JPS58212760A - Purification of stevia sweetening substance - Google Patents

Abstract

PURPOSE:To purify a stevia sweetening substance in high efficiency, by extracting Stevia rebaudiana Bartoni with water, adjusting the prepared extracted solution to a proper pH, adding calcium hydroxide to the solution so that impurities are precipitated, adding a water-soluble organic solvent to the prepared filtrate so that impurities are precipitated. CONSTITUTION:Stevia rebaudiana Bartoni is extracted with water or an alcohol, a pH adjustor such as hydrochloric acid, etc. is added to the prepared extracted solution, which is adjusted to <=4pH. Calcium hydroxide is added to the solution so that impurities in the extracted solution are precipitated and filtered off. A water- soluble organic solvent such as methanol, etc. is added to the prepared filtrate, and impurities in the filtrate precipitated and removed. The amount of the water-soluble organic solvent is 5-50wt% based on the filtrate after its addition. When a stevia sweetening substance is purified by an ion exchange resin or adsorption resin, load on the resin is reduced and drop of function is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for extracting and purifying natural sweet substances contained in Stevia lepacdeiana Bertoni, a member of the Asteraceae family.

Stevia lepakudeiana Bertoni (hereinafter referred to as stevia) leaves and stems, mainly leaves, in addition to stevioside, lipacudi A side A1-1 bacudi bud side C, lipacudiopoid D1 lipacudiopoid E and zurcoduide A'1! It contains a sweetener (hereinafter referred to as stevia sweet substance) having a chemical structure similar to Stevioside F.

To extract and purify stevia sweet substances from stevia, stevia leaves are extracted with water or hydroalcohol, and the resulting extract is treated with an ion exchange resin to remove impurities, or the extract is made non-polar. Generally, Stevia sweet substances in the extract were selectively adsorbed by treatment with an adsorbent made of a synthetic resin, and then desorbed.

However, the above extract contains a large amount of impurities such as bitter substances, colored substances, and odorous substances.
When carrying out the above treatment, a large load is placed on the ion exchange resin and the adsorption resin, causing a decrease in the functionality and deterioration of these resins.

Therefore, in order to reduce the load on the above-mentioned tree W#, various methods have been proposed to remove impurities from the extract in advance. For example, methods of adding lucium hydroxide, lucium chloride, etc. to the extract are known. There is. However, even with the above method, the removal of impurities in the extract was not sufficient, and clogging and contamination of the ion exchange resin and adsorption resin were not sufficiently eliminated.

The present invention is based on the above-mentioned current state of the purification method of stevia sweet substance.
The purpose of this method is to provide a purification method that can precipitate and remove impurities in Stevia extract with higher efficiency than conventional methods.
Bertoni is extracted with water or alcohol, and a pH adjuster is added to the strained extract to bring the pH of the extract to 4 or less, and then lucium hydroxide is added to precipitate impurities in the extract. The present invention provides a method for purifying a stevia sweet substance, which is characterized by adding a water-soluble organic solvent to the obtained liquid F to precipitate and remove impurities in the liquid F.

The present invention will be explained in more detail below.

Stevia extraction process with water or alcohol, usually
Preferably 2 to 15 Kf of Stevia leaves ib ・Preferably #'i3
-10KF of water or hydrous alcohol Kfi is crushed in most cases by heating, but it may also be immersed in warm water from the beginning. The stevia to be subjected to the extraction process may be a mixture of leaves and a portion of the stem, or may be the whole stevia plant crushed appropriately using a dodge crusher, a cone crusher, or the like. The higher the extraction temperature, the sweeter the stevia will be.
□ Although the extraction efficiency of substances is high, the extraction amount of impurities also increases, so the temperature is usually set at 50 to 80°C.

The pH of the above-mentioned extract obtained by extracting sweet substances from Stevia leaves or stems is usually about 5 to 7, but in the present invention, a pH adjuster is added to this extract or concentrate. In addition, p)l is set to 4 or less, and then a hydroxide is added.

Suitable examples of pH adjusters include hydrochloric acid and phosphoric acid, and in some cases it is also possible to use metal chlorides, but the pH of the extract can be lowered to 4 or less by using a small amount. Hydrochloric acid is most preferred because it is easy to use and easy to use. The pH of the extract just before adding calcium hydroxide is preferably 1-&5, since even if it is excessively low, impurities will not be dissolved if they are precipitated in particularly large quantities.

The amount of lucium hydroxide added depends on the concentration of the extract, but if it is too small, impurities may precipitate and the amount of coagulation method WI will be small. % or more, and if the pH of the extract is too high, there is a risk that the extracted Stevia sweet substance will decompose, so the pn of the extract is usually 13F!, I'
The amount should be such that it does not exceed 12 degrees.

The precipitates produced by the addition of lucium hydroxide are generally large flocs and are easily separated and removed by filtration. A piece of paper is generally used as a filter pattern, and F
In order to increase the A rate, pressurization and vacuum filtration are performed as appropriate.

A water-soluble organic solvent is added to the F solution obtained by separating the precipitated impurities from house to house to further precipitate the impurities in the P solution.

Specific examples of water-soluble organic solvents include methanol, ethanol, glopanol, and meacetone. Methanol, ethanol, and propatool are preferably used, and methanol is particularly preferably used. If too much, there is a risk that some of the stevia sweetening substance will be lost when the lead precipitated impurities are removed from door to door.
), if the amount is too small, the effect of settling the dull material due to the addition of the solvent will not be achieved, so it is preferably 5 to 5
The amount is set to 0% by weight, more preferably 10 to 30% by weight.

In addition to the stevia sweetening substance, the F solution often contains impurities mainly consisting of various salts with smaller molecular weights, so the VCP solution is treated with an ion exchange resin to remove the remaining impurities. Or I11 with synthetic resin adsorbent! Alternatively, the Stevia sweet substance in the F liquid may be selectively adsorbed and then desorbed by the stevia sweet substance in the F liquid.

The method for purifying the stevia sweet substance of the present invention is configured as described above, and according to the present invention, compared to the conventional method of adding lucium hydroxide, lucium chloride, etc. to the stevia extract, the Impurities are removed at an extremely high rate by precipitation, resulting in a purified stevia sweet substance with a low degree of coloration.

Furthermore, when the Stevia sweet substance is subsequently purified using an ion exchange resin or an adsorption resin, the load on these resins can be reduced and the deterioration in function can be minimized.

Examples of the present invention and comparative examples are shown below.

% simply indicates weight %.

Separation of the shichimi substance t#i was also carried out by liquid chromatography under the following conditions.

Equipment Futsuki Oters Co. 1 660 type power ram 2 μ bong pack / NH.

Eluent Niacetonitrile/Water (volume ratio 80/20) Detection^: UV-210 Engineering Example-1 After that, it was left to stand for 2 hours, and the stevia leaves were removed by centrifugation to obtain a 7-day extract. The color of the extract is dark black, and the concentration of solids, sweet ingredients, and impurities are 955% and 955% respectively.
%, 152596.443096.

When 2002 was separated from the above extract and adjusted to pH 3 by adding hydrochloric acid, a small amount of precipitate was deposited. Further, 200 y of lucium hydroxide was added to this solution to produce a large amount of precipitate, and the precipitate was removed by filtration. The weight of the precipitate was H5,559.

Methanol 60F was added to the obtained p-liquid to produce a summer precipitate, and the precipitate was removed by filtration. The total amount of sunken material η (nk Fi7.
It was 09 f. Also, the shichimi component in the final P solution is 3.02
1 (yield 99%).

Therefore, the impurities removed from the extract by the above pH adjustment and the addition of lucium hydroxide and methanol were 5.09
The removal rate of impurities was calculated to be about 57% or more.

The color of the finally obtained liquid F was pale yellow.

Example-2 200y was taken from the extract obtained in Example-1, and hydrochloric acid was added to adjust the pH to 2, and lucium hydroxide zoo
y was added to form a precipitate, which was then separated. Obtained F
Add methanol 202 to the liquid to further produce sediment,
Removed. The total amount of precipitate was #i6.31F.

In the same manner as in Example 1, the impurity concentration was 4.31f or more,
It was calculated that the impurity removal rate Fi was 48% or more.

The color of the obtained liquid F was pale yellow.

Comparative Example-1 When 2002 was separated from the extract obtained in Example-1 and the pH was adjusted to 2 by adding hydrochloric acid, a small amount of precipitate was deposited (G, 48r). It was calculated that all of the precipitates were impurities and the impurity removal rate was 5.4% from the amount of sweet components in the F solution after P separation. The color of the obtained liquid V was brownish brown.

Comparative Example-2 2002 of the extract obtained in Example-1 was separated and 200y of lucium hydroxide was extracted without adjusting the pH of this liquid.
was added to form a precipitate (4,44f). Example 1
In the same way as above, the impurities are 2. ．． 44 f or more, the impurity removal rate was calculated to be 27°5% or more. The color of the obtained liquid F was brown.

Comparative Example-3 200y was taken from the extract obtained in Example-1, and lucium chloride zooy was added to this liquid to form a precipitate (2,85y).
p). In the same manner as in Example 1, remove impurities (
It was calculated that L85jF or higher and the removal rate was 9.6% or higher. The color of the F solution was a black border color.

Comparative Example-4 In Comparative Example-2, instead of adding 2y of calcium hydroxide, 2y of lucium chloride was added, and then 30% of methanol was added.
The precipitate produced when treated with F was 3.28 f.
Met. In the same manner as in Example 1, it was calculated that the impurities were 128F or higher and the impurity removal rate was 14.4% or higher. The color of the obtained solution F was dark green.

patent applicant Sekisui Chemical Co., Ltd. Representative: Mototoshi Fujinuma 316-

Claims (1)

[Claims] L Stevia lepacdeiana Bertoni is extracted with water or alcohol, and a K pH adjuster is added to the resulting extract to adjust the pH to 4 or less, followed by monohydroxidation. A stevia sweet flavor characterized by adding a water-soluble organic solvent to the obtained F solution to precipitate and remove the impurities in the P solution. Methods for purifying substances. 2. The purification method according to item 1, which is pH-adjusted gold hydrochloric acid or phosphoric acid. 3. pH adjustment pH of the extract after adjustment by adding gold
The purification method according to item 1 or 2, wherein H is 10 to 3.5. Table 1. The purification method according to Items 1 to 3, wherein the water-soluble organic solvent is at least one of methanol, ethanol, and pro/hydrol. 5. The purification method according to items 1 to 4, wherein the amount of the water-soluble organic solvent added is 5 to 50% by weight based on the added p-liquid.