JPS585018B2 - Extraction method of sweet substances - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for extracting sweet substances from the underground parts of plants belonging to the genus Periandra or sweet substance-containing products prepared therefrom.

Plants of the genus Perianthra are shrubs of the Fabaceae family that grow naturally in northern and central Brazil.
lcácus de terra (in English: nativ
It has been used for medicinal purposes such as phlegm since ancient times.

The roots of the wood shaving plant contain a sweet taste, but they also have a fairly strong bitter taste.

Therefore, an extract of a sweet substance such as water or a water-hydrophilic organic solvent is usually contaminated with this bitter substance, as well as coloring substances, proteins, polysaccharides, etc. cannot be used as

Various purification means are required to separate these contaminants and sweet substances.

The present inventor has conducted extensive research on a method for extracting sweet substances from the underground parts of plants of the genus Perianthra or sweet substance-containing products prepared therefrom, while minimizing the accompaniment of other contaminants. A highly pure sweet substance extract can be obtained by performing an extraction treatment with a hydrophilic organic solvent containing water under acidic conditions with a pH of less than 3, and the pH of the extract can be adjusted to 3 or more, preferably p
The present invention was completed based on the finding that a sweet substance can be obtained as a precipitate with almost no bitterness by neutralizing to H5 or higher.

In the present invention, a representative example of a plant of the genus Perianthra from which sweet substances are extracted is Perianthra mediterranea.
), Perianthra dulcis
ulcis), etc.

Since sweet substances are present in the underground parts and roots of these plants, the underground parts or their dried products are shredded or crushed as necessary and subjected to the extraction operation.

In addition, sweet substance-containing substances prepared from the underground parts of plants belonging to the genus Perianthra refer to concentrates of sweet substance extracts or extracts thereof using water or water-hydrophilic organic solvents (hydrophilic organic solvent concentration is 80% or less). It means a concentrate of a solution containing a sweet substance or a precipitate containing a crude taste substance obtained by partially refining the substance.

Although the partial purification treatment of the extract is not particularly limited, a purification method particularly effective for sweet substances of plants belonging to the genus Perianthra will be exemplified below.

It has been found that sweet substances from plants of the genus Perianthra precipitate from an aqueous solution under acidic conditions at a pH of less than 3, but most of the bitter substances remain in the solution.

When this acidic precipitation treatment is applied to an aqueous solution prepared directly from the extract, various acid-insoluble substances such as proteins are also co-precipitated in addition to sweet substances.

In order to reduce co-precipitation of proteins, etc., there are methods to decompose acid-insoluble substances such as proteins into acid-soluble peptides and amino acids by treatment with enzymes such as protease before acid precipitation treatment, or to reduce co-precipitation at 70°C or higher. A method in which proteins are aggregated and removed by heating, or by adding calcium hydroxide, magnesium hydroxide, or aluminum hydroxide, or by adding these metal salts, and then adjusting the pH to alkaline to add metal hydroxides to the solution. A method of precipitating and removing proteins by generating them can be adopted as necessary.

As the acidic precipitating agent, mineral acids such as hydrochloric acid and sulfuric acid are usually economically used.

During acidic precipitation, the precipitation yield can be improved by adding neutral salts such as sodium chloride, sodium sulfate, sodium nitrate, sodium formate, and sodium acetate to the salting-out effect.

The acidic precipitated sweet substance content is decanted,
It is separated by centrifugation or filtration, and can be directly subjected to the extraction process of the present invention.

Under slightly acidic to alkaline pH conditions of pH 3 or higher, preferably pH 5 or higher, the solubility of sweet substances in hydrophilic organic solvents of approximately 85% or higher is low, but since bitter substances are soluble, it is possible to separate the two. .

Therefore, after concentrating or concentrating to dryness the aqueous extract or the solution obtained by partially purifying the process, about 85% or more
By adding a hydrophilic organic solvent to a concentration of preferably 95% or more, a sweet substance-containing precipitate separated from hydrophilic organic solvent-soluble substances such as bitter substances can be obtained.

Other methods include weakly basic anion exchange resin, D
Sweet substances and other contaminants are removed by fractional adsorption or fractional elution using adsorbents such as ion exchangers such as EAE cross-linked dextran, synthetic adsorption resins, silica gel, granular polyamide, activated carbon, activated alumina, activated clay, and diatomaceous earth as carriers. Methods such as separation, molecular sieve membrane, dialysis membrane treatment, etc. are applied.

Specific examples of the hydrophilic organic solvent to be applied in the present invention include lower alcohols such as methanol, ethanol, propatool and butanol, lower ketones such as acetone and methyl ethyl ketone, and dioxane. Examples include ethanol, followed by acetone and propatool.

The amount of water present during extraction varies depending on the type of hydrophilic organic solvent, but in the case of ethanol it is about 15% or less, preferably about 5% or less, and depends on the water content of the object to be extracted and the amount of hydrophilic organic solvent. It is necessary to adjust the water content respectively.

The extraction pH is less than 3, and when it becomes 3 or more, the solubility of the sweet substance decreases, making extraction difficult.

Preferably the pH is 1 to 2.5.

As the pH adjuster, mineral acids such as hydrochloric acid and sulfuric acid may be used.

The extraction temperature may be in the range above the freezing point and below the boiling point of the extractant; low-temperature extraction involves less contaminants, and high-temperature extraction shortens the extraction time.

Preferably it is 5 to 70°C. The extraction time varies depending on the type of extractant, the type of extraction target, the extraction temperature, and the extraction pH, and may be appropriately determined depending on each case.

By such an extraction process, sweet substances can be extracted with less accompanying impurities such as bitter substances and colored substances.

As mentioned above, sweet substances are insoluble in water-containing hydrophilic organic solvents with a pH of 3 or higher, so after separating the extract and the extraction residue, by adjusting the pH of this extract to 3 or higher with an alkali, Furthermore, a sweet substance-containing substance with less bitterness can be obtained as a precipitate, and this two-step combination is extremely effective.

Precipitation of this sweet substance is accelerated under low temperature conditions, so p
It is preferable to adopt a method of cooling and leaving after H adjustment.

The precipitate containing the sweet substance is separated from the hydrophilic organic solvent solution by methods such as centrifugation, filtration, and concentration.

As a method other than neutralization of this water-containing organic solvent extract, the extract is separated from the extraction residue, concentrated to remove the hydrophilic organic solvent, suspended in water, and then neutralized with alkali. There is a method to obtain it as an aqueous solution.

The sweet substance extract obtained in this way is further treated with ion exchange resin, adsorbent treatment, molecular sieve membrane,
A more purified form is obtained by appropriately selecting and combining dialysis membrane treatment, decolorization treatment with a bleaching agent such as hydrogen peroxide, etc.

Although the sweet substance in plants of the genus Perianthra has not been identified, it is clearly distinguished from glycyrrhizin in licorice because it has no ultraviolet absorption, and its behavior on thin layer chromatography is different from that of other natural sweet substances such as stevioside. It appears to be a new substance.

Sensory testing of the crude product revealed that it has a sweetening power equal to or higher than that of stevioside, and exhibits a gentle and elegant sweetness.

Hereinafter, the method of the present invention will be specifically explained with reference to Examples.

However, these are merely examples of embodiments and do not limit the present invention in any way.

Example 1 Periandra dulcis
cis) root into 9 to 30 meshes with a hammer mill, add 500 ml of 0.1N hydrochloric acid and 9.51 ethanol of ethanol to 1 kg, extract overnight at room temperature at pH 2, and separate the extract and extraction residue by filtration. and the extraction residue was diluted with acidic ethanol 2
Combine the washing solution washed in step 1 with the extract solution, neutralize this with sodium hydroxide to pH 7.0, separate the resulting precipitate and dissolve it in water to a concentration of about 21, and adjust the pH to 5.0. , adsorption resin, H8 resin (Hokuetsu Tanso Kogyo Co., Ltd.) 100 ml column was passed through a 100 ml column at 5 V = 5 for decolorization and purification, and the passed liquid and water washing liquid were combined and concentrated to obtain 100 ml of a sweet extract without bitterness. .

Example 2 Perianthra dulcis (P
eriandra dulcis) root dry powder 100
700ml of water was added to g and extracted at 70°C for 5 hours, the extract and extraction residue were separated by filtration, 300ml of water was added to the extraction residue, secondary extraction was performed at 70°C for 2 hours, and the primary and secondary extracts were separated. In total, a sweet substance extract (pH 4, 5) 11 was obtained.

This was applied to a 200 ml column of polystyrene-based porous adsorption resin cross-linked with divinylbenzene, Diaion HP40 (manufactured by Mitsubishi Chemical Corporation) (hydrochloric acid regeneration) at 5 V = 2.
After washing the column with 500ml of water,
% ammonia water, and the sweet substance-containing fractions were collected and concentrated to obtain 10 ml of concentrate.

Hydrochloric acid was added to this sweet substance-containing concentrate to adjust the pH to 2, and the mixture was centrifuged at 3000 r, p, m,/min to form a precipitate of approximately 1
Increased g.

Add 50 ml of 95% ethanol to extract and ferment the sweet substances. After removing the unfermented substances by centrifugation, the extract was adjusted to pH 6.5 with sodium hydroxide to eliminate the precipitation of sweet substances. .8g was obtained.

This stuff had no bitterness at all.

Example 3 Perianthra dulcis (P
eriandra dulcis) root dry powder 500
Add 21 parts of water to g, extract at 70℃ for 5 hours, and add 1 part of water to
．． Repeat the extraction twice with 51 g of each sample, filter and combine the extract with the extraction residue, concentrate to a liquid volume of 500 g, adjust the pH to 1.8 with hydrochloric acid, and leave at 5°C overnight to obtain a sweet substance-containing precipitate. The material was filtered.

The procedure of extracting this precipitate with 100 ml of acidic 93% ethanol at room temperature was repeated three times, the extracts were combined, the pH was adjusted to 6.2 with aqueous ammonia, and the mixture was cooled to obtain 7.3 g of non-bitter sweet substances. Obtained as a precipitate.

Claims (1)

[Claims] 1. A method for extracting a sweet substance, which comprises extracting the underground part of a plant belonging to the genus Perianthra or a sweet substance-containing substance prepared therefrom with a water-containing hydrophilic organic solvent under conditions of pH 3. . 2 The underground parts of plants belonging to the genus Perianthra or sweet substance-containing substances prepared therefrom are extracted with a water-containing hydrophilic organic solvent under conditions of pH less than 3, and the resulting extract is extracted at pH 3.
A method for extracting a sweet substance, which is characterized by neutralizing the above and precipitating the sweet substance.