KR100253423B1 - Process for purifying erythritol - Google Patents

Abstract

PURPOSE: Provided is a method for purifying high-purity erythritol in broth including strains that produce erythritol in a high yield without ion exchange resin or activated carbon to eliminate impurities. CONSTITUTION: A method for purifying high-purity erythritol in a high yield is characterized by the following steps of: i) cultivating strains that produce erythritol in a medium including glucose to obtain broth containing the strains and erythritol; ii) heating the broth at 60-80 deg.C and cooling it to make the strains and minute impurities coagulated; and iii) filtering coagulated matters with filtering membranes of 0.2-0.8μm in its size and separating erythritol from the matters. And the strains include Aureobasidium sp., Moniliella sp., Candida zeylanoides, Candida lipolytica, and Trichosporonoides madida.

Description

A process for purifying erythritol

The present invention relates to a method for purifying erythritol from a culture or cell separation solution of erythritol producing microorganisms.

Erythritol is a natural substance present in the body fluids of fermented foods, mushrooms, plants and mammals, and is 70-80% of the sweetened sugar. Erythritol is a low-calorie sweetener whose calories are less than 1/10 of sugar (0.3Kcal / g). It is endothermic when dissolved and has a cool sweetness and low hygroscopicity and colorability. In addition, the caries bacteria Streptococcus mutants are not available because they do not produce acids or glucans, so they also have non-cavities.

In addition, the general disadvantage of the conventional sugar alcohols are diarrhea when ingested in a large amount, but erythritol has a relatively low intake of diarrhea even when ingested in a relatively large amount.

Erythritol is usually obtained using erythritol producing strains using glucose as a medium. Specific manufacturing method is a method using the Aureobasidium genus strain (JP 61-31091), a method using the Moniliella genus strain (EP 0,136,805), a method using Candida zeylanoides ( JP 49-118889), the method using Candida lipolytica (USP 3,756,917), the method using Trichosporonoides madida (KP 957237), and the like.

The erythritol-containing culture solution obtained by culturing from the glucose medium using such an erythritol producing strain is usually purified by ion exchange resin by removing the colored material using activated carbon after removing the cells by centrifugation or the like, followed by concentration and crystallization. Erythritol is prepared. However, in general, the culture solution by culturing the erythritol producing strain generates proteins, peptides and other fine impurities in addition to erythritol, which requires a lot of purification load of the culture solution, and requires a large amount of ion exchange resin for purification, and is generated by regeneration of the used ion exchange resin. There is a disadvantage in that a large amount of waste water is generated.

On the other hand, in the concentrate of the liquid treated with the usual activated carbon treatment and ion exchange resin, fine impurities are coagulated and precipitated, and when the red crystals of erythritol separated from the concentrate are re-dissolved, a suspended substance exists. The conventional method of purifying the suspended substances and the like with fine impurities such as proteins and peptides produced in the culture solution is to filter the erythritol-containing culture medium obtained by culturing the erythritol producing strain with an ultrafiltration membrane separating molecular weight of 1,000 to 100,000 to obtain erythritol. Method of recovering (Japanese Patent Publication No. 7-34750), Method of recovering erythritol by passing the culture solution to a separation column filled with a strong acid cation exchange resin of Ammonium (Japanese Patent Publication (Hyeong) 7-34748 and Japanese Patent Publication 1-320987. However, the ultrafiltration apparatus is expensive and the flow rate of the ultrafiltration liquid is low, so it takes a long time to process and requires regular cleaning of the membrane surface. In addition, in the separation method using a strong acid cation exchange resin, the treatment solution is diluted, which takes a long time to concentrate, and also causes a problem such as a decrease in recovery rate.

Accordingly, the present inventors devote a lot of research to developing a new method of increasing the recovery rate of erythritol by removing the suspended substances generated in the concentrated crystallization of erythritol in the culture medium of the erythritol producing strain more economically and easily. come.

In the present invention, the culture solution of erythritol-producing bacteria obtained from glucose as a raw material is heat-treated at a temperature of 60 to 80 ° C. to aggregate the cells and impurities or to separate the cells from the culture medium. The present invention provides a method for producing erythritol, characterized in that the precipitates are separated by heat treatment to allow the mixture to stand at room temperature, and the precipitates are separated and then concentrated to obtain erythritol crystals.

The purification method of the present invention does not require an ion exchange resin or activated carbon to remove fine impurities, and simplifies the erythritol purification process by separating the precipitate from the cultured erythritol-containing culture solution by a simple heat treatment process and the use of a filtration membrane. By using a 0.8 μm filtration membrane, a process that can improve the disadvantage of low flow rate of the filtrate when using an existing ultrafiltration membrane is economically easy and provides a high purification yield.

The culture solution to be applied to the method of the present invention contains an erythritol obtained by culturing commonly used erythritol producing strains such as Oreobashidium, Monoliella, Candida Zyranoides, Tricosporonoides Madida and the like in a medium using glucose as a sugar. Culture medium.

In addition, the cell separation solution to which the method of the present invention is applied includes an erythritol-containing suspension or solution remaining after removing the erythritol producing strain from a culture solution according to the present invention by a commonly known separation method such as filtration.

The culture or cell separation solution according to the invention is carried out at 60 to 80 ℃ and heated to cool to room temperature. As the culture solution or the cell separation solution is cooled to room temperature, the cells and proteins and other fine impurities produced from the cells are aggregated and precipitated. However, when it is heated below 60 ℃, the aggregation of cells and protein is not good.At high temperature above 60 ℃, the amount of aggregation precipitates at higher temperature, but when it is heated above 80 ℃, the cooling time to room temperature becomes longer and discoloration of the liquid. This causing phenomenon occurs.

The present invention is explained in more detail in the following examples.

Example

Example 1

Tree, an erythritol-producing strain that is deposited on March 18, 1997 in a medium containing 400 g of glucose, 10 g of yeast extract and 1 g / l of urea, can be easily distributed to the Korea Microbiological Conservation Center. Inoculated with Cosporonoides Madida CJ-NT1 (KCCM 10098) and shaken at 32 ° C. for 3 days to obtain a seed culture solution. Then, put 20L medium into a 30L fermenter, add 1L of seed culture solution, and incubate for 4 days at aeration volume of 10 l / min, agitation speed of 400rpm, incubation temperature of 32 ° C, 190 g / l of erythritol, 10 g / l of glycerol, and other solids. After separating the cell culture 8L containing 15 g / l using a 0.2 μm diameter membrane membrane made of polysulfone, the erythritol-containing filtrate was concentrated and separated until the concentration of erythritol at 750 g / l at 70 ℃ separated Erythritol is redissolved in distilled water and separated by concentration and crystallization to an erythritol concentration of 850 g / l. The separated erythritol was dried at 60 ° C. to obtain 750 g. Part of the solution was dissolved in distilled water and adjusted to 300 g / l of erythritol, and the transmittance at 660 nm was found to be 93.1%. Protein concentration was analyzed according to the protein assay method of Bio-Rad using albumin as a standard solution. The result was 5.77 μg / ml.

Example 2

Cells and erythritol-containing culture broth obtained in the same manner as in Example 1 were heat-treated at 80 ° C. for 1 hour, cooled to room temperature to aggregate impurities such as cells and proteins, and separated using a 0.4 μm filtration membrane made of polysulfone. . The separated filtrate was concentrated and dried in the same manner as in Example 1 to obtain 768 g of erythritol. A portion of the solution was dissolved in distilled water and adjusted to an erythritol concentration of 300 g / l, and the transmittance was measured at 660 nm. The result was 100%. No suspended substance was detected.

Example 3

The erythritol-containing culture solution obtained in the same manner as in Example 1 was heat-treated at 50 to 80 ° C. for 1 hour, and then cooled to room temperature to measure the OD of the supernatant at 660 nm. The largest amount of coagulation precipitation occurred during heat treatment at 80 ° C.

Influence of temperature on heating cell separation liquid Temperature (℃) OD ₆₆₀ Before heating 0.184 50 0.184 60 0.179 70 0.146 80 0.119

In the method for purifying erythritol according to the present invention, the culture solution of erythritol producing cells is heat-treated at a temperature of 60 to 80 ° C. to induce agglomeration of cells or impurities, or the cell separation solution in which the cells are previously separated before heat treatment is heat-treated at 60 to 80 ° C. The process itself is not only simple but also the cost of the process can be considerably reduced compared to the conventional purification method because it consists of only a process of agglomerating impurities and filtering the aggregates thereof. And to be obtainable in high yield, which may be used quite advantageously in industry.

Claims (2)

After culturing the erythritol producing strain in a medium containing glucose to obtain a culture medium containing the cells and erythritol, the mixture was heated to a temperature of 60 ℃ to 80 ℃ and then cooled to agglomerate the cells and fine impurities, the resulting aggregates were filtered and removed A method for producing erythritol, characterized in that the separation of erythritol. The method of claim 1, further comprising the step of obtaining a cell separation solution from which the cells were previously removed from the culture medium before the culture medium was heat treated.