Method for producing starch sugar from food-grade corn flour

Abstract

The invention relates to the technical field of food processing, in particular to a method for producing starch sugar from food-grade corn flour. The invention develops the method for preparing the starch sugar by taking the edible-grade corn flour as the raw material, the method for producing the starch sugar by taking corn starch as the raw material in the traditional process is changed, the problems of pollution, peculiar smell and equipment corrosion caused by sulfurous acid soaking in the corn starch production process are solved, the adopted raw materials are green and organic raw materials, and the cost is low. The produced starch sugar product is higher in nutritional value, and compared with a traditional technological method, the equipment investment is small, the operation cost is low, the byproduct value is high, and the method has wide market application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to a method for producing starch sugar from edible-grade corn flour. Background Art

[0002] At present, the traditional method of producing starch sugar from corn is to extract the starch from corn and then use the double enzyme method to produce starch sugar. The traditional method has serious environmental pollution, large amounts of wastewater discharge, low starch extraction rate, large equipment investment, severe corrosion, and complex process.

[0003] Therefore, inventing a process for producing starch sugar from edible-grade corn flour has important market value. Summary of the invention

[0004] The invention develops a method for preparing starch sugar by taking edible-grade corn flour as raw material, comprising: taking edible-grade corn flour as raw material, mixing slurry, adding mixed liquefaction enzyme to carry out jet liquefaction, maintaining for a period of time, flash evaporation and cooling, and then maintaining laminar flow; maintaining the temperature and adjusting the pH to 2.5-3.5, filtering to obtain sugar residue and filtrate; cooling the filtrate and adjusting the pH to 4-5, then adding saccharifying enzyme to saccharify, and then decolorizing, ion exchanging, evaporating and crystallizing to obtain starch sugar; the mixed liquefaction enzyme is a mixture of high-temperature resistant α-amylase, medium-temperature α-amylase and low-temperature α-amylase.

[0005] Because corn starch is used as raw material to produce starch sugar by double enzyme method in traditional process, there is no precedent of directly producing starch sugar using edible corn flour. Therefore, the present invention has confirmed that edible corn flour can be used as the production raw material of starch sugar through multiple experiments. However, the present invention finds that the high temperature resistant α-amylase in traditional process cannot be well liquefied for edible corn flour, therefore, the present invention develops a composite enzyme suitable for liquefaction of edible corn flour, including high temperature resistant α-amylase, medium temperature α-amylase and low temperature α-amylase, so as to realize the liquefaction of edible corn flour. In addition, the present invention also finds that the production of starch sugar with edible corn flour as raw material is filtered after saccharification, and it is found that the sugar liquid color is dark and the sugar residue color is light, which seriously affects the quality of sugar liquid and corn protein powder, and the present invention finds that high temperature filtration after liquefaction can make the quality of sugar liquid and corn protein powder significantly improved.

[0006] In the present invention, the edible-grade corn flour is edible-grade corn flour that complies with the national standard GB / T 10463-2008.

[0007] Preferably, the parameters of edible-grade corn flour are as follows: crude fat content (dry basis) / %≤2, fineness all passing through CQ10 sieve, fatty acid value (dry basis) (calculated as KOH) / mg / 100g≤60, ash content (dry basis) / %≤1, sand content≤0.02, magnetic metal / g / kg≤0.003, moisture content%≤14.5, color, smell and taste are the inherent color, smell and taste of corn.

[0008] Preferably, in the mixed liquefaction enzyme, the weight ratio of the high-temperature resistant α-amylase, the medium-temperature α-amylase and the low-temperature α-amylase is (5-10): (1-3): 1.

[0009] More preferably, in the mixed liquefaction enzyme, the weight ratio of the high-temperature resistant α-amylase, the medium-temperature α-amylase and the low-temperature α-amylase is (5-7): (1.5-2.5):1.

[0010] Most preferably, in the mixed liquefaction enzyme, the weight ratio of the high-temperature resistant α-amylase, the medium-temperature α-amylase and the low-temperature α-amylase is (5-6): (1.5-2.5):1.

[0011] Preferably, the action temperature of the high-temperature resistant α-amylase is 100-110°C; the action temperature of the medium-temperature α-amylase is 50-70°C; and the action temperature of the low-temperature α-amylase is 30-50°C.

[0012] Preferably, the slurry preparation includes: mixing food-grade corn flour with water to obtain a corn flour suspension material with a concentration of 25% to 35%.

[0013] Preferably, the added amount of the mixed liquefaction enzyme is 1 / 10,000 to 5 / 10,000 of the dry weight of edible-grade corn flour.

[0014] Preferably, the temperature of the spray liquefaction is 100°C to 110°C; and the temperature is maintained at 100°C to 110°C for 5 to 8 minutes after the spray liquefaction.

[0015] Preferably, a mixed liquefaction enzyme is added for jet liquefaction, which is maintained for 5 to 8 minutes, followed by flash evaporation and cooling, and then laminar flow is maintained.

[0016] Preferably, after the flash evaporation temperature is reduced to 96-98° C., the laminar flow is maintained for 90-120 min.

[0017] Preferably, the temperature is maintained and the pH is adjusted to 2.8-3.2 before filtering to obtain sugar residue and filtrate.

[0018] Preferably, the filtration is performed by plate and frame filtration; and / or the sugar residue is washed, crushed, dried and then packaged as a corn gluten meal product.

[0019] Preferably, the filtrate is cooled to 60-62° C. and the pH is adjusted to 4.1-4.5, and then saccharifying enzyme is added at 1% to 5% of the weight of the dry matter in the filtrate for saccharification.

[0020] Preferably, the saccharification time is 30 to 40 hours.

[0021] Preferably, the decolorization is carried out using activated carbon.

[0022] Preferably, activated carbon is used for decolorization and then filtration, and the clear liquid is subjected to ion exchange to remove ions in the saccharified liquid, and the starch sugar ion exchange liquid is evaporated, concentrated, crystallized, and dried to obtain starch sugar.

[0023] Preferably, the condensed water after evaporation and concentration is returned to the slurry preparation step for use.

[0024] Preferably, concentrated sulfuric acid and sodium hydroxide are used to adjust the pH.

[0025] Preferably, the DE value of the sample after saccharification is above 98%, and the powder sugar conversion rate is above 105%.

[0026] Compared with the prior art, the present invention has the following beneficial effects: 1. Green production: The double enzyme method is used to produce starch sugar using edible corn flour as raw material, which changes the traditional method of producing starch sugar using corn starch as raw material, and solves the pollution problem, odor problem and equipment corrosion problem caused by sulfurous acid immersion in the corn starch production process.

[0027] 2. Improve product yield and product quality: The present invention, through process control, makes the powder sugar conversion rate 0.5% higher than the original process method. The product quality is stable, the raw materials used are green organic raw materials, and the produced starch sugar products have higher nutritional value.

[0028] 3. Reduce production costs: Compared with traditional process methods, the equipment investment is small, the operating cost is low, and the consumption of steam and electricity is reduced.

[0029] 4. High value of by-products: The by-product corn gluten meal is a matured protein meal, which is beneficial for animals to absorb and utilize. The fat content in corn gluten meal reaches 6~8%, which is a green high-fat corn gluten meal.

[0030] 5. Meet market demand: The present invention can be selected according to different production requirements, is not restricted by environmental protection requirements, adapts to different production scales and market demands, and has strong flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] If no specific techniques or conditions are specified in the examples, all are carried out according to conventional methods or the techniques or conditions described in the literature in the field, or according to the product instructions. If no manufacturer is specified for the reagents and instruments used, all are conventional products that can be purchased through regular channels.

[0034] The brand of the high temperature resistant α-amylase in the following embodiments is: Novozyme Licole α-high temperature amylase; the brand of the medium temperature α-amylase is: Novozyme α-medium temperature amylase; the brand of the low temperature α-amylase is: Novozyme α-low temperature amylase. The detection methods of DE value, absolute dry sugar content and powder sugar conversion rate in the following embodiments refer to GB / T20882.2-2021.

[0035] Example 1

[0036] This embodiment provides a method for preparing starch sugar using edible corn flour as raw material. The process flow diagram is shown in FIG. Figure 1 As shown, the steps are as follows: (1) Slurry preparation: slowly and uniformly add 3000 kg of edible-grade corn flour (in compliance with GB / T 10463-2008) into 6677 kg of 58°C hot water, and stir at 60 rpm to form edible corn flour slurry; (2) Adding mixed liquefaction enzyme: adding mixed liquefaction enzyme (high temperature resistant α-amylase, medium temperature α-amylase, and low temperature α-amylase in a weight ratio of 1.75:0.5:0.25) to edible corn flour slurry at a ratio of 3 / 10,000 (774 g) based on the dry basis of edible corn flour to prepare a mixed material; (3) High-temperature jet liquefaction: The mixed material in step (2) is subjected to high-temperature jet liquefaction at 105°C, maintained for 6 min, and then flash-cooled to 97°C. The mixture is then fed into a laminar flow tank, maintained for 90 min, and then fed into a sub-column tank.

[0037] (4) High-temperature pH adjustment and filtration: Maintain 97°C and use concentrated sulfuric acid to adjust the pH value to 3.0, then use a high-temperature resistant plate and frame filter press to filter to obtain sugar residue and filtrate; the sugar residue output is 360 kg, and the moisture content is 14%; the sugar residue is cleaned, crushed, dried, and packaged as corn protein powder.

[0038] (5) Saccharification: The filtrate was cooled to 60°C and the pH was adjusted to 4.3 using liquid alkali (sodium hydroxide solution). Saccharifying enzyme was added and saccharified for 35 hours to obtain saccharified liquid. The DE value of the sample was 99%, the dry matter content was 23.5%, the total weight was 10300kg, the dry sugar content was 2430.5kg, and the powder sugar conversion rate was 107.05%.

[0039] (6) Post-saccharification treatment: The saccharification liquid is decolorized and filtered with activated carbon, and the starch sugar decolorization liquid enters the ion exchange system to remove ions to obtain starch sugar ion exchange liquid. The starch sugar ion exchange liquid enters the evaporator for vacuum low-temperature evaporation to obtain starch sugar concentrated liquid. The starch sugar concentrated liquid enters the crystallizer for crystallization to obtain starch sugar crystal liquid. The starch sugar crystal liquid enters the separator for solid-liquid separation to obtain starch sugar crystals. The starch sugar crystals enter the drying system for drying to obtain starch sugar products.

[0040] Example 2

[0041] This embodiment provides a method for preparing starch sugar using edible corn flour as raw material, and the steps are only different from those in Example 1: The mixed liquefaction enzyme is a mixture of high temperature resistant a-amylase, medium temperature a-amylase and low temperature a-amylase in a weight ratio of 1.25:0.5:0.25.

[0042] The DE value of the saccharified liquid was detected to be 99.5%, the dry matter content was 23.4%, the total weight was 10315 kg, the absolute dry sugar content was 2413.71 kg, and the powdered sugar conversion rate was 107.1%.

[0043] Example 3

[0044] This embodiment provides a method for preparing starch sugar using edible corn flour as raw material, and the steps are only different from those in Example 1: The mixed liquefaction enzyme is a mixture of high temperature resistant a-amylase, medium temperature a-amylase and low temperature a-amylase in a weight ratio of 2.5:0.75:0.25.

[0045] The DE value of the saccharified liquid was 98.2%, the dry matter content was 23.8%, the total weight was 10340 kg, the absolute dry sugar content was 2460.92 kg, and the powder sugar conversion rate was 106.1%.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing starch sugar from edible-grade corn flour, characterized in that: include: Edible corn flour is used as raw material. After slurry adjustment, mixed liquefaction enzyme is added for jet liquefaction. After a period of time, flash evaporation is performed to cool the mixture, and then laminar flow is maintained. The temperature is maintained and the pH is adjusted to 2.5-3.5 before filtering to obtain sugar residue and filtrate; the filtrate is cooled and the pH is adjusted to 4-5, and then saccharifying enzyme is added for saccharification, and then starch sugar is obtained through decolorization, ion exchange, evaporation and crystallization; the mixed liquefaction enzyme is a mixture of high-temperature resistant α-amylase, medium-temperature α-amylase and low-temperature α-amylase.

2. The method according to claim 1, characterized in that In the mixed liquefaction enzyme, the weight ratio of the high-temperature resistant α-amylase, the medium-temperature α-amylase and the low-temperature α-amylase is (5-10): (1-3):

1.

3. The method according to claim 1, characterized in that The slurry preparation includes: mixing food-grade corn flour with water to obtain a corn flour suspension material with a concentration of 25% to 35%.

4. The method according to claim 1, characterized in that: The added amount of the mixed liquefaction enzyme is 1 / 10,000 to 5 / 10,000 of the dry weight of the edible-grade corn flour.

5. The method according to claim 1, characterized in that The temperature of the spray liquefaction is 100° C. to 110° C.; after the spray liquefaction, the temperature is maintained at 100° C. to 110° C. for 5 to 8 minutes.

6. The method according to claim 1, characterized in that After flash cooling to 96~98℃, the laminar flow is maintained for 90~120min.

7. The method according to claim 1, characterized in that The filtration is performed by plate and frame filtration; and / or the sugar residue is cleaned, crushed, dried and then packaged as a corn gluten powder product.

8. The method according to claim 1, characterized in that The filtrate is cooled to 60-62°C and the pH is adjusted to 4.1-4.5, and then saccharifying enzyme is added according to 1% to 5% of the weight of the dry matter in the filtrate for saccharification.

9. The method according to claim 1, characterized in that: The decolorization adopts activated carbon decolorization.

10. The method according to claim 1, characterized in that The DE value of the sample after saccharification was above 98%, and the powdered sugar conversion rate was above 105%.

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