Method for preparing crafted beer rich in characteristic flavone components from cyperus esculentus bean pulp

Abstract

The invention belongs to the technical field of beer brewing, and particularly relates to a method for preparing crafted beer rich in characteristic flavone components from cyperus esculentus bean pulp. According to the method disclosed by the invention, the content of total flavonoids and the content of dihydroflavonoids and dihydroflavonols are mainly taken as indexes, the flavor of the craft beer under different addition amounts of the cyperus esculentus bean pulp is investigated, and the optimal addition amount of the cyperus esculentus bean pulp is screened out in combination with sensory evaluation. The method has the beneficial effects that the optimal dosage of the cyperus esculentus bean pulp in the craft beer is obtained, so that the brewed beer not only has high flavonoid content, especially is rich in flavonoid and flavonol, but also is pure in taste, obvious in bouquet, soft in taste and fresh and cool in overall taste.

Description

Technical Field

[0001] The invention belongs to the technical field of beer brewing, and particularly relates to a method for preparing craft beer rich in characteristic flavonoid components by utilizing cyperus oleifera bean meal. Background Art

[0002] Because cyperus rotundus meal has characteristic functional ingredients such as flavonoids, the craft beer made from cyperus rotundus meal not only improves the single taste of beer, but also is favored by consumers because of its functional ingredients such as flavonoids. However, there is currently a lack of methods for evaluating the sensory and functional characteristics of cyperus rotundus meal beer, making it difficult to accurately determine the quality grade of beer. In addition, the resources of cyperus rotundus meal are relatively limited in China, and the cost is higher than that of ordinary beans. It is possible that other low-value bean raw materials will be used to replace or counterfeit cyperus rotundus meal craft beer. In addition, when the amount of cyperus rotundus meal is too small, the flavonoids in it will be correspondingly less, which may easily lead to insufficient characteristic flavor of the craft beer produced in the end; and if the amount of cyperus rotundus meal is too large, it is easy to cause oil substances to float on the surface of the wort, causing the wort to be unable to be clear and transparent during filtration, affecting the fermentation effect and quality of the beer, and the cost is also correspondingly high. Regarding the relationship between the amount of cyperus oleifera meal and the flavor of cyperus oleifera meal craft beer, there is currently no effective method to determine the correlation between the flavor quality and the amount of cyperus oleifera meal used in its preparation process. This technical problem needs to be solved urgently.

[0003] Given that the higher the amount of cyperus tannica meal used, the higher the functional components in cyperus tannica meal beer and the better the flavor, the taste, flavor and quality of cyperus tannica meal beer are closely related to the amount of cyperus tannica meal used, but the relationship is not proportional. Therefore, the amount of cyperus tannica meal used will significantly affect the flavor of beer, and how to control its amount during beer processing is also a technical problem that needs to be solved.

[0004] A patent document has disclosed a process for preparing craft beer made from cyperus oleifera meal. In this process, cyperus oleifera meal is extracted and then mixed with beer fermentation liquid to obtain cyperus oleifera meal craft beer. Similarly, the document does not explore the relationship between the amount of cyperus oleifera meal used and the flavor, taste and quality of beer.

[0005] Therefore, it is necessary to invent a method that can quickly monitor the correlation between flavor quality and the amount of cyperus rotundus meal in the preparation process of craft beer brewed with cyperus rotundus meal, and through the exploration of this method, obtain the amount of cyperus rotundus meal used in beer brewing, so that the prepared beer not only has the best flavor, but also has a high flavonoid content and excellent quality. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a method for forming a fingerprint database based on GC-IMS analysis and flavonoids analysis. On the basis of the database, data is analyzed and processed to determine the correlation between the flavor quality of Cyperus juncea bean meal craft beer and the amount of Cyperus juncea bean meal used. On this basis, the most appropriate amount of Cyperus juncea bean meal is used to prepare high-quality Cyperus juncea bean meal craft beer.

[0007] The method for preparing craft beer rich in characteristic flavonoid components by using cyperus oleifera soybean meal comprises the following steps:

[0008] (1) taking defatted cyperus oleifera meal, adding the cyperus oleifera meal to malt, mixing, grinding and saccharifying to obtain wort in the saccharification stage of craft beer processing, and obtaining craft beer prepared with cyperus oleifera meal as raw material through saccharification and fermentation;

[0009] The amount of soybean meal added is set to 10-40% based on the sum of the weight of soybean meal and malt; N different concentration values ​​are randomly selected from 10-40% as the amount of cyperus juncea meal (soybean meal) added, and the craft beers obtained under different amounts of cyperus juncea meal added are recorded as sample 1, sample 2, sample 3, ..., sample N, respectively;

[0010] (2) Taking flavonoids as the investigation index:

[0011] Take sample 1, sample 2, sample 3, ..., sample N in (1), and test the total flavonoids of the above samples respectively. Use the total flavonoid content as a preliminary screening index to screen out the group with high total flavonoid content; then further screen out the group with high content of dihydroflavonoids and dihydroflavonols, and record it as retained sample 1;

[0012] (3) Sensory evaluation: Sample 1, sample 2, sample 3, sample 4, ... sample N are subjected to sensory evaluation and scoring, and the sample with the highest score is recorded as retained sample 2;

[0013] Quality inspection: Determine the original wort concentration, alcohol concentration, and diacetyl content of the above-mentioned samples 1, 2, 3, 4, ..., N, and take the sample with high original wort concentration, high alcohol concentration, and low diacetyl as the sample with good quality, and record it as the reserved sample 3;

[0014] Combined with the preliminary screening samples 1, 2, and 3, we screened out craft beer samples that were rich in characteristic flavonoid components, had high sensory evaluation scores, and had good quality, thereby determining the optimal amount of cyperus oleifera meal to be added.

[0015] The method further comprises (4): preparing craft beer according to the step (1) based on the optimized amount of Cyperus juncea meal added in (3) to obtain craft beer rich in characteristic flavonoid components using Cyperus juncea meal. The craft beer can be brewed using conventional processes, which differ from conventional beer brewing processes in that Cyperus juncea meal is added at the same time as malt, and the amount of addition is determined and optimized according to the above steps.

[0016] Preferably, in (1), the defatted and dried cyperus juncea meal is mixed with malt, crushed, and then added to water at 48-52° C., with a material-water ratio of 1:3-5, and stirred continuously during the addition; the amount of cyperus juncea meal used when the wort yield is 65-70% is recorded, and the amount of cyperus juncea meal used is determined to be 10-40%.

[0017] Through the above steps (1) to (3), the optimal addition amount of cyperus oleifera meal in the craft beer sample finally determined is 20%. Under this addition ratio, the obtained craft beer has a high content of flavor substances and the best taste.

[0018] The beneficial effects of the present invention are:

[0019] (1) Through the method of the present invention, the relationship between the amount of cyperus chinensis meal added and the flavor quality of cyperus chinensis meal beer is obtained, which breaks through the situation that there is no effective method to determine the correlation between the flavor quality and the amount of cyperus chinensis meal used in the preparation process of cyperus chinensis meal beer;

[0020] (2) The method of the present invention can obtain the optimal dosage of Cyperus oleifera meal in craft beer, so that the brewed beer not only has a high flavonoid content, especially rich in flavanols and dihydroflavonols, but also has a high sensory score. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a graph showing the change of wort yield in Example 1;

[0022] Figure 2 Sensory evaluation of craft beer with different addition amounts of Cyperus oleifera meal;

[0023] Figure 3 The original wort concentration in craft beer at different addition ratios of Cyperus oleifera meal;

[0024] Figure 4 The alcohol concentration in craft beer at different addition ratios of Cyperus oleifera meal;

[0025] Figure 5 The diacetyl content in craft beer at different addition ratios of Cyperus oleifera meal;

[0026] Figure 6This is the saccharification curve diagram in Example 1. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in conjunction with specific implementation methods.

[0028] Example 1

[0029] (I) Determination of the amount of cyperus rotundus soybean meal used in craft beer

[0030] (1) Defatted soybean meal of Cyperus oleifera was taken and added to malt for mixing, grinding and saccharification to obtain wort in the saccharification stage of craft beer processing. The temperature of the feed was 50°C and the feed-water ratio was 1:4. After saccharification (100 minutes), the saccharification curve was as shown in the attached figure. Figure 6 As shown), fermentation, to obtain craft beer prepared with Cyperus oleifera meal as raw material;

[0031] When determining the dosage of cyperus rotundus meal, the dosage of cyperus rotundus meal is initially set to 10%, 20%, 30%, and 40% based on the sum of the weight of soybean meal and malt. The inventor found in a preliminary experiment on the dosage of 40% that when the dosage of cyperus rotundus meal is 40%, the oil substance will float on the surface of the wort, and this phenomenon causes the wort to be unable to present a clear and transparent state when filtering. The presence of oil not only affects the appearance quality of the wort, but may also have an adverse effect on the subsequent fermentation and beer taste. Therefore, the dosage of cyperus rotundus meal is set to 10%, 20%, and 30%. The craft beer prepared under the above-mentioned cyperus rotundus meal dosage is recorded as: sample 1, sample 2, and sample 3, and the content of flavonoids, sensory evaluation, and quality quality inspection are respectively carried out on samples 1-3.

[0032] During the saccharification process, the wort yield was used as an indicator to determine the appropriate amount of cyperus oleifera meal to be added. Figure 1 As shown in the figure, the wort yield first increased and then decreased. When the addition amount was 20%, the wort yield was the highest. As the addition amount of cyperus oleifera meal increased, the wort yield also decreased. It may be that cyperus oleifera meal contains rich starch and protein, but no proteolytic enzymes and amylolytic enzymes. Therefore, a small amount of addition can increase the wort yield. As the addition ratio of cyperus oleifera meal increases, the enzyme content shows a trend of gradual decrease, the saccharification process is not sufficient, the extract content decreases, and the wort yield decreases.

[0033] Although wort yield is one of the evaluation indicators, it is also necessary to investigate the content of flavonoid flavor substances under different addition amounts of cyperus oleifera meal, so the following experiments are continued:

[0034] (2) Take sample 1, sample 2, and sample 3 in (1), and test the total flavonoids contained in them respectively. Take the total flavonoid content as the preliminary screening index, select the group with high total flavonoid content to further test the content of dihydroflavonoids and dihydroflavonols, and keep the group with high content of dihydroflavonoids and dihydroflavonols as sample 1;

[0035] (3) Sensory evaluation: Sample 1, Sample 2, and Sample 3 were subjected to sensory evaluation. The specific scoring criteria and scores of the sensory evaluation are shown in Example 3. The sample with the highest score was recorded as the retained sample 2.

[0036] At the same time, the quality of samples 1, 2, and 3 was examined, specifically the sample with high original wort concentration, high alcohol concentration, and low diacetyl was selected as the sample with good quality and was retained as sample 3;

[0037] (4) Based on the flavonoid index, sensory evaluation and quality index investigation in (2)-(3), the retained samples 1, 2 and 3 were comprehensively verified. The results showed that when the content of cyperus juncea meal was 20%, the craft beer prepared was rich in characteristic flavonoids, had the highest sensory score and excellent quality (relatively high original wort concentration, high alcohol concentration and low diacetyl). Therefore, the dosage of cyperus juncea meal was determined to be 20%.

[0038] Example 2

[0039] Preparation technology of craft beer brewed from cyperus oleifera meal:

[0040] (1) Malt grinding: First, light-colored malt and degreased cyperus oleifera meal (dried, with a moisture content of about 2%) are selected, respectively ground with a grinder and a roller mill, and mixed evenly to form a mixed raw material;

[0041] (2) Wort saccharification: preheat hot water at 50°C (measured in real time with a thermometer) for later use, add hot water to the mixed raw materials (Cyperus juncea meal + malt mixed powder, in which Cyperus juncea meal accounts for 20% of the mixed raw materials and the remainder is malt) at a volume ratio of 1:4, and pour into the saccharification barrel, stirring continuously for about 30 minutes; then, raise the temperature to 62°C at a rate of 1°C / min and maintain for 90 minutes; continue to raise the temperature to 72°C and maintain for 10 minutes; and maintain at 78±0.5°C for 10 minutes.

[0042] (3) Wort filtration: After the saccharification stage, the wort was filtered with a filter cloth; the wort concentration was measured with a handheld sugar meter. After testing, the wort recovery rate was 71.2%;

[0043] The calculation formula of wort yield is as follows:

[0044]

[0045] (4) Boiling wort: heat and boil for 70 minutes, add granular hops three times, add the first bitter hops when the wort boils for 10 minutes; keep boiling for 20 minutes, add the second bitter hops; keep boiling for 30 minutes, add the third aroma hops, filter immediately after boiling, and cool to room temperature;

[0046] (5) Cycloid precipitation: After boiling, filter with filter cloth;

[0047] (6) Cooling the filtered material in (5) to below 10° C. to obtain mixed cyperus rotundus meal wort; pumping the mixed cyperus rotundus meal wort into a fermentation tank, adding brewer's yeast for low-temperature fermentation; when the sugar content of the wort drops to 4.5° P, lowering the temperature to below 0° C., continuing fermentation for 7 days, obtaining original fermented beer, and obtaining finished craft beer through subsequent conventional treatment methods such as filtering brewer's yeast.

[0048] Example 3

[0049] In step (2) of Example 1, the flavonoid content including the total flavonoid content and the representative different flavonoid content is used as a very important investigation index, and its content in the cyperus rotundus soybean meal craft beer is detected, and the data is analyzed and processed to determine the correlation between the total flavonoid content, characteristic composition and the amount of cyperus rotundus soybean meal used in the craft beer. This is because the flavor of the cyperus rotundus soybean meal craft beer has a certain correlation with the content of flavonoids in the cyperus rotundus soybean meal, but because the specific amount of cyperus rotundus soybean meal cannot be controlled, therefore, there is no investigation method for the correlation between the flavor of the cyperus rotundus soybean meal craft beer and the amount of cyperus rotundus soybean meal (soybean meal). This is also a bottleneck restricting the development of cyperus rotundus soybean meal craft beer.

[0050] In view of the above problems, the three mass ratios of 0% (blank control), 10%, 20%, and 30% of the addition ratio of cyperus oleiferus meal (soybean meal) were selected as variables in this application. Combined with the method for screening the dosage of cyperus oleiferus meal in Example 1 and the method for craft beer in Example 2, a total of 11 tannic acid and 390 flavonoid metabolites were detected based on the UPLC-MS / MS detection platform and the self-built database. The detected flavonoids were further classified into 10 categories, including flavonols, flavones, dihydroflavones, dihydroisoflavones, isoflavones, anthocyanins, aurones, chalcones, flavanols, and other flavonoids.

[0051] The specific methods for detecting and analyzing flavonoid content are as follows:

[0052] ① The sample is thoroughly mixed for 30 seconds using a vortexer, 9 ml of the sample is accurately measured, and freeze-dried under vacuum conditions. After drying, 900 μl of 70% methanol internal standard extract is added to the sample. Vortex the mixture again for 15 minutes using a vortexer. Then place the mixture in an ice water bath and perform ultrasonic treatment for 10 minutes. After the ultrasonic treatment, the mixture is centrifuged at 12,000 rpm at 4°C for 3 minutes. After centrifugation, take the supernatant and filter it using a 0.22 μm microporous filter membrane. Finally, store the filtered supernatant in a dedicated injection bottle.

[0053] ② Set liquid phase conditions: chromatographic column is Agilent SB-C18 1.8μm, 2.1mm*100mm; mobile phase A is ultrapure water (with 0.1% formic acid added), and mobile phase B is acetonitrile (with 0.1% formic acid added); elution gradient: 0.00min B phase ratio is 5%, within 9.00min, the B phase ratio linearly increases to 95%, and maintains at 95% for 1min, 10.00-11.10min, the B phase ratio is reduced to 5%, and balanced at 5% for 14min; flow rate is 0.35mL / min; column temperature is 40℃; injection volume is 2μL.

[0054] ③Setting mass spectrometry conditions: During the operation of the electrospray ion source (ESI), the temperature condition was set to 550°C. The ion spray voltage (IS) was set to 5500V in positive ion mode and -4500V in negative ion mode. The flow rate of gas I (GSI) was set to 50psi, the flow rate of gas II (GSII) was set to 60psi, and the flow rate of curtain gas (CUR) was set to 25psi. The collision-induced ionization parameter was set to a high level. During mass analysis, the QQQ scanning mode used multiple reaction monitoring (MRM) technology, and the collision gas (nitrogen) was set to a medium flow rate. The declustering potential (DP) and collision energy (CE) were optimized to complete the parameter setting for each MRM ion pair. According to the characteristics of the metabolites in different elution stages, a specific set of MRM ion pairs was monitored in each period.

[0055] ④ Data processing in step 5: Based on the self-built MWDB (Metware database), qualitative analysis of substances is performed based on secondary mass spectrometry information. In the quantitative analysis of metabolites, the MRM mode of the triple quadrupole mass spectrometer is used for precise analysis. The mass spectrometry data of the samples is processed using MultiQuant software to integrate and correct the chromatographic peaks.

[0056] The contents of flavonoid metabolites in beer were compared and analyzed, and the results are shown in Table 1. There were differences in the contents of flavonoid metabolites in beer with different addition amounts of Cyperus oleifera meal, and the total flavonoid content in beer first increased and then decreased, reaching the highest level at 20%.

[0057] Table 1 Detection results of flavonoids in beer obtained at different addition amounts of Cyperus oleifera meal (mg / 100g)

[0058]

[0059] Comparative analysis of the content of flavonoid metabolites in beer shows that, as shown in Table 1, there are differences in the content of flavonoid metabolites in beer for groups with 0%, 10%, and 30% addition of cyperus oleifera meal. When the addition amount is 20%, the content of total flavonoids is the highest, followed by 10%. At the same time, when the addition amount of cyperus oleifera meal is 20%, the content of dihydroflavonoids and dihydroflavonols is also the highest, and the content distribution of other types of flavonoids is also relatively rich.

[0060] More detailed data on the flavonoid detection in Table 1 are shown in Table 2:

[0061] Table 2 More detailed flavonoid detection results in beer obtained at different dosages of Cyperus oleifera meal

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] (2) Sensory evaluation analysis:

[0074] A sensory evaluation team consisting of 20 professional personnel was selected to give comprehensive scores to the appearance, foam performance, beer aroma, and body and taste of craft beer according to the table below.

[0075] The sensory evaluation results are processed differentially. Figure 2 And as shown in Table 3.

[0076] Table 3 Sensory evaluation score table

[0077]

[0078]

[0079] Table 4 Sensory evaluation scores of beer obtained at different dosages of Cyperus oleifera meal

[0080] 0％ 10％ 20％ 30％ Appearance evaluation 9.13 8.33 9.13 8.33 Foam performance 17.33 16.25 15.13 14.78 Beer aroma 14.13 15.25 18.67 18.00 Wine taste 37.67 34.33 37.78 38.25 Total score 78.26 74.16 80.71 79.36

[0081] From the results, we can see that the appearance evaluation scores are similar, indicating that cyperus chinensis meal does not have much effect on the appearance of beer. The beer without addition has the best foam performance, which may be because the oil content of cyperus chinensis meal is higher than that of malt, which affects the duration and state of the foam. The aroma of beer is the highest with a 20% addition, and the body taste is the best with a 30% addition, which may be because the addition of cyperus chinensis meal brings a richer and fuller taste to the beer. The overall evaluation shows that the sensory score of the beer with a 20% addition is the highest.

[0082] In Example 3, taking into account the content of flavonoids and the scores of sensory evaluation, 20% of the addition amount of Cyperus juncea meal was selected as the optimized addition amount of Cyperus juncea meal craft beer. At this addition amount, the flavor and taste were optimal.

[0083] Example 4

[0084] The effect of different dosages of cyperus oleifera meal on the quality of craft beer was investigated mainly based on three indicators: original wort concentration, alcohol concentration and diacetyl content.

[0085] (1) Original wort concentration

[0086] The original wort concentration is a measure of the content of soluble substances in beer, which mainly reflects the sugar content of the raw wort before fermentation and is a hard reference indicator for beer identification. Figure 3 .Depend on Figure 3It can be seen that the original wort concentration without adding cyperus oleifera meal is generally higher than that with adding cyperus oleifera meal. When the addition ratio is 0%, the original wort concentration is the highest at 12.40°P. In the beer with cyperus oleifera meal, the original wort concentration is the highest at 12.17°P when the addition ratio is 20%. This data is equivalent to the original wort concentration when the addition ratio is 0%, which means that after adding 20% ​​cyperus oleifera meal, the concentration is closer to the original wort concentration, which means that the quality of craft beer at this addition amount is very little affected by cyperus oleifera meal.

[0087] (2) Alcohol concentration

[0088] Effect of the addition ratio of cyperus oleifera meal on alcohol concentration Figure 4 .Depend on Figure 4 It can be seen that the alcohol content of craft beer is greater than 4.5% vol, which meets the physical and chemical requirements of GB / T4927-2008 for pale beer with an original wort concentration of 12.1-14.0 ゜P. The alcohol content of craft beer with 20% cyperus juncea meal added is 7.6% vol, which is higher than that of craft beer without cyperus juncea meal. It is possible that the yeast fermentation process is more complete, resulting in more alcohol. This shows that the addition of cyperus juncea meal is conducive to the fermentation of beer yeast.

[0089] (3) Diacetyl content

[0090] Diacetyl has an unpleasant smell of rotten rice and is produced in the late fermentation process. It is one of the important signs to judge whether the beer is mature. Figure 5 As shown in the figure, with the increase of the addition ratio, the diacetyl content first increased and then decreased. The diacetyl content at 20% addition was as low as 0.02 mg / L. The reason may be that some substances in the cyperus oleifera meal accelerated the reduction of diacetyl. At this addition level, this unpleasant substance was the lowest. But in general, it was less than 0.1 mg / L, which met the physical and chemical requirements of GB / T4927-2008 for light beer.

[0091] As can be seen from the above embodiments, when the flavonoid index is investigated, when the amount of cyperus rotundus meal added is 20%, the content of flavonoids in the craft beer prepared is the most abundant; when the sensory evaluation of the craft beer samples is conducted to investigate the indicators such as body appearance, foam performance, beer aroma, body taste, etc., the sample with 20% cyperus rotundus meal addition has the highest score; when combined with the quality of the craft beer, the results show that when the amount of cyperus rotundus meal is 20%, the test results show that the sample is the closest to the original wort concentration, and the alcohol content is relatively high and the diacetyl content is the lowest. Comprehensively considered, when the amount of cyperus rotundus meal is 20%, the craft beer prepared is rich in characteristic flavonoid components, and the flavor, taste and quality are relatively the best.

Claims

1. A method for preparing craft beer rich in characteristic flavonoid components using cyperus oleifera meal, comprising the following steps: (1) taking defatted soybean meal from cyperus oleifera meal, adding the soybean meal to malt, mixing, grinding and saccharifying to obtain wort in the saccharification stage of craft beer processing, and obtaining craft beer prepared with cyperus oleifera meal as raw material through saccharification and fermentation; The addition amount of cyperus oleifera meal is set to 10-40% based on the sum of the weight of cyperus oleifera meal and malt; N different concentration values ​​are randomly selected from 10-40% as the addition amount of cyperus oleifera meal, and the craft beers obtained under different addition amounts of cyperus oleifera meal are recorded as sample 1, sample 2, sample 3, ..., sample N, respectively; (2) Using flavonoids as an evaluation indicator: Take sample 1, sample 2, sample 3, ... sample N in (1), test the total flavonoids of the above samples respectively, use the total flavonoid content as the preliminary screening index, and screen out the group with high total flavonoid content; then further screen out the group with high content of dihydroflavonoids and dihydroflavonols, and record it as retained sample 1; (3) Sensory evaluation: Conduct sensory evaluation and score Sample 1, Sample 2, Sample 3, Sample 4, ... Sample N. The one with the highest score is recorded as the retained Sample 2; Quality inspection: Determine the original wort concentration, alcohol concentration, and diacetyl content of the above-mentioned samples 1, 2, 3, 4, ..., and N. The sample with high original wort concentration, high alcohol concentration, and low diacetyl is regarded as a sample with good quality and recorded as reserved sample 3; Combined with the preliminary screening samples 1, 2, and 3, we screened out craft beer samples that were rich in characteristic flavonoid components, had high sensory evaluation scores, and had good quality, thereby determining the optimal amount of cyperus oleifera meal to be added.

2. The method for preparing craft beer rich in characteristic flavonoid components using cyperus oleifera soybean meal according to claim 1, characterized in that: The method further includes (4): preparing craft beer according to the step (1) based on the optimized addition amount of Cyperus oleifera soybean meal obtained in (3), thereby obtaining craft beer rich in characteristic flavonoid components using Cyperus oleifera soybean meal.

3. The method for preparing craft beer rich in characteristic flavonoid components using cyperus oleifera meal according to claim 1, characterized in that: (1) The defatted and dried cyperus oleifera meal is mixed with malt, crushed, and then added to water at 48-52°C, with the material-water ratio controlled at 1:3-5, and stirred continuously while adding the materials; the amount of cyperus oleifera meal is determined to be 10-40%.

4. The method for preparing craft beer rich in characteristic flavonoid components using cyperus oleifera meal according to claim 1, characterized in that: (2) At least 1 to 3 samples were selected from the group with high total flavonoid content.

5. The method for preparing craft beer rich in characteristic flavonoid components using cyperus oleifera meal according to claim 1, characterized in that: (2) The method for detecting flavonoids is as follows: ① Take craft beer samples with different amounts of cyperus oleifera meal added, mix them thoroughly for 30 seconds using a vortexer, accurately measure 9 mL of the sample, and freeze-dry under vacuum conditions; then add 900 μL of 70% methanol internal standard extract to the sample, and vortex the mixture again for 15 minutes using a vortexer; then place the mixture in an ice water bath and perform ultrasonic treatment for 10 minutes; after the ultrasonic treatment, centrifuge the mixture at 12,000 rpm at 4°C for 3 minutes; after the centrifugation, take the supernatant and filter it using a 0.22 μm microporous filter membrane; finally, store the filtered supernatant in a dedicated injection bottle; ② Set the liquid phase conditions: the chromatographic column is Agilent SB-C18 1.8 µm, 2.1 mm×100 mm; the mobile phase A is ultrapure water, in which 0.1% formic acid is added; the mobile phase B is acetonitrile, in which 0.1% formic acid is added; the elution gradient is: 0.00 min B phase ratio is 5%, within 9.00 min, the B phase ratio increases linearly to 95% and maintains at 95% for 1 min, 10.00-11.10 min, the B phase ratio is reduced to 5%, and balanced at 5% for 14 min; flow rate 0.35 mL / min; column temperature 40°C; injection volume 2 μL; ③ Setting mass spectrometry conditions: During the operation of the electrospray ion source, the temperature was set to 550°C, the ion spray voltage was set to 5500 V in positive ion mode, and the voltage was adjusted to -4500 V in negative ion mode; the gas I flow rate was set to 50 psi, the gas II flow rate was set to 60 psi, and the curtain gas flow rate was set to 25 psi; the collision-induced ionization parameter was set to a high level, and during the mass analysis process, the QQQ scan mode used multiple reaction monitoring technology, and the collision gas nitrogen was set to a medium flow rate; the declustering voltage and collision energy were optimized, and the parameter settings for each MRM ion pair were completed. According to the characteristics of the metabolites in different elution stages, a specific set of MRM ion pairs in each period were monitored.

6. The method for preparing craft beer rich in characteristic flavonoid components using cyperus oleifera meal as claimed in claim 2, characterized in that: In the craft beer samples, the addition amount of Cyperus oleifera soybean meal was selected as: 20%.

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