A method for preparing pre-cooked brown rice by ultrasonic combined with hydrothermal treatment

Abstract

The application discloses a method for preparing pre-prepared brown rice by ultrasonic and hydrothermal treatment, and the method comprises the following basic steps: cleaning and removing impurities from brown rice, and then soaking; performing ultrasonic treatment on the soaked brown rice to generate cracks and micropores on the surface of the brown rice; performing hydrothermal treatment on the ultrasonic-treated brown rice to soften the brown rice skin layer; and drying the hydrothermal-treated brown rice after draining; the method can improve the water absorption capacity of the brown rice and improve the rough taste of the brown rice by performing ultrasonic-hydrothermal cycle treatment on the brown rice, the method does not need to perform defatting treatment on the brown rice in advance, does not need to use any chemical reagent, does not use expensive equipment, and only uses a pure physical method, so that the stickiness and taste of the brown rice can be obviously improved, and the consumer acceptance of the brown rice can be improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of food processing, and particularly relates to a method for preparing pre-prepared brown rice through ultrasonic combined with hydrothermal treatment. BACKGROUND

[0002] More than half of the world's population relies on rice as their staple food, and the main form of rice consumption is polished rice. However, the problem of nutrient loss and energy waste caused by excessive processing of polished rice is increasingly concerned. As a whole grain food, brown rice is rich in dietary fiber, vitamins, minerals, beta-glucan, arabinoxylan, gamma-oryzanol and gamma-aminobutyric acid and other health factors. At the same time, as a rations, the digestion rate of brown rice is lower than that of polished rice, which can slow down the rapid rise of postprandial blood glucose and reduce the risk of type II diabetes. However, due to the presence of the brown rice skin layer, it is difficult for water to penetrate into the interior of the rice kernel during cooking, and the brown rice rice has a hard and non-sticky taste and poor digestibility. Therefore, the consumer acceptance of brown rice is far lower than that of polished rice, which is an obstacle that must be overcome for the development of brown rice as a staple food. Developing new processing technologies that can significantly improve the eating quality of brown rice is the future direction of brown rice product development.

[0003] In order to improve the consumer acceptance of brown rice, various beneficial attempts have been made in the prior art. Germination has been proven to improve the palatability of brown rice and is beneficial to the enrichment of bioactive substances such as gamma-aminobutyric acid. For example, Chinese patent CN104351660A discloses a method for preparing high-gamma-aminobutyric acid germinated brown rice and selenium-enriched germinated brown rice, but the germination time is relatively long and may be accompanied by the generation of unpleasant odor. Cellulase treatment has been confirmed to increase the water absorption capacity of rice kernels. For example, Chinese patent CN106819852A discloses a method for improving the taste of brown rice / germinated brown rice, but the enzyme needs to be inactivated after treatment, especially the cost of the enzyme is high, which makes it difficult to realize large-scale production and popularization and application. In addition, cold plasma treatment can significantly reduce the hardness of rice and extend the shelf life of brown rice. For example, Chinese patent CN111657421A discloses the application of a method for treating rice by cold plasma in improving the quality of rice, but the equipment is expensive and the cost is high.

[0004] Moreover, the above methods mainly focus on improving the hardness and chewiness of brown rice, but have little effect on improving the stickiness of brown rice. It is still necessary to develop and research green and pollution-free physical processing technology to obtain high-quality pre-prepared brown rice, which can greatly improve the stickiness of brown rice and improve the eating quality of brown rice. SUMMARY

[0005] To address the aforementioned technical problems, this invention provides a method for preparing pre-processed brown rice using a combination of ultrasonic and hydrothermal treatment. This method employs a green and pollution-free purely physical processing technique to obtain high-quality pre-processed brown rice without using any enzymes or chemical reagents. Through conventional cooking, brown rice with a moderate texture and good palatability can be obtained, and the stickiness of the brown rice is significantly improved, thereby enhancing the public's acceptance of brown rice.

[0006] The technical solution adopted in this invention is as follows:

[0007] This invention provides a method for preparing pre-processed brown rice by a combination of ultrasonic and hydrothermal treatment, the method comprising the following steps:

[0008] (1) Clean and remove impurities from the brown rice, then soak it;

[0009] (2) Soaked brown rice was subjected to ultrasonic treatment;

[0010] (3) The brown rice processed in the previous step is subjected to water bath heating treatment;

[0011] (4) Take out the brown rice processed in the previous step, wash it with water, drain it, and then dry it to obtain pre-processed brown rice.

[0012] Furthermore, step (4) is followed by step (5). Step (5) is as follows: the dried brown rice is soaked in water again, and steps (2) and / or (3) are repeated. Then the treated brown rice is drained and dried to obtain pre-processed brown rice.

[0013] The present invention also provides a method for preparing pre-processed brown rice by ultrasonic combined hydrothermal treatment, the method comprising the following steps: first performing steps (1)(3)(4), then soaking the dried brown rice in water again, and repeating the treatment once more in the order and method described in (2)(3)(4) to obtain pre-processed brown rice.

[0014] The present invention also provides a method for preparing pre-processed brown rice by ultrasonic combined hydrothermal treatment. The method includes the following steps: first performing steps (1)(2)(4), then soaking the dried brown rice in water again, and repeating the treatment once more in the order and method described in (2)(3)(4) to obtain pre-processed brown rice.

[0015] In step (1), after removing abnormal rice grains and impurities, there is no need to perform degreasing treatment beforehand. Soak directly in room temperature water for 15-60 minutes.

[0016] In step (2), ultrasonic treatment is performed for 15-60 minutes at a frequency of 20KHz, a power of 100W, and a set temperature of 25℃.

[0017] In step (3), no chemical reagent is added, and the treated brown rice is directly heated in a water bath at 80℃ for 30 min.

[0018] In step (4), the treated brown rice is washed with clean water for 3 times and then dried.

[0019] In step (4), the drying temperature is 25-35℃, and the drying time is 5-10 h.

[0020] The application also provides the whole-grain pre-prepared brown rice prepared by the ultrasonic and hydrothermal treatment, and the hardness of the brown rice after cooking is 11-16 N, the viscosity is 0.3-1.5 N, the viscosity-hardness ratio is 0.02-0.15, and the chewiness is 3.5-6.5 N.

[0021] The application provides the method for preparing the pre-prepared brown rice by the ultrasonic and hydrothermal treatment, the cavitation effect of the ultrasonic wave is used to make cracks and micropores on the surface of the rice, when the ultrasonic wave passes through the soaking liquid of the brown rice, a large number of small bubbles are generated due to the cavitation effect, the high temperature, high pressure, strong shear and mechanical force caused by the rupture of the small bubbles can change the structure and properties of the brown rice, cracks and micropores are generated, and the water absorption channels in the starch are increased; on the other hand, the water bath heating treatment is used to soften the rough feeling on the surface of the brown rice, so that the water absorption is promoted and the taste is improved. In order to enhance the improvement effect on the quality of the brown rice, the ultrasonic and water bath heating treatment are repeated once, and the high-quality whole-grain pre-prepared brown rice can be obtained after drying. By conventional cooking, the brown rice with moderate hardness and good palatability is obtained, the viscosity of the brown rice is greatly improved compared with that before the treatment, and the acceptability of the popular consumption of the brown rice is improved.

[0022] Compared with the prior art, the application has the following advantages:

[0023] 1. The preparation method of the pre-prepared brown rice provided by the application has the advantages of green, safety, no pollution, no use of any chemical reagent and high-value instrument, and high efficiency, and can realize large-scale industrial application.

[0024] 2. The pre-prepared brown rice prepared by the application is not only green, safe and sanitary, but also has the following advantages: after the ultrasonic and water bath heating treatment, the surface skin structure of the brown rice is cracked and the micropores are increased, the rough feeling is softened, the water absorption is obviously improved, the taste is improved, the cooking time is short, the viscosity of the cooked brown rice is high, the hardness is moderate, and the palatability and digestibility are improved.

[0025] 3. The application has the advantages of simple process, short treatment time and low production cost, can meet the demand of consumers for green and healthy whole-grain brown rice, and has very broad market prospect. DETAILED DESCRIPTION

[0026] The application provides a method for preparing pre-prepared brown rice by ultrasonic combined hydrothermal treatment, and the steps are as follows:

[0027] (1) After removing abnormal rice grains and sundries, no defatting treatment is needed, and the brown rice is directly soaked in room temperature water for 15-60 min;

[0028] (2) The brown rice soaked in water is treated by ultrasonic at a frequency of 20 KHz, a power of 100 W and a set temperature of 25 DEG C for 15-60 min;

[0029] (3) The brown rice treated in the previous step is directly heated in a water bath at 80 DEG C for 30 min without adding any chemical reagent;

[0030] (4) The treated brown rice is taken out, washed with clean water for 3 times and then drained, and then dried; the drying temperature is 25-35 DEG C, the drying time is 5-10 h, and the pre-prepared brown rice is prepared by drying to the original water content.

[0031] Further, the step (4) is further provided with a step (5), that is, the dried brown rice is soaked in water again, the steps (2) and / or (3) are repeated, then the treated brown rice is drained and dried to prepare the pre-prepared brown rice.

[0032] The method for preparing the pre-prepared brown rice by ultrasonic combined hydrothermal treatment can be replaced by the following steps: the steps (1), (3) and (4) are first performed, then the dried brown rice is soaked in water again, and the steps (2), (3) and (4) are repeated once in the order and method to prepare the pre-prepared brown rice.

[0033] The method for preparing the pre-prepared brown rice by ultrasonic combined hydrothermal treatment can be replaced by the following steps: the steps (1), (2) and (4) are first performed, then the dried brown rice is soaked in water again, and the steps (2), (3) and (4) are repeated once in the order and method to prepare the pre-prepared brown rice.

[0034] The application evaluates the edible quality of brown rice by the texture of rice, and focuses on the improvement of hardness, chewiness, stickiness and stickiness-hardness ratio of brown rice. After being treated under appropriate conditions, the texture of brown rice is obviously improved, the hardness and chewiness are obviously reduced, the stickiness and stickiness-hardness ratio are greatly improved, and the palatability is obviously improved.

[0035] The cooking method of untreated brown rice or pre-prepared brown rice is as follows: water is added according to the rice-water ratio of 1:1.0, heated and cooked under airtight condition for 20 min, and kept warm for 20 min to prepare brown rice.

[0036] Method for measuring the texture of brown rice: After the freshly steamed brown rice is cooled in a 25℃ constant temperature incubator for 90 min, 30 intact rice grains from the middle layer are used to measure the texture with a texture analyzer, and then the average value of the test results is obtained. The texture measurement conditions are as follows: a 5kg sensor, a 25mm cylindrical probe, a compression rate of 90%, a contact force of 5g, a working distance of 25mm, a pre-measurement, measurement and post-measurement speed of 1.0mm / s, and a 4s interval between two compressions.

[0037] The application will be described in detail below with reference to the comparative examples and examples.

[0038] Comparative Example 1

[0039] The non-waxy japonica brown rice raw material or milled rice raw material is not treated, water is added at a rice-water ratio of 1g:1.0mL, heated and cooked under airtight conditions for 20min, and kept warm for 20min to obtain brown rice.

[0040] The brown rice prepared in Comparative Example 1 is subjected to texture measurement, and the hardness is 16.824N, the viscosity is 0.126N, the viscosity-hardness ratio is 0.007, and the chewiness is 7.902N. The texture parameters of milled white rice are as follows: the hardness is 13.232N, the viscosity is 1.901N, the viscosity-hardness ratio is 0.144, and the chewiness is 5.657N. It can be seen that the hardness and chewiness of the untreated control group brown rice are higher than those of milled white rice, the viscosity and viscosity-hardness ratio are lower, the taste is poorer, the palatability is not good, and it is not easy to chew.

[0041] Example 1

[0042] A method for preparing a pre-prepared brown rice, the steps of which are as follows:

[0043] (1) After removing abnormal rice grains and impurities, the brown rice is directly soaked in room temperature water for 30min, and the mass-volume ratio of the brown rice to water is 1g:1.5mL;

[0044] (2) Then the water-soaked brown rice is subjected to ultrasonic treatment for 30min at a frequency of 20KHz, a power of 100W and a set temperature of 25℃;

[0045] (3) The brown rice after the foregoing treatment does not need to add any chemical reagent and is directly subjected to water bath heating treatment at 80℃ for 30min;

[0046] (4) The treated brown rice is washed with clean water for 3 times, drained, and dried at 30℃ for 7h until the water content approaches that of the original brown rice to obtain a pre-prepared brown rice.

[0047] The pre-prepared brown rice is added with water at a rice-water ratio of 1g:1.0mL, heated and cooked under airtight conditions for 20min, and kept warm for 20min to obtain brown rice.

[0048] The brown rice prepared in Example 1 has a hardness of 12.961 N, a viscosity of 0.474 N, a viscosity-hardness ratio of 0.037, and a chewiness of 4.094 N as determined by texture measurement. It can be seen that the hardness and chewiness of the brown rice are significantly lower than those of the brown rice in Comparative Example 1, the viscosity and viscosity-hardness ratio are significantly higher, and the taste is improved, but the viscosity and viscosity-hardness ratio are still too different from those of the white rice. The texture parameters of the white rice are as follows: hardness of 13.232 N, viscosity of 1.901 N, viscosity-hardness ratio of 0.144, and chewiness of 5.657 N.

[0049] Comparative Example 2

[0050] Other than Example 1, no ultrasonic treatment in step (2) is performed.

[0051] The above-prepared brown rice is heated and cooked in water at a rice-to-water ratio of 1 g: 1.0 mL under airtight conditions for 20 min, and then kept for 20 min to prepare brown rice.

[0052] The brown rice prepared in Comparative Example 2 has a hardness of 14.655 N, a viscosity of 0.359 N, a viscosity-hardness ratio of 0.024, and a chewiness of 4.783 N as determined by texture measurement. It can be seen that the hardness and chewiness are higher than those of Example 1, and the viscosity and viscosity-hardness ratio are lower, and the overall quality of the brown rice is not good.

[0053] Comparative Example 3

[0054] Other than Example 1, no water bath heating treatment in step (3) is performed.

[0055] The above-prepared brown rice is heated and cooked in water at a rice-to-water ratio of 1:1.0 under airtight conditions for 20 min, and then kept for 20 min to prepare brown rice.

[0056] The brown rice prepared in Comparative Example 3 has a hardness of 14.569 N, a viscosity of 0.360 N, a viscosity-hardness ratio of 0.025, and a chewiness of 4.677 N as determined by texture measurement. It can be seen that the hardness and chewiness are similar to those of Comparative Example 2, but are higher than those of Example 1, and the viscosity and viscosity-hardness ratio are lower, and the overall quality of the brown rice is not good.

[0057] Example 2

[0058] A method for preparing a pre-prepared brown rice, the steps of which are as follows:

[0059] (1) After removing abnormal rice grains and impurities, the brown rice is directly soaked in room temperature water for 30 min without pre-fat removal treatment, and the mass-to-volume ratio of the brown rice to water is 1 g: 1.5 mL;

[0060] (2) Then, the water-soaked brown rice is ultrasonically treated at a frequency of 20 KHz, a power of 100 W, and a set temperature of 25℃ for 30 min;

[0061] (3) The ultrasonic treated brown rice is directly heated in a water bath at 80°C for 30 min without adding any chemical reagent;

[0062] (4) The heat treated brown rice is washed with clean water for 3 times, drained and dried, and then baked at 30°C for 7 h until the water content is close to the original water content of the brown rice.

[0063] (5) Then, the dried brown rice is again immersed in water, and treated according to the sequence and method described in (2) and (4) above to obtain the pre-prepared brown rice.

[0064] The pre-prepared brown rice is heated and cooked in a closed condition for 20 min with 1 g of brown rice and 1.0 mL of water, and then kept for 20 min to obtain brown rice.

[0065] The brown rice prepared in Example 2 is subjected to texture determination, and the hardness is 14.356 N, the viscosity is 0.754 N, the viscosity-hardness ratio is 0.053, and the chewiness is 5.930 N. Compared with the brown rice in Comparative Example 1, the hardness and chewiness are obviously reduced, the viscosity and viscosity-hardness ratio are obviously increased, and the taste is obviously improved. However, compared with the white rice, the viscosity and viscosity-hardness ratio still have a large difference. The texture parameters of the white rice are as follows: the hardness is 13.232 N, the viscosity is 1.901 N, the viscosity-hardness ratio is 0.144, and the chewiness is 5.657 N.

[0066] Example 3

[0067] A method for preparing pre-prepared brown rice, comprising the following steps:

[0068] (1) After removing abnormal rice grains and impurities, the brown rice is directly soaked in room temperature water for 30 min without pre-fat removal treatment, and the mass-volume ratio of the brown rice to water is 1 g: 1.5 mL;

[0069] (2) Then, the water-soaked brown rice is ultrasonically treated for 30 min at a frequency of 20 KHz, a power of 100 W, and a set temperature of 25°C;

[0070] (3) The ultrasonic treated brown rice is directly heated in a water bath at 80°C for 30 min without adding any chemical reagent;

[0071] (4) The heat treated brown rice is washed with clean water for 3 times, drained and dried, and then baked at 30°C for 7 h until the water content is close to the original water content of the brown rice.

[0072] (5) Then, the dried brown rice is again immersed in water, and treated according to the sequence and method described in (2) and (4) above to obtain the pre-prepared brown rice.

[0073] The above prepared brown rice is added with water in a mass-volume ratio of 1 g: 1.0 mL, heated and cooked under a closed condition for 20 min, and kept for 20 min to prepare brown rice.

[0074] The brown rice prepared in Example 3 is subjected to texture determination, and the hardness is 13.594 N, the viscosity is 0.456 N, the viscosity-hardness ratio is 0.034, and the chewiness is 4.794 N. Compared with the brown rice in Comparative Example 1, the hardness and chewiness are obviously reduced, and the viscosity and viscosity-hardness ratio are obviously increased, but the improvement is far less than that in Example 2. Compared with the fine white rice, the viscosity and viscosity-hardness ratio are too different. The texture parameters of the fine white rice are as follows: the hardness is 13.232 N, the viscosity is 1.901 N, the viscosity-hardness ratio is 0.144, and the chewiness is 5.657 N.

[0075] Example 4

[0076] A preparation method of a prepared brown rice, comprising the following steps:

[0077] (1) After removing abnormal rice grains and impurities, the brown rice is directly soaked in room temperature water for 30 min without pre-fat removal treatment, and the mass-volume ratio of the brown rice to water is 1 g: 1.5 mL;

[0078] (2) Then, the water-soaked brown rice is subjected to ultrasonic treatment for 30 min at a frequency of 20 KHz, a power of 100 W, and a set temperature of 25°C;

[0079] (3) The ultrasonically treated brown rice is directly subjected to water bath heating treatment at 80°C for 30 min without adding any chemical reagent;

[0080] (4) The treated brown rice is washed with water for 3 times, drained, and then dried at 30°C for 7 h until the water content approaches the original water content of the brown rice.

[0081] In the above steps, steps (1), (3), and (4) are performed first, then the dried brown rice is soaked in water again in a mass-volume ratio of 1 g: 1.5 mL, and the order and method described in (2), (3), and (4) are repeated once to prepare the prepared brown rice.

[0082] The above prepared brown rice is added with water in a mass-volume ratio of 1: 1.0, heated and cooked under a closed condition for 20 min, and kept for 20 min to prepare brown rice.

[0083] The brown rice prepared in Example 4 has a hardness of 13.923 N, a viscosity of 0.612 N, a viscosity-hardness ratio of 0.044, and a chewiness of 5.636 N as determined by a texture measurement. Compared with the brown rice in Comparative Example 1, it can be seen that the hardness and chewiness are significantly reduced, and the viscosity and viscosity-hardness ratio are significantly increased, but the degree of improvement is still less than that of Example 2. Moreover, compared with the white rice, the viscosity and viscosity-hardness ratio differ too much. The texture parameters of the white rice are as follows: hardness of 13.232 N, viscosity of 1.901 N, viscosity-hardness ratio of 0.144, and chewiness of 5.657 N.

[0084] Example 5

[0085] A method for preparing a pre-prepared brown rice, comprising the following steps:

[0086] (1) After removing abnormal rice grains and impurities, the brown rice is directly soaked in room temperature water for 30 min without pre-fat removal treatment, and the mass-volume ratio of the brown rice to water is 1 g: 1.5 mL;

[0087] (2) Then, the water-soaked brown rice is ultrasonically treated at a frequency of 20 KHz, a power of 100 W, and a set temperature of 25°C for 30 min;

[0088] (3) The ultrasonically treated brown rice is directly heated in a water bath at 80°C for 30 min without adding any chemical reagent;

[0089] (4) The treated brown rice is washed with clean water for 3 times, drained, and then dried at 30°C for 7 h until the water content approaches the original water content of the brown rice.

[0090] In the above steps, steps (1), (2), and (4) are performed first, and then the dried brown rice is soaked in water again with a mass-volume ratio of 1 g: 1.5 mL, and the order and method described in (2), (3), and (4) are repeated once to prepare the pre-prepared brown rice.

[0091] The pre-prepared brown rice is heated and cooked in a sealed condition for 20 min with a rice-water ratio of 1 g: 1.0 mL, and then kept for 20 min to prepare brown rice.

[0092] The brown rice prepared in Example 5 has a hardness of 13.038 N, a viscosity of 0.482 N, a viscosity-hardness ratio of 0.037, and a chewiness of 4.604 N as determined by a texture measurement. Compared with the brown rice in Comparative Example 1, it can be seen that the hardness and chewiness are significantly reduced, and the viscosity and viscosity-hardness ratio are significantly increased, but the degree of improvement is far less than that of Example 2 and Example 4. Moreover, compared with the white rice, the viscosity and viscosity-hardness ratio differ too much. The texture parameters of the white rice are as follows: hardness of 13.232 N, viscosity of 1.901 N, viscosity-hardness ratio of 0.144, and chewiness of 5.657 N.

[0093] Example 6

[0094] A preparation method of pre-prepared brown rice, comprising the following steps:

[0095] (1) After removing abnormal rice grains and impurities, the brown rice is directly soaked in room temperature water for 30 min without pre-fat removal treatment, and the mass-volume ratio of the brown rice to water is 1 g: 1.5 mL;

[0096] (2) Then, the water-soaked brown rice is subjected to ultrasonic treatment for 30 min at a frequency of 20 KHz, a power of 100 W and a set temperature of 25℃;

[0097] (3) The ultrasonic-treated brown rice is directly subjected to water bath heating treatment at 80℃ for 30 min without adding any chemical reagent;

[0098] (4) The brown rice after the water bath heating treatment is washed with clean water for 3 times, drained and then dried at 30℃ for 7 h until the water content is close to the original water content of the brown rice.

[0099] (5) Then, the dried brown rice is again soaked in water, and the mass-volume ratio of the brown rice to water is 1:1.5, and the brown rice is subjected to the treatment again according to the sequence and method described in (2), (3) and (4) to obtain pre-prepared brown rice.

[0100] The pre-prepared brown rice is heated and cooked in water at a rice-water ratio of 1 g: 1.0 mL under airtight condition for 20 min and kept for 20 min to obtain brown rice.

[0101] The brown rice prepared in Example 6 is subjected to texture determination, and the hardness is 11.287 N, the viscosity is 1.114 N, the viscosity-hardness ratio is 0.099, and the chewiness is 4.329 N. Compared with the brown rice in Comparative Example 1, the hardness and chewiness of the brown rice prepared in Example 6 are significantly reduced, the viscosity and viscosity-hardness ratio are significantly increased, the improvement degree is better than that of other examples, and the viscosity and viscosity-hardness ratio are closest to those of the polished rice, and the quality is significantly improved. The texture parameters of the polished rice are as follows: hardness is 13.232 N, viscosity is 1.901 N, viscosity-hardness ratio is 0.144, and chewiness is 5.657 N.

[0102] Comparative Example 4

[0103] Other than Example 6, the set temperature of the ultrasonic treatment in step (2) is changed to 50℃.

[0104] The pre-prepared brown rice is heated and cooked in water at a rice-water ratio of 1:1.0 under airtight condition for 20 min and kept for 20 min to obtain brown rice.

[0105] The hardness of the brown rice prepared in Comparative Example 4 is 15.262 N, the viscosity is 0.724 N, the ratio of viscosity to hardness is 0.047, and the chewiness is 5.696 N. It can be seen that the hardness and chewiness are higher than those of Example 6, and the hardness is much higher than that of the fine white rice, while the viscosity and the ratio of viscosity to hardness are much lower than those of Example 6, and the quality of the brown rice is not good in general.

[0106] Comparative Example 5

[0107] Other than Example 6, the step (3) is directly heated in a water bath at 60°C for 30 min.

[0108] The above prepared brown rice is heated and cooked in a sealed condition with water at a ratio of 1:1.0 for 20 min, and then kept for 20 min to prepare brown rice.

[0109] The hardness of the brown rice prepared in Comparative Example 5 is 15.917 N, the viscosity is 0.351 N, the ratio of viscosity to hardness is 0.022, and the chewiness is 6.906 N. It can be seen that the hardness and chewiness are higher than those of Example 6, and are higher than those of the fine white rice, and the rice is hard and difficult to chew, while the viscosity and the ratio of viscosity to hardness are much lower than those of Example 6, and the quality of the brown rice is not good in general.

[0110] In summary, the pre-prepared brown rice prepared by the method of ultrasonic combined with hydrothermal treatment has moderate hardness, high viscosity, good chewiness, and the quality is obviously improved, which can improve the acceptance of consumers, and is expected to promote the popularization of brown rice as a main food.

[0111] The above detailed description of the method of preparing pre-prepared brown rice by ultrasonic combined with hydrothermal treatment in the reference examples is illustrative rather than limiting, and several examples can be listed within the limited range, and therefore the changes and modifications without departing from the overall concept of the present application shall fall within the protection scope of the present application.

Claims

1. A method for preparing pre-processed brown rice by ultrasonic combined with water bath heating treatment, characterized in that, The method includes the following steps: (1) Clean and remove impurities from brown rice, then soak it; (2) Soaked brown rice is subjected to ultrasonic treatment; (3) The brown rice processed in the previous step is subjected to water bath heating treatment; (4) Take out the brown rice processed in the previous step, wash it with water, drain it, and then dry it; (5) Next, the dried brown rice is soaked in water again, and the process is repeated once more in the order and method of (2), (3) and (4) above to obtain pre-processed brown rice; In step (2), the ultrasonic treatment is performed for 30 minutes at a frequency of 20 KHz, a power of 100 W, and a set temperature of 25℃. In step (3), no chemical reagents need to be added; the water bath is heated at 80°C for 30 min directly.

2. The method for preparing pre-processed brown rice by ultrasonic combined with water bath heating treatment according to claim 1, characterized in that, In step (1), after removing abnormal rice grains and impurities, brown rice does not need to be degreased beforehand; it can be soaked directly in room temperature water for 15-60 minutes.

3. The method for preparing pre-processed brown rice by ultrasonic combined with water bath heating treatment according to claim 1, characterized in that, In step (4), the treated brown rice is washed three times with clean water, drained, and then dried. The drying temperature is 25-35℃ and the time is 5-10 hours until the original moisture content is reached.

4. Whole grain pre-processed brown rice prepared by the method of preparing pre-processed brown rice by ultrasonic combined water bath heating treatment as described in any one of claims 1-3.