Method for purifying allulose conversion reaction product

Abstract

The present invention relates to a method of purifying allulose and a method of preparing allulose using the method of purifying, and more specifically the purification method includes mixing allulose conversion product with powdered activated carbon and applying the solid-liquid separation to efficiently remove impurities.

Claims

1. A method of purifying an allulose conversion product, comprising: mixing the allulose conversion product with a powdered activated carbon having an average particle diameter of about 10 to about 44 um to produce a mixture, and obtaining a filtered solution by removing impurities and the activated carbon with solid-liquid separation for the mixture, wherein the solid-liquid separation is performed by passing through a filtering device including filter press and a filter aid having 10 to 500 um of particle size.

2. The method of claim 1, wherein the method of purification further comprises a step of ion purification with a column packed with ion exchange resin, after treating with activated carbon.

3. The method of claim 1, wherein the amount of mixed powdered activated carbon is 0.05 to 10 wt % based on 100 wt % of the total solid content of the allulose conversion product solution.

4. The method of claim 1, wherein the total solid content of the allulose conversion product solution is 0.5 to 80 wt %.

5. The method of claim 1, wherein the mixture solution is at a temperature of 30 to 90° C.

6. The method of claim 1, wherein the filter aid is at least one selected from the group consisting of diatomite, perlite, cellulose and ion exchange resin.

7. The method of claim 1, wherein the mixing the allulose conversion product with a powdered activated carbon is performed by stirring.

8. The method of claim 7, wherein the stirring rate is 5 to 500 rpm.

9. The method of claim 1, wherein the contacting time of allulose conversion product with a powdered activated carbon is 0.5 to 5 hours.

10. A method of preparation for allulose comprising: purifying the allulose conversion product to remove impurity, comprising mixing the allulose conversion product with a powdered activated carbon to produce a mixture, and obtaining a filtered solution by removing impurities and the activated carbon with solid-liquid separation for the mixture, separating the product with a simulated moving bed (SMB) chromatography to obtain a allulose fraction and a fructose raffinate, and concentrating or crystallizing the allulose fraction, wherein the solid-liquid separation is performed by passing through a filtering device including filter press and a filter aid having 10 to 500 um of particle size, with the mixture solution, and wherein the average particle diameter of powdered activated carbon is about 10 to about 44 um.

11. The method of claim 10, wherein the amount of mixed powdered activated carbon is 0.05 to 10 wt % based on 100 wt % of the total solid content of the allulose conversion product solution.

12. The method of claim 10, wherein the filtering device further comprise a filter aid that is at least one selected from the group consisting of diatomite, perlite, cellulose and ion exchange resin.

13. The method of claim 10, wherein the mixing the allulose conversion product with a powdered activated carbon is performed by stirring.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

(1) Hereinafter, the present invention will be described in more detail with the following examples. However, these examples are only for illustrative purpose, and the scope of the present invention is not limited by these examples.'

Example 1. Purification of Allulose Conversion Product (T %=78.6) with Mixing the Activated Carbon Powder

(2) 1 L of allulose conversion product (T %=78.6) at a concentration of 50 wt % was prepared in the flask, added with 0.5 wt % of powdery activated carbon based on the solid content and stirred at 75° C., 200 rpm for 1 hour. The powdery activated carbon used of samples 1 to 4 are shown in Table 1 and purchased from Norit activated carbon. Then, the activated carbon was removed by perlite filtration, and T % and turbidity (absorbance at 720 nm) of saccharide sugar solution treated with the activated carbon were measured in order to determine the discoloration and the removal of fine substances. The results are shown in Table 3.

(3) TABLE-US-00001 TABLE 1 Kind of activated carbon Average diameter Sample 1 45.4 μm Sample 2 44.2 μm Sample 3 27.7 μm Sample 4 18.5 μm

Comparative Example 1. Purification of Allulose Conversion Product (T %=78.6) with Mixing the Activated Carbon Particle

(4) 1 L of allulose conversion product (T %=78.6) at a concentration of 50 wt % was prepared in the flask, added with 0.5 wt % of powdery activated carbon based on the solid content and stirred at 75° C., 200 rpm for 1 hour. The powdery activated carbon used of samples 1 to 4 are shown in Table 2 and purchased from Norit activated carbon. Then, the activated carbon was removed by perlite filtration, and T % and turbidity (absorbance at 720 nm) of saccharide sugar solution treated with the activated carbon were measured in order to determine the discoloration and the removal of fine substances. The results are shown in Table 3.

(5) TABLE-US-00002 TABLE 2 Kind of activated carbon Average diameter Sample 5 1.25 mm Sample 6  1.1 mm

Example 2. Purification of Allulose Conversion Product (T %=70.4) with Mixing the Activated Carbon Powder

(6) 1 L of allulose conversion product (T %=70.4) at a concentration of 50 wt % was prepared in the flask, added with 0.5 wt % of powdery activated carbon based on the solid content and stirred at 75° C., 200 rpm for 1 hour. The powdery activated carbon used of samples 1 to 4 are shown in Table 2 and purchased from Norit activated carbon. Then, the activated carbon was removed by perlite filtration, and T % and turbidity (absorbance at 720 nm) of saccharide sugar solution treated with the activated carbon were measured in order to determine the discoloration and the removal of fine substances. The results are shown in Table 4.

Comparative Example 2. Purification of Allulose Conversion Product (T %=70.4) with Mixing the Activated Carbon Particle

(7) 1 L of allulose conversion product (T %=70.4) at a concentration of 50 wt % was prepared in the flask, added with 0.5 wt % of powdery activated carbon based on the solid content and stirred at 75° C., 200 rpm for 1 hour. The powdery activated carbon was the same as that of Comparative Example 1 and are shown in Table 2. Then, the activated carbon was removed by perlite filtration, and T % and turbidity (absorbance at 720 nm) of saccharide sugar solution treated with the activated carbon were measured in order to determine the discoloration and the removal of fine substances. The results are shown in Table 4.

Test Example 1. Analysis of T % and Turbidity for Allulose Conversion Product with Mixing the Activated Carbon

(8) The T % at 420 nm was measured using a UV spectrophotometer to determine the discoloration level of the allulose product solution treated with activated carbon according to Examples 1 and 2 and Comparative Examples 1 and 2. The sample to be measured had 30 Brix and analyzed using a 1 cm quartz cell. T % means the ratio of transmitted light to incident light. In contrast to absorbance, the value increases as the transmitted light increases. Therefore, the color is lighter and more transparent, as the value is high.

(9) The absorbance (abs) at 720 nm was also measured using a UV Spectrophotometer to determine the level of fine substances. The sample to be measured had a concentration of 30 Brix and analyzed using 1 cm quartz cell. After treating the activated carbon with allulose reaction solution which the initial T % and turbidity of the allulose conversion reaction solution were 78.6 and 0.032, T % and turbidity are analyzed and the result are shown in Table 3.

(10) TABLE-US-00003 TABLE 3 Kind of activated Turbidity Item carbon T % (720 nm) Example 1 Sample 1 96.1 0.003 Sample 2 97.9 0.003 Sample 3 98.1 0.003 Sample 4 98.4 0.002 Comparative Sample 5 87.6 0.008 Example 1 Sample 6 92.8 0.007

(11) After treating the activated carbon with allulose reaction solution which the initial T % and turbidity of the allulose conversion reaction solution were 70.4 and 0.024, T % and turbidity are analyzed and the result are shown in Table 4.

(12) TABLE-US-00004 TABLE 4 Kind of activated Turbidity Item carbon T % (720 nm) Example 1 Sample 1 93.8 0 Sample 2 96.6 0 Sample 3 97.0 0.001 Sample 4 97.4 0 Comparative Sample 5 84.2 0.006 Example 1 Sample 6 86.8 0.004

(13) As shown in Tables 3 and 4, when the activated charbon particles having various average particle sizes were mixed into the allulose reaction solution for purifying allulose, the particle size was the smaller, it was more effective to decolorize and easy to remove fine materials regardless of T % of the initial allulose reaction solution. When the activated carbons were mixed in a batch-type, the activated carbon particles might collide with the activated carbon particles during stirring, resulting in production of additional fine particles. As the powdery activated carbons have a large surface area, they have a large adsorption area with the colored materials and fine particles due to a large surface area, the smaller the amount of the activated carbon, the more effective the decolorization and the removal of the fine particles than the particulate activated carbon.

Comparative Example 3. Relation Between Impurity Removing Efficiency Using a Particle-Packed Column

(14) 122 g (250 ml) of the granular activated carbon of the sample 5 shown in Table 4 was filled in the column, and was flowed by the allulose reaction solution (T %=70.4) at a concentration of 50% by weight of allulose. At this time, the temperature of the column was 75° C. and the flow rate was SV 1 (250 ml/60 min=4.17 ml/min), and the pressure applied to the column was 0.04 MPa.

(15) SV refers to a value representing the processing efficiency of the fluid raw material in the continuous flow type reaction apparatus. When F [m.sup.3/h] is flow rate of the raw material and VR is inner volume of reaction apparatus, SV [h.sup.−1] of space velocity is represented by formula of Sv=F/VR. SV means the flow volume of raw material capable of supplying per unit time and unit volume of the reaction apparatus, and represented by unit of 1/h.

(16) As the column speed is the lower, the contact time between the activated carbon and the reaction solution is the longer. Therefore, the removal of the impurities is more efficient at the lower column speed, but the reaction solution treated per hour is decreased. In addition, the the column speed cannot be increased indefinitely and the pressure limit of the column used in the lab is 0.07 Mpa, so the column speed could not be increased any more.

(17) As an experimental result, the treatment efficiency of particle-packed column at various column speeds is shown in Table 5.

(18) TABLE-US-00005 TABLE 5 Pressure Solution amount treated Color index SV (MPa) per unit time (ml) (T %) turbidity SV 0.5 0.03 125 97.7 0 SV 1 0.04 250 95.5 0 SV 2 0.05 500 94.4 0 SV 3 0.06 750 90.2 0

(19) The experimental results of Comparative Example 3 using particle-packed column compared to Example 2 using activated carbon powder in a batch-type are shown in Table 6.

(20) TABLE-US-00006 TABLE 6 Powdered activated Granular activated carbon carbon Item (Comparative Example 3) (Example 2) Amount of activated carbon 122 g 2.5 g used per unit time Amount of reaction solution 750 ml 1 L processed per unit time Amount of reaction solution 6.15 ml 400 ml processed per 1 g of activated carbon Color index (T %) 90.2 97.4 Turbidity 0 0

(21) When a column packed with granular activated carbon is used, the treatment rate of reaction solution is low due to the pressure limit. Therefore, the amount of reaction solution to be treated to the used activated carbon is reduced so as to lower the yield. When the powdered activated carbon is used in a batch-type, the amount of reaction solution to be treated per unit time can be infinitely increased according to the reaction vessel without being affected by the pressure, and a small amount of activated carbon can achieve the large treatment effect.