Method for judging processing end point of fried rice sprouts and fried rice sprout processing technology

Abstract

The invention provides a method for judging a processing end point of fried rice sprouts and a processing technology of the fried rice sprouts, and the method for judging the processing end point of the fried rice sprouts comprises the following steps: (1) mixing the fried rice sprouts with different frying time and an alcoholic solution, and carrying out ultrasonic extraction to obtain a series of test solution; (2) carrying out liquid chromatography detection on the series of test solutions, calculating peak area ratios of 4-coumaric acid to 5-hydroxymethylfurfural in the fried rice sprouts at different stir-frying times according to detection results, and taking a time period corresponding to a stable peak area ratio range between ratio mutation points as stir-frying time required for reaching a processing end point, and judging the processing end point of the fried rice sprouts. The method provided by the invention can objectively, accurately and clearly judge the processing end point of the fried rice sprouts, fills the blank of judgment of the processing end point of the fried rice sprouts, makes up for the situation of misjudgment caused by evaluation of the processing end point only by colors, realizes monitoring of the processing process of the fried rice sprouts, and can effectively guide the processing technology of the fried rice sprouts.

Description

Technical Field

[0001] The invention belongs to the technical field of traditional Chinese medicine analysis, and particularly relates to a method for judging an end point of stir-fried barley sprout processing and a stir-fried barley sprout processing process. Background Art

[0002] Barley sprouts are obtained by germinating and drying the mature fruits of the grass plant Setaria italica (L.) Beauv. The 2020 edition of the "Chinese Pharmacopoeia (Part I)" includes three commonly used processed products, namely raw barley sprouts, fried barley sprouts and scorched barley sprouts. Different processed products have slightly different effects. Raw barley sprouts have the effects of harmonizing the stomach and promoting digestion, strengthening the spleen and appetizing, and are used for indigestion, abdominal distension and bad breath, weak spleen and stomach, and less food intake without hunger; fried barley sprouts are better at digesting food and are used for less food intake without hunger; scorched barley sprouts are good at resolving stagnation and are used for indigestion. According to the "Chinese Pharmacopoeia" (2020 edition) and local processing specifications, fried barley sprouts and scorched barley sprouts can be obtained by different degrees of frying. Fried barley sprouts are made by frying raw barley sprouts until the surface is dark yellow and has an aroma, while scorched barley sprouts are made by frying raw barley sprouts until the surface is burnt yellow and has a burnt aroma. Currently, the degree of frying of barley sprouts is only judged by their appearance, color and smell. These judgment methods are all sensory judgments, which are inaccurate and subjective due to individual differences. They can easily lead to different degrees of frying of barley sprout products and cause differences in clinical efficacy.

[0003] At present, there are few quality control methods for raw barley sprouts and their processed products. The quality standards for barley sprouts and their processed products included in the Chinese Pharmacopoeia (2020 edition) only stipulate standard limits for properties, microscopic and inspection items, but lack the distinction between raw and processed products. At present, there are few studies on barley sprouts and their processed products. The literature reports only compare the content of α-amylase activators, types of digestive enzymes and biological activities of different processed products from the perspective of barley sprouts' digestive efficacy, and analyze the color quantification technology model based on a colorimeter from the perspective of color differences of processed products. The above data are collected by collecting raw barley sprouts, fried barley sprouts and scorched barley sprouts on the market, and the range of differences between different processed products is determined by statistical analysis of the values. It has a certain reference significance for the judgment of different barley sprout processed products, but it still lacks guidance for the interpretation of the processing process. At the same time, the accuracy of its values ​​depends on the accurate assessment of the degree of processing of the processed products used, and it also needs to rely on the accurate judgment of the processing end point. In the existing technology, the processing specifications of various provinces for barley sprouts, stir-fried barley sprouts, and scorched barley sprouts are only a brief summary of the processing methods, lacking specific processing parameters. The judgment of the processing endpoint is also consistent with the pharmacopoeia, judging by color and smell. There is no regulation on stir-frying time, and there is no objective data to measure the processing endpoint. Therefore, the judgment of the stir-frying endpoint is relatively vague. The judgment of the processing endpoint is an urgent problem to be solved in the processing of barley sprouts.

[0004] Therefore, how to provide an objective, accurate and clear method for judging the end point of the processing of stir-fried barley sprouts has become an urgent problem to be solved. Summary of the Invention

[0005] In response to the shortcomings of the prior art, the present invention aims to provide a method for determining the endpoint of stir-fried barley sprout processing and a stir-fried barley sprout processing process. The method provided by the present invention can objectively, accurately, and clearly determine the endpoint of stir-fried barley sprout processing, filling the gap in determining the endpoint of stir-fried barley sprout processing and compensating for the misjudgment that occurs when evaluating the endpoint based solely on color. It enables monitoring of the stir-fried barley sprout processing process and can effectively guide the stir-fried barley sprout processing process.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a method for determining the end point of processing of stir-fried barley sprouts, the method comprising the following steps:

[0008] (1) Mix the fried barley sprouts with different frying times with the alcohol solution and ultrasonically extract them to obtain a series of test solutions;

[0009] (2) The series of test sample solutions are subjected to liquid chromatography detection, and the peak area ratios of 4-coumaric acid and 5-hydroxymethylfurfural in the stir-fried barley sprouts at different stir-frying times are calculated according to the detection results. The time period corresponding to the stable peak area ratio range between the mutation points of the peak area ratio of 4-coumaric acid and 5-hydroxymethylfurfural is taken as the stir-frying time required to reach the processing end point, thereby judging the processing end point of the stir-fried barley sprouts.

[0010] Gullies sprouts are obtained by germinating the mature fruit of Setaria italica (L.) Beauv., a grass family plant. They consist of both the seeds and the sprouts. The seeds are rich in primary nutrients such as protein, starch, and fatty oils. During sprout germination, the sprouts produce a large number of secondary metabolites. The phenylpropanoid metabolic pathway is a key pathway in plant secondary metabolism, and 4-coumaryl-CoA is a key enzyme in this process, which is why all of these substances are found in the gullies sprouts. Stir-frying is a heat treatment of raw gullies sprouts. During the cooking process, proteins and carbohydrates undergo a Maillard reaction to produce 5-hydroxymethylfurfural, which changes the appearance and smell of the gullies sprouts. Heat also denatures 4-coumaryl-CoA, breaking it down into 4-coumaric acid. This cooking process alters the composition of the gullies sprouts, leading to changes in their efficacy. 5-Hydroxymethylfurfural has anti-inflammatory and antioxidant effects, improving chronic inflammation. 4-Coumaric acid scavenges free radicals, inhibits lipid peroxidation, inhibits tumor angiogenesis, inhibits platelet aggregation, and alleviates atherosclerosis. It promotes blood circulation, removes blood stasis, detoxifies, eliminates carbuncle, and promotes bile secretion. Analysis of the efficacy of stir-fried barley sprouts indicates that both 5-Hydroxymethylfurfural and 4-coumaric acid play a significant role in their efficacy, and therefore, their preservation should be emphasized during the processing process. Due to differences in the content of proteins, carbohydrates, and secondary metabolites, the changes in 5-Hydroxymethylfurfural and 4-coumaric acid during the processing process differ. 5-Hydroxymethylfurfural is positively correlated with its color change, making it a useful color indicator. The present invention monitors the ratio of the two during the processing process and finds that the color and smell of the fried barley sprouts within the stable peak area ratio range between the ratio mutation points meet the endpoint judgment requirements, and it is also the optimal degree of retention of the two chemical components. Therefore, the frying time corresponding to the stable peak area ratio range between the ratio mutation points is used as the processing endpoint, and the processing endpoint of the fried barley sprouts can be objectively, accurately and clearly judged, filling the gap in the judgment of the processing endpoint of the fried barley sprouts, compensating for the situation where misjudgment occurs when the processing endpoint is evaluated only by color, realizing the monitoring of the processing process of the fried barley sprouts, and being able to effectively guide the processing technology of the fried barley sprouts.

[0011] Preferably, the stir-frying temperature of the stir-fried barley sprouts in step (1) is 180-220°C, for example, 180°C, 190°C, 200°C, 210°C or 220°C, etc., but is not limited to the values ​​listed above. Other values ​​not listed within the above numerical range are also applicable.

[0012] Preferably, the alcohol solution in step (1) is a methanol-water solution.

[0013] Preferably, the volume fraction of the methanol aqueous solution is 50-70%, such as 50%, 55%, 60%, 65% or 70%, etc., but is not limited to the values ​​listed above. Other values ​​not listed within the above numerical range are also applicable.

[0014] Preferably, the ultrasonic extraction time in step (1) is more than 30 minutes.

[0015] Preferably, the chromatographic column for liquid chromatography detection in step (2) is a C18 chromatographic column.

[0016] Preferably, the mobile phase for the liquid chromatography detection in step (2) comprises mobile phase A and mobile phase B, wherein the mobile phase A comprises acetonitrile and the mobile phase B comprises an acetic acid aqueous solution.

[0017] Preferably, the mass fraction of the acetic acid aqueous solution is 0.3-0.7%, such as 0.3%, 0.4%, 0.5%, 0.6% or 0.7%, etc., but is not limited to the values ​​listed above. Other values ​​not listed within the above numerical range are also applicable.

[0018] Preferably, the liquid chromatography detection in step (2) adopts a gradient elution method, and the procedure of the gradient elution is as follows:

[0019] From 0 to 15 minutes, the volume fraction of mobile phase A was changed uniformly from 4-6% to 9-11%, and the rest was mobile phase B;

[0020] From 15 to 17 minutes, the volume fraction of mobile phase A was changed at a constant rate from 9 to 11% to 13 to 15%, and the rest was mobile phase B;

[0021] From 17 to 50 minutes, the volume fraction of mobile phase A changed at a constant rate from 13-15% to 18-22%, and the rest was mobile phase B.

[0022] Preferably, the column temperature of the liquid chromatography detection in step (2) is 28-32°C, for example, 28°C, 29°C, 30°C, 31°C or 32°C, but is not limited to the values ​​listed above. Other values ​​not listed within the above numerical range are also applicable.

[0023] Preferably, the mobile phase flow rate of the liquid chromatography detection in step (2) is 0.7-0.9 mL / min, for example, 0.7 mL / min, 0.75 mL / min, 0.8 mL / min, 0.85 mL / min or 0.9 mL / min, but is not limited to the values ​​listed above. Other values ​​not listed within the above numerical range are also applicable.

[0024] The above-mentioned specific reagents and parameter control can effectively improve the accuracy of the detection process, thereby improving the accuracy of endpoint judgment.

[0025] Preferably, the peak area ratio in step (2) is in the range of 0.95-1.18.

[0026] Preferably, the frying time required to reach the end point of the preparation in step (2) is 15-22 minutes.

[0027] In a second aspect, the present invention further provides a process for preparing stir-fried barley sprouts, the process comprising the following steps:

[0028] Stir-frying the raw barley sprouts until the stir-frying time reaches the end point of the preparation, thereby obtaining stir-fried barley sprouts;

[0029] The stir-frying time required to reach the processing end point is obtained by the method for judging the processing end point of stir-fried barley sprouts as described above.

[0030] Preferably, the stir-frying temperature is 180-220°C, such as 180°C, 190°C, 200°C, 210°C or 220°C, but is not limited to the values ​​listed above. Other values ​​not listed within the above numerical range are also applicable.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The invention provides a method for judging the processing endpoint of stir-fried barley sprouts. By monitoring the ratio of 4-coumaric acid to 5-hydroxymethylfurfural peak surfaces during the processing process, and taking the stir-frying time corresponding to the stable peak area ratio range between ratio mutation points as the processing endpoint, the method can objectively, accurately and clearly judge the processing endpoint of the stir-fried barley sprouts, fills the gap in judging the processing endpoint of the stir-fried barley sprouts, makes up for the situation where misjudgment occurs when the processing endpoint is evaluated only by color, realizes the monitoring of the processing process of the stir-fried barley sprouts, and can effectively guide the processing technology of the stir-fried barley sprouts. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 1 is a diagram showing the liquid phase detection results of stir-fried millet sprouts at different stir-frying times in Example 1. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0035] Example 1

[0036] This embodiment provides a method for determining the end point of stir-fried barley sprouts, and the specific steps are as follows:

[0037] Instruments: Shimadzu 2010AHT high-performance liquid chromatograph, UV detector, LabSolutions operating system; ME104E electronic balance (Mettler Toledo), JY20002 electronic balance (Mettler Toledo), KQ-300DB ultrasonic cleaner (Kunshan Ultrasonic Instrument Co., Ltd.); electronic constant temperature water bath DZKW-4 (Beijing Zhongxing Weiye Instrument Co., Ltd.).

[0038] Chromatographic column: (4.6×250mm, 5μm).

[0039] Test drug: stir-fried barley sprouts (lot numbers: K498CP01, K498CP02, K498CP03, K498CP04, K498CP05, K498CP6);

[0040] 4-Coumaric acid reference substance (batch number: 112037-201801, purity 99.3%, China Food and Drug Administration);

[0041] 5-Hydroxymethylfurfural (batch number: 111626-201912, purity 98.7%, China Food and Drug Administration);

[0042] Reagents: acetonitrile (chromatographic grade, Fisher Chemical); acetic acid (chromatographic grade, Fisher Chemical); distilled water (Watson); other reagents were of analytical grade.

[0043] Take an appropriate amount of 4-coumaric acid reference substance, accurately weigh it, and add methanol to make a solution containing 20 μg per 1 mL; take an appropriate amount of 5-hydroxymethylfurfural reference substance, accurately weigh it, and add methanol to make a solution containing 10 μg per 1 mL as the reference substance solution.

[0044] Take a wok, heat it to 200℃, add 1000g of raw barley sprout slices (K498CP01), stir-fry, take out 100g at 5min, 10min, 15min, 18min, 20min, 22min, 25min, 30min, 35min, and 40min respectively, let it cool, and use them as fried barley sprout samples with different frying times.

[0045] Take appropriate amount of fried barley sprout slices with different frying times, crush them, take 1.0 g of powder (pass through No. 4 sieve), accurately weigh, accurately add 50 mL of 50% methanol, plug, weigh, and ultrasonically treat (power 390 W, frequency 40 kHz) for 30 minutes. Take out, cool, filter, concentrate the filtrate to 5 mL, transfer to a 10 mL volumetric flask, dilute to the scale with 50% methanol, shake well, and filter to obtain the test solution of fried barley sprout with different frying times.

[0046] The stir-fried barley sprout test solution with different stir-frying time and the reference substance solution were subjected to liquid chromatography detection, and the detection conditions were as follows:

[0047] Use acetonitrile as mobile phase A and 0.5% acetic acid solution as mobile phase B, and perform gradient elution as specified in the table below; flow rate: 0.8 mL / min; column temperature: 35°C; detection wavelength: 310 nm. The theoretical plate number calculated based on the 4-coumaric acid peak should be no less than 5000.

[0048]

[0049] The results are as follows Figure 1 Peak 1 is 5-hydroxymethylfurfural, and peak 4 is 4-coumaric acid. The peak areas and ratios of each group are as follows (0 min represents raw barley sprouts):

[0050] Peak area statistics table of Peak 1 and Peak 4

[0051]

[0052]

[0053] It can be seen that with the increase of frying time, the peak area ratio of peak 4 to peak 1 is gradually decreasing. It can also be seen from the figure that peak 1 is increasing, and peak 4 first increases and then decreases. When the frying time is 15-22 minutes, the change trend is relatively stable. Combined with the color judgment method, the color of the fried barley sprout slices is judged. When the frying time is 15-22 minutes, the color is dark yellow, which meets the judgment standard of fried barley sprout in the pharmacopoeia. Continue frying. When the frying time is more than 25 minutes, the relative peak area ratio of peak 4 to peak 1 is significantly reduced, and the color of the fried barley sprout also changes from dark yellow to burnt brown. In summary, the processing end point is determined to be 15-22 minutes, and the peak area ratio of peak 4 to peak 1 ranges from 0.95 to 1.18.

[0054] Example 2

[0055] Investigation and verification of characteristic mapping method:

[0056] The preparation methods of the test sample solutions in the characteristic spectra were investigated, including the extraction solvent, extraction concentration and extraction method.

[0057] 1. Investigation of extraction solvent

[0058] Take an appropriate amount of barley malt slices with a frying time of 20 minutes, crush them, take 7 parts of powder (pass through No. 4 sieve), 1.0 g each, accurately weighed, placed in a stoppered conical flask, accurately added 50 mL of appropriate solvent (water, 70% ethanol, 50% ethanol, 70% methanol, 50% methanol, methanol), plugged, weighed, and ultrasonically treated (power 250 W, frequency 40 kHz) for 30 minutes. Take out, cool, weigh again, make up the lost weight with the corresponding solvent, shake well, filter, concentrate the filtrate to 5 ml, transfer to a 10 mL volumetric flask, dilute to the scale with the corresponding solvent, shake well, filter, accurately draw 10 μ L of the filtrate, and inject it into a high performance liquid chromatograph; determine the peak area of ​​each characteristic peak according to the chromatographic conditions of Example 1, and the results are shown in the table below.

[0059]

[0060]

[0061] Summary: The above results show that 50% methanol extraction has the highest content, followed by 70% methanol, and the difference is not large. Considering that the content of 4-coumaric acid in roasted barley sprout granules is extremely low and the method is simple and easy to use, the extraction solvent is determined to be 50-70% methanol.

[0062] 2. Investigation of extraction methods

[0063] Take an appropriate amount of barley malt slices with a frying time of 20 minutes, crush them, take 6 parts of powder (pass through No. 4 sieve), 1.0g each, accurately weighed, placed in a stoppered conical flask, numbered as test solution 1-6, accurately added 50mL of 50% methanol, plugged, and weighed, wherein the extraction method of test solution 1 and 2 was ultrasonic (power 250W, frequency 40kHz) 30min; wherein the extraction method of test solution 3 and 4 was reflux extraction 30 minutes; wherein the extraction method of test solution 5 and 6 was extraction by shaking for 30 minutes; the above test solution was taken out, cooled, weighed again, made up the lost weight with 50% methanol, shaken, filtered, and the filtrate was concentrated to 5ml, transferred to a 10mL volumetric flask, diluted to the scale with 50% methanol, shaken, filtered, and accurately drawn 10μL of the above test sample filtrate, injected into a high performance liquid chromatograph, measured according to the chromatographic conditions of Example 1, measured the peak area, and the results are shown in the table below.

[0064]

[0065]

[0066] Summary: Comparison of the results of different extraction methods shows that the peak areas of 5-hydroxymethylfurfural and 4-coumaric acid obtained by ultrasonic treatment and reflux extraction are slightly different, while the peak areas of the two peaks obtained by shaking extraction are quite different from those of the other two extraction methods. Therefore, considering the simplicity and accuracy of the sample preparation method, ultrasonic extraction was used as the extraction method for the sample.

[0067] 3. Methodological Investigation

[0068] Take an appropriate amount of barley malt slices fried for 20 minutes, crush them, take 6 portions of powder (pass through No. 4 sieve), 1.0 g each, and prepare precision test solutions according to the test sample preparation method determined in Example 2, which are marked as test solutions 1 to 6 respectively.

[0069] The above stir-fried barley sprout test solution and the reference substance solution were subjected to liquid chromatography detection under the following conditions:

[0070] Use acetonitrile as mobile phase A and 0.5% acetic acid solution as mobile phase B. Gradient elution should be performed as specified in the table below. The flow rate should be 0.8 mL / min. The column temperature should be 35°C. The detection wavelength should be 310 nm. The theoretical plate number calculated based on the 4-coumaric acid peak should be no less than 5000.

[0071]

[0072] 3.1 Precision

[0073] Take test solution 1 and perform the gradient elution test six times. Calculate the peak areas of the characteristic peaks of 5-hydroxymethylfurfural (peak 1) and 4-coumaric acid (peak 3). Calculate the RSD of the six characteristic peak areas. See the table below.

[0074]

[0075] According to the precision investigation results, the RSD of the peak areas of the characteristic peaks of 5-hydroxymethylfurfural and 4-coumaric acid were in the range of 0.12% to 0.13%, indicating that the precision of this method was good.

[0076] 4.2 Repeatability

[0077] Take test sample solutions 1 to 6 and measure them according to the gradient elution procedure. Calculate the peak areas of the characteristic peaks of 5-hydroxymethylfurfural (peak 1) and 4-coumaric acid (peak 3). Calculate the RSD of the peak areas of the six characteristic peaks, as shown in the table below.

[0078]

[0079] According to the results of repeatability investigation, the RSD of the peak areas of the characteristic peaks of 5-hydroxymethylfurfural and 4-coumaric acid were in the range of 0.39% to 0.49%, indicating that the method had good repeatability.

[0080] 4.3 Stability

[0081] Take test solution 6 and perform a gradient elution procedure at the following times: 0h, 3h, 6h, 9h, 12h, 18h, and 24h. Calculate the peak areas of the characteristic peaks of 5-hydroxymethylfurfural (peak 1) and 4-coumaric acid (peak 3) at different times. Calculate the RSD of the peak areas of the six characteristic peaks, as shown in the table below.

[0082]

[0083] Summary: According to the results of the repeatability test, the RSD of the peak areas of the characteristic peaks of 5-hydroxymethylfurfural and 4-coumaric acid were in the range of 0.14-0.29%, indicating that the characteristic components in the solution had good stability within 24 hours.

[0084] Example 3

[0085] Ten batches of stir-fried barley sprout slices were randomly purchased from the market and tested according to the characteristic spectrum determination method in Example 1. The properties of the purchased stir-fried barley sprout slices were recorded according to the item "Properties" of stir-fried barley sprout in the pharmacopoeia. Two experts who have been engaged in the identification of medicinal slices for more than 10 years were asked to judge the color and qualification of the purchased medicinal slices. The results are shown in the following table.

[0086]

[0087]

[0088] The data in the table above show that the color and odor of 10 batches of roasted barley sprout slices randomly purchased from the market all met the requirements in the pharmacopoeia. However, after appraisal by industry experts, three batches were found to be substandard, with an accuracy rate of only 70%. This indicates that using color and odor alone as the criteria for evaluating roasted barley sprout slices carries risks. The roasted barley sprout characteristic pattern method provided by the present invention, when compared with the results of appraisal by authoritative industry experts, achieved an accuracy rate of 90%, demonstrating that the endpoint determination method for roasted barley sprout slices provided by the present invention is accurate and objective.

[0089] Among them, sample 7 purchased from the market is a counterfeit fried barley sprout decoction piece, which is obtained by processing barley sprouts that have not fully sprouted or have sprouted to an insufficient length. Its color conforms to the dark yellow characteristics of fried barley sprouts in the "Chinese Pharmacopoeia", but it is judged as an unqualified product by experts, and obvious differences can also be found using characteristic spectrum identification.

[0090] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the method for determining the endpoint of the processing of stir-fried barley sprouts and the stir-fried barley sprout processing process of the present invention, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. It should be clear to those skilled in the art that any improvement of the present invention, equivalent replacement of the raw materials of the product of the present invention, addition of auxiliary ingredients, selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

[0091] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0092] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for determining the end point of stir-fried barley sprouts, characterized in that: The method for judging the end point of the stir-fried barley sprouts processing comprises the following steps: (1) Mix the fried barley sprouts with different frying times with the alcohol solution and ultrasonically extract them to obtain a series of test solutions; (2) The series of test sample solutions are subjected to liquid chromatography detection, and the peak area ratios of 4-coumaric acid and 5-hydroxymethylfurfural in the stir-fried barley sprouts at different stir-frying times are calculated according to the detection results. The time period corresponding to the stable peak area ratio range between the mutation points of the peak area ratio of 4-coumaric acid and 5-hydroxymethylfurfural is taken as the stir-frying time required to reach the processing end point, thereby judging the processing end point of the stir-fried barley sprouts.

2. The method for determining the endpoint of the processing of stir-fried barley sprouts according to claim 1, wherein: The stir-frying temperature of the stir-fried barley sprouts in step (1) is 180-220° C. Preferably, the alcohol solution in step (1) is a methanol-water solution; Preferably, the volume fraction of the methanol aqueous solution is 50-70%.

3. The method for determining the endpoint of the processing of stir-fried barley sprouts according to claim 1 or 2, wherein: The ultrasonic extraction time in step (1) is more than 30 minutes.

4. The method for determining the end point of stir-fried barley sprouts according to any one of claims 1 to 3, wherein: The chromatographic column for liquid chromatography detection in step (2) is a C18 chromatographic column.

5. The method for determining the end point of the processing of stir-fried barley sprouts according to any one of claims 1 to 4, characterized in that: The mobile phase for the liquid chromatography detection in step (2) comprises mobile phase A and mobile phase B, wherein the mobile phase A comprises acetonitrile and the mobile phase B comprises an acetic acid aqueous solution; Preferably, the mass fraction of the acetic acid aqueous solution is 0.3-0.7%; Preferably, the liquid chromatography detection in step (2) adopts a gradient elution method, and the procedure of the gradient elution is as follows: From 0 to 15 minutes, the volume fraction of mobile phase A was changed uniformly from 4-6% to 9-11%, and the rest was mobile phase B; From 15 to 17 minutes, the volume fraction of mobile phase A was changed at a constant rate from 9 to 11% to 13 to 15%, and the rest was mobile phase B; From 17 to 50 minutes, the volume fraction of mobile phase A changed at a constant rate from 13-15% to 18-22%, and the rest was mobile phase B.

6. The method for determining the end point of the processing of stir-fried barley sprouts according to any one of claims 1 to 5, characterized in that: The column temperature of the liquid chromatography detection in step (2) is 28-32°C; Preferably, the mobile phase flow rate of the liquid chromatography detection in step (2) is 0.7-0.9 mL / min.

7. The method for determining the end point of the processing of stir-fried barley sprouts according to any one of claims 1 to 6, characterized in that: The peak area ratio in step (2) is in the range of 0.95-1.

18.

8. The method for determining the end point of the processing of stir-fried barley sprouts according to any one of claims 1 to 7, characterized in that: The frying time required to reach the processing end point in step (2) is 15-22 minutes.

9. A process for preparing fried barley sprouts, characterized in that: The process for preparing the stir-fried barley sprouts comprises the following steps: Stir-frying the raw barley sprouts until the stir-frying time reaches the end point of the preparation, thereby obtaining stir-fried barley sprouts; The stir-frying time required to reach the processing end point is obtained by the method for judging the processing end point of stir-fried barley sprouts according to any one of claims 1-8.

10. The process for preparing stir-fried barley sprouts according to claim 9, wherein: The stir-frying temperature is 180-220°C.

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