Preparation method of high-quality fresh and wet oat rice noodles

Abstract

The invention discloses a preparation method of high-quality fresh and wet oat rice noodles, which comprises the following steps of: fermenting early indica rice, grinding into thick liquid, mixing the thick liquid with soaked oat, grinding into thick liquid, adding a certain amount of corn starch, and mixing to obtain the high-quality fresh and wet oat rice noodles. Adding different types of edible gum in different proportions, such as curdlan, konjac gum, carrageenan, xanthan gum, guar gum and the like, and carrying out size mixing; performing one-time gelatinization forming by using a full-automatic single-screw rice flour machine after uniform size mixing, and performing aging in a constant-temperature and constant-humidity box with constant temperature and constant humidity; the aged oat rice flour enters a water bath kettle to be recooked at a constant temperature, and the recooked oat rice flour is put into a proper packaging bag without being vacuumized. And placing the packaged fresh and wet oat rice noodles in a high-temperature environment for high-temperature sterilization, and cooling to obtain the high-quality fresh and wet oat rice noodle finished product.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, and particularly relates to a method for preparing high-quality fresh wet oat rice noodles. Background Art

[0002] Rice noodles are a traditional rice product mainly made from early indica rice, mainly in strip or filament form, and have a broad market in Southeast Asia and provinces such as Hunan and Hubei in China. Rice noodles are rich in nutrition, have a smooth taste, good elasticity and toughness, and are deeply loved by consumers.

[0003] However, with the development of the times, traditional foods also need to be continuously innovated and make continuous progress towards industrialized preparation processes, rich nutritional components, diverse flavors, and convenient consumption. Oats are a coarse grain crop, containing rich elements such as protein, vitamins, and minerals, and having nutritional and health care functions. Applying nutritious oats to the production of rice noodles can improve people's dietary structure and increase the intake of nutritional components, and has good market prospects.

[0004] Currently, Chinese Patent No. CN114027437A discloses a tough fresh wet rice noodle and its preparation method, which includes indica rice, compound starch and water, and the compound starch is a combination of corn starch, tapioca starch and potato starch; the indica rice is obtained by lactic acid bacteria fermentation.

[0005] Although this tough fresh wet rice noodle and its preparation method combine the lactic acid bacteria fermentation process with a preferred compound starch formula and a re-boiling process, overcoming problems such as high breakage rate, easy adhesion, poor dispersibility, and easy soup thickening of fresh wet rice noodles, it mainly uses the fermentation method of lactic acid bacteria. Since the amylose content of oats is lower than that of ordinary rice, it is difficult to form a gel structure with higher strength, and it does not have viscoelasticity itself. Therefore, the fresh wet rice noodles made with a high content of oats have problems such as high cooking loss rate and high breakage rate. Summary of the Invention

[0006] An object of the present invention is to provide a method for preparing high-quality fresh wet oat rice noodles, which has the advantages of adding edible gums such as curdlan gum, konjac gum, carrageenan, xanthan gum, guar gum, etc. into the fresh wet oat rice noodles, so that the prepared fresh wet oat rice noodles have higher strength and hardness, better elasticity and toughness, lower cooking loss and breakage rate, good taste, and can effectively maintain the unique flavor and nutritional value of oats.

[0007] The above technical object of the present invention is achieved through the following technical solutions: A method for preparing high-quality fresh wet oat rice noodles includes the following steps: S1. After cleaning, early indica rice is fermented with water at a weight ratio of 1: (1 - 2) for 48 h - 96 h, and after cleaning, oats are soaked with water at a weight ratio of 1: (1 - 2) for 1 h - 5 h; S2. Take the early indica rice and oats in step S1, mix the two according to the weight ratio of 50% - 95% of early indica rice and 50% - 5% of oats, and grind them into slurry; then add starch for mixing, and add edible glue for sizing after mixing. The obtained slurry is extruded and formed into rice noodles by a full-automatic rice noodle machine; among them, the mixed quality of early indica rice and oats (dry basis): the quality of starch is (10 - 20):1; the mixed quality of early indica rice and oats (dry basis): the quality of edible glue is (10 - 100):1; S3. Age the oat rice noodles obtained in step S2 in an environment with a constant temperature and constant humidity; S4. Boil the oat rice noodles obtained in step S3 in boiling water, then cool and package them, and obtain the finished product of fresh and wet oat rice noodles after high-temperature sterilization.

[0008] Through the above technical solution, a preparation method of fresh and wet oat rice noodles is provided. The whole method includes steps such as early indica rice being fermented, ground into slurry, mixed, gelatinized, extruded and formed, then aged, rehydrated, cooled, packaged, and high-temperature sterilized. The fermentation temperature of early indica rice is 25°C, and the fermentation time is 48 hours - 96 hours. The soaking temperature of oats is 25°C, and the soaking time is 1 h - 5 h. The mass ratio of the dry rice and oat mixture to water during grinding into slurry is (2 - 4):1. Add edible glue to the rice slurry, and control the mass ratio of the dry rice and oat mixture to the edible glue to be (100 - 20):1. Extrusion and forming are carried out by a full-automatic rice noodle machine. The gelatinization temperature is 100°C - 110°C, and the gelatinization time is 2 min - 5 min. The aging conditions of the rice noodles are that the aging humidity is between 50% - 90%, and the aging time is 2 h - 8 h. The re-boiling process is carried out in a constant temperature water bath pot at 80°C - 100°C, and the re-boiling time is 1 min - 10 min. High-temperature sterilization is to keep the packaged fresh and wet rice noodles in a water bath environment at 80°C - 100°C for 20 min - 30 min and then cool. In fact, in addition to the above preparation method, the present application also provides a method for improving the cooking quality of fresh and wet oat rice noodles to obtain high-quality fresh and wet oat rice noodles. After fermenting the rice, grind it into slurry, add 1% - 10% of edible glue such as curdlan, konjac gum, carrageenan, xanthan gum, guar gum, etc., one or several of them for mixing, and after extrusion and forming, obtain fresh and wet oat rice noodles with high cooking quality and sensory quality through aging, re-boiling, and sterilization.

[0009] Further setting: Step S1 is specifically as follows: After cleaning, early indica rice is fermented with water at a temperature of 25°C - 35°C, drained, and after cleaning, oats are soaked with water at a temperature of 25°C - 35°C, drained.

[0010] Further setting: In the step S2, the starch includes one or several of corn starch, sweet potato starch, cassava starch, mung bean starch, wheat starch, etc.

[0011] Further setting: In the step S2, the edible gum includes one or several of curdlan, konjac gum, carrageenan, xanthan gum, guar gum, etc.

[0012] Further setting: In the step S3, the aging under constant temperature and constant humidity includes controlling the temperature at 10 - 30 °C, the humidity at 50% - 90%, and the aging time at 2 - 10 h.

[0013] Further setting: In the step S4, the re - boiling time is 1 min - 5 min, the high - temperature sterilization temperature is 70 °C - 95 °C, and the high - temperature sterilization time is 10 min - 45 min.

[0014] In summary, the present invention has the following beneficial effects: 1. The present invention replaces the traditional water - cooling aging process in industry with the method of aging under constant temperature and constant humidity, effectively reducing the waste of water resources and avoiding the trouble brought by a large amount of wastewater treatment. Moreover, the aging under constant temperature and constant humidity makes the product more stable, with greater strength and less prone to breaking.

[0015] 2. The present invention adopts the re - boiling process, which can not only quickly re - hydrate the aged rice noodles, achieve the high water content of fresh - wet rice noodles, improve the taste of the rice noodles, but also effectively improve the dispersibility of the rice noodles, enabling the rice noodles to quickly disperse in water without sticking.

[0016] 3. The shelf life of the fresh - wet oat rice noodles treated by high - temperature sterilization in the present invention is 30 - 60 days. By using a mild sterilization technology and a method of not adding preservatives, the microorganisms inside the fresh - wet rice noodles and on the packaging are killed, extending the shelf life of the fresh - wet oat rice noodles.

[0017] 4. The present invention provides a fresh - wet oat rice noodle product, enriching the product forms of oat products and promoting the deep processing of oats. The fresh - wet rice noodles prepared from oats not only have the unique flavor of oats but also are rich in nutritional components.

[0018] 5. By adding edible gum to the fresh - wet oat rice noodles, the present invention makes the structure of the fresh - wet oat rice noodles more stable, with greater strength, reduced cooking loss and breaking rate, and improved sensory quality and cooking quality. Detailed implementation manners

[0019] The following further explains the detailed implementation manners of the present invention.

[0020] The technical solution adopted by the present invention is: Example 1: (1) The cleaned early indica rice and water were fermented at a weight ratio of 1:1.5 at room temperature of 25 °C for 48 h, and the cleaned oats and water were soaked at a weight ratio of 1:1.5 at room temperature of 25 °C for 2 h.

[0021] (2) After cleaning and draining, they were mixed according to the weight ratio of 50% early indica rice and 50% oats. According to the mass ratio of the mixture of early indica rice and oats to water of 1.5:1, clear water was added. After grinding with an automatic pulping machine, 10% corn starch was added to adjust the pulp, and 2% curdlan was added and stirred evenly. The obtained pulp was extruded and formed with a single-stage gelatinized rice noodle machine to obtain rice noodles. (3) The oat rice noodles obtained in step (2) were aged in a constant temperature and humidity box, controlling the temperature at 20 °C, the humidity at 60%, and the aging time at 3 hours. (4) The rice noodles obtained in step (3) were boiled in boiling water for 3 min, then cooled and packaged. After sterilization at 90 °C for 30 min, the finished product of fresh wet oat rice noodles could be obtained.

[0022] The texture properties of the rice noodles were measured using a TA-XT plus type texture analyzer. The texture measurement mode was TPA, the probe was P35, and the measurement parameters were set as follows: pre-test speed 1.0 mm / s, in-test speed 1.0 mm / s, post-test speed 1.0 mm / s, compression ratio 70%, and parallel measurement times 10 times / sample.

[0023] The method for measuring the breakage rate was as follows: Take 30 rice noodles with uniform diameter and a length of about 20 cm, add 500 mL of boiling water, keep it boiling gently for 3 min, then pick out the rice noodles, record the number of broken rice noodles n, and calculate the breakage rate L according to the following formula: ;

[0024] The method for measuring the cooking loss: Weigh a sample with intact vermicelli, record the sample mass M0, and measure the moisture content W. Put the sample into a tray with a constant weight of M1 containing 500 mL of boiling water and boil for 3 min. After fishing out the rice noodles, the tray was placed on an electric furnace and heated continuously. After most of the water was boiled dry, it was dried to a constant weight in an oven at 105 °C, and the recorded mass was M2. Calculate the cooking loss according to the following formula: ;

[0025] The method for determining starch digestibility is as follows: Weigh 0.6 g (dry basis) of starch into a 50 mL centrifuge tube, add 5 mL of 0.25 M (pH 5.2) sodium acetate buffer, and gelatinize in a boiling water bath for 30 min. Preheat in a water bath shaker at 37°C and 160 rpm for 10 min, add 50 mg of guar gum and 20 glass beads (D 5 - 6 mm); start timing, add 10 mL of pepsin to one centrifuge tube every minute to ensure consistent reaction time; after the samples in each tube have reacted for 30 min, add 5 mL of sodium acetate buffer (pH 5.2) in sequence and continue the reaction for 30 min; during this period, take 0.125 mL of the sample solution at 0 min and inactivate the enzyme in 66.6% ethanol; centrifuge the inactivated sample at 3500 rpm for 5 min, and the supernatant is to be measured. After the gastric phase reaction is completed, immediately add 5 mL of mixed enzymes in sequence; and at 10, 20, 30, 60, 90, 120, and 180 min, respectively, take 0.125 mL of the sample and inactivate the enzyme in 5 mL of 66.6% ethanol; centrifuge the inactivated sample at 3500 rpm for 5 min, and the supernatant is to be measured. Accurately pipette 0.05 mL of the sample supernatant, deionized water, and the standard product and mix them with 1.5 mL of the chromogenic solution (Leadman GOPOD kit) respectively; react in a water bath shaker at 37°C for 10 min and measure the absorbance at a wavelength of 520 nm. Usually, 3 parallels are made.

[0026] Calculation formula: Concentration of glucose standard product (mmol / L): It depends on the concentration of the standard product provided by the kit, such as 5.46; Concentration of glucose standard product (mg / L): 5.46 × 180 = 0.9828; G = (A - A0) × 0.9828 × 40 × 25 / Ast / m; A: Absorbance of the sample; A0: Absorbance of the blank; Ast: Absorbance of the standard product; m: Mass of the sample.

[0027] 。

[0028] Example 2: Refer to Example 1 to prepare fresh wet oat rice flour, with the difference that different addition amounts of oats are added for mixing, and other conditions are the same as in Example 1. The addition amounts of oats are 30%, 40%, 50%, 60%, and 70% respectively, and commercially available ordinary rice flour is used as a control. The texture properties of the fresh wet oat rice flour are measured according to the following method: Table 1 Effects of different addition amounts of oats on the texture properties of fresh wet oat rice flour

[0029] The results show that, compared with commercially available ordinary rice flour, when the oat content in fresh wet oat rice flour is less than 50%, its hardness and chewiness are not much different from those of the control group. The rice flour has good strength, chewiness, and a good taste. When the oat addition exceeds 50%, its hardness and chewiness decrease significantly. At this time, the fresh wet oat rice flour has low strength, no chewiness, and a poor taste. Therefore, the optimal oat addition should be below 50%.

[0030] Effect of Different Oat Additions on Cooking Quality and Digestibility of Fresh Wet Oat Rice Flour Refer to Example 1 to prepare fresh wet oat rice flour, with the difference that different amounts of oats are added for mixing, and other conditions are the same as in Example 1. The oat addition amounts are 30%, 40%, 50%, 60%, and 70% respectively, with commercially available ordinary rice flour as the control.

[0031] The determination steps of the cooking quality and digestibility of fresh wet oat rice flour are carried out according to the above method.

[0032] Table 2 Effect of Different Oat Additions on Cooking Quality and Digestibility of Fresh Wet Oat Rice Flour

[0033] The results show that, compared with commercially available ordinary rice flour, when the oat addition in fresh wet oat rice flour is less than 50%, its cooking loss and breaking rate are lower, not much different from those of commercially available ordinary rice flour, and the cooking quality is better. The rice flour does not become pasty or break during cooking; when the oat addition exceeds 50%, its cooking loss and breaking rate increase significantly, the cooking quality deteriorates, and it is prone to becoming pasty and breaking. In addition, from the perspective of starch digestibility, compared with commercially available ordinary rice flour, the starch digestibility of fresh wet rice flour with added oats is significantly reduced, which is more beneficial to people's health.

[0034] Effect of Different Processes on the Quality of Fresh Wet Oat Rice Flour

[0035] Refer to Example 1 to prepare fresh wet rice flour, with the difference that different process conditions are used. The specific process conditions are as follows: Experimental Group A: (1) Ferment the cleaned early indica rice and water at a weight ratio of 1:1.5 at room temperature of 25°C for 48 h, and soak the cleaned oats and water at a weight ratio of 1:1.5 at room temperature of 25°C for 2 h.

[0036] (2) After cleaning and draining, mix them in a weight ratio of 50% early indica rice and 50% oats. According to the mass ratio of the mixture of early indica rice and oats to water of 1.5:1, add clear water. After grinding with an automatic pulp grinder, add 10% corn starch to adjust the pulp, stir evenly, and extrude the obtained pulp with a single-stage gelatinized rice flour machine to obtain rice flour. (3) Place the oat rice flour obtained in step (2) in a thermostatic and humid box for aging, control the temperature at 20 °C, the humidity at 60%, and the aging time at 3 hours; (4) Boil the rice flour obtained in step (3) in boiling water for 3 min, then cool and package it. After sterilization at 90 °C for 30 min, the finished product of fresh wet oat rice flour can be obtained.

[0037] Experimental group B: Referring to experimental group A, the aging temperature in step (3) is 30 °C, the humidity is 80%, the aging time is 3 h, and other conditions are the same as those in experimental group A.

[0038] Experimental group C: Referring to experimental group A, the aging temperature in step (3) is 20 °C, the humidity is 60%, the aging time is 1 h, and other conditions are the same as those in experimental group A.

[0039] Experimental group D: Referring to experimental group A, the re-boiling time in step (4) is changed to 5 min, and other conditions are the same as those in experimental group A.

[0040] Commercially available ordinary fresh wet rice flour is used as the control group.

[0041] The texture properties and cooking properties are measured according to the above method.

[0042] Table 3 Comparison of the quality of fresh wet oat rice flour prepared by different processes

[0043] The results show that compared with the commercially available ordinary rice flour, the fresh wet oat rice flour prepared according to the processes described in experimental groups A, B, C, and D has similar hardness, cooking loss, and breaking rate. Moreover, the fresh wet oat rice flour prepared by the process described in experimental group A has higher hardness, lower cooking loss, and lower breaking rate than the commercially available rice flour, indicating that the fresh wet oat rice flour prepared by this process has better strength, chewiness, and cooking quality.

[0044] In this comparative example, only the addition of corn starch for slurry preparation is omitted, and other steps are the same as those in Example 2. The specific operation steps are as follows: Experimental group A: Adjust the oat content to 30%, the early indica rice content to 70%, the addition amount of gellan gum to 2%, and no corn starch is added.

[0045] Experimental group B: Adjust the oat content to 50%, the early indica rice content to 50%, the addition amount of gellan gum to 2%, and no corn starch is added.

[0046] Experimental group C: Adjust the oat content to 70%, the early indica rice content to 30%, the addition amount of gellan gum to 2%, and no corn starch is added.

[0047] Table 4 Comparison of the quality of fresh wet oat rice flour without adding corn starch

[0048] Comparing the data in Table 4 with that in the examples, the results show that for the fresh wet oat rice noodles without adding corn starch, the hardness slightly decreases, the cooking loss and the breaking rate significantly increase, and the comprehensive quality of the rice noodles decreases. Comparative Example 2

[0049] In this comparative example, only adding edible glue for slurry preparation is omitted, and other steps are the same as those in Example 2. The specific operation steps are as follows: Experimental group D: Adjust the oat content to 30%, the early indica rice content to 70%, add 10% corn starch for slurry preparation, and do not add edible glue.

[0050] Experimental group E: Adjust the oat content to 50%, the early indica rice content to 50%, add 10% corn starch for slurry preparation, and do not add edible glue.

[0051] Experimental group F: Adjust the oat content to 70%, the early indica rice content to 30%, add 10% corn starch for slurry preparation, and do not add edible glue.

[0052] Table 5 Comparison of the quality of fresh wet oat rice noodles without adding edible glue

[0053] Comparing the data in Table 5 with that in the examples, the results show that for the fresh wet oat rice noodles without adding edible glue, the hardness decreases, the cooking loss and the breaking rate significantly increase, and the comprehensive quality of the rice noodles significantly decreases. Comparative Example 3

[0054] In this comparative example, only the type of edible glue is changed for slurry preparation, and other steps are the same as those in Example 1. The specific operation steps are as follows: Experimental group G: Adjust the oat content to 50%, the early indica rice content to 50%, add 10% corn starch for slurry preparation, and add 2% konjac gum.

[0055] Experimental group H: Adjust the oat content to 50%, the early indica rice content to 50%, add 10% corn starch for slurry preparation, and add 2% carrageenan.

[0056] Experimental group I: Adjust the oat content to 50%, the early indica rice content to 50%, add 10% corn starch for slurry preparation, and add 2% xanthan gum.

[0057] Experimental group J: Adjust the oat content to 50%, the early indica rice content to 50%, add 10% corn starch for slurry preparation, and add 2% guar gum.

[0058] Table 6 Comparison of the quality of fresh wet oat rice noodles with different types of edible glue added

[0059] Comparing the data in Table 6 and the examples, the results show that there is little difference in the hardness of the fresh and wet oat rice flour added with different types of edible gums. The cooking loss and the broken strip rate are also not much different. The comprehensive quality of the rice flour has been improved, but the curdlan in the examples has the best effect. Comparative Example 4

[0060] In this comparative example, the type of additive was changed, and the slurry was adjusted with common rice and flour additives. Other steps were the same as those in Example 1. The specific operation steps are as follows: Experimental group K: Adjust the oat content to 50%, the early indica rice content to 50%, add 10% corn starch for slurry adjustment, and add 2% hydroxypropyl starch.

[0061] Experimental group L: Adjust the oat content to 50%, the early indica rice content to 50%, add 10% corn starch for slurry adjustment, and add 2% acetate starch Experimental group M: Adjust the oat content to 50%, the early indica rice content to 50%, add 10% corn starch for slurry adjustment, and add 2% soy lecithin.

[0062] Table 6 Comparison of the quality of fresh and wet oat rice flour added with different types of additives

[0063] Comparing the data in Table 6 and the examples, the results show that compared with the examples, the hardness of the fresh and wet oat rice flour added with different types of additives in the comparative examples has decreased, the cooking loss and the broken strip rate have also increased, and the comprehensive quality of the rice flour has decreased.

[0064] From the data of the above examples and comparative examples, it can be seen that: through the compounding of oats, early indica rice, and starch, the optimization of the aging conditions, and the method of adding edible gums, the present invention solves the objective problems such as the low hardness, easy broken strips, and large cooking loss of fresh and wet oat rice flour. The present invention adopts constant temperature and humidity aging, which greatly saves the production cost, and the quality of the rice flour is also better, overcoming the problems such as large energy consumption, high cost, and easy microbial contamination of the rice flour brought by traditional high temperature and high humidity or water cooling aging methods. Moreover, the fresh and wet oat rice flour retains the nutritional value of oats to the greatest extent, has a low digestibility, and is more beneficial to people's physical health. The fresh and wet oat rice flour prepared by the present invention has the characteristics of being nutritious and healthy, smooth and chewy, and low in cost.

[0065] The above are the preferred embodiments of the present invention, and it is not intended to limit the present invention in any form. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the invention.

Claims

1. A method for preparing high-quality fresh wet oatmeal rice flour, characterized in that: The following steps are involved: S1, early indica rice after washing and fermenting with water at a weight ratio of 1: (1-2) for 48 h-96 h, oats after washing and soaking with water at a weight ratio of 1: ((1-2) for 1 h-5 h; S2, taking the early indica rice and oats in step S1, mixing the two according to the weight ratio of 50%-95% of early indica rice and 50%-5% of oats, and grinding; adding starch to mix, adding edible glue to mix after mixing, and extruding the obtained slurry with a full-automatic rice noodle machine to obtain rice noodles; wherein, the mixed mass of early indica rice and oats (on a dry basis): the mass of starch is (10-20): 1; the mixed mass of early indica rice and oats (on a dry basis): the mass of edible glue is (10-100): 1; S3, controlling the oatmeal rice flour obtained in step S2 to age in an environment of constant temperature and constant humidity; S4, the oatmeal rice flour obtained in step S3 is boiled in boiling water, cooled, and packaged, and a fresh wet oatmeal rice flour finished product can be obtained after high-temperature sterilization.

2. The method for preparing high-quality fresh wet oatmeal rice flour according to claim 1, characterized in that: The step S1 specifically comprises: fermenting the washed early indica rice with water at a temperature of 25° C.-35° C. and draining; soaking the washed oats with water at a temperature of 25° C.-35° C. and draining.

3. The method for preparing high-quality fresh wet oatmeal rice flour according to claim 2, characterized in that: In step S2, the starch includes one or more of corn starch, sweet potato starch, cassava starch, mung bean starch and wheat starch.

4. The method for preparing high-quality fresh wet oatmeal rice flour according to claim 3, characterized in that: In step S2, the edible gum includes one or more of curdlan, konjac gum, carrageenan, xanthan gum and guar gum.

5. The method for preparing high-quality fresh wet oatmeal rice flour according to claim 4, characterized in that: In step S3, the constant temperature and constant humidity aging includes controlling the temperature to be 10-30° C., the humidity to be 50%-90%, and the aging time to be 2-10 h.

6. The method for preparing high-quality fresh wet oatmeal rice flour according to claim 5, characterized in that: In the step S4, the re-boiling time is 1 min to 5 min, the high temperature sterilization temperature is 70° C. to 95° C., and the high temperature sterilization time is 10 min to 45 min.

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