Processing method of quinoa germ tea

Abstract

This invention belongs to the field of tea preparation and addresses the technical problems of incomplete saponin removal, easy destruction of heat-sensitive nutrients, and monotonous and easily lost flavor in existing quinoa germ tea processing. The invention discloses a processing method for quinoa germ tea. The method involves first steaming washed, soaked, and drained quinoa germ with saturated steam to obtain cooked quinoa germ; then, 5%–15% of the cooked quinoa germ is mixed with drinking water at a ratio of 1:3–5, homogenized, and then mixed with edible-grade porous starch at a ratio of 1:0.5–2 and spray-dried to obtain a composite adsorbent; the remaining cooked quinoa germ is dehydrated at 65–75°C and stir-fried for 3–5 minutes to obtain initially roasted germ; this is then mixed with the composite adsorbent and allowed to stand for 10–20 minutes, followed by roasting at 300–450W for 2–4 minutes to obtain the finished product. The quinoa germ tea prepared by this method has a mellow taste, rich aroma, and fully retained nutrients, making it suitable as a healthy caffeine-free tea substitute.

Description

Technical Field

[0001] This invention relates to the field of tea preparation. More specifically, this invention relates to a method for processing quinoa germ tea. Background Technology

[0002] In the field of tea preparation, quinoa, rich in high-quality protein, essential amino acids, dietary fiber, and various vitamins and minerals, has high nutritional value and market potential when its germ is used as a raw material for deep processing into tea substitutes. However, existing technologies for processing quinoa germ tea still face many unresolved issues in practical applications, which directly affect the quality of the final product.

[0003] Firstly, in the quinoa germ ripening process, existing techniques struggle to achieve sufficient and uniform ripening. Quinoa germ has a loose texture and is heat-sensitive. If conventional high-temperature heating is used, the outer surface of the germ is easily overheated and scorched, producing a bitter taste, while the inside fails to reach the ideal ripening level, resulting in an uneven product texture. If the heating temperature is lowered or the time is shortened, it is impossible to ensure complete ripening of the germ, which may not only result in a raw or astringent taste but may also affect subsequent processing and product stability due to incomplete ripening.

[0004] Secondly, existing processes are ineffective at preserving and enhancing the flavor compounds in quinoa germ. During processing, the flavor precursors contained in quinoa germ need to be transformed into flavor compounds with pleasant aromas through appropriate processes. However, existing processes lack targeted flavor control steps, resulting in quinoa germ tea with a single flavor profile and insufficient aroma intensity. Furthermore, volatile aroma components generated during processing are easily lost, further degrading the product's flavor quality and failing to meet consumer demands for tea flavor.

[0005] Furthermore, some water-soluble nutrients in quinoa germ are easily lost during processing, and existing processes lack effective mechanisms for their recovery and utilization. During washing, soaking, or heat treatment, water-soluble nutrients in the germ dissolve into the processing solution. If these processing solutions are discarded directly, it not only wastes nutritional resources but also reduces the nutritional value of the final product, failing to fully realize the nutritional advantages of quinoa germ.

[0006] Furthermore, quinoa germ tea prepared using existing processes suffers from insufficient flavor stability. The surface structure of processed quinoa germ particles is unstable and easily affected by environmental factors, leading to the continuous loss of flavor substances during storage. This results in rapid flavor degradation during the product's shelf life, impacting long-term quality stability and increasing the difficulty of quality control during storage and transportation.

[0007] Finally, the existing process lacks supporting treatment methods to enhance the flavor and quality of the germ. In key processing steps such as roasting, relying solely on heating is insufficient to further optimize the flavor of the germ, nor can it effectively address quality fluctuations caused by uneven heating and nutrient loss during processing. This results in poor consistency in quality between different batches, hindering stable industrial-scale production. Summary of the Invention

[0008] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0009] Another objective of this invention is to provide a processing method for quinoa germ tea, which achieves full and uniform ripening of quinoa germ through step-by-step steaming to avoid scorching and undercooking, reduces the loss of flavor substances and recovers water-soluble nutrients by using a quinoa germ composite adsorbent, and optimizes the flavor and fixes nutrients by two roasting processes. This not only enhances the flavor level, richness and nutritional value of the product, but also enhances the flavor stability and batch consistency, which is conducive to stable industrial production.

[0010] To achieve these objectives and other advantages according to the present invention, a method for processing live quinoa germ tea is provided, comprising the following steps:

[0011] S1. After washing, soaking and draining, the quinoa germ is first steamed in saturated steam at 85~90℃ for 3~5 minutes, and then steamed in saturated steam at 95~100℃ for 5~8 minutes to obtain cooked quinoa germ.

[0012] S2. Take a portion of 5% to 15% of the total weight of the cooked quinoa germ, mix it with drinking water at a mass ratio of 1:3 to 5, slurry it, homogenize it, and then mix it with food-grade porous starch at a mass ratio of 1:0.5 to 2 and spray dry it to obtain the quinoa germ composite adsorbent.

[0013] S3. Treat the remaining cooked quinoa germ from S1 at 65-75°C for 5-8 minutes to obtain dehydrated quinoa germ; stir-fry the dehydrated quinoa germ at 200-300W for 3-5 minutes to obtain the first-time stir-fried quinoa germ.

[0014] S4. Mix the first-roasted quinoa germ with 1% to 3% of the quinoa germ composite adsorbent by weight evenly, and let it stand in a sealed container for 10 to 20 minutes to obtain aged material. Roast the aged material at 300 to 450W for 2 to 4 minutes to obtain quinoa germ tea.

[0015] Preferably, in step S1, the quinoa germ after washing, soaking and draining is obtained by the following method: placing the washed quinoa germ in a soaking solution and ultrasonically treating it for 8 to 15 minutes at a power of 50 to 100 W and a frequency of 40 kHz. The soaking solution is an aqueous solution containing 0.5% to 1.5% sodium ascorbate by mass and the volume ratio of the soaking solution to the quinoa germ is 3 to 5 mL / g. After soaking, the quinoa germ is drained.

[0016] Preferably, in step S4, before allowing the uniformly mixed material to stand, a cold air curing treatment is performed, specifically as follows: the mixture is placed in a low-temperature airflow of 2~10℃ for 1~3 minutes.

[0017] Preferably, after the final roasting in step S4, the aged material is immediately transferred to a sealed container filled with a protective atmosphere, and the material temperature is controlled to slowly decrease from the roasting endpoint temperature to 35~45℃, with a cooling rate not exceeding 5℃ / min. During this process, the protective atmosphere is maintained until the material temperature reaches 35~45℃ before packaging.

[0018] Preferably, in step S2, the edible-grade porous starch undergoes a flavor-controlled release coating pretreatment before being used to prepare the composite adsorbent, specifically:

[0019] Food-grade porous starch is placed in a fluidized bed and hot air at 40-50°C is introduced. Then, a coating solution, which is an 8%-15% (w / w) aqueous solution of food-grade gelatin, is sprayed evenly onto its surface. After spraying, it is continuously fluidized and dried at 55-65°C for 20-40 minutes to obtain pretreated coated porous starch, which is then used in the preparation of the quinoa germ composite adsorbent.

[0020] Preferably, in the preparation of coated porous starch in step S2, tea polyphenols accounting for 0.05% to 0.2% of the total mass of the coating solution are also uniformly mixed into the gelatin coating solution.

[0021] Preferably, after the final stir-frying in S4, a programmed temperature and humidity alternating maturation step is included, as follows:

[0022] The quinoa germ tea was placed in a programmable temperature and humidity chamber, and within 48 hours, it was subjected to three consecutive temperature and humidity cycle programs preset by the control system, each cycle being 16 hours long.

[0023] a) Heating and Humidification Phase: Within 4 hours, the ambient temperature inside the chamber is rapidly increased from 25°C to 40°C, while the relative humidity is rapidly increased from 45% to 65%.

[0024] b) High temperature and high humidity maintenance period: Maintain at 40℃ and 65% relative humidity for 4 hours;

[0025] c) Cooling and dehumidification section: Within 4 hours, the ambient temperature inside the chamber is uniformly reduced from 40℃ to 28℃, while the relative humidity is uniformly reduced from 65% to 40%.

[0026] d) Low temperature and low humidity maintenance period: Maintain at 28℃ and 40% relative humidity for 4 hours;

[0027] After completing three full cycles of the aforementioned procedure, the product is equilibrated at 25°C and 35% relative humidity until the moisture content is ≤7%.

[0028] Preferably, in step S2, when preparing the coated porous starch, soybean lecithin, accounting for 0.1% to 0.5% of the total mass of the coating solution, is also uniformly mixed into the gelatin coating solution.

[0029] Preferably, after the programmed temperature and humidity alternating ripening step, a fluidized bed low-temperature steady-state treatment step is also included, specifically as follows: the ripened quinoa germ tea is placed in a fluidized bed, and dehumidified air with a dew point of -10°C to -15°C is used as the fluidizing medium at a temperature of 65~75°C for 15~25 minutes.

[0030] The present invention has at least the following beneficial effects:

[0031] First, through steps such as steaming, making composite adsorbents, dehydration and frying, and aging and frying, the quinoa germ is fully matured and its flavor is enhanced, thus producing quinoa germ tea with a mellow taste and rich aroma, while improving the stability and consistency of the product.

[0032] Secondly, through ultrasonic treatment and soaking in sodium ascorbate solution, impurities on the surface of quinoa germ are effectively removed and oxidation is inhibited, maintaining the freshness and nutrients of the germ, thereby extending the shelf life of the product and enhancing its hygiene and safety.

[0033] Third, the cold air curing process rapidly cools and solidifies the mixture, promoting the uniform combination of the adsorbent and quinoa germ, enhancing the aging effect, and thus making the final product more uniform and stable in flavor, and reducing quality fluctuations during processing.

[0034] Fourth, by slowly cooling in a protective atmosphere, the quinoa germ tea is prevented from absorbing moisture or oxidizing due to sudden temperature changes, effectively preserving its aroma and taste, while reducing the loss of nutrients and extending the product's shelf life.

[0035] Fifth, by pre-treating the food-grade porous starch with flavor-controlled release coating, the stability and controlled release capability of the adsorbent are enhanced, making the flavor release of quinoa germ tea more lasting and uniform during brewing, thus improving the drinking experience.

[0036] Sixth, by adding tea polyphenols to the coating solution, the antioxidant properties of the composite adsorbent are further enhanced, preventing flavor deterioration and oil oxidation, and may also bring additional health benefits, such as improving the functional value of the product.

[0037] Seventh, through a programmed temperature and humidity alternation maturation process, the natural aging process is simulated to promote the maturation and stability of the quinoa germ tea flavor, improve the taste and aroma, and precisely control the moisture content to ensure the uniformity and stability of product quality.

[0038] Eighth, by adding soybean lecithin to the coating solution as an emulsifier and stabilizer, the uniformity and adsorption performance of the coating solution are improved, the flavor controlled release effect is enhanced, and the dispersibility and processing adaptability of the composite adsorbent are improved.

[0039] Ninth, by using fluidized bed low-temperature steady-state treatment, excess moisture is further removed, the product structure is stabilized, clumping and mold are prevented, and the stability and sensory quality of quinoa germ tea during long-term storage are ensured, thereby enhancing the commercial value of the product.

[0040] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0042] This invention provides a method for processing quinoa germ tea, comprising the following steps:

[0043] S1. After washing, soaking and draining, the quinoa germ is first steamed in saturated steam at 85~90℃ for 3~5 minutes, and then steamed in saturated steam at 95~100℃ for 5~8 minutes to obtain cooked quinoa germ.

[0044] S2. Take a portion of 5% to 15% of the total weight of the cooked quinoa germ, mix it with drinking water at a mass ratio of 1:3 to 5, slurry it, homogenize it, and then mix it with food-grade porous starch at a mass ratio of 1:0.5 to 2 and spray dry it to obtain the quinoa germ composite adsorbent.

[0045] S3. Treat the remaining cooked quinoa germ from S1 at 65-75°C for 5-8 minutes to obtain dehydrated quinoa germ; stir-fry the dehydrated quinoa germ at 200-300W for 3-5 minutes to obtain the first-time stir-fried quinoa germ.

[0046] S4. Mix the first-roasted quinoa germ with 1% to 3% of the quinoa germ composite adsorbent by weight evenly, and let it stand in a sealed container for 10 to 20 minutes to obtain aged material. Roast the aged material at 300 to 450W for 2 to 4 minutes to obtain quinoa germ tea.

[0047] In the above technical solution, when processing quinoa germ tea, the raw materials are first processed. Commercially available quinoa germ is selected, washed with clean water to remove surface impurities, and then soaked in room temperature drinking water until the germ fully absorbs water. The surface water is then drained through a mesh sieve to obtain washed, soaked, and drained quinoa germ. Next, a step-by-step steaming process is performed. The drained quinoa germ is placed in a sealable steam cooking device, such as a commercially available multi-layer steam oven. Saturated steam at 85℃, 88℃, or 90℃ is first introduced into the steam oven and maintained at this temperature for 3 minutes, 4 minutes, or 5 minutes. After the first stage of steaming, without removing the quinoa germ, the steam supply is directly adjusted to raise the temperature inside the steam oven to 95℃, 98℃, or 100℃, and steaming continues for 5 minutes, 6 minutes, 7 minutes, or 8 minutes with saturated steam at this temperature. After steaming, the quinoa germ is removed, yielding cooked quinoa germ.

[0048] Next, the quinoa germ composite adsorbent was prepared. First, 5%, 10%, or 15% of the total weight of the cooked quinoa germ was extracted. This portion of cooked germ was then mixed with drinking water at a mass ratio of 1:3, 1:4, or 1:5 in a stirring pulping device. A standard food-grade pulping machine could be used. The device was started to pulp the mixture into a fine slurry. The slurry was then fed into a homogenizing device, such as a high-pressure homogenizer, to homogenize the slurry and ensure a uniform texture. Subsequently, food-grade porous starch was added to the homogenized slurry at a mass ratio of 1:0.5, 1:1, 1:1.5, or 1:2. After thorough mixing, the mixture was fed into a spray drying device, such as a centrifugal spray dryer. Appropriate inlet and outlet air temperatures were set for spray drying. The dried quinoa germ composite adsorbent was then collected.

[0049] Finally, dehydration, roasting, and aging are carried out. The remaining cooked quinoa germ from S1 is placed in a hot air drying device, such as a belt hot air dryer, with the temperature set to 65℃, 70℃, or 75℃ for 5, 6, 7, or 8 minutes to remove some moisture, resulting in dehydrated quinoa germ. The dehydrated quinoa germ is then transferred to an electric heating roasting device, such as a drum-type electric roaster, with the power adjusted to 200W, 250W, or 300W. The device is started and roasted for 3, 4, or 5 minutes to obtain initially roasted quinoa germ. 1%, 2%, or 3% of quinoa germ composite adsorbent by weight is added to the initially roasted quinoa germ, and the mixture is stirred evenly in a mixing device. The mixture is then transferred to a sealed container, such as a food-grade stainless steel airtight container, and left to stand for 10, 15, or 20 minutes to obtain aged material. Place the aged material back into the electric heating frying equipment, adjust the power to 300W, 350W, 400W or 450W, stir-fry for 2 minutes, 3 minutes or 4 minutes, and remove it after frying. This is quinoa germ tea.

[0050] Quinoa germ tea processed through the above steps is uniformly ripened without scorching or undercooking, has a rich flavor, retains nutrients well, and exhibits high consistency in quality across different batches.

[0051] The closest existing technology is the processing method for conventional grain teas (such as barley tea and brown rice tea). This type of method usually uses a process of heating and ripening once (such as direct roasting or steaming once) combined with a single stir-frying, and does not involve the preparation and use of composite adsorbents. Compared with the existing technology, the creativity of this technical solution lies in the following two aspects: First, considering the loose texture and heat sensitivity of quinoa germ, it breaks through the conventional approach of "single-time heating and cooking" in the existing technology, and adopts a step-by-step steaming process of "steaming with saturated steam at 85~90℃ for 3~5 minutes + steaming with saturated steam at 95~100℃ for 5~8 minutes". This solves the technical problem that the high temperature alone can easily lead to scorching of the germ and the low temperature for a short time can easily lead to undercooking in the germ. It achieves full and uniform cooking of quinoa germ. This process adjustment requires targeted design based on the special raw material properties of quinoa germ. Second, the existing technology does not consider the loss of flavor substances and water-soluble nutrients during the processing of grain germ. This technical solution proposes to prepare a quinoa germ composite adsorbent. By slurrying some cooked germ and combining it with edible-grade porous starch, it can both adsorb and retain the volatile flavor substances generated during the roasting process, reducing flavor loss, and recover water-soluble nutrients in the slurry, avoiding nutrient waste.

[0052] The following examples and comparative examples illustrate this.

[0053] <Example 1>

[0054] 1. Raw material processing: Take 1000g of commercially available quinoa germ, wash it 3 times with clean water (soak for 1 minute each time and rinse for 30 seconds) to remove surface impurities, soak it in room temperature drinking water for 2 hours (stir gently once every 30 minutes) until the germ has fully absorbed water, and drain the surface water through an 80-mesh nylon mesh sieve.

[0055] 2. Step-by-step steaming: Spread the drained quinoa germ evenly on the stainless steel tray of the multi-layer steam oven (the thickness of the spread is about 1cm to ensure that the steam penetrates evenly). First, introduce 88℃ saturated steam and steam for 4 minutes. Then, adjust the steam temperature to 98℃ and continue steaming for 6 minutes. Keep the steam oven sealed during the steaming process. After taking it out, let it cool naturally to room temperature to obtain cooked quinoa germ.

[0056] 3. Preparation of composite adsorbent: Take 100g of cooked quinoa germ and put it into a food-grade stainless steel pulper with 400g of drinking water. Pulverize at 3000r / min for 10min until there are no obvious particles in the slurry. Send the slurry into a high-pressure homogenizer (pressure 30MPa, temperature 40℃) for homogenization twice (1min each time). Then add 100g of corn-derived edible porous starch and stir with a paddle agitator at 500r / min for 15min until the mixture is uniform. Spray dry using a centrifugal spray dryer (inlet air temperature 180℃, outlet air temperature 80℃, feed rate 15mL / min) to collect the quinoa germ composite adsorbent.

[0057] 4. Dehydration and initial roasting: The remaining 900g of cooked quinoa germ was placed in a belt hot air dryer (wind speed 1.5m / s, hot air temperature 70℃) for 6 minutes to obtain dehydrated quinoa germ; the dehydrated quinoa germ was then transferred to a drum-type electric roaster (drum speed 15r / min) and roasted for 4 minutes with the power adjusted to 250W (samples were taken every 1 minute during the roasting process to avoid local overheating) to obtain the initial roasted quinoa germ.

[0058] 5. Aging and Secondary Roasting: Add 18g of quinoa germ composite adsorbent (2% of its weight) to the quinoa germ that has been roasted for the first time. Mix it for 5 minutes at 200r / min using a double helix mixer until there are no obvious lumps. Transfer it to a food-grade 304 stainless steel sealed container and let it stand for 15 minutes (standing temperature 25℃, relative humidity 45%). Then put it back into a drum-type electric roasting machine (drum speed 12r / min) and stir-fry for 3 minutes at 400W. After roasting, immediately take it out and spread it out to cool to room temperature to obtain the finished quinoa germ tea.

[0059] <Comparative Example 1>

[0060] Comparative Example 1 omits the step-by-step steaming process and uses a single steaming process. Specifically, except for the step of "step-by-step steaming" which is replaced by "spreading the drained quinoa germ evenly on a multi-layer steam oven tray, introducing 95°C saturated steam for 10 minutes, and then removing it and cooling it to room temperature", the other steps (raw material processing, composite adsorbent preparation, dehydration and initial roasting, aging and secondary roasting) are the same as in Example 1.

[0061] <Comparative Example 2>

[0062] Comparative Example 2 omits the preparation of the composite adsorbent and directly roasts the quinoa. Specifically, the "composite adsorbent preparation" step is omitted, and the "aging and secondary roasting" step is replaced by "directly transferring the first roasted quinoa germ into a drum-type electric roasting machine (drum speed 12r / min), adjusting the power to 400W and roasting for 3 minutes, then removing and spreading it to cool to room temperature." All other steps (raw material processing, step-by-step steaming, dehydration and first roasting) are the same as in Example 1.

[0063] <Comparative Example 3>

[0064] Comparative Example 3 illustrates the existing conventional grain tea processing technology, referencing the barley tea processing method. Specifically: 1000g of commercially available quinoa germ was taken, rinsed three times with clean water, drained through an 80-mesh sieve, and directly placed into a drum-type electric roasting machine (drum speed 15r / min). It was preheated at 150W for 5 minutes (stirring once every 2 minutes during preheating), then the power was adjusted to 300W and stir-fried for 8 minutes. After that, it was taken out and spread out to cool to room temperature to obtain the finished quinoa germ tea.

[0065] <Indicator Detection and Result Analysis>

[0066] 1. Detection Indicators and Methods

[0067] 1.1. Curing uniformity

[0068] One hundred samples were randomly selected and crushed or cut open to expose their interiors. Undercooked particles were hard, with a light yellow, glossy (or glassy) cross-section; cured particles were brittle, with a darker, less glossy, and opaque cross-section. The percentage of cured particles was recorded, and the results were repeated three times, with the average value taken.

[0069] 1.2 Scorch Rate

[0070] Randomly select 100g samples and pick out all charred particles that are significantly darker in color than normal fried particles (showing as dark brown, brownish-black or black). Weigh them and calculate the percentage of charred particles. Repeat 3 times and take the average value.

[0071] 1.3 Flavor substance retention

[0072] Static headspace-gas chromatography was used. Volatile flavor components in the sample were released into the upper part of the headspace vial by heating. After equilibrium was reached, the headspace gas was injected into the gas chromatograph, separated by a capillary column, and detected by a flame ionization detector (FID). The total peak area of ​​the total volatile components was used as an indicator of the relative content of flavor substances.

[0073] 1) Instruments and equipment

[0074] Gas chromatograph equipped with flame ionization detector (FID)

[0075] Fully automated static headspace sampler

[0076] Analytical balance (sensitivity 0.0001 g)

[0077] 20 mL headspace vials with PTFE / silicone gasket sealing caps

[0078] An airtight syringe (if manual injection is required).

[0079] 2) Chromatographic conditions

[0080] Chromatographic column: DB-5 capillary column (5% phenyl-95% dimethyl polysiloxane), 30 m × 0.25 mm × 0.25 μm

[0081] Carrier gas: High-purity nitrogen (≥99.999%), constant flow mode, flow rate 1.0 mL / min

[0082] Inlet temperature: 200 ℃; Split ratio: 10 : 1;

[0083] Column temperature program: Initial temperature 40 ℃, hold for 3 min; increase to 180 ℃ at a rate of 5 ℃ / min, hold for 5 min;

[0084] Detector (FID) temperature: 250 ℃; Hydrogen flow rate: 30 mL / min; Air flow rate: 300 mL / min; Make-up gas (nitrogen) flow rate: 25 mL / min;

[0085] 3) Headspace conditions

[0086] Sample equilibration temperature: 90 ℃; Sample equilibration time: 30.0 min; Injection needle temperature: 95 ℃; Transfer line temperature: 100 ℃; Pressurization pressure: 138 kPa (approximately 20 psi); Pressurization time: 0.50 min; Quantitative loop filling time: 0.20 min; Injection time: 1.00 min.

[0087] 4) Analysis steps

[0088] Accurately weigh 2.00 g of the quinoa germ tea sample (accurate to 0.01 g) into a 20 mL headspace vial. Immediately seal the vial with a gasketed cap to ensure airtightness. Place the vial into the headspace sample tray, set the chromatographic and headspace conditions as described above, and start the analysis. Perform three parallel determinations.

[0089] 5) Results representation

[0090] Record the total area of ​​all chromatographic peaks appearing after the solvent peak (usually after the integration start time of about 3.0 min), and take the average of 3 parallel determinations (the peak area of ​​total volatile aroma components in Table 1 below) as the flavor substance retention of the sample.

[0091] 2. Analysis of Test Samples and Results

[0092] The above-mentioned indicators of quinoa germ tea prepared in Example 1 and Comparative Examples 1-3 were measured, and the results are shown in Table 1.

[0093] Table 1. Detection results of indicators in Example 1 and Comparative Examples 1-3

[0094]

[0095] As shown in Table 1, Example 1 employs a "step-by-step steaming" method. First, the quinoa germ is steamed at a low temperature of 88℃ to allow for slow internal heating (avoiding excessive temperature differences between the inside and outside). Then, it is steamed at a high temperature of 98℃ for deep cooking. Therefore, the cooking uniformity reaches 97.5%, and the low-temperature stage effectively inhibits scorching (scorching rate is only 0.4%). Comparative Example 1, due to a single steaming (95℃ × 10 min), initially heats the germ surface too quickly, while internal heating lags behind, resulting in a cooking uniformity of only 81.3%. Furthermore, the prolonged high temperature causes the local scorching rate to rise to 2.3%. Comparative Example 3, without steaming, directly roasts the germ. At high temperatures, the germ surface rapidly chars, but the inside is not fully cooked, resulting in a cooking uniformity of only 64.5% and a scorching rate as high as 6.1%. This fully demonstrates the necessity of "step-by-step steaming" in solving the problem of "outer char and inner undercooked."

[0096] The composite adsorbent in Example 1 was made from cooked germ slurry and porous starch. The porous structure of the starch can adsorb volatile aroma components (such as pyrazines, aldehydes, and other characteristic aroma substances of grains) generated during roasting, resulting in a total volatile aroma component peak area of ​​85632. Simultaneously, water-soluble vitamin B1 in the slurry was fixed by the porous starch and re-attached when mixed with the germ, achieving a retention rate of 81.8%. In Comparative Example 2, lacking the composite adsorbent, volatile aroma substances were lost with the hot air, reducing the peak area to 51368. Vitamin B1 dissolved and was lost during roasting, resulting in a retention rate of only 64.2%. Comparative Example 3, without steaming and the adsorbent step, directly destroyed some vitamin B1 at high temperatures, and a large amount of aroma substances were lost, resulting in the lowest values ​​for both indicators. This confirms the flavor and nutrient retention effect of the "composite adsorbent."

[0097] In summary, this invention, through a combination of "stepwise steaming + composite adsorbent" processes, addresses the core pain points of existing quinoa germ tea processing. The test data and process logic are highly matched, and its technical effect is significantly better than conventional processes.

[0098] In another technical solution, in step S1, the quinoa germ after washing, soaking and draining is obtained by the following method: the washed quinoa germ is placed in a soaking solution and ultrasonically treated for 8 to 15 minutes under the conditions of power 50~100W and frequency 40kHz. The soaking solution is an aqueous solution containing sodium ascorbate at a mass-volume ratio of 0.5%~1.5%, and the volume-mass ratio of the soaking solution to the quinoa germ is 3~5 mL / g. After soaking, the germ is drained.

[0099] In the above technical solution, when processing quinoa germ tea, the raw materials are first processed. Commercially available quinoa germ is selected, washed with clean water to remove surface impurities, and then placed in a food-grade container. A soaking solution is added to cover the surface of the germ. The soaking solution can be an aqueous solution containing 0.5%, 1.0%, or 1.5% sodium ascorbate by mass / volume. The volume-to-mass ratio of the soaking solution to the quinoa germ can be set to 3 mL / g, 4 mL / g, or 5 mL / g. The container containing the mixture is then placed in an ultrasonic device. This device can be a commercially available food-grade ultrasonic cleaner. The power of the ultrasonic device can be adjusted to 50W, 75W, or 100W, with a fixed frequency of 40kHz. Under these conditions, ultrasonic treatment is continued for 8 minutes, 12 minutes, or 15 minutes. After ultrasonic treatment, the surface moisture is drained through an 80-mesh nylon screen, yielding the washed, soaked, and drained quinoa germ.

[0100] The closest existing technology is the conventional processing method for quinoa germ tea. This type of process typically only uses water washing or ordinary soaking to remove impurities during the raw material treatment stage, without specifically addressing the removal of saponins from the surface of quinoa germ and oxidation protection. Compared with this existing technology, the advantages of this technical solution are as follows: Existing technologies do not adequately address the problems of incomplete removal of saponins from the surface of quinoa germ and easy oxidation during processing, leading to quality degradation. This technical solution, based on the characteristics of quinoa germ, innovatively adopts a combination of "soaking in sodium ascorbate aqueous solution + ultrasonic treatment." Sodium ascorbate effectively inhibits germ oxidation, while ultrasonic treatment (50~100W, 40kHz) enhances the dissolution and stripping effect of the soaking solution on saponins through vibration. Furthermore, the limited liquid-to-material ratio (3~5 mL / g) and ultrasonic time (8~15min) ensure effective saponin removal while avoiding damage to the germ. This targeted process design breaks through the traditional single-mode raw material processing, optimizing from multiple dimensions such as impurity removal, bitterness removal, and antioxidant protection, effectively compensating for the shortcomings of existing technologies and bringing about a significant quality improvement.

[0101] The technical effects will be illustrated below through specific embodiments and comparative examples.

[0102] <Example 2>

[0103] 1. Raw material processing: Take 1000g of commercially available quinoa germ, wash it three times with clean water to remove surface impurities, and place it in a soaking solution for ultrasonic treatment. The soaking solution is an aqueous solution containing 0.8% sodium ascorbate by mass and the volume ratio of the soaking solution to the quinoa germ is 4 mL / g. The ultrasonic equipment is a conventional food-grade ultrasonic cleaner, set with a power of 75W and a frequency of 40kHz, and continuously ultrasonically treated for 12 minutes. After ultrasonic treatment, drain the surface water through an 80-mesh nylon screen to obtain the cleaned, soaked and drained quinoa germ.

[0104] 2. Step-by-step steaming: Place the drained quinoa germ into a multi-layer steam oven, spread it evenly on a stainless steel tray (1cm thick), first pass in 88℃ saturated steam for 4 minutes, then adjust the steam temperature to 98℃ and continue steaming for 6 minutes, then remove to obtain cooked quinoa germ.

[0105] 3. Preparation of composite adsorbent: Take 100g of cooked quinoa germ and put it into a food-grade pulper with 400g of drinking water and pulp for 10min. The pulp is homogenized twice by a 30MPa high-pressure homogenizer. Add 100g of corn-derived edible-grade porous starch (mass ratio 1:1) and stir evenly. Spray dry using a centrifugal spray dryer (inlet air temperature 180℃, outlet air temperature 80℃) and collect the quinoa germ composite adsorbent.

[0106] 4. Dehydration and initial roasting: The remaining 900g of cooked quinoa germ is placed in a belt hot air dryer and treated at 70℃ for 6 minutes to dehydrate. Then it is transferred to a drum-type electric roaster and roasted at 250W power for 4 minutes to obtain the initial roasted quinoa germ.

[0107] 5. Aging and secondary roasting: Add 18g of compound adsorbent to the quinoa germ that has been roasted for the first time, mix well, transfer to a food-grade stainless steel sealed container and let stand for 15 minutes, then put it into a drum-type electric roasting machine and stir-fry for 3 minutes at 400W power, and take it out to obtain the finished quinoa germ tea.

[0108] <Comparative Example 4>

[0109] Comparative Example 4 was performed without sodium ascorbate, using only ultrasonic soaking in water. Specifically, except for the soaking solution being replaced with water (without sodium ascorbate) in the "raw material treatment" step, all other operations (ultrasonic power 75W, frequency 40kHz, treatment time 12min, liquid-to-material ratio 4mL / g and all subsequent steps) were the same as in Example 2.

[0110] <Indicator Detection and Result Analysis>

[0111] 1. Detection indicators and methods.

[0112] 1.1 Saponin Removal Rate

[0113] The determination was performed using high-performance liquid chromatography (HPLC). The specific method is as follows:

[0114] Instrumentation: High performance liquid chromatograph, equipped with a diode array detector (DAD).

[0115] Chromatographic conditions: Column: C18 reversed-phase column (size: 4.6 mm × 250 mm, 5 μm);

[0116] Mobile phase: Acetonitrile: 0.1% phosphoric acid aqueous solution = 35:65 (v / v);

[0117] Flow rate: 1.0 mL / min; column temperature: 30℃; detection wavelength: 205 nm; injection volume: 10 μL.

[0118] Measurement and calculation: The saponin content in raw materials and finished products is calculated by quantification using the external standard method, and the saponin removal rate is calculated accordingly.

[0119] 1.2 Peroxide value

[0120] The peroxide value of the finished product was tested according to GB 5009.227-2016 "National Food Safety Standard - Determination of Peroxide Value in Food". The test was repeated 3 times and the average value was taken.

[0121] 1.3. Vitamin B1 retention rate: Same as above.

[0122] 2. Analysis of Test Samples and Results

[0123] The above-mentioned indicators of quinoa germ tea prepared in Example 2 and Comparative Example 4 were measured, and the results are shown in Table 2.

[0124] Table 2. Detection results of indicators in Example 2 and Comparative Example 4

[0125]

[0126] As shown in Table 2, Example 2 had the lowest peroxide value and the highest vitamin B1 retention rate because sodium ascorbate inhibits germ oxidation, and the ultrasonic treatment did not destroy the nutrients. Comparative Example 4, without sodium ascorbate, showed increased oxidation, with the peroxide value rising to 0.64 mmol / kg, resulting in greater nutrient loss. This demonstrates the rationality of the ultrasonic parameters and sodium ascorbate soaking solution specified in this technical solution.

[0127] This technical solution addresses the problems of incomplete removal of quinoa germ saponins, easy oxidation, and easy nutrient loss through a raw material treatment method of "ultrasonic treatment + sodium ascorbate soaking solution". The technical effect is significantly better than that of processes without this limitation, and its superiority is fully supported by experimental data.

[0128] In another technical solution, in step S4, before the uniformly mixed material is allowed to stand, a cold air curing treatment is performed, specifically as follows: the mixture is placed in a low-temperature airflow of 2~10℃ for 1~3 minutes.

[0129] In the above technical solution, during the processing of quinoa germ tea, after the initial roasting and uniform mixing of quinoa germ and quinoa germ composite adsorbent are completed, the mixture is transferred to a cold air treatment device. This device can be a commercially available food-grade cold air dryer or a low-temperature airflow conveyor. The air inlet of the device can be equipped with a filter to ensure clean airflow. The temperature of the cold air treatment can be set to 2℃, 6℃, or 10℃, allowing the mixture to be continuously treated in this low-temperature airflow for 1 minute, 2 minutes, or 3 minutes to ensure that the overall temperature of the material rapidly drops to the low-temperature range, completing the cold air solidification treatment.

[0130] The mixture, after being cured by cold air, is then transferred to a sealed container. This container can be a food-grade stainless steel or glass airtight container. The container should be cleaned and dried beforehand, and its location should be far from high-temperature and humid environments to ensure the ambient temperature remains stable at around 25°C during the settling process. The mixture is then left to stand in the sealed container for 10, 15, or 20 minutes to obtain aged material. During this settling period, the container must be kept sealed to prevent outside air from entering and causing the material to absorb moisture or lose flavor. Subsequent final roasting and other steps for the aged material are the same as described above.

[0131] By using cold air curing, the composite adsorbent can quickly combine and solidify with the first roasted quinoa germ, preventing the adsorbent from falling off or being unevenly distributed during the static process of the mixture. This results in a more stable aging effect and better flavor uniformity and quality consistency in the final product.

[0132] The closest existing technology is the conventional processing method for quinoa germ tea or grain tea. This type of process typically involves direct static aging after mixing the materials, without a dedicated cold-air curing step. Compared to this existing technology, the advantages of this technical solution are as follows: Existing technologies fail to recognize that when the mixture is left to stand at room temperature, the bond between the adsorbent and the germ particles is not tight enough, leading to uneven distribution and affecting the aging effect and final product quality. This technical solution, based on the bonding characteristics of the adsorbent and germ, adds a cold-air curing step of "2~10℃ low-temperature airflow treatment for 1~3 minutes." This step rapidly lowers the temperature of the mixture, promoting rapid adhesion and curing of the adsorbent to the surface of the germ particles. This prevents the adsorbent from detaching or migrating due to high material temperatures during static aging. Furthermore, the limited temperature and time range ensures curing effectiveness while avoiding adverse effects of low temperatures on the germ flavor. This refined design for pre-aging material treatment is a targeted optimization combining the principles of adsorption and processing requirements, effectively compensating for the shortcomings of existing technologies and bringing about a tangible quality improvement.

[0133] In another technical solution, immediately after the final roasting in step S4, the aged material is transferred to a sealed container filled with a protective atmosphere, and the material temperature is controlled to slowly decrease from the final roasting temperature to 35~45℃, with a cooling rate not exceeding 5℃ / min. During this process, the protective atmosphere is maintained until the material temperature reaches 35~45℃, and then it is packaged.

[0134] In the above technical solution, after the final roasting is completed, the high-temperature material is immediately transferred to a sealed container filled with a protective atmosphere. This sealed container can be a food-grade stainless steel jacketed tank with temperature control. The container can be equipped with a temperature sensor, pressure gauge, and protective atmosphere inlet to ensure real-time temperature monitoring and atmosphere stability. The protective atmosphere can be food-grade nitrogen, food-grade carbon dioxide, or a mixture of both (mixing volume ratio 1:1). Before introducing the protective atmosphere, some air is evacuated from the container using a vacuum pump, and then the protective atmosphere is introduced until the pressure inside the container reaches 0.01MPa~0.02MPa, ensuring that the material is completely within the protective atmosphere environment. After the material is introduced, the container's temperature control system is activated to begin cooling. The cooling rate is adjusted by circulating cooling water through the jacket, and can be controlled at 2℃ / min, 3℃ / min, or 5℃ / min, never exceeding 5℃ / min. Simultaneously, the material temperature is continuously monitored to ensure it slowly decreases from the final roasting temperature (approximately 110℃~130℃) to 35℃, 40℃, or 45℃. During the cooling process, a protective atmosphere is replenished every 1 minute through the air inlet to maintain a stable pressure inside the container at 0.01MPa~0.02MPa, preventing atmosphere leakage and oxidation.

[0135] Once the material temperature reaches the target range of 35~45℃, immediately open the sealed container and quickly transfer the material to the packaging process. Food-grade automatic packaging machines can be used, and PET / PE composite film bags can be selected as the packaging material. Each bag should be pre-packaged in 25g or 50g portions. After packaging, the final quinoa germ tea product is obtained.

[0136] This technical solution uses a protective atmosphere to slowly cool the food immediately after frying, which can prevent oxidation and deterioration caused by the high-temperature material coming into contact with air. At the same time, slow cooling can prevent uneven crispness or cracking of the material due to excessive temperature difference, so that the flavor of the final product is more fully preserved, the degree of oxidation is lower, and the crispness and consistency of the taste are better.

[0137] In another technical solution, in step S2, the edible-grade porous starch undergoes a flavor-controlled release coating pretreatment before being used to prepare the composite adsorbent, specifically:

[0138] Food-grade porous starch is placed in a fluidized bed and hot air at 40-50°C is introduced. Then, a coating solution, which is an 8%-15% (w / w) aqueous solution of food-grade gelatin, is sprayed evenly onto its surface. After spraying, it is continuously fluidized and dried at 55-65°C for 20-40 minutes to obtain pretreated coated porous starch, which is then used in the preparation of the quinoa germ composite adsorbent.

[0139] In the above technical solution, before preparing the quinoa germ composite adsorbent, the edible porous starch is first subjected to flavor-controlled release coating pretreatment. Firstly, edible porous starch is selected, with a particle size of 80 mesh, 100 mesh, or 120 mesh. This raw material can be obtained from conventional food additive suppliers. The edible porous starch is then fed into a fluidized bed device, which can be either an intermittent or continuous fluidized bed. The hot air inlet of the device can be installed at the bottom of the fluidized bed, and a hot air filter can be installed at the front end of the hot air inlet to filter impurities in the air and ensure clean hot air. The coating liquid spraying device can be a pressure atomizing nozzle, installed at the upper position inside the fluidized bed to ensure uniform spraying of the coating liquid onto the starch surface. The temperature control system is linked to the heating components of the fluidized bed to regulate the temperature inside the device in real time.

[0140] Start the fluidized bed and introduce hot air at a temperature that can be set to 40℃, 45℃, or 50℃. The air velocity can be controlled at 1.2m / s to 1.5m / s to fluidize the edible-grade porous starch within the fluidized bed. Simultaneously prepare a coating solution, which is an aqueous solution of edible-grade gelatin. Type A or Type B gelatin can be selected, with a gel strength of 150 Bloom to 250 Bloom. Dissolve the edible-grade gelatin in drinking water to prepare a coating solution with a mass concentration of 8%, 12%, or 15%. Dissolution can be aided by water bath heating, with the heating temperature controlled at 50℃ to 60℃, until the gelatin is completely dissolved and the solution is free of obvious particles.

[0141] The prepared coating solution is evenly sprayed onto the surface of the fluidized food-grade porous starch using a fluidized bed coating spraying device. The spraying rate can be controlled between 5 mL / min and 8 mL / min to ensure that each starch granule is covered with a uniform coating solution. After spraying, the temperature of the fluidized bed is adjusted to 55℃, 60℃, or 65℃, while maintaining a constant hot air velocity. Fluidized drying continues for 20 min, 30 min, or 40 min. During the drying process, the state of the starch granules is observed in real time through the observation window to prevent clumping. After drying, the fluidized bed operation is stopped, and the treated starch is removed. This is the coated porous starch pretreated with flavor controlled-release coating, which can be used in the preparation of quinoa germ composite adsorbents.

[0142] The technical effects of this technical solution will be illustrated below through specific embodiments and comparative examples.

[0143] <Example 3>

[0144] 1. Pretreatment of Edible Porous Starch: Edible porous starch (100 mesh particle size) from corn is selected and fed into an intermittent fluidized bed. The hot air inlet of the fluidized bed is installed at the bottom of the equipment, with a 5μm precision hot air filter at the front end; a pressure atomizing nozzle (0.5mm orifice) is installed inside the fluidized bed, aligned with the center of the starch fluidization area; a temperature control system probe is embedded in the side wall of the fluidized bed cavity to monitor the temperature inside the cavity in real time. The fluidized bed is started, and 45℃ hot air (wind speed 1.4m / s) is introduced to make the corn porous starch uniformly fluidized in the fluidized bed. During the fluidization process, the observation is made through the equipment observation window to ensure that the starch particles do not agglomerate or adhere to the wall.

[0145] 2. Preparation of Coating Solution: Type A edible gelatin (gel strength 200 Bloom, purchased from a conventional food ingredient supplier) conforming to GB 6783-2013 "Food Additives Gelatin" standard was selected and dissolved in drinking water. The drinking water was heated to 55℃, and Type A gelatin was slowly added while stirring at a rate of 300 r / min for 20 minutes until the gelatin was completely dissolved and no visible particles were observed. A 12% (w / w) edible gelatin aqueous solution was prepared as the coating solution. After preparation, the coating solution was kept at 50℃ for later use to prevent the gelatin from cooling and solidifying.

[0146] 3. Coating and Drying: The pre-treated coating solution is evenly sprayed onto the surface of the fluidized corn porous starch through a pressure atomizing nozzle of the fluidized bed at a rate of 7 mL / min. During spraying, the temperature inside the fluidized bed is maintained at a stable 45℃ to prevent temperature fluctuations that could cause the coating solution to solidify and clog the nozzles. After spraying, the heating system of the fluidized bed is adjusted to raise the temperature inside the equipment to 60℃, maintaining a constant hot air velocity of 1.4 m / s. Fluidized drying continues for 30 minutes. During the drying process, a small amount of starch sample is taken every 5 minutes through the sampling port to ensure that the starch granules are dry and free of adhesion. After drying, the fluidized bed heating system is turned off, and ambient air is continuously circulated for cooling for 10 minutes. Once the starch temperature has dropped to room temperature, it is removed, which is the coated porous starch pretreated with flavor-controlled release coating.

[0147] 4. Subsequent processing of quinoa germ tea: Take 10% of mature quinoa germ (obtained by steaming with saturated steam at 88℃ for 4 minutes and saturated steam at 98℃ for 6 minutes), mix it with drinking water at a mass ratio of 1:4, put it into a food-grade pulper (speed 3000 r / min) and pulp for 10 minutes until the pulp is fine, then homogenize it twice with a high-pressure homogenizer (pressure 30MPa), and then mix it with the above-mentioned coated porous starch at a mass ratio of 1:1, put it into a centrifugal spray dryer (inlet air temperature 180℃, outlet air temperature 80℃) and spray dry to obtain quinoa germ composite adsorbent. The remaining ripe quinoa germ is dehydrated in a 70℃ hot air dryer for 6 minutes, then transferred to a drum-type electric roaster (250W power) and roasted for 4 minutes to obtain the first roasted germ. 2% of the germ is added to the roasted germ, mixed evenly, and then left to stand in a sealed container at 25℃ for 15 minutes. Finally, it is roasted in a drum-type electric roaster (400W power) for 3 minutes to obtain the finished quinoa germ tea.

[0148] <Comparative Example 5>

[0149] Except for "the corn-derived edible-grade porous starch is not pretreated with flavor-controlled release coating, and the composite adsorbent is prepared directly using 100-mesh corn-derived edible-grade porous starch", the other steps (quinoa germ washing and soaking, stepwise steaming at 85-90℃ saturated steam for 3-5 min + 95-100℃ saturated steam for 5-8 min, composite adsorbent preparation, dehydration at 65-75℃ for 5-8 min, initial roasting at 200-300W for 3-5 min, mixing with composite adsorbent and standing for 10-20 min, and final roasting at 300-450W for 2-4 min) are the same as in Example 3.

[0150] <Indicator Detection Methods>

[0151] 1. Flavor Compound Release Duration: Static headspace-gas chromatography was used for determination. Simulating the actual brewing process, the persistence of flavor release was characterized by measuring the decay of the total amount of volatile flavor components in the headspace of quinoa germ tea at different time points in a specific volume of hot water. The specific method is as follows:

[0152] 1) Instruments and equipment

[0153] In addition to the instruments and equipment used in the aforementioned method for determining the retention of flavor substances, a constant temperature water bath or a temperature-controlled electric kettle, a covered glass brewing cup (250 mL), and a precision pipette are also required.

[0154] 2) Brewing and Sampling

[0155] Accurately weigh 5.00 g of the quinoa germ tea sample (accurate to 0.01 g) and place it in a 250 mL covered glass. Quickly add 200 mL of ultrapure water that has been boiled and cooled to 95 ± 1 ℃, immediately tighten the lid, and start timing. At three time points after brewing—0 minutes (immediately), 10 minutes, and 30 minutes—accurately pipette 5.0 mL of the upper tea infusion and quickly transfer it to a 20 mL headspace vial, then immediately seal it.

[0156] 3) Chromatographic and headspace conditions

[0157] Chromatographic conditions: Same as the aforementioned method for determining the retention of flavor compounds.

[0158] Headspace conditions: Same as the aforementioned method for determining the retention of flavor compounds.

[0159] 4) Analysis steps

[0160] Headspace vials prepared at three time points (0, 30, 60 min) were analyzed under the same chromatographic and headspace conditions as described above. Each sample at each time point was analyzed in triplicate.

[0161] 5) Calculation and representation of results

[0162] Calculate the average peak area of ​​total volatile aroma components of tea samples at three time points (i.e., the peak area of ​​total volatile aroma components at 0 min of brewing, 30 min of brewing, and 60 min of brewing in Table 3 below).

[0163] 2. Vitamin B1 adsorption capacity of composite adsorbent: Referring to the aforementioned "Vitamin B1 retention rate" test method (GB5009.84-2016 "National Food Safety Standard for Determination of Vitamin B1 in Food"), the adsorption capacity of the composite adsorbent on vitamin B1 in cooked quinoa germ slurry was calculated (adsorption capacity = initial vitamin B1 content in slurry - vitamin B1 content in residual liquid after spray drying), and the average value was taken after repeating 3 times.

[0164] 3. Aroma retention rate during product storage: After sealing the sample, store it in a constant temperature and humidity chamber at 25℃ and 60% relative humidity for 30 days. Measure the peak area of ​​total volatile aroma components before storage and after 30 days of storage (the detection method is the same as the 0-minute detection step in "Flavor Substance Release Durability"). Calculate the aroma retention rate (aroma retention rate = peak area after storage / peak area before storage × 100%). Repeat 3 times and take the average value.

[0165] <Indicator Detection Results>

[0166] The above-mentioned indicators of quinoa germ tea from Example 3 and Comparative Example 5 were measured, and the results are shown in Table 3.

[0167] Table 3. Detection results of Example 3 and Comparative Example 5

[0168]

[0169] Table 3 shows that the peak areas of the total volatile aroma components in Example 3 and Comparative Example 5 are similar at 0 min of brewing. This is because the coating pretreatment only affects the flavor release rate and does not change the initial adsorption amount. At 30 min and 60 min of brewing, the peak area of ​​Example 3 decreased less than that of Comparative Example 5, indicating that the flavor decay rate of Example 3 is significantly slower than that of Comparative Example 5. This is because the gelatin coating of the present invention forms a slow-release layer on the surface of the porous starch, which slows down the dissolution and release rate of flavor substances in the tea soup. In contrast, the uncoated porous starch of Comparative Example 5 easily dissolves and loses its adsorbed flavor substances quickly.

[0170] Secondly, regarding the adsorption efficiency of the composite adsorbent: the vitamin B1 adsorption capacity of Example 3 is higher than that of Comparative Example 5. This is because the colloidal properties of gelatin can form a weak binding effect with water-soluble vitamin B1, and the coating process does not block the pores of the porous starch (the drying temperature of 60°C is lower than the denaturation temperature of gelatin, thus avoiding pore closure). This is equivalent to adding the auxiliary adsorption of gelatin on the basis of the original pore adsorption of starch, thus increasing the adsorption capacity.

[0171] Finally, regarding the stability of flavor during product storage: Example 3 had a higher aroma retention rate after 30 days of storage than Comparative Example 5. This is because the gelatin coating can prevent oxygen in the air from contacting the flavor substances adsorbed inside the porous starch, reducing the oxidative degradation of flavor substances (such as the oxidation of aldehydes and pyrazines). In contrast, the uncoated starch in Comparative Example 5 had flavor substances that easily reacted with oxygen, resulting in greater aroma loss after storage.

[0172] In summary, the flavor-controlled release coating pretreatment process of the present invention achieves the effects of "flavor slow release, adsorption enhancement, and storage aroma preservation" through gelatin coating, and significantly improves product quality compared with the control group that did not use this process.

[0173] In another technical solution, when preparing coated porous starch in step S2, tea polyphenols accounting for 0.05% to 0.2% of the total mass of the coating solution are also uniformly mixed into the gelatin coating solution.

[0174] In the above technical solution, the preparation of the coating solution is optimized during the preparation of coated porous starch according to the aforementioned steps to achieve uniform mixing of tea polyphenols and improve the adsorbent performance. Firstly, food-grade tea polyphenols (purity ≥98%, catechin content ≥80%, purchased from a conventional food additive supplier) are selected. This raw material is commonly used as a natural antioxidant in food processing, and its safety and stability have been verified by the industry.

[0175] Next, the coating solution was prepared: Following the aforementioned requirements, food-grade gelatin was selected and dissolved in drinking water. The drinking water was heated to 55°C, and the gelatin was slowly added while stirring at 300 rpm for 20 minutes until completely dissolved, forming a 12% (w / w) gelatin aqueous solution. Then, food-grade tea polyphenols were added to this solution, with the amount controlled at 0.1% of the total mass of the coating solution (i.e., 0.1g of tea polyphenols added to 100g of gelatin aqueous solution). Stirring was continued at 300 rpm for 18 minutes, maintaining the solution temperature at 50°C to ensure uniform dispersion of the tea polyphenols without precipitation, ultimately yielding a coating solution containing tea polyphenols. Subsequent coating and drying steps were the same as described above. The final product was tea polyphenol-modified coated porous starch, which was used in the subsequent preparation of quinoa germ composite adsorbent.

[0176] The addition of tea polyphenols can inhibit the oxidation of unsaturated fatty acids in quinoa germ in the coated porous starch and composite adsorbent, reducing the production of rancidity and lowering the peroxide value of the composite adsorbent after one month of storage. At the same time, tea polyphenols can form a weak interaction with the adsorbed volatile flavor substances, slowing down their oxidative degradation. This results in an increased retention rate of total volatile aroma components in the final quinoa germ tea after storage at 25℃ and 60% relative humidity for 30 days, extending the flavor stability period. Furthermore, the selected addition of 0.05%~0.2% tea polyphenols is relatively low and evenly dispersed in the gelatin coating layer without clogging the pores of the porous starch. The adsorption capacity of the composite adsorbent for water-soluble nutrients such as vitamin B1 is basically unaffected. The slight tea flavor of the tea polyphenols can also blend with the grain flavor of quinoa germ without producing off-flavors, ensuring the harmony of the tea soup's taste.

[0177] The technical effects of this technical solution will be demonstrated below through specific embodiments.

[0178] <Example 4>

[0179] 1. Preparation of coating solution: Type A food-grade gelatin was selected. 12g of gelatin was added to 88g of drinking water. The mixture was placed in a 55℃ water bath and stirred at 300r / min for 20min until the gelatin was completely dissolved, forming a 12% (w / w) gelatin aqueous solution. Then, 0.1g of food-grade tea polyphenols (purity ≥98%, catechin content ≥80%) were added to the solution, and stirring was continued at 300r / min for 18min, maintaining the solution temperature at 50℃ during this period to ensure uniform dispersion of tea polyphenols without precipitation, thus obtaining a coating solution containing tea polyphenols.

[0180] 2. Preparation of Coated Porous Starch: Edible-grade porous starch (100 mesh particle size) from corn was selected and fed into an intermittent fluidized bed. The hot air inlet of the fluidized bed was installed at the bottom of the equipment (with a 5μm precision filter at the front end). A pressure atomizing nozzle (0.5mm orifice) was installed inside the fluidized bed (aligned with the center of the starch fluidization area). The temperature control system probe was embedded in the side wall of the chamber. The fluidized bed was started, and 45℃ hot air (wind speed 1.4m / s) was introduced to make the starch uniformly fluidized. The above-mentioned coating solution containing tea polyphenols was sprayed at a rate of 7mL / min. After spraying, the temperature of the fluidized bed was raised to 60℃, and fluidized drying was continued for 30min. After cooling to room temperature, coated porous starch containing tea polyphenols was obtained.

[0181] 3. Quinoa germ tea processing: Prepare a composite adsorbent according to the steps in Example 1 (mix 10% of ripe quinoa germ with drinking water at a ratio of 1:4, homogenize, and then mix with the above-mentioned coated porous starch containing tea polyphenols at a ratio of 1:1 and spray dry). Subsequently, dehydrate at 70℃ for 6 min, first roast at 250W for 4 min, mix with the composite adsorbent and let stand for 15 min, and finally roast at 400W for 3 min to obtain the finished quinoa germ tea.

[0182] <Indicator Detection Methods>

[0183] 1. Peroxide value of composite adsorbent

[0184] Referring to GB 5009.227-2016 "National Food Safety Standard - Determination of Peroxide Value in Food", the peroxide value of the composite adsorbent was tested after being stored at 25℃ and 60% relative humidity for one month. The test was repeated three times and the average value was taken.

[0185] 2. Aroma retention rate during product storage

[0186] Same as above.

[0187] 3. Vitamin B1 adsorption capacity of the composite adsorbent

[0188] Same as above. Calculate the adsorption capacity of the composite adsorbent for vitamin B1 in the mature quinoa germ slurry (adsorption capacity = initial vitamin B1 content in the slurry - vitamin B1 content in the residual liquid after spray drying), repeat 3 times and take the average value.

[0189] <Indicator Detection Results>

[0190] The quinoa germ teas from Examples 3 and 4 were tested, and the specific results are shown in Table 4.

[0191] Table 4. Measurement results of Examples 3-4

[0192]

[0193] As shown in Table 4, the peroxide value of the composite adsorbent in Example 4 after storage for 1 month was significantly lower than that in the comparative example. This is because the phenolic hydroxyl groups of tea polyphenols can remove free radicals generated by the oxidation of oils in the adsorbent, inhibit the oxidation reaction process, and reduce the generation of peroxide products. In contrast, the comparative example did not have the protection of tea polyphenols, and the oils were easily oxidized, leading to an increase in the peroxide value. This proves that tea polyphenols can effectively improve the oxidative stability of the adsorbent.

[0194] Example 4: The aroma retention rate of the product after 30 days of storage was higher than that of the comparative example. This is because tea polyphenols form a weak interaction with the adsorbed volatile flavor substances (such as pyrazines and aldehydes), which slows down the contact between flavor substances and oxygen and oxidative degradation. In contrast, the flavor substances in the comparative example are easily oxidized and lost, indicating that tea polyphenols can enhance the flavor stability of the product during storage.

[0195] The adsorption capacity of Example 4 was basically the same as that of the comparative example. Because the amount of tea polyphenols added was low and they were evenly dispersed in the gelatin layer, they did not block the pores of the porous starch and did not affect its adsorption capacity for water-soluble nutrients. This verified that the addition of tea polyphenols would not damage the core function of the adsorbent.

[0196] In another technical solution, after the final stir-frying in S4, a programmed temperature and humidity alternating maturation step is also included, as follows:

[0197] The quinoa germ tea was placed in a programmable temperature and humidity chamber, and within 48 hours, it was subjected to three consecutive temperature and humidity cycle programs preset by the control system, each cycle being 16 hours long.

[0198] a) Heating and Humidification Phase: Within 4 hours, the ambient temperature inside the chamber is rapidly increased from 25°C to 40°C, while the relative humidity is rapidly increased from 45% to 65%.

[0199] b) High temperature and high humidity maintenance period: Maintain at 40℃ and 65% relative humidity for 4 hours;

[0200] c) Cooling and dehumidification section: Within 4 hours, the ambient temperature inside the chamber is uniformly reduced from 40℃ to 28℃, while the relative humidity is uniformly reduced from 65% to 40%.

[0201] d) Low temperature and low humidity maintenance period: Maintain at 28℃ and 40% relative humidity for 4 hours;

[0202] After completing three full cycles of the aforementioned procedure, the product is equilibrated at 25°C and 35% relative humidity until the moisture content is ≤7%.

[0203] In the above technical solution, after the final roasting is completed, the obtained quinoa germ tea undergoes a programmed temperature and humidity alternating ripening process. First, a programmable temperature and humidity chamber (with a temperature control accuracy of ±0.5℃ and humidity of ±2%, purchased from a conventional laboratory equipment supplier) is selected. This equipment needs to be cleaned and disinfected in advance to ensure that there are no odors or impurities remaining inside the chamber. The temperature and humidity sensor probe of the temperature and humidity chamber is installed in the middle of the inner side of the chamber to accurately monitor the environmental parameters inside the chamber. At the same time, three breathable trays for placing samples are placed inside the chamber (the trays are made of food-grade stainless steel with a 2mm aperture to avoid sample accumulation affecting the uniformity of temperature and humidity contact).

[0204] The samples were then placed: 1000g of the final roasted quinoa germ tea was evenly spread in 3 breathable trays, with the thickness of the material in each tray controlled at 1.5cm to ensure that there were no obvious lumps in the sample layer. The trays were then placed on the 3-layer shelf in the constant temperature and humidity chamber (the distance between each shelf was 15cm to ensure smooth air circulation in the chamber), the chamber door was closed and the equipment was started.

[0205] The curing process is performed according to a preset three-cycle program of continuous temperature and humidity, each cycle lasting 16 hours, with the three cycles completed within 48 hours: 1) Temperature and humidity rise phase (4 hours): The temperature and humidity chamber is controlled by a system that sets the temperature to rise uniformly from an initial 25°C to 40°C at a rate of (40-25)°C / 4h = 3.75°C / h, while the relative humidity rises uniformly from 45% to 65% at a rate of (65-45)% / 4h = 5% / h. The temperature and humidity inside the chamber are monitored in real time during the process to ensure that the deviation does not exceed the control accuracy range; 2) High temperature and high humidity maintenance phase (4 hours): The temperature and humidity reach the set temperature and humidity level. After reaching 40℃ and 65%, maintain this parameter stable for 4 hours, recording temperature and humidity data every 30 minutes during this period to avoid parameter fluctuations caused by equipment failure; 3) Cooling and dehumidification stage (4 hours): Set the temperature to drop uniformly from 40℃ to 28℃, with a cooling rate of (40-28)℃ / 4h=3℃ / h, and the relative humidity to drop uniformly from 65% to 40%, with a dehumidification rate of (65-40)% / 4h=6.25% / h, to ensure that the temperature and humidity change synchronously and stably; 4) Low temperature and low humidity maintenance stage (4 hours): After the temperature and humidity reach 28℃ and 40%, maintain this parameter stable for 4 hours to complete a complete cycle.

[0206] After all three cycles are completed, open the temperature and humidity chamber door, remove the sample tray, and transfer the quinoa germ tea to a temperature and humidity environment of 25°C and 35% relative humidity (another small temperature and humidity chamber can be used) for equilibration. During this period, the moisture content of the sample is measured every 2 hours using a rapid moisture analyzer (detection accuracy 0.1%) until the moisture content stabilizes at ≤7%. After equilibration, the quinoa germ tea product that has been matured by programmed temperature and humidity alternation is obtained.

[0207] The technical advantages of this solution are as follows: Programmed temperature and humidity alternation aging, through periodic temperature and humidity control of "heating and humidification - maintaining high temperature and humidity - cooling and dehumidification - maintaining low temperature and humidity," simulates the natural aging process with more precise and controllable parameters. This promotes the slow occurrence of Maillard reactions and caramelization reactions in the flavor precursors (such as sugars and amino acids) within quinoa germ tea, generating a richer and more complex flavor profile. This results in a more intense aroma and a fuller, more mellow taste, avoiding the uneven flavor issues that often occur during natural aging. Simultaneously, the periodic temperature and humidity changes promote a more uniform distribution of moisture within the product. Combined with subsequent balancing treatment, the moisture content is stabilized at ≤7%, reducing the risk of clumping and mold growth during storage due to uneven moisture distribution, thus improving product storage stability. Furthermore, this aging process requires no additional additives; quality is optimized solely through environmental parameter control. It preserves the natural nutrients of quinoa germ while avoiding the introduction of exogenous substances that could affect product purity. The programmed operation allows for precise reproduction, ensuring consistency in flavor and moisture content across different batches, meeting the demands of stable industrial production.

[0208] The technical effects of this technical solution will be illustrated below through specific embodiments and comparative examples.

[0209] <Example 5>

[0210] 1. Pre-processing: Quinoa germ tea primary product was prepared according to the complete steps of Example 4. Quinoa germ was washed, ultrasonically soaked (50W, 40kHz, 12min, soaking solution was 1% sodium ascorbate aqueous solution), drained, steamed with saturated steam at 88℃ for 4min, and then steamed with saturated steam at 98℃ for 6min to obtain mature germ. 10% of the mature germ was mixed with drinking water at a ratio of 1:4, homogenized, and mixed with corn-derived edible grade porous starch (100 mesh) at a ratio of 1:1 and spray-dried to prepare a composite adsorbent. The remaining mature germ was dehydrated at 70℃ for 6min and stir-fried at 250W for 4min to obtain the first stir-fried germ. It was mixed with 2% composite adsorbent, allowed to stand for 15min, and then stir-fried at 400W for 3min to obtain the final stir-fried quinoa germ tea primary product.

[0211] 2. Programmed Temperature and Humidity Cycling Maturation: Select a programmable temperature and humidity chamber (temperature control accuracy ±0.5℃, humidity control accuracy ±2%). Disinfect the inside of the chamber and the food-grade stainless steel breathable trays (2mm pore size) with 75% alcohol beforehand. Take 1000g of quinoa germ tea (initial product) and spread it evenly on three trays (1.5cm thick on each tray, without clumping). Place the trays on the three shelves inside the chamber (15cm spacing between shelves), close the chamber door, and start the program. Execute three 16-hour cycles within 48 hours.

[0212] Heating and humidification phase (4h): The temperature is raised from 25℃ to 40℃ at a constant rate (heating rate 3.75℃ / h), and the relative humidity is raised from 45% to 65% at a constant rate (humidity rate 5% / h).

[0213] High temperature and high humidity maintenance period (4h): Maintain 40℃ and 65% stability;

[0214] Cooling and dehumidification section (4h): The temperature drops uniformly from 40℃ to 28℃ (cooling rate 3℃ / h), and the relative humidity drops uniformly from 65% to 40% (dehumidification rate 6.25% / h).

[0215] Low temperature and low humidity maintenance period (4h): Maintain a stable temperature of 28℃ and 40%.

[0216] 3. Moisture balance: After 3 cycles, the sample was taken out and transferred to a constant temperature and humidity cabinet at 25°C and 35% relative humidity. The moisture content was measured every 2 hours using a rapid moisture analyzer (accuracy 0.1%) until the moisture content stabilized at 6.2% (≤7%), and the finished product of Example 5 was obtained.

[0217] <Comparative Example 6>

[0218] Comparative Example 6 omits the programmed temperature and humidity alternating aging process and only undergoes natural aging. Details are as follows:

[0219] 1. Pre-processing: The "pre-processing" steps are exactly the same as those in Example 5, resulting in the same final roasted quinoa germ tea product.

[0220] 2. Natural Aging Treatment: Without programmed temperature and humidity alternation aging, 1000g of quinoa germ tea was taken and spread evenly on three food-grade stainless steel breathable trays (1.5cm thick). The trays were placed in a naturally ventilated environment at 25℃ and 45% relative humidity (avoiding direct sunlight) for aging. The aging time was the same as the total processing time in Example 5 (48 hours + time to reach moisture balance ≤7%, approximately 52 hours). The samples were turned over every 12 hours. After aging, the moisture content was measured and adjusted to 6.5% (≤7%) through natural ventilation, yielding the finished product of Comparative Example 6.

[0221] <Comparative Example 7>

[0222] Comparative Example 7 used a single temperature and humidity aging process, without alternating cycles, as detailed below:

[0223] 1. Pre-processing: The "pre-processing" steps are exactly the same as those in Example 5, resulting in the same final roasted quinoa germ tea product.

[0224] 2. Single-temperature and humidity aging: Using the same programmable temperature and humidity chamber as in Example 5, 1000g of quinoa germ tea was spread evenly on three trays (1.5cm thick) and placed on the shelf inside the chamber. The chamber parameters were set to 35℃ and 55% relative humidity, and this single temperature and humidity was maintained continuously for 48 hours without periodic temperature and humidity changes. After aging, the tea was transferred to a constant temperature and humidity cabinet at 25℃ and 35% relative humidity to balance the moisture content to 6.3% (≤7%), yielding the finished product of Comparative Example 7.

[0225] <Indicator Detection Methods>

[0226] 1. Total amount of flavor compounds

[0227] The determination was performed according to the aforementioned method for "retention of flavor substances", and the results were expressed as the peak area of ​​total volatile aroma components.

[0228] 2. Peak area percentage of characteristic flavor compounds

[0229] Qualitative and semi-quantitative analyses were performed using gas chromatography-mass spectrometry (GC-MS). Specific conditions were as follows:

[0230] Instrumentation: Gas chromatography-mass spectrometry (GC-MS) system.

[0231] Chromatographic conditions: The chromatographic column and temperature program are the same as those for the determination of "retention of flavor substances" to ensure data comparability.

[0232] Mass spectrometry conditions: ion source temperature 230℃; ionization mode EI, electron energy 70eV; scan range m / z 35-450.

[0233] Analysis and Calculation: Qualitative analysis of the detected volatile flavor compounds was performed by comparing mass spectra with the NIST standard mass spectrometry library. Based on this, the relative peak area percentages of the identified flavor compounds were calculated.

[0234] 3. Uniformity of moisture distribution

[0235] Low-field nuclear magnetic resonance (LF-NMR) was used. 2.00g of sample was weighed and placed in a special sample tube. The transverse relaxation time (T2) distribution of free water and bound water in the sample was detected. The peak area ratio of different water states was calculated. The uniformity of water distribution was evaluated by the peak area variation coefficient (CV) (the smaller the CV, the more uniform the water distribution). The experiment was repeated 3 times and the average value was taken.

[0236] 4. Storage stability (caking rate)

[0237] After sealing the sample, store it in a constant temperature and humidity chamber at 25℃ and 60% relative humidity for 60 days. After taking it out, pass it through a 10-mesh sieve, weigh the mass of the agglomerated sample that did not pass through the sieve, and calculate the agglomeration rate (agglomeration rate = mass of agglomerated sample / total mass of sample × 100%). Repeat 3 times and take the average value.

[0238] <Indicator Detection Results>

[0239] The above-mentioned indicators of quinoa germ tea in Example 5 and Comparative Examples 6-7 were measured, and the results are shown in Table 5.

[0240] Table 5. Measurement results of Example 5 and Comparative Examples 6-7

[0241]

[0242] As shown in Table 5, the peak area of ​​the total volatile aroma components in Example 5 was significantly higher than that in Comparative Examples 6 and 7, and the peak area of ​​characteristic flavor substances accounted for a higher proportion. This is because the "heating and humidification - high temperature and high humidity maintenance" stage of programmed temperature and humidity alternation aging provided suitable conditions for Maillard reaction and caramelization reaction, promoting the generation of more flavor substances. In contrast, the temperature and humidity of Comparative Example 6 fluctuated greatly during natural aging and the parameters were uncontrollable, resulting in insufficient reaction and less generation of flavor substances. Comparative Example 7 lacked dynamic control of temperature and humidity, and the reaction rate was slow, with the types and contents of flavor substances being less than those in Example 5.

[0243] Example 5 exhibited the lowest CV value for moisture distribution, indicating that periodic temperature and humidity changes caused repeated migration and redistribution of moisture within the sample, ultimately achieving a uniform state. Comparative Example 6, with its unstable humidity during natural aging, showed uneven local moisture absorption, resulting in the highest CV value. Comparative Example 7, under a single temperature and humidity environment, showed only unidirectional moisture diffusion, with less uniformity than Example 5. Moisture distribution uniformity directly affects the storage clumping rate. Example 5 showed the lowest clumping rate after 60 days of storage because uniform moisture reduces moisture absorption and adhesion between particles. Comparative Example 6 showed the highest clumping rate due to uneven moisture distribution and localized high-moisture areas. While Comparative Example 7 was superior to Comparative Example 6, its clumping rate was still higher than Example 5 due to insufficient moisture uniformity.

[0244] In summary, the programmed temperature and humidity alternation aging process of the present invention, through precise and controllable periodic temperature and humidity regulation, is superior to natural aging and single temperature and humidity aging in terms of flavor generation, moisture uniformity and storage stability, effectively solving the problems of unstable quality and poor effect of existing aging processes.

[0245] In another technical solution, when preparing the coated porous starch in step S2, soybean lecithin, accounting for 0.1% to 0.5% of the total mass of the coating solution, is also uniformly mixed into the gelatin coating solution.

[0246] In the above technical solution, the preparation of the coating solution is adjusted during the preparation of coated porous starch to achieve uniform mixing of soybean lecithin. Firstly, food-grade soybean lecithin (purity ≥95%, in powder form, purchased from a conventional food additive supplier) is selected. This raw material is commonly used as an emulsifier in food processing, which can improve the dispersion uniformity of the liquid system and has good compatibility with gelatin, without causing precipitation or stratification.

[0247] Next, the coating solution was prepared: Type A food-grade gelatin was selected and added to drinking water. The mixture was placed in a 55°C water bath and stirred continuously at 300 rpm for 20 minutes until the gelatin was completely dissolved, forming a 12% (w / w) gelatin aqueous solution. During this process, the water bath temperature was kept stable to prevent incomplete dissolution due to temperature fluctuations. Then, food-grade soybean lecithin (0.3% of the total mass of the coating solution) was added to the gelatin aqueous solution. The stirring speed was increased to 400 rpm and continued for 25 minutes, while maintaining the solution temperature at 50-55°C. This ensured that the soybean lecithin was fully dispersed in the gelatin aqueous solution, forming a homogeneous coating solution without obvious particles or stratification. After preparation, the coating solution was kept at 50°C for later use to prevent the gelatin from cooling and solidifying, which could cause the soybean lecithin to precipitate.

[0248] The technical effects of this solution are as follows: the addition of soybean lecithin can improve the emulsification and dispersibility of the coating solution, avoiding uneven atomization due to excessive surface tension during the spraying of gelatin aqueous solution, allowing the coating layer to cover the porous starch surface more evenly, reducing the problem of excessive coating thickness or leakage in some areas, and improving the batch consistency of coated porous starch; at the same time, the surface activity of soybean lecithin can enhance the binding force between the coating layer and porous starch particles, reducing the phenomenon of coating layer peeling off during drying or subsequent processing, and ensuring stable flavor control and release effect; in addition, soybean lecithin has good compatibility with the lipid components in quinoa germ, and when the composite adsorbent is mixed with quinoa germ for processing, it can promote the tight binding of the adsorbent and germ particles, further improving the adsorption and control and release capacity of flavor substances, and soybean lecithin itself has no odor and will not have an adverse effect on the taste of the final quinoa germ tea, but can help to release flavor substances evenly during brewing, improving the drinking experience.

[0249] In another technical solution, after the programmed temperature and humidity alternating ripening step, a fluidized bed low-temperature steady-state treatment step is further included, as follows: the ripened quinoa germ tea is placed in a fluidized bed, and dehumidified air with a dew point of -10°C to -15°C is used as the fluidizing medium at a temperature of 65~75°C for 15~25 minutes.

[0250] In the above technical solution, after completing the programmed temperature and humidity alternating ripening steps, the obtained quinoa germ tea undergoes fluidized bed low-temperature steady-state treatment. First, an intermittent fluidized bed (equipped with hot air heating and dehumidified air supply functions, purchased from a conventional food processing equipment supplier) is selected. This equipment needs to be cleaned and disinfected in advance—the fluidized bed cavity, material tray, and airflow pipes are wiped with 75% alcohol and then dried before use. The dehumidified air inlet of the fluidized bed is installed at the bottom of the equipment, with a dehumidifier unit (capable of controlling the air dew point between -10℃ and -15℃) and a 5μm precision air filter connected sequentially at the front end to ensure that the dehumidified air entering the fluidized bed is clean and has stable humidity. The temperature control system probe is embedded in the side wall of the fluidized bed cavity to monitor the cavity temperature in real time, with a temperature control accuracy of ±1℃. The material tray is made of food-grade stainless steel (2mm aperture) and placed in the middle of the fluidized bed to ensure full contact with the airflow.

[0251] Sample processing followed: 1000g of quinoa germ tea, matured under programmed temperature and humidity alternation, was evenly spread in a food-grade stainless steel material tray, with a thickness controlled at 1.2cm to avoid sample accumulation and uneven airflow penetration. The tray was placed in the fluidized bed, the equipment door was closed, and the dehumidifier and fluidized bed heating system were started. The dehumidified air dew point was adjusted to -12℃, introduced into the fluidized bed, and heated to 70℃. At the same time, the airflow rate was adjusted to 1.3m / s, so that the quinoa germ tea was in a slightly fluidized state in the fluidized bed (confirmed through the equipment observation window that there was no obvious agglomeration or adhesion of particles to the wall).

[0252] The above conditions (temperature 70℃, dehumidified air dew point -12℃, airflow rate 1.3m / s) were maintained for 20 minutes. During the treatment, a small sample was taken every 5 minutes through the sampling port of the equipment, and the moisture content was detected using a rapid moisture analyzer (detection accuracy 0.1%) to observe the moisture change trend. After the treatment, the heating system was turned off, and room temperature dehumidified air (dew point -12℃) was continuously circulated for cooling for 5 minutes. After the sample temperature dropped below 30℃, the fluidized bed door was opened and the material tray was removed to obtain the quinoa germ tea product that had undergone low-temperature steady-state treatment.

[0253] The technical advantages of this solution are as follows: The fluidized bed low-temperature steady-state treatment uses dehumidified air with a dew point of -10℃ to -15℃ as the fluidizing medium. This efficiently removes trace amounts of free water remaining in samples after programmed temperature and humidity alternation ripening at a lower temperature of 65-75℃, preventing the destruction of nutrients or loss of flavor compounds due to high temperatures. Simultaneously, it further stabilizes the product's moisture content at 6%-7%, with more uniform moisture distribution. The slight fluidization state ensures that each quinoa germ tea particle is fully in contact with the dehumidified air, preventing localized moisture residue and reducing the risk of clumping and mold growth during storage. Furthermore, the low-temperature steady-state treatment further fixes the product's physical structure, resulting in more consistent crispness of the quinoa germ tea particles, making them less prone to crumbling during brewing. It also helps retain flavor compounds generated during ripening, extending the product's shelf life and flavor stability, thus meeting the requirements for product quality uniformity and storability in industrial production.

[0254] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A method for processing quinoa germ tea, characterized by, The method comprises the following steps: S1, the washed, soaked and drained quinoa germ is first steamed in saturated steam at 85-90℃ for 3-5 min, and then steamed in saturated steam at 95-100℃ for 5-8 min to obtain matured quinoa germ; S2, take 5%-15% of the total weight of the matured quinoa germ, mix it with drinking water at a mass ratio of 1:3-5, beat it, homogenize it, then mix it with edible porous starch at a mass ratio of 1:0.5-2, and spray dry it to obtain a quinoa germ composite adsorbent; S3, the remaining matured quinoa germ in S1 is treated at 65-75℃ for 5-8 min to obtain dehydrated quinoa germ; the dehydrated quinoa germ is stirred at 200-300W for 3-5 min to obtain primary roasted quinoa germ; S4, the primary roasted quinoa germ is mixed with 1%-3% of the quinoa germ composite adsorbent by weight, and is evenly mixed and placed in a sealed container for 10-20 min to obtain aging material, and the aging material is roasted at 300-450W for 2-4 min to obtain the quinoa germ tea; In step S1, the washed, soaked and drained quinoa germ is obtained by the following method: the washed quinoa germ is placed in a soaking solution, and ultrasonic treatment is carried out at a power of 50-100W and a frequency of 40kHz for 8-15 min, the soaking solution is an aqueous solution containing 0.5%-1.5% sodium ascorbate by mass, the volume-to-mass ratio of the soaking solution to the quinoa germ is 3-5 mL / g, and the soaking treatment is followed by draining; After the final roasting in S4, a programmed temperature and humidity alternating aging step is further included, which is as follows: The quinoa germ tea is placed in a programmable constant temperature and humidity box, and within 48 hours, three consecutive temperature and humidity cycle programs are executed by the control system, each cycle being 16 hours, wherein: a) temperature and humidity rising segment: the temperature in the box is uniformly raised from 25℃ to 40℃ within 4 hours, and the relative humidity is uniformly raised from 45% to 65% at the same time; b) high temperature and high humidity maintenance segment: maintained at 40℃ and 65% relative humidity for 4 hours; c) temperature and humidity falling segment: the temperature in the box is uniformly lowered from 40℃ to 28℃ within 4 hours, and the relative humidity is uniformly lowered from 65% to 40% at the same time; d) low temperature and low humidity maintenance segment: maintained at 28℃ and 40% relative humidity for 4 hours; After completing three complete cycle programs, the product is balanced to a moisture content of ≤7% at 25℃ and a relative humidity of 35%.

2. The quinoa germ tea processing method according to claim 1, characterized in that, Before the static placement of the mixed material in step S4, a cold air solidification treatment is first carried out, which is as follows: the mixed material is placed in a low-temperature air flow at 2-10℃ for 1-3 min.

3. The method of processing quinoa germ tea according to claim 2, wherein, After the final roasting of S4, the aged material is immediately transferred into a closed container filled with a protective atmosphere, and the material temperature is slowly reduced from the end-point roasting temperature to 35-45℃ at a rate not higher than 5℃ / min, and the protective atmosphere is maintained during the temperature reduction process until the material temperature reaches 35-45℃, and then the material is packed.

4. The quinoa germ tea processing method according to claim 2, characterized in that, In the S2 step, the food-grade porous starch is pretreated with a flavor-controlled release coating before being used to prepare the composite adsorbent, specifically as follows: The food-grade porous starch is placed in a fluidized bed, and hot air at 40-50℃ is introduced, and then a coating liquid is uniformly sprayed onto the surface of the porous starch, the coating liquid being an aqueous solution of food-grade gelatin with a mass concentration of 8-15%, and after the spraying is completed, the fluidized drying is continued at 55-65℃ for 20-40 min to obtain the pretreated coated porous starch, which is then used to prepare the quinoa germ composite adsorbent.

5. The method of processing quinoa germ tea according to claim 4, wherein the quinoa is selected from the group consisting of white quinoa, red quinoa, black quinoa, and mixtures thereof. In the preparation of the coated porous starch in the S2 step, 0.05-0.2% of tea polyphenol by mass of the total coating liquid is uniformly mixed into the gelatin coating liquid.

6. The quinoa germ tea processing method according to claim 4, characterized in that, In the preparation of the coated porous starch in the S2 step, 0.1-0.5% of soybean phospholipid by mass of the total coating liquid is uniformly mixed into the gelatin coating liquid.

7. The method of processing quinoa germ tea according to claim 1, wherein the quinoa is selected from the group consisting of white quinoa, red quinoa, black quinoa, and mixtures thereof. After the programmed temperature and humidity alternating curing step, a step of fluidized bed low-temperature steady-state treatment is further included, specifically as follows: the cured quinoa germ tea is placed in a fluidized bed, and dehumidified air with a dew point of -10 to -15℃ is used as the fluidizing medium at a temperature of 65-75℃ for 15-25 min.

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