KR920008387B1 - Method for producing oligo-saccharide - Google Patents

Abstract

A soybean oligosaccharide is prepd. by (a) diluting soybean whey to 20-50 Brix, (b) ultra-fitrating the diluted soybean whey wih cellulose- or ceramic membrane, (c) decoloring the ultrafiltrated soln., (d) desalting the decolored soln. and djusting the obtd. soln. to pH 7.0 at the same time, and (e) concentrating the soln. to obtain the finalproduct. The obtd. soybean oligosaccharide has a good taste.

Description

Manufacturing method of soy oligosaccharide

The present invention relates to a method for purely separating and purifying sugars contained in soybean whey, which is a by-product when producing soy protein for food ingredients.

Soy oligosaccharides are composed of stachyose, raffinose and sugar, containing about 5-10% of soybeans, and are resistant to acid and heat compared to fructooligosaccharides and malto oligosaccharides known to have similar functions. It is excellent and has a proliferation effect of Bifidus, which is an enteric useful bacterium. In addition, unlike oligosaccharides produced by the enzyme method, soy oligosaccharides are extracted from natural products and are highly evaluated in terms of their safety.

Conventional soybean oligosaccharide separation and purification methods are known in Japanese Patent Application Publications 59-179064 and 60-66978, and the acid is added to soybean husks to precipitate proteins and the supernatant is adjusted to pH 7-10 with calcium chloride and calcium hydroxide. There has been proposed a method of removing residual protein by a post heating step. However, this manufacturing method is difficult to industrial production because the amino acid and sugar react during the heating process, the sugar compounds are decomposed and the yield is lowered, and the whole process is complicated. On the other hand, the production method according to Japanese Patent Application No. 62-155082 is a method of extracting oligosaccharides by adding 20-60 V / V% of ethanol, methanol, or the like using skim soybean as a raw material. However, this manufacturing method also has a disadvantage that relatively high oligosaccharide content is contained in the degreased soybean, which is used as a raw material. There is difficulty in discoloration which is fair.

Therefore, the present inventors have studied new separation and purification methods to solve the problems caused by the existing manufacturing method, simplify the whole process, and increase the recovery of oligosaccharides.

The present invention uses soybean fry as a raw material, which is a by-product of the production of concentrated soybean protein, and soybean fry is a raw material that can be obtained inexpensively due to insufficient development of its use. The soybean husk was diluted with Brix (weight by weight total solids concentration) 2-50, preferably Brix 30-40 which is a suitable concentration, and then the raw material solution was prepared using an ultrafiltration membrane made of cellulose or ceracic. As a method of removing protein and other polymer impurities in the water, it has the following advantages over the conventional method.

First, while the conventional process requires at least 3-4 unit processes, the process according to the present invention is much simpler in terms of process rigidity since it can achieve the desired purpose in one step.

Second, the process according to the present invention can increase the recovery rate of oligosaccharides by preventing the decomposition of the sugar compound generated during heating by working at room temperature. In comparison with the conventional method, the yield of oligosaccharide was 74% and the yield of oligosaccharide was 82% according to the method of 62-155082. When the process was applied, an oligosaccharide yield of 98% was obtained.

Third, since the ultrafiltration separation of the water-soluble polymer impurities and some pigment components are also removed at the same time, the burden of desalting and decolorization, which is a subsequent process, is reduced.

Fourth, the conventional method requires a lot of energy consumption by repeated heating and cooling or a large amount of alcohol recovery, but the process according to the present invention requires the power only in the pump to apply pressure in the membrane separation, the energy saving advantages Have.

Fifth, all the conventional processes include a centrifugation process for precipitation of solids, so that it is difficult to continuously process the membrane, but the membrane separation method of the present invention has an advantage of easy operation because it is a continuous process.

As a result of examining various types of ultrafiltration membranes such as polysulfone, nylon, modified cellulose and ceramic, the modified cellulose series and ceramic series showed the best in terms of filtration flow rate. there was.

The pre-treated raw liquid is decolorized by passing through strong base anion exchange resin tower such as PA408, PA406, etc., and strong acid cation exchange resin, such as diion SK1B, Amberlite 1R-120, Duolite C-20, and strong base Deionization is carried out by passing through a mixed column in which aion exchange resins, such as diion PA408 or SA20AP, are mixed at a reasonable ratio, and at the same time, a purified solution is obtained by adjusting the pH. The soy oligosaccharide product is prepared by concentrating this solution in a syrup of Brix 70-76 in a condenser tube and performing ultraviolet sterilization.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

After diluting soybean hues properly, Brix 30-50 was adjusted to pH7, and the filtration flow rates of several membrane materials were measured at a temperature of 40 ° C. and a filtration pressure of 20 psi. The results are shown in Table 1 below.

TABLE 1

Comparison of Filtration Flow Rate by Membrane Material

Example 2

Dilute soybean whey with the composition as shown in Table 2 to Briggs 30-40 using 133 g of raw material, adjust the pH of the solution to 7, and then use a cellulose-based membrane that can remove substances with a molecular weight of 10,000 or more. The filtrate was recovered until the initial dilution was doubled at 40 ° C and a working pressure of 10 psi, and then distilled water was supplied at the same rate as the flow rate of the filtrate. The filtrate was recovered so that the final filtrate was 1.5 times the volume of the initial raw material diluent. More than 98% of the oligosaccharides were recovered. As for the recovery rate of oligosaccharide according to the final filtrate volume, it was appropriate to recover the filtrate about 1.5 times the volume to the initial raw material diluent as shown in Table 3. Since the recovered filtrate contains a large amount of dye, salt and soybean odor, it is decolorized using a strong base anion exchange resin DIION PA408 and a mixed phase column filled with 1: 1.5-2 volumes of DIION SK1B and SA20AP is used. After desalting, the product composition was obtained 46.4g of colorless and odorless syrup-like soy oligosaccharide as shown in Table 4.

TABLE 2

Soybean Huay Composition Table

TABLE 3

Recovery of Oligosaccharides by Final Filtrate Volume in Membrane Separation

TABLE 4

Product analysis

Example 3

Using soybean husk as a raw material, diluted to Brix 30-40, adjusted to pH7.0, and then operated at a temperature of 40㎏ and a pressure of 3.5Bar using a ceramic membrane to remove substances with molecular weight of 10,000 or more. The filtrate was recovered until the diluent was concentrated twice, and then the filtrate was recovered to the final filtrate volume as in Example 2 and bleached using anion exchange resin DIION PA408, followed by diion SK1B and SA20APFMF 1: 1.5 volume ratio. After desalting using a packed mixed column, 2.3 kg of syrup-like soy oligosaccharide was obtained through a condensation process.

Example 4

Table 5 shows the separation rate of the filtrate for each pH of the diluted raw material of Briggs 30-40 at a temperature of 30-40 ° C. and a pressure of 20 psi using a membrane made of the same material as in Example 3.

TABLE 5

Separation rate of filtrate by pH

Example 5

Table 6 shows the separation rate of the filtrate by operating pressure of the ultrafiltration membrane under the same conditions as in Example 3.

TABLE 6

Filtrate Separation Rate According to Ultrafiltration Operating Pressure

Claims (2)

Soybean oligosaccharide manufacturing method characterized in that the dilution of soybean whey (Whey) as a by-product in the production of concentrated soybean protein with Brix 20-50 and using an ultrafiltration membrane to remove polymeric impurities. The method according to claim 1, wherein a modified cellulose series or a ceramic series is used as the material of the ultrafiltration membrane.