Extraction method of wheat bran polysaccharide, rice noodle prepared by extraction method and method
Technical Field
The invention particularly relates to an extraction method of wheat bran polysaccharide, a rice noodle prepared by the extraction method and a method.
Background
Wheat bran is a byproduct of wheat flour processing, is the remaining part of wheat after embryo bud and endosperm are extracted, and mainly consists of a wheat cortex and an aleurone layer. Besides a certain amount of starch, protein and fat, the bran mainly contains about 46 percent of non-starch polysaccharides, including pectin polysaccharides, cellulose polysaccharides and non-cellulose polysaccharides composed of arabinoxylans, mixed chain beta-glucans, glucomannans, galactans, xylans and the like. A large number of researches show that the wheat bran contains a large number of nutrient components necessary for human bodies, has the effects of moistening lung, moistening skin, preventing and resisting cancer, strengthening spleen and stomach, blacking hair and fixing hair, clearing intestines and stomach and the like, and has high medical care value. However, the wheat bran processed in China is basically and directly applied to the industries of feed industry, wine brewing, vinegar making, soy sauce and the like, deep processing and recycling are few, the economic value is not high, and wheat bran polysaccharide is easy to lose in the processing process. The wheat bran polysaccharide has the effects of resisting aging, improving immunity, resisting cancer, reducing blood fat, reducing blood pressure and the like, and has wide application prospect.
In recent years, common technologies for extracting wheat bran polysaccharide include water extraction, alkaline extraction, acid extraction and the like, but the methods have certain defects, such as low extraction rate of the wheat bran polysaccharide extracted by the water method, damage to the structure of the wheat bran polysaccharide by an acid-base reagent to a certain extent, influence on the biological activity of the wheat bran polysaccharide, and easily cause environmental pollution and safety problems. For example, CN 108753901A discloses a method for preparing wheat bran active polysaccharide by a fermentation method, but the safety is not high.
The rice noodle is a linear product made from high-quality rice through the processes of fermentation, grinding, clarifying and filtering, steaming, extruding, boiling and the like. The rice noodles are slender, white, flexible and various in eating methods. Generally, the rice can be divided into two categories, one category is prepared by grinding fermented rice into powder, which is commonly called as sour pulp rice noodles, the process is complex, and the production period is long. The method is characterized in that: the rice noodle has good bones and muscles, is smooth and sweet, has rice faint scent, and is a traditional preparation method. The other type is that the rice is directly extruded and formed after being ground into powder, and the rice is pasted and formed by the heat of friction, which is called dry slurry rice noodles. The dried thick liquid rice noodles are dried in the sun to form the dried rice noodles which are convenient to carry and store and are boiled and swollen when being eaten. The dried rice milk has hard bones and muscles, is chewed and long-thread, but lacks the faint scent of rice. The existing commercial rice noodles are inconvenient to store and have short shelf life, and over time, the rice noodles become sour, crisp and fragile, or are hard and hard to swallow. Because the rice noodle is sour and has high starch content, partial people are easy to eat the rice noodle to cause dyspepsia and acid regurgitation. Most of the rice noodles prepared by the existing method use additives, so that the rice noodles lack the faint scent of rice, are easy to be bonded into a ball and seriously mixed with soup when being brewed or steamed in boiling water, have soft mouthfeel and no biting strength, and are not suitable for marketization requirements. CN104905126A discloses a method for preparing nutritious health noodles rich in bran dietary fiber, which utilizes a process of ultrasonic-assisted enzymolysis and composite microbial fermentation to extract fiber dietary fiber from bran, and the nutritious health noodles are rich in bran dietary fiber, including water-soluble bran dietary fiber and water-insoluble bran dietary fiber, but the reagents used by the nutritious health noodles are easy to cause environmental pollution.
Disclosure of Invention
The technical problem to be solved by the invention is to overcome the defects in the prior art and provide the extraction method of the wheat bran polysaccharide, which has the advantages of high purity and extraction rate of the wheat bran polysaccharide, no damage to the structure of the wheat bran polysaccharide, no influence on the biological activity of the wheat bran polysaccharide, no reagent pollution, safety, environmental protection, simple method, low cost and suitability for industrial production.
The invention further aims to solve the technical problem of overcoming the defects in the prior art and provide the rice noodle which has good color and luster, good taste, rice flavor retention, long shelf life, easy digestion and blood sugar reducing effect.
The invention further aims to solve the technical problem of overcoming the defects in the prior art and provide a method for manufacturing rice noodles, which can improve the elasticity and the smoothness of rice noodles, has moderate hardness, high rehydration rate, low breakage rate, simple method and low cost and is suitable for industrial production.
The technical scheme adopted by the invention for solving the technical problems is as follows: a method for extracting wheat bran polysaccharide comprises the following steps:
(1) grinding wheat bran, sieving, heating for inactivation, adding water, heating in water bath, adding amylase preparation, stirring, heating in water bath, adjusting pH to neutral or alkaline, adding neutral protease preparation, and heating in water bath to obtain de-starch and protein bran solution;
(2) adjusting the pH value of the de-starched and protein bran liquid obtained in the step (1) to be acidic, adding a saccharifying enzyme preparation, heating in a water bath under stirring, centrifuging, washing precipitates with water for more than or equal to 2 times, and drying to obtain a wheat bran polysaccharide crude product;
(3) and (3) adding water into the wheat bran polysaccharide crude product obtained in the step (2), heating in a water bath, centrifuging, taking supernatant, adding an alcohol solution, carrying out ultrasonic extraction, centrifuging, precipitating and drying to obtain the wheat bran polysaccharide.
Preferably, in the step (1), the mass content of the wheat bran polysaccharides in the wheat bran is 10-26%.
Preferably, in the step (1), the mesh number of the sieve is 40-100 meshes.
Preferably, in the step (1), the temperature for heating and passivating is 110-130 ℃ and the time is 10-20 min. The purpose of said inactivation is to inactivate the activity of the endogenous enzyme, so that the activity of the endogenous enzyme is reduced or even eliminated, thereby not affecting the extraction of the polysaccharide. At the inactivation temperature and time, the activity of the endogenous enzyme can be significantly inhibited. If the temperature is too low and the time is too short, the inactivation effect on endogenous enzymes is poor; if the temperature is too high and the time is too long, the inactivation of the enzyme is also not facilitated, and the resource waste is caused.
Preferably, in the step (1), the volume-to-mass ratio (L/kg) of the amount of the added water to the wheat bran raw material is 10-50: 1. The proportion can ensure that water and the wheat bran raw material are fully mixed, the soaking effect is good, and the dissolution and extraction of wheat bran polysaccharide are facilitated.
Preferably, in the step (1), before the amylase preparation is added, the water bath heating temperature is 20-90 ℃ (more preferably 40-80 ℃), and the time is 1-10 h (more preferably 4-8 h). The purpose of the water bath prior to the addition of the amylase preparation is to provide a good temperature environment for the enzyme to function quickly.
Preferably, in the step (1), after the amylase preparation is added, the water bath heating temperature is 20-90 ℃ (more preferably 40-80 ℃), and the time is 10-120 min (more preferably 20-60 min). The purpose of the water bath after the addition of the amylase preparation is to allow the enzyme preparation to exert its maximum activity to remove the starch from the wheat bran. The enzymolysis effect of the amylase preparation is optimal under the temperature and the time.
Preferably, in the step (1), the dosage of the amylase preparation is 3-15% of the mass of the wheat bran raw material. The amylase preparation is added for removing starch from wheat bran.
Preferably, in the step (1), the amylase preparation is one or more of a high-temperature alpha-amylase preparation, a beta-amylase preparation or a high-peak amylase preparation.
Preferably, in the step (1), the pH value is adjusted to 7.0-10.0. The purpose of the pH adjustment is to allow the neutral protease preparation to react within its optimum pH range.
Preferably, in the step (1), one or more of 0.1-1.0 mol/L NaOH aqueous solution, phosphate buffer solution or potassium dihydrogen phosphate aqueous solution is used for adjusting the pH value. The concentration is easy to adjust the pH value not to increase too fast or too slow, nor too much.
Preferably, in the step (1), the dosage of the neutral protease preparation is 3-10% of the mass of the wheat bran raw material. The neutral protease preparation is added to reduce the protein content of bran.
Preferably, in the step (1), after the neutral protease preparation is added, the water bath heating temperature is 20-90 ℃, and the time is 30-120 min (more preferably 40-80 min). The purpose of the water bath after the neutral protease preparation is to maximize the activity of the neutral protease. At said temperature and time, the activity of the enzyme is better. If the temperature is too low and the time is too short, the effect of the enzyme is not good; if the temperature is too high and the time is too long, the activity of the enzyme is also not favorable, and the resource waste is caused.
Preferably, in the step (2), the pH value is adjusted to 3.0-5.0. The purpose of adjusting the pH is to ensure that the activity of the saccharifying enzyme preparation reacts in its optimum pH range.
Preferably, in the step (2), the pH value is adjusted by one or more of 0.1-1.0 mol/L hydrochloric acid aqueous solution, lactic acid aqueous solution or citric acid aqueous solution. The concentration is easy to adjust the pH value not to increase too fast or too slow, nor too much.
Preferably, in the step (2), the dosage of the saccharifying enzyme preparation is 1-5% of the mass of the wheat bran raw material. The purpose of adding the saccharifying enzyme preparation is to further remove residual starch in the wheat bran. The purpose of adding the saccharifying enzyme preparation is to further remove residual starch in the wheat bran. Saccharifying enzymes can slowly cleave the alpha-1.6 linkage in addition to the alpha-1.4 linkage from the non-reducing end of the starch chain. Therefore, it can rapidly cleave off the grape unit from the non-reducing end of amylose, thereby hydrolyzing amylopectin to glucose, and achieving further starch removal.
Preferably, in the step (2), the temperature of the water bath heating is 20-90 ℃, and the time is 30-120 min (more preferably 40-80 min). The purpose of the water bath after the addition of the saccharifying enzyme preparation is to allow sufficient reaction, the temperature must not be too high, otherwise the structure of the enzyme is destroyed and may lose its activity.
Preferably, in the step (2), the drying temperature is 20-90 ℃ and the drying time is 1-40 h.
Preferably, in the step (3), the volume-to-mass ratio (L/kg) of the amount of the added water to the wheat bran raw material is 1-100: 1 (more preferably 2-20: 1). The proportion can ensure good soaking effect and is beneficial to dissolving and extracting the water-soluble components of the wheat bran.
Preferably, in the step (3), the water bath heating temperature is 40-90 ℃ and the time is 10-60 min. The purpose of the water bath is to enable more water-soluble ingredients in the wheat bran to be dissolved out.
Preferably, in the step (3), the volume ratio of the alcohol solution to the supernatant is 1-6: 1. The alcoholic solution is added because some components of the wheat bran have reduced solubility in the alcoholic solution and precipitate out. The proportion can ensure that the wheat bran polysaccharide is fully separated out.
Preferably, in the step (3), the volume fraction of the alcoholic solution is 80-99%.
Preferably, in the step (3), the alcohol solution is an ethanol solution and/or a methanol solution.
Preferably, in the step (3), the power of the ultrasonic extraction is 100-2000W (more preferably 200-1000W), and the time is 10-120 min (more preferably 20-80 min). The purpose of the ultrasonic is to increase the penetrating power of the solvent by utilizing the cavitation effect generated by the ultrasonic, the action of the solvent raw material is more sufficient, the dissolution of the target extract can be increased, the extraction rate is accelerated, the extraction time is shortened, and meanwhile, the purity of the extract can also be increased.
Preferably, in the step (3), the drying temperature is 20-90 ℃ and the drying time is 1-40 h.
The technical scheme adopted for further solving the technical problems is as follows: a rice noodle is mainly prepared from semen oryzae Sativae powder, semen oryzae powder, corn starch, wheat bran polysaccharide extracted by the method, and water.
Preferably, the rice flour comprises the following raw materials in parts by weight: 50-150 parts of polished round-grained rice flour, 100-600 parts of long-grained rice flour, 10-250 parts of corn starch, 0.015-0.5 part of wheat bran polysaccharide extracted by the method and 5-50 parts of water. The amylose content of the polished round-grained rice is 17-25%, the amylose content of the long-grained rice is 26-31%, the consistency of the polished round-grained rice is higher than that of the long-grained rice, and the amylose and protein content are low, so that the polished round-grained rice is slightly glutinous and has strong viscosity; long-grain rice is the lowest viscosity of all rice; the round-grained rice, the long-grained rice and the corn starch are selected and mixed when the rice noodles are manufactured, so that the rice noodles have good toughness and are not easy to break when being cooked. The wheat bran polysaccharide is added, so that the prepared rice noodle has the advantages of good color and luster, good taste, rice aroma retention, long shelf life, easy digestion and blood sugar reducing effect.
Preferably, the granularity of the polished round-grained rice flour and the long-grained rice flour is 80-100 meshes.
The technical scheme adopted by the invention for further solving the technical problems is as follows: a rice noodle is prepared by mixing semen oryzae Sativae powder and semen oryzae powder, adding corn starch and wheat bran polysaccharide, adding water, mixing to obtain wet powder block, steaming with boiling water, pouring the steamed rice powder block into a rice noodle forming machine, squeezing to obtain powder, cutting the extruded vermicelli, cooling in cold water, steaming with boiling water, taking out, rinsing with cold water, rubbing, draining, and drying in the shade.
Preferably, the time for steaming the wet powder block with boiling water in a water-proof manner is 10-60 min (more preferably 20-40 min). The reason why the water-proof steaming is because the leakproofness is good, will not cause the too much volatilization of ground rice flavor composition, and because its even equilibrium of heating power, so can not cause destruction to the nutrition structure of rice noodle.
Preferably, the diameter of the outlet aperture of the rice noodle forming machine is 2-3 mm.
Preferably, the extruded vermicelli is cut off at a length of 0.5-2.0 m.
Preferably, the temperature of the cooled cold water is 15-25 ℃. The purpose of cooling is to bring it back to its original state.
Preferably, the cooled vermicelli is steamed in boiling water for 5-30 min. The secondary water-resisting steaming is used for steaming the vermicelli, and the secondary water-resisting steaming is used for preventing the vermicelli from being pasted and agglomerated after cooling and retrogradation.
Preferably, the temperature of the cold water for rinsing is 15-25 ℃.
The water used in the present invention is preferably distilled water.
The invention has the following beneficial effects:
(1) the purity of the wheat bran polysaccharide obtained by the extraction method is up to 78.5%, the extraction rate is up to 93.4%, the structure of the wheat bran polysaccharide is not damaged, the biological activity of the wheat bran polysaccharide is not influenced, no reagent pollution is caused, the method is safe and environment-friendly, simple, low in cost and suitable for industrial production;
(2) the rice flour disclosed by the invention is good in color and taste, retains rice fragrance, is long in shelf life and easy to digest, and has the effect of reducing blood sugar;
(3) the rice noodle manufacturing method adopts a secondary cooking extrusion molding method, can improve the elasticity and smoothness of the rice noodle, has moderate hardness, high rehydration rate, low breakage rate, simple method and low cost, and is suitable for industrial production.
Detailed Description
The present invention will be further described with reference to the following examples.
The wheat bran used in the embodiment of the invention is commercially available, wherein the mass content of wheat bran polysaccharide is 20%; the high-temperature alpha-amylase preparation, the beta-amylase preparation, the peak amylase preparation, the neutral protease preparation and the saccharifying enzyme preparation used in the embodiment of the invention are all purchased from sigma; the phosphate buffer used in the examples of the present invention was purchased from national pharmaceutical group chemical reagents, ltd; the raw materials or food additives used in the examples of the present invention are obtained by conventional commercial methods unless otherwise specified.
Method for extracting wheat bran polysaccharides in example 1
(1) Grinding 100g of wheat bran, sieving with a 40-mesh sieve, heating and inactivating at 110 ℃ for 10min, adding 1L of distilled water, heating in a water bath at 40 ℃ for 8h, adding 3.0g of high-temperature alpha-amylase preparation, continuously heating in a water bath at 40 ℃ for 60min under stirring, adjusting the pH value to 7.5 by using 0.1mol/L NaOH aqueous solution, adding 3.0g of neutral protease preparation, and heating in a water bath at 40 ℃ for 80min to obtain a de-starched and protein bran liquid;
(2) adjusting the pH value of the de-starched and protein bran liquid obtained in the step (1) to 3.5 by using 0.1mol/L hydrochloric acid aqueous solution, adding 1.0g of saccharifying enzyme preparation, heating in water bath for 80min at 40 ℃ under stirring, centrifuging, washing the precipitate for 3 times, placing in a drying oven, and drying for 30h at 40 ℃ to obtain a wheat bran polysaccharide crude product;
(3) adding 1000mL of water into the wheat bran polysaccharide crude product obtained in the step (2), heating in a water bath at 40 ℃ for 60min, centrifuging, taking 500mL of supernatant, adding 500mL of ethanol solution with volume fraction of 95%, ultrasonically extracting for 20min under the ultrasonic power of 1000W, centrifuging, precipitating at 40 ℃, and drying for 30h to obtain 23.5g of wheat bran polysaccharide # 1.
Through phloroglucinol method detection, the purity of the wheat bran polysaccharide obtained in the embodiment of the invention is 75.7%, and the extraction rate is 88.9%.
Method for extracting wheat bran polysaccharides in example 2
(1) Grinding 100g of wheat bran, sieving with a 100-mesh sieve, heating and inactivating at 130 ℃ for 20min, adding 3L of distilled water, heating in water bath at 80 ℃ for 4h, adding 10.0g of beta-amylase preparation, continuously heating in water bath at 80 ℃ for 20min under stirring, adjusting the pH value to 9.5 by using 0.5mol/L phosphate buffer solution, adding 6.0g of neutral protease preparation, and heating in water bath at 80 ℃ for 40min to obtain a de-starched and protein bran liquid;
(2) adjusting the pH value of the de-starched and protein bran liquid obtained in the step (1) to 5.0 by using 0.5mol/L lactic acid aqueous solution, adding 3.0g of saccharifying enzyme preparation, heating in a water bath for 40min at 80 ℃ under stirring, centrifuging, washing precipitates for 4 times, placing in a drying oven, and drying for 16h at 80 ℃ to obtain a wheat bran polysaccharide crude product;
(3) adding 300mL of water into the wheat bran polysaccharide crude product obtained in the step (2), heating in a water bath at 80 ℃ for 40min, centrifuging, taking 500mL of supernatant, adding 1000mL of ethanol solution with volume fraction of 85%, ultrasonically extracting for 80min under the ultrasonic power of 400W, centrifuging, precipitating at 80 ℃, and drying for 16h to obtain 22.9g of wheat bran polysaccharide 2 #.
Through phloroglucinol method detection, the purity of the wheat bran polysaccharide obtained in the embodiment of the invention is 77.2%, and the extraction rate is 88.4%.
Method for extracting wheat bran polysaccharides in example 3
(1) Grinding 100g of wheat bran, sieving with a 60-mesh sieve, heating and inactivating at 121 ℃ for 15min, adding 2L of distilled water, heating in a water bath at 60 ℃ for 6h, adding 15.0g of peak amylase preparation, continuously heating in a water bath at 60 ℃ for 40min under stirring, adjusting the pH value to 8.5 by using 1.0mol/L potassium dihydrogen phosphate aqueous solution, adding 10.0g of neutral protease preparation, and heating in a water bath at 60 ℃ for 60min to obtain a de-starched and protein bran liquid;
(2) adjusting the pH value of the de-starched and protein bran liquid obtained in the step (1) to 4.0 by using 1.0mol/L citric acid aqueous solution, adding 5.0g of saccharifying enzyme preparation, heating in a water bath for 60min at 60 ℃ under stirring, centrifuging, washing the precipitate for 3 times, placing in a drying oven, and drying for 24h at 60 ℃ to obtain a wheat bran polysaccharide crude product;
(3) adding 500mL of water into the wheat bran polysaccharide crude product obtained in the step (2), heating in a water bath at 60 ℃ for 50min, centrifuging, taking 500mL of supernatant, adding 1500mL of ethanol solution with 90% volume fraction, performing ultrasonic extraction for 30min under the ultrasonic power of 500W, centrifuging, precipitating at 60 ℃, and drying for 24h to obtain 23.8g of wheat bran polysaccharide # 3.
Through phloroglucinol method detection, the purity of the wheat bran polysaccharide obtained in the embodiment of the invention is 78.5%, and the extraction rate is 93.4%.
Rice noodle examples 1-3 and comparative example 1
The weight parts of the raw materials in the rice noodle examples 1-3 and the comparative example 1 are shown in Table 1.
TABLE 1 tables of weight parts of respective raw materials in examples 1 to 3 and comparative example 1 of rice noodles
Note: in the table, "-" indicates no addition.
In example 1, the particle sizes of the japonica rice flour and the long-shaped rice flour are both 80 meshes; in comparative example 1 and example 2, the particle sizes of the japonica rice flour and the long-shaped rice flour are both 90 meshes; in example 3, the particle sizes of the japonica rice flour and the long-shaped rice flour are both 100 meshes.
Method for producing rice noodles in example 1
Mixing round-grained rice flour and long-grained rice flour uniformly according to the weight parts of the raw materials in the example 1 in the table 1, adding corn starch and wheat bran polysaccharide No. 1, adding water, mixing into a wet flour block, steaming with boiling water for 20min, pouring the steamed rice flour block into a rice noodle forming machine with an outlet aperture of 2.0mm while the rice flour block is hot, extruding and milling, cutting off extruded noodles at the position of 0.5m in length, quickly cooling in 15 ℃ cold water, steaming the cooled noodles for 10min with boiling water, taking out, rinsing with 15 ℃ cold water, rubbing loose, draining, hanging in the shade and drying to obtain the rice noodle 1.
The rice noodle obtained in the embodiment of the invention has the rehydration time of 4.5min and the rehydration rate of 2.35 by the detection of QB/T2652-2004 instant rice noodle (rice noodle) method, which shows that the structure of the rice noodle obtained in the embodiment of the invention is protected to a certain extent and can be recovered to the original state more quickly.
The broken rate of the rice noodles obtained in the embodiment of the invention is 6.74% through the detection of a QB/T2652-2004 instant rice noodle (rice noodle) method, which shows that the rice noodles obtained in the embodiment of the invention have good chewiness.
Method for producing rice noodles, example 2
Mixing round-grained rice flour and long-grained rice flour uniformly according to the weight parts of the raw materials in the embodiment 2 in the table 1, adding corn starch and wheat bran polysaccharide No. 2, adding water, mixing into a wet flour block, steaming with boiling water for 30min in a water-proof way, pouring the steamed rice flour block into a rice noodle forming machine with an outlet aperture of 2.5mm while the rice flour block is hot, extruding and milling, cutting off extruded noodles at the position of 0.6m in length, quickly cooling in cold water at 20 ℃, steaming the cooled noodles for 15min in the water-proof way with boiling water, taking out, rinsing with the cold water at 20 ℃, rubbing loose, draining, hanging in the shade and drying to obtain the rice noodle 2.
The rice noodle obtained in the embodiment of the invention has the rehydration time of 4.0min and the rehydration rate of 2.72 by the detection of QB/T2652-2004 instant rice noodle (rice noodle) method, which shows that the structure of the rice noodle obtained in the embodiment of the invention is protected to a certain extent and can be recovered to the original state more quickly.
The broken rate of the rice noodles obtained in the embodiment of the invention is 7.93 percent by the detection of QB/T2652-2004 instant rice noodles (rice noodles) method, which shows that the rice noodles obtained in the embodiment of the invention have good chewiness.
Method for producing rice noodles in example 3
Mixing round-grained rice flour and long-grained rice flour uniformly according to the weight parts of the raw materials in the embodiment 3 shown in the table 1, adding corn starch and wheat bran polysaccharide No. 3, adding water, mixing into a wet flour block, steaming with boiling water for 40min in a water-proof way, pouring the steamed rice flour block into a rice noodle forming machine with the outlet aperture of 3.0mm while the rice flour block is hot, extruding and milling, cutting off extruded vermicelli at the length of 0.7m, quickly cooling in cold water at 25 ℃, steaming the cooled vermicelli with boiling water for 20min in a water-proof way, taking out, rinsing with the cold water at 25 ℃, rubbing loose, draining, hanging in the shade and drying to obtain the rice noodle 3.
The rice noodle obtained in the embodiment of the invention has the rehydration time of 4.0min and the rehydration rate of 2.21 by the detection of QB/T2652-2004 instant rice noodle (rice noodle) method, which shows that the structure of the rice noodle obtained in the embodiment of the invention is protected to a certain extent and can be recovered to the original state more quickly.
The broken rate of the rice noodles obtained in the embodiment of the invention is 7.68 percent through the detection of a QB/T2652-2004 instant rice noodle (rice noodle) method, which shows that the rice noodles obtained in the embodiment of the invention have good chewiness.
Method for making rice noodles comparative example 1
Mixing semen oryzae Sativae powder and semen oryzae powder, adding corn starch, adding water, mixing to obtain wet powder block, steaming with boiling water for 30min, pouring the steamed rice powder block into rice noodle forming machine with outlet aperture of 2.5mm, squeezing to obtain powder, cutting the extruded vermicelli at 0.6m length, rapidly cooling in 20 deg.C cold water, steaming with boiling water for 15min, taking out, rinsing with 20 deg.C cold water, rubbing, draining, and hanging in the shade to obtain rice noodle 4.
The rice noodle obtained in the comparative example has the rehydration time of 6.5min and the rehydration rate of 2.19 by the QB/T2652-2004 convenient rice noodle (rice noodle) method detection, which shows that the structure of the rice noodle obtained in the comparative example is damaged and is not easy to recover to the original state.
The breakage rate of the rice noodles obtained in the comparative example is 9.68% detected by a QB/T2652-2004 instant rice noodle (rice noodle) method, which indicates that the breakage rate of the rice noodles obtained in the comparative example is insufficient, and the breakage rate is caused.
In order to evaluate the sensory quality of the rice noodle pairs 1-4 obtained in the examples 1-3 and the comparative example 1, 10 sensory evaluators were selected to conduct sensory evaluation on the rice noodle samples 1-4 obtained in the examples 1-3 and the comparative example 1, and the sensory evaluation was mainly conducted on the color, appearance, palatability, toughness, viscosity, smoothness and taste values of the rice noodles, the sensory evaluation criteria are shown in table 2, and the evaluation results are shown in table 3.
TABLE 2 sensory evaluation standard table for rice noodles
TABLE 3 sensory evaluation results of rice noodles 1 to 4 obtained in examples 1 to 3 of the present invention and comparative example 1
As can be seen from Table 3, the rice noodles with wheat bran polysaccharides had better taste indexes in terms of product color, appearance, palatability, toughness, viscosity, smoothness and taste value than the rice noodles without wheat bran polysaccharides.
In order to evaluate the blood sugar lowering effect of the rice noodle pairs 1-4 obtained in the examples 1-3 and the comparative example 1 of the invention, 5 volunteers (age 18-40, BMI 18.5-23) were selected, and blood sugar before and after eating the rice noodle samples 1-4 obtained in the examples 1-3 and the comparative example 1 of the invention was measured, wherein the specific measurement method was as follows: the volunteers were not taking the medicine within one week of the test, did not eat after 8 o 'clock before the test, did not drink water before the data of the day was measured, measured fasting blood glucose at 8 o' clock in the morning, and then blood glucose after eating 30min, 60min, 90min, 120min and 150min after eating 100g of rice noodles, respectively, and did not eat any food during the period. The test results are shown in table 4.
TABLE 4 Table of blood sugar changes before and after eating the rice noodles 1 to 4 obtained in examples 1 to 3 of the present invention and comparative example 1
As can be seen from table 4, the maximum blood glucose value reached 30min after eating the rice noodles with or without wheat bran polysaccharide added thereto, but the maximum blood glucose value was much lower than the blood glucose value 30min after eating the rice noodles without wheat bran polysaccharide added thereto; with the lapse of time, after eating the rice noodle without the wheat bran polysaccharide, the blood sugar is slowly reduced after 30min, while the blood sugar is more rapidly reduced when eating the rice noodle with the wheat bran polysaccharide. Therefore, the rice noodles 1-3 in the embodiments 1-3 have better blood sugar reducing effect than the rice noodles 4 in the comparative example 1.