Processing method for increasing GABA (gamma-aminobutyric acid) content of cooked highland barley powder

Abstract

The invention relates to the technical field of food processing, in particular to a processing method for increasing GABA (gamma-aminobutyric acid) content of cooked highland barley flour, which comprises the following steps: step 1, cleaning: weighing highland barley grains and cleaning; step 2, soaking: soaking the highland barley grains with water; step 3, sprouting: placing the highland barley grains under low-oxygen and low-pressure conditions for sprouting; step 4, pulping: grinding the germinated highland barley grains, and keeping the temperature at 40-55 DEG C for 45-60 minutes to obtain highland barley pulp; and step 5, curing and drying: curing and drying the highland barley slurry to obtain the cooked highland barley powder rich in GABA. The problems that the GAD activity is reduced, the content of GABA in highland barley cannot be effectively increased, the energy consumption is high and the production cost is high can be solved under the condition of not adding an exogenous reagent and an enzyme preparation.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to a processing method for increasing the GABA content of cooked highland barley flour. Background Art

[0002] GABA (γ-aminobutyric acid) is a natural non-protein amino acid, which is synthesized by the irreversible α-decarboxylation reaction of L-Glu (L-glutamic acid) or its salt catalyzed by GAD (gluta mate decarboxylase) and its cofactor PLP (pyridoxalphosphate).

[0003]

[0004] Highland barley is a cereal crop of the genus Hordeum. GABA in highland barley is one of the more special substances contained in highland barley. GABA is an important inhibitory neurotransmitter in the central nervous system of mammals, which can effectively reduce the nerve excitability of the central nervous system of mammals. Intake of a certain amount of GABA has physiological effects such as improving the body's sleep quality and lowering blood pressure.

[0005] At present, the content of GABA in highland barley is usually increased by external stimulation of highland barley during the germination stage. For example, the patent with publication number CN111838668B discloses a highland barley germination method for inhibiting the degradation of β-glucan and enriching GABA, wherein highland barley is germinated in a 15°C constant temperature and humidity incubator for 24 hours; then deionized water is sprayed at intervals, and after draining, it is placed in a packaging bag and vacuumed with a small vacuum sealer, and then the vacuum degree is 0.07MPa. It is stored in a 15°C constant temperature and humidity incubator for 24 hours. Then, the enzyme is inactivated in an oven for 10 minutes (90°C), and the product is spread on a tray at 40°C for hot air drying for 12 hours, taken out, crushed, and sieved through a 50-mesh sieve to obtain germinated highland barley powder. Although this method can increase the content of GABA in highland barley, the germinated highland barley is directly deactivated in an oven, causing the GAD in the germinated highland barley to lose activity quickly, and it is impossible to produce GABA by enzymolysis, and then it is impossible to increase the content of GABA. Even if the deactivation operation is not performed, the activity of GAD in the germinated highland barley will gradually decrease over time, and it is impossible to effectively increase the content of GABA in highland barley. And the prior art needs to use special equipment to maintain the stress environment such as hypoxia and low pressure, and the energy consumption is high, which greatly increases the production cost. Summary of the invention

[0006] The invention provides a processing method for increasing the GABA content of cooked highland barley flour, which can solve the problems of reduced GAD activity, inability to effectively increase the GABA content in highland barley, high energy consumption and high production cost without adding exogenous reagents and enzyme preparations.

[0007] This application provides the following technical solutions:

[0008] A processing method for increasing the GABA content of cooked highland barley flour, characterized in that it comprises the following steps:

[0009] Step 1: Cleaning: Weigh highland barley grains and clean them.

[0010] Step 2: Soak: Soak the highland barley seeds in water.

[0011] Step 3: Germination: Place the highland barley grains under low oxygen and low pressure conditions for germination.

[0012] Step 4, pulping: grinding the germinated highland barley grains, keeping warm at 40-55° C. for 45-60 minutes, and obtaining highland barley slurry.

[0013] Step 5, aging and drying: the highland barley slurry is aged and dried to obtain cooked highland barley powder rich in GABA.

[0014] Beneficial effects: Germinating highland barley grains under low oxygen and low pressure conditions can effectively activate GAD in highland barley and promote the accumulation of GABA. Grinding the germinated highland barley grains not only improves the uniformity and fineness of the material, but also increases the damage rate of the cell wall, making it easier to release nutrients such as GABA. The damage to the cell wall also increases the contact area between GAD and glutamate, thereby promoting the synthesis of GABA. The ground highland barley is kept warm at 40-55°C for 45-60 minutes, which provides the optimal reaction temperature for GAD, increases the activity of GAD, further promotes the synthesis of GABA, and effectively increases the content of GABA in highland barley. At the same time, this technical solution is easy to industrialize, ensures the consistency and stability of product quality, and does not require complex equipment, reduces production costs, and improves economic benefits.

[0015] Preferably, the weight ratio of highland barley grains to water during the soaking process in step 2 is 1:4-6.

[0016] This ratio ensures that the barley grains can fully absorb water and swell, activating the internal enzyme system and thus promoting the production of GABA.

[0017] Preferably, during the soaking process in step 2, the soaking temperature is 18-23° C., the soaking time is 2-6 hours, and air is introduced during the soaking process.

[0018] Soaking highland barley seeds at 18-23℃ for 2-6 hours can effectively improve their germination rate, thereby increasing the GABA content in highland barley.

[0019] Preferably, during the germination process of step 3, the highland barley grains are placed under low oxygen and low pressure conditions with an oxygen content of 15-16% and an atmospheric pressure of 60-70 KPa for germination.

[0020] Germinating highland barley grains in an environment with an oxygen content of 15-16% and an atmospheric pressure of 60-70KPa can effectively increase the GABA content. Moreover, this environment can be achieved by utilizing Tibet's unique natural environment. There is no need to use equipment to create low-oxygen and low-pressure conditions. It is simple to operate and can effectively reduce production costs.

[0021] Preferably, during the germination process in step 3, the germination cultivation temperature is 18-23° C., and the germination cultivation time is 24-48 hours.

[0022] During the germination of highland barley grains, the GABA content in highland barley generally showed a trend of increasing first and then decreasing. Under the temperature conditions of 18-23°C, GABA accumulated slowly within 24 hours of germination cultivation, accumulated fastest within 24-48 hours of germination cultivation, and the GABA content decreased after 48 hours of germination cultivation. Therefore, the GABA content in highland barley was the highest when the germination cultivation time was 24-48 hours.

[0023] Preferably, the grinding in step 4 is performed by a colloid mill, water is added during the colloid milling process, and the colloid milling is performed at least twice.

[0024] When the germinated highland barley grains pass through the colloid mill, they absorb the heat emitted by the colloid mill equipment when it is working. Therefore, the temperature of the material itself can reach 40-50°C after passing through the colloid mill, that is, it can reach the required temperature for insulation without additional heating, effectively reducing energy consumption, simplifying process steps, and reducing costs. At least 2 colloid mills can ensure the uniformity and fineness of the material, ensure that the material can fully absorb heat to reach the required insulation temperature, and ensure the taste of the final product.

[0025] Preferably, the aging and drying in step 5 is carried out by adiabatic steam drying, the steam pressure is 0.45-0.65 MPa, the steam temperature is 110-130° C., and the steaming time is 4-6 min.

[0026] Using adiabatic steam drying technology, during the drying process, the surface moisture of the material is evaporated first, and then the internal moisture gradually migrates to the surface and evaporates. The above drying conditions can not only ensure fast and efficient removal of moisture, but also retain the nutrients in highland barley, while enhancing the flavor of the product, and the drying speed is fast, efficient and easy to operate. DETAILED DESCRIPTION

[0027] The following is further described in detail through specific implementation methods:

[0028] A processing method for increasing the GABA content of cooked highland barley flour comprises the following steps:

[0029] Step 1, cleaning: weigh highland barley grains, and use a cleaning machine to clean them 3-5 times to remove impurities on the surface of the highland barley grains.

[0030] Step 2, soaking: put the highland barley grains cleaned in step 1 into a soaking device, soak the highland barley grains with water, the weight ratio of highland barley grains to water is 1:4-6, the soaking temperature is 18-23° C., the soaking time is 2-6 hours, and air is introduced during the soaking process. At least two ventilation pipes are provided on the soaking device, and air is introduced into the feed liquid during the soaking of highland barley grains. The air introduction frequency is 20-60 times / min, and the air introduction amount of each ventilation pipe is 300-500 milliliters each time, and air exchange is continuously maintained to prevent deterioration during the soaking process.

[0031] Step 3, germination: placing the highland barley grains soaked in step 2 under low oxygen and low pressure conditions with an oxygen content of 15-16% and an atmospheric pressure of 60-70 KPa for germination, the germination cultivation temperature is 18-23° C., the germination cultivation time is 36-48 hours, and the germinated highland barley grains are obtained. The low oxygen and low pressure conditions can adopt the unique natural environment of Tibet.

[0032] Step 4, pulping: grinding the germinated highland barley grains in step 3, keeping warm at 40-55° C. for 45-60 minutes, and obtaining highland barley slurry. The grinding adopts a colloid mill, water is added during the colloid mill, the mass ratio of the germinated highland barley grains to water is about 2:1, and the colloid mill is performed at least twice, so that the fineness of the highland barley slurry meets the requirements, the moisture content in the highland barley grains after the colloid mill is about 50-55%, and the temperature of the highland barley grains after the colloid mill can reach 40-50° C. The material after the colloid mill is placed in a storage tank for insulation storage for 45-60 minutes to obtain highland barley slurry.

[0033] Step 5, aging and drying: The highland barley slurry obtained in step 4 is subjected to adiabatic steam steaming and drying, the steam pressure is 0.45-0.65 MPa, the steam temperature is 110-130° C., the steaming time is 4-6 min, and after steaming, it is crushed to obtain GABA-rich highland barley flour, the particle size range of the highland barley flour is 60-80 mesh.

[0034] Example 1

[0035] A processing method for increasing the GABA content of cooked highland barley flour, the specific steps are as follows:

[0036] Step 1, cleaning: weigh 30 kg of highland barley grains, and clean them three times with a cleaning machine to remove impurities on the surface of the highland barley grains.

[0037] Step 2, soaking: put the highland barley grains cleaned in step 1 into a soaking device, soak the highland barley grains with water, the weight ratio of highland barley grains to water is 1:5, the soaking temperature is 20°C, and the soaking time is 4h.

[0038] Step 3, germination: the highland barley grains soaked in step 2 are placed under low oxygen and low pressure conditions with an oxygen content of 15.09% and an atmospheric pressure of 65.23 KPa for germination, the germination cultivation temperature is 20° C., the germination cultivation time is 48 hours, and the germinated highland barley grains are obtained. The low oxygen and low pressure conditions adopt the unique natural environment of Tibet.

[0039] Step 4, pulping: grinding the highland barley grains germinated in step 3 by a colloid mill, adding water during the colloid milling process, the mass ratio of the germinated highland barley grains to water is about 2:1, and the colloid milling is performed at least twice, so that the fineness of the highland barley slurry meets the requirements, the moisture content in the highland barley grains after the colloid mill is about 50%, the temperature of the highland barley grains after the colloid mill can reach 45° C. The highland barley slurry after the colloid mill is placed in a storage tank for heat preservation and storage for 60 minutes to obtain highland barley slurry.

[0040] Step 5, aging and drying: The highland barley slurry obtained in step 4 is subjected to adiabatic steam steaming and drying, the steam pressure is 0.65 MPa, the steam temperature is 110-130° C., the steaming time is 4-6 min, and after steaming, it is crushed to obtain GABA-rich highland barley flour, the particle size range of which is 60-80 mesh.

[0041] Experiment 1

[0042] Weigh the same weight of highland barley grains for soaking. Under the same other conditions, the soaking time is different and the germination rate of the highland barley grains is different, as shown in Table 1 below.

[0043] Table 1. Effect of soaking time on germination rate

[0044]

[0045]

[0046] As shown in Table 1, under the same other conditions, the germination rate of highland barley grains is above 92% when soaked for 2 to 6 hours and germinated for 48 hours. Among them, the germination rate of highland barley grains is the highest, reaching 96.60%, when soaked for 4 hours and germinated for 48 hours.

[0047] Experiment 2

[0048] Weigh the same weight of highland barley seeds, soak them for 4 hours, and then perform germination cultivation. Under the same other conditions, the germination time is different and the GABA content in the highland barley is different, as shown in the following table.

[0049] Table 2. Effect of germination time on GABA content

[0050]

[0051] As shown in Table 2, during the entire germination process, the GABA content in highland barley generally showed a trend of increasing first and then decreasing. GABA accumulated slowly in the early germination period (0-24h), accumulated fastest in the middle germination period (24-48h), and decreased in the late germination period (48-72h). This is because the protease was not fully activated in the early germination period of highland barley grains. As the germination time increased, protein hydrolysis formed glutamate, which was converted into GABA under the action of GAD. The generation and consumption of GABA is a dynamic equilibrium process. As GABA accumulates, the activity of GAD is inhibited and the activity of GABA transaminase is promoted, so that GABA is converted into succinic semialdehyde, resulting in a decrease in GABA content. It can be seen that the GABA content in highland barley is the highest when the soaking time of highland barley grains is 4h and the germination time is 48h.

[0052] Experiment 3

[0053] Using the processing method of Example 1, the same weight of highland barley seeds were weighed, soaked for 4 hours, and germinated for 48 hours under different environments, i.e., under different atmospheric pressures and oxygen content environments. The germination rate of highland barley seeds and the content of GABA in highland barley are shown in Table 3 below.

[0054] Table 3. Effects of cultivation under different environments on germination rate and GABA content

[0055]

[0056]

[0057] As shown in Table 3, different regions have different altitudes, and the atmospheric pressure and oxygen content vary greatly. By utilizing the unique natural environment of Tibet, low oxygen and low pressure, the highland barley grains can be stimulated by external factors during germination, which can significantly increase the GABA content in the highland barley. In addition, there is no need to use equipment to create low oxygen and low pressure conditions during the germination process, which can effectively reduce production costs.

[0058] Experiment 4

[0059] The processing method of Example 1 is adopted, except that: in the pulping process of step 4, the highland barley grains after the colloid mill are kept warm at different temperatures, and the content of GABA in the highland barley is different, as described in the following Table 4. The temperature of the highland barley grains after the colloid mill can reach 40-50° C., and the temperature of the highland barley grains is changed by heating or cooling, and the highland barley grains reaching a certain temperature are placed in a storage tank for insulation.

[0060] Table 4. Effects of different holding temperatures and holding times on GABA content

[0061]

[0062] As shown in Table 4, after being kept warm at 45-55°C, the increase in GAD activity is ≥12umol / g, which can effectively increase the content of GABA in highland barley. After being kept warm at 48°C, the increase in GAD activity is the largest, reaching 20.9umol / g, and this temperature can be achieved by absorbing the heat of the colloid mill equipment without additional heating, simplifying the steps and reducing energy consumption. After being kept warm at 55°C, the activity of GAD increased by 12umol / g, but this temperature needs to be heated by a heating device. Compared with Examples 1 to 4, there are more heating steps and the process is more complicated. When the temperature is less than 40°C or greater than 55°C, the activity of GAD is low and the content of GABA cannot be effectively increased. If the holding temperature is too short, GAD cannot be fully enzymatically hydrolyzed, resulting in a decrease in the content of GABA; if the holding temperature is too long, the activity of GAD is inhibited and the content of GABA cannot be effectively increased.

[0063] Experiment 5

[0064] The highland barley slurry obtained in step 4 of Example 1 was ripened and dried under different steam pressures, and the GABA content in the highland barley was different, as described in the following Table 5.

[0065] Table 5. Effect of different vapor pressures on GABA content.

[0066]

[0067] It can be seen from Table 5 that, under the same other conditions, when the vapor pressure is between 0.45 and 0.65 MPa, the low pressure stress (hypoxia stress) will cause the H in the cytoplasm of highland barley to +The concentration increases, leading to cytoplasmic acidification, which satisfies the conditions for GAD to catalyze glutamate to produce GABA, causing GABA to accumulate. At the same time, the recovery rate of cooked highland barley powder is the highest, reaching more than 85%. As the steam pressure increases or decreases, the recovery rate will decrease. When the steam pressure is 0.75MPa, the recovery rate is less than 60%; when the steam pressure is 0.35MPa, the recovery rate is 70%. Therefore, when the steam pressure is 0.45-0.65MPa, it is the best drying pressure setting. At this time, while accumulating GABA, the recovery rate of the material can be guaranteed, achieving the best economic benefits.

[0068] The above are only embodiments of the present invention. The invention is not limited to the field involved in this implementation case. The common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A processing method for increasing the GABA content of cooked highland barley flour, characterized in that: The steps include: Step 1, cleaning: weigh highland barley grains and clean them; Step 2, soaking: soaking highland barley grains in water; Step 3, germination: placing highland barley grains under low oxygen and low pressure conditions for germination; Step 4, pulping: grinding the germinated highland barley grains, and keeping them warm at 40-55° C. for 45-60 min to obtain highland barley slurry; Step 5, aging and drying: the highland barley slurry is aged and dried to obtain cooked highland barley powder rich in GABA.

2. The processing method according to claim 1, characterized in that: During the soaking process in step 2, the weight ratio of highland barley grains to water is 1:4-6.

3. The processing method according to claim 1, characterized in that: During the soaking process in step 2, the soaking temperature is 18 to 23° C., the soaking time is 2 to 6 hours, and air is introduced during the soaking process.

4. The processing method according to claim 1, characterized in that: During the germination process of step 3, the highland barley grains are placed under low oxygen and low pressure conditions with an oxygen content of 15-16% and an atmospheric pressure of 60-70 KPa for germination.

5. The processing method according to claim 1, characterized in that: During the germination process of step 3, the germination cultivation temperature is 18-23° C. and the germination cultivation time is 24-48 hours.

6. The processing method according to claim 1, characterized in that: Step 4: Grinding is performed using a colloid mill. Water is added during the colloid milling process and the colloid milling is performed at least twice.

7. The processing method according to claim 1, characterized in that: Step 5: Adiabatic steam drying is used for aging and drying, with a steam pressure of 0.45-0.65 MPa, a steam temperature of 110-130° C., and a steaming time of 4-6 min.

8. Cooked highland barley flour rich in GABA prepared by the processing method according to any one of claims 1 to 7.

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