferably, the buffer solution in step (1) is potassium dihydrogen phosphate-sodium hydroxide buffer solution, the concentration of the buffer solution is 0.01-0.05mol/L, the pH range of the buffer solution is 5.8-6.5, the dosage of the buffer solution is not particularly limited, and the substrate and the co-substrate can be sufficiently mixed. One of the purposes of selecting the potassium dihydrogen phosphate-sodium hydroxide buffer solution is to dissolve a substrate and an auxiliary substrate and provide the optimal enzymolysis pH value; the second purpose is K⁺Has activating effect on beta-glucosidase and glucosyltransferase.

Preferably, the concentration of the beta-glucosidase in the step (2) is 30-50u/mg, and the dosage is 0.5% -3% of the weight of the mogroside V in the substrate. One of the purposes of using beta-glucosidase is to decompose two glycosyl side chains of mogroside V molecule into a molecule of glucosyl (both are connected by beta-1, 6 glycosidic bonds) respectively, so that the mogroside V molecule is enzymolyzed into mogroside IIIE; the other purpose is to carry out enzymolysis on an auxiliary substrate (glucan or polysaccharide containing beta-1, 6 glycosidic bonds) into active beta-glucose residues, thereby providing important enzymatic reaction raw materials for the step (3).

Preferably, the temperature of the incubation reaction in step (2) is 55-65 ℃. If the reaction temperature is too low, the catalytic effect of the beta-glucosidase is reduced, and the catalytic reaction speed is slowed or the reaction is incomplete; if the reaction temperature is too high, the beta-glucosidase is denatured and inactivated, and the reaction is also not facilitated; the reaction time is kept for 8-15 h; the stirring speed of the heat preservation reaction is 60-100 rpm. If the stirring speed is too slow, the probability of contacting the beta-glucosidase with the substrate is reduced, so that the catalytic reaction speed is slowed or the reaction is incomplete; if the stirring speed is too high, the spatial structure of the enzyme is damaged by the excessively strong shearing force of the stirrer, so that the enzyme activity is reduced, and the catalytic reaction speed is also slowed or the reaction is incomplete.

Preferably, the temperature for heating and enzyme deactivation in the step (2) is 100-105 ℃, and the temperature of the reaction solution after enzyme deactivation is reduced to 5-10 ℃. The purpose of centrifugation is to precipitate and remove denatured and inactivated β -glucosidase and possibly excess co-substrate at low temperature.

Preferably, the glucosyltransferase in step (3) is present at a concentration of 3-10 u/. mu.L, in an amount of 1% -4% by weight of mogroside V in the substrate. The purpose of using glucosyltransferase is to synthesize mogroside IIIE and active β -glucose residues in filtrate A into mogroside in a buffer solution.

Preferably, the temperature of the incubation reaction in step (3) is 35-55 ℃. If the reaction temperature is too low, the catalytic effect of glucosyltransferase is reduced, and the catalytic reaction speed is reduced or the reaction is incomplete; if the reaction temperature is too high, the glucosyltransferase will be denatured and inactivated, which is also unfavorable for the reaction.

Preferably, the stirring speed in step (3) is 60-100 rpm. If the stirring speed is too slow, the probability of contacting glucosyltransferase with a substrate is reduced, so that the catalytic reaction speed is slowed or the reaction is incomplete; if the stirring speed is too high, the spatial structure of the enzyme is damaged by the excessively strong shearing force of the stirrer, so that the enzyme activity is reduced, and the catalytic reaction speed is also slowed or the reaction is incomplete.

Preferably, the reaction time in step (3) is 10 to 20 hours.

In the step (3), the purpose of centrifugation and filtration is to remove the inactivated and denatured enzyme and prevent the macroporous adsorption resin column from being blocked.

Preferably, the types of the macroporous absorption resin in the step (4) include, but are not limited to, D101, AB-8, LX-T28 and HP 20. The filtrate B containing mogroside obtained after centrifugation and filtration is passed through a macroporous adsorption resin chromatographic column, and the separation and purification purposes are achieved by utilizing the principle that macroporous resin only can adsorb mogroside (containing siamenoside) in the filtrate and cannot adsorb other components (excessive glucose residue, salt and the like) in the filtrate.

Preferably, in the step (4), the alcohol is at least one of methanol, ethanol and propanol.

The synthesis reaction formula of the method is as follows:

in the step (2), the beta-glucosidase simultaneously carries out enzymolysis on the mogroside V in the substrate and the beta-1, 6 glycosidic bond in the auxiliary substrate, and the reaction condition does not need to be finely controlled. In the prior art, when the mogroside V is subjected to enzymolysis, the reaction conditions need to be finely controlled, and a specific and selective enzyme or microbial strain is adopted in a matching manner, otherwise, excessive beta-D-glucose on a mogroside V glycosyl branch chain can be cut off, so that the content of the siamenoside in the product is reduced, and the yield of the siamenoside is reduced. Firstly, cutting off beta-D-glucose of two mogroside V in a substrate to obtain mogroside IIIE; the auxiliary substrate beta-1, 6 glycosidic bond is broken to generate active beta-glucose residue, and the mogroside IIIE and the active beta-glucose residue are synthesized into siamenoside with high efficiency in the presence of glucosyltransferase.

The method has the following beneficial effects:

(1) the method provides a brand-new way for obtaining the mogroside, namely enzyme-catalyzed semisynthesis, and can greatly improve the integral sweetness of the mogroside;

(2) the invention efficiently utilizes beta-glucosidase; in addition, one molecule active beta-glucose residue can be butted with a glycosyl side chain of the mogroside IIIE to generate a target product siamenoside, and the side reaction is less and the conversion rate is high. According to the process of the present invention, mogroside V is converted to mogroside in yields of over 90% and without the need for particularly elaborate control of reaction conditions and specific enzymes or strains of microorganisms, as is the case with conventional commercially available beta-glucosidases and glucosyltransferases.

(3) The method has the advantages of simple process, strong operability, low equipment requirement, mild reaction condition, low production cost, no use of flammable, explosive, toxic and harmful chemical solvents, safety, greenness, environmental protection and suitability for industrial production.

Detailed Description

The present invention will be further described with reference to the following examples.

The mogroside V or the grosvenor momordica extract used in the embodiment of the invention is purchased from Huacheng biological resource GmbH in Hunan; the macroporous adsorption resin used in the embodiment of the invention is purchased from New scientific and technological materials, Inc. of Xian lan and Xiao; the beta-glucosidase used in the embodiment of the invention is purchased from a source leaf organism, the model is S10047, and the specification is 40 u/mg; glucosyltransferase was purchased from Thermo Scientific, cat # EO0831, specification 5 u/. mu.L; the starting materials or chemicals used in the examples of the present invention are, unless otherwise specified, commercially available in a conventional manner.

In the embodiment of the invention, the content of mogroside V and mogroside is measured by adopting a High Performance Liquid Chromatography (HPLC) external standard method.

Example 1

(1) Preparation of a substrate solution: adding a substrate (10 g of pure mogroside V, the content of mogroside V is 98.16 percent and the content of siamenoside is not available through HPLC external standard method detection) and an auxiliary substrate (saxitin, 0.5g) into 80ml of potassium dihydrogen phosphate-sodium hydroxide buffer solution (the molar concentration is 0.05mol/L and the pH value is 6.0), heating to 50 ℃, and stirring until the mixture is completely dissolved to obtain a substrate solution;

(2) the synthesis method of the mogroside IIIE comprises the following steps: adding 0.15g of beta-glucosidase into the substrate solution, preserving heat at 60 ℃, stirring at the speed of 60rpm, and reacting for 9 hours until the reaction is complete to obtain a reaction solution I; heating the reaction solution I to 105 ℃, inactivating enzyme for 30 minutes, cooling to 5 ℃, centrifuging, and filtering to obtain a filtrate A containing mogroside IIIE and active beta-glucose residues;

(3) the synthesis method of the mogroside comprises the following steps: adding 0.4g of glucosyltransferase into the filtrate A, preserving the temperature at 40 ℃, stirring at the speed of 60rpm, and reacting for 10 hours until the reaction is complete to obtain a reaction solution II; heating the reaction liquid II to 105 ℃ to inactivate enzyme for 30 minutes, cooling to room temperature, centrifuging, and filtering to obtain filtrate B containing mogroside;

(4) and (3) post-treatment: and (3) passing the filtrate B through a macroporous adsorption resin chromatographic column (resin model: D101), washing with water, eluting with ethanol, concentrating the ethanol eluate, and vacuum drying to obtain 8.85g of finished mogroside.

The content of mogroside in the finished product obtained in this example was 89.43%, the content of mogroside V was 8.60%, and the conversion rate of mogroside V into mogroside was 92.25%, as determined by High Performance Liquid Chromatography (HPLC) external standard method.

Example 2

(1) Preparation of a substrate solution: adding substrate (fructus Siraitiae Grosvenorii extract, 10 g; mogroside V content 50.29%, siamenoside content 2.13% detected by HPLC external standard method) and auxiliary substrate (laminarin, 0.8g) into 50ml potassium dihydrogen phosphate-sodium hydroxide buffer solution (molar concentration 0.05mol/L, pH 6.5), heating to 50 deg.C, and stirring to dissolve completely to obtain substrate solution;

(2) the synthesis method of the mogroside IIIE comprises the following steps: adding 0.2g of beta-glucosidase into the substrate solution, keeping the temperature at 57 ℃, stirring at the speed of 90rpm, and reacting for 10 hours until the reaction is complete to obtain a reaction solution I; heating the reaction solution I to 100 ℃, inactivating enzyme for 30 minutes, cooling to 5 ℃, centrifuging, and filtering to obtain a filtrate A containing mogroside IIIE and active beta-glucose residues;

(3) the synthesis method of the mogroside comprises the following steps: adding 0.15g of glucosyltransferase into the filtrate A, preserving the temperature at 45 ℃, stirring at the speed of 90rpm, and reacting for 12 hours until the reaction is complete to obtain a reaction solution II; heating the reaction liquid II to 100 ℃ to inactivate enzyme for 30 minutes, cooling to room temperature, centrifuging, and filtering to obtain filtrate B containing mogroside;

(4) and (3) post-treatment: and (3) passing the filtrate B through a macroporous adsorption resin chromatographic column (the resin model is LX-T28), washing with water after the column is completed, eluting with methanol, concentrating the methanol eluent, and drying in vacuum to obtain 9.42g of finished mogroside.

The content of mogroside in the finished product obtained in this example was 44.34%, the content of mogroside V was 5.24%, and the conversion rate of mogroside V into mogroside was 90.19%, as determined by High Performance Liquid Chromatography (HPLC) external standard method.

Example 3

(1) Preparation of a substrate solution: adding substrate (fructus Siraitiae Grosvenorii extract, 10 g; mogroside V content 65.07%, siamenoside content 0.24% detected by HPLC external standard method) and auxiliary substrate (yeast dextran, 1g) into 60ml potassium dihydrogen phosphate-sodium hydroxide buffer solution (molar concentration 0.05mol/L, pH 5.9), heating to 50 deg.C, and stirring to dissolve completely to obtain substrate solution;

(2) the synthesis method of the mogroside IIIE comprises the following steps: adding 0.3g of beta-glucosidase into the substrate solution, preserving heat at 65 ℃, stirring at the speed of 100rpm, and reacting for 12 hours until the reaction is complete to obtain a reaction solution I; heating the reaction solution I to 105 ℃, inactivating enzyme for 30 minutes, cooling to 5 ℃, centrifuging, and filtering to obtain a filtrate A containing mogroside IIIE and active beta-glucose residues;

(3) the synthesis method of the mogroside comprises the following steps: adding 0.2g of glucosyltransferase into the filtrate A, preserving the temperature at 37 ℃, stirring at the speed of 100rpm, and reacting for 15 hours until the reaction is complete to obtain a reaction solution II; heating the reaction liquid II to 100 ℃ to inactivate enzyme for 30 minutes, cooling to room temperature, centrifuging, and filtering to obtain filtrate B containing mogroside;

(4) and (3) post-treatment: and (3) passing the filtrate B through a macroporous adsorption resin chromatographic column (resin type: AB-8), washing with water, eluting with ethanol, concentrating the ethanol eluate, and vacuum drying to obtain 9.24g of finished mogroside.

The content of mogroside in the finished product obtained in this example was 56.66%, the content of mogroside V was 5.89%, and the conversion rate of mogroside V into mogroside was 91.63%, as determined by High Performance Liquid Chromatography (HPLC) external standard method.