Production process of high-purity malt syrup

Abstract

The invention discloses a production process of high-purity malt syrup, which comprises the following steps: S1, starch is subjected to size mixing and liquefaction, and the DE value of liquefaction is controlled at 1-2%; s2, controlling the temperature of the liquefied liquid to 55-60 DEG C, controlling the pH value to 4.2-7.2, and adding debranching enzyme and beta amylase for saccharification treatment; s3, after saccharification is completed, ethanol is added until the concentration is 20%, the reaction continues for 2 h, the ethanol concentration is increased to 40%, and the reaction continues for 2 h; s4, cooling to 30-35 DEG C, adding ethanol until the concentration is 80%, carrying out enzyme deactivation, and standing for crystallization; and S5, centrifugally separating the crystal substance, and drying to obtain the maltose. Through the design of multienzyme synergy, step-by-step enzymolysis, ethanol denaturation and the like, the purity and the yield of the maltose product are greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of maltose production, and particularly relates to a production process of high-purity maltose syrup. BACKGROUND

[0002] Maltose is a natural disaccharide formed by two glucose molecules, which can be absorbed in the human body without the participation of insulin metabolism, and is particularly suitable for diabetic patients to supplement nutrition. Maltose syrup is a kind of syrup mainly containing maltose, which is prepared by using starch as raw material, enzymatic or acid-enzyme hydrolysis, and then refining and concentrating. According to the content of maltose in the maltose syrup, the maltose syrup can be divided into ordinary maltose syrup, high-maltose syrup and super-high-maltose syrup. The maltose syrup with a maltose content of less than 60% is ordinary maltose syrup, the maltose syrup with a maltose content of 60-70% is high-maltose syrup, and the maltose syrup with a maltose content of more than 70% is super-high-maltose syrup.

[0003] At present, the reason for the low synthesis yield of maltose syrup is that a large amount of maltotriose, maltotetraose and various oligosaccharides are produced at the end of starch enzymatic synthesis, which cannot be effectively converted into maltose. Patent CN 109371078 A discloses a preparation process of high-purity maltose. By using pullulanase and maltotetraose amylase for saccharification of the liquefied liquid, the maltodextrin content in the liquefied liquid is reduced, the beta-amylase can better act on the liquefied liquid, the maltotriose content is reduced by maltose amylase, and the glucose content is reduced by adding yeast, so that the purity of maltose can be increased by 3-4 percentage points. However, the enzymatic process is affected by the product concentration, and high concentration of maltose can inhibit the ability of maltotetraose to be converted into maltose, and the overall conversion efficiency is not high. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a production process of high-purity maltose syrup. By introducing ethanol at the end of oligosaccharide conversion maltose saccharification, the enzymatic process continues to move to the right, thereby improving the conversion rate of maltose.

[0005] The purpose of the present application is achieved by the following technical scheme: a production process of high-purity maltose syrup, comprising the following steps, S1. The starch is slurried and liquefied, and the DE value of the liquefied starch is controlled at 1-2%; S2. The liquefied liquid is controlled to 55-60 DEG C, the pH value is controlled at 4.2-7.2, and the debranching enzyme and beta-amylase are added for saccharification treatment; S3. After saccharification, ethanol is added to 20% concentration for 2h, and the ethanol concentration is increased to 40% for 2h; S4. The temperature is reduced to 30-35 DEG C, ethanol is added to 80% concentration for enzyme inactivation and crystallization; S5. Centrifugal separation of the crystalline substance, drying, and maltose is obtained.

[0006] Preferably, in step S1, the mass percentage of starch slurry is 5-10%, the pH value is adjusted to 5.8-6.2, and the liquefaction temperature is 105-115℃.

[0007] Preferably, in step S1, a high-temperature-resistant alpha amylase is added during liquefaction, and the enzyme dosage is 0.5-0.8 kg / t ds starch slurry.

[0008] Preferably, in step S2, a pullulanase is first added for preliminary saccharification, after saccharification is completed, the temperature is raised to 60-65℃, the pH value is controlled at 6.0-7.2, a maltulose-forming enzyme is added for saccharification to generate a substrate, and then a beta amylase is added for sufficient saccharification.

[0009] Preferably, the enzyme dosage of the pullulanase is 8-10 kg / t ds liquefied liquid, and the saccharification treatment time is 2 h.

[0010] Preferably, the enzyme dosage of the maltulose-forming enzyme is 14-25 kg / t ds liquefied liquid.

[0011] Preferably, the enzyme dosage of the beta amylase is 2-3 kg / t ds liquefied liquid, and the beta amylase is added when the maltulose concentration in the liquefied liquid is 50%.

[0012] Preferably, in step S3, the ethanol is initially added to the liquefied liquid when the maltulose content is ≥ 85% and the growth rate is < 0.5%.

[0013] Preferably, in step S5, the mother liquor after separation contains a large amount of glucose and ethanol, which can be introduced into an ethanol distillation column to recover the ethanol, the remaining sugar solution is collected and impurities are removed using activated carbon, and finally a simulated moving bed is introduced for chromatographic separation to separate the sugar.

[0014] The present application has the following advantages: 1. By strictly controlling the DE value of liquefaction, the problem of a large amount of glucose caused by the random cutting of starch chains by alpha amylase is reduced, the proportion of glucose in maltulose is reduced, and the product purity is improved; 2. By the action of debunching enzyme, maltulose-forming enzyme, and beta amylase on liquefied starch in sequence, amylopectin is converted into short-chain amylose, amylose is converted into oligomeric maltulose, and finally maltulose is converted into maltulose, step-by-step action makes the conversion of starch to maltulose more complete, maltulose-forming enzyme can quickly convert long-chain amylose with a molecular weight of 100 million into maltulose, which can shorten the time by 0.5 times compared with maltotetraose-forming enzyme, and improve the overall production efficiency; 3. By adding ethanol in a gradient to the liquefaction liquid at the end of maltose hydrolysis, the protease does not become inactive under low concentrations of ethanol and still maintains its hydrolytic function. At the same time, ethanol disrupts the hydrolytic equilibrium, causing the hydrolysis process to continue to the right, thereby increasing the conversion rate of maltose and reducing the proportion of by-products. High concentrations of ethanol can not only directly inactivate the protease, but also cause maltose to crystallize and precipitate in ethanol. Compared with crystallization in water, the product purity is higher. 4. A process for the enzymatic hydrolysis of maltose syrup is provided, which simultaneously improves the purity and yield of maltose products through multi-enzyme synergy, stepwise enzymatic hydrolysis, and ethanol denaturation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0017] Example 1 like Figure 1 As shown, high-purity maltose syrup is prepared according to the following steps. S1. Starch liquefaction: Corn starch is added to water to prepare a starch slurry with a mass concentration of 5%. The pH of the solution is adjusted to 5.8 using 10% hydrochloric acid under stirring. α-high-temperature amylase is added at a rate of 0.5 kg / tds starch slurry. After stirring evenly, continuous spray liquefaction is performed, controlling the temperature at 115℃ to achieve a DE value of 1% for the liquefied solution. S2. Debranching treatment: Cool the liquefied liquid to 50℃, adjust the pH to 4.2 with hydrochloric acid, accurately weigh pullulanase debranching enzyme, add enzyme amount of 10kg / tds liquefied liquid, and keep warm for saccharification treatment for 2h to decompose amylopectin into linear chains. S3. Maltohexasaccharide hydrolysis: After saccharification, sodium carbonate solution is added to adjust the pH to 7.2 and the temperature to 60℃. Maltohexasaccharide generating enzyme is added at a rate of 14 kg / tds liquefaction liquid. The reaction is carried out under controlled temperature to generate some maltohexasaccharide as a substrate for β-amylase. S4. β-amylase hydrolysis was performed, and the concentration of maltohexaose in the liquefaction solution was checked every 2 hours. After 6 hours, it reached 54.5%. β-amylase was then added at a rate of 2 kg / tds of liquefaction solution to decompose maltohexaose into maltose under the action of β-amylase. S5. Add ethanol once, and check the maltose concentration in the liquefied liquid every 2 hours. After 4 hours, when the maltose content is ≥85% and the increase is <0.5%, add 95% ethanol. Add the ethanol slowly dropwise while stirring, keep the temperature stable, and keep warm for 2 hours after the addition is complete. S6. Second ethanol addition, continue to add ethanol to 40% concentration, keep for 2h; S7. Enzyme-killing crystallization, quickly add ethanol and increase the concentration to 80%, make the enzymes completely inactive, stop stirring, slowly reduce the temperature to 25℃, make the maltose crystallize for 2h; S8. Centrifugal separation of maltose crystals, put into the dryer under the condition of 60℃, dry, get high-purity maltose, use chromatograph to detect the purity, the purity reaches 96.4%, the calculated crystallization yield reaches 80.8%.

[0018] Example 2 High-purity maltose syrup, prepared according to the following steps, S1. Starch liquefaction, add corn starch into water to prepare starch slurry with a mass concentration of 7%, use 10% hydrochloric acid to adjust the pH value of the solution to 6.2 under stirring, add alpha high-temperature amylase, the addition amount is 0.7kg / t ds starch slurry, stir uniformly, then perform continuous jet liquefaction, control the temperature to be 115℃, and make the DE value of the liquefied liquid to be 1%; S2. Debranching treatment, reduce the temperature of the liquefied liquid to 60℃, use hydrochloric acid to adjust the pH value to 4.5, accurately weigh the pullulanase debranching enzyme, the enzyme addition amount is 10kg / t ds liquefied liquid, keep for 2h for saccharification treatment; S3. Maltotriose enzymolysis, after saccharification is completed, add sodium carbonate solution to adjust the pH value to 7.1, adjust the temperature to 65℃, add maltotriose generating enzyme, the enzyme addition amount is 20kg / t ds liquefied liquid, control the temperature to generate part of maltotriose as the substrate of beta amylase; S4. Beta amylase, during the period, detect the concentration of maltotriose in the liquefied liquid every 2h, after 6h, the concentration reaches 58.2%, add beta amylase, the enzyme addition amount is 2.5kg / t ds liquefied liquid; S5. First ethanol addition, during the period, detect the concentration of maltose in the liquefied liquid every 2h, after 4h, when the maltose content is ≥85% and the growth rate is <0.5%, add 95% ethanol, slowly drop the ethanol into the liquefied liquid and stir, keep the temperature stable, after the drop is completed, keep for 2h; S6. Second ethanol addition, continue to add ethanol to 40% concentration, keep for 2h; S7. Enzyme-killing crystallization, quickly add ethanol and increase the concentration to 80%, make the enzymes completely inactive, stop stirring, slowly reduce the temperature to 25℃, make the maltose crystallize for 2h; S8. Centrifugal separation of maltose crystals, put into the dryer under the condition of 60℃, dry, get high-purity maltose, use chromatograph to detect the purity, the purity reaches 95.8%, the calculated crystallization yield reaches 80.2%.

[0019] Example 3 High-purity maltose syrup was prepared according to the following steps, S1. Starch liquefaction, corn starch was added to water to prepare a starch slurry with a mass concentration of 10%, the solution was adjusted to a pH value of 6.0 under stirring using 10% hydrochloric acid, and alpha high-temperature amylase was added in an amount of 0.8 kg / t ds starch slurry. After uniform stirring, continuous jet liquefaction was performed, and the temperature was controlled at 105°C to make the DE value of the liquefied liquid 2%; S2. Debranching treatment, the liquefied liquid was cooled to 56°C, the pH value was adjusted to 5.5 using hydrochloric acid, and the debranching enzyme pululanase was accurately weighed and added in an amount of 8 kg / t ds liquefied liquid, and the temperature was maintained for 2 h for saccharification treatment; S3. Maltotriose enzymolysis, after saccharification was completed, sodium carbonate solution was added to adjust the pH value to 6.0, the temperature was adjusted to 65°C, and maltotriose generating enzyme was added in an amount of 25 kg / t ds liquefied liquid, and temperature control reaction was performed to generate part of maltotriose as the substrate of beta amylase; S4. Beta amylase, the concentration of maltotriose in the liquefied liquid was detected every 2 h during the period, and after 6 h, the concentration reached 51.4%. Beta amylase was added in an amount of 3 kg / t ds liquefied liquid; S5. First ethanol addition, the concentration of maltose in the liquefied liquid was detected every 2 h during the period, and after 4 h, when the maltose content was ≥85% and the growth rate was <0.5%, 95% ethanol was added. The ethanol was slowly added and stirred into the liquefied liquid, and the temperature was maintained stable. After the addition was completed, the temperature was maintained for 2 h; S6. Second ethanol addition, continue to add ethanol until the concentration reaches 40%, and maintain the temperature for 2 h; S7. Enzyme inactivation and crystallization, quickly add ethanol and increase the concentration to 80% to inactivate all enzymes, stop stirring, slowly reduce the temperature to 25°C, and make the maltose crystallize for 2 h; S8. Centrifugal separation of maltose crystals, put into a dryer at 60°C for drying, and high-purity maltose is obtained. The purity is detected using a chromatograph, and the purity reaches 94.1%. The crystallization yield reaches 78.6%.

[0020] Comparative Example 1 High-purity maltose syrup was prepared according to the following steps, S1. Starch liquefaction, corn starch was added to water to prepare a starch slurry with a mass concentration of 5%, the solution was adjusted to a pH value of 5.9 under stirring using 10% hydrochloric acid, and alpha high-temperature amylase was added in an amount of 0.5 kg / t ds starch slurry. After uniform stirring, continuous jet liquefaction was performed, and the temperature was controlled at 115°C to make the DE value of the liquefied liquid 1%; S2. Debranching treatment, the liquefied liquid is cooled to 60℃, hydrochloric acid is used to adjust the pH value to 4.2, the pullulanase debranching enzyme is accurately weighed, the enzyme amount is 10 kg / tds liquefied liquid, and the temperature is kept for 2 h for saccharification treatment; S3. Maltotetraose enzymolysis, after saccharification is completed, sodium carbonate solution is added to adjust the pH value to 5.3, the temperature is adjusted to 55℃, maltotetraose enzyme is added, the enzyme amount is 20 kg / tds liquefied liquid, and temperature control is performed to generate maltotetraose; S4. β Amylase hydrolysis, the concentration of maltotetraose in the liquefied liquid is detected every 1 h during the period, reaches 51.6% after 7.5 h, β amylase is added, and the enzyme amount is 2 kg / tds liquefied liquid; S5. First ethanol addition, the concentration of maltose in the liquefied liquid is detected every 1 h during the period, 95% ethanol is added after 4 h when the maltose content is ≥85% and the growth rate is <0.5%, the ethanol is slowly added and stirred into the liquefied liquid, the temperature is kept stable, and 2 h is kept after the addition is completed; S6. Second ethanol addition, the ethanol is continuously added until the concentration is 40%, and 2 h is kept; S7. Enzyme inactivation and crystallization, the ethanol is quickly added and the concentration is increased to 80% to inactivate all the enzymes, the stirring is stopped, the temperature is slowly reduced to 25℃, and the maltose is crystallized for 2 h; S8. The maltose crystals are separated by centrifugation, dried in a dryer at 60℃, and high-purity maltose is obtained, the purity is detected by using a chromatograph, the purity reaches 93.2%, and the crystallization yield reaches 77.8%.

[0021] Although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A production process for high-purity maltose syrup, characterized in that, Includes the following steps, S1. The starch is slurried and liquefied, with the DE value of liquefaction controlled at 1-2%; S2. The temperature of the liquefied liquid is controlled at 55-60℃, the pH value is controlled at 4.2-7.2, and debranching enzyme and β-amylase are added for saccharification treatment; S3. After saccharification is complete, add ethanol to a concentration of 20% and continue the reaction for 2 hours. Then, increase the ethanol concentration to 40% and continue the reaction for 2 hours. S4. Cool to 30-35℃, add ethanol to 80% concentration to inactivate enzymes and allow to stand for crystallization; S5. Centrifuge to separate the crystals, and dry to obtain maltose.

2. The production process of high-purity maltose syrup according to claim 1, characterized in that: In step S1, the mass percentage of starch slurry is 5-10%, the pH value is adjusted to 5.8-6.2, and the liquefaction temperature is 105-115℃.

3. The production process of high-purity maltose syrup according to claim 1, characterized in that: In step S1, a heat-resistant α-amylase is added during liquefaction, with an enzyme addition amount of 0.5-0.8 kg / tds starch paste.

4. The production process of high-purity maltose syrup according to claim 1, characterized in that: In step S2, pullulanase is first added for debranching and preliminary saccharification. After saccharification, the temperature is raised to 60-65℃ and the pH is controlled at 6.0-7.

2. Maltohexasaccharide synthase is added to saccharify and generate substrates. Then, β-amylase is added for complete saccharification.

5. The production process of high-purity maltose syrup according to claim 4, characterized in that: Pullulanase was added at a rate of 8-10 kg / tds of liquefied liquid, and the saccharification time was 2 hours.

6. The production process of a high-purity maltose syrup according to claim 4, characterized in that: The amount of maltohexasaccharide generating enzyme added is 14-25 kg / tds liquefied liquid.

7. The production process of high-purity maltose syrup according to claim 4, characterized in that: The amount of β-amylase added is 2-3 kg / tds of liquefied liquid, and the β-amylase is added when the concentration of maltohexaose in the liquefied liquid is 50%.

8. The production process of high-purity maltose syrup according to claim 1, characterized in that: In step S3, ethanol is initially added to the liquefied liquid when the maltose content is ≥85% and the increase rate is <0.5%.

9. The production process of high-purity maltose syrup according to claim 1, characterized in that: In step S5, the separated mother liquor is fed into an ethanol distillation column for recovery, and the remaining sugar solution is purified by activated carbon and then fed into a simulated moving bed for chromatographic separation.

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