CN118440794A - Germinated brown rice brewing process and application thereof - Google Patents

Abstract

The invention belongs to the technical field of brewing, and particularly relates to a germinated brown rice brewing process and application thereof. The invention optimizes the brewing process of germinated brown rice, firstly, fully soaking brown rice in water, then carrying out germination treatment, fully and uniformly mixing germinated brown rice and food-grade silicon dioxide, then steaming, and finally fermenting by using sweet distiller's yeast. The process can effectively prevent the germinated brown rice from being burnt, prolong the steaming time, finally improve the fermentation efficiency and increase the content of gamma-aminobutyric acid in the sweet fermented glutinous rice stock solution.

Description

A germinated brown rice brewing process and its application

Technical Field

The invention belongs to the technical field of wine making, and in particular relates to a germinated brown rice wine making process and application thereof.

Background technique

Brown rice is the caryopsis of rice after the outer protective cortex of the rice husk has been removed, and the inner protective cortex (pericarp, seed coat, and nucellar layer) of the rice grain is intact. Compared with ordinary refined white rice, brown rice is richer in vitamins, minerals, and dietary fiber, and is considered a green and healthy food.

The brown rice is cultured at a certain temperature and humidity, and then dried when the brown rice germinates to a certain extent to obtain germinated brown rice. A large amount of enzymes such as amylase, protease, phytase, etc. contained in the germinated brown rice are activated and released, and are converted from a bound state to a free state. Due to this physiological activation process, the crude fiber shell of the germinated brown rice is softened and degraded by enzymolysis, part of the protein is decomposed into amino acids, and starch is converted into sugars. At the same time, a variety of ingredients that promote human health and prevent and treat diseases are also produced, such as γ-aminobutyric acid, which is a non-protein amino acid with multiple physiological effects such as brain health, blood pressure reduction, weight loss and skin aging prevention. In addition, the germinated brown rice also contains trace elements, vitamins, dietary fiber and anti-lipid oxidation substances.

my country has a long history of developing winemaking technology. Most of the wines available on the market are white wine made from sorghum, and there is also sweet wine made from glutinous rice. In recent years, brown rice has been favored and praised by people because it is rich in highly physiologically active gamma-aminobutyric acid (GABA), glutathione (GSH) and inositol.

Chinese patent application CN112322421A uses the principle of back extraction (the process of extractant transferring from organic to aqueous solution is called back extraction) to separate the sweet fermented glutinous rice stock solution rich in γ-aminobutyric acid and purple-red or purple-black natural pigments with a certain alcohol content through physical methods such as squeezing and filtering. However, its γ-aminobutyric acid recovery rate is low; Chinese patent application CN107760512A uses a mixture of germinated brown rice and glutinous rice as raw materials, and makes sweet fermented glutinous rice through soaking, germination, steaming, cooling, inoculation, jar nesting, and heat preservation and fermentation. It is found that when steaming rice for too long, the rice becomes sticky and sticky, resulting in incomplete fermentation, thereby affecting the yield of γ-aminobutyric acid. Therefore, further improvements are needed to increase the content of γ-aminobutyric acid in the sweet fermented glutinous rice stock solution.

Summary of the invention

In order to solve the above problems, the present invention provides a germinated brown rice wine making process, which comprises the following steps:

(1) germinating brown rice to obtain germinated brown rice;

(2) dispersing food grade silicon dioxide in water, then adding germinated brown rice, placing under agitation for 1-2 hours, stopping stirring and draining water using a cellulose membrane with a pore size of 0.1-0.5 micrometer to obtain a mixture of germinated brown rice and silicon dioxide;

(3) steaming the germinated brown rice mixture obtained in step (2) in a steamer for 50-55 min, and then cooling to room temperature to obtain a product;

(4) inoculating with 0.2-0.5% of the mass of the product of step (3) in sweet wine koji and 1-2% of the mass of the product of step (3) in activated yeast solution, and fermenting at 28-30° C. for 3-5 days to obtain a wine fermentation liquid;

(5) Using a cellulose membrane with a pore size of 0.1-0.5 μm, the wine fermentation liquid is filtered to obtain the wine stock liquid.

Further, the step of germinating the brown rice comprises soaking the brown rice in water at 25-35° C. for 12-24 hours, and then germinating the brown rice at 25-35° C. and 70-80% humidity for 15-20 hours.

Furthermore, in step (2), the amount of food-grade silicon dioxide added is 50% of the weight of the brown rice.

Furthermore, the D90 particle size of food grade silicon dioxide is 8-10 microns and the minimum particle size is greater than 1 micron.

Furthermore, in step (3), the steaming temperature is 100-110°C.

Furthermore, the activated yeast solution is prepared as follows: active dry yeast is selected, put into a 20wt% sucrose solution, and activated at 35-40°C for 30 minutes to obtain an activated yeast solution with a mass concentration of 3%.

Furthermore, the recovery rate of γ-aminobutyric acid in the brewing stock solution reaches more than 85%.

Furthermore, the germinated brown rice brewing process may also include a step of blending the brewing stock solution, such as blending it with brewed liquor.

The present invention also provides wine brewed from germinated brown rice produced by the process described herein.

Furthermore, the content of γ-aminobutyric acid in the wine is 166-170 μg/g.

Beneficial Effects of the Invention

In order to improve the content of gamma-aminobutyric acid in germinated brown rice brewing stock solution, the present invention optimizes the germinated brown rice brewing process, first, the brown rice is fully soaked in water, then germinated, and then the germinated brown rice is steamed, generally speaking, the fully soaked germinated brown rice only needs about 30 minutes to be steamed when steamed, if the steaming time is too long, the brown rice will be sticky, which is not conducive to late fermentation, as shown in the comparative example 1 of the present invention, when the conventional 30min steaming, the gamma-aminobutyric acid content in the obtained brewing stock solution is significantly lower, and the steaming time is increased, and the gamma-aminobutyric acid content can be improved only when silicon dioxide powder exists. Therefore, the present invention unexpectedly found that when steaming germinated brown rice, adding fully mixed food-grade silicon dioxide can effectively prevent the germinated brown rice from becoming sticky, extend the steaming time, and finally improve the fermentation efficiency, and increase the content of gamma-aminobutyric acid in sweet fermented glutinous rice stock solution.

Detailed ways

The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

In the following specific implementation manner, the sweet wine koji is Angel sweet wine koji, Angel Yeast Co., Ltd.; the active dry yeast is Angel Baijiu King high-activity dry yeast, Angel Yeast Co., Ltd.

Example 1

This embodiment provides a germinated brown rice wine brewing process, which comprises the following steps:

(1) soaking brown rice in water at 28° C. for 15 hours, and then germinating the rice at 28° C. and 80% humidity for 16 hours to obtain germinated brown rice;

(2) 50% of the brown rice mass of food-grade silicon dioxide (D90 particle size is 10 microns and the minimum particle size is greater than 1 micron) is dispersed in water 3 times the mass of the food-grade silicon dioxide, then the germinated brown rice is added, and the mixture is placed under agitation for 1 hour, and then the stirring is stopped and the water is drained using a 0.22 micron cellulose membrane to obtain a mixture of the germinated brown rice and silicon dioxide;

(3) steaming the germinated brown rice mixture obtained in step (2) in a steamer for 50 min, and then cooling to room temperature to obtain a product;

(4) inoculating the product of step (3) with 0.2% of sweet wine koji and 1% of activated yeast solution relative to the mass of the product of step (3), and fermenting at 30° C. for 5 days to obtain wine fermentation liquid, wherein the activated yeast solution is prepared as follows: selecting active dry yeast, placing it in a 20wt% sucrose solution, and activating it at 38° C. for 30 minutes to obtain an activated yeast solution with a mass concentration of 3%;

(5) The wine fermentation liquid is filtered using a 0.22 μm cellulose membrane to obtain the wine stock liquid.

Example 2

This embodiment provides a germinated brown rice wine brewing process, which comprises the following steps:

(1) soaking brown rice in water at 32° C. for 24 hours, and then germinating the rice at 32° C. and 70% humidity for 18 hours to obtain germinated brown rice;

(2) 50% brown rice mass of food-grade silicon dioxide (D90 particle diameter is 10 microns and minimum particle diameter is greater than 1 micron) is dispersed in water 3 times the mass of food-grade silicon dioxide, then germinated brown rice is added, and the mixture is placed under agitation for 2 hours, and then stirring is stopped and the water is drained using a 0.22 micron cellulose membrane to obtain a mixture of germinated brown rice and silicon dioxide;

(3) steaming the germinated brown rice mixture obtained in step (2) in a steamer for 55 min, and then cooling to room temperature to obtain a product;

(4) inoculating with 0.5% of the mass of the product of step (3) in sweet wine koji and 2% of the mass of the product of step (3), and fermenting at 28° C. for 3 days to obtain a wine fermentation liquid, wherein the activated yeast liquid is prepared as follows: selecting active dry yeast, placing it in a sucrose solution with a concentration of 20 wt%, activating it at 38° C. for 30 min, and obtaining an activated yeast liquid with a mass concentration of 3%;

(5) The wine fermentation liquid is filtered using a 0.22 μm cellulose membrane to obtain the wine stock liquid.

Comparative Example 1

This comparative example provides a germinated brown rice brewing process, which comprises the following steps:

(1) soaking brown rice in water at 28° C. for 15 hours, and then germinating the rice at 28° C. and 80% humidity for 16 hours to obtain germinated brown rice;

(2) steaming the germinated brown rice mixture obtained in step (1) in a steamer for 30 minutes, and then cooling to room temperature;

(4) inoculating with 0.2% of the mass of the product of step (3) in sweet wine koji and 1% of the mass of the product of step (3), and fermenting at 30° C. for 5 days to obtain a wine fermentation liquid, wherein the activated yeast liquid is prepared as follows: selecting active dry yeast, placing it in a sucrose solution with a concentration of 20wt%, activating it at 38° C. for 30 minutes, and obtaining an activated yeast liquid with a mass concentration of 3%;

(4) The wine fermentation liquid is filtered using a 0.22 μm cellulose membrane to obtain the wine raw liquid.

Comparative Example 2

This comparative example provides a germinated brown rice wine brewing process, which differs from comparative example 1 in that the steaming time in step (2) is 40 minutes, and the remaining steps are the same as those in example 1.

Comparative Example 3

This comparative example provides a germinated brown rice wine brewing process, which differs from Example 1 in that step (2) is omitted, and the remaining steps are the same as those in Example 1.

Comparative Example 4

This comparative example provides a germinated brown rice wine brewing process, which is different from Example 1 in that in step (3), the steaming time is 30 minutes, and the remaining steps are the same as those in Example 1.

Comparative Example 5

This comparative example provides a germinated brown rice wine brewing process, which differs from Example 1 in that in step (3), the steaming time is 40 minutes, and the remaining steps are the same as those in Example 1.

Comparative Example 6

This comparative example provides a germinated brown rice wine brewing process, which is different from Example 1 in that in step (3), the steaming time is 45 minutes, and the remaining steps are the same as those in Example 1.

Comparative Example 7

This comparative example provides a germinated brown rice wine brewing process, which is different from Example 1 in that in step (3), the steaming time is 60 minutes, and the remaining steps are the same as those in Example 1.

The contents of γ-aminobutyric acid in the germinated brown rice and brewing stock solutions prepared in Examples 1-2 and Comparative Examples 1-7 were respectively detected, and the results are shown in Table 1.

Among them, the content of γ-aminobutyric acid in germinated brown rice is determined as follows:

(1) Grinding: Take 5 g of germinated brown rice sample, add 8 ml of water, and grind on ice.

(2) Vortex for 1 min and perform ultrasonic extraction at 4 °C for 30 min.

(3) The homogenate was divided into 1.5 ml centrifuge tubes and centrifuged at 10,000 rpm and 4°C for 10 min.

(4) Discard the precipitate, take the supernatant, and combine the supernatants.

(5) Filter through a 0.45 μm filter membrane to prepare the sample to be tested and store at 4°C.

(6) Take 150 μl of the sample to be tested, add 50 μl of 0.1 mol/L sodium tetraborate and 100 μl of 6% redistilled phenol, and mix well.

(7) Add 150 μl of 7.5% NaCl O solution to the mixture and mix well.

(8) Place in a boiling water bath for 10 min, then immediately place in an ice bath for 5 min. The solution will turn blue-green.

(9) Add 500 μl of 60% ethanol and mix well.

(10) Measure the OD value at 645 nm and complete the measurement within 1 hour.

(11) Preparation of standard curve: Take 150 μl of 0.02, 0.05, 0.1, 0.15, 0.25, 0.3, 0.5, and 0.6 mg/ml γ-aminobutyric acid solutions and repeat steps (6) to (10).

(12) Calculate the content of γ-aminobutyric acid in germinated brown rice.

The above determination was performed on the germinated brown rice prepared in Example 1-2 and Comparative Example 1-7 in triplicate, and the average value was finally taken as the initial content of γ-aminobutyric acid in the germinated brown rice before brewing.

The content of γ-aminobutyric acid in the brewing liquid prepared in Example 1-2 and Comparative Example 1-7 is determined by the above steps (6) to (10).

Table 1: Content of γ-aminobutyric acid in germinated brown rice and brewing stock solution prepared in Examples 1-2 and Comparative Examples 1-7

From the results in Table 1, it can be seen that the content of γ-aminobutyric acid in the brewing stock solution prepared in Examples 1 and 2 of the present invention is significantly higher than that when the germinated brown rice is conventionally steamed without using food-grade silicon dioxide (Comparative Example 1), and the recovery rate is increased by about 20%, which indicates that the silicon dioxide added by the present invention can significantly improve the extraction rate of γ-aminobutyric acid with a specific process method. When the germinated brown rice is conventionally steamed and the steaming time is increased (Comparative Example 2), the content of γ-aminobutyric acid in the prepared brewing stock solution not only does not increase, but decreases, which indicates that the conventional steaming method increases the steaming time due to excessive gelatinization, which affects the extraction rate of γ-aminobutyric acid. When the process method of the present invention is used but food-grade silicon dioxide is not used (Comparative Example 3), the content of γ-aminobutyric acid in the prepared brewing stock solution is significantly lower than that in Examples 1 and 2 of the present invention, and is also lower than that in Comparative Example 1. This is because in the process of the present invention, the rice is steamed for up to 50 minutes under sufficient immersion. If food-grade silicon dioxide is not added, the brown rice will become more mushy during steaming, thereby affecting the subsequent fermentation, resulting in incomplete fermentation and reducing the extraction recovery rate of γ-aminobutyric acid. In Comparative Examples 4-7, the steaming time of step (5) in the process of the present invention was adjusted. It was found that from 30 min to 60 min, the content of γ-aminobutyric acid in the brewing stock solution first increased and then decreased. This indicates that with the increase of steaming time, the γ-aminobutyric acid in the germinated brown rice can be more fully extracted. At 50-55 min, the recovery rate of γ-aminobutyric acid reached the maximum. When the steaming time was further increased to 60 min, the recovery rate was reduced to below 85%. This may be because too long steaming time will still cause the germinated brown rice to become mushy, thereby affecting the fermentation effect and reducing the γ-aminobutyric acid content.

It should be noted that the preferred embodiments of the present invention are given in the specification of the present invention, but the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not intended to be additional limitations on the content of the present invention. The purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. In addition, the above-mentioned technical features continue to be combined with each other to form various embodiments not listed above, which are all considered to be within the scope of the present invention specification; further, for ordinary technicians in this field, they can be improved or transformed according to the above description, and all these improvements and transformations should belong to the protection scope of the claims attached to the present invention.

Claims (9)

1. A germinated brown rice brewing process, characterized in that it comprises the following steps: (1) germinating brown rice to obtain germinated brown rice; (2) dispersing food grade silicon dioxide in water, then adding germinated brown rice, placing under agitation for 1-2 hours, stopping stirring and draining water using a cellulose membrane with a pore size of 0.1-0.5 micrometer to obtain a mixture of germinated brown rice and silicon dioxide; (3) steaming the germinated brown rice mixture obtained in step (2) in a steamer for 50-55 min, and then cooling to room temperature to obtain a product; (4) inoculating with 0.2-0.5% of the mass of the product of step (3) in sweet wine koji and 1-2% of the mass of the product of step (3) in activated yeast solution, and fermenting at 28-30° C. for 3-5 days to obtain a wine fermentation liquid; (5) Using a cellulose membrane with a pore size of 0.1-0.5 μm, the wine fermentation liquid is filtered to obtain the wine stock liquid. 2. The germinated brown rice brewing process according to claim 1, wherein the brown rice is germinated by soaking the brown rice in water at 25-35° C. for 12-24 hours, and then germinating the brown rice at 25-35° C. and 70-80% humidity for 15-20 hours. 3. The germinated brown rice brewing process according to claim 1, characterized in that, in step (2), the addition of food grade silicon dioxide is 50% of the brown rice quality. 4. germinated brown rice brewing process according to claim 1, is characterized in that the D90 particle size of food grade silicon dioxide is 8-10 micron and the minimum particle size is higher than 1 micron. 5. The germinated brown rice wine making process according to claim 1, characterized in that, in step (3), the steaming temperature is 100-110°C. 6. The germinated brown rice brewing process according to claim 1 is characterized in that the activated yeast solution is prepared as follows: active dry yeast is selected, placed in a sucrose solution with a concentration of 20wt%, and activated at 35-40°C for 30min to obtain an activated yeast solution with a mass concentration of 3%. 7. The germinated brown rice brewing process according to claim 1, characterized in that the recovery rate of γ-aminobutyric acid in the brewing stock solution reaches more than 85%. 8. Wine brewed from germinated brown rice, characterized in that it is produced by the process described in any one of claims 1 to 7. 9. The wine according to claim 8, characterized in that the content of γ-aminobutyric acid in the wine is 166-170 μg/g.