Preparation method of starch vermicelli free of thermalization and thickening and product

Abstract

The invention relates to the technical field of food processing, and discloses a preparation method of starch vermicelli free of thermalization and thickening and a product. The preparation method comprises the following steps: sieving starch, and preparing granular cold water swellable starch by adopting a high-temperature and high-pressure reaction or extrusion modification process; the preparation method comprises the following steps: proportionally adding granular cold water swellable starch and untreated starch into a mixer, and uniformly dry-mixing; then adding water and stirring to form uniform and non-caking plastic starch dough; extruding the starch dough to prepare vermicelli / vermicelli; freezing, aging and drying the vermicelli / vermicelli, cooling to room temperature, and packaging to obtain the finished product vermicelli / vermicelli. By adopting the preparation method to prepare the vermicelli / vermicelli, the step of independent hot gelatinization and thickening in the traditional process is omitted, the energy consumption is reduced, meanwhile, the gel strength and the elongation at break of the vermicelli / vermicelli are improved, the cooking loss and the vermicelli breaking rate are reduced, and the problems that the traditional vermicelli / vermicelli is easy to break and slightly hard in mouth feel are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of food processing, in particular to a starch noodle and vermicelli preparation method and product without heat gelatinization. BACKGROUND

[0002] As a traditional starch food, vermicelli / noodle has a high demand in the domestic and foreign markets due to its unique taste and rich eating methods. In the traditional vermicelli / noodle production process, "gelling" is a key link that determines the quality of the product. The core principle of gelling is to prepare starch paste from part of the original starch by heat gelatinization, and then mix the paste with the remaining original starch and water to form a starch dough with good plasticity and cohesiveness. The final product is obtained through subsequent processes such as extrusion molding or powder leakage molding, cooking, cooling, and drying.

[0003] However, the traditional process has the following significant defects: High energy consumption and long working hours: traditional gelling requires separate heating and gelatinization of part of the original starch. This process not only consumes a large amount of heat energy (such as steam and electricity), but also requires additional stirring and insulation equipment and operating time, resulting in reduced production efficiency and increased production costs. Poor product quality stability: the heat gelatinization process has strict requirements for temperature, time, and stirring rate. If the parameters are not properly controlled, it is easy to cause over-gelatinization of starch (resulting in high viscosity of the dough, making it difficult to form) or insufficient gelatinization (resulting in insufficient cohesiveness of the dough, which is prone to breaking during cooking), thereby affecting the gel quality, tensile properties, and cooking stability of the vermicelli / noodle. Poor cooking performance and sensory quality: the vermicelli / noodle prepared by the traditional process generally has high cooking loss rate (high starch dissolution, turbid soup), high breaking rate (prone to breaking during cooking), low brightness and whiteness (starch is prone to slight browning during heat gelatinization), and long cooking time (requires long heating time to achieve the desired taste), which cannot meet the needs of consumers for high-quality vermicelli / noodle.

[0004] To solve the above technical problems, the present application is proposed. SUMMARY

[0005] To solve the above technical problems, the present application proposes using granular cold-water-swellable starch instead of traditional heat-gelatinized starch as a gelling agent to develop a vermicelli / noodle preparation process without heat gelatinization, aiming to fundamentally solve the technical problems of the traditional process and significantly improve the product quality.

[0006] The application provides a starch noodle preparation method and product without heat gelatinization and thickening, and the preparation method omits the step of heat gelatinization and thickening in the traditional process, reduces energy consumption, improves the gel strength and elongation at break of the noodle / vermicelli, reduces the cooking loss and broken noodle rate, and solves the problems of easy brittle breakage and hard taste of the traditional noodle / vermicelli.

[0007] To achieve the above-mentioned purpose, the application provides a starch noodle preparation method without heat gelatinization and thickening, comprising the following steps: Step 1, preparing granular cold-water-swellable starch: selecting one or several mixed starches from potato starch, mung bean starch, cassava starch and corn starch, passing through an 80-120 mesh sieve, and preparing granular cold-water-swellable starch by high-temperature high-pressure reaction or extrusion modification process; Step 2, preparing noodle / vermicelli starch dough: adding the granular cold-water-swellable starch and untreated starch into a mixer according to a specific mass ratio, dry mixing for 3-10 min to mix uniformly, then slowly adding water and continuing to stir for 5-25 min, without heating in the stirring process, and controlling the ambient temperature at 20-30 DEG C, to form a uniform, lump-free and plastic starch dough; Step 3, producing noodle / vermicelli without heat gelatinization and thickening: sending the starch dough into a single-screw temperature-controllable self-cooked rice noodle machine for extrusion to prepare noodle / vermicelli, freezing, aging, drying and cooling the noodle / vermicelli to room temperature, packaging, and obtaining finished noodle / vermicelli.

[0008] Further, in step 1, the specific steps of preparing granular cold-water-swellable starch by high-temperature high-pressure reaction are as follows: 1) weighing the raw starch and placing it in a container, adding a mixed solution of ethanol and water, and stirring to obtain a uniform starch suspension; 2) placing the starch suspension into a high-temperature high-pressure microreactor for reaction; 3) when the temperature reaches 110-160 DEG C, keeping the temperature for 5-30 min, taking out the starch solution after cooling to room temperature, vacuum filtering and washing with ethanol, drying in an oven, grinding with a flour mill after drying, passing through a 60-120 mesh sieve, sealing in a self-sealing bag and storing in a desiccator for standby.

[0009] Further, in step 1), the mass fraction of the ethanol solution is 50%-80%, and the mass ratio of the starch to the ethanol solution is 1:2-1:8; in step 3), the oven drying temperature is 90-120 DEG C, and the drying time is 10-60 min.

[0010] Further, in step 2), the high-temperature and high-pressure micro-reactor has the following conditions: the reaction temperature is 85-160 ℃, the stirring speed is 200-600 r / min, the reaction pressure is 0.2-0.7 MPa, and the reaction time is 0.5-2 h.

[0011] Further, in step 1), the specific steps for preparing the granular cold-water-swellable starch by the extrusion modification process are as follows: 1) Weigh the starch and place it in a container, and then add the ethanol solution and stir uniformly to obtain a starch dough; 2) The starch dough is sent into an extruder for high-temperature extrusion and gelatinization molding to obtain a long strip-shaped starch extrudate; 3) The strip-shaped extrudate is placed in a forced air oven for drying treatment, the drying temperature is 90-120 ℃, the drying time is 10-60 min, and after drying, the extrudate is crushed at low temperature, sieved through a 60-120 mesh sieve, sealed in a self-sealing bag and stored in a desiccator for standby.

[0012] Further, in step 1), the concentration of the ethanol solution is 30%-90%, the mass ratio of the starch to the ethanol is 1:0.1-1.5, and the concentration of the starch is 40%-90%.

[0013] Further, in step 2), during the high-temperature extrusion and gelatinization molding, the gelatinization temperature is 60-130 ℃, the molding zone temperature is fixed at 45-70 ℃, and the rotation speed is 50-200 r / min.

[0014] Further, in step 2), the mass ratio of the granular cold-water-swellable starch to the untreated starch is 0.03-0.2:1, and the water content of the starch dough is 40%-65%.

[0015] Further, in step 3), the extrusion temperature of the self-matured rice flour machine is 80-95 ℃, the degree of maturation is 75%-95%, the extrusion pressure is 0.5-1.5 MPa, the die hole diameter is 1.2-2.2 mm, the freezing temperature is -18--30 ℃, the time is 3-12 h, the aging temperature is 0-10 ℃, the time is 8-24 h, the oven drying temperature is 40-60 ℃, the time is 4-8 h, and the water content of the vermicelli / noodle is ≤14%.

[0016] Further, the application also provides a starch vermicelli / noodle for heat-free seasoning, which is prepared by the above preparation method.

[0017] The starch vermicelli / noodle for heat-free seasoning prepared by the preparation method has the following advantages and positive effects: 1. The present application directly replaces the traditional process of separately hot gelatinized raw starch with granular cold water-swellable starch to thicken, completely eliminating the energy consumption of steam, electricity and other energy required for heating and gelatinizing raw starch, compared with the traditional process, it can reduce the energy consumption of hot gelatinization link by 10%-30%, greatly reduce the energy cost in the production process of vermicelli / noodle, and meet the green and low-carbon industrial development trend.

[0018] 2. The gel quality and tensile properties of the vermicelli / noodle prepared by the present application are significantly improved, based on the special structure and cold water swelling properties of granular cold water-swellable starch, it can be uniformly dispersed and form a more stable three-dimensional network structure during the preparation of the noodle, compared with the products produced by the traditional hot gelatinization thickening process, the gel strength of the product of the present application is improved from 0.252 MP to 0.574 MP, and the elongation at break is improved from 231.3% to 437.5%, effectively solving the problems of easy brittle fracture and hard taste of traditional vermicelli / noodle, and the product has more elasticity and smoothness when eaten, and can still maintain good gel stability after cold storage or reheating, reducing the taste deterioration.

[0019] 3. The cooking loss and broken rate of the vermicelli / noodle prepared by the present application are significantly reduced, improving the product qualification rate and cooking resistance; granular cold water-swellable starch and raw starch have good compatibility, and the two form a dense structural barrier inside the vermicelli / noodle, reducing the dissolution and loss of starch during cooking.

[0020] The technical solutions of the present application will be further described in detail below by means of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Strain-stress test results of the vermicelli / noodle prepared in examples 1-3 and comparative examples 1-2 of the present application; Figure 2 Strain-stress test results of the vermicelli / noodle prepared in examples 2, 4-6 and comparative examples 3-4 of the present application; Figure 3 Optical micrographs of different natural starches and granular cold water-swellable starches in examples 2, 4-6 of the present application, wherein M: corn starch, Po: potato starch, T: cassava starch, Mb: mung bean starch; Native: raw starch, VGS: granular cold water-swellable starch; Figure 4 Particle morphology analysis results of different natural starches and granular cold water-swellable starches in examples 2, 4-6 of the present application, wherein M: corn starch, Po: potato starch, T: cassava starch, Mb: mung bean starch; VGS: granular cold water-swellable starch. DETAILED DESCRIPTION

[0022] The technical solutions of the present application are further described below with reference to the drawings and examples.

[0023] Unless otherwise defined, the technical terms or scientific terms used in the present application shall have the usual meanings understood by those with ordinary skills in the art to which the present application pertains.

[0024] Based on the examples in the present application, all other examples obtained by those with ordinary skills in the art without making creative efforts shall fall within the scope of protection of the present application. The experimental methods not specified in the following examples are generally determined according to national standards. The experimental instruments, equipment and reagents not specified in the following examples are all commercially available raw materials.

[0025] Unless otherwise defined or explained, all professional and scientific terms used in the present application have the same meanings as those familiar to those with ordinary skills in the art. In addition, any methods and materials similar or equivalent to those described can be applied in the present application.

[0026] The present application overcomes the defects of the "hot gelatinization and thickening" link in the traditional starch-based vermicelli / noodle preparation process, and provides a starch-based vermicelli / noodle preparation process without hot gelatinization and thickening. By replacing the traditional hot gelatinized starch with granular cold water-swellable starch as the thickening component, the technical effects of saving the hot gelatinization link, reducing energy consumption and working hours, and significantly improving the gel quality and stretchability of vermicelli / noodles are achieved.

[0027] Specifically, the starch-based vermicelli / noodle preparation method without hot gelatinization and thickening comprises the following steps: Step 1: Preparation of granular cold water-swellable starch: (1) Raw starch: select one or more mixed starches from potato starch, mung bean starch, cassava starch, corn starch and other raw starches, pass through an 80-120 mesh sieve, and prepare granular cold water-swellable starch by high temperature and high pressure reaction or extrusion modification process (only one of the two can be selected); A. High temperature and high pressure reaction process: 1) A certain amount of raw starch is placed in a container and a mixed solution of ethanol and water is added, the mass fraction of ethanol solution is 50%-80%, and the mass ratio of starch to ethanol solution is 1:2-8, and the starch is stirred to obtain a uniform starch dough; it should be noted that the mass ratio of starch to ethanol solution can be 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8; 2) Put the prepared starch dough into a high temperature and high pressure microreactor, set the reaction temperature to 85-160℃, the stirring speed to 200-600 r / min, the reaction pressure to 0.2-0.7 MPa, and the reaction time to 0.5-2 h; 3) After the temperature reaches the set value (110-160℃), keep it for 5-30 min, take out the starch solution after cooling to room temperature, vacuum filtration combined with ethanol washing 2-4 times, oven drying temperature is 90-120℃, drying time is 10-60 min, after drying, use a flour mill to grind, sieve (60-120 mesh), put into a self-sealing bag, seal and store in a dry dish, ready for use.

[0028] B. Extrusion pasting forming process: 1) A certain amount of starch is weighed and placed in a container, and ethanol solution (30%-90%) is added, the mass ratio of starch to ethanol is 1:0.1-1.5, and the starch dough (40%-90%) is obtained after stirring uniformly; 2) The starch dough is sent into an extruder for high-temperature extrusion pasting forming (pasting temperature is 60-130℃, forming zone temperature is fixed at 45-70℃, rotation speed is 50-200 r / min), and a long strip of starch extrudate is obtained; 3) The strip-shaped extrudate is placed in a forced air oven for drying treatment, the drying temperature is 90-120℃, the drying time is 10-60 min, after drying, low-temperature crushing is carried out, sieving (60-120 mesh), put into a self-sealing bag, seal and store in a dry dish, ready for use.

[0029] Step 2, preparation of vermicelli / starch dough: The granular cold-water-swellable starch prepared in step 1 and its original starch (or other types of original starch) are added to a mixer according to different mass ratios (0.03-0.2:0.8-0.97), dry mixing for 3-10 min until uniform mixing; then a certain amount of water is slowly added, and stirring is continued for 5-25 min, without heating during the stirring process, and the environmental temperature is controlled at 20-30℃, forming a uniform, lump-free, and plastic starch dough (water content 40%-65%). It should be noted that the mass ratio of granular cold-water-swellable starch to its original starch (or other types of original starch) is 0.03-0.2:0.8-0.97, that is, the content of granular cold-water-swellable starch can be 3%, 5%, 8%, 10%, 12%, 15%, 18%, or 20%.

[0030] Step 3, production of heat-free pasting starch vermicelli: The starch dough prepared in step 2 is sent to a single-screw temperature-controllable self-cooked rice flour machine (extrusion temperature is controlled at 80-95 DEG C, cooking degree is 75%-95%, extrusion pressure is 0.5-1.5 MPa, and die hole diameter is 1.2-2.2 mm) to prepare vermicelli / noodle by extrusion; the vermicelli / noodle (water content is 35%-60%) is subjected to freezing (-18~-30 DEG C, time is 3-12 h), aging (temperature is 0-10 DEG C, time is 8-24 h), drying (drying in an oven at 40-60 DEG C for 4-8 h, and water content is less than or equal to 14%), cooling to room temperature, packaging, and vermicelli / noodle is obtained.

[0031] The present application aims at the technical pain point that part of the original starch needs to be heated and gelatinized separately to prepare the sauce in the traditional starch-based vermicelli / noodle production process, and innovatively uses the granular cold-water swellable starch (covering the physical modification products of various starches such as potato, mung bean, cassava, wheat and corn) prepared in the preliminary experiment to replace the traditional heat-gelatinized starch as the sauce ingredient, which is directly mixed with the original starch and water to prepare the starch dough, and then the vermicelli / noodle production is completed by extrusion or powder leakage process. This scheme not only completely eliminates the separate starch heat-gelatinization sauce link in the traditional process, but also realizes the dual breakthrough of production efficiency and product quality through the unique performance of the granular cold-water swellable starch, and solves the technical problems of high energy consumption, long working hours and unstable product quality in the traditional process.

[0032] The technical scheme has the following technical effects: I. Process innovation level: break through the traditional heat-gelatinization bottleneck and realize efficient production process: 1) The present application directly replaces the original starch sauce in the traditional process which needs to be heated and gelatinized separately with the granular cold-water swellable starch (covering starches such as potato, mung bean, cassava and corn), which completely eliminates the energy consumption of steam, electricity and other energy sources required for heating and gelatinization of the original starch. Compared with the traditional process, the present process can reduce the energy consumption related to heat-gelatinization by 10%-30%, greatly reduce the energy cost in the production process of vermicelli / noodle, and meet the green and low-carbon industrial development trend.

[0033] 2) Shorten the production time, improve the production efficiency, in the traditional process, the original starch heat-gelatinization needs to go through heating, insulation, cooling and other steps, which takes a long time, and the single heat-gelatinization treatment usually takes 30-50 min, and the starch paste needs to be cooled to an appropriate temperature before mixing with the original starch; in the present application, the granular cold-water swellable starch can be directly mixed with the original starch and water without additional heating treatment, the time for mixing and preparing the dough can be shortened to 5-10 min, the overall production cycle is shortened by 25%-40%, the investment and maintenance cost of temperature control equipment is reduced, and the continuous operation capacity of the production line is improved.

[0034] II. Product quality level: comprehensive optimization of starch-based vermicelli / vermicelli core quality indicators: 1) Significantly improve gel quality and tensile properties. The special structure and cold water swelling properties of the granular cold water-swellable starch can be uniformly dispersed and form a more stable three-dimensional network structure during noodle preparation. Compared with products produced by traditional hot paste-making process, the gel strength of the product is increased from 0.252 MP to 0.574 MP, and the elongation at break is increased from 231.3% to 437.5%. This effectively solves the problem of brittle fracture and hard texture of traditional vermicelli / vermicelli, and the product has better elasticity and smoothness when eaten. It can still maintain good gel stability after cold storage or reheating, reducing the deterioration of taste.

[0035] 2) Reduce cooking loss and broken noodle rate, improve product pass rate and cooking resistance; The compatibility of granular cold water-swellable starch and raw starch is better, which can form a dense structural barrier inside the vermicelli / vermicelli, reducing the dissolution and loss of starch during cooking. The broken noodle rate of the product is reduced from 10%-15% of the traditional process to 5%, while the water absorption is increased from 130.29% to 195.68%. The cooking time of the product is effectively shortened by 4 min (from 14 min 36 s to 10 min 35 s), and there is no need for advance soaking, which significantly improves the convenience of eating and adapts to the needs of consumers for convenient food in fast-paced consumer scenarios.

[0036] 3) Improve product brightness and whiteness, optimize appearance quality; In the traditional hot paste-making process, local pasting unevenness or slight browning easily occurs during the heating process of raw starch, resulting in a dark appearance and low whiteness of the product. The cold water mixing process used in this invention avoids the damage to the structure of starch and the browning reaction caused by heating. The uniform dispersibility of granular cold water-swellable starch makes the product surface smoother, with an increase in whiteness and brightness of nearly 40%. The product has a cleaner and glossier appearance, with stronger visual appeal, meeting the high requirements of the market for food appearance quality.

[0037] III. Industrialization and application level: wide adaptability and market promotion value: The granular cold water-swellable starch in this invention can be prepared based on potato, mung bean, cassava, corn and other raw starches. The corresponding process can be adapted to the production of vermicelli / vermicelli made from different starch raw materials (such as mung bean vermicelli, potato vermicelli, etc.). There is no need to adjust the hot paste-making parameters for different raw materials, which solves the problem of large differences in hot paste-making conditions and poor adaptability of traditional processes, improves the universality of the process and the flexibility of raw material selection, and helps enterprises to adjust production plans according to market fluctuations in raw material prices, reducing raw material costs.

[0038] The following will be described in detail through specific examples.

[0039] Example 1 (correspondingFigure 1 Middle c curve A starch-based vermicelli / noodle preparation method without heat gelatinization and stir-frying, comprising the following steps: Step 1, preparation of granular cold-water-swellable starch: Select corn starch, pass through an 80-120 mesh sieve, and prepare granular cold-water-swellable starch by high-temperature and high-pressure reaction; 1) Weigh a certain amount of corn starch into a container, and add a mixed solution of ethanol and water, with the mass fraction of ethanol solution being 50%-80%, and the mass ratio of starch to ethanol solution being 1:2-8, and stir to obtain a uniform starch dough; 2) Put the prepared starch dough into a high-temperature and high-pressure microreactor, set the reaction temperature to 85-160℃, the stirring speed to 200-600 r / min, the reaction pressure to 0.2-0.7 MPa, and the reaction time to 0.5-2 h; 3) After the temperature reaches the set value (110℃-160℃), keep it for 5-30 min, and then take out the starch solution after cooling to room temperature, vacuum filter and wash with ethanol for 2-4 times, dry in an oven at 90-120℃ for 10-60 min, grind with a flour mill after drying, pass through a sieve (60-120 mesh), seal in a self-sealing bag, and store in a desiccator for standby use.

[0040] Step 2, preparation of vermicelli / noodle starch dough: Put the granular cold-water-swellable starch prepared in step 1 and potato raw starch into a mixer according to a mass ratio of 0.03:0.97, dry mix for 3-10 min until evenly mixed, then slowly add a certain amount of water, continue to stir for 5-25 min, and no heating is required during the stirring process, with the ambient temperature controlled at 20-30℃, to form a uniform, lump-free, and plastic starch dough (water content 40%-65%).

[0041] Step 3, production of vermicelli / noodle without heat gelatinization and stir-frying: Put the starch dough prepared in step 2 into a single-screw temperature-controllable self-cooked rice powder machine (extrusion temperature controlled at 80-95℃, cooking degree 75%-95%, extrusion pressure 0.5-1.5 MPa, die hole diameter 1.2-2.2 mm) to prepare vermicelli / noodle; freeze the vermicelli / noodle (water content 35%-60%) (-18~-30℃, time 3-12 h), age (temperature 0-10℃, time 8-24 h), dry (oven drying at 40-60℃ for 4-8 h, water content ≤14%), cool to room temperature, package, and obtain the finished product vermicelli / noodle.

[0042] Example 2 (corresponding Figure 1 Middle d curve,Figure 2 Middle c curve The mass ratio of the granular cold water-swellable starch to the raw starch (or other kinds of raw starch) is 0.05:0.95, and the remaining steps are the same as those of Example 1.

[0043] Example 3 (corresponding to Figure 1 Middle e curve The mass ratio of the granular cold water-swellable starch to the raw starch (or other kinds of raw starch) is 0.1:0.9, and the remaining steps are the same as those of Example 1.

[0044] Comparative Example 1 (corresponding to Figure 1 Middle a curve The starch-based vermicelli / noodle preparation method by hot water gelatinization is as follows: Step 1, preparation of hot water gelatinized starch: the potato raw starch is completely gelatinized by a boiling water bath, and then a dough is prepared by adding potato raw starch according to a mass ratio of 0.03:0.97 of gelatinized potato starch: potato raw starch.

[0045] Steps 2 and 3 are the same as those of Example 1.

[0046] Comparative Example 2 (corresponding to Figure 1 Middle b curve The starch-based vermicelli / noodle preparation method by hot water gelatinization is as follows: Step 1, preparation of hot water gelatinized starch: the corn raw starch is completely gelatinized by a boiling water bath, and then a dough is prepared by adding corn raw starch according to a mass ratio of 0.03:0.97 of gelatinized corn starch: corn raw starch.

[0047] Steps 2 and 3 are the same as those of Example 1.

[0048] Test Example 1 The vermicelli / noodles prepared in Examples 1-3 and Comparative Examples 1-2 are subjected to strain-stress tests, and the results are shown in Figure 1 Figure 1 ​It can be seen that the elongation at break (i.e. stretchability) of the vermicelli prepared from 3% hot water gelatinized potato starch and potato starch is 231.3%, and the tensile strength is 0.252 MP; the elongation at break of the vermicelli prepared from 3% hot water gelatinized corn starch and potato starch is 252.6%, and the tensile strength is 0.139 MP; after adding the heat-free paste-cooked corn granular cold water-swellable starch, the tensile strength and elongation at break of the prepared vermicelli are significantly improved compared with the hot water gelatinized potato vermicelli. Especially when the amount of corn granular cold water-swellable starch added is 5%, the tensile strength and elongation at break of the vermicelli are increased to 0.574 MP and 437.5%, respectively, which are nearly 2.28 times and 1.89 times higher than those of the 3% hot water gelatinized potato vermicelli, respectively. The results show that the heat-free paste-cooked starch-based vermicelli / noodle can effectively improve the gel strength and stretchability of potato vermicelli.

[0049] Example 4 (corresponding to d curve in FIG. 4) Figure 2 The heat-free paste-cooked starch-based vermicelli / noodle preparation method comprises the following steps: Step 1, preparation of granular cold water-swellable starch: Potato starch is selected, sieved through a 80-120 mesh sieve, and granular cold water-swellable starch is prepared by high-temperature and high-pressure reaction; 1) A certain amount of potato starch is weighed into a container and a mixed solution of ethanol and water is added, the mass fraction of the ethanol solution is 50%-80%, and the mass ratio of starch to ethanol solution is 1:2-8, and the starch powder is stirred to obtain a uniform starch dough; 2) The prepared starch dough is placed in a high-temperature and high-pressure microreactor, the reaction temperature is set to 85-160°C, the stirring speed is 200-600 r / min, the reaction pressure is 0.2-0.7 MPa, and the reaction time is 0.5-2 h; 3) After the temperature reaches the set value (110°C-160°C), keep the temperature for 5-30 min, cool to room temperature, and then take out the starch solution, vacuum filter and wash with ethanol for 2-4 times, the oven drying temperature is 90-120°C, and the drying time is 10-60 min, after drying, the starch is ground with a flour mill, sieved (60-120 mesh), sealed in a self-sealing bag, and stored in a desiccator for use.

[0050] Step 2, preparation of vermicelli / noodle starch dough: The granular cold water-swellable starch prepared in step 1 and potato starch are added to a mixer according to different mass ratios (0.05:0.95), dry mixed for 3-10 min to mix evenly, then a certain amount of water is slowly added, and stirring is continued for 5-25 min. During the stirring process, no heating is required, and the environmental temperature is controlled at 20-30°C, forming a uniform, lump-free, and plastic starch dough (water content 40%-65%).​

[0051] Step 3, production of non-thermal gelatinized starch-based vermicelli / noodle: The starch dough prepared in step 2 is sent to a single-screw temperature-controllable self-cooked rice flour machine (extrusion temperature controlled at 80-95℃, cooking degree 75%-95%, extrusion pressure 0.5-1.5 MPa, die hole diameter 1.2-2.2 mm) to prepare vermicelli / noodle; the vermicelli / noodle (water content 35%-60%) is frozen (-18~-30℃, time 3-12 h), aged (temperature 0-10℃, time 8-24 h), dried (oven dried at 40-60℃ for 4-8 h, water content ≤14%), cooled to room temperature, packaged, and the finished product vermicelli / noodle is obtained.

[0052] Example 5 (corresponding to e curve in Figure 2 ) The non-thermal gelatinized starch-based vermicelli / noodle preparation method comprises the following steps: Step 1, preparation of granular cold-water-swellable starch: Select cassava starch, pass through an 80-120 mesh sieve, and prepare granular cold-water-swellable starch by high-temperature high-pressure reaction; 1) A certain amount of cassava starch is weighed into a container and a mixed solution of ethanol and water is added, the mass fraction of the ethanol solution is 50%-80%, and the mass ratio of starch to ethanol solution is 1:2-8, and the starch dough is stirred to be uniform; 2) The prepared starch dough is placed in a high-temperature high-pressure microreactor, the reaction temperature is set to 85-160℃, the stirring speed is 200-600 r / min, the reaction pressure is 0.2-0.7 MPa, and the reaction time is 0.5-2 h; 3) After the temperature reaches the set value (110℃-160℃), keep the temperature for 5-30 min, cool to room temperature, and then take out the starch solution, vacuum filter and wash with ethanol for 2~4 times, oven dry at 90-120 ℃ for 10~60 min, and then grind with a flour mill, sieve (60-120 mesh), seal in a ziplock bag, and store in a desiccator for use.

[0053] Step 2, preparation of vermicelli / noodle starch dough: The granular cold-water-swellable starch prepared in step 1 and potato raw starch are added to a mixer in different mass ratios (0.05:0.95), dry mixed for 3-10 min to mix evenly, then a certain amount of water is slowly added, and stirring is continued for 5-25 min, without heating during the stirring process, and the environmental temperature is controlled at 20-30℃, to form a uniform, lump-free, and plastic starch dough (water content 40%-65%).

[0054] Step 3, production of non-thermal gelatinization starch-based vermicelli / noodle: The starch dough prepared in step 2 is sent to a single-screw temperature-controllable self-cooked rice flour machine (extrusion temperature controlled at 80-95℃, cooking degree 75%-95%, extrusion pressure 0.5-1.5 MPa, die hole diameter 1.2-2.2 mm) to prepare vermicelli / noodle; the vermicelli / noodle (water content 35%-60%) is frozen (-18~-30℃, time 3-12 h), aged (temperature 0-10℃, time 8-24 h), dried (oven dried at 40-60℃ for 4-8 h, water content ≤14%), cooled to room temperature, packaged, and the finished product vermicelli / noodle is obtained.

[0055] Example 6 (corresponding Figure 2 f curve) The non-thermal gelatinization starch-based vermicelli / noodle preparation method comprises the following steps: Step 1, preparation of granular cold-water-swellable starch: Select mung bean starch, pass through an 80-120 mesh sieve, and prepare granular cold-water-swellable starch by high-temperature high-pressure reaction; 1) A certain amount of mung bean starch is weighed into a container and a mixed solution of ethanol and water is added, the mass fraction of the ethanol solution is 50%-80%, and the mass ratio of starch to ethanol solution is 1:2-8, and the starch dough is stirred to be uniform; 2) The prepared starch dough is placed in a high-temperature high-pressure microreactor, the reaction temperature is set to 85-160℃, the stirring speed is 200-600 r / min, the reaction pressure is 0.2-0.7 MPa, and the reaction time is 0.5-2 h; 3) After the temperature reaches the set value (110℃-160℃), keep it for 5-30 min, cool it to room temperature, take out the starch solution, vacuum filter and wash it with ethanol for 2~4 times, oven dry at 90-120 ℃ for 10~60 min, grind with a flour mill after drying, pass through a sieve (60-120 mesh), seal in a ziplock bag and store in a desiccator, and use as needed.

[0056] Step 2, preparation of vermicelli / noodle starch dough: The granular cold-water-swellable starch prepared in step 1 and the mung bean starch are mixed in a mixer according to different mass ratios (0.05:0.95), dry mixed for 3-10 min to mix evenly, then a certain amount of water is slowly added and stirred for 5-25 min, the stirring process does not need to be heated, and the environmental temperature is controlled at 20-30℃, forming a uniform, lump-free, and plastic starch dough (water content 40%-65%).

[0057] Step 3, production of non-thermal gelatinized starch-based vermicelli / noodle: The starch dough prepared in step 2 was sent to a single-screw temperature-controllable self-cooked rice flour machine (extrusion temperature controlled at 80-95℃, cooking degree 75%-95%, extrusion pressure 0.5-1.5 MPa, die hole diameter 1.2-2.2 mm) to prepare vermicelli / noodle by extrusion; the vermicelli / noodle (water content 35%-60%) was frozen (-18~-30℃, time 3-12 h), aged (temperature 0-10℃, time 8-24 h), dried (dried in an oven at 40-60℃ for 4-8 h, water content ≤14%), cooled to room temperature, packaged, and the finished vermicelli / noodle was obtained.

[0058] Comparative Example 3 (corresponding to Figure 2 curve a in FIG. 1) A method for preparing starch-based vermicelli / noodle by hot water gelatinization, comprising the following steps: Step 1, preparation of hot water gelatinized starch: the potato raw starch was completely gelatinized by a boiling water bath, and then a dough was prepared by adding potato raw starch according to a mass ratio of 0.05:0.95 of gelatinized potato starch: potato raw starch.

[0059] Steps 2 and 3 are the same as those in Example 4.

[0060] Comparative Example 4 (corresponding to Figure 2 curve b in FIG. 1) A method for preparing starch-based vermicelli / noodle by hot water gelatinization, comprising the following steps: Step 1, preparation of hot water gelatinized starch: the corn raw starch was completely gelatinized by a boiling water bath, and then a dough was prepared by adding potato raw starch according to a mass ratio of 0.05:0.95 of gelatinized corn starch: potato raw starch.

[0061] Steps 2 and 3 are the same as those in Example 1.

[0062] Test Example 2 The vermicelli / noodle prepared in Examples 2, 4-6 and Comparative Examples 3-4 was subjected to strain-stress testing, and the results are shown in Figure 2 FIG. 2. Figure 2It can be seen that the elongation at break and gel strength of the vermicelli / vermicelli formed by mixing 5% hot water gelatinized potato starch and 5% hot water gelatinized corn starch with potato starch are low, wherein the elongation at break and gel strength of the vermicelli / vermicelli formed by mixing potato and 5% hot water gelatinized potato starch are 237.3% and 0.285 MP respectively, and the elongation at break and gel strength of the vermicelli / vermicelli formed by mixing potato and 5% hot water gelatinized corn starch are 280.1% and 0.278 MP respectively; the corn, potato, cassava and mung bean granular cold water swellable starches are prepared by the non-heat gelatinization thickening process, and the elongation at break and gel strength of the vermicelli / vermicelli prepared by mixing 5% corn granular cold water swellable starch, 5% potato granular cold water swellable starch, 5% cassava granular cold water swellable starch, 5% mung bean granular cold water swellable starch and potato starch are significantly improved; wherein the elongation at break and tensile strength of the vermicelli / vermicelli prepared by mixing potato and 5% corn granular cold water swellable starch are increased to 437.5% and 0.574 MP, which are increased by nearly 2.01-2.06 times and 1.56-1.84 times respectively compared with 5% hot water gelatinized potato vermicelli and 5% hot water gelatinized potato vermicelli / vermicelli.

[0063] Test Example 3 The optical analysis of different natural starches and granular cold water swellable starches (Examples 2, 4-6) was carried out, and the optical micrographs are shown in Figure 3 , the yellow background under bright field light and the black background under crossed polarized light, M: corn starch, Po: potato starch, T: cassava starch, Mb: mung bean starch; Native: native starch, VGS: granular cold water swellable starch. It can be seen from Figure 3 that the native starch has a uniform granular morphology, and all has a good polarized cross, indicating that the native starch is not gelatinized, and the starch characteristics are retained; and the granular cold water swellable starch formed by high temperature and high pressure treatment can maintain the granular morphology of the starch, but there is no obvious polarized cross, indicating that the starch is completely in a swellable state.

[0064] The granular morphology of different natural starches and granular cold water swellable starches (Examples 2, 4-6) was analyzed, and the results are shown in Figure 4 , M: corn starch, Po: potato starch, T: cassava starch, Mb: mung bean starch; VGS: granular cold water swellable starch. It can be seen from Figure 4It can be seen that all the original starch (corn starch, potato starch, cassava starch and mung bean starch) particles have regular morphology, smooth and compact surface; and the granular cold water-swellable starch formed by high temperature and high pressure treatment maintains the granular morphology of the original starch, the particle size is slightly swollen, but the starch surface starts to crack and slightly concave, which provides excellent conditions for rapid water absorption and rehydration of the granular cold water-swellable starch, and can effectively provide its viscosity and gel network structure.

[0065] Test Example 4 The color difference value of the vermicelli prepared in Examples 1-6 and Comparative Examples 1-2 was identified, wherein L is the lightness / brightness, a is red-green, b is yellow-blue, and W is the whiteness index. The results are shown in Table 1. As can be seen from Table 1, the brightness and whiteness of the vermicelli prepared from 3% hot water gelatinized potato starch and potato starch and 3% hot water gelatinized corn starch and potato starch are relatively low, and the brightness and whiteness are significantly improved by adding granular cold water-swellable starch (corn, potato, cassava and mung bean).

[0066] Table 1 Color difference value of vermicelli

[0067] Example 7 The preparation of granular cold water-swellable starch adopts an extrusion gelatinization molding process, and the steps are as follows: Corn starch was selected and sieved through an 80-120 mesh sieve.

[0068] 1) A certain amount of corn starch was weighed into a container and an ethanol solution (30%-90%) was added, the mass ratio of starch to ethanol was 1:0.1-1.5, and the mixture was stirred uniformly to obtain a starch dough (40%-90%); 2) The starch dough was sent into an extruder for high temperature extrusion gelatinization molding (the gelatinization temperature was 60-130°C, the molding zone temperature was fixed at 45-70°C, and the rotation speed was 50-200 r / min), and a long strip-shaped starch extrudate was obtained; 3) The strip-shaped extrudate was placed in a forced air oven for drying treatment, the drying temperature was 90-120°C, the drying time was 10-60 min, and after drying, the product was crushed at low temperature, sieved (60-120 mesh), sealed in a self-sealing bag and stored in a desiccator for standby use.

[0069] Corn starch: potato starch mass ratio was 0.03:0.97, and the remaining steps were the same as in Example 1.

[0070] Example 8 Corn starch was selected and sieved through an 80-120 mesh sieve.

[0071] 1) A certain amount of corn starch is weighed into a container, and an ethanol solution (30%-90%) is added, with the mass ratio of starch to ethanol being 1:0.1-1.5, and stirred uniformly to obtain a starch dough (40%-90%); 2) The starch dough is sent into an extruder for high-temperature extrusion gelatinization molding (the gelatinization temperature is 60-130°C, the molding zone temperature is fixed at 45-70°C, and the rotation speed is 50-200 r / min), to obtain a long strip-shaped starch extrudate; 3) The strip-shaped extrudate is placed in a blast oven for drying treatment, with the drying temperature being 90-120°C, and the drying time being 10-60 min, and after drying, low-temperature crushing is performed, sieving (60-120 mesh), and then placed in a self-sealing bag, sealed and stored in a desiccator, for standby use.

[0072] Corn starch: potato raw starch mass ratio is 0.05:0.95, and the remaining steps are the same as in Example 2.

[0073] Example 9 Corn starch is selected and sieved through an 80-120 mesh sieve.

[0074] 1) A certain amount of corn starch is weighed into a container, and an ethanol solution (30%-90%) is added, with the mass ratio of starch to ethanol being 1:0.1-1.5, and stirred uniformly to obtain a starch dough (40%-90%); 2) The starch dough is sent into an extruder for high-temperature extrusion gelatinization molding (the gelatinization temperature is 60-130°C, the molding zone temperature is fixed at 45-70°C, and the rotation speed is 50-200 r / min), to obtain a long strip-shaped starch extrudate; 3) The strip-shaped extrudate is placed in a blast oven for drying treatment, with the drying temperature being 90-120°C, and the drying time being 10-60 min, and after drying, low-temperature crushing is performed, sieving (60-120 mesh), and then placed in a self-sealing bag, sealed and stored in a desiccator, for standby use.

[0075] Corn starch: potato raw starch mass ratio is 0.1:0.9, and the remaining steps are the same as in Example 3.

[0076] Example 10 Potato starch is selected and sieved through an 80-120 mesh sieve.

[0077] 1) A certain amount of corn starch is weighed into a container, and an ethanol solution (30%-90%) is added, with the mass ratio of starch to ethanol being 1:0.1-1.5, and stirred uniformly to obtain a starch dough (40%-90%); 2) The starch dough is sent into an extruder for high-temperature extrusion gelatinization molding (the gelatinization temperature is 60-130°C, the molding zone temperature is fixed at 45-70°C, and the rotating speed is 50-200 r / min), to obtain long strip-shaped starch extrudates; 3) The strip-shaped extrudates are placed in a blast oven for drying treatment, the drying temperature is 90-120°C, the drying time is 10-60 min, after drying, low-temperature crushing is performed, sieving (60-120 mesh) is performed, the extrudates are placed in a self-sealing bag, sealed, and stored in a desiccator, for standby use.

[0078] Potato starch: the mass ratio of potato raw starch is 0.05:0.95, and the remaining steps are the same as in Example 4.

[0079] Example 11 Cassava starch is selected and sieved through a 80-120 mesh sieve.

[0080] 1) A certain amount of cassava starch is weighed into a container, and an ethanol solution (30%-90%) is added, the mass ratio of starch to ethanol is 1:0.1-1.5, and the starch dough (40%-90%) is obtained after stirring uniformly; 2) The starch dough is sent into an extruder for high-temperature extrusion gelatinization molding (the gelatinization temperature is 60-130°C, the molding zone temperature is fixed at 45-70°C, and the rotating speed is 50-200 r / min), to obtain long strip-shaped starch extrudates; 3) The strip-shaped extrudates are placed in a blast oven for drying treatment, the drying temperature is 90-120°C, the drying time is 10-60 min, after drying, low-temperature crushing is performed, sieving (60-120 mesh) is performed, the extrudates are placed in a self-sealing bag, sealed, and stored in a desiccator, for standby use.

[0081] Cassava starch: the mass ratio of potato raw starch is 0.05:0.95, and the remaining steps are the same as in Example 5.

[0082] Example 12 Green bean starch is selected and sieved through a 80-120 mesh sieve.

[0083] 1) A certain amount of green bean starch is weighed into a container, and an ethanol solution (30%-90%) is added, the mass ratio of starch to ethanol is 1:0.1-1.5, and the starch dough (40%-90%) is obtained after stirring uniformly; 2) The starch dough is sent into an extruder for high-temperature extrusion gelatinization molding (the gelatinization temperature is 60-130°C, the molding zone temperature is fixed at 45-70°C, and the rotating speed is 50-200 r / min), to obtain long strip-shaped starch extrudates; 3) The strip-shaped extrudate is placed in a blast oven drying process, the drying temperature is 90-120 ℃, the drying time is 10-60 min, after drying, it is crushed at low temperature, sieved (60-120 mesh), sealed in a self-sealing bag and stored in a dry dish for standby.

[0084] Green bean starch: the mass ratio of potato raw starch to potato starch is 0.05:0.95, and the remaining steps are the same as example 6.

[0085] Comparative example 5 The starch-based vermicelli / noodle preparation method of hot water gelatinization seasoning includes the following steps: Step 1, preparation of hot water gelatinized starch: the potato raw starch is completely gelatinized by a boiling water bath, and then a powder ball is prepared by adding potato raw starch according to the mass ratio of gelatinized potato starch to potato raw starch 0.1:0.9.

[0086] Steps 2 and 3 are the same as example 1.

[0087] Comparative example 6 The starch-based vermicelli / noodle preparation method of hot water gelatinization seasoning includes the following steps: Step 1, preparation of hot water gelatinized starch: the corn raw starch is completely gelatinized by a boiling water bath, and then a powder ball is prepared by adding corn raw starch according to the mass ratio of gelatinized corn starch to potato raw starch 0.1:0.9.

[0088] Steps 2 and 3 are the same as example 1.

[0089] The vermicelli / noodles prepared by examples 1-12 and comparative examples 1-6 are subjected to cooking test, the breaking rate and the best cooking time are shown in table 2, and the cooking characteristics are shown in table 3.

[0090] Table 2 Breaking rate and best cooking time of vermicelli / noodles

[0091] Table 3 Cooking characteristics of noodles

[0092] As shown in Table 2 and Table 3, the breakage rate of vermicelli prepared by potato and hot water gelatinized potato starch and potato and hot water gelatinized corn starch is more than 15%; the breakage rate is significantly reduced by the non-heat gelatinized and stir-fried granular cold water soluble starch and extruded granular cold water soluble starch, and the breakage rate is reduced to 4% when 5% potato granular cold water soluble starch is added, which is nearly 10 times higher than the breakage rate of potato and 3% hot water gelatinized potato starch. At the same time, the best cooking time is also significantly reduced, especially the cooking time of potato and 10% corn granular cold water soluble starch is 10 min 35 s, which effectively reduces the cooking time and maintains good toughness and toughness. As shown in Table 3, the water absorption rate of vermicelli prepared by potato and hot water gelatinized potato starch and potato and hot water gelatinized corn starch is between 130-141%, and the cooking loss is more than 20%; by using the non-heat gelatinized and stir-fried granular cold water soluble starch and extruded granular cold water soluble starch, the water absorption rate is significantly improved, the cooking loss is significantly reduced, and the quality of vermicelli is effectively improved.

[0093] Therefore, the present application adopts the above-mentioned non-heat gelatinized and stir-fried starch vermicelli noodle preparation method and product, which eliminates the need for separate hot gelatinization and stir-frying step in the traditional process, reduces energy consumption, and improves the gel strength and elongation at break of vermicelli / noodles, reduces cooking loss and breakage rate, and solves the problem of brittle breakage and hard taste of traditional vermicelli / noodles.

[0094] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit them, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for preparing starch vermicelli without heat-induced thickening, characterized in that, Includes the following steps: Step 1, Preparation of granular cold water soluble starch: Select one or more of the following starches: potato starch, mung bean starch, cassava starch, and corn starch. Pass the starch through an 80-120 mesh sieve and prepare granular cold water soluble starch using a high-temperature and high-pressure reaction or extrusion modification process. Step 2, Prepare the starch dough for vermicelli / noodles: Granular cold water-soluble starch and untreated starch are added to a mixer in a specific mass ratio. First, dry mix for 3-10 minutes until uniform. Then, slowly add water and continue stirring for 5-25 minutes. No heating is required during the stirring process. The ambient temperature is controlled at 20-30℃ to form a uniform, lumpy, and plastic starch dough. Step 3, Production of heat-free gelatinized thickening vermicelli / noodles: Starch dough is fed into a single-screw, temperature-controlled self-cooking rice noodle machine for extrusion to prepare vermicelli / noodles; the vermicelli / noodles are then frozen, aged, dried, cooled to room temperature, and packaged to obtain the finished vermicelli / noodles.

2. The method for preparing starch vermicelli without heat-induced thickening according to claim 1, characterized in that, In step 1, the specific steps for preparing granular, cold-water-swellable starch via high-temperature, high-pressure reaction are as follows: 1) Weigh out the original starch and place it in a container, add a mixed solution of ethanol and water, and stir to obtain a uniform starch dough; 2) The starch dough is placed in a high-temperature, high-pressure microreactor for reaction; 3) When the temperature reaches 110-160℃, keep it at that temperature for 5-30 minutes. After cooling to room temperature, take out the starch solution, vacuum filter it, wash it with ethanol, dry it in an oven, grind it with a grinder, pass it through a 60-120 sieve, put it in a self-sealing bag, seal it, and store it in a desiccator for later use.

3. The method for preparing starch vermicelli without heat-induced thickening according to claim 2, characterized in that: In step 1), the mass fraction of the ethanol solution is 50%-80%, and the mass ratio of starch to ethanol solution is 1:2-1:8; in step 3), the oven drying temperature is 90-120℃, and the drying time is 10-60 min.

4. The method for preparing starch vermicelli without heat-induced thickening according to claim 2, characterized in that, In step 2), the conditions for the high-temperature and high-pressure microreactor are: reaction temperature 85-160 ℃, stirring speed 200-600 r / min, reaction pressure 0.2-0.7 MPa, and reaction time 0.5-2 h.

5. The method for preparing starch vermicelli without heat-induced thickening according to claim 1, characterized in that, In step 1, the specific steps for preparing granular, cold-water-swellable starch using the extrusion modification process are as follows: 1) Weigh out the starch and place it in a container, add ethanol solution, and stir until well mixed to obtain starch dough; 2) The starch dough is fed into an extruder for high-temperature extrusion and gelatinization to obtain long strips of starch extrudate; 3) Place the strip extruded material in a forced-air drying oven at a temperature of 90-120℃ for 10-60 minutes. After drying, pulverize it at a low temperature, pass it through a 60-120 mesh sieve, seal it in a self-sealing bag, and store it in a desiccator for later use.

6. The method for preparing starch vermicelli without heat-induced thickening according to claim 5, characterized in that: In step 1), the concentration of the ethanol solution is 30%-90%, the mass ratio of starch to ethanol is 1:0.1-1.5, and the concentration of starch gluten is 40%-90%.

7. The method for preparing starch vermicelli without heat-induced thickening according to claim 5, characterized in that: In step 2), the gelatinization temperature during high-temperature extrusion gelatinization molding is 60-130℃, the molding zone temperature is fixed at 45-70℃, and the rotation speed is 50-200r / min.

8. The method for preparing starch vermicelli without heat-induced thickening according to claim 1, characterized in that: In step 2, the mass ratio of granular cold water-soluble starch to untreated starch is 0.03-0.2:1; the moisture content of the starch clumps is 40%-65%.

9. The method for preparing starch vermicelli without heat-induced thickening according to claim 1, characterized in that: In step 3, the extrusion temperature of the self-cooking rice noodle machine is 80-95℃, the degree of cooking is 75%-95%, the extrusion pressure is 0.5-1.5 MPa, and the die head diameter is 1.2-2.2 mm; the freezing temperature is -18--30℃, and the time is 3-12 h; the aging temperature is 0-10℃, and the time is 8-24 h; the oven drying temperature is 40-60℃, and the time is 4-8 h, and the moisture content of the rice noodles / vermicelli is ≤14%.

10. A type of starch-based vermicelli that requires no heat-based thickening, characterized in that: It is prepared by the preparation method according to any one of claims 1-9.

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