JPH02303459A - Production of water-soluble dietary fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber consisting mainly of a partially degraded product of hemicellulose, low in viscosity when dissolved in water, easy to filtrate, to be used as an additive for bread, cake, etc., by alkali extraction of a plant fibrous material followed by treating the product extracted with xylanase. CONSTITUTION:A plant fibrous material (pref. corn husk, rice bran, wheat bran, barley bran, malt root or wood) is put to alkali extraction and the resulting product extracted is treated with xylanase (pref. alkali xylanase of bacteria origin) followed by pref. decoloration and then desalting, concentrating and drying, thus obtaining the objective dietary fiber consisting mainly of a partially degraded product of hemicellulose.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Field of Application J The present invention is directed to
The present invention relates to a method for producing water-soluble dietary fiber containing hemicellulose as a main component from rt raw materials.

[Prior Art J] In recent years, dietary fiber has attracted attention as a health food. This dietary fiber is mainly composed of cellulose, hemicellulose, lignin, pectin, etc., and is distinguished from conventional crude fiber (crude fiber), which is contained in plant cell walls and cell contents contained in grains. It is said to be a plant-based indigestible ingredient that can be used as a source of dietary fiber.The shell neck and outer skin of legumes (commonly called ``bran'' or ``bran'') are widely attracting attention as sources of such dietary fiber. It is becoming recognized that there is a correlation between increases and decreases in serum cholesterol, obesity, prevention of diabetes, appendicitis, and colon cancer1. It has drawbacks such as not melting, and even if it is pulverized, it loses its texture during the day.

For these reasons, attempts have been made to obtain water-soluble dietary fiber by extracting hemicellulose from the outer husks of grains and legumes. Hemicellulose can be extracted by treating the outer skin of grains and legumes with alkali. It has also been found that the hemicellulose extracted in this way exhibits an effect of suppressing the increase in serum cholesterol (Japanese Patent Publication No. 1689/1989 pQ).

[Problem to be solved by the invention] However, hemicellulose obtained by alkaline extraction has a considerably high viscosity even in a small amount when dissolved in water. It has the disadvantage that it is easily damaged and becomes a hindrance in manufacturing processes such as filtration.

In addition, attempts have been made to obtain water-soluble dietary fiber by acid-treating or blasting the ff necks and outer skins of beans, or by enzymatically treating them. Since it is broken down into oligosaccharides, there is a problem in that it is no longer considered dietary fiber.

Therefore, it is an object of the present invention to
The purpose of the present invention is to provide a method for producing a water-soluble food base J (L), which contains hemicellulose, which has a low viscosity when dissolved in water, as a main component and contains few monosaccharides and oligosaccharides, from m-quality raw materials.

[Means for Solving the Problems] In order to achieve the above objects, the method for producing water-soluble dietary fiber of the present invention comprises extracting Wi-fiber material*:1 with alkali, and treating the extract with xylanase. , which is characterized by obtaining a partial decomposition product of hemicellulose.

Hereinafter, one preferred embodiment of the present invention will be described in more detail.

In the present invention, agricultural and forestry wastes containing xylan, such as grain husks, malt roots, and wood, are preferably used as the plant fibrous pieces ft+.
Those prepared by removing lipids, inorganic substances, etc., ie, those containing cellulose and hemicellulose as main components and containing some lignin, are more preferably used. Here, as the grain husk, for example, corn husk, rice bran, wheat bran, barley bran, etc. are preferably used.

Enzyme treatment, chemical treatment, physical treatment, etc. can be used to remove starch, protein, lipids, minerals, etc. from raw materials such as grain hulls, malt roots, and wood.
Moreover, these may be processed in combination.

Examples of enzyme treatment include starch degrading enzymes such as a-amylase and glucoamylase, lipid degrading enzymes such as lipase,
Fibers such as cellulase #! Hydrolyzing enzymes at pH 3 to 9. Examples include a method of treating at a temperature of 30 to 100°C. Chemical treatments include adding an aqueous solution of mineral acid, organic acid, etc. to the raw material and heating it under conditions of PI (2 to 5), and adding a food grade surfactant to the raw material to produce p+
Examples include the 7j method in which heat treatment is performed under the conditions of i3 to i8. Furthermore, as the physical treatment, a method of pulverizing the Example λ-Bahara 14 with a pulverizer such as a homogenizer or a hammer mill, and then sieving it, etc. can be mentioned.

The method for alkali extraction of the plant fibrous pieces 11 can be carried out by a known method 2. For example, the above-mentioned plant fibrous raw material is suspended in an alkaline aqueous solution such as sodium hydroxide or calcium hydroxide, and then extracted at a predetermined temperature and As a preferable example, 0.8 parts by weight of calcium hydroxide, 1 part by weight of water, and 1 part by weight of vegetable fiber source $Hoo are added to 100 F
) by weight and treated at 125° C. for 15 minutes to extract hemicellulose.

The extract treated with alkali in this way is preferably 50 to 50%
After cooling to 60° C. and adjusting p)I with sulfuric acid, hydrochloric acid, etc. as necessary, xylanase is added and reacted. The addition of xylanase 1 is preferably about 06001-1 D units per 1 g of solid content of the extract, and the reaction time for 1 is:
About 3 to 6 hours is preferable.

The titer of xylanase was measured as follows: using hemicellulose extracted from corn with alkali as a substrate, reducing sugar equivalent to 1 micromole of xylose per minute under reaction conditions of pH 1 and 60°C. The amount of enzyme that produces is defined as 1 unit.

The xylanase used in the present invention is preferably a liquefied type rather than a saccharified type, and both fungal and bacterial origin xylanases can be used, but bacterial origin xylanase is more preferred because of its higher purity.

In addition, xylanase has an optimum pH for one action, ranging from acidic to alkaline, and any of them can be used by adjusting the pH as necessary, but the pH of the extract
Since i is alkaline, the optimum pH is on the alkaline side.
More preferable are alkaline xylanases having
-13357.

This alkaline xylanase is different from normal xylanase in p
While the optimum po is on the acidic side of if4-5, the working pH range is wide from neutral to alkaline, so there is no need to adjust the pH after alkaline extraction, or only a small amount of acid can be used. It has strong heat resistance and is easy to use.

In the present invention, in addition to the above-mentioned ordinary xylanase and alkaline xylanase, commercially available cellulases containing xylanase may be used alone or in combination with the above-mentioned xylanases. For example, Cellulase manufactured by Zenenko Co., Ltd. Since the activity as a xylanase is also observed in the following, it can be used as the xylanase of the present invention.

The reaction solution obtained by reacting the alkaline extract with xylanase is heated, for example, to inactivate the enzyme, and then
A water-soluble dietary fiber containing hemicellulose as a main component can be obtained by separating solid and liquid by centrifugation, clarifying filtration as necessary, decolorizing, desalting, concentrating, and drying.

In addition, the extract obtained by treating the plant fibrous material 4 with alkali is subjected to solid-liquid separation, clarification and filtration, and then PI preparation and treatment with xylanase to deactivate the enzyme and decolorize it.

It can also be desalted, concentrated and dried.

The above-mentioned method of treating with xylanase immediately after alkaline treatment lowers the viscosity of the reaction solution.

It has the advantage that the work following solid-liquid separation becomes easier and a highly viscous extract can be efficiently recovered.In addition, the method of treating with xylanase after the two solid-liquid separations described below has the advantage that pl (easy to adjust) It has the advantage that the amount of enzyme required is small.

The water-soluble dietary fiber mainly composed of hemicellulose thus obtained has high purity and can be expected to have excellent physiologically active effects even in small amounts. In addition, it is water-soluble and has a low viscosity when dissolved in water, so it can be added to drinks etc. without affecting the texture.
I will never be disappointed.

"Function" The present invention processes hemicellulose extracted with alkali from 1M textile fibrous raw material with xylanase to reduce the molecular weight, so water-soluble dietary fiber whose main component is hemicellulose cut into 7-degree blocks is produced. Obtainable. Furthermore, since this hemicellulose has not been reduced to the level of monosaccharides or oligosaccharides, it maintains its physiologically active function as a dietary fiber and can have a low viscosity when dissolved in water. Further, by reducing the viscosity as described above, manufacturing processes such as filtration are also facilitated.

Example J Example 1 100 parts by weight of corn husk, 1000 parts by weight of water,
1 weight 1 part of calcium hydroxide was heated at 85°C for 3 hours, cooled to 60°C, sulfuric acid was added to adjust the pH to 7, and then alkaline xylanase was added per 1g of solid content of the reaction solution. 0. One unit of O was added and the reaction was carried out for 48 hours.

In addition, alkaline xylanase was developed by the Japanese Patent Publication No. 50-13'3
57 was similarly prepared and used. Next, the enzyme was deactivated by heating at 90°C for 30 minutes, followed by solid-liquid separation, clarifying filtration, decolorization, and desalting. It was purified and dried with a spray dryer to obtain a powder. This powder, A
As measured by the OAC Brosky method, dietary fiber was 85.
%Met.

Example 2 100 parts by weight of corn husk, 1000 parts by weight of water,
Add 0.8 parts by weight of calcium hydroxide to 1 at 125°C.
After heating for 5 minutes, cool, add 500 parts by weight of warm water,
Solid-liquid separation was performed by centrifugation to obtain a filtrate.

The pH of the filtrate was then adjusted to 5.5 and the pH of the filtrate was adjusted to 0.
．． Add 1% cellulase (manufactured by Zenenko) and heat at 50°C.
The mixture was reacted for 24 hours to obtain a reaction solution. The enzyme in this reaction solution was deactivated and purified in the same manner as in Example 1.

It was dried to obtain dietary fiber powder.

Next, the reduction in viscosity due to the enzyme treatment in Example 1.2 was tested.

(1) Measurement of viscosity of slurry In Example 1, after alkali extraction of the raw materials, the viscosity of the reaction liquid before and after treatment with alkaline xylanase was measured as follows.

After cutting off the tip of a volumetric pipette and aspirating the sample, the time required for 5 ml to be transferred at room temperature was measured.

The results are shown in Table 1.

Table 1 Thus, it can be seen that the viscosity is reduced by treatment with alkaline xylanase.

(2) Measurement of filterability After performing the same operation as in Example 2 and extracting the raw material with alkali,
Add alkaline xylanase, cellulase (manufactured by Zenenko), and α-amylase to the filtered liquid.

Add each camphor enzyme of neutral protease and adjust the optimum pl+ for each.
Below, the reaction was carried out at 50°C overnight. In addition, as a comparative example, one without the addition of enzyme was also prepared. IO+ each reaction solution
14. Collect ml and pass it through a 0.45μ Millipore filter.
9c), filter for 2 minutes, 2I! The amount of liquid was measured.

The results are shown in Table 2.

(Hereinafter, blank spaces) Table 2 It can be seen that the filterability is significantly improved by treating the extract with alkaline xylanase and cellulase.

(3) Viscosity of the product The food wtm prepared in Example 2 and the dietary fiber prepared in the same manner as in Example 2 except that the enzyme treatment was not performed were added to water at a concentration of 5%. Dissolve,
The viscosity of each aqueous solution at 50'C was measured using a B-type viscometer (60
rpm, ). The results are shown in Table 3.

(The following is a blank space) Table 3 Thus, it can be seen that the viscosity of the product is significantly reduced by enzymatic treatment.

"Effects of the Invention" As explained above, according to the present invention, hemicellulose can be appropriately reduced in molecular weight by treating the plant fibrous raw material with xylanase after alkali extraction.

Therefore, it has a low viscosity when dissolved in water, which facilitates manufacturing processes such as filtration, and when added to drinks etc., increases in viscosity can be suppressed to prevent deterioration of texture. Furthermore, since the main component is hemicellulose, which has been reduced to a moderately low molecular weight without being decomposed into monosaccharides or oligosaccharides, excellent physiologically active effects can be expected even in small amounts. Therefore, the water-soluble dietary fiber obtained in the present invention is
It can be widely used as an additive in various foods and drinks, such as breads, cakes, and biscuits, as well as sauces, soups, and drinks.

Claims (5)

[Claims] (1) A method for producing water-soluble dietary fiber, which comprises extracting a plant fibrous material with alkali and treating the extract with xylanase to obtain a partially decomposed product of hemicellulose. (2) The method for producing water-soluble dietary fiber according to claim 1, wherein at least one selected from corn husk, rice bran, wheat bran, barley bran, malt root, and wood is used as the vegetable fiber raw material. (3) A claim in which the vegetable fiber raw material is at least one selected from corn husk, rice bran, wheat bran, barley bran, malt root, and wood, from which starch, protein, lipids, inorganic substances, etc. have been removed. 1. The method for producing water-soluble dietary fiber according to 1. (4) The method for producing water-soluble dietary fiber according to any one of claims 1 to 3, wherein alkaline xylanase of bacterial origin is used as the xylanase. (5) Claim 1 in which the alkaline extract is treated with xylanase, then decolorized, desalted, further concentrated and dried.
5. The method for producing water-soluble dietary fiber according to any one of 4 to 4.