Efficient buckwheat thick slurry preparation method

Abstract

The invention provides an efficient buckwheat thick slurry preparation method which comprises the following steps: dispersing one or more of high-temperature-resistant alpha-amylase, medium-temperature alpha-amylase and saccharifying enzyme in water to prepare enzymatic hydrolysate; performing twin-screw extrusion on the enzymatic hydrolysate and the sieved buckwheat flour to obtain coarse buckwheat pulp; and grinding, centrifuging, homogenizing, sterilizing and filling the coarse buckwheat pulp colloid to obtain the dense buckwheat pulp. According to the preparation method, an extrusion technology and an enzymolysis technology are combined, the effect of enzyme on a substrate is enhanced through extrusion, enzyme activation is induced, the utilization rate of the enzyme is increased, the cost is reduced, and the stability, the sweetness, the liquefaction degree and the taste of the buckwheat pulp are remarkably improved; the double-screw extrusion technology is adopted, the process is simple, time and labor are saved, energy is saved, and continuous and efficient production of the buckwheat thick slurry is achieved; different types of enzyme preparations are compounded, so that the stability and sensory performance of the buckwheat thick slurry are remarkably improved, the content of reducing sugar in the thick slurry is remarkably increased, and the sweetness of the thick slurry is improved.

Description

Technical Field

[0001] The invention relates to the technical field of efficient biological conversion in food processing, and in particular to a method for preparing an efficient buckwheat concentrated slurry. Background Art

[0002] Buckwheat seeds are rich in essential amino acids such as lysine and arginine, and are a high-quality source of plant protein. Buckwheat protein has a high bioavailability and is a good choice to replace animal protein. In addition, buckwheat is also rich in dietary fiber, B vitamins (such as niacin and folic acid), minerals (such as magnesium, manganese, phosphorus, zinc) and a variety of antioxidants (such as rutin, quercetin, vitamin E), etc., so it has the functional properties of lowering blood sugar, lowering blood lipids, anti-oxidation, and promoting digestive health. Buckwheat's low fat and gluten-free properties also make it an ideal food for people with gluten intolerance.

[0003] Buckwheat slurry is a beverage or basic ingredient with buckwheat as the main raw material, with a strong buckwheat flavor and unique taste, retaining a variety of nutrients in buckwheat, and possessing the beneficial functional characteristics of buckwheat. Buckwheat slurry can be drunk directly, and can also be used as a basic ingredient for cooking and baking, such as making buckwheat tofu, buckwheat cakes or as a soup base, etc., showing broad application prospects in the fields of food, medicine and health products. CN108041369A discloses a method for preparing buckwheat slurry by fumigating buckwheat, mixing it with water, and beating it. The buckwheat slurry obtained by this method has poor suspension stability, long-term stratification, insufficient liquefaction, thin taste, and is not conducive to human digestion and absorption. The stability and taste problems can be improved by adding stabilizers and thickeners, which will lead to increased costs and food safety risks. CN103040061A discloses a method for preparing buckwheat juice by short-term puffing of buckwheat grains at high temperature, enzymolysis of cellulose, enzymolysis of high-temperature resistant α-amylase, and sterilization. This method is lengthy, consumes a lot of energy, and has harsh enzymatic hydrolysis conditions. The buckwheat flavor is not strong enough and the sweetness is insufficient. Summary of the invention

[0004]

Technical issues

[0005] The existing buckwheat pulp preparation method has the problems of lengthy process, poor stability, harsh enzymatic hydrolysis conditions, high cost, etc. The buckwheat pulp produced has insufficient buckwheat flavor, insufficient sweetness, is not conducive to digestion and absorption, and has food safety risks. A buckwheat pulp preparation method with safe raw materials, simple process, efficient production and low cost is needed to improve the stability, sweetness, liquefaction and taste of buckwheat pulp.

[0006]

Technical solution

[0007] To solve the above problems, the present invention provides an efficient method for preparing buckwheat pulp by enzyme extrusion. Enzyme extrusion is to use an extruder as an enzyme-catalyzed bioreactor, introduce exogenous enzyme preparations during the extrusion process, and use extrusion to strengthen the effect of the enzyme on the substrate. During the enzyme extrusion process, the enzyme acts on the substrate in a center-to-outward radiating path, and mechanical effects such as screw shearing and pressure induce enzyme activation, showing high-efficiency activity. Extrusion is a high-temperature, short-time, continuous, multifunctional thermomechanical technology that integrates multiple operating units such as material mixing, stirring, shearing, heating, cooking, and molding, and can achieve sustained high productivity. Combining extrusion technology with enzymolysis technology improves the utilization rate of the enzyme, increases the solid content of buckwheat slurry, increases the reducing sugar content and DE value, improves the sensory score, and improves stability.

[0008] The first object of the present invention is to provide an efficient method for preparing buckwheat slurry, comprising the steps of:

[0009] S1. dispersing the enzyme preparation in purified water to obtain an enzymatic solution, wherein the enzyme preparation is one or more of a thermostable α-amylase, a mesophilic α-amylase, and a saccharifying enzyme;

[0010] S2. The enzymatic hydrolysate and the sieved buckwheat flour are subjected to twin-screw extrusion to obtain buckwheat crude slurry; the amount of enzyme preparation added to the enzymatic hydrolysate is 1‰ to 10‰ of the mass of the buckwheat flour;

[0011] S3. Grind, centrifuge, homogenize, sterilize and fill the buckwheat pulp colloid to obtain buckwheat concentrated pulp.

[0012] In one embodiment of the present invention, in step S1, the enzyme activity of the thermostable α-amylase is 50-200 KUN / mL, the enzyme activity of the mesophilic α-amylase is 400-600 KNU / g, and the enzyme activity of the saccharifying enzyme is 200-400 AGU / g.

[0013] In one embodiment of the present invention, in step S2, buckwheat flour is passed through a 40-80 mesh sieve.

[0014] In one embodiment of the present invention, in step S2, the extrusion temperature of the twin-screw extrusion is 50-130°C, the solid feed rate is 3-20kg / h, the liquid feed rate is 5-35L / h, and the screw speed is 80-300r / min.

[0015] In one embodiment of the present invention, in step S2, the six regions of the extrusion cavity are divided into: regions I to V are extrusion enzymatic hydrolysis regions, and region VI is a high-temperature enzyme inactivation region. The high-temperature enzyme inactivation region has both extrusion enzymatic hydrolysis and enzyme inactivation functions.

[0016] In one embodiment of the present invention, in step S2, the temperature of each zone of the extrusion cavity is: 50-80°C in zone I, 60-85°C in zone II, 65-90°C in zone III, 70-100°C in zone IV, 80-110°C in zone V, and 90-130°C in zone VI.

[0017] In one embodiment of the present invention, in step S1, the enzyme preparation is medium-temperature α-amylase; in step S2, the amount of medium-temperature α-amylase added to the enzymatic solution is 1‰ to 10‰ of the mass of buckwheat flour, and the temperature of zones Ⅰ to Ⅵ of the twin-screw extruder is 60 to 130°C.

[0018] In one embodiment of the present invention, in step S1, the enzyme preparations are medium-temperature α-amylase and saccharifying enzyme; in step S2, in the enzymatic hydrolyzate, the amount of medium-temperature α-amylase added is 1‰ to 6‰ of the mass of buckwheat flour, the amount of saccharifying enzyme added is 1‰ to 4‰ of the mass of buckwheat flour, and the temperature of zones Ⅰ to Ⅵ of the twin-screw extruder is 50 to 130°C.

[0019] In one embodiment of the present invention, in step S1, the enzyme preparation is a medium-temperature α-amylase and a high-temperature α-amylase; in step S2, in the enzymatic hydrolyzate, the amount of the medium-temperature α-amylase added is 1‰ to 4‰ of the mass of buckwheat flour, and the amount of the high-temperature α-amylase added is 1‰ to 6‰ of the mass of buckwheat flour, and the temperature of zones Ⅰ to Ⅵ of the twin-screw extruder is 65 to 130°C.

[0020] In one embodiment of the present invention, in step S1, the enzyme preparation is a medium-temperature α-amylase and a high-temperature α-amylase; in step S2, in the enzymatic hydrolyzate, the amount of the high-temperature α-amylase added is 1‰ to 6‰ of the mass of buckwheat flour, the amount of the medium-temperature α-amylase added is 1‰ to 2‰ of the mass of buckwheat flour, and the temperature of the I to VI zones of the twin-screw extruder is 65 to 130°C; after completing step S2, the saccharifying enzyme is added to the buckwheat pulp in an amount of 0.1‰ to 2‰ of the solid mass of the buckwheat pulp, and the residual temperature after extrusion is used for enzymolysis for 0 to 2h, and then step S3 is performed. The reason is that the optimal enzymatic hydrolysis temperature of the saccharifying enzyme is mutually exclusive with the high-temperature α-amylase, and the simultaneous addition will lead to the inactivation of the saccharifying enzyme.

[0021] In one embodiment of the present invention, in step S3, the grinding fineness of the colloid mill is 200-300 meshes, and the grinding time is 0.5-2 min.

[0022] In one embodiment of the present invention, in step S3, the centrifugal process speed is 2000-3000 r / min, and the centrifugal time is 1-5 min.

[0023] In one embodiment of the present invention, in step S3, the homogenization process pressure is 30-60 MPa, the homogenization times are 1-2 times, and each time is 5-60 seconds.

[0024] In one embodiment of the present invention, in step S3, the sterilization temperature is 105-135° C., and the sterilization time is 5-60 seconds.

[0025] The second object of the present invention is to provide buckwheat slurry prepared by the buckwheat slurry preparation method.

[0026] In one embodiment of the present invention, the solid content of the buckwheat slurry is 30-60%.

[0027] Solid content refers to the percentage of the mass of the solid part remaining after removing water from buckwheat concentrate to the total mass of buckwheat concentrate, including soluble solids and insoluble solids.

[0028] The third object of the present invention is to provide the use of the buckwheat slurry in food or beverage.

[0029]

Beneficial Effects

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) Combining extrusion technology with enzymatic hydrolysis technology, using extrusion to strengthen the effect of enzymes on substrates, induce enzyme activation, and improve enzyme utilization, which is conducive to reducing costs and significantly improving the stability, sweetness, liquefaction and taste of buckwheat pulp.

[0032] (2) The twin-screw extrusion technology is used, which has a simple process, saves time, labor and energy, and realizes the continuous and efficient production of buckwheat slurry.

[0033] (3) Compounding different types of enzyme preparations significantly improved the stability and sensory properties of buckwheat concentrate, significantly increased the reducing sugar content in the concentrate, and improved the sweetness of the concentrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is the reducing sugar standard curve;

[0035] Figure 2 The present invention is a schematic diagram of the process for preparing buckwheat slurry. DETAILED DESCRIPTION

[0036] Test Method

[0037] Solid content: The moisture content of buckwheat slurry was determined by the first method direct drying method according to the national standard GB 5009.3-2016 to obtain its solid content.

[0038] Reducing sugar content:

[0039] First, prepare a glucose standard solution with a concentration of 1 mg / mL. Take 0, 0.2, 0.4, 0.6, 0.8, and 1.0 mL of the glucose standard solution in a centrifuge tube, add deionized water to 1.0 mL, accurately add 1.5 mL of DNS color developer, heat in a boiling water bath for 5 min, and then quickly cool to room temperature. Accurately add 1.5 mL of deionized water to dilute and mix, measure the absorbance at a wavelength of 540 nm, and draw a standard curve, such as Figure 1 shown.

[0040] Secondly, take 1.0g sample, add 20mL deionized water, vortex for 1min, centrifuge at 8000g for 10min, separate the supernatant; take the precipitate, add 20mL deionized water, centrifuge at 8000g for 10min, combine the two supernatants, and make up to volume in a 100mL volumetric flask for later use. Take 200μL of the fixed-volume supernatant in a 2ml centrifuge tube, add 200μL deionized water and 300μL DNS colorimetric agent, boil in a water bath for 5min and quickly cool to room temperature, add 300μL deionized water again, mix well, and color at a wavelength of 540nm on an ELISA reader to read the absorbance; finally, use the standard curve to calculate the reducing sugar content of the sample.

[0041] DE value: The percentage of reducing sugar content (calculated as glucose) in the sample to dry matter is called DE value. The calculation formula of DE value is as follows:

[0042] DE value = (reducing sugar content%) / (dry matter content%) × 100%

[0043] Among them, dry matter refers to the mass of solid matter remaining after the sample is dried and all water is removed.

[0044] Sensory evaluation: 50 test volunteers were invited to evaluate the appearance, flavor, taste, etc. of the buckwheat syrup. The specific evaluation method is shown in Table 1. A total of 48 valid results were collected.

[0045] Table 1 Sensory evaluation scoring rules

[0046]

[0047] Except for sensory evaluation, all experiments were repeated three times, and the results were expressed as mean ± standard deviation. SPSS25.0 software was used to analyze the data with one-way analysis of variance and Duncan test, and p < 0.05 was considered statistically significant.

[0048] Raw materials: The enzyme preparations used in the examples and comparative examples were purchased from Beijing Novozymes Co., Ltd. The activity of the medium-temperature α-amylase was 480 KUN / g, the activity of the high-temperature α-amylase was 120 KUN / mL, and the activity of the saccharifying enzyme was 300 AGU / g.

[0049] Example 1

[0050] An efficient method for preparing buckwheat slurry comprises the following steps:

[0051] S1. dispersing the medium temperature α-amylase in purified water to obtain an enzymatic solution;

[0052] S2. After cleaning the buckwheat, place it in a grinder and grind it into buckwheat flour so that all the buckwheat flour can pass through a 60-mesh screen; put the enzymatic solution into the liquid feeder of the twin-screw extruder, put the sieved buckwheat flour into the silo of the twin-screw extruder, and add the medium-temperature α-amylase in the enzymatic solution at a rate of 5‰ of the mass of the buckwheat flour; perform twin-screw extrusion, the temperatures of the twin-screw extruder zones Ⅰ to Ⅵ are 70°C, 75°C, 80°C, 85°C, 90°C, and 95°C, respectively, the solid feed rate is 5kg / h, the liquid feed rate is 8L / h, and the screw speed is 150r / min to obtain buckwheat pulp;

[0053] S3. Grind the buckwheat pulp colloid to a fineness of 290 mesh and a grinding time of 1 min. Centrifuge it at 2800 r / min for 3 min using a horizontal screw centrifuge. Then homogenize it once at 40 MPa for 30 s each time. Sterilize it at 115°C for 60 s and perform aseptic cold filling to obtain buckwheat concentrated pulp.

[0054] Example 2

[0055] An efficient method for preparing buckwheat slurry comprises the following steps:

[0056] S1. Dispersing the medium temperature α-amylase and saccharifying enzyme in purified water to prepare an enzymatic solution;

[0057] S2. After cleaning the buckwheat, place it in a grinder and grind it into buckwheat flour so that all the buckwheat flour can pass through a 60-mesh screen; put the enzymatic solution into the liquid feeder of the twin-screw extruder, put the sieved buckwheat flour into the silo of the twin-screw extruder, add 3‰ of the mass of the buckwheat flour to the enzymatic solution, and add 2‰ of the mass of the buckwheat flour to the saccharifying enzyme; perform twin-screw extrusion, the temperatures of the twin-screw extruder zones Ⅰ to Ⅵ are 60°C, 65°C, 70°C, 75°C, 85°C, and 95°C, respectively, the solid feed rate is 5kg / h, the liquid feed rate is 8L / h, and the screw speed is 150r / min to obtain buckwheat coarse pulp;

[0058] S3. Grind the buckwheat pulp colloid to a fineness of 290 mesh and a grinding time of 1 min. Centrifuge it at 2800 r / min for 3 min using a horizontal screw centrifuge. Then homogenize it once at 40 MPa for 30 s each time. Sterilize it at 115°C for 60 s and perform aseptic cold filling to obtain buckwheat concentrated pulp.

[0059] Example 3

[0060] An efficient method for preparing buckwheat slurry comprises the following steps:

[0061] S1. Dispersing the medium temperature α-amylase and the high temperature resistant α-amylase in purified water to prepare an enzymatic solution;

[0062] S2. After cleaning the buckwheat, place it in a grinder and grind it into buckwheat flour so that all the buckwheat flour can pass through a 60-mesh screen; put the enzymatic solution into the liquid feeder of the twin-screw extruder, put the sieved buckwheat flour into the silo of the twin-screw extruder, add 2‰ of the mass of the buckwheat flour to the enzymatic solution, and add 3‰ of the mass of the buckwheat flour to the high-temperature α-amylase; perform twin-screw extrusion, the temperatures of the twin-screw extruder zones Ⅰ to Ⅵ are 70°C, 80°C, 85°C, 95°C, 105°C, and 115°C, respectively, the solid feed rate is 5kg / h, the liquid feed rate is 8L / h, and the screw speed is 150r / min to obtain buckwheat coarse pulp;

[0063] S3. Grind the buckwheat pulp colloid to a fineness of 290 mesh and a grinding time of 1 min. Centrifuge it at 2800 r / min for 3 min using a horizontal screw centrifuge. Then homogenize it once at 40 MPa for 30 s each time. Sterilize it at 115°C for 60 s and perform aseptic cold filling to obtain buckwheat concentrated pulp.

[0064] Example 4

[0065] An efficient method for preparing buckwheat slurry comprises the following steps:

[0066] S1. Dispersing the medium temperature α-amylase and the high temperature resistant α-amylase in purified water to prepare an enzymatic solution;

[0067] S2. After cleaning the buckwheat, place it in a grinder and grind it into buckwheat flour so that all the buckwheat flour can pass through a 60-mesh screen; put the enzymatic solution into the liquid feeder of the twin-screw extruder, put the sieved buckwheat flour into the enzymatic solution in the silo of the twin-screw extruder, add 1‰ of the mass of the buckwheat flour at a medium-temperature α-amylase, and add 3‰ of the mass of the buckwheat flour at a high-temperature α-amylase; perform twin-screw extrusion, the temperatures of the twin-screw extruder zones Ⅰ to Ⅵ are 70°C, 80°C, 85°C, 95°C, 105°C, and 115°C, respectively, the solid feed rate is 5kg / h, the liquid feed rate is 8L / h, and the screw speed is 150r / min to obtain buckwheat pulp;

[0068] S3. Grind the buckwheat pulp colloid to a fineness of 290 mesh and a grinding time of 1 min. Centrifuge it at 2800 r / min for 3 min using a horizontal screw centrifuge. Then homogenize it once at 40 MPa for 30 s each time. Sterilize it at 115°C for 60 s and perform aseptic cold filling to obtain buckwheat concentrated pulp.

[0069] Example 5

[0070] An efficient method for preparing buckwheat slurry comprises the following steps:

[0071] S1. Dispersing the medium temperature α-amylase and the high temperature resistant α-amylase in purified water to prepare an enzymatic solution;

[0072] S2. After cleaning the buckwheat, place it in a grinder and grind it into buckwheat flour so that all the buckwheat flour can pass through a 60-mesh screen; put the enzymatic solution into the liquid feeder of the twin-screw extruder, put the sieved buckwheat flour into the silo of the twin-screw extruder, and add 1‰ of the mass of the buckwheat flour to the enzymatic solution at a medium-temperature α-amylase, and 3‰ of the mass of the buckwheat flour at a high-temperature α-amylase; perform twin-screw extrusion, the temperatures of the twin-screw extruder zones Ⅰ to Ⅵ are 70°C, 75°C, 85°C, 95°C, 105°C, and 115°C, respectively, the solid feed rate is 5kg / h, the liquid feed rate is 8L / h, and the screw speed is 150r / min to obtain buckwheat pulp;

[0073] S3. Add 1‰ of solid mass of saccharifying enzyme to the buckwheat pulp, mix well, and use the residual heat of extrusion for 1h to obtain new buckwheat pulp;

[0074] S4. Grind the new buckwheat pulp colloid to a fineness of 290 mesh and a grinding time of 1 min. Centrifuge it at 2800 r / min for 3 min using a horizontal screw centrifuge. Then homogenize it once at 40 MPa for 30 s each time. Sterilize it at 115°C for 60 s and perform aseptic cold filling to obtain buckwheat concentrated pulp.

[0075] Comparative Example 1

[0076] A method for preparing buckwheat thick slurry.

[0077] The difference from Example 2 is that only Zone I, Zone II, Zone III and Zone IV of the twin-screw extruder are used, Zone I to Zone III are extrusion enzymolysis zones, and Zone IV is a high-temperature enzyme inactivation zone. The temperatures of the four zones are 60°C, 70°C, 80°C and 95°C respectively.

[0078] Table 2 Solids, reducing sugar content and DE value of buckwheat pulp

[0079]

[0080] Table 3 Sensory evaluation scores of buckwheat pulp

[0081]

[0082] Table 2 shows the solid content, reducing sugar content and DE value of the buckwheat slurries prepared in Examples 1 to 5.

[0083] Solid content refers to the percentage of the mass of the solid part remaining after removing water from buckwheat pulp to the total mass of buckwheat pulp. This indicator is usually used to measure the proportion of solid matter in liquid or semi-solid samples, and is an important parameter for evaluating food, beverages, etc. The solid content of the buckwheat slurry prepared in Examples 1 to 5 is 38% to 40%, indicating that the extrusion synergistic enzymatic hydrolysis technology can significantly improve the product concentration. Traditional enzymatic hydrolysis technology can only obtain enzymatic products with a solid content of less than 20%. Not only does the enzymatic hydrolysis time take a long time, but a thickener must also be added to increase the product concentration. Compared with traditional enzymatic hydrolysis, the present invention can prepare a high-concentration buckwheat slurry product by one enzymatic hydrolysis without the need for concentration or the addition of a thickener, which provides food safety while also reducing corporate costs and increasing energy efficiency.

[0084] The reducing sugar content is closely related to the enzymatic liquefaction degree of buckwheat slurry and the sweetness of the product. Starch is decomposed into smaller sugar molecules under the action of amylase. Amylase can cut the glycosidic bonds in the starch molecules, gradually degrade and liquefy them into dextrin and maltose, and finally generate glucose. The high reducing sugar content indicates that the higher the sweetness of the buckwheat slurry, the better the enzymatic liquefaction degree. At the same time, the higher the reducing sugar content, the lower the viscosity of the buckwheat slurry after pressurized enzymatic hydrolysis, and the better the stability. The buckwheat slurry prepared in Example 2 has the highest reducing sugar content and has better stability, palatability and sweetness. The reason is that saccharifying enzymes can not only cut off α-1,4 glycosidic bonds, but also α-1,6 glycosidic bonds, so that starch molecules are completely decomposed into single glucose molecules. When saccharifying enzymes are used in combination with α-amylase, α-amylase is responsible for randomly cutting α-1,4 glycosidic bonds in starch molecules to produce short chains of dextrin or maltose, and then saccharifying enzymes break down these short chains into glucose. This can accelerate the complete enzymatic hydrolysis and liquefaction of starch, thereby increasing the reducing sugar content and product sweetness. At the same time, the enzyme action temperature of the enzyme preparation selected in Example 2 is relatively low, which can reduce the production cost of the enterprise to the maximum extent and stabilize the product properties.

[0085] DE value is an important indicator for measuring the reducing sugar content in starch or starch hydrolysate. DE value reflects the degree of starch hydrolysis. The higher the value, the more thorough the starch hydrolysis and the more simple sugars generated. Compared with Examples 1 to 5, the buckwheat slurry obtained after extrusion and enzymatic hydrolysis in Example 2 has a high DE value, indicating that the enzymatic hydrolyzed sample of this scheme has high sweetness, low viscosity, and high starch liquefaction degree.

[0086] Table 3 shows the sensory scores of the buckwheat slurries prepared in Examples 1 to 5. In terms of smell, Examples 1, 3, and 4 have the fragrance of buckwheat, and Examples 2 and 5 have a stronger buckwheat fragrance. In terms of appearance, Examples 1 to 5 all present a uniform and stable appearance without water separation; the color of Examples 1, 2, and 5 is consistent with the color of buckwheat itself, and the color of Examples 3 and 4 is slightly different from buckwheat. In terms of taste, Examples 1, 2, and 5 have a suitable buckwheat fragrance and liquefied sweetness, and the buckwheat fragrance and liquefied sweetness of Examples 3 and 4 are lighter. In terms of taste, Examples 1 to 5 all have a taste with moderate viscosity. Overall, the sensory score of Example 2 is higher, followed by Examples 1 and 5.

[0087] Compared with Comparative Example 1, the reducing sugar content, DE value, sensory score, etc. of Example 2 are better. The reason is that the twin-screw extrusion method of the present invention has multiple extrusion temperature zones, a long extrusion cavity, a large contact area between the enzyme preparation and buckwheat flour, a long action time, and a large number of screw shearing times, which is conducive to the deep liquefaction of starch. The six-zone extrusion enzymolysis temperature is stable, which is conducive to the enzyme preparation to exert the maximum enzymolysis effect, reduce the type of enzymes, and centralize the extrusion temperature setting, saving costs, extending the action time of related enzymes, and improving utilization efficiency, thereby achieving efficient production, and improving the stability, palatability and sensory score of buckwheat slurry, and increasing the application value of buckwheat slurry.

[0088] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. An efficient method for preparing buckwheat slurry, characterized in that: The preparation method comprises the steps of: S1. The enzyme preparation is dispersed in purified water to obtain an enzymatic solution; the enzyme preparation is one or more of a thermostable α-amylase, a mesophilic α-amylase, and a saccharifying enzyme; S2. The enzymatic hydrolysate and the sieved buckwheat flour are subjected to twin-screw extrusion to obtain buckwheat crude slurry; the amount of enzyme preparation added to the enzymatic hydrolysate is 1‰ to 10‰ of the mass of the buckwheat flour; S3. Grind, centrifuge, homogenize, sterilize and fill the buckwheat pulp colloid to obtain buckwheat concentrated pulp.

2. The method for preparing buckwheat slurry according to claim 1, characterized in that: In step S2, buckwheat flour is passed through a 40-80 mesh sieve; the extrusion temperature of the twin-screw extruder is 50-130° C., the solid feeding rate is 3-20 kg / h, the liquid feeding rate is 5-35 L / h, and the screw speed is 80-300 r / min.

3. The method for preparing buckwheat slurry according to claim 1, characterized in that: In step S2, the six areas of the extrusion cavity are divided into: areas I to V are extrusion enzymatic hydrolysis areas, and area VI is a high-temperature enzyme inactivation area; the temperatures of each area of ​​the extrusion cavity are: 50-80°C in area I, 60-85°C in area II, 65-90°C in area III, 70-100°C in area IV, 80-110°C in area V, and 90-130°C in area VI.

4. The method for preparing buckwheat slurry according to claim 1, characterized in that: In step S3, the fineness of the colloid grinding is 200-300 meshes, and the grinding time is 0.5-2 min.

5. The method for preparing buckwheat slurry according to claim 1, characterized in that: In step S3, the centrifugal process speed is 2000-3000 r / min, and the centrifugal time is 1-5 min.

6. The method for preparing buckwheat slurry according to claim 1, characterized in that: In step S3, the homogenization process pressure is 30-60 MPa, the homogenization times are 1-2 times, and each time is 5-60 seconds.

7. The method for preparing buckwheat slurry according to claim 1, characterized in that: In step S3, the sterilization temperature is 105-135° C., and the sterilization time is 5-60 seconds.

8. Buckwheat syrup prepared by the method according to any one of claims 1 to 7.

9. The buckwheat slurry according to claim 8, characterized in that: The solid content is 30-60%.

10. Use of the buckwheat slurry according to claim 9 in food or beverage.

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