CN115948623A

CN115948623A - Preparation method of maltose crystal

Info

Publication number: CN115948623A
Application number: CN202310072138.1A
Authority: CN
Inventors: 黄伟红; 孙鲁; 贺东海; 方春雷; 曹玉华; 杜瑞锋; 史晓委; 刘杰; 邵杰
Original assignee: Shandong Futaste Pharmaceutical Co ltd
Current assignee: Shandong Futaste Pharmaceutical Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2023-04-11
Also published as: CN114369689A

Abstract

The invention belongs to the technical field of sugar alcohol production, and particularly relates to a preparation method of maltose crystals. The invention provides a preparation method of maltose crystals, which adopts a water system cooling crystallization method to prepare the maltose crystals: preparing maltose syrup from starch through size mixing, liquefying and saccharifying, performing chromatographic separation to obtain high-purity maltose syrup, and performing concentration and crystallization to prepare high-purity maltose crystals which are obtuse triangular flaky crystals; finally obtaining maltose crystals with higher purity and stable quality.

Description

Preparation method of maltose crystal

The application is a divisional application of invention patent with application date of 2021, 12 and 31, application number of 202111671556.X, title of "a crystalline maltose and its preparation method".

Technical Field

The invention belongs to the technical field of sugar alcohol production, and particularly relates to a preparation method of maltose crystals.

Background

Maltose is a nutritive disaccharide produced by enzymolysis of starch and other raw materials, and is widely applied to the fields of food and medicine. Maltose is formed by connecting 2 molecules of glucose through alpha-1,4 glycosidic bonds. The alpha-type and beta-type isomers are different due to the position of the hydroxyl group of C1. The common food grade maltitol powder product is a mixture of two configurations and also contains partial dextrin or oligosaccharide impurities. The maltose product belongs to starch sugar which is difficult to crystallize, and dextrin and oligosaccharide exist, so that the maltose syrup is sticky, the higher the concentration is, the higher the viscosity is, crystals are difficult to separate out, and even crystal particles are generated, the separation is difficult. The commercial maltose solid product is generally prepared by directly dehydrating high-purity maltose syrup, and the crystal particles are irregular or approximately spherical and are opaque. The mass percentage content of maltose is about 90% generally, and the purity of the product can reach about 95%. The existence of impurities, particularly maltotriose, in the powder product affects the stability of the powder product, and the powder product is easy to absorb moisture and agglomerate in the air, so that the powder product brings inconvenience to production and use. Therefore, many manufacturers directly sell the liquid maltose syrup product, which is not easy to store for a long time and transport over long distance, and has a certain limitation in market circulation.

Some researchers and others crystallized maltose using alcohol. The invention patent CN110938715 discloses a maltose crystallization process, wherein 85% of maltose syrup by mass percent is subjected to membrane filtration, decolorization, ion exchange treatment and vacuum crystallization after concentration, anhydrous alcohol with the mass of 30% -50% of the syrup is required to be added in the crystallization process, the alcohol belongs to volatile substances, the requirements on the sealing property of production equipment, the safety of a production workshop, the operation accuracy of personnel and the like are high in industrial production, and the production process is complicated.

The invention patent CN107447058 discloses a preparation method of crystalline maltose, the process adopts alcohol to dissolve seed crystals, the usage amount of alcohol in the whole crystallization process is 3.7% -34.8%, the usage amount of alcohol changes along with the change of the addition amount of the seed crystals, the usage amount of the seed crystals used by maltose raw materials with different qualities is possibly different, the usage amount of the alcohol also changes greatly, the requirements on equipment and personnel in industrial production are high, and potential safety hazards exist.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method of maltose crystals. The crystal grains of the obtained high-purity maltose crystal product with stable quality are blunt triangular flaky crystals.

In order to achieve the purpose of the invention, the technical scheme of the invention is as follows:

the invention provides a preparation method of maltose crystals, wherein the maltose crystals are blunt triangular flaky crystals; the method specifically comprises the following steps:

(1) Size mixing

Mixing starch with deionized water to prepare starch milk with the mass percentage concentration of 25% -30%, adjusting the pH to 5.5-6.0 by using sodium carbonate, adding calcium chloride and high-temperature resistant alpha-amylase, and uniformly stirring;

(2) Liquefaction

Introducing steam into the adjusted starch milk to raise the temperature, and controlling the liquefaction temperature and the liquefaction time by utilizing primary injection and secondary injection to obtain liquefied liquid; the liquefaction temperature is 96-110 ℃, the liquefaction time is 30-60min, and the DE value of the liquefied liquid is 15% -25%;

(3) Saccharification

Cooling the liquefied solution to 55-60 ℃, adjusting the pH value to 4.0-5.0 by using sodium carbonate, and adding a glucose-starch complex enzyme for saccharification to obtain a saccharified solution; the saccharification temperature is 58-60 ℃, the saccharification time is 40-70 hours, and the addition amount of the glucose-starch complex enzyme is 0.5-0.9kg/t dry matter; the content of glucose in the saccharification liquid is less than 5%;

(4) Purifying and concentrating

Adding 0.05-2% of active carbon in dry amount into the saccharified liquid, keeping the temperature at 70-80 ℃ for 20-30min, and filtering and separating the active carbon to obtain a decolorized liquid; performing ion exchange on the decolorized solution to obtain a purified solution; concentrating the purified solution by using a multi-effect evaporator at 75-85 ℃ to 40-50% of mass percent for later use;

(5) Chromatographic separation

The chromatographic separation conditions are as follows: the temperature is 70-75 ℃, the feeding concentration is 40-50%, and the content of maltotriose in the obtained maltose syrup is less than 1.5%;

(6) Concentrating and crystallizing

Further concentrating the maltose syrup fraction collected by chromatographic separation to obtain massecuite; controlling the initial temperature of the massecuite to be 65-75 ℃ and the initial concentration of the massecuite to be 65-72%, adopting a programmed cooling, wherein the initial cooling speed is 1 ℃/h, adding crystal seeds when the temperature is reduced to 58-63 ℃, then preserving heat for 1-2 h for growing crystals, and slowly cooling after the crystal grains are formed, wherein the slow cooling speed is 0.5 ℃/h-2 ℃/h; cooling to room temperature, performing centrifugal separation, adding deionized water with the mass accounting for 3-10% of that of the massecuite in the separation process, rinsing, and centrifuging to obtain the maltose crystal.

Preferably, the addition amount of the calcium chloride in the size mixing in the step (1) is 0.2-0.6g/kg of dry matter, and the addition amount of the high-temperature resistant alpha-amylase is 0.5-1.2kg/t of dry matter.

Preferably, the resins used for ion exchange in the step (4) are 001 × 7 and D301 resins, and the ion exchange process is anion-cation-anion-cation; the active carbon used for decoloring is powdered active carbon for sugar, and the active carbon is filtered to obtain a decoloring solution.

Preferably, the chromatographic separation resin used in the step (5) is a potassium cation chromatographic separation resin.

Preferably, in the step (6), the seed crystal is maltose micropowder, and the amount of the seed crystal added is 0.02-0.5% of the dry mass of the massecuite; vacuum low-temperature concentration is adopted for concentration; the maltose micropowder used for the seed crystal has the particle size distribution of more than 90 percent in 100-200 meshes, the mass percent content of maltose of more than 95 percent and the water content of less than 0.1 percent.

The scheme provided by the invention has the following technical effects:

by controlling the starch liquefying and saccharifying processes, the content of glucose in the obtained decolored and purified solution is less than 5%, and the content of maltotriose is less than 1%, so that good conditions are provided for subsequent purity improvement and stable product quality.

In the chromatographic separation step, the impurities above maltotriose are reduced to below 1.5 percent by controlling the chromatographic separation condition of the maltose syrup. Controlling the content of maltotriose can reduce the viscosity of maltose syrup and is beneficial to the growth of maltose crystal grains.

The invention adopts low-concentration crystallization, the concentration of massecuite is 65-72%, the initial crystallization temperature is 65-75 ℃, and the temperature is reduced to 58-63 ℃ and seed crystal is added. The low-concentration crystallization reduces the viscosity of the sugar solution, reduces the probability of forming bond bridges among maltose molecules, and is beneficial to the growth of maltose crystal grains.

The method adopts water system crystallization, avoids the use of organic solvents such as alcohol and the like, does not need solvent recovery, improves the adaptability of industrial production, and has convenient operation and environmental protection.

The maltose crystal obtained by the invention is an obtuse triangular flaky crystal, and the obtained product has high purity, stable property, no moisture absorption, easy storage, no easy deterioration and long quality guarantee period; the conventional directly dried irregular granular crystal product is easy to absorb moisture and sticky, has high requirements on storage conditions, and needs to be used as soon as possible after being packaged and unsealed.

Through the combination of the key technical means, the content of impurities such as maltotriose and the like is obviously reduced, and finally the high-purity crystal maltose product suitable for industrial production and use is obtained.

Drawings

FIG. 1 is a microphotograph of maltose crystals obtained in examples 1 and 2 of the present invention;

FIG. 2 is a crystallization peak spectrum of maltose crystals obtained in example 1;

FIG. 3 is a photomicrograph of a maltose crystal obtained from the saccharified solution of example 3 having a glucose content of 7.88%;

FIG. 4 is a crystal photomicrograph of maltose under other conditions as a comparison in tables 4 and 5, in which the maltotriose content is 3.44% at the upper left, the massecuite initial concentration is 76% at the lower left, the maltotriose content is 2.01% at the upper right, and the massecuite initial concentration is 74% at the lower right.

Detailed Description

The present invention will be further described with reference to specific examples so that those skilled in the art may better understand the present invention, but the present invention is not limited thereto.

Example 1

(1) Size mixing

Mixing starch and deionized water to prepare starch milk with the mass percentage concentration of 26%, adjusting the pH to 5.5 by using sodium carbonate, adding calcium chloride and high-temperature-resistant alpha-amylase, wherein the adding amount of the calcium chloride is 0.4g/kg of dry matter, and the adding amount of the alpha-amylase is 0.8kg/t of dry matter, and uniformly stirring.

(2) Liquefaction

Introducing steam into the adjusted starch milk, heating, controlling the liquefaction temperature to 97-105 ℃ by utilizing primary injection and secondary injection, and liquefying for 30min to obtain liquefied liquid.

(3) Saccharification

Cooling the liquefied solution to 60 deg.C, adjusting pH to 4.5 with sodium carbonate, and adding glucose-starch complex enzyme for saccharification. The saccharification temperature is 60 ℃, the saccharification time is 48 hours, and the addition amount of the glucose-starch complex enzyme is 0.6kg/t dry matter.

(4) Purifying and concentrating

Adding powdered activated carbon for sugar 0.5% of the dry weight of the saccharified solution, keeping the temperature at 75-80 deg.C for 20min, and filtering to separate the activated carbon to obtain decolorized solution. And (4) performing anion-cation-anion-cation exchange on the decolorized solution to obtain a purified solution. Indexes of the purified liquid: the content of maltose (dry matter percentage content) is 89.0%, glucose is 4.7%, maltotriose is 0.75%, maltotetraose is 4.5%, and other components are about 1%.

Concentrating by using a multi-effect evaporator at 75-80 ℃ to 45% by mass for later use.

(5) Chromatographic separation

The temperature was 70 ℃, the feed concentration was 45%, and the feed flow rate was 3L/h. The resin was chromatographed using potassium. Index of maltose syrup after chromatography: maltose content 95.4%, glucose 3.9%, and others about 0.7%.

(6) Concentrating and crystallizing

Concentrating the collected maltose syrup by the chromatographic separation in the step (5) under the conditions of 75 ℃ and vacuum-0.94 Mpa until the mass percentage concentration is 71.4%, transferring the maltose syrup into a crystallizer preheated to 70 ℃, uniformly stirring, controlling the initial temperature of the massecuite to be 70 ℃, cooling at the speed of 1 ℃/h, controlling the temperature precision to be +/-0.5 ℃, adding seed crystals when the temperature is reduced to 61 ℃, keeping the temperature for 2h for crystal growing, entering a cooling program when the suspension density of crystal grains reaches 5-10%, cooling to 25 ℃ at the speed of 0.5 ℃/h, separating by adopting a high-speed centrifuge, separating the maltose syrup by a separation factor 1050, quickly leaching in the centrifugal process, washing with deionized water with the amount of 10% of the massecuite, and centrifugally separating maltose crystals and mother liquor at the temperature of 25 ℃.

According to the maltose crystallization peak in FIG. 2, the corresponding ratio of each substance (as shown in Table 1) is obtained, and the maltose purity is 98.719%; the content of impurities such as maltotriose and the like is obviously reduced.

TABLE 1 maltose crystallization peak respective substance corresponding ratio

Number of peak	Name of Compound	Retention time	Proportion (area%)
				1	Polysaccharides	6.286	0.018
2	Maltotetraose	8.148	0.053
				3	Maltotriose	8.699	0.161
4	Maltose	9.749	98.719
				5	Glucose	11.509	1.050
In total			100.000

Example 2

(1) Size mixing

Mixing starch and deionized water to prepare starch milk with the mass percentage concentration of 28%, adjusting the pH to 6.0 by using sodium carbonate, adding calcium chloride and high-temperature-resistant alpha-amylase, wherein the adding amount of the calcium chloride is 0.4g/kg of dry matter, and the adding amount of the alpha-amylase is 0.8kg/t of dry matter, and uniformly stirring.

(2) Liquefaction

Introducing steam into the adjusted starch milk, heating, controlling the liquefaction temperature to 97-105 ℃ by using primary injection and secondary injection, and liquefying for 30min to obtain liquefied liquid.

(3) Saccharification

(4) Purifying and concentrating

The concentration adopts a multi-effect evaporator, and the concentration is carried out at 75-80 ℃ until the mass percentage concentration is 45% for standby.

(5) Chromatographic separation

The temperature is 70 ℃, the feeding concentration is 45 percent, and the feeding flow rate is 3L/h. The resin was chromatographed using potassium. Index of maltose syrup after chromatographic separation: maltose content 95.4%, glucose 3.9%, and others about 0.7%.

(6) Concentrating and crystallizing

Using the same test procedure as in example 1 (as shown in Table 2), the final maltose purity is 99.72%, and its maltotriose and other impurities content is significantly reduced.

TABLE 2 maltose crystallization peak substance corresponding ratio

Peak number	Name of Compound	Retention time	Proportion (area%)
				1	Polysaccharides	6.286	0.002
2	Maltotetraose	8.146	0.013
				3	Maltotriose	8.699	0.043
4	Maltose	9.749	99.720
				5	Glucose	11.510	0.222
Total of			100.000

Example 3

Starch liquefaction is carried out according to the steps (1) and (2) of the invention, and A, B, C saccharified liquids are obtained by controlling the saccharification conditions, wherein the contents of glucose are respectively A:5.00%, B:5.92%, C:7.88 percent.

According to the steps (4) and (5) of the invention, the saccharification liquid is purified, concentrated and separated by chromatography, and the content of maltotriose is controlled, wherein A:1.49%, B:1.43%, C:1.46 percent.

A. B, C three maltose liquids are concentrated and crystallized under the same process conditions according to the step (6) of the invention, and after centrifugal separation, the maltose content is detected and microscopic crystal forms are observed. The results are shown in Table (3):

TABLE 3 influence of different glucose contents in the saccharification liquors on the crystalline form of maltose crystals

Content of glucose%	Maltotriose content%	Maltose Crystal content%	Crystalline form of maltose
				5.00	1.49	98.72	Obtuse triangle, slightly stacked
5.92	1.43	96.13	Obtuse triangle with a stack
				7.88	1.46	93.34	Crystal sheet irregularity

Example 3 is a reverse example of the present invention, where different glucose contents in the mash have an effect on the maltose crystal type, the glucose content is higher than 5%, and the maltose crystal type changes, as shown in fig. 3.

Example 4

Starch liquefaction is carried out according to the steps (1) and (2) of the invention, and A, B, C saccharified liquids are obtained by controlling the saccharification conditions, wherein the contents of glucose are respectively A:5.00%, B:4.93%, C:5.06 percent.

According to the steps (4) and (5) of the invention, the saccharified liquid is purified, concentrated and separated by chromatography, and the content of maltotriose is controlled, wherein A:1.49%, B:2.01%, C:3.44 percent.

A. B, C three maltose liquids are concentrated and crystallized under the same process conditions according to the step (6) of the invention, and after centrifugal separation, the maltose content is detected and microscopic crystal forms are observed. The results are shown in Table (4):

TABLE 4 influence of different maltotriose contents in the mash on the maltose modification

Maltotriose content%	Glucose content%	Maltose Crystal content%	Crystalline form of maltose
				1.49	5.00	98.72	Obtuse triangle, slightly stacked
2.01	4.93	92.06	Irregular flake shape with lumps
				3.44	5.06	89.25	Irregular spherical shape with lumps

Example 4 is a reverse example of the present invention, and the content of maltotriose in the saccharified liquid after chromatographic separation has an influence on the crystallization process and the crystal form of maltose. Therefore, the content of maltotriose is controlled to be less than 1.5 percent, and relatively good blunt triangular flaky crystals can be obtained.

Example 5

Preparing maltose liquid according to the steps (1) to (5) of the invention, crystallizing according to the step (6) of the invention, controlling different massecuite initial concentrations, recording the centrifugal separation process, calculating the centrifugal yield (the percentage of the crystal mass to the massecuite mass), and observing the microscopic crystal form. The results are shown in Table 5:

TABLE 5 relationship between initial concentration of massecuite and crystal yield and crystal form

Initial concentration of massecuite	Centrifugal process	Centrifugal yield%	Crystal form
				76％	Difficult water washing separation	42.91	Irregular flake shape with lumps
74％	Can be separated by water washing	53.63	Dull triangular sheet with lumps
				72％	Can be separated by water washing	53.99	Obtuse triangular sheet
68％	Can be separated by water washing	54.28	Obtuse triangular sheet
				65％	Can be separated by washing	52.86	Obtuse triangular sheet
63％	Can be separated by water washing	48.96	Obtuse triangular sheet

Example 5 is a comparative example of the present invention, where different initial massecuite concentrations in the crystallization process have an effect on the formation of the maltose crystal form. The concentration of the massecuite is too high, so that the massecuite is not beneficial to the growth of crystal grains and is easy to form agglomeration; lower concentrations affect the yield.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.

Claims

1. A preparation method of maltose crystal is characterized in that the maltose crystal is blunt triangular flaky crystal; the method specifically comprises the following steps:

(1) Size mixing

(2) Liquefaction

(3) Saccharification

(4) Purifying and concentrating

Adding active carbon accounting for 0.05-2% of the dry weight of the saccharification liquid, preserving the heat for 20-30min at 70-80 ℃, and filtering and separating the active carbon to obtain decolorized liquid; performing ion exchange on the decolorized solution to obtain a purified solution; concentrating the purified solution by using a multi-effect evaporator at 75-85 ℃ to a mass percent concentration of 40% -50% for later use;

(5) Chromatographic separation

(6) Concentrating and crystallizing

Further concentrating the maltose syrup fraction collected by chromatographic separation to obtain massecuite; controlling the initial temperature of the massecuite to be 65-75 ℃ and the initial concentration of the massecuite to be 65-72%, adopting a programmed cooling, wherein the initial cooling speed is 1 ℃/h, adding crystal seeds when the temperature is reduced to 58-63 ℃, then preserving heat for 1-2 h for growing crystals, and slowly cooling after the crystal grains are formed, wherein the slow cooling speed is 0.5 ℃/h-2 ℃/h; cooling to room temperature for centrifugal separation, adding deionized water with the mass of 3-10% of that of the massecuite in the separation process for leaching, and centrifuging to obtain the maltose crystal.

2. The preparation method of claim 1, wherein the addition amount of calcium chloride in the size mixing in the step (1) is 0.2-0.6g/kg of dry matter, and the addition amount of the high temperature resistant alpha-amylase is 0.5-1.2kg/t of dry matter.

3. The method according to claim 1, wherein the resins used for the ion exchange in step (4) are 001 x 7 and D301 resins, and the ion exchange process is anion-cation-anion-cation; the active carbon used for decoloring is powdered active carbon for sugar, and the active carbon is filtered to obtain decolored liquid.

4. The method according to claim 1, wherein the chromatographic resin used in the step (5) is a potassium type cationic chromatographic resin.

5. The preparation method according to claim 1, wherein in the step (6), the seed crystal is maltose micropowder, and the amount of the seed crystal added is 0.02-0.5% of the dry mass of the massecuite; concentrating at low temperature; the maltose micropowder used for the seed crystal has the granularity distribution of 100-200 meshes accounting for more than 90 percent, the mass percentage content of maltose accounting for more than 95 percent and the water content accounting for less than 0.1 percent.