JPH0571598B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides stevioside or its sugar adduct,
The present invention relates to a method for purifying a licorice extract, glycyrrhizin, or a sugar adduct thereof. For more details, see N-
The present invention relates to a method for purifying these substances using a weakly basic ion exchange resin having methylglucamine as an exchange group. [Prior Art] Selective adsorption methods using non-polar synthetic adsorption resins having a giant network structure have been known for the purification of natural glycoside extracts. Various conventional techniques regarding stevioside and glycyrrhizin (licorice extract), which are natural glycosides useful as sweet substances, will be described below. 1 Stevia Stevioside is used as a natural sweetener extracted from the leaves of Stevia rebaudiana BERTONI (hereinafter abbreviated as stevia). To extract and purify stevioside from stevia leaves, dry stevia leaves are extracted with water or hydrous alcohol, and the resulting extract is purified. The following various methods have been proposed as methods for this purpose. A method for separating and removing insoluble substances produced by adding metal salts to an extract (JP-A-54-76600, JP-A-55-39731, JP-A-55-138372, JP-A-58
−212760). A method in which sweet components are selectively adsorbed onto a non-polar synthetic adsorption resin having a giant network structure, and then desorbed using an organic solvent or a water-containing organic solvent
-41900, JP-A-1983-41898, JP-A-57-
43659). A method in which sweet components or impurities are transferred by contacting the extract as it is or after concentration with an organic solvent such as an alcohol (Japanese Patent Application Laid-open No. 52-5800, Japanese Patent Application Laid-open No. 52-47961). Method for removing impurities using a dialysis membrane
−76600). A method for adsorbing and removing sweet ingredients or impurities on activated carbon, zeolite, etc. (Japanese Patent Application Laid-Open No. 75992/1983). Among the above methods, a typical purification method used industrially is to selectively adsorb sweet components on a non-polar synthetic adsorption resin with a giant network structure, and then desorb them with an organic solvent or a water-containing organic solvent. There is a way to do it. The synthetic adsorption resin referred to here is a porous non-polar polymer with a giant network structure manufactured by copolymerizing styrene and divinylbenzene, such as Amberlite XAD-2, -4, Diaion HP-10, etc. , -20, -30, -40, -50, etc. This method is characterized by the following points. By being able to selectively adsorb and separate sweet components from a dilute solution, the burden of concentration can be reduced. coloring ingredients,
Most of the hygroscopic components are non-adsorbent and are discharged together with the passing liquid. However, although it has great merits due to the above characteristics, it also has the disadvantage that it also adsorbs stevia odor components and bitter taste components, which are hydrophobic substances. α-Glucosyl stevioside, which is obtained by adding sugar to a stevia extract using cyclodextrin glucanotransferase (EC2.4.1.19), also has the disadvantage of remaining stevia odor and bitter components. In order to improve the taste quality of stevia sweetness, it is necessary to remove stevia odor components and bitter components. 2 Licorice Extract (Glycyrrhizin) Various proposals have been made to purify licorice extract (glycyrrhizin) using resins. For example, a method in which glycyrrhizin is adsorbed onto an anion exchange resin and treated with alkaline alcohol (Japanese Patent Publication No. 35-15875). A method for purifying a licorice extract to which an organic or inorganic acid salt has been added by passing it through a column of a nonpolar giant network polymer to adsorb glycyrrhizin (Japanese Patent Publication No. 139710/1983). A method for purifying glycyrrhizin by adsorbing it onto polyamide resin (Japanese Patent Publication No. 1987-8765). A purification method for glycyrrhizin in which glycyrrhizin is adsorbed onto a styrene/divinylbenzene copolymer resin with a giant network structure having tertiary amino groups, and then treated with alkaline water.
19435). Glycyrrhizin is brought into contact with an intermediate polar or non-polar synthetic resin adsorbent that has a large network structure under heating conditions, and then the adsorbent is treated with an inorganic or organic acid to strengthen the adsorption, and impurities are washed out with water. , a method for purifying glycyrrhizin in which glycyrrhizin adsorbed on an adsorbent is eluted with a water-containing organic solvent (Japanese Patent Application Laid-open No. 59-20222). A method for purifying glycyrrhizin characterized by adsorbing impurities by treating a crude glycyrrhizin aqueous solution with a synthetic adsorbent having a giant network structure at a pH in the range of 5 to 9, and eluting unadsorbed glycyrrhizin (Japanese Patent Publication No. 1983- 57637). However, the method of glycyrrhizin,
Although impurities can be bound to the anion exchange resin, alkaline alcohol is unsuitable for purifying glycyrrhizin because all of them are eluted. This method requires a large amount of organic solvent to elute the adsorbed glycyrrhizin because adsorption of glycyrrhizin is based on physical forces such as Van der Waals force based on the giant network structure of the resin. In addition, it is not an advantageous production method because an organic acid salt or an inorganic acid salt must be added. The method is
Since adsorption with glycyrrhizin is based only on weak amide bonds, the amount of glycyrrhizin adsorbed to the resin is very small, which increases the amount of resin and equipment, which is also unsuitable as an industrial production method. This method uses a large network structure with tertiary amino groups to increase the adsorption amount of glycyrrhizin, and is not suitable for separating and purifying glycyrrhizin from impurities. The method involves bringing glycyrrhizin into contact with a synthetic resin adsorbent under heated conditions, then treating it with an inorganic acid or organic acid, and then washing with water to remove impurities. It is not suitable as a purification method for glycyrrhizin because both impurities are adsorbed. In this method, when an aqueous glycyrrhizin solution is treated with a synthetic adsorbent at pH 5 to 9, glycyrrhizin is more difficult to adsorb than impurities, but a considerable amount of glycyrrhizin is adsorbed to the resin, resulting in a considerably low purification yield. [Problems to be Solved by the Invention] The present inventors have developed natural glycoside extracts or their sugar adducts, particularly stevioside or its sugar adducts, licorice extracts, glycyrrhizin or its sugar adducts, etc. Because the adsorption purification technology using non-polar synthetic adsorption resins or anion exchange resins does not solve the problem of insufficient separation or entrainment of odor components and bitter components, we newly developed a weak basic ion having N-methylglucamine as an exchange group. A method of bringing exchange resin into contact was investigated. [Means for solving the problem] As a result of various studies, we have determined that the sweet component of stevia or its sugar adduct, the stevia odor component, the bitter component, and the licorice extract (glycyrrhizin) or its sugar adduct. By bringing impurities (odor components, bitter components) into contact with a weakly basic ion exchange resin having N-methylglucamine as an exchange group,
We have discovered a method to selectively adsorb these components to dramatically improve the taste quality of stevia sweet components and their sugar adducts, and to improve the purity, color, and sweetness quality of glycyrrhizin or its sugar adducts. It is something. In contact with a normal type of basic ion exchange resin, glycoside components and impurity components (odor components, bitter components) cannot be separated because they behave in the same way and are adsorbed. The present invention will be further explained in detail below. Stevia extract is extracted from stevia leaves with water or a polar solvent, stevia extract saccharide is a product obtained by adding glycose to stevia extract using an enzyme, and licorice extract is extracted from licorice with water or a polar solvent. The licorice extract and the licorice extract sugar adduct refer to the licorice extract to which glucose has been added using an enzyme. When the natural glycoside extract is a stevia extract, the stevia sweet component is easily soluble in water and alcohol in a mixed state, but water extraction is industrially performed. As a method for purifying extracts, the method of utilizing non-polar synthetic adsorption resins having a giant network structure has made an epoch-making progress in purification methods in the past. This is the stevia sweetness component in the stevia extract, which is about 0.5~
Stevia sweetness components are almost selectively adsorbed onto a synthetic adsorption resin from a dilute concentration of 5%, and concentration and purification are performed simultaneously using organic solvents (methanol, ethanol).
This is a method of detachment. With the development of this method, the quality has improved significantly compared to the previous one, but the non-polar synthetic adsorption resin still has an unpleasant taste because it adsorbs strong hydrophobic components such as stevia odor and bitterness in addition to the sweet component of stevia. There is a problem that a considerable amount of ingredients remain. Also, α is a sugar adduct of stevioside.
- Glucosylstevioside also has the same problem that it still contains a considerable amount of taste components. In order to solve these problems, the present inventors investigated whether there is an ion exchange resin that selectively adsorbs stevia odor components and bitter components, but does not adsorb stevia sweet components and its sugar adducts. We have discovered an innovative method in which Stevia odor components and bitter components are selectively adsorbed by contacting them with a weakly basic ion exchange resin having glucamine as an exchange group at an SV of 0.3 to 3.0. This weakly basic ion exchange resin having N-methylglucamine as an exchange group was developed as a chelate resin that selectively adsorbs boric acid and borate. Functional group N
-The OH group at the Cis position of methylglucamine and boric acid form a complex compound that is used to remove boric acid. There are no examples of application to glycoside substances such as stevia. From the above results, the weakly basic ion exchange resin having an N-methylglucamine functional group is effective in separating the sweet component of stevia and its sugar adduct from the odor component and bitter component of stevia. Weakly basic ion exchange resins with N-methylglucamine functional groups include Amberlite IRA-743 (OH type), Diaion CRB-02 (OH type), and Duolite ES.
-371 (OH type), all of which are resins with the same structure. As for the resin loading amount of stevia sweetness component and its sugar adduct, the stevia odor component and bitterness component are removed by loading 100 g to 5 kg per resin amount, but the lower the resin loading amount, the better the taste quality. This is a good direction. Also, a suitable SV (flow velocity) is about 0.2 to 3.0. On the other hand, a weakly basic ion exchange resin having an N-methylglucamine functional group is also useful for separating licorice extract (glycyrrhizin) and its sugar adducts from odor components and bitter components. Until now, there have been no examples of application to glycyrrhizin and its sugar adducts. Amberlite IRA is a weakly basic ion exchange resin with N-methylglucamine functional group.
-743 (OH type) Diamond Ion CRB-02 (OH type),
Duolite ES-371 (OH type) is available, and both are resins with the same structure. Regarding the amount of resin loading of glycyrrhizin and its sugar adduct, odor components and bitter components are removed by loading 100 g to 5 kg per resin amount, but the smaller the resin loading, the better the color, purity, and taste quality. This is a good direction. Further, a suitable SV (flow velocity) is about 0.2 to 3.0. [Effect] The present inventors believe that there may be a method to utilize the long side chains of this resin to separate substances with the same adsorption power (basicity) through steric hindrance due to differences in molecular weight. Thought. The molecular weight of the sweet component of stevia is large, stevioside 804 and rebaudioside A966, and its sugar adduct has an even larger molecular weight and has a long N-methylglucamine functional group, making it difficult to approach the active site due to steric hindrance. On the other hand, the molecular weight of the stevia odor component and bitter component is estimated to be small, and it is thought that they can easily approach the active site.

[ka]

〔Example〕

Hereinafter, the present invention will be explained with reference to Examples. Example 1 100 g of dried stevia leaves were added with 1 part of water and extracted at 80°C for 6 hours. After separating the stevia leaves and the extract, 1 part of water was further added to the stevia leaves and extracted at 80°C for 1 hour, and then extracted again at 80°C for 1 hour. Stevia leaves and extract were separated. Thereafter, 1 portion of water was further added to thoroughly wash the stevia leaves at room temperature, and the stevia leaves and the washing liquid were separated. The extract obtained in this way and the washing liquid were combined to obtain a sweet dark brown extract with a solid content of 2.58 g.
37.7g, pH6.0) was obtained. After extraction, the stevia leaves had almost no sweet taste, and the sweet substances contained in the stevia leaves had been completely extracted. Next, the extract was allowed to stand for 3 hours to precipitate small pieces of Stevia leaves or stems, and the liquid layer was separated from the precipitate using a decanting method.
The solution was passed through a column filled with 400 ml of HP-20 (manufactured by Mitsubishi Kasei Corporation) at SV=3, and then washed with water by passing 1.2 ml of water therethrough. The wastewater generated at this time had a liquid volume of 3.39 and a pH of 6.7.
It was hot. After washing with water, add 2.3 SV of slaked lime saturated solution
= 2 and then 1.2 of water was passed for washing. Next, 70% ethanol 1.2 was passed through it at SV=3 to obtain a pale yellow-green eluate 1.25. After neutralizing the eluate with carbon dioxide gas, it was concentrated to remove and recover ethanol, and then the precipitated insoluble materials were removed, and the mixture was further concentrated and dried to give 15.2 g of a yellow powder with a slight odor (purity 69.9).
%) was obtained. Dissolve 15.2g of this yellow powder in 30ml of water and add 200ml of Amberlite IRA-743 (OH type).
The flow rate into a glass column (φ4cm x 30cm) packed with
The solution was passed at SV=1.0. Concentrate 300ml of the passed liquid to dryness.
12.5 g of slightly yellow powder was obtained. Analysis by liquid chromatography showed that the purity was 75%. A taste test was conducted by 10 panelists on the products treated with resin using Arborite IRA-743 (OH type) and those without resin treatment.

[Table] All 10 panelists gave the taste quality evaluations shown in Table 1. The reason why the sweetness of the sample treated with Amberlite IRA-743 (OH type) was higher than that of the blank is thought to be due to the improvement in the purity of the sample as the stevia odor component and bitter component were removed. Example 2 Amberlite obtained by the same method as Example 1
IRA-743 (OH type) 20g of yellow powder before resin treatment, 100g of maltodextrin (DE30) and 300ml of water.
After heating and dissolving the crude cyclodextrin glucanotransferase, it was cooled to 60°C.
1000 units were added, the pH was adjusted to 6.0, and the reaction was carried out at 60°C for 40 hours. The reaction solution was kept at 95°C for 10 minutes to inactivate the enzyme by heating, and then adsorbed on non-polar synthetic adsorption resin HP-20, washed with water and eluted with 90% methanol.
500 ml of eluent was obtained. Then, this eluate was desalted by passing it through ion exchange resins Amberlite IR200C (H type) and Amberlite IRA-93 (OH type) at SV=2. Then, this liquid was concentrated under reduced pressure at 70°C or lower and dried to obtain 30 g of α-glucosyl stevioside. Dissolve 30g of this α-glucosyl stevioside in 60ml of water and use Amberlite.
The solution was passed through a glass column (φ4 cm x 30 cm) packed with 300 ml of IRA-743 (OH type) at a flow rate of SV=1.0. 300 ml of the passed liquid was concentrated to dryness to obtain 25 g of purified α-glucosyl stevioside. A panel of 10 people conducted a taste test on the resin-treated and non-resin-treated Amberlite IRA-743 (OH type) samples.

[Table] All 10 panelists rated the taste quality as shown in Table 2. Example 3 Licorice chips are soaked in 5 times the amount of alkaline ammonia aqueous solution, extracted for 6 hours at room temperature, the extract is separated and the extraction is repeated twice. Dilute sulfuric acid is added to the obtained extract to adjust the pH to 2.0. . This was allowed to stand overnight and the precipitate was separated from the supernatant. The deposit is 10
The mixture was stirred and washed with twice the amount of water, filtered, dried at 60°C, and then ground. Ten times the amount of 95% methanol was added to this powder and extracted for 60 minutes under reflux cooling. After separating the extract, the methanol was recovered under reduced pressure to obtain a concentrated solution of glycyrrhizic acid. Caustic soda water was added to this concentrated solution to obtain an aqueous solution with a pH of 7.0. The purity of glycyrrhizin at this time was 35%. This glycyrrhizin aqueous solution 1 (solid content 200g)
was passed through a resin column filled with 3 weakly basic ion exchange resins (manufactured by Mitsubishi Kasei Corporation, product name: Diaion CRB-02 (OH type)) having a functional group of N-methylglucamine at a flow rate of SV = 1.0. The odor components and bitter components in the licorice extract were adsorbed onto the resin, and the eluted aqueous glycyrrhizin solution 4 was concentrated to dryness under reduced pressure to obtain 130 g of yellow glycyrrhizin.High performance liquid chromatography of the obtained glycyrrhizin The purity by E was 52%. The recovery rate of glycyrrhizin was 96.6%. A panel of 10 people conducted a taste test of the resin-treated and non-resin-treated products using Diamond Ion CRB-02 (OH type). did.

[Table] Example 4 100 g of yellow-brown glycyrrhizin (purity 35%) prepared in Example 3 and maltodextrin (DE18)
Add 100g of cyclodextrin glucanotransferase to 300g of water, dissolve, cool to 60°C and adjust the pH to 5.5, add 3000 units of crude cyclodextrin glucanotransferase,
The reaction was carried out for 40 hours while maintaining pH 5.5 and 60°C. This reaction solution was heated to inactivate the enzyme, filtered, 5 g of magnesia-based adsorbent was added to the solution, and kept for 20 minutes with gradual stirring.Then, the filtered solution was concentrated under reduced pressure and the solid content was 630 g of a tan reaction product of 30 w/w% was obtained. 630 g of this sugar-added glycyrrhizin aqueous solution was added to a weakly basic ion exchange resin having a functional group of N-methylglucamine (manufactured by Organo Co., Ltd., product name: Amberlite IRA-743 (OH type).
The odor components and bitter components in the glycosylated glycyrrhizin aqueous solution are adsorbed on the resin through a resin column filled with 3.5 glycyrrhizin at a flow rate of SV = 1.0, and the 4.5 saccharified glycyrrhizin aqueous solution eluted is concentrated to dryness under reduced pressure to form yellow saccharified glycyrrhizin. Obtained 120g. A panel of 10 people conducted a taste test on the resin-treated and non-resin-treated products using Amberlite IRA-743 (OH type).

〔Effect of the invention〕

As described above, according to the present invention, impurities of natural glycoside extract or its glycosylated product, especially stevia or its glycosylated product, licorice extract or its glycosylated product,
By separating odor components and bitter components, we were able to obtain highly pure, high-tasting glycosides or their sugar adducts, and we completed the production method.

Claims (1)

[Claims] 1. Stevia extract or its sugar adduct, licorice extract or its sugar adduct is contacted with a weakly basic ion exchange resin having N-methylglucamine as an exchange group, and the stevia extract is extracted. A stevia extract or a sugar adduct thereof, a licorice extract or a sugar adduct thereof, which is characterized by adsorbing and removing odor components and bitter components of either a licorice extract or a sugar adduct thereof, or a licorice extract or a sugar adduct thereof. Purification method.