JPH059080B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for separating maltose, and in particular to a method for obtaining an aqueous maltose solution containing almost no oligosaccharides from an aqueous maltose solution containing oligosaccharides (hereinafter referred to as maltose syrup) using a simulated moving bed. Recently, maltose, which has a low sweetness and has a body effect, has been attracting attention as a new sweetener. Starch syrup contains maltose and has been used as a food product since ancient times. With advances in enzymatic saccharification technology, it has become technically possible to increase the maltose content in starch syrup, and there is a desire to develop a method for separating high-purity maltose from starch syrup. In order to obtain high-purity maltose using maltose syrup made from starch saccharified liquid, it is necessary to separate and remove impurities such as oligosaccharides and glucose that have a molecular weight greater than maltotriose, such as maltotriose and maltotetraose. is necessary. Methods for chromatographically separating maltose from maltose starch syrup containing such oligosaccharides have been proposed in JP-A-57-209000 and JP-A-58-23799, but both are based on batch methods and are not efficient on a large scale. It is difficult to do well. The present inventors achieved a total sugar concentration of 30% by using a simulated moving bed.
As a result of deep investigation into a method for continuously obtaining high-purity maltose from maltose starch syrup, which has an oligosaccharide content of ~80% by weight and an oligosaccharide content of 5-60% by weight in total sugars, we found that The ratio of the volumetric flow rate of the circulating fluid to the apparent volumetric flow rate of the cation exchanger in the zone from the sorbate extraction section to the desorbent supply section φ ₂ and the concentration zone (from the sorbate extraction section to the raw material supply section) The ratio φ ₄ of the volumetric flow rate of the circulating fluid to the apparent volumetric flow rate of the cation exchanger in the zone of In order to obtain high-purity maltose with a small oligosaccharide content, the above-mentioned φ ₂ and φ ₄
It was discovered that it was necessary to operate the pseudo moving bed by adjusting the values to 0.3 to 0.5 and 0.3 to 0.6, respectively, and arrived at the present invention. In further detail, the present invention allows any type of simulated moving bed to be used to effect the separation of maltose. FIG. 1 is a schematic diagram of one example of a pseudo moving bed used in the method of the present invention, and FIG. 2 is a schematic diagram of another example. In FIG. 1, the inside of a packed bed 1000, which is the main part of the simulated moving bed, has 24
It is divided into unit packed beds. Each unit packed bed is filled with a salt-type cation exchanger that has a greater adsorption power for maltose than for oligosaccharides.
As the cation exchanger, various commercially available cation exchange resins or zeolites can be used. Usually, a strongly acidic cation exchange resin in which a sulfonic acid group is bonded to a crosslinked copolymer of styrene and divinylbenzene is used. Cation exchange resins are usually used in the sodium, potassium, or calcium form so that the difference between their adsorption power for maltose and oligosaccharides is large. In addition, as maltose starch syrup, the total sugar concentration is 30~
80% by weight, oligosaccharide content in total sugars 5-60% by weight
An aqueous solution of is used. There are spaces 1025 to 1048 between each unit packed bed.
are provided in each space, and a maltose starch syrup introduction pipe 1049 and a water introduction pipe 1 to the packed bed are provided.
050, maltose aqueous solution extraction tube 1051 and oligosaccharide aqueous solution extraction tube 1 from the packed bed
052, four types of pipes are open (however, the first
(Most of it is omitted in the figure). Although the provision of this space is not essential, it is preferable to introduce the maltose syrup introduced into the packed bed into this space because it can be quickly diffused into the liquid flowing down the bed. In FIG. 1, maltose starch syrup is introduced into the space 1048, and water is introduced into the space 1036. Further, the oligosaccharide aqueous solution is extracted from the space 1028, and the maltose aqueous solution is extracted from the space 1040. Therefore, the packed bed 1000 has 10
Adsorption zone consisting of 4 unit packed beds 01 to 1004, purification zone consisting of 8 unit packed beds 1005 to 1012, 1013 to 101
A desorption zone consisting of four unit packed beds of 6 and 1
It consists of four zones, a concentrating zone consisting of eight unit packed beds of 017 to 1024. The action of each zone is equivalent to each of the known simulated moving beds with maltose as the sorbing component and oligosaccharides as the non-sorbing component. The temperature inside the bed is usually 45-90℃ preferably
It is kept at 60-80℃. If the temperature inside the bed is higher than 90℃, the sugar solution that is extracted may become significantly colored. Furthermore, if the temperature is lower than 45°C, the viscosity of the maltose starch syrup increases, and the pressure loss within the bed increases. A maltose and oligosaccharide concentration distribution is formed in the liquid in the packed bed, and this concentration distribution moves downstream while maintaining its shape. To follow this movement, the pipes for introducing maltose starch syrup and water into the packed bed and the pipes for extracting the aqueous maltose solution and aqueous oligosaccharide solution from the packed bed are sequentially switched to the downstream pipes. The switching may be performed simultaneously for the four types of tubes, or may be performed at different times for each tube. The time for continuous introduction or extraction from the same pipe varies depending on the size of the unit packed bed, the type of cation exchanger, the flow rate of the liquid flowing down within the bed, etc., but is usually from several minutes to more than ten minutes. . By this switching, the four zones described above sequentially move their positions in the packed bed. However, the length of each band is always substantially constant. That is, each zone circulates through the packed bed while maintaining its size and relative position. The degree of separation of maltose and oligosaccharides in a simulated moving bed using a cation exchanger as a separation agent is influenced by various factors, but the most important factors are the flow rate of the liquid in the bed and the rate of flow of the liquid from the same tube. Time to continue introducing or extracting. This means that
Switching the liquid inlet and outlet pipes to the downstream pipes is as follows:
Looking at it from a different perspective, it is equivalent to moving the cation exchanger upstream while keeping the positions of the inlet and outlet tubes constant, and the sugar concentration distribution in the liquid in the bed moves in this upstream direction. This is also inferred from the fact that it is formed due to the interaction between the cation exchanger and the liquid moving downstream. As is well known, the flow rate of the liquid flowing down the bed differs from zone to zone. Of the flow rates in each of these zones, as mentioned earlier, the values of φ ₂ and φ ₄ have a large effect on the distribution of oligosaccharides into the maltose aqueous solution and oligosaccharide aqueous solution extracted from the packed bed. , these values are each
It is necessary to be 0.3-0.5 and 0.3-0.6.
In order to obtain more favorable results, the ratio φ ₁ and φ ₂ of the volumetric flow rate of the circulating fluid to the apparent volumetric flow rate of the cation exchanger in the adsorption zone (the zone from the raw material supply section to the non-sorbate extraction section) should be adjusted. The ratio (φ ₁ /φ ₂ )
It is desirable to be within the range of 1.2 to 1.7. If the value of φ ₂ or φ ₄ is not within the above range, the oligosaccharide will be distributed throughout the packed bed, and a large amount of the oligosaccharide will be mixed into the maltose aqueous solution that is extracted. However, if the above-mentioned conditions are satisfied, the oligosaccharides are distributed in the packed bed downstream of the adsorption zone, purification zone and concentration zone;
Almost no maltose is present in the desorption zone, so a highly pure maltose aqueous solution can be obtained. In this specification, the apparent volume flow rate of the cation exchanger is the apparent volume of the cation exchanger in the packed bed divided by the time required for the purification zone to go around the packed bed. However, if there are non-packed areas in the packed bed as shown in Figure 1, the purification zone will move around the packed bed by dividing the total volume of the liquid in these non-packed areas by the volume velocity of the liquid in the purification zone. The volume of cation exchanger in the packed bed shall be divided by the difference subtracted from the time required to do so. This unfilled part is installed for the purpose of dispersing maltose starch syrup as a raw material, but from the perspective of separation phenomenon, this part only causes a time delay and does not have an effective effect. Since this is just the cation exchanger itself, the validity of this correction calculation can be easily understood. Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In the following examples, "%" means "% by weight". Example 1 Using maltose starch syrup with a sugar concentration of 60% consisting of 1.3% glucose, 67.6% maltose, and 31.1% oligosaccharides as a raw material, maltose was separated using the apparatus shown in FIG. In Fig. 2, the unit packed beds 101 to 108 are cylinders with an inner diameter of 54 mm and a height of 600 mm, and inside the cylinder
Na-type strongly acidic cation exchange resin (Diaion
FRK-31, manufactured by Mitsubishi Chemical Industries, Ltd.) totaled 10.84
Filled. Each unit packed bed has a circulation pump 15
1 to 158, and a valve 111 is connected to the fluid passage connecting each unit packed bed.
Maltose aqueous solution extraction pipe 11 via ~118
0, an oligosaccharide aqueous solution extraction pipe 120 is installed through valves 121-128, a water introduction pipe 130 is installed through valves 131-138, and a maltose starch syrup introduction pipe 140 is installed through valves 141-148. The temperature inside the bed of the apparatus shown in Figure 2 was maintained at 75℃, and the supply amounts of maltose starch syrup and water were each 0.27℃.
/hr and 1.255/hr, and the extraction amount of maltose aqueous solution and oligosaccharide aqueous solution is 0.245 each.
/hr and 1.28/hr, and the flow rate control valve 109
As a result, the flow rates of the adsorption zone, purification zone, and concentration zone are 3.27/hr, 1.99/hr, and 3.00/hr, respectively.
It was adjusted so that In this case, for example, maltose starch syrup is added to the valve 14.
4, water is supplied through valve 138, and the aqueous maltose and oligosaccharide solutions are withdrawn through valve 112 and valve 126, respectively, into the desorption zone in packed beds 101 and 102 and in the desorption zone in packed beds 103 and 104. Enrichment zone, packed beds 105 and 1
Adsorption zone at 06, packed beds 107 and 10
A purification zone is formed at 8. Each valve is simultaneously switched to the downstream valve every 15 minutes, and each zone completes one cycle within the floor in two hours. In this example, φ ₁ , φ ₂ , φ ₄ and φ ₁ /φ ₂
The value of is as follows. φ ₁ =0.603 φ ₂ =0.367 φ ₄ =0.554 φ ₁ /φ ₂ =1.64 Table 1 shows the sugar compositions in the maltose aqueous solution and oligosaccharide aqueous solution extracted in a steady state.

[Table] Comparative Example 1 Using maltose starch syrup with a sugar concentration of 60.2% consisting of 1.1% glucose, 72.6% maltose, and 26.3% oligosaccharides as a raw material, maltose was separated in the same manner as in Example 1 under the following conditions.マルトース水飴供給量 0.380／hr 水供給量 0.672 〃 マルトース水溶液抜出量 0.380 〃 オリゴ糖水溶液抜出量 0.672 〃 吸着帯域の流量 4.765 〃 精製帯域の流量 4.092 〃 濃縮帯域の流量 4.385 〃 バルブ切替時間 616秒φ ₁ = 0.603, φ ₂ = 0.517 φ ₄ = 0.555, φ ₁ /φ ₂ = 1.16 Table 2 shows the sugar composition in each extraction liquid in steady state.
Shown below.

[Table] Example 2 Using maltose starch syrup with a sugar composition shown in Table 3 and a sugar concentration of 59.5% as a raw material, maltose was separated in the same manner as in Example 1 under the following conditions. Marutose syrup supply 0.268 / HR water supply weight 0.869 〃 Martose water solution extraction 0.332 〃 oligosaccharide solution 〃 抜 0 0 0 糖 糖 糖 糖 糖 糖 糖 糖 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯 帯φ ₁ = 0.593, φ ₂ = 0.480 φ ₄ = 0.555, φ ₁ / φ ₂ = 1.235 Table 3 shows the sugar composition in each extract in steady state.
Shown below.

【table】 [Brief explanation of the drawing]

FIG. 1 is a schematic diagram of one example of a pseudo moving bed used in the method of the present invention, and FIG. 2 is a schematic diagram of another example.

Claims (1)

[Claims] 1. An aqueous solution containing maltose and an oligosaccharide having a molecular weight higher than maltotriose as a raw material,
This is a method of continuous chromatographic separation using water as a desorbent into an aqueous solution of maltose, which is a sorbent component, and an aqueous solution mainly composed of oligosaccharides, which is a non-sorbent component. in a packed bed and connected to the front end by a fluid passage;
Adsorption zone from raw material supply section to non-sorbent extraction section,
The four zones are arranged in the above order from upstream: a purification zone from the extraction section to the desorbent supply section, a desorption zone from the supply section to the sorption extraction section, and a concentration zone from the extraction section to the raw material supply section. In a separation method using a simulated moving bed, which involves circulating a fluid while forming and intermittently moving the positions of the supply section and withdrawal section in the downstream direction, the raw material has a total sugar concentration of 30 to 80.
% by weight, and the oligosaccharide content in total sugars is 5 to 60
% by weight, and the ratio φ ₂ of the volumetric flow rate of the circulating fluid in the purification zone to the apparent volumetric flow rate of the cation exchanger is 0.3 to 0.5, and the volumetric flow rate of the circulating fluid in the concentration zone is the same as that of the cation exchanger. The ratio to the apparent volumetric flow rate of φ ₄ is 0.3 to 0.6
A method for separating maltose, characterized by: 2 Ratio of the volumetric flow rate of the circulating fluid in the adsorption zone to the apparent volumetric flow rate of the cation exchanger φ ₁
The method for separating maltose according to claim ₁ , characterized in that the ratio φ ₁ /φ ₂ of and φ 2 is 1.2 to 1.7.