JPS5951560B2 - Steviosydno Seizouhouhou - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for producing stevioside, and an object of the present invention is to provide a new method for producing stevioside by adding water to the leaves and stems of stevia to purify the liquid that extracts stevioside. do.

Stevioside is a compound that is attracting attention as a sweetener, and is a plant that grows naturally in Balaguay;
arebaudiana 3 Bertoni), mainly in the leaves and stems.

The molecular formula is C38H60018, and the structural formula is as follows, published in the Journal of American
Chemical Chemistry (J, AmericanChe)
(micalSociety) Volume 78 Page 4709-4
710, reported in 1956.

This stevioside crystal is colorless and odorless with a melting point of 196.
~198°C, extremely hygroscopic. .

■9 Metabolism L゛□ CHρHo Stevioside Structural formula Stevioside is said to have a sweet taste and is about 300 times sweeter than sugar.
Its sweet taste is very similar to the taste curve of sugar.

It is non-toxic and excreted within a short time, making it a promising sweetener for low-calorie or non-calorie foods. Stevia is originally from Paraguay in South America, but trial cultivation has recently been carried out in Japan, and it appears that it can be grown in other parts of Japan as well.

The stevioside content in Stevia varies depending on the cultivation conditions and variety, and is 1.2 to 7.3% (Mitsuhashi et al., Pharmaceutical Journal, Vol. 95, 1).
27-1301975).

The following method is known as a method for extracting and purifying stevioside from stevia leaves. (1) Add water to the dried ground stevia leaves, extract, treat with cation exchange resin and anion exchange resin, desalt and decolorize, concentrate, dissolve in hot dioxane, cool and crystallize. Method. and (2) a method in which chloroform is added to a dried ground product of Stevia leaves to defatte the product, followed by extraction with hot dioxane, which is then concentrated to form a syrup and crystallized. (3) Similar to (2), air-dried leaves defatted with chloroform are extracted with water, freeze-dried, and then extracted with hot dioxane. A method of crystallization after concentration. etc. Method (1) is described by Utsudo et al.
Journal of Organic Chemistry Volume 20, pages 875-883, 1955 OΠRRYB, WO
ODetal, T. Organic Chemistry
vOl. 2O, 875-883, 1955).

(2) and (3) are described in US Patent Publication No. 3,723,410, published March 27, 1973, by GEORGIAJ.

In addition, historical documents prior to the determination of the structural formula include Derrytrich (
K. DIETERICH19O9, Pasenatsk (P.
PASENACK198O), Bridel et al. (M.BR
IDELANDR. LAVIE-ILLE1931)
There is a report by et al., which states that stevioside was extracted with methanol or ethanol. still. An abstract of the above content is available in Chemical Abstracts, Volume 50, Volume 195.
6, 5581e, also volume 51, 1957, 7660f
-2661a and Vol. 103868Z, 1973.

In the quantitative method of stevioside, after extraction by method (1), it is converted to steviol and quantitatively determined by gas chromatography, so the extraction process is based on method (1). still. Further, JP-A-50-46871 discloses a method for obtaining a liquid containing a sweet component by adding one or more selected from glycerin, sorbitol, and propylene glycol to stevia leaves.

However, this method is not intended to purify and obtain stevioside itself. These extraction methods can be roughly divided into two methods: an extraction method using water and a method in which defatting with chloroform is followed by extraction using water or dioxane. The inventors of the present invention conducted additional studies on the above-mentioned known methods, and found that in method (1), it is difficult to pass through the mouth to obtain an extract from the soaked liquid of leaves and stems.

The extract has a deep brown color, almost black, and contains large amounts of components other than stevioside, such as inorganic salts, amino acids, carbohydrates, soluble proteins, nucleic acids, and pigments, so it is necessary to remove a large amount of impurities. Although stevioside is well extracted with water, the soaking solution exhibits thixotropic properties, so the extract cannot be separated unless a large amount of water is used. For purification, crystallization will not occur unless the extract is treated with a cation and anion exchange resin to desalt and decolorize it. Naturally, the amount of the extract will be large to dilute it, and a large amount of ion exchange resin and its regenerated solution will be required. It takes a long time and costs a lot of money to concentrate it. Purification by ion-exchange resin treatment is insufficient, and crystallization does not occur unless it is dissolved in hot dioxane. I learned that there are many drawbacks such as: Methods (2) and (3) first degrease with an organic solvent, so they are somewhat effective in reducing mouthfeel and decolorization, but they are then extracted with hot dioxane or water, which requires a large amount of dioxane, and A large amount of impurities are extracted at the same time.

In the above literature, it is easy to see that water is used for extraction and the crystals are hygroscopic, so it is easy to see that they are easily soluble in water. However, it is very easy to elute.

The present inventors have recognized that water provides the highest extraction amount among various extraction solvents, and the conventional method has problems such as difficulty in filtration and complicated desalination and decolorization operations using ion exchange resins.

As a result of various studies to solve the problems such as the need to concentrate a large amount of extract liquid, we found that if a method using a cationic surfactant or a cationic polymer flocculant is adopted, a large amount of contaminants, which is a disadvantage of the water extraction method, can be avoided. The present invention was completed based on the knowledge that a stevioside extract can be obtained by precipitating and purifying impurities. That is, in the method of the present invention, water is added to the dried ground product of Stevia leaves and stems to obtain a stevioside exudate or extract, and then a cationic polymer flocculant or a cationic surfactant is added to the insoluble substance pigment. This is a method for producing stevioside, which is characterized in that impurities such as polysaccharides and proteins are coagulated and precipitated, and after the aggregates are removed, stevioside is obtained from the residual liquid by a conventional method.

Next, the configuration and effects of the method of the present invention will be explained.

First, the drawbacks of the conventional method will be described in more detail as follows. The known method for water extraction of dried ground Stevia leaves and stems uses 6 to 30 tons of water per 1Kf of the ground material, and as a result of follow-up tests, it is easy to extract with water, but when the amount of water is small, natural filtration is not enough. It was found that no oral fluid was obtained.

This is because there is a large amount of suspended matter in the mouth, and the gaps in the mouthpiece, such as paper, cloth, etc., quickly close up, and even if the extract is allowed to stand still, the suspended matter does not settle. One reason is that it contains fat. Although it is possible to obtain a small amount of oral fluid or supernatant through suction port filtration and centrifugation, with suction port filtration, as with natural mouth filtration, the pores of the mouth filtration material quickly become clogged and the material must be replaced frequently. Must be. Also, in the centrifugation method, since the specific gravity of the precipitate is low, the amount of supernatant obtained is small, and since the precipitate contains a large amount of water, stevioside remains in the residue. Furthermore, the oral fluid is a greenish-brown color that is almost black. For these reasons, it is unavoidable to wash the extraction residue with a large amount of water, which increases the amount of extracted liquid, which is disadvantageous for evaporation to dryness. Furthermore, when an ion exchange resin is used for decapsulation and desalination, a large amount of resin and regenerating liquid are required, and disadvantages arise one after another, such as wastewater treatment caused by desorption of the ion exchange resin. In the method of the present invention, water is used because stevioside in Stevia leaves and stems is most easily extracted by water, but at the same time, a cationic polymer flocculant or a cationic polymer flocculant is used to remove a large amount of extracted impurities. Using a surfactant, many other components are coagulated and precipitated and removed while stevioside remains dissolved, resulting in an extract with a slightly yellow color.

The present inventors have studied various methods for agglomerating impurities. That is, (1) PH adjustment, (2) Cal. Addition of lithium ions, (3) Utilization of aluminum sulfate, (4
) coprecipitation with ferric hydroxide, (5) heating, (6) anionic polymer flocculant, (7) nonionic polymer flocculant, (
We attempted to use 8) a cationic polymer flocculant, (9) a cationic surfactant, etc. In the experiment, the dried and ground Stevia leaves and stems 109 were immersed in water 60a, centrifuged, and the supernatant was used as an extract to perform various aggregation treatments. It was confirmed by thin layer chromatography that stevioside did not precipitate together with the aggregates but was dissolved. For thin layer chromatography, 250 μm of silica gel and 0.0 μm of thin layer aluminum sheet were used.
After immersing in 02M sodium acetate solution, drying and buffering, the solution after the various aggregation treatments mentioned above was prepared in 1.
5 μt spread, developing solvent was 65% ethyl acetate.
Developed with isopropanol (65:35) for 4 hours. The coloring agent was a 2% Anthrone concentrated sulfuric acid solution, which was confirmed by spraying and heating to develop a blue color. The results of various agglomeration methods are summarized and shown in the table below.

That is, by adding a cationic polymer flocculant or a cationic surfactant, a decolorized supernatant can be obtained.

Anionic polymer flocculants such as sodium alginate, carboxymethyl cellulose, and sodium polyacrylate are not effective, and nonionic and amphoteric polymer flocculants are effective against flocculation of starch, gelatin, polyacrylamide, etc. No decolorizing effect was observed. From these results, it is thought that most of the impurities are negatively charged components.
The product name for the cationic polymer flocculant is Prestol 185.
K) and 222K (manufactured by Bayer AG, Germany, component: polyaminocarboxylic acid ester, molecular weight: approximately 100,000 or less), and alkyldimethylbenzyl ammonium chloride (manufactured by Tokyo Kasei Co., Ltd.) was used as the cationic surfactant. . The required amount to exhibit the agglomeration effect was determined as follows. That is, 10 g of dried ground Stevia leaves and stems should be mixed with 1 portion of water.
20" was added and immersed, the mixture was centrifuged and the supernatant was collected as an extract. This extract was dark brown and almost black, so it was impossible to observe the formation of aggregates, so it was further diluted 2 times. 0.005, 0.0 of a cationic polymer flocculant or a cationic surfactant was used for 5 grams of this liquid.
The aggregation and decolorization effects were compared when 5%, 0.5%, and 5% aqueous solutions of 1.0% were added. The amount added is 0.02, 0.2, 2.4 and 24% to the dried ground Stevia leaves and stems.
corresponds to The effect is shown at 2.4% or more of the dried ground product of Stevia leaves and stems, and no effect at all at 0.2% or less. The amount showing this addition effect is just an example, and does not limit the present invention, as it varies depending on the method of preparing the dried Stevia leaves and stems, the variety of Stevia, the soaking time during extraction, the amount of liquid, etc. . Further, in the above method, the centrifuged supernatant was used to evaluate the effect, but the supernatant may be directly added to the immersion liquid. In this case, the viscosity of the soaking liquid decreases, and a yellow extraction liquid can be obtained even by natural filtration, so the stevioside extract can be easily purified with excellent dehydration, filterability, and decolorization. Next, embodiments of the method of the present invention will be described.

First, the amount of water used for extraction is 6 tons or more per 1 Kf of dried ground Stevia leaves and stems. If it is less than this, it is difficult to stir, which is inconvenient. Stevioside is eluted in a shorter time if heated during extraction, but heating is not necessarily required. Calcium carbonate may be added to prevent the pH of the soaking liquid from becoming acidic, but this has little effect on the yield.

Next, to remove insoluble components by filtration, it is better to use centrifugation or a filter press, as natural filtration takes time. If you omit this filtration operation and directly add a cationic polymer flocculant or cationic surfactant to the soaking liquid for flocculation treatment, the sediment volume will be smaller and filtration will be easier, so the number of times the sediment will be washed will be reduced. It is also possible to reduce The method for adding a cationic polymer flocculant or cationic surfactant is to dilute them with water, add them little by little, and stop when coagulation and decolorization are completed. The amount added varies depending on the amount of Stevia raw material extract and the type of flocculant, but it may be added in an amount of 2.0 to 5.0% or less based on the dried ground product of Stevia leaves and stems. After coagulation and filtration, a furnace solution is obtained, and the precipitate is washed with water, combined with the solution, concentrated to dryness, and then purified by dissolving it in methanol to precipitate crude crystals using a conventional method. According to the method of the present invention as described above, stevioside can be easily extracted from the leaves and stems of stevia in an extremely high yield.

Next, examples of the method of the present invention will be given.

Example 1 109 parts of dried ground Stevia leaves and stems from Paraguay in South America and 6 parts of water
Add 0WLe and soak in a cationic polymer flocculant (product name: Prestol 185K2.0, manufactured by Bayer AG, Germany).
% solution was added and mixed, and after 2 hours, the mixture was filtered using filter paper to obtain a pale yellow filtrate.

Water was added to wash the residue on the filter paper, and the washing liquid was combined with the Sakinoto liquid. After concentrating this to dryness, dissolve it in methanol,
Insoluble matter was filtered and cooled on ice overnight to obtain crude crystals of stevioside. Repeat the re-crystallization process to further form an ellipse with a melting point of 185 crystals to 18 crystals.
0.329 crystals of stevioside were obtained. Example 2 109 parts of the dried ground Stevia leaves and stems as in Example 1 and 1 part of water
Add 20 ml of water, soak, centrifuge, remove the supernatant, and collect the precipitate twice at 60 ml. Washed with Ne water.

Collect the supernatant and washing liquid, and add cationic surfactant alkyldimethylbenzyl ammonium chloride to this.
．． After adding 1 g of 0% aqueous solution and mixing, the mixture was allowed to stand for 30 minutes and then filtered. The precipitate was washed and the washing liquid was combined with the previous filtrate to obtain a pale yellow extract with a total volume of 260 g. Example 1 from this
The mixture was concentrated to dryness in the same manner as above to form a syrup, and further ovalized using methanol in a conventional manner to obtain crude crystals 432~. Reference Example The crystals obtained in Examples 1 and 2 were dissolved in water to make a 0.1% solution, and 1" was added to 1 ton of pure brewed soy sauce to produce soy sauce with enhanced sweetness.

Claims (1)

[Claims] 1 Add water to the dried ground product of Stevia leaves and stems to obtain a stevioside exudate or extract, and then add a cationic polymer flocculant or a cationic surfactant to this to remove insoluble substances, pigment polysaccharides, and protein impurities. A method for producing stevioside, which comprises coagulating and precipitating stevioside, removing the aggregates, and then obtaining stevioside from the residual liquid.