A method for enriching gaba in brown rice and brown rice gaba enrichment based on multi-cycle wet heat treatment

Abstract

The application provides a kind of GABA-rich brown rice and a kind of GABA-rich brown rice method based on multi-cycle wet heat treatment, which comprises the following steps: placing paddy in a enrichment device, achieving a certain moisture content of paddy by atomizing humidification mode, then carrying out high-temperature and low-temperature alternating cycle treatment on paddy, and carrying out high-temperature treatment once after the last low-temperature treatment, to complete the enrichment of GABA, GABA is continuously generated and migrates to the inside of the grain at the same time, and then drying treatment is carried out after the enrichment is completed. The application enriches GABA in paddy by multi-cycle wet heat treatment technology, and after enrichment by low-temperature stress combined with wet heat treatment, the content of GABA in brown rice and white rice obtained by milling the brown rice is greatly increased, the rate of burst waist is low, the sanitary quality is good, and the taste is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of methods for enriching functional components of grains, and specifically relates to a method for enriching brown rice rich in GABA and a method for enriching brown rice GABA based on multi-cycle moist heat treatment. Background Technology

[0002] Gamma-aminobutyric acid (GABA) is a non-protein amino acid. Long-term consumption of foods rich in GABA can effectively inhibit the rise in blood pressure in patients with hypertension and has a significant alleviating effect on menopausal syndrome and early-onset geriatric mental disorders. Its functionality and safety have been recognized. GABA can be used as a drug and a natural dietary supplement, and is now widely used in the medical and food fields as a health-promoting functional factor. However, the GABA content in brown rice is low (2-15 mg / 100g), far from sufficient to serve as an active ingredient in functional foods. Plant metabolism is a safe, effective, and simple method to increase its GABA content.

[0003] Currently, most enterprises still use the most traditional method—soaking and germination—to increase the GABA content in brown rice. This method is simple to operate and widely used. To further increase the GABA content, methods such as far-infrared irradiation (CN202111442978.X, GABA-germinated rice and its production process), low-oxygen stress (CN111838668A, a method for inhibiting β-glucan degradation and enriching GABA in barley germination), and ultrasonic stress (CN202210964983.5, a method for germinating high-γ-aminobutyric acid content germination rice) are being explored. Stress methods such as the preparation of glutinous rice, magnetic field stress (CN202310146667.1, a method for improving the γ-aminobutyric acid content of germinated brown rice through multi-factor combination), and low temperature stress (CN202310515478.7, a method for preparing germinated brown rice rich in GABA and GSH under low temperature stress) are often used in combination with soaking and germination methods. However, these methods require a long time (24-72 hours), and prolonged soaking leads to the loss of GABA and the proliferation of microorganisms, resulting in a high rate of brown rice cracking and a decline in nutritional and hygienic quality. In addition, patent CN205597054U discloses a device and method for enriching γ-aminobutyric acid in plant fruits. Although the water addition amount of this invention is lower than that of the soaking and germination method, it can improve the processing quality and eating quality of brown rice to a certain extent. However, its effect on increasing the GABA content in brown rice is limited, especially in promoting the migration of GABA into the grain and its effect on increasing the GABA content in white rice is poor. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for enriching GABA in brown rice based on multi-cycle moist heat treatment. By enriching rice with GABA through multi-cycle moist heat treatment technology, and after enrichment through low-temperature stress combined with moist heat treatment, the GABA content in brown rice and white rice obtained by milling the brown rice increases significantly, the breakage rate is low, and the eating quality and hygiene quality are improved.

[0005] The present invention also provides a GABA-rich brown rice, wherein the GABA-rich brown rice is enriched with GABA using the aforementioned brown rice GABA enrichment method based on multi-cycle wet heat treatment.

[0006] The present invention also provides a GABA-rich white rice, which is prepared from the GABA-rich brown rice.

[0007] The technical solution of this invention is:

[0008] A method for enriching brown rice with GABA based on multi-cycle humid heat treatment includes the following steps: placing paddy rice in an enrichment device, using a misting humidification mode to bring the moisture content of the paddy rice to a certain level, subjecting the paddy rice to alternating high-temperature and low-temperature treatments, and performing a high-temperature treatment after the last low-temperature treatment to complete the enrichment of GABA. GABA is continuously generated and migrates into the grain along with the moisture. After the enrichment is completed, the paddy rice is dried.

[0009] In the above scheme, the moisture content of rice is increased to 18%–24% through atomization humidification. The purpose of humidifying the rice is to enhance the activity of glutamate decarboxylase, catalyzing the decarboxylation reaction of glutamate to produce GABA. If the moisture content is below 18%, glutamate decarboxylase cannot be fully activated, resulting in a low GABA content; if the moisture content is above 24%, the rate of cracking will increase, and the sanitary quality of the rice will deteriorate.

[0010] In the above scheme, the relative humidity of the high-temperature stage in the high-temperature and low-temperature cyclic treatment is 75%–95%, the temperature is 55–75℃, and the treatment time is 1–3 hours each time. Suitable temperature is a necessary condition for maintaining high activity of glutamate decarboxylase. Below 55℃, glutamate decarboxylase activity is low; above 75℃, glutamate decarboxylase activity decreases, both of which can lead to low GABA content.

[0011] In the above scheme, the temperature of the low-temperature phase in the high-temperature and low-temperature cyclic treatment is -20 to 5°C, and the treatment time for each phase is 0.5 to 3 hours. Under low-temperature stress, the intracellular pH decreases, and Ca... 2+The large-scale release of calmodulin increases the expression level and enhances GAD activity, which can promote the accumulation of GABA in brown rice and white rice. At the same time, repeated heating and cooling cause cell membrane damage, increasing the contact opportunities between the enzyme and the substrate, thus rapidly accumulating GABA content.

[0012] In the above scheme, the high-temperature and low-temperature cyclic treatment is repeated 1 to 4 times, with one high-temperature treatment and one low-temperature treatment constituting one cycle. A cycle greater than 4 times can cause the generated GABA to convert to succinic acid, which is detrimental to GABA accumulation.

[0013] In the above scheme, the GABA migration refers to using the water solubility and concentration gradient of GABA to diffuse the higher concentration of GABA in the germ of brown rice to the endosperm along with water, thereby increasing the GABA content in the white rice obtained after milling the brown rice.

[0014] In the above scheme, the drying process involves placing the enriched rice in an environment with a relative humidity of 10%–30% and a temperature of 35–55°C to dry the rice until the moisture content of the rice reaches 12%–14.5%. Low-temperature drying ensures that the nutrients in the rice are not lost, and that moisture diffuses more slowly from the inside out, resulting in better processability and nutritional quality of the rice.

[0015] A type of GABA-rich brown rice, wherein the GABA-rich brown rice is enriched using the aforementioned GABA enrichment method based on multi-cycle wet heat treatment.

[0016] A GABA-rich white rice, wherein the GABA-rich white rice is prepared from the GABA-rich brown rice.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. The present invention uses multiple cycles of low temperature stress combined with wet heat treatment to significantly increase the GABA content in brown rice. Furthermore, due to the migration of GABA, the GABA content in the endosperm is relatively high. Even if the refined white rice is made from this brown rice, it can ensure a sufficient daily intake of GABA, thus guaranteeing both taste and nutritional value.

[0019] 2. Compared with the soaking method, the present invention adopts a circulating wet heat treatment, which slows down the water absorption rate of rice during enrichment and the diffusion rate of moisture from the inside to the outside during drying, resulting in a lower rate of cracking of the enriched brown rice and improving its processing quality.

[0020] 3. Compared with the soaking method, the high temperature-low temperature cycle used in this invention makes the starch structure less stable and the starch more easily gelatinized. As a result, the hardness of enriched brown rice and white rice milled from the brown rice is lower and the stickiness is increased, which greatly improves the eating quality of the cooked rice.

[0021] 4. Compared with the soaking method, the present invention requires less water and a shorter enrichment time during the enrichment process, which can reduce the reproduction of microorganisms, reduce the generation of odors, and improve its hygienic quality. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto. Unless otherwise specified, the reagents, materials, etc. used in the following embodiments are all commercially available.

[0023] Example 1

[0024] A method for enriching brown rice with GABA based on multi-cycle humid heat treatment includes the following steps:

[0025] The rice was placed in an enrichment device, and the moisture content of the rice was increased to 20% through atomization humidification. Then, the rice was subjected to a high-temperature-low-temperature cycle treatment. The high-temperature treatment was carried out at 65°C and 75% relative humidity for 2 hours, and the low-temperature treatment was carried out at 5°C for 3 hours. Under these conditions, the high-temperature-low-temperature cycle was repeated twice, and a high-temperature treatment was carried out again after the last low-temperature treatment. After enrichment, the rice was dried at 10% relative humidity and 35°C. The moisture content of the dried rice was 12%.

[0026] The processing quality of brown rice under different enrichment methods is shown in Table 1. After treatment with the enrichment method of this invention, the GABA content in brown rice and white rice prepared by milling the brown rice increased from 42.90 mg / kg and 8.71 mg / kg to 242.36 mg / kg and 201.57 mg / kg, respectively. Furthermore, the GABA content in brown rice and white rice treated with multiple cycles of moist heat was 1.44 times and 1.91 times that of the traditional soaking and germination method, respectively. In white rice treated with soaking and germination, the GABA content accounted for 62% of the entire grain, while in white rice treated with multiple cycles of moist heat, the GABA content accounted for 83% of the entire grain. Therefore, the enrichment method of this invention can significantly increase the GABA content in brown rice and white rice, and facilitates the migration of GABA into the grain interior, thereby improving the nutritional value of brown rice and the white rice prepared from it.

[0027] Table 1. GABA content (mg / kg) in brown rice and white rice under different treatment methods

[0028]

[0029] Note: GABA content is on a dry basis; different capital letters in the same column indicate significant differences (p < 0.05).

[0030] Example 2

[0031] A method for enriching brown rice with GABA based on multi-cycle humid heat treatment includes the following steps:

[0032] The rice was placed in an enrichment device, and the moisture content of the rice was increased to 24% through atomization humidification. Then, the rice was subjected to a high-temperature-low-temperature cycle treatment. The high-temperature treatment was carried out at 75°C and 85% relative humidity for 1 hour, and the low-temperature treatment was carried out at -5°C for 2 hours. Under these conditions, the high-temperature-low-temperature cycle was repeated four times, and a high-temperature treatment was carried out again after the last low-temperature treatment. After enrichment, the rice was dried. During the drying process, the relative humidity was 30% and the temperature was 55°C. The moisture content of the dried rice was 14.5%.

[0033] Table 2 shows the cracking rate and total bacterial count of brown rice under different enrichment methods. Compared with soaking and germination, the cracking rate of brown rice treated with the enrichment device of this invention is lower. Compared with untreated raw brown rice, soaking and germination can significantly increase the total bacterial count in brown rice, but the total bacterial count in brown rice decreases significantly after four cycles of wet heat treatment. Therefore, in the enrichment method of this invention, lower water addition, shorter enrichment time, and higher enrichment temperature can give brown rice better processing quality and hygiene quality.

[0034] Table 2. Broken rice content and total bacterial count under different treatment methods.

[0035]

[0036] Note: Different letters in the same column indicate significant differences (p < 0.05).

[0037] Example 3

[0038] A method for enriching brown rice with GABA based on multi-cycle humid heat treatment includes the following steps:

[0039] The rice was placed in an enrichment device, and the moisture content of the rice was increased to 18% through atomization humidification. Then, the rice was subjected to a high-temperature-low-temperature cycle treatment. The high-temperature treatment was carried out at 55°C and 95% relative humidity for 3 hours, and the low-temperature treatment was carried out at -20°C for 0.5 hours. Under these conditions, the high-temperature-low-temperature cycle was repeated three times, and a high-temperature treatment was carried out again after the last low-temperature treatment. After enrichment, the rice was dried at 20% relative humidity and 45°C. The moisture content of the dried rice was 13%.

[0040] The processing quality of brown rice under different enrichment methods is shown in Table 3. Compared with soaking and germination, the cooked rice after enrichment treatment by the present invention has lower hardness and higher stickiness. Therefore, the enrichment method of the present invention can improve the edible quality of brown rice and the white rice obtained by milling.

[0041] Table 3 Texture properties of brown rice / white rice under different treatments

[0042]

[0043] Note: Different capital letters in the same column indicate significant differences between brown rice (p < 0.05), and different lowercase letters in the same column indicate significant differences between white rice (p < 0.05).

[0044] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0045] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for enriching brown rice with GABA based on multi-cycle hydrothermal treatment, characterized in that, Includes the following steps: The rice is placed in an enrichment device, and its moisture content is increased to 18%–24% using a misting humidification mode. The rice is then subjected to multiple alternating high-temperature and low-temperature treatments. Each alternating high-temperature and low-temperature treatment includes one high-temperature treatment, one low-temperature treatment, and a final high-temperature treatment after the last low-temperature treatment. During the high-temperature phase, the relative humidity is 75%–95%, the temperature is 55–75 °C, and each treatment lasts 1–3 hours. During the low-temperature phase, the temperature is -20–5 °C, and each treatment lasts 0.5–3 hours. The high-temperature and low-temperature treatment is repeated 1–4 times. The enrichment of GABA is completed. As GABA is continuously generated, it migrates into the interior of the grain along with the moisture. After enrichment, the grain is dried.

2. The method for enriching brown rice with GABA based on multi-cycle hydrothermal treatment according to claim 1, characterized in that, GABA migration refers to the process of using the water solubility and concentration gradient of GABA to diffuse the higher concentration of GABA in the germ of brown rice to the endosperm along with water.

3. The method for enriching brown rice with GABA based on multi-cycle hydrothermal treatment according to claim 1, characterized in that, The drying process involves placing the enriched rice in an environment with a relative humidity of 10% to 30% and a temperature of 35 to 55°C to dry the rice until the moisture content of the rice reaches 12% to 14.5%.

4. A type of brown rice rich in GABA, characterized in that, The GABA-rich brown rice is enriched with GABA using the GABA enrichment method based on multi-cycle wet heat treatment as described in any one of claims 1-3.

5. A type of white rice rich in GABA, characterized in that, The GABA-rich white rice is prepared using the GABA-rich brown rice described in claim 4.

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