Method for improving nutritional quality of germinated brown rice through ultrasonic-assisted salt induction

Abstract

The invention aims to provide a method for improving nutritional quality of germinated brown rice through ultrasonic-assisted salt induction. Brown rice is a whole-grain product and is rich in nutritional ingredients such as starch, protein, dietary fibers, vitamins and mineral substances and active functional factors. The nutritional ingredients of the germinated brown rice change drastically, and the nutritional value of the brown rice is greatly improved. According to the method, brown rice is taken as a raw material, the brown rice is soaked in a CaCl2 salt solution under the assistance of ultrasound, the germination temperature and time are optimized, the concentration of the CaCl2 salt solution is taken as an influence factor, and the change rule of nutritional ingredients and functional factors of the brown rice in the germination process is researched. Results show that after ultrasonic-assisted salt induction treatment, the contents of vitamin B2 and vitamin B6 in the germinated brown rice are increased to 58.2 mu g / 100g and 0.438 mg / 100g, and the content of gamma-aminobutyric acid is increased to 42.6 mg / 100g (dry basis). The germination of the brown rice promotes the activation and release of hydrolases such as amylase, protease and phytase, and nutritional ingredients in the brown rice are migrated, degraded, accumulated and the like, so that the nutritional quality of the brown rice is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to a method for improving the nutritional quality of germinated brown rice through ultrasound-assisted salt induction. Background Art

[0002] Rice, a widely cultivated crop worldwide, is a staple food enjoyed by Asians. Due to its superior edible qualities, such as taste and color, it is highly favored by consumers, and refined white rice and its products remain a staple food. While refined white rice has a soft, glutinous texture and is easily digestible, the processing removes the bran and germ, which deprives it of its germination function and many nutrients beneficial to human health, such as vitamins, minerals, and dietary fiber.

[0003] Brown rice is the rice kernel that has been husked, leaving the inner cortex intact. Compared to polished white rice, brown rice retains nutrients from the bran, such as essential fatty acids, dietary fiber, vitamins, minerals, and active functional factors, resulting in a significantly higher nutritional value than polished rice. However, cooking brown rice directly is time-consuming and difficult to chew, making it less smooth and flavorful than white rice. Research has found that germination dramatically alters the nutritional composition of brown rice, significantly increasing its nutrient content and producing a large number of bioactive substances that can promote health and prevent disease. Germination also softens the bran layer, improving its rough texture. Germination also activates many enzymes within the rice, significantly increasing its nutritional value. Germinated brown rice is considered to have a higher nutritional value than ungerminated brown rice. To obtain high-quality brown rice with a high content of nutritionally active ingredients, abiotic stresses can be used to manipulate the germination process.

[0004] At present, the utilization of stress treatment to improve the nutritional quality of germinated brown rice has been reported, including pulsed strong light irradiation, complex enzyme treatment, microwave-assisted enzyme treatment and other methods, but these methods have the problems of complex procedures, long time consumption and high cost. In addition, low temperature stress can also improve the nutritional quality of germinated brown rice (CN 116548286A), but this method is time-consuming, and this method has a great impact on the nutritional quality of γ-aminobutyric acid (350ug / g) in germinated brown rice. -1) is not very significant. Ultrasonic treatment can also improve the nutritional quality of brown rice (CN 111700212A), but the ability of ultrasonic treatment alone to erode or destroy the cellulose layer on the surface of brown rice is limited, and the palatability, processability and digestibility of the obtained product need to be improved. There is also a method for treating germinated brown rice with extrusion puffing (CN 103652634A), but it causes great damage to the nutritional elements in the germinated brown rice that are beneficial to human health. In view of the deficiencies of the above-mentioned prior art, the present invention provides a method for improving the nutritional quality of germinated brown rice by ultrasound-assisted salt induction. First, ultrasound treatment is used to destroy the cell wall of brown rice, reduce the barrier of the cortex to water diffusion, and make it easier for water molecules to pass through the cell wall and enter the tissue. During the germination process, brown rice can absorb additional free water and stimulate it to produce more α-amylase, thereby accelerating the germination process. Thereafter, CaCl2 salt stress can stimulate the acidification of the cytoplasm of germinated brown rice, and CaCl2 in the cytoplasm 2+ The increased level of ultrasound accelerates the brown rice's absorption of oxygen, water, and other substances, increases the activity of relevant hydrolases within the brown rice, and promotes changes such as the migration, degradation, and accumulation of nutrients, thereby increasing the nutritional value of the germinated brown rice. Combining ultrasound with CaCl2 salt treatment not only improves the nutritional value of brown rice, but also shortens the germination time, saving production costs, and providing technical support for improving the nutritional quality of germinated brown rice. Summary of the Invention

[0005] The present invention addresses the deficiencies of the prior art by providing a method for improving the nutritional quality of germinated brown rice through ultrasound-assisted salt induction, thereby providing a method for improving the nutritional quality of germinated brown rice and enhancing its refinement. Combining ultrasound with CaCl₂ salt stress to treat brown rice germination improves the nutritional quality of the germinated brown rice while reducing the production cost of the brown rice germination process.

[0006] Technical solution: The present invention provides a method for improving the nutritional quality of germinated brown rice by ultrasound-assisted salt induction, which comprises the following steps:

[0007] (1) Brown rice was washed three times with distilled water, soaked in 0.5% sodium hypochlorite solution for 30 min, and then washed with sterile water until neutral;

[0008] (2) Ultrasonic treatment: The brown rice treated in step (1) was subjected to ultrasonic treatment with the following parameters: ultrasonic power of 500 W and treatment time of 30 min;

[0009] (3) CaCl2 treatment: The washed brown rice was soaked in a solution of 15-25 mmol / L CaCl2 solution at a ratio of 1:1.5 (weight of brown rice (g) / volume of CaCl2 solution (mL)). The treatment time was 12 h.

[0010] (4) Germination: The brown rice treated in step (3) was drained and placed in a constant temperature and humidity incubator for germination. The germination temperature was set at 25° C. and the humidity was (85% RH) for 36 h.

[0011] (5) Post-treatment: During the treatment in step (4), the brown rice germination conditions are kept stable by spraying a CaCl2 solution of corresponding concentration. After the germination is completed, the brown rice treated in step (4) is placed in a 45°C oven for 7 hours to obtain germinated brown rice.

[0012] A further preferred condition of the present invention is that in step (3), the CaCl2 salt treatment parameters are set to a concentration of 25 mmol / L and a treatment time of 12 h.

[0013] The present invention provides a method for improving the nutritional quality of germinating brown rice by ultrasound-assisted salt induction. Compared with the prior art, the beneficial effect is as follows: the ultrasound and CaCl2 salt treatment methods are combined for brown rice germination. After the brown rice is ultrasonically treated, its cell wall is damaged, and water molecules can more easily pass through the cell wall and enter the cell tissue, thereby promoting faster germination. At the same time, combined with CaCl2 salt stress, the acidification of the cytoplasm of the germinating brown rice can be stimulated, and the CaCl2 in the cytoplasm can be increased. 2+ The increase in the level of nutrient content accelerates the absorption of oxygen, water and other substances by the germinated brown rice, which is beneficial to the accumulation of bioactive substances in the brown rice and the activation of various hydrolases such as protease and amylase, ultimately improving the nutritional value of the germinated brown rice. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attachment Figure 1 Effects of ultrasound-assisted salt treatment on the nutritional composition of germinated brown rice;

[0015] Attachment Figure 2 Effects of ultrasound-assisted salt treatment on vitamin content of germinated brown rice;

[0016] Attachment Figure 3 Effects of ultrasound-assisted salt treatment on γ-aminobutyric acid in germinated brown rice. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below with reference to the embodiments.

[0018] The methods for determining fat, starch, vitamins, γ-aminobutyric acid, and mineral elements in germinated brown rice in the following examples are as follows:

[0019] (1) Determination of starch: The first enzymatic hydrolysis method according to GB 5009.9-2016 “National Food Safety Standard - Determination of Starch in Foods” was used.

[0020] (2) Protein determination: The first method of Kjeldahl nitrogen determination in GB 5009.5-2016 “National Food Safety Standard - Determination of Protein in Food” was used.

[0021] (3) Determination of fat: Acid hydrolysis was performed using the second method of GB 5009.6-2016 “National Food Safety Standard - Determination of Fat in Foods”.

[0022] (4) Determination of vitamin B2: GB 5009.85-2016 “National Food Safety Standard - Determination of Vitamin B2 in Foods” was used.

[0023] (5) Determination of vitamin B6 (pyridoxine): GB 5009.154-2016 “National Food Safety Standard - Determination of Vitamin B6 in Foods” was used.

[0024] (8) Determination of γ-aminobutyric acid: The γ-aminobutyric acid content in three types of brown rice was determined using NY / T 2890-2016 “High-performance liquid chromatography method for the determination of γ-aminobutyric acid in rice”.

[0025] (7) Determination of calcium, molybdenum, zinc, manganese, sodium, iron, strontium and potassium: GB 5009.268-2016 “National Food Safety Standard - Determination of Multiple Elements in Food”.

[0026] The technical solution of the present invention is further described below with reference to the embodiments.

[0027] Example 1:

[0028] (1) Brown rice was washed three times with distilled water, soaked in 0.5% sodium hypochlorite solution for 30 min, and then washed with sterile water until neutral;

[0029] (2) Ultrasonic treatment: The brown rice treated in step (1) was subjected to ultrasonic treatment with the following parameters: ultrasonic power of 500 W and treatment time of 30 min;

[0030] (3) CaCl2 treatment: The washed brown rice was soaked in a solution of 0 mmol / L CaCl2 solution at a ratio of 1:1.5 (weight of brown rice (g) / volume of CaCl2 solution (mL)). The treatment time was 12 h.

[0031] (4) Germination: The brown rice treated in step (3) was drained and placed in a constant temperature and humidity incubator for germination. The germination temperature was set at 25° C. and the humidity was (85% RH) for 36 h.

[0032] (5) Post-treatment: During the treatment in step (4), the brown rice germination conditions are kept stable by spraying a CaCl2 solution of corresponding concentration. After the germination is completed, the brown rice treated in step (4) is placed in a 45°C oven for 7 hours to obtain germinated brown rice.

[0033] Example 2:

[0034] (1) Brown rice was washed three times with distilled water, soaked in 0.5% sodium hypochlorite solution for 30 min, and then washed with sterile water until neutral;

[0035] (2) Ultrasonic treatment: The brown rice treated in step (1) was subjected to ultrasonic treatment with the following parameters: ultrasonic power of 500 W and treatment time of 30 min;

[0036] (3) CaCl2 treatment: The washed brown rice was soaked in a solution of 15 mmol / L CaCl2 solution at a ratio of 1:1.5 (weight of brown rice (g) / volume of CaCl2 solution (mL)). The treatment time was 12 h.

[0037] (4) Germination: The brown rice treated in step (3) was drained and placed in a constant temperature and humidity incubator for germination. The germination temperature was set at 25° C. and the humidity was (85% RH) for 36 h.

[0038] (5) Post-treatment: During the treatment in step (4), the brown rice germination conditions are kept stable by spraying a CaCl2 solution of corresponding concentration. After the germination is completed, the brown rice treated in step (4) is placed in a 45°C oven for 7 hours to obtain germinated brown rice.

[0039] Example 3:

[0040] (1) Brown rice was washed three times with distilled water, soaked in 0.5% sodium hypochlorite solution for 30 min, and then washed with sterile water until neutral;

[0041] (2) Ultrasonic treatment: The brown rice treated in step (1) was subjected to ultrasonic treatment with the following parameters: ultrasonic power of 500 W and treatment time of 30 min;

[0042] (3) CaCl2 treatment: The washed brown rice was soaked in a solution with a ratio of brown rice weight (g) to CaCl2 solution volume (mL) of 1:1.5, the concentration of CaCl2 solution was 25 mmol / L, and the treatment time was 12 h.

[0043] (4) Germination: The brown rice treated in step (3) was drained and placed in a constant temperature and humidity incubator for germination. The germination temperature was set at 25° C. and the humidity was (85% RH) for 36 h.

[0044] (5) Post-treatment: During the treatment in step (4), the brown rice germination conditions are kept stable by spraying a CaCl2 solution of corresponding concentration. After the germination is completed, the brown rice treated in step (4) is placed in a 45°C oven for 7 hours to obtain germinated brown rice.

[0045] Comparative Example 1:

[0046] Comparative Example 1 was carried out in the same manner as Example 1, except that no ultrasonic treatment was performed.

[0047] The mineral element analysis results of the germinated brown rice in Examples 1 to 3 and the comparative example are shown in Table 1.

[0048] Table 1

[0049]

[0050] By the attached Figure 1-3 As can be seen from Table 1, compared with Comparative Example 1, the content of vitamins, proteins, calcium, and γ-aminobutyric acid in the germinated brown rice increases with the increase of CaCl2 salt concentration, reaching the highest level in Example 3. The changes in starch and fat content show an opposite trend, reaching the lowest in Example 3, indicating that ultrasonic salt stress shows a relatively obvious activation effect on amylase and lipase during brown rice germination. It can be seen from this that the germinated brown rice treated with ultrasound and CaCl2 salt has a higher nutritional value than the untreated germinated brown rice and has a lower fat content, which is more likely to be welcomed by consumers, indicating that ultrasound-assisted CaCl2 salt-treated germinated brown rice has a certain market potential.

Claims

1. A method for improving the nutritional quality of germinated brown rice by ultrasound-assisted salt induction, providing a method for improving the nutritional quality of germinated brown rice, characterized in that: The following steps are involved: (1) Brown rice was washed three times with distilled water, soaked in 0.5% sodium hypochlorite solution for 30 min, and then washed with sterile water until neutral; (2) Ultrasonic treatment: The brown rice treated in step (1) was subjected to ultrasonic treatment with the following parameters: ultrasonic power of 500 W and treatment time of 30 min; (3) CaCl2 treatment: The washed brown rice was soaked in a solution of 15-25 mmol / L CaCl2 solution at a ratio of 1:1.5 (weight of brown rice (g) / volume of CaCl2 solution (mL)). The treatment time was 12 h. (4) Germination: The brown rice treated in step (3) was drained and placed in a constant temperature and humidity incubator for germination, the germination temperature was set to 25° C., the humidity was (85% RH), and the treatment time was 36 h; (5) Post-treatment: During the treatment in step (4), the germination conditions of the brown rice are kept stable by spraying a CaCl2 solution of corresponding concentration. After the germination is completed, the brown rice treated in step (4) is placed in an oven at 45° C. and dried for 7 h to obtain germinated brown rice.

2. The method according to claim 1, characterized in that: In the step (2), the ultrasonic treatment parameters are set to a power of 500 W and a treatment time of 30 min.

3. The method according to claim 1, characterized in that: In the step (3), the CaCl2 salt treatment parameters are set to a concentration of 25 mmol / L and a treatment time of 12 h.

4. The method according to claim 1, characterized in that: In the step (4), the brown rice germination treatment parameters are set as a temperature of 25° C., a humidity (85% RH), and a treatment time of 36 h.

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