Processing technology of maltodextrin with low DE value

Abstract

The invention discloses a processing technology of low-DE-value maltodextrin, belongs to the technical field of maltodextrin, and aims to solve the problems of insufficient hydrolysis end point control precision and poor product batch stability when the low-DE-value maltodextrin is prepared by the existing technology. The process comprises the following steps: humidifying starch until the water content is 18-22%, carrying out instantaneous treatment for 15-30 seconds by using saturated steam at 105-110 DEG C to form a surface gelatinization layer, dispersing into 20-30% suspension, carrying out pulsed electric field treatment under the conditions of 25-35 kV / cm electric field intensity and 80-150 pulse counts, carrying out enzymolysis by using medium-temperature alpha-amylase, inactivating enzyme, filtering, concentrating and drying to obtain the product. According to the technology, starch is pretreated through cooperation of saturated steam instantaneous surface gelatinization and pulsed electric field treatment, then enzymolysis is conducted through medium-temperature alpha-amylase, the starch surface and interior hydrolysis rates are effectively regulated and controlled to tend to be synchronous, and therefore the batch stability of low-DE-value products is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of maltodextrin technology and relates to a processing technology for low DE value maltodextrin. Background Technology

[0002] Maltodextrin is a polysaccharide mixture with a degree of polymerization between starch and sugar, produced from starch through hydrolysis. Its core quality indicator, the DE value (glucose equivalent), directly reflects the degree of starch hydrolysis: the lower the DE value, the higher the proportion of long-chain polysaccharides in the product. These low-DE maltodextrins (usually referring to DE values ​​less than 10) are widely used in the food, pharmaceutical, and cosmetic industries as thickeners, fillers, and flavor carriers due to their high viscosity, low hygroscopicity, and good carrier properties. However, current methods for preparing low-DE products using a single enzymatic process face a technical bottleneck: insufficient precision in controlling the hydrolysis endpoint leads to large fluctuations in the product's DE value and poor batch-to-batch stability. Summary of the Invention

[0003] The purpose of this invention is to provide a processing technology for low DE value maltodextrin. By pretreating starch through saturated steam instantaneous surface gelatinization and pulsed electric field treatment, followed by medium-temperature α-amylase enzymatic hydrolysis, the hydrolysis rate of starch inside and outside is effectively controlled to be synchronized, thereby significantly improving the batch stability of low DE value products.

[0004] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a processing method for low DE-value maltodextrin, comprising the following steps: S1. Adjust and balance the moisture content of the starch to 18%-22% (w / w); S2. The starch processed in step S1 is treated in a saturated steam environment at 105℃-110℃ for 15-30 seconds to form a gelatinized layer on the surface of the starch, and then cooled for later use. S3. Disperse the surface-gelatinized starch in water to prepare a suspension with a concentration of 20%-30% (w / w); S4. The suspension is subjected to pulsed electric field treatment under the conditions of electric field strength of 25-35kV / cm, pulse number of 80-150, and system temperature of 25-45℃. S5. The suspension treated with pulsed electric field is subjected to enzymatic hydrolysis. After the reaction is completed, the enzyme is inactivated, filtered, concentrated and dried to obtain the low DE value maltodextrin.

[0005] Preferably, in step S4, the waveform of the pulsed electric field is a square wave.

[0006] Preferably, in step S4, the width of a single pulse in the pulsed electric field is 10-30 μs.

[0007] Preferably, in step S4, the suspension passes through the pulsed electric field treatment area in a laminar flow state, and the flow rate of the suspension is 5-10 L / min.

[0008] Preferably, in step S5, the enzymatic hydrolysis reaction is carried out using medium-temperature α-amylase.

[0009] Preferably, in step S5, the temperature of the suspension is adjusted to 60℃-65℃ and the pH of the suspension is adjusted to 6.0-6.5 before the enzymatic hydrolysis reaction.

[0010] Preferably, in step S5, the amount of medium-temperature α-amylase added is 150-300 U / g dry starch.

[0011] Preferably, in step S5, the enzymatic hydrolysis time is 30-40 minutes.

[0012] Preferably, the starch is selected from at least one of corn starch, tapioca starch, potato starch, and wheat starch.

[0013] Secondly, the present invention provides a low DE value maltodextrin product, which is obtained by the processing technology described above.

[0014] The beneficial effects of this invention are: This invention utilizes instantaneous saturated steam treatment to form a gelatinized layer on the starch surface, effectively slowing down the initial enzymatic hydrolysis rate at starch surface sites. Pulsed electric field treatment, on the other hand, constructs mass transfer channels within the starch, promoting enzyme molecule penetration and accelerating the internal hydrolysis process. The synergistic effect of these two methods significantly narrows the hydrolysis rate difference between the surface and interior of the starch, transforming the traditional asynchronous hydrolysis process into a synergistic surface-interior hydrolysis. This optimizes enzymatic hydrolysis kinetics at the substrate structure level, enhances the controllability of the hydrolysis process, and effectively improves the batch-to-batch quality fluctuations in traditional single-enzyme processes, ensuring the quality stability of low-DE-value maltodextrin. Detailed Implementation

[0015] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0016] The following descriptions of some of the raw materials used in the examples and comparative examples are as follows: The food-grade corn starch is sourced from Jinan Tianjiang Chemical Technology Co., Ltd. The food-grade cassava starch comes from Hebei Liqia Biotechnology Co., Ltd. The food-grade potato starch comes from Shandong Fuhe Biotechnology Co., Ltd. The mesophilic α-amylase was obtained from Hubei Xinghengye Technology Co., Ltd., with an enzyme activity of 10,000 U / g. Except for the raw materials explicitly mentioned above, all other raw materials not specifically mentioned are conventional industrial-grade products that can be easily obtained through commercial channels.

[0017] Example 1

[0018] This embodiment provides a processing technology for low DE value maltodextrin, the specific steps of which are as follows: S1. Starch Moisture Balancing: Place food-grade corn starch in a high-speed shear mixer. Start the mixer (300 r / min) and spray deionized water evenly into the starch using the built-in atomizing nozzle. Continue stirring for 10 minutes until the starch moisture content initially reaches 20% (w / w). Transfer the humidified starch to a plastic container, seal it, and place it in a constant temperature and humidity room (25℃, 65% relative humidity) for 16 hours to equilibrate. During this period, manually stir the starch every 4 hours to ensure moisture balance. After equilibration, take samples for testing to confirm that the final starch moisture content is stable at 20% (w / w).

[0019] S2. Instantaneous Steam Gelatinization: The moisture-balanced starch is evenly spread onto the conveyor belt of a stainless steel mesh belt continuous steam treatment machine, with a spread thickness controlled at 3 mm. The steam generator is started, and the saturated steam temperature is adjusted to 108℃ and the steam pressure to 0.12 MPa. The conveyor belt runs at a constant speed, exposing the starch to the saturated steam environment for 20 seconds, during which steam nozzles evenly cover the starch layer surface. After treatment, a uniform gelatinized layer forms on the starch surface, which is immediately cooled through a cooling duct (air velocity 2 m / s, temperature 20℃) to prevent over-gelatinization or clumping.

[0020] S3. Preparation of suspension: Disperse the surface-gelatinized starch in room temperature deionized water and stir at a rate of 90 r / min until there are no lumps to prepare a starch suspension with a concentration of 25% (w / w). Adjust the temperature to 35℃ and set aside.

[0021] S4. Pulsed electric field treatment: Pump the suspension into the pulsed electric field treatment equipment and control the suspension to pass through the treatment area in a laminar flow state with a flow rate of 8 L / min. Adjust the pulsed electric field parameters as follows: electric field strength 30 kV / cm, number of pulses 120, system temperature maintained at 35℃, pulse waveform is square wave, and single pulse width is 20 μs.

[0022] S5. Enzymatic hydrolysis and post-treatment: The suspension treated with a pulsed electric field was transferred to an enzymatic hydrolysis reactor. The reaction system temperature was adjusted to 62℃ and the pH value to 6.2. Medium-temperature α-amylase was added at a dosage of 220 U / g dry starch. The stirring rate was maintained at 55 r / min, and hydrolysis was carried out at a constant temperature and pH for 35 minutes. After enzymatic hydrolysis, the reaction system was heated to 98℃ and kept at this temperature for 18 minutes to inactivate the enzyme. Subsequently, impurities were removed by plate and frame filtration (filter cloth pore size 150 mesh) to obtain the filtrate. The filtrate was transferred to a vacuum concentration device and concentrated to a solid content of 45% (w / w) at 65℃ and -0.085 MPa. Finally, spray drying was performed, controlling the inlet air temperature at 190℃ and the outlet air temperature at 85℃. After drying, the powdered product was collected, which is the low DE value maltodextrin.

[0023] Example 2

[0024] This embodiment provides a processing technology for low DE value maltodextrin, the specific steps of which are as follows: S1. Starch Moisture Balancing: Place food-grade tapioca starch in a high-speed shear mixer. Start the mixer (300 r / min) and spray deionized water evenly into the starch using the built-in atomizing nozzle. Continue stirring for 10 minutes until the starch moisture content initially reaches 18% (w / w). Transfer the humidified starch to a plastic container, seal it, and place it in a constant temperature and humidity room (25℃, 65% relative humidity) for 16 hours to equilibrate. During this period, manually turn the starch every 4 hours to ensure moisture balance. After equilibration, take samples for testing to confirm that the final starch moisture content is stable at 18% (w / w).

[0025] S2. Instantaneous Steam Gelatinization: The moisture-balanced starch is evenly spread onto the conveyor belt of a stainless steel mesh belt continuous steam treatment machine, with a spread thickness controlled at 3 mm. The steam generator is started, and the saturated steam temperature is adjusted to 108℃ and the steam pressure to 0.12 MPa. The conveyor belt runs at a constant speed, exposing the starch to the saturated steam environment for 18 seconds, during which steam nozzles evenly cover the starch layer surface. After treatment, a uniform gelatinized layer forms on the starch surface, which is immediately cooled through a cooling duct (air velocity 2 m / s, temperature 20℃) to prevent over-gelatinization or clumping.

[0026] S3. Preparation of suspension: Disperse the surface-gelatinized cassava starch in room temperature deionized water and stir at a rate of 80 r / min until it is completely dispersed and free of lumps to prepare a starch suspension with a concentration of 20% (w / w). Adjust the temperature to 25℃ and set aside.

[0027] S4. Pulsed electric field treatment: Pump the suspension into the pulsed electric field treatment equipment and control the suspension to pass through the treatment area in a laminar flow state with a flow rate of 5 L / min. Adjust the pulsed electric field parameters as follows: electric field strength 25 kV / cm, number of pulses 80, system temperature maintained at 25℃, pulse waveform is square wave, and single pulse width is 10 μs.

[0028] S5. Enzymatic hydrolysis and post-treatment: The suspension treated with a pulsed electric field is transferred to an enzymatic hydrolysis reactor. The system temperature is adjusted to 60℃ using a constant temperature water bath. An appropriate amount of buffer solution is added to adjust the pH to 6.0. Then, medium-temperature α-amylase (enzyme activity 10000 U / g) is added at a rate of 180 U / g dry starch. The stirring rate is maintained at 50 r / min, and hydrolysis is carried out for 30 minutes under constant temperature and pH conditions. After enzymatic hydrolysis, the reaction system is rapidly heated to 95℃ and kept at this temperature for 20 minutes to completely inactivate the amylase. Then, the mixture is filtered using a vacuum filtration method (filter cloth pore size 100 mesh) to remove fine residues that have not been completely hydrolyzed, resulting in a clear filtrate. The filtrate is sent to a vacuum concentration tank and concentrated to a solid content of 40% (w / w) at 60℃ and -0.08 MPa. Finally, spray drying is performed, controlling the inlet air temperature at 180℃ and the outlet air temperature at 80℃. After drying, the powdered product is collected, which is the low DE value maltodextrin.

[0029] Example 3

[0030] This embodiment provides a processing technology for low DE value maltodextrin, the specific steps of which are as follows: S1. Starch Moisture Balancing: Place food-grade potato starch in a high-speed shear mixer. Start the mixer (300 r / min) and spray deionized water evenly into the starch using the built-in atomizing nozzle. Continue stirring for 10 minutes until the starch moisture content initially reaches 22% (w / w). Transfer the humidified starch to a plastic container, seal it, and place it in a constant temperature and humidity room (25℃, 65% relative humidity) for 16 hours to equilibrate. During this period, manually turn the starch every 4 hours to ensure moisture balance. After equilibration, take samples for testing to confirm that the final starch moisture content is stable at 22% (w / w).

[0031] S2. Instantaneous Steam Gelatinization: The moisture-balanced starch is evenly spread onto the conveyor belt of a stainless steel mesh belt continuous steam treatment machine, with a spread thickness controlled at 3 mm. The steam generator is started, and the saturated steam temperature is adjusted to 108℃ and the steam pressure to 0.12 MPa. The conveyor belt runs at a constant speed, exposing the starch to the saturated steam environment for 25 seconds, during which steam nozzles evenly cover the surface of the starch layer. After treatment, a uniform gelatinized layer forms on the starch surface, which is immediately cooled through a cooling duct (air velocity 2 m / s, temperature 20℃) to prevent over-gelatinization or clumping.

[0032] S3. Preparation of suspension: Disperse the surface-gelatinized potato starch in room temperature deionized water and stir at a high speed of 100 r / min until it is completely homogeneous and free of lumps to prepare a starch suspension with a concentration of 30% (w / w). Then adjust the temperature to 45℃ and set aside.

[0033] S4. Pulsed electric field treatment: Pump the suspension into the pulsed electric field treatment equipment and control the suspension to pass through the treatment area in a laminar flow state with a flow rate of 10 L / min. Adjust the pulsed electric field parameters as follows: electric field strength 35 kV / cm, number of pulses 150, system temperature maintained at 45℃, pulse waveform is square wave, and single pulse width is 30 μs.

[0034] S5. Enzymatic hydrolysis and post-treatment: The suspension treated with a pulsed electric field is transferred to an enzymatic hydrolysis reactor. The system temperature is adjusted to 65℃ using a heat-conducting oil bath. Phosphate buffer is added to adjust the pH to 6.5, followed by the addition of mesophilic α-amylase (enzyme activity 10000 U / g) at a dosage of 280 U / g dry starch. The stirring rate is maintained at 60 r / min, and hydrolysis is carried out for 40 minutes under constant temperature and pH conditions. After enzymatic hydrolysis, the reaction system is heated to 100℃ and kept at this temperature for 15 minutes to completely inactivate the enzyme. Then, plate and frame filtration (filter cloth pore size 200 mesh) is used to remove impurities and trace amounts of unhydrolyzed starch particles, resulting in a clear and transparent filtrate. The filtrate is sent to a vacuum concentration device and concentrated to a solid content of 50% (w / w) at 70℃ and -0.09 MPa. Finally, spray drying is performed, controlling the inlet air temperature at 200℃ and the outlet air temperature at 90℃. After drying, the powdered product is collected, which is the low DE value maltodextrin.

[0035] Comparative Example 1 The difference from Example 1 is that the S2 instantaneous surface gelatinization step and the S4 pulsed electric field treatment step are omitted. Instead, a conventional single-enzyme process is used to directly disperse the corn starch after S1 humidity balancing into a suspension, and then directly transfer it into the enzymatic hydrolysis reactor. The subsequent enzymatic hydrolysis parameters, post-treatment steps and parameters are completely consistent with those of Example 1.

[0036] Comparative Example 2 The difference from Example 1 is that the S2 instantaneous surface gelatinization step is retained, the S4 pulsed electric field treatment step is omitted, and the suspension after S3 is directly transferred into the enzymatic hydrolysis reactor. The subsequent enzymatic hydrolysis parameters, post-treatment steps and parameters are completely consistent with those of Example 1.

[0037] Comparative Example 3 The difference from Example 1 is that the S4 pulse electric field treatment step is retained, the S2 instantaneous surface gelatinization step is omitted, and the corn starch after S1 humidity balancing is directly subjected to S3 suspension preparation and subsequent treatment. The S4 pulse electric field parameters, S5 enzymatic hydrolysis parameters, and post-treatment steps are completely consistent with those of Example 1.

[0038] Comparative Example 4 The difference from Example 1 is that the order of steps S2 and S4 is adjusted. Pulsed electric field treatment is performed first, followed by steam surface gelatinization. Specifically, after S1 humidity balancing, S3 suspension preparation is performed directly, followed by S4 pulsed electric field treatment (parameters are the same as in Example 1). After the treatment is completed, the suspension is dried to a water content of 20%, and then S2 steam treatment is performed (parameters are the same as in Example 1). The subsequent enzymatic hydrolysis and post-treatment steps are the same as in Example 1.

[0039] test 1. Batch stability testing A. Test Object Examples 1, 2, and 3 of this invention; Comparative Examples 1, 2, 3, and 4.

[0040] B. Testing Methods and Procedures For each group of test objects, three batches of samples were prepared in parallel and repeatedly according to the corresponding process parameters. Each batch of samples independently completed the entire process from starch conditioning to spray drying to ensure that the process parameters of each batch were strictly consistent to avoid operational errors. Approximately 2g of each batch of sample was weighed in an electronic balance with an accuracy of 0.1mg, dried in a 105℃ drying oven to constant weight, cooled to room temperature, and then accurately weighed 0.5g (denoted as m, unit g). The sample was placed in a 250mL volumetric flask, dissolved in deionized water, and diluted to the mark. The sample stock solution was obtained by shaking well. The DE value was determined by the national standard Fehling's reagent titration method. 5mL each of Fehling's reagent solution A and B were placed in a 250mL Erlenmeyer flask, 10mL of deionized water was added, and the solution was shaken well. The solution was then placed in a constant temperature water bath with a temperature control accuracy of ±0.5℃ and boiled for 2min. The boiled Fehling's reagent was titrated with the sample stock solution using a 50mL burette. During the titration, the solution was kept at a gentle boil. Near the endpoint, 2 drops of nitrate solution were added. Using methylene blue indicator, continue titrating until the blue color completely fades and does not recover within 30 seconds. Record the volume of the sample stock solution consumed (denoted as V, in mL). Simultaneously, perform a blank experiment: boil equal volumes of Fehling's reagent A and B and deionized water, then titrate with deionized water to the endpoint and record the volume consumed (denoted as V0, in mL). Prepare a 0.1 mg / mL standard solution using glucose standard with a purity ≥99.8% and plot a standard curve. Calculate the reducing sugar content in the sample (calculated as glucose) using the formula DE value = (reducing sugar mass / sample dry matter mass) × 100%. If pH adjustment is needed, use 1 mol / L hydrochloric acid solution and 1 mol / L sodium hydroxide solution. For each of the three batches of samples, calculate the mean (X), standard deviation (SD), and coefficient of variation (CV) of the DE value, where CV = (SD / X) × 100%. The smaller the coefficient of variation, the stronger the batch stability.

[0041] Batch stability test data are shown in Table 1.

[0042] Table 1

[0043] As shown in Table 1, the synergistic treatment process of saturated steam instantaneous gelatinization and pulsed electric field in Examples 1-3 of this invention resulted in three batches of maltodextrin with extremely low coefficients of variation (CV) of DE values ​​(1.10%-1.25%), significantly lower than all comparative examples. This indicates that the synergistic pretreatment process of this invention can greatly improve the batch uniformity and stability of the product. In contrast, the batch-to-batch DE value fluctuation of Comparative Example 1, which used the traditional single enzymatic method, was extremely large (CV=10.75%). While Comparative Examples 2 (steam gelatinization only) and 3 (pulsed electric field only), which used only single pretreatment techniques, showed some improvement, their stability (CVs of 3.85% and 4.35%, respectively) was far inferior to that of this invention. Comparative Example 4, which adjusted the order of pretreatment steps, showed better stability (CV=2.56%) than single pretreatment but worse than the correct order of this invention. This proves that the step order of "first steam gelatinization to form a surface barrier, then pulsed electric field to construct internal channels" is crucial for achieving precise synergistic control of the starch surface and internal hydrolysis rate and is the key to obtaining high batch stability.

[0044] 2. Dynamic changes in reducing sugars during enzymatic hydrolysis.

[0045] A. Test Object Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4.

[0046] B. Testing Methods and Procedures For each test subject, one enzymatic hydrolysis reaction was started synchronously according to the corresponding process, ensuring that the parameters such as the volume, temperature, pH, and enzyme dosage of the enzymatic hydrolysis system were completely consistent with the example / comparative example, and each group of enzymatic hydrolysis processes was repeated synchronously 3 times. After the enzymatic hydrolysis reaction started, at 5 min, 15 min, 25 min, and 35 min, 2 mL of enzymatic hydrolysate was taken with a 1 mL pipette and quickly injected into a test tube pre-filled with 2 mL of boiling water. The test tube was then placed in a constant temperature water bath and heated in a boiling water bath for 5 min to completely inactivate the enzyme (terminate the hydrolysis reaction). After cooling to room temperature, the sample was set aside. The enzyme-inactivated sample was centrifuged in a centrifuge at a speed of ≥8000 r / min for 10 min, and the supernatant was used as the test solution. The test solution was diluted 10 times with deionized water. The reducing sugar content was determined using the DNS method. A series of glucose standard solutions with a purity of ≥99.8% and a concentration gradient (0.1-1.0 mg / mL) were prepared. 1 mL of each solution was placed in a test tube and added to the test tube. 1 mL of DNS reagent (3,5-dinitrosalicylic acid) was shaken well and heated in a boiling water bath for 5 min. After cooling to room temperature, deionized water was added to bring the volume to 10 mL. The absorbance was measured at 540 nm using a UV-Vis spectrophotometer. A standard curve was plotted with glucose concentration on the x-axis and absorbance on the y-axis, and a regression equation was obtained. The pH of the enzymatic hydrolysis system was adjusted using a pH 6.0-6.5 phosphate buffer. If alkalinity adjustment is required, a 2 mol / L sodium hydroxide solution can be used. 1 mL of the diluted test solution was taken, and the absorbance was measured according to the standard curve plotting procedure. The absorbance was then substituted into the regression equation to calculate the reducing sugar content (calculated as glucose) in the test solution. This was then converted to the actual reducing sugar content in the enzymatic hydrolysis system (unit: mg / g dry starch). The average reducing sugar content at each time point was taken as the final data. The average hydrolysis rate per unit time for each group was calculated (mg / (g·min), total reducing sugar increment / enzymatic hydrolysis time 35 min).

[0047] The test data on the dynamic changes of reducing sugars during the enzymatic hydrolysis process are shown in Table 2.

[0048] Table 2

[0049] As shown in Table 2, in terms of enzymatic hydrolysis kinetics, the reducing sugar formation curve of Example 1 was the smoothest and most balanced. Its initial stage (5 min) reducing sugar formation (12.3 mg / g) was significantly lower than that of Comparative Example 1 (40.2 mg / g) and Comparative Example 3 (30.4 mg / g), indicating that the surface gelatinization layer effectively delayed the rapid attack of the enzyme on the starch surface. In the middle and later stages (15-35 min), the hydrolysis rate was maintained, finally reaching a reducing sugar level comparable to other groups at 35 min. This shows that the synergistic process of the present invention successfully transformed the hydrolysis reaction from the traditional asynchronous mode of "fast first, slow later" to a mode of "synergistic effect and balanced rate." Comparative Example 2, due to only surface gelatinization, experienced excessive inhibition of initial hydrolysis (only 5.1 mg / g at 5 min), leading to increased pressure in the later stages. Comparative Example 4, due to the reversed step sequence, had a kinetic curve between Comparative Example 2 and Example 1, but its balance was still insufficient. The optimization of enzymatic hydrolysis kinetics directly improved the controllability of the hydrolysis endpoint, which is the fundamental reason for achieving batch stability of low DE value products.

[0050] In summary, the synergistic pretreatment process of "saturated steam instantaneous surface gelatinization" and "pulsed electric field treatment" provided by this invention effectively harmonizes the rate difference between surface and internal hydrolysis through an "external slow and internal fast" mechanism, making the kinetic characteristics of the entire enzymatic hydrolysis process more balanced and controllable. The enzymatic hydrolysis kinetic data in Table 2 confirms this regulatory effect from a process perspective, while the batch stability data of the final product's DE value in Table 1 confirms the superiority of this process from a result perspective. Both together demonstrate that this synergistic process fundamentally solves the technical bottleneck of insufficient precision in controlling the hydrolysis endpoint in the traditional single-enzyme method for preparing low-DE-value maltodextrin, providing a reliable solution for the industrial production of high-quality, high-stability low-DE-value maltodextrin.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A processing technology for low DE value maltodextrin, characterized in that, Includes the following steps: S1. Adjust and balance the moisture content of the starch to 18%-22% (w / w); S2. The starch processed in step S1 is treated in a saturated steam environment at 105℃-110℃ for 15-30 seconds to form a gelatinized layer on the surface of the starch, and then cooled for later use. S3. Disperse the surface-gelatinized starch in water to prepare a suspension with a concentration of 20%-30% (w / w); S4. The suspension is subjected to pulsed electric field treatment under the conditions of electric field strength of 25-35kV / cm, pulse number of 80-150, and system temperature of 25-45℃. S5. The suspension treated with pulsed electric field is subjected to enzymatic hydrolysis. After the reaction is completed, the enzyme is inactivated, filtered, concentrated and dried to obtain the low DE value maltodextrin.

2. The processing technology for low DE value maltodextrin according to claim 1, characterized in that, In step S4, the waveform of the pulsed electric field is a square wave.

3. The processing technology for low DE value maltodextrin according to claim 1, characterized in that, In step S4, the width of a single pulse in the pulsed electric field is 10-30 μs.

4. The processing technology for low DE value maltodextrin according to claim 1, characterized in that, In step S4, the suspension passes through the pulsed electric field treatment area in a laminar flow state, and the flow rate of the suspension is 5-10 L / min.

5. The processing technology for low DE value maltodextrin according to claim 1, characterized in that, In step S5, the enzymatic hydrolysis reaction is carried out using medium-temperature α-amylase.

6. The processing technology for low DE value maltodextrin according to claim 5, characterized in that, In step S5, the temperature of the suspension is adjusted to 60℃-65℃ and the pH of the suspension is adjusted to 6.0-6.5 before the enzymatic hydrolysis reaction.

7. The processing technology for low DE value maltodextrin according to claim 5, characterized in that, In step S5, the amount of medium-temperature α-amylase added is 150-300 U / g dry starch.

8. The processing technology for low DE value maltodextrin according to claim 7, characterized in that, In step S5, the enzymatic hydrolysis time is 30-40 minutes.

9. The processing technology for low DE value maltodextrin according to claim 1, characterized in that, The starch is selected from at least one of corn starch, tapioca starch, potato starch, and wheat starch.

10. A low DE value maltodextrin product, characterized in that, It is prepared by any one of the processing techniques described in claims 1-9.

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