JPH0782287A - Purification of oligosaccharide - Google Patents

Abstract

PURPOSE:To easily purify oligosaccharides raised in the composition concentrations of triose or higher oligosaccharides from an oligosaccharides- contg. syrup and/or an aqueous solution of oligosaccharides-contg. powder with out the need of using any special equipment, etc. CONSTITUTION:Firstly, an oligosaccharides-contg. syrup and/or an aqueous solution of oligosaccharides-contg. powder is incorporated with an organic solvent followed by heating into a homogeneous solution. Secondly the lower layer of the two-layer separated liquid obtained by cooling the above solution is fractionatedly recovered, thus purifying the oligosaccharides raised in the content of triose or higher oligosaccharides. This purification method is hopeful of application in place of conventional methods using column chromatography. The oligosaccharide purified, which are hopeful of physiological effect, can be used as e.g. ingredients for various foods and beverages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying oligosaccharides, more specifically, industrially reducing and removing monosaccharides, disaccharides, etc. in an aqueous solution of oligosaccharide-containing syrup and / or oligosaccharide-containing powder. The present invention relates to a method for purifying oligosaccharides having an improved content of trisaccharides or higher oligosaccharides.

[0002]

2. Description of the Related Art In recent years, various oligosaccharides having a physiological effect such as an intestinal regulating effect, an improvement of intestinal flora, an inhibition of intestinal spoilage product, etc., having an intestinal bifidobacteria growth promoting function with the increasing health consciousness. Has been developed and commercialized. The market for various foods and drinks containing oligosaccharides is also expanding. In particular, when it is approved by the Ministry of Health and Welfare as a specified health food, it is possible to label the effect on the product, and oligosaccharides having various physiological effects have been developed because of the advantages such as improvement of the product value. ing. An oligosaccharide having such a physiological effect is generally a trisaccharide or more.

As a method for purifying a mixed saccharide containing monosaccharides to oligosaccharides, a column chromatography method has been generally adopted and industrialized. However, the column chromatography purification method has a drawback that large-scale capital investment is required and that running costs of resin regeneration or reverse regeneration, resin replenishment and renewal, electricity, water, etc. increase. Further, in the case of purifying a mixed saccharide, the sugar syrup as a raw material for purification must be diluted to an appropriate concentration for treatment, which complicates the process. Further, during the column chromatography treatment, it is inevitably diluted with water, so the column chromatography purification treatment product must re-concentrate a large amount of the purification treatment liquid, and a large vacuum concentration machine is also required. .

Further, a monosaccharide, which does not assimilate the desired oligosaccharide,
A method by microbial treatment of yeast or the like that utilizes only disaccharides such as sucrose and maltose has also been proposed. However, saccharides other than oligosaccharides are not industrially recovered, and in reality, they have not been carried out because microbial treatment requires a large amount of equipment and treatment cost.

Up to now, a method for purifying various mixed sugars using an organic solvent such as alcohol, specifically, by adding an organic solvent to a starch saccharified solution and mixing the mixture, the mixture is allowed to stand and oligosaccharides are the main components. There is proposed a method (Japanese Unexamined Patent Publication (Kokai) No. 62-118894) in which the upper polymerization layer and the lower layer containing a high-polymerization component as the main component are separated into two layers, and the high-polymerization component precipitated in the lower layer is removed. . However, the method of adding an organic solvent such as alcohol to such a polysaccharide to separate the precipitated high polymerization degree component is different from the method of separating two layers into a solution layer.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to increase the composition concentration of oligosaccharide components of trisaccharide or higher from mixed saccharides containing oligosaccharides in a simple manner without requiring large-scale special equipment. It is to provide a method for purifying oligosaccharides that can be used.

[0007]

According to the present invention, there is provided a method for purifying an oligosaccharide having an improved oligosaccharide content of trisaccharide or more from an aqueous solution of an oligosaccharide-containing syrup and / or an oligosaccharide-containing powder. , An oligosaccharide-containing syrup and / or an aqueous solution of an oligosaccharide-containing powder is added with an organic solvent to uniformly heat and dissolve, and after cooling, the lower layer of the obtained two-layer separated liquid is separated and collected. A purification method is provided.

The present invention will be described in more detail below.

In the purification method of the present invention, first, an organic solvent is added to an aqueous solution of an oligosaccharide-containing syrup and / or an oligosaccharide-containing powder, and the mixture is heated and uniformly dissolved.

The oligosaccharides contained in the aqueous solution of the oligosaccharide-containing syrup and / or oligosaccharide-containing powder include soybean oligosaccharides, fructooligosaccharides, isomaltooligosaccharides, xylooligosaccharides, galactooligosaccharides, milk oligosaccharides, and starch saccharification. Various oligosaccharides such as liquid can be mentioned. In the aqueous solution of the oligosaccharide-containing syrup and / or oligosaccharide-containing powder, the content concentration of the oligosaccharide containing the oligosaccharide is not particularly limited, but preferably 80 W / W% or less, particularly preferably,
It is possible to reduce the amount of organic solvent used, which will be described later. 7
It is preferably 0 to 80 W / W%. Content concentration is 80
If it exceeds W / W%, the viscosity becomes high and crystals are likely to precipitate, which causes a problem in industrial operability, which is not preferable.

The organic solvent to be added to the aqueous solution of the oligosaccharide-containing syrup and / or the oligosaccharide-containing powder is preferably one having a large difference in the solubility of the oligosaccharide depending on the temperature in the presence of water, particularly one having a high polarity and a large number of carbon atoms. Is effective. Specific examples thereof include alcohols such as methanol, ethanol, isopropanol and butanol; ketones such as propanone and methyl ethyl ketone; ethers such as ethyl ether; acetonitrile and the like, which may be used alone or as a mixture. it can. The amount of the organic solvent added varies depending on the type of the organic solvent, the heating temperature, etc., but the concentration at which the organic solvent dissolves uniformly when heated and uniformly dissolved, that is, an aqueous solution of oligosaccharide-containing syrup and / or oligosaccharide-containing powder The organic solvent can be added up to the maximum possible amount that does not become cloudy when heated. When an organic solvent is added in an amount more than the amount in which the aqueous solution of oligosaccharide-containing syrup and / or oligosaccharide-containing powder becomes cloudy in a heated state, the purification efficiency of oligosaccharides decreases,
It is uneconomical because the amount of organic solvent added increases.

Most preferably, the heating is carried out at a temperature around the boiling point of the added organic solvent.
Various temperatures at which the organic solvent can be uniformly dissolved can be selected according to the amount of addition and the like.

To add the above organic solvent and dissolve it uniformly by heating, for example, the heating temperature and the addition amount of the organic solvent are set in advance, and the organic solvent is added to the aqueous solution of the oligosaccharide-containing syrup and / or the oligosaccharide-containing powder. A method of adding and heating the clouded solution to a predetermined temperature to uniformly dissolve the organic solvent to make it transparent, while maintaining the heating temperature of the transparent solution, gradually adding the organic solvent to the maximum possible amount without clouding. Or a method in which an aqueous solution of oligosaccharide-containing syrup and / or oligosaccharide-containing powder is heated to a predetermined temperature and an organic solvent is added in an amount that does not cause cloudiness. In this case, in any case, it can be carried out under stirring, and water or the like can be added to dilute the solution.

Next, in the purification method of the present invention, the solution obtained by heating and uniformly dissolving is separated into two layers by cooling. The cooling may be performed at a temperature at which it is separated into two layers, and it is particularly preferable that it is about room temperature. In this way, the upper layer separated into two layers is a transparent liquid layer containing a large amount of monosaccharides, further containing disaccharides, and having a small content of oligosaccharides of trisaccharides or more,
On the other hand, the lower layer is a transparent or slightly cloudy liquid layer containing a small amount of disaccharides, monosaccharides, etc. but a large amount of trisaccharide or higher oligosaccharides. Thus, by separately collecting only the lower layer separated into two layers, and distilling off the organic solvent by, for example, concentration under reduced pressure, an oligosaccharide having a high content of oligosaccharides higher than the target trisaccharide is obtained from the lower layer. You can At this time, in order to further increase the oligosaccharide content of trisaccharide or higher,
It is also possible to repeat the steps of adding the organic solvent to the separated and recovered lower layer, heating and uniformly dissolving it, and cooling and separating.

[0015]

EFFECTS OF THE INVENTION In the purification method of the present invention, an oligosaccharide having an increased composition concentration of oligosaccharides of trisaccharides or higher is prepared from an aqueous solution of oligosaccharide-containing syrup and / or oligosaccharide-containing powder without using special equipment. Since it can be easily purified, it can be expected to be used in place of conventional column chromatography purification treatment. The purified oligosaccharide can be used as an additive component of various foods and drinks, expecting physiological effects and the like.

[0016]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited thereto.

[0017]

Example 1 Commercially available soybean oligosaccharide syrup (SOE) was added to R. Bri.
After preparing x40, 60, and 76, ethanol was uniformly dissolved in 50 g each at the time of heating at 60 ° C., and a critical amount was added so that a transparent liquid was obtained without clouding. Then, when cooled to room temperature, the liquid layer was separated into two layers, so the lower layer was separated and recovered, and the sugar composition of the lower layer solution was analyzed by high performance liquid chromatography (HP
LC). The results are shown in Table 1. The sugar composition of the soybean oligosaccharide syrup used in the sample was stachyose 22.1%, raffinose 11.4%, sucrose 41.
5%, glucose 10.0%, fructose 15.0%
Is.

[0018]

[Table 1]

From the results shown in Table 1, it can be seen that the syrup having an increased oligosaccharide content of trisaccharides or higher than that before purification was purified from any R. Brix soybean oligosaccharide syrup. It should be noted that when R. Brix is low, the separation rate of the lower layer portion is low, but it is understood that the purification efficiency of trisaccharides or higher is greatly improved.

[0020]

Example 2 Commercial soybean oligosaccharide syrup (R. Brix76)
To 50 g, ethanol was added in a critical amount so that ethanol was uniformly dissolved at each heating temperature shown in Table 2. Then, when the mixture was cooled to room temperature, the liquid layer separated into two layers. Therefore, after separating and recovering the lower layer, ethanol was added again to the lower layer solution in the limit amount capable of uniformly dissolving at each heating temperature shown in Table 2, and cooled to room temperature. After separating into two layers, the lower layer was separated and collected. The sugar composition of the recovered lower layer solution was measured in the same manner as in Example 1. The results are shown in Table 2.

[0021]

[Table 2]

From the results shown in Table 2, it can be seen that at any heating temperature, the syrup having an increased content of oligosaccharides of trisaccharides or more than that before purification was purified. It is also found that the higher the heating temperature, the higher the transfer of trisaccharides or more to the lower layer.

[0023]

[Example 3] Soybean oligosaccharide syrup (R.Brix76) 100
518 g of ethanol was added to 0 g, and heated to 75 ° C. with gentle stirring to obtain a uniform transparent solution. Then, the mixture was cooled to room temperature and allowed to stand for 2 hours, so that two layers were separated, so that 955 g of a lower layer liquid was recovered. The collected lower layer liquid is concentrated under reduced pressure (rotary evaporator, bath temperature 5
Treatment with 0 ° C., vacuum degree 700 mmHg, circulating cooling water temperature for condenser 5 ° C.) recovered 872 g of purified soybean oligosaccharide syrup (R.Brix76). The sugar composition of the recovered product was analyzed in the same manner as in Example 1. The results are shown in Table 3.

[0024]

[Table 3]

[0025]

Comparative Example 1 To 1000 g of the same lot of soybean oligosaccharide syrup (R.Brix76) as in Example 3 was added 518 g of ethanol, and the mixture was stirred at room temperature for 30 minutes and allowed to stand for 2 hours, whereby two layers were separated. Therefore, 1256 g of the lower layer liquid was recovered. The recovered lower layer solution was treated with a vacuum concentrator (rotary evaporator, bath temperature 50 ° C., vacuum degree 700 mmHg, circulating cooling water temperature for condenser 5 ° C.) to recover 953 g of purified soybean oligosaccharide syrup (R.Brix76). The sugar composition of the recovered product was analyzed in the same manner as in Example 1. The results are shown in Table 4.
Shown in.

[0026]

[Table 4]

Claims (1)

[Claims] 1. A method for purifying an oligosaccharide having an improved oligosaccharide content of trisaccharide or higher from an aqueous solution of an oligosaccharide-containing syrup and / or an oligosaccharide-containing powder, the method comprising:
Purification of oligosaccharides, characterized by adding an organic solvent to an aqueous solution of oligosaccharide-containing syrup and / or oligosaccharide-containing powder, heating and uniformly dissolving the mixture, and cooling and then separating and recovering the lower layer of the resulting two-layer separation liquid. Method.