阅读说明：本技术 一种双重胁迫萌发制备发芽糙米的方法 (Method for preparing germinated brown rice by double-stress germination ) 是由 王韧 张颖 陈正行 周星 王涛 冯伟 于 2019-07-26 设计创作，主要内容包括：本发明公开了一种双重胁迫萌发制备发芽糙米的方法,属于谷物加工领域。本发明包括以下步骤：(1)稻谷的预处理；(2)糙米的消毒；(3)糙米的浸泡,包括使用高浓度的复合金属离子溶液浸泡处理,并在浸泡后期进行低氧通气处理；(4)糙米的双重胁迫萌发,包括使用低浓度的复合金属离子溶液浸泡处理,以及在萌发后期进行通气处理；(5)干燥终止发芽,常温保藏。与传统的浸泡式发芽工艺相比,本发明缩短了发芽周期,提高了糙米的发芽率和发芽糙米中γ-氨基丁酸(GABA)的含量,制备出的高GABA含量的全谷物发芽糙米,可以作为主食直接食用或者作为原料进行食品加工,具有广阔的市场前景,是一种简单高效的发芽糙米制备方法。(The invention discloses a method for preparing germinated brown rice by double stress germination, and belongs to the field of grain processing. The invention comprises the following steps: (1) pretreating rice; (2) sterilizing the brown rice; (3) soaking the brown rice, including soaking treatment by using a high-concentration composite metal ion solution, and performing low-oxygen ventilation treatment at the later stage of soaking; (4) double stress germination of brown rice, which comprises soaking treatment by using low-concentration composite metal ion solution and ventilation treatment at the later germination stage; (5) drying to stop germination, and preserving at normal temperature. Compared with the traditional soaking type germination process, the method shortens the germination period, improves the germination rate of the brown rice and the content of gamma-aminobutyric acid (GABA) in the germinated brown rice, can be used as staple food to eat directly or used as a raw material to process food, has wide market prospect, and is a simple and efficient germinated brown rice preparation method.)

1. A method for preparing germinated brown rice by double stress germination is characterized in that the method adopts two-stage ventilation and composite metal ion treatment of brown rice; the two-stage ventilation is that ventilation treatment is respectively carried out at the late stage of brown rice soaking and the late stage of forced germination of the brown rice; the composite metal ion treatment adopts Ca-containing²⁺And Zn²⁺And (4) treating the solution compounded by the two metal ions.

2. The method as claimed in claim 1, wherein the rice is used as a raw material, comprising the steps of:

(1) pretreatment of paddy;

(2) soaking the brown rice;

(3) carrying out stress germination on the brown rice;

(4) after the germination is finished, drying to obtain the germinated brown rice;

wherein, two-stage ventilation and composite metal ion treatment are adopted in the steps (2) and (3).

3. The method according to claim 2, wherein the step (1) is to select rice seeds with strong germination capacity, and after hulling and impurity removal, to sterilize the brown rice before germination; the brown rice is sterilized before germination by placing the brown rice into a container, adding a sodium hypochlorite solution with the concentration of 0.5-1%, soaking for 20-40 min, washing, and draining water for later use, wherein the usage ratio of the brown rice to the sodium hypochlorite solution is 1: (1-2).

4. The method of claim 2, wherein the step (2) is performed by: placing the brown rice with the water drained in a container, adding a high-concentration composite metal ion soaking solution, and beginning to soak; when the soaking time reaches 7-10h, blowing fresh air into the soaking solution, and setting the ventilation quantity to be 0.1-1.0L/min; stopping aeration after 2-5 h.

5. The method of claim 4, wherein the high-concentration composite metal ion soaking solution contains 20-50 mmol/L Ca²⁺And 5 to 15mmol/L Zn²⁺(ii) a The ratio of the volume of the soaking solution to the mass of the brown rice is (4-5): (2-3).

6. The method of claim 2, wherein the operation method of step (3) is: placing the cleaned brown rice into a container, adding a low-concentration composite metal ion soaking solution, and placing the container into a water bath at 20-30 ℃ to start the stress germination of the brown rice; replacing the soaking solution every 10-15 h; and after 20-24 hours of germination, blowing fresh air into the soaking solution, setting the ventilation volume to be 1.0-2.0L/min, and stopping ventilation and germination after 6-10 hours of ventilation.

7. The method of claim 6, wherein the low concentration complex metal ion soaking solution contains 5 to 10mmol/L Ca²⁺And 2 to 5mmol/L Zn²⁺(ii) a The ratio of the addition amount of the soaking solution to the use amount of the brown rice is (1-2): 1.

8. the method of claim 2, wherein the operation method of step (4) is: and cleaning and draining the germinated brown rice, and drying in an oven at 45-55 ℃ for 4-6 h.

9. The germinated brown rice produced by the method according to any one of claims 1 to 8.

10. Use of the germinated brown rice according to claim 9 in staple food and for the preparation of rice products, dairy products, frozen foods, wines, beverages, health care, medical treatments.

Technical Field

The invention relates to a method for preparing germinated brown rice by double stress germination, and belongs to the field of grain processing.

Background

The germinated brown rice is a whole grain food obtained by germinating brown rice under certain conditions. Compared with polished rice, the germinated brown rice is rich in GABA and dietary fiber, and the GABA content is usually more than 5 times of that of polished rice. GABA is a non-protein functional amino acid, and has various physiological functions of tranquilizing nerves, resisting anxiety, improving memory and sleep.

The existing traditional soaking type germinated brown rice preparation technology generally has the problems of long germination period, low germination rate, poor GABA enrichment effect and the like, influences the eating and processing quality of the germinated brown rice and limits the food utilization and industrial development of the germinated brown rice. The stress germination is a method for improving germination by changing the environmental conditions of seed germination through physical and chemical means and increasing the activity of endogenous enzymes of seeds through the stress reaction of the seeds in the germination process of the seeds. Common stress germination modes mainly comprise modes of ventilation, high/low temperature treatment, hypoxia, repeated seed soaking, metal ion solution soaking and the like.

Aeration stress is a stress mode for promoting the growth of the sprouts by increasing the oxygen content of the soaking solution, the germination period can be shortened, but if the aeration treatment is carried out in the whole germination process of the brown rice, the sprouts can grow too fast, and the eating and processing quality of the germinated brown rice is affected. Some metal ions can be combined with endogenous enzymes in seeds to influence the activity of the endogenous enzymes, and Ca is shown by research²⁺、Zn²⁺The metal ions can activate glutamate decarboxylase (GAD) in brown rice, and promote GABA production. Further, Fe²⁺Can also improve the germination rate and oxidation resistance of brown rice. Therefore, different stress treatment modes can bring different influences on the brown rice germination. At present, most of stress germination modes adopt single stress germination, and the method adopting two or more stresses is less, so that the problems of long germination period, low germination rate, poor GABA enrichment effect and the like in the traditional soaking type germinated brown rice preparation process cannot be effectively solved.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for carrying out two-stage aeration treatment in the late stage of soaking and the late stage of germination respectively, and adopting composite metal ions (Ca) in the whole process of soaking and germination²⁺And Zn²⁺) Methods of double stress germination of treatments. The method can greatly improve the GABA content in the germinated brown rice, shorten the germination time and improve the germination rate.

The first object of the present invention is to provide a method for preparing germinated brown rice by double stress germination, which treats brown rice with two-stage aeration and complex metal ions.

In one embodiment of the invention, the two-stage aeration is two times of aeration treatment in the late stage of soaking and the late stage of germination.

In one embodiment of the present invention, the complex metal ion treatment is carried out by using a composition containing Ca²⁺And Zn²⁺And (4) treating the solution compounded by the two metal ions.

In one embodiment of the present invention, the method for producing the rice comprises the following steps:

(1) pretreatment of paddy;

(2) soaking the brown rice;

(3) carrying out stress germination on the brown rice;

(4) after the germination is finished, drying to obtain the germinated brown rice;

wherein, two-stage ventilation and composite metal ion treatment are adopted in the steps (2) and (3).

In one embodiment of the present invention, the operation method of step (1) is: selecting rice seeds with strong germination capacity, hulling and removing impurities, selecting plump seeds with embryos, and storing at 4 ℃ for later use.

In one embodiment of the invention, the step (1) further comprises the disinfection of the brown rice before germination, namely, the brown rice is placed in a container, sodium hypochlorite solution with the concentration of 0.5-1% (v/v) is added, the brown rice is soaked for 20-40 min, then the brown rice is washed for several times by deionized water, and water is drained for standby application; the dosage ratio (g: mL) of the brown rice and the sodium hypochlorite solution is 1: (1-2).

In one embodiment of the present invention, the operation method of step (2) is: placing the brown rice with drained water into a container with a certain volume, simultaneously placing a plurality of air pump heads at the bottom of the container, adding a high-concentration composite metal ion soaking solution, and beginning to soak; after the soaking time reaches 7-10h, turning on a switch of an air pump, and blowing fresh air into the soaking solution, wherein the ventilation volume is set to be 0.1-1.0L/min; and (5) after ventilating for 2-5h, closing the air pump, and continuing the soaking stage for 12 h.

In one embodiment of the present invention, the high concentration composite metal ion soaking solution in the step (2) contains 20 to 50mmol/L Ca²⁺And 5 to 15mmol/L Zn²⁺The ratio (mL: g) of the addition amount of the soaking solution to the dosage of the brown rice is (4-5): (2-3). The concentration of the metal ions adopted in the soaking process is high, and the purpose of soaking is to enable the brown rice seeds to absorb water for resuscitation.

In one embodiment of the present invention, the operation method of step (3) is: washing the soaked brown rice with deionized water for several times, and draining after washing; continuously placing the cleaned brown rice into a container, adding a low-concentration composite metal ion soaking solution, placing the container into a water bath at the temperature of 20-30 ℃ to start the stress germination of the brown rice, and replacing the soaking solution every 10-15 hours; and after 20-24 hours of germination, opening a switch of the air pump, blowing fresh air into the soak solution, setting the air flow to be 1.0-2.0L/min, ventilating for 6-10 hours, closing the air pump, stopping germination, and continuing for 30 hours in the germination stage.

In one embodiment of the present invention, the low concentration composite metal ion soaking solution in step (3) contains 5 to 10mmol/L Ca²⁺And 2 to 5mmol/L Zn²⁺The ratio (mL: g) of the volume of the soaking solution to the mass of the brown rice is (1-2): 1. in the germination process, the low-concentration metal ion solution is adopted for soaking to play a role in maintaining the stress environment of metal ions, and the high-concentration metal ions are adopted in the soaking process to accelerate the penetration into the brown rice.

In one embodiment of the present invention, the operation method of step (4) is: washing the germinated brown rice for several times by using deionized water, draining, spreading in a tray, and drying in an oven at the temperature of 45-55 ℃ for 4-6 hours; and (5) obtaining a finished product after drying, namely the germinated brown rice subjected to double stress germination.

The second object of the present invention is to provide a germinated brown rice prepared by the above method.

The third purpose of the invention is to provide the application of the germinated brown rice in the aspects of staple food, rice product preparation, dairy products, frozen food, wine brewing, beverage, health care and medical treatment.

The invention has the beneficial technical effects that:

the invention takes the paddy as the raw material, adopts two-stage aeration treatment at the late stage of soaking and the late stage of sprouting and carries out composite metal ion (Ca) in the whole process of soaking and sprouting²⁺And Zn²⁺) The double stress germination is carried out in a soaking treatment mode, so that the GABA content can be greatly increased, the germination period of the brown rice can be greatly shortened, and the germination rate of the brown rice is improved.

Compared with the traditional soaking germination mode, the two-stage ventilation treatment mode provided by the invention can provide low-concentration oxygen at the late stage of the brown rice soaking, is beneficial to the recovery of the brown rice at the early stage, improves the germination rate, and can provide sufficient oxygen content for the brown rice breathing at the late stage of germination, promotes the growth of buds, shortens the germination period. In addition, the germination temperature (20-30 ℃) of the brown rice is the proper temperature for microbial propagation, and when the brown rice is metabolized to a certain degree, a material basis is provided for the growth of the microorganisms. Once the oxygen content in the soaking solution is low, the facultative anaerobic microorganisms can perform fermentation to produce acid, so that the anaerobic fermentation of the microorganisms can be effectively inhibited by performing aeration treatment at the later germination stage, and the quality of the germinated brown rice is ensured.

In the present invention, the brown rice is treated with different concentrations of complex metal ions (Ca) during the soaking and germination stages²⁺And Zn²⁺) The soaking solution can accelerate the water absorption rate of the brown rice in the soaking stage, ensure the full water absorption of the brown rice grains and the rapid recovery of the enzyme activity, and maintain a certain amount of metal in the germination stageThe ion concentration improves the enzyme activity of GAD and promotes the generation of GABA. The stress action of the complex metal ions is to realize GABA enrichment by regulating the activity of GAD. In the brown rice soaking stage, Ca²⁺And Zn²⁺As water penetrates inside the seed to reach the germ, it binds to the protein domain of GAD, thereby enhancing the viability of GAD. Compared with single metal ion stress, the two metal ions adopted by the invention have obvious synergistic effect, and the coexistence of the two metal ions can increase the combination rate of the metal ions and the protein domain, thereby further enhancing the activity of GAD. Therefore, complex metal ions (Ca) are used throughout the soaking and germination²⁺And Zn²⁺) The enrichment effect of stress on GABA is the best.

According to the invention, through reasonable combination and optimization of two stress means of ventilation and composite metal ion treatment, a remarkable synergistic effect is achieved, the germination period of the brown rice can be effectively shortened, the germination rate is improved, and the GABA content in the germinated brown rice is greatly increased. By adopting the method provided by the invention, the germination time can be shortened by 6-8 h, namely the bud length (about 0.2 cm) of 30h of germination can reach the effect of 36-38 h of traditional soaking germination, the germination rate is increased by about 2%, and the GABA content in the germinated brown rice is increased by about 150% compared with the traditional soaking germinated brown rice.

Drawings

FIG. 1 is a flow chart of the process for preparing germinated brown rice by dual stress germination of two-stage aeration treatment and composite metal ion soaking treatment using rice as a raw material according to the present invention.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of better illustrating the invention and is not intended to limit the invention thereto.

1. Measurement of GABA content

The method adopts a high performance liquid pre-column derivatization method for determination. Grinding brown rice, sieving with 60 mesh sieve, and mixing the sieved part with the un-sieved part. Weighing 1.0g brown rice powder (accurate to 0.0001g) in 50mL centrifuge tube, adding 10mL trichloroacetic acid with volume fraction of 5%, ultrasonically extracting for 30min, shaking for 2min on vortex mixer, standing for 5min, and centrifuging at 5000r/min for 5 min. Transferring the supernatant to a 25mL volumetric flask, extracting the sample residue once with 10mL of 5% trichloroacetic acid solution, combining the two extracting solutions, diluting to 25mL, shaking up, and waiting for derivatization.

Performing derivatization reaction before performing liquid phase test, setting a pre-column derivatization program: accurately sucking 2.0 μ L of extractive solution, 31.0 μ L of buffer solution, 4.0 μ L of OPA derivative solution, and 4.0 μ L of ultrapure water, extracting for 20 times, and performing gradient elution.

The test conditions of the high performance liquid phase are as follows: the chromatographic column is C₁₈The column, mobile phase A was 0.04mol/L sodium acetate solution (pH7.2), mobile phase B was methanol, acetonitrile and water (v/v/v 2: 1), elution time was 38min, column temperature was 40 ℃, detection wavelength was 436nm, sample size was 10. mu.L, and flow rate was 1.0L/min.

2. Determination of brown rice germination rate

The brown rice germination rate is measured before drying, 25g of samples are randomly sampled and weighed, and the number of the germination particles and the number of all the particles are counted, wherein the germination rate is determined by the ratio of the germination number to the number of all the seeds, namely the germination rate is the number of the germination particles/the number of all the brown rice particles.

3. Determination of sprout length of germinated brown rice

And (3) randomly taking 50 germinated brown rice seeds, measuring the bud length of each seed by using a vernier caliper, and then calculating the average value as the bud length, wherein the numerical value is expressed in cm.