JP5170725B2 - Method for producing water-soluble saccharide - Google Patents

Description

ここで単糖から５糖までの量は、標準物質を用いた検量線法によるイオンクロマトグラフ分析法より求め、リグニン量は第２画分の３％硫酸不溶分量として求めた。また、多糖量は第２画分量から単糖から５糖までの量、及びリグニン量を差し引いた値として求めた。加圧熱水温度が低いほど高分子多糖の割合が多くなるが、混入リグニン量の割合は低下することが示された。このように水溶性食物繊維に相当する成分の割合が多いのが本法の特徴である。また熱水温度が高いほど第２画分収率は高くなるが、これはリグニンの分解も進み、その結果、低分子化されたリグニンが糖類と共に流出してくるためである。
【００３８】
【実施例３】
試料として、ケナフ、イナワラ、麦ワラ、もみ殻を用い、操作圧力３．０MPaにて１２０℃で２０分間第１画分を抽出除去した後、１９８℃付近で２５分間第２画分の分解抽出を行った。その時の第２画分の収率、及び第２画分中における単糖から５糖（単−５糖）のそれぞれの濃度を表２に示す。
【００３９】
【表２】

イナワラ、麦ワラ、もみ殻の場合、糖成分としてアラビノースも得られた。ケナフやワラ類の場合、第２画分収率は４０％台と高いが、単糖−５糖の割合が１０−１５％と比較的低いのに対し、もみ殻では第２画分収率は３２％と低いが、単糖−５糖の割合は約２５％と非常に高いことが特徴的であった。
【００４０】
【発明の効果】
本発明の水溶性糖類の製造方法は、ヘミセルロースを含む植物から、健康食品として有用な食物繊維からオリゴ糖、単糖までをバランス良く含む水溶性糖類を加圧熱水のみを使用して安全かつ効率良く製造することができる。
【図面の簡単な説明】
【図１】図１は、水溶性糖類の製造装置の概要を示すものであり、熱水のフロー図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a water-soluble saccharide useful as a health food by hydrolyzing hemicellulose constituting a cell wall of a plant. More specifically, a well-balanced dietary fiber that has an action to bind to harmful substances such as oligosaccharides with high intestinal bifidobacteria growth activity and intestinal regulation, cholesterol, bile acids, or causative agents of colon cancer. The present invention relates to a method for producing foods and drinks of water-soluble saccharides that efficiently and safely produce the water-soluble saccharides contained therein.
[0002]
[Prior art]
An oligosaccharide refers to a combination of a plurality of monosaccharides, generally 2 to 6, and a polysaccharide having more, more often 10 or more bonds, is referred to as dietary fiber. Oligosaccharides include various oligosaccharides such as galactooligosaccharides, fructooligosaccharides, xylo-oligosaccharides, malto-oligosaccharides, and soybean oligosaccharides, depending on the type of monosaccharides that compose them. ing. However, these oligosaccharides have no physiological activity as dietary fiber. On the other hand, when the number of monosaccharide bonds is large, particularly 10 molecules or more, physiological activities as dietary fibers such as an inhibitory effect on serum cholesterol elevation, an effect of reducing liver damage, and an inhibitory effect on the occurrence of colon cancer are expressed.
[0003]
As a method for producing oligosaccharides, other than the extraction method in the production of soybean oligosaccharides, a method of making an enzyme act on a polysaccharide raw material such as starch or hemicellulose is generally used, and a steaming / explosion method and an enzymatic decomposition method are also used. A method combining the above has also been proposed (Patent Document 1, etc.). On the other hand, dietary fiber is a polysaccharide contained in many foods such as vegetables, fruits, sugars, moss, seaweeds, but is mostly water-insoluble except for some polysaccharides with a highly branched structure, In this state, the binding efficiency with harmful substances in the intestine is low.
[0004]
In order to make this water-insoluble polysaccharide water-soluble, there is a method of hydrolyzing various sugar raw materials using acid, alkali, catalyst or enzyme, but when acid or alkali is used, removal of the catalyst When using enzymes, there are many problems such as expensive enzymes and slow reaction rates. Furthermore, the hydrolysis reaction itself is difficult to control, and most of the molecular weight distribution is oligosaccharide (di-hexasaccharide), and the dietary fiber content is reduced.
[0005]
The inventors of the present invention have proposed a technique for decomposing hemicellulose and the like from biomass using only pressurized hot water (Patent Document 2), but this proposal did not use these decomposed products as a whole for food and drink.
[0006]
[Patent Document 1]
JP-A-9-248153 [Patent Document 2]
Japanese Patent Laid-Open No. 2002-59118
[Problems to be solved by the invention]
The present invention has been made based on the technical background as described above, and achieves the following object.
[0008]
It is an object of the present invention to produce a water-soluble saccharide containing a hemicellulose-containing water-soluble saccharide in a well-balanced manner from a dietary fiber useful as a health food to an oligosaccharide or a monosaccharide, using water alone, safely and efficiently. It is in providing the manufacturing method of.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention employs the following means.
[0011]
The method for producing the water-soluble saccharide of the present invention comprises:
In the method for producing a water-soluble saccharide produced from a plant containing hemicellulose,
To the plant, a soluble substance other than sugar in the plant is washed away with pressurized hot water having a temperature of room temperature to less than 140 ° C. and a pressure of 3 MPa for 20 minutes,
By contacting the plant from which soluble substances other than sugar in the plant have been washed away with pressurized hot water at a temperature of 140 to 230 ° C. and a pressure of 3 MPa for 25 minutes to hydrolyze the plant containing the hemicellulose. Water-soluble lignin with radical scavenging ability , oligosaccharides from monosaccharides, and water-soluble saccharides including polysaccharides in the category of dietary fiber are extracted.
[0016]
Plants Plants referred to in the present invention are woods such as conifers and broadleaf trees, agricultural waste such as rice husks and straws, or vegetation such as kenaf and tea leaves (including tea leaves after extraction of cited green tea). Means. Pressurized hot water is used as a reaction field (liquid) for hydrolysis to extract water-soluble saccharides having radical scavenging activity from plants. Therefore, since the hydrolysis reaction rate is directly related to the contact frequency with water molecules, particles pulverized to about 12 mesh are preferred. However, it may be hydrolyzed with pressurized hot water as it is without being pulverized, such as rice husk and tea leaves.
[0017]
Pressurized hot water The pressurized hot water of the present invention is used as a reaction field for extracting a water-soluble saccharide having radical scavenging activity from a plant by hydrolysis. Therefore, the pre-treatment and post-treatment with acid, alkali, enzyme, etc. are not denied in the treatment before and after this. Further, the meaning of the pressurized hot water 140 to 230 ° C. means that when the temperature is lower than 140 ° C., the decomposition of hemicellulose does not occur, and when the temperature is higher than 230 ° C., the decomposition of the cellulose starts, and the secondary sugar of the obtained saccharide. Since decomposition also occurs, it is limited to this range because it is not preferable. The vicinity of 140 ° C. is a transition region for the hydrolysis of hemicellulose, and is an ambiguous temperature region that takes a very long time even if it decomposes in a small amount.
[0018]
The exact decomposition starting temperature varies depending on the constituent sugar and the three-dimensional structure of hemicellulose derived from the plant. The pressure of the pressurized hot water is not limited to the saturated vapor pressure at that temperature of 1.0 to 3.0, and can be produced at a pressure higher than that, but the pressure resistance strength of the production apparatus, the pump This is a practical value determined by the pressure capacity of
[0019]
Treatment time The time for the soluble substance of the plant to be washed away by the pressurized hot water is 10 to 30 minutes at the room temperature to less than 140C, and 0.5 to 30 minutes at 140 to 230C. It was said that. This time is a general guide. For example, at room temperature, the production efficiency is low, but it may be 30 minutes or longer. In addition, in the case of extraction at 140 to 230 ° C., the concentration of the decomposed product has a peak value, and the concentration rapidly decreases after that. Therefore, the time for the soluble substance to flow out of the plant has a property that the optimum numerical value should be determined according to the shape, structure, capacity, etc. of the system.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a manufacturing apparatus used for manufacturing the water-soluble saccharide of the present invention will be described. FIG. 1 shows an outline of an apparatus for producing a water-soluble saccharide and is a flow diagram showing a flow of hot water. As water for producing the pressurized hot water, tap water or the like is supplied from the water supply pipe 1. The supplied water is made up of an ion exchanger, a filter, and the like, and is passed through a cartridge-type deionizer 2.
[0021]
The pure water filtered by the pure water device 2 is supplied to the pure water tank 3 and stored. Pure water stored in the pure water tank 3 made of polyethylene is sucked by a stainless steel pump 4 and sent to a buffer tank 5 which is a stainless steel container. The capacity of the pump 4 can be pressurized up to 6.5 Mpa in this example. The buffer tank 5 is for stabilizing the pressure and flow rate of pure water supplied to the reactor 10. A safety valve 6 that operates at 3.0 MPa and a nitrogen cylinder 7 are connected to the buffer tank 5.
[0022]
It is intended to replace air in the system and check for leaks. Water from the buffer tank 5 is supplied from the pipe 8 to the heat exchanger 9. Since the heated heat medium oil is supplied to the heat exchanger 9, water is heated by the heat of the heat medium oil to become pressurized hot water. The pressurized hot water is supplied to the reactor 10 through a valve or the like. The reactor 10 is a kind of pressure cooker for extracting the water-soluble saccharide of the present invention. The reactor 10 is made of stainless steel and has a hollow cylindrical shape, and is installed in the vertical direction in this example.
[0023]
Stainless sintered filters 14 are fixedly disposed on the upper and lower end surfaces of the reactor 10. The sintered filter 14 has holes with an average of 20 μm. The pore size need not be specific, but is preferably 5 to 30 microns on average. When the average is 30 microns or more, a fine sample flows out, and when the average is less than 5 microns, resistance when supplying hot water increases.
[0024]
As for the raw material plant charged into the reactor 10, those having a pore size larger than this will not flow out. A heating circuit 11 for circulating heat medium oil for heating the reactor 10 is connected to the outer periphery of the reactor 10 by a pipe. The heating circuit 11 is heated at 300 ° C. or 230 ° C. in the present embodiment. That is, after pure water is heated by the heat exchanger 9, it is sent to the outer jacket 13 disposed on the outer peripheral surface of the reactor 10.
[0025]
The outer jacket 13 is a heat exchanger for heating the reactor 10 with heat medium oil from the outside. An electric heater 16 is installed in the heat medium oil heater 15 that sends the heat medium oil to the heat exchanger 9. The heat medium oil heater 15 is connected to a pump (not shown) for circulating the heat medium oil. The pump circulates the heat medium oil between the heat exchanger 9, the reactor 10 and the heat medium oil heater 15.
[0026]
The hot water discharged from the reactor 10 is discharged from the discharge pipe 20 and cooled by the cooler 21, and then passes through the line filter 22, which is an average 5 μm stainless sintered filter, and is further discharged through the pressure holding valve 23. And recovered. Since the line filter 22 and the sintered filter 14 of the reactor 10 may cause clogging, pressurized hot water discharged from the heat exchanger 9 is allowed to flow from the line filter 22 side through the backflow cleaning line 24. Piping that eliminates clogging is placed.
[0027]
[Method for producing water-soluble saccharide]
Hereinafter, a preferred example of a production method for producing a water-soluble saccharide using the above-described production apparatus will be described. The raw material used in the method of the present invention includes plants containing hemicellulose, such as woody products such as conifers and hardwoods, agricultural waste such as rice husks and straws, kenaf and tea leaves (including extraction residues from which tea is extracted). Plants can be used. Although the shape of these raw materials is not particularly limited, it is preferably pulverized to the extent of passing through a 12-mesh sieve for efficient extraction. These raw materials do not need to be dried, and are put into the reactor 10 as they are after pulverization or as a slurry with water. The reactor 10 is capped at the inlet and outlet with the above-described sintered filter 14 so that the sample does not flow out.
[0028]
The saccharide is decomposed and extracted by passing pressurized hot water through the reactor 10 filled with the sample. The temperature at that time is in the range of 140 to 230 ° C., and the pressure at that time is the temperature at that time. It is necessary to contact the sample in a liquid state by being pressurized to a saturated water vapor pressure or higher, that is, 0.4 to 2.8 MPa or higher. If the pressurized hot water temperature is lower than 140 ° C., the decomposition of hemicellulose does not occur, and if it is higher than 230 ° C., the decomposition of cellulose begins and secondary decomposition of the obtained saccharide also occurs.
[0029]
If the pressure is equal to or lower than the saturated water vapor pressure at that time, the hot water comes into contact with the sample in the vapor state, so the thermal decomposition reaction is dominant over the hydrolysis reaction, and the product becomes a gas other than sugar or an aromatic component. Therefore, it is not preferable. The pressure does not need to be extremely high. In order to keep hot water in a stable liquid state, the pressure is maintained at 1.0 to 3.0 times, preferably 1.1 to 1.5 times the saturated water vapor pressure. Is preferred.
[0030]
The flow rate of the pressurized hot water is set so that the passage time in the hot water reactor 10 is usually 30 seconds or more and 15 minutes or less, preferably 2 minutes or more and 8 minutes or less. If it is less than 30 seconds, the content of low molecular sugar is small, and if it exceeds 15 minutes, secondary decomposition of the produced sugar proceeds. If the hydrothermal treatment time is continued until almost no solute in the effluent is observed, the yield is improved, but it is usually 15 to 30 minutes in practice considering the operation efficiency.
[0031]
It is desirable that the hot water flowing out of the reactor 10 is immediately cooled in order to suppress secondary decomposition of the water-soluble saccharide contained therein. Moreover, since the effluent obtained until the pressurized hot water temperature at the start of operation reaches 140 ° C. contains water-soluble components other than sugar, it is preferably removed. In addition, as a method for previously removing intracellular components other than sugars, pressurized hot water at normal temperature to less than 140 ° C, preferably 110 to 130 ° C, is circulated for 10 to 30 minutes, preferably 15 to 20 minutes. Is also effective for obtaining a highly pure water-soluble saccharide.
[0032]
If necessary, the aqueous solution obtained by the above method can be used as a purified water-soluble sugar solution by subjecting it to normal decolorization or desalting treatment with activated carbon or ion exchange resin. Further, it can be dried and used as a readily water-soluble powdered sugar.
[0033]
[Example 1]
Next, an embodiment of the present invention using the manufacturing apparatus described above will be specifically described in detail. The present invention is not limited in any way by these examples. About 100 g of pulverized kenaf core is charged into a 1.2 L stainless steel reaction vessel 10 and capped with a stainless sintered filter having a pore size of 20 microns, and then hot water whose temperature is controlled from the bottom of the reactor 10 is added. Water was passed at a pressure of 3 MPa and a flow rate of 300 cc / min using a high-pressure pump. The aqueous solution flowing out of the reactor 10 was cooled to 40 ° C. or lower by the cooler 21, and then led to the receiver under atmospheric pressure through the pressure holding valve 16.
[0034]
Flowing hot water at 120 ° C. for 20 minutes to remove components other than sugar (first fraction) and then flowing hot water at 200 ° C. for 25 minutes to obtain a hemicellulose degradation product (second fraction) from Dionex ( An ion chromatogram obtained using a sugar analyzer manufactured by USA was analyzed. Similarly, the ion chromatogram of the second fraction obtained by treatment with hot water at 180 ° C. for 25 minutes was analyzed . It was shown that the degradation extract obtained at any temperature consisted of a peak of xylose, a peak of 2-10 oligosaccharides bound to xylose, and a group of peaks observed on the longer side.
[0035]
The peak component around 45 to 50 minutes was confirmed to be a polysaccharide having xylose as a unit by sulfuric acid hydrolysis. As a result, it was confirmed that the water-soluble sugar in the second fraction of the kenaf core was a monosaccharide xylose, a xylooligosaccharide in which a plurality of xyloses were bonded, and a xylopolysaccharide.
[0036]
[Example 2]
As in Example 1, the pulverized kenaf core was used as a sample, and the first fraction was extracted and removed with hot water at 120 ° C. for 20 minutes at an operating pressure of 3.0 MPa, and then 167 ° C., 185 ° C., 193 ° C. Table 1 shows the yield of the second fraction and the composition of the second fraction when subjected to decomposition and extraction at 204 ° C. for 25 minutes.
[0037]
[Table 1]

Here, the amount from monosaccharide to pentasaccharide was determined by ion chromatographic analysis by a calibration curve method using a standard substance, and the amount of lignin was determined as the amount of 3% sulfuric acid insoluble in the second fraction. The amount of polysaccharide was determined as a value obtained by subtracting the amount from monosaccharide to pentasaccharide and the amount of lignin from the second fraction amount. It was shown that the ratio of the high molecular weight polysaccharide increases as the pressurized hot water temperature decreases, but the ratio of the mixed lignin decreases. As described above, this method has a high ratio of components corresponding to water-soluble dietary fiber. The higher the hot water temperature is, the higher the yield of the second fraction is. This is because lignin is further decomposed, and as a result, the low molecular weight lignin flows out together with the saccharide.
[0038]
[Example 3]
Using kenaf, rice straw, wheat straw, and rice husk as samples, the first fraction was extracted and removed at 120 ° C for 20 minutes at an operating pressure of 3.0 MPa, and then the second fraction was decomposed and extracted for 25 minutes at around 198 ° C. went. Table 2 shows the yield of the second fraction and the concentrations of monosaccharide to pentasaccharide (mono-5 sugar) in the second fraction.
[0039]
[Table 2]

In the case of rice straw, wheat straw and rice husk, arabinose was also obtained as a sugar component. In the case of kenaf and straw, the yield of the second fraction is as high as 40%, but the ratio of monosaccharide-5 sugar is relatively low at 10-15%, whereas in rice husk, the second fraction yield is high. Was as low as 32%, but the ratio of monosaccharide-5 sugar was about 25%, which was very high.
[0040]
【Effect of the invention】
The method for producing a water-soluble saccharide according to the present invention is a method using a water-soluble saccharide containing a hemicellulose, a dietary fiber useful as a health food, an oligosaccharide, and a monosaccharide in a well-balanced manner using only pressurized hot water. It can be manufactured efficiently.
[Brief description of the drawings]
FIG. 1 shows an outline of a water-soluble saccharide production apparatus and is a flow diagram of hot water.

Claims (1)

In the method for producing a water-soluble saccharide produced from a plant containing hemicellulose,
To the plant, a soluble substance other than sugar in the plant is washed away with pressurized hot water having a temperature of room temperature to less than 140 ° C. and a pressure of 3 MPa for 20 minutes,
By contacting the plant from which soluble substances other than sugar in the plant have been washed away with pressurized hot water at a temperature of 140 to 230 ° C. and a pressure of 3 MPa for 25 minutes to hydrolyze the plant containing the hemicellulose. A method for producing a water-soluble saccharide, wherein a water-soluble lignin having radical scavenging ability, a water-soluble saccharide comprising a monosaccharide and an oligosaccharide and a polysaccharide which is a category of dietary fiber are extracted.

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