CN110615851A - Preparation of rice starch and method for researching physical and chemical properties - Google Patents
Preparation of rice starch and method for researching physical and chemical properties Download PDFInfo
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Abstract
The invention provides a method for preparing rice starch and researching physical and chemical properties in the technical field of starch preparation, which comprises the following steps of (1) preparing rice flour, namely, cleaning 30g of rice, soaking the rice in 150mL of distilled water for 18h, pulping, centrifuging, drying, and sieving by a 200-mesh sieve; (2) determination of amylose content in rice flour: determining by using an amylose analysis kit according to a Con A method; (3) preparing rice starch by an alkaline method; (4) preparing rice starch by an enzyme method; (5) preparation of rice starch by surfactant method (6) determination of breakage rate of rice starch granules: calculating the breakage rate of the starch by titrating the amount of reducing sugar generated by hydrolysis of the fungal alpha-amylase according to the sensitivity of the fungal alpha-amylase to the broken starch; (7) a rapid viscosity tester is used for testing the gelatinization characteristic of the rice starch; (8) analyzing the physical and chemical characteristics of the rice starch under different preparation methods; the rice starch prepared by the invention has good gelatinization characteristic.
Description
Technical Field
The invention belongs to the technical field of starch preparation, and particularly relates to a preparation method of rice starch and a method for researching physical and chemical properties of the rice starch.
Background
The starch separation method is different according to different raw materials, the key step in the processing of the corn and wheat starch is the separation of gluten protein, and the processing of the cassava starch mainly adopts a screening method. The separation of rice starch is difficult compared to corn and wheat starch mainly because the starch in the rice endosperm is tightly bound to protein components and the tiny particles make the rice starch difficult to precipitate in water, increasing the difficulty of separation and purification. However, in order to fully utilize the excellent characteristics of small particle size and white color of rice starch granules, the starch must be efficiently separated from other components, among which separation from protein is the first to be achieved.
At present, the industrial production of rice starch mainly adopts the process of alkaline hydrolysis protein combined with centrifugal separation, but a large amount of salt and alkaline waste liquid can be introduced in the alkaline treatment process, so that the cost of wastewater treatment and discharge is increased.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to overcome the defects in the prior art and provide a method for preparing rice starch and researching physicochemical characteristics.
The purpose of the invention is realized as follows: a method for preparing rice starch and researching physicochemical properties comprises (1) preparing rice flour by cleaning 30g rice, soaking in 150mL distilled water for 18h, pulping, centrifuging, drying, and sieving with 200 mesh sieve;
(2) determination of amylose content in rice flour: determining by using an amylose analysis kit according to a Con A method;
(3) the alkaline preparation method of the rice starch comprises the following steps: washing 30g of rice, soaking the rice in 150mL of distilled water for 18h, pulping, centrifuging, removing supernatant, uniformly mixing precipitate and 0.2% NaOH solution in a ratio of 1:5, placing the mixture on a shaking table for reaction for 48h, changing the NaOH solution once at intervals of 24h, sieving the mixture through a 100-mesh sieve to remove coarse particles after the reaction is finished, centrifuging at room temperature to remove supernatant, washing the precipitate for a plurality of times until the pH value of supernatant is neutral, freeze-drying a starch wet block, sieving the starch wet block through a 200-mesh sieve, and storing the obtained starch powder in a dryer for later use;
(4) preparing rice starch by an enzyme method: washing 30g of rice, soaking the rice in 150mL of distilled water for 18h, pulping, centrifuging, removing supernatant, uniformly mixing precipitate with 0.139% phosphoric acid buffer solution of Pronase protease (0.03 mol/L, pH 7.4) in a ratio of 1:5, placing the mixture on a shaking table for reaction for 48h, changing NaOH solution once at intervals of 24h, sieving the mixture through a 100-mesh sieve after the reaction is finished, centrifuging at room temperature (10000g, 10min), removing supernatant, washing the precipitate with water for 5 or 6 times until the pH value of supernatant is neutral, sieving the starch wet block through a 200-mesh sieve after freeze drying, and storing the obtained starch powder in a dryer for later use;
(5) preparing rice starch by a surfactant method: washing 30g of rice, soaking the rice in 150mL of distilled water for 18h, pulping, centrifuging, removing supernatant, uniformly mixing precipitate with 1.2% of a surfactant (SDS) solution in a ratio of 1:5, placing the mixture on a shaking table for reaction for 48h, changing NaOH solution once at an interval of 24h, sieving the mixture through a 100-mesh sieve after the reaction is finished to remove coarse particles, centrifuging at room temperature (10000g, 10min) to remove supernatant, washing the precipitate for 5 or 6 times until the pH value of supernatant is neutral, freeze-drying a starch wet block, and sieving the starch wet block through a 200-mesh sieve, wherein the obtained starch powder is stored in a dryer for later use;
(6) and (3) determination of breakage rate of rice starch granules: calculating the breakage rate of the starch by titrating the amount of reducing sugar generated by hydrolysis of the fungal alpha-amylase according to the sensitivity of the fungal alpha-amylase to the broken starch;
(7) the quick viscosity tester is used for testing the gelatinization characteristic of the rice starch: accurately weighing 2.4g of starch, adding 25mL of distilled water, mixing in a special cylindrical aluminum box of a width viscosity tester, and adjusting into starch milk with the concentration of 8.8%;
(8) and (3) analyzing the rice starch prepared in the steps (3) to (5), and specifically analyzing the viscoelasticity of the rice starch paste after gelatinization, the shear thinning degree of the rice starch paste, the thermal property of the rice starch, the grain shape of the rice starch and the grain size of the rice starch.
In order to realize the determination of the amylose content in the rice flour, the step (2) specifically comprises the following steps:
(201) accurately weighing 20mg of rice flour in a test tube with a plug, adding 1mL of DMSO, uniformly mixing in a vortex mixer, adding 2mL of 95% ethanol, uniformly oscillating, adding 4mL of ethanol, uniformly mixing, standing for 15min, 2000g, and centrifuging for 5 min;
(202) adding 0.2mL of DMSO into the precipitate, heating in a boiling water bath for 15min, adding 2mL of Con A, mixing uniformly, and diluting to 5mL (solution A) with Con A;
(203) taking 1.0mL of the solution A, putting the solution A into a 2.0mL centrifuge tube, adding 0.50mL of Con A solution, uniformly mixing for multiple times, and standing for 1 h;
(204) taking 0.5mL of the solution A, adding 4mL of 100mmol/L sodium acetate buffer solution with pH4.5, 0.1mL of amyloglucosidase and alpha-amylase solution, preserving the temperature for 10min at 40 ℃, taking 1.0mL, adding 4mL of GOPOD, preserving the temperature for 20min at 40 ℃, and then measuring the absorbance at 510 nm.
In order to realize the determination of the breakage rate of the rice starch granules, the step (4) specifically comprises the following steps:
(401) accurately weighing about 1g of starch in a conical flask, adding 0.05g of fungal alpha-amylase, adding 45mL of acetic acid buffer solution, keeping the temperature in a water bath at 30 ℃ for 15min, continuously stirring, adding 3mL of sulfuric acid solution and 2mL of sodium tungstate solution after the reaction is finished, uniformly mixing, keeping the mixture for 2min, filtering, and discarding the first 8-10 drops;
(402) immediately putting 5mL of filtrate in a test tube in the western region, adding 10mL of alkaline ferricyanate, mixing, immersing a measuring tube in a boiling water bath, timing for 20min, cooling the measuring tube by flowing tap water, completely transferring the reaction liquid into a conical flask, adding 1mL of starch potassium iodide solution, and fully and uniformly mixing;
(403) titrating with 0.1N thiosulfate until blue color disappears completely, and calculating the amount of reducing sugar;
(404) repeating the steps to make reagent blanks, wherein the calculation formula is as follows,
（1）；
wherein 1.64 is the coefficient of conversion of maltose to starch;
5 is the dilution factor of the sample;
(mg maltose/10 g starch) is obtained by looking up the table.
As a further improvement of the present invention, the temperature is maintained at 50 ℃ for 1min, the temperature is raised to 95 ℃ (3.75 min) at a speed of 12 ℃/min, the temperature is maintained below 95 ℃ for 2.5min, the temperature is lowered to 50 ℃ (3.75) min at 12 ℃/min, and the temperature is maintained at 50 ℃ for 1 min.
As a further improvement of the invention, in the step (5), the speed of the stirrer is kept at 160r/min during the gelatinization.
Compared with the prior art, the invention has the technical effects that:
a method for rapidly evaluating the slow release performance of the fertilizer by a leaching method is provided, and the advantages and disadvantages of the slow release performance of the fertilizer can be evaluated by comparing slow release performance curves of different fertilizers; paraffin, release factors, surfactants and the like are selected as raw materials to prepare the envelope material which has the anti-caking performance and the slow-release performance.
Drawings
FIG. 1 is a graph showing the protein content and the total starch content in the natural rice and the prepared rice starch according to the present invention.
FIG. 2 is a graph of gelatinization characteristics of rice starch prepared by different methods of the present invention.
FIG. 3 is a graph showing the gelatinization of native indica rice starch (Xiong nong No. 5) and enzymatically produced indica rice starch in the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
A method for preparing rice starch and researching physicochemical properties comprises the following steps,
(1) the rice flour is prepared by cleaning 30g rice, soaking in 150mL distilled water for 18h, pulping, centrifuging, drying, and sieving with 200 mesh sieve;
(2) determination of amylose content in rice flour: determining by using an amylose analysis kit according to a Con A method;
(3) the alkaline preparation method of the rice starch comprises the following steps: washing 30g of rice, soaking the rice in 150mL of distilled water for 18h, pulping, centrifuging, removing supernatant, uniformly mixing precipitate and 0.2% NaOH solution in a ratio of 1:5, placing the mixture on a shaking table for reaction for 48h, changing the NaOH solution once at intervals of 24h, sieving the mixture through a 100-mesh sieve to remove coarse particles after the reaction is finished, centrifuging at room temperature to remove supernatant, washing the precipitate for a plurality of times until the pH value of supernatant is neutral, freeze-drying a starch wet block, sieving the starch wet block through a 200-mesh sieve, and storing the obtained starch powder in a dryer for later use;
(4) preparing rice starch by an enzyme method: washing 30g of rice, soaking the rice in 150mL of distilled water for 18h, pulping, centrifuging, removing supernatant, uniformly mixing precipitate with 0.139% phosphoric acid buffer solution of Pronase protease (0.03 mol/L, pH 7.4) in a ratio of 1:5, placing the mixture on a shaking table for reaction for 48h, changing NaOH solution once at intervals of 24h, sieving the mixture through a 100-mesh sieve after the reaction is finished, centrifuging at room temperature (10000g, 10min), removing supernatant, washing the precipitate with water for 5 or 6 times until the pH value of supernatant is neutral, sieving the starch wet block through a 200-mesh sieve after freeze drying, and storing the obtained starch powder in a dryer for later use;
(5) preparing rice starch by a surfactant method: washing 30g of rice, soaking the rice in 150mL of distilled water for 18h, pulping, centrifuging, removing supernatant, uniformly mixing precipitate with 1.2% of a surfactant (SDS) solution in a ratio of 1:5, placing the mixture on a shaking table for reaction for 48h, changing NaOH solution once at an interval of 24h, sieving the mixture through a 100-mesh sieve after the reaction is finished to remove coarse particles, centrifuging at room temperature (10000g, 10min) to remove supernatant, washing the precipitate for 5 or 6 times until the pH value of supernatant is neutral, freeze-drying a starch wet block, and sieving the starch wet block through a 200-mesh sieve, wherein the obtained starch powder is stored in a dryer for later use;
(6) and (3) determination of breakage rate of rice starch granules: calculating the breakage rate of the starch by titrating the amount of reducing sugar generated by hydrolysis of the fungal alpha-amylase according to the sensitivity of the fungal alpha-amylase to the broken starch;
(7) the quick viscosity tester is used for testing the gelatinization characteristic of the rice starch: accurately weighing 2.4g of starch, adding 25mL of distilled water, mixing in a special cylindrical aluminum box of a width viscosity tester, and adjusting into starch milk with the concentration of 8.8%;
(8) and (3) analyzing the rice starch prepared in the steps (3) to (5), and specifically analyzing the viscoelasticity of the rice starch paste after gelatinization, the shear thinning degree of the rice starch paste, the thermal property of the rice starch, the grain shape of the rice starch and the grain size of the rice starch.
In order to realize the determination of the amylose content in the rice flour, the step (2) specifically comprises the following steps:
(201) accurately weighing 20mg of rice flour in a test tube with a plug, adding 1mL of DMSO, uniformly mixing in a vortex mixer, adding 2mL of 95% ethanol, uniformly oscillating, adding 4mL of ethanol, uniformly mixing, standing for 15min, 2000g, and centrifuging for 5 min;
(202) adding 0.2mL of DMSO into the precipitate, heating in a boiling water bath for 15min, adding 2mL of Con A, mixing uniformly, and diluting to 5mL (solution A) with Con A;
(203) taking 1.0mL of the solution A, putting the solution A into a 2.0mL centrifuge tube, adding 0.50mL of Con A solution, uniformly mixing for multiple times, and standing for 1 h;
(204) taking 0.5mL of the solution A, adding 4mL of 100mmol/L sodium acetate buffer solution with pH4.5, 0.1mL of amyloglucosidase and alpha-amylase solution, preserving the temperature for 10min at 40 ℃, taking 1.0mL, adding 4mL of GOPOD, preserving the temperature for 20min at 40 ℃, and then measuring the absorbance at 510 nm.
In order to realize the determination of the breakage rate of the rice starch granules, the step (4) specifically comprises the following steps:
(401) accurately weighing about 1g of starch in a conical flask, adding 0.05g of fungal alpha-amylase, adding 45mL of acetic acid buffer solution, keeping the temperature in a water bath at 30 ℃ for 15min, continuously stirring, adding 3mL of sulfuric acid solution and 2mL of sodium tungstate solution after the reaction is finished, uniformly mixing, keeping the mixture for 2min, filtering, and discarding the first 8-10 drops;
(402) immediately putting 5mL of filtrate in a test tube in the western region, adding 10mL of alkaline ferricyanate, mixing, immersing a measuring tube in a boiling water bath, timing for 20min, cooling the measuring tube by flowing tap water, completely transferring the reaction liquid into a conical flask, adding 1mL of starch potassium iodide solution, and fully and uniformly mixing;
(403) titrating with 0.1N thiosulfate until blue color disappears completely, and calculating the amount of reducing sugar;
(404) repeating the steps to make reagent blanks, wherein the calculation formula is as follows,
（1）；
wherein 1.64 is the coefficient of conversion of maltose to starch;
5 is the dilution factor of the sample;
(mg maltose/10 g starch) is obtained by looking up the table.
Keeping at 50 deg.C for 1min, increasing to 95 deg.C (3.75 min) at a speed of 12 deg.C/min, keeping at 95 deg.C below 2.5min, decreasing to 50 deg.C (3.75) min at 12 deg.C/min, and keeping at 50 deg.C for 1 min; during the gelatinization, the speed of the stirrer was kept at 160 r/min.
The amylose content in natural rice measured by the ConA method was: 20.8% of long-shaped rice (Xiong No. 5), 13.2% of polished round-grained rice (M202) and 1.7% of glutinous rice (Youguo No. 3), wherein the purity of starch is mainly prompted by two important indexes of protein content and total starch content, so that the protein content and the total starch content of the starch obtained by separating the rice flour and different preparation methods (step (3) -step (5)) are respectively determined, and the attached drawing 1 shows.
To further investigate the effect of different preparation methods on the quality characteristics of rice starch, the gelatinization characteristics of the starch isolated by the three methods were compared next.
In the starch, amylose and amylopectin are associated through hydrogen bonds to form a microcrystalline cluster region, so that starch factors are insoluble in cold water, but as the temperature rises, starch granules begin to expand, a water phase begins to enter the starch granules, the amylose is gradually dissolved out, the viscosity of the solution continuously rises, the gelatinization starting temperature is the temperature when the viscosity of the solution begins to rise, the temperature when the viscosity rises to the maximum is the gelatinization peak temperature of the starch, and the viscosity at the moment is the peak temperature viscosity; when the starch is continuously heated at high temperature, the intermolecular force of the starch is weaker and weaker, the microcrystalline bundles of the starch granules are correspondingly disintegrated, the granules are broken, the viscosity is reduced, and the change of the process is usually measured by using a disintegration value; when the temperature is reduced, the starch molecules are rearranged to form a gel network structure, so that the viscosity begins to rise again, and the rising value is used for measuring the process.
The gelatinization characteristic of the starch is measured by a rapid viscometer, and as can be seen from figure 1, the damage degree of an alkaline method and a surfactant method to starch granules is large, the larger the damage rate of the starch is, the more easily the granules are broken in the heating gelatinization process, and the gelatinization peak temperature is also reduced; for the glutinous rice starch with little amylose content, the gelatinization characteristic of the glutinous rice starch is not influenced by the preparation method, and the gelatinization characteristic parameters of the glutinous rice starch prepared by different methods have no obvious change, so that the gelatinization characteristic of the starch can be influenced by different preparation methods, but the influence degrees of the different preparation methods are different due to the difference of the varieties of the starch and the amylose content. Comparing the three rice starches with different amylose contents, it was also found that the higher the amylose content, the higher the degree of gelatinization, the higher the peak temperature and the higher the retrogradation value, without the lower the retrogradation value (fig. 2).
From fig. 2, it can be seen more intuitively that the gelatinization viscosity changes in the whole process, the gelatinization curves of the starches prepared by the three different methods are very different, and in the early stage of gelatinization, the viscosity of the starches prepared by the alkaline method and the surfactant method is increased at a higher rate than that of the starch prepared by the enzymatic method and reaches the peak viscosity at a lower temperature, so that the gelatinization peak temperature of the starches prepared by the alkaline method and the surfactant method is lower than that of the starch prepared by the enzymatic method, which is related to that the combination between the starch and the lipid is damaged by the excitation of the alkaline method and the surface core, so that the starch granules are easier to absorb water and swell, and the enzyme method can maintain the natural structure of the starch granules higher, and the damage degree of the starch by the alkaline method and the surfactant method is larger.
As can be seen from FIG. 3, the peaks of the two curves are very similar, which indicates that the starch produced by the enzymatic method has better gelatinization property of the original native starch, and the year of the starch produced by the enzymatic method is higher than that of the native starch in the whole gelatinization process, because the substances such as protein, crude fiber and the like are removed in the process of separating the starch, the purity of the starch is further improved, and the gelatinization viscosity is also improved.
In conclusion, compared with the alkaline method and the surfactant method, the starch prepared by the enzyme method can better keep the gelatinization characteristic of the original natural starch.
The present invention is not limited to the above embodiments, and based on the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some technical features without creative efforts based on the disclosed technical solutions, and these substitutions and modifications are all within the protection scope of the present invention.
Claims (5)
1. A method for preparing rice starch and researching physicochemical properties is characterized by comprising the following steps,
(1) the rice flour is prepared by cleaning 30g rice, soaking in 150mL distilled water for 18h, pulping, centrifuging, drying, and sieving with 200 mesh sieve;
(2) determination of amylose content in rice flour: determining by using an amylose analysis kit according to a Con A method;
(3) the alkaline preparation method of the rice starch comprises the following steps: washing 30g of rice, soaking in 150mL of distilled water for 18h, pulping, centrifuging, removing supernatant, uniformly mixing precipitate with 0.2% NaOH solution in a ratio of 1:5, placing on a shaking table for reaction for 48h, changing the NaOH solution once at an interval of 24h, sieving by a 100-mesh sieve to remove coarse particles after the reaction is finished, centrifuging at room temperature to remove supernatant, washing the precipitate for a plurality of times until the pH value of the supernatant is neutral, freeze-drying a starch wet block, sieving by a 200-mesh sieve, and storing the obtained starch powder in a dryer for later use
(4) Preparing rice starch by an enzyme method: washing 30g of rice, soaking the rice in 150mL of distilled water for 18h, pulping, centrifuging, removing supernatant, uniformly mixing precipitate with 0.139% phosphoric acid buffer solution of Pronase protease (0.03 mol/L, pH 7.4) in a ratio of 1:5, placing the mixture on a shaking table for reaction for 48h, changing NaOH solution once at intervals of 24h, sieving the mixture through a 100-mesh sieve after the reaction is finished, centrifuging at room temperature (10000g, 10min), removing supernatant, washing the precipitate with water for 5 or 6 times until the pH value of supernatant is neutral, sieving the starch wet block through a 200-mesh sieve after freeze drying, and storing the obtained starch powder in a dryer for later use;
(5) preparing rice starch by a surfactant method: washing 30g of rice, soaking the rice in 150mL of distilled water for 18h, pulping, centrifuging, removing supernatant, uniformly mixing precipitate with 1.2% of a surfactant (SDS) solution in a ratio of 1:5, placing the mixture on a shaking table for reaction for 48h, changing NaOH solution once at an interval of 24h, sieving the mixture through a 100-mesh sieve after the reaction is finished to remove coarse particles, centrifuging at room temperature (10000g, 10min) to remove supernatant, washing the precipitate for 5 or 6 times until the pH value of supernatant is neutral, freeze-drying a starch wet block, and sieving the starch wet block through a 200-mesh sieve, wherein the obtained starch powder is stored in a dryer for later use;
(6) and (3) determination of breakage rate of rice starch granules: calculating the breakage rate of the starch by titrating the amount of reducing sugar generated by hydrolysis of the fungal alpha-amylase according to the sensitivity of the fungal alpha-amylase to the broken starch;
(7) the quick viscosity tester is used for testing the gelatinization characteristic of the rice starch: accurately weighing 2.4g of starch, adding 25mL of distilled water, mixing in a special cylindrical aluminum box of a width viscosity tester, and adjusting into starch milk with the concentration of 8.8%;
(8) and (3) analyzing the rice starch prepared in the steps (3) to (5), and specifically analyzing the viscoelasticity of the rice starch paste after gelatinization, the shear thinning degree of the rice starch paste, the thermal property of the rice starch, the grain shape of the rice starch and the grain size of the rice starch.
2. The method for preparing rice starch and researching physical and chemical properties of rice starch according to claim 1, wherein the step (2) comprises the following steps:
(201) accurately weighing 20mg of rice flour in a test tube with a plug, adding 1mL of DMSO, uniformly mixing in a vortex mixer, adding 2mL of 95% ethanol, uniformly oscillating, adding 4mL of ethanol, uniformly mixing, standing for 15min, 2000g, and centrifuging for 5 min;
(202) adding 0.2mL of DMSO into the precipitate, heating in a boiling water bath for 15min, adding 2mL of Con A, mixing uniformly, and diluting to 5mL (solution A) with Con A;
(203) taking 1.0mL of the solution A, putting the solution A into a 2.0mL centrifuge tube, adding 0.50mL of Con A solution, uniformly mixing for multiple times, and standing for 1 h;
(204) taking 0.5mL of the solution A, adding 4mL of 100mmol/L sodium acetate buffer solution with pH4.5, 0.1mL of amyloglucosidase and alpha-amylase solution, preserving the temperature for 10min at 40 ℃, taking 1.0mL, adding 4mL of GOPOD, preserving the temperature for 20min at 40 ℃, and then measuring the absorbance at 510 nm.
3. The method for preparing rice starch and researching physical and chemical properties of rice starch according to claim 1, wherein the step (4) comprises the following steps:
(401) accurately weighing about 1g of starch in a conical flask, adding 0.05g of fungal alpha-amylase, adding 45mL of acetic acid buffer solution, keeping the temperature in a water bath at 30 ℃ for 15min, continuously stirring, adding 3mL of sulfuric acid solution and 2mL of sodium tungstate solution after the reaction is finished, uniformly mixing, keeping the mixture for 2min, filtering, and discarding the first 8-10 drops;
(402) immediately putting 5mL of filtrate in a test tube in the western region, adding 10mL of alkaline ferricyanate, mixing, immersing a measuring tube in a boiling water bath, timing for 20min, cooling the measuring tube by flowing tap water, completely transferring the reaction liquid into a conical flask, adding 1mL of starch potassium iodide solution, and fully and uniformly mixing;
(403) titrating with 0.1N thiosulfate until blue color disappears completely, and calculating the amount of reducing sugar;
(404) repeating the steps to make reagent blanks, wherein the calculation formula is as follows,
（1）；
wherein 1.64 is the coefficient of conversion of maltose to starch;
5 is the dilution factor of the sample;
(mg maltose/10 g starch) is obtained by looking up the table.
4. The method for preparing rice starch and researching physical and chemical properties of rice starch according to claim 1, wherein the determination conditions in the step (5) are specifically as follows: keeping at 50 deg.C for 1min, increasing to 95 deg.C (3.75 min) at a speed of 12 deg.C/min, keeping at 95 deg.C below 2.5min, decreasing to 50 deg.C (3.75) min at 12 deg.C/min, and keeping at 50 deg.C for 1 min.
5. The method for preparing rice starch and studying physicochemical properties of the rice starch according to claim 4, wherein in the step (5), the speed of the stirrer is maintained at 160r/min during the gelatinization.
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| CN111499930A (en) * | 2020-06-16 | 2020-08-07 | 佛山市国农淀粉有限公司 | Physically modified starch and preparation method thereof |
| CN115053967A (en) * | 2022-08-04 | 2022-09-16 | 北京逯博士行为医学科技研究院有限公司 | Preparation method of nutritional meal bag based on fat reduction |
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| CN111499930A (en) * | 2020-06-16 | 2020-08-07 | 佛山市国农淀粉有限公司 | Physically modified starch and preparation method thereof |
| CN115053967A (en) * | 2022-08-04 | 2022-09-16 | 北京逯博士行为医学科技研究院有限公司 | Preparation method of nutritional meal bag based on fat reduction |
| CN115053967B (en) * | 2022-08-04 | 2022-11-01 | 北京逯博士行为医学科技研究院有限公司 | Preparation method of nutritional meal bag based on fat reduction |
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