Method for optimizing pressing process of folium isatidis mouth decoction pieces

Abstract

The invention relates to an optimization method for a pressing process of folium isatidis mouth decoction pieces, which can overcome the defects of leaf medicinal materials in production, transportation and application, and can be used for preparing the folium isatidis mouth decoction pieces by taking a single-factor test as a basis, combining a Box-Behnken design-response surface method and taking indirubin, tryptanthrin, isovitexin and water-soluble extracts as comprehensive evaluation indexes. Four factors including pressing time, pressure, baking temperature and baking time are investigated, an analytic hierarchy process and an entropy weight method are utilized to calculate weight coefficients and comprehensive scores of all indexes to determine the optimal pressing process of the folium isatidis mouth decoction pieces, and the optimal pressing process is close to a predicted value of a result obtained by actual operation, which shows that the process optimization method is good in predictability and high in practicability. The technology is stable and feasible, actual production can be directly guided, the problems of fuzzy technological parameters, large decoction piece quality fluctuation and the like in production are solved, key technical reference can be provided for standardized formulation of the folium isatidis mouth decoction piece pressing technology, and the practical application and popularization value is achieved.

Description

I. Technical Field

[0001] This invention relates to the field of traditional Chinese medicine, and in particular to an optimized method for pressing processed slices of Isatis tinctoria leaves. II. Background Technology

[0002] Isatis indigotica Fort., a plant in the Brassicaceae family, is a dried leaf of the plant. It is bitter and cold in nature, and enters the heart and stomach meridians. It has the functions of clearing heat and detoxifying, cooling the blood and eliminating spots. Clinically, it is often used for fever, cough and sore throat caused by lung heat, and viral infectious diseases such as influenza. Modern research shows that the effective active ingredients in Isatis indigotica are alkaloids (indirubin, tryptamine) and flavonoids (isovitanyl), which have pharmacological effects such as antibacterial, anti-endotoxin, antitumor, antiviral, anti-inflammatory, immune-enhancing, antioxidant, and protection against mental illness and the cardiovascular system.

[0003] Ancient texts primarily describe the processing of Isatis tinctoria leaves for raw use or air-drying, and current processing methods also mainly involve sun-drying. The low density, poor flowability, and large volume of leaf-based medicinal materials increase the difficulties in production, packaging, storage, transportation, and dispensing. Pressing, as a traditional processing method, produces pressed medicinal slices that adhere to traditional Chinese medicine theories and unique processing techniques, thus addressing the drawbacks of leaf-based medicinal materials in production, transportation, and application. Therefore, improving and innovating the pressing process for pressed Isatis tinctoria leaves is an urgent issue that needs to be addressed. III. Summary of the Invention

[0004] To address the above-mentioned issues and overcome the shortcomings of existing technologies, the present invention aims to provide an optimization method for the pressing process of Daqingye (Isatis tinctoria) sliced ​​medicinal herbs. Based on single-factor experiments and combined with Box-Behnken design-response surface methodology, the method uses indirubin, tryptophan, isovitexin, and water-soluble extract as comprehensive evaluation indicators to examine four factors: pressing time, pressure, drying temperature, and drying time. The method utilizes the analytic hierarchy process (AHP) and entropy weight method to calculate the weight coefficients of each indicator and the comprehensive score to determine the optimal pressing process for Daqingye sliced ​​medicinal herbs.

[0005] The technical solution provided by this invention is an optimized method for pressing Daqingye (Isatis tinctoria) sliced ​​medicinal herbs, comprising the following steps:

[0006] S1. After removing impurities from the dried Isatis tinctoria leaves, spray them with moisture. When they can be clumped together by hand but crumble when released, cut them into pieces.

[0007] S2. The cutting range of Daqingye was analyzed by considering its formability, yield, and demolding difficulty. Based on the results, the cutting range of Daqingye was initially obtained, and the cutting range with good formability and the highest yield was identified as the optimal cutting range.

[0008] S3. Based on the preliminary determination of the cutting range of Daqingye, the weight coefficients of each evaluation index are determined by AHP and entropy weight method, respectively, using indirubin, isovitexin, tryptophan, and water-soluble extract as comprehensive evaluation indicators. The comprehensive weight of each evaluation index is calculated by combining the weight coefficients determined by AHP and entropy weight method, and the comprehensive score calculation formula is obtained through the comprehensive weight result.

[0009] S4. Using pressure, pressing time, drying temperature, and drying time as single-factor variables, the evaluation indicators of Daqingye under different pressures, pressing times, drying temperatures, and drying times are comprehensively scored using a comprehensive scoring formula.

[0010] S5. Based on the comprehensive scoring results, determine the indicators for the response surface optimization experiment. Using pressing time, drying temperature, and drying time as indicators, and the comprehensive score as the response value, conduct the response surface optimization experiment to determine the optimal pressing process for Daqingye (Isatis indigotica) sliced ​​medicinal pieces.

[0011] In S2, the cutting range of the Daqingye (Isatis tinctoria) slices is 5-7 mm.

[0012] In S3, the method for calculating the weighting coefficients using AHP is as follows: based on the main active ingredient and extract that reflects the overall level in Isatis indigotica, the evaluation indicators are ranked as follows: indigo > tryptamine > isovitexin > water-soluble extract.

[0013] In the S3 described above, the method for calculating the weight coefficients using the entropy weight method is as follows: the original data of the index components are normalized according to formula (1); then the information entropy is calculated according to formulas (2) and (3), where m refers to the number of objects being evaluated and n refers to the number of evaluation indicators; finally, the objective weight Wj of each index component is calculated according to formula (4).

[0014]

[0015] The meanings of each letter are as follows:

[0016] d ij : The standardized value of the i-th sample under the j-th indicator (the value after range standardization);

[0017] y ij : The original data of the j-th indicator of the i-th sample;

[0018] y ijmax The maximum value of the j-th indicator among all samples;

[0019] y ijmin The minimum value of the j-th indicator among all samples;

[0020] e jThe entropy value of the j-th index;

[0021] m: Number of samples;

[0022] p ij The standardized value of the j-th indicator in the i-th sample is the proportion of the total standardized values ​​of all samples of that indicator.

[0023] w j The weight of the j-th indicator;

[0024] n: The number of indicators.

[0025] In S3, the method for determining the comprehensive weight and score is as follows: combine the weight coefficients determined by the AHP method and the entropy weight method, use formula (5) to calculate the comprehensive weight, and combine the indicators of the evaluated object to calculate the comprehensive score using formula (6).

[0026]

[0027]

[0028] Among them, W i For the weights of each indicator determined by AHP, W j β represents the weights of each index determined by the entropy weight method. j The overall weight of the j-th indicator, OD ijP : The comprehensive score of the j-th indicator for the i-th sample.

[0029] In S5, the response surface optimization experiment, using Design-Expert 13.0 software and following the central composite design principle, yielded the quadratic multiple regression equation Y = 92.34 + 3.02A + 0.7973B + 4.35C + 3.15AB - 3.29AC - 2.04BC - 3.20A. 2 -6.51B 2 -0.9684C 2 Where A represents baking temperature, B represents baking time, and C represents pressing time.

[0030] In S5, the optimal pressing process for Daqingye (Isatis tinctoria) slices is as follows: pressure 4 MPa, drying temperature 58.538℃, drying time 4.140 h, and pressing time 77.108 s. Based on actual production, the parameters are adjusted to be: for every 100 g of medicinal material, after moistening, cut into 5-7 mm pieces, press at 4 MPa for 60 s, and then dry at 60℃ for 4 h.

[0031] The beneficial technical effects of this invention are:

[0032] 1. The method of the present invention first analyzes three different specifications of Daqingye segments (1-3mm, 5-7mm, and 9-11mm) based on their properties and pressing effect to preliminarily determine the cutting range. This process starts from the perspective of the physical morphology of the slices and their compatibility with subsequent pressing, avoiding problems such as easy breakage and poor shaping during pressing caused by improper cutting specifications. This lays the foundation for subsequent process optimization that meets actual production needs and ensures the basic properties and quality of Daqingye slices.

[0033] 2. Indirubin, tryptophan, isovitelline, and water-soluble extracts were selected as evaluation indicators. This not only includes the characteristic active components of Isatis indirubin (indirubin, tryptophan, and isovitelline) in Daqingye, but also takes into account the water-soluble extracts that reflect the overall dissolution performance of the decoction pieces. This comprehensively covers the two key quality dimensions of the decoction pieces: the pharmacodynamic material basis and the dissolution efficiency. It avoids the limitations of single-indicator evaluation and can more objectively and comprehensively reflect the quality level of Daqingye decoction pieces.

[0034] 3. The comprehensive weighting is determined by combining AHP (Analytic Hierarchy Process) and entropy weighting, which combines the advantages of both subjective and objective methods. AHP can fully integrate experts' professional understanding of the importance of each evaluation indicator, reflecting its practical application value; entropy weighting can objectively assign weights based on the dispersion of the indicator data itself, reducing subjective experience bias. The combination of these two methods effectively balances the influence of subjective judgment and objective data, making the weight coefficients of each evaluation indicator more reasonable, thereby improving the reliability and scientific rigor of the subsequent comprehensive scoring.

[0035] 4. Response surface methodology (RSM) experiments are conducted using selected key indicators as variables and comprehensive scores as response values. By establishing a mathematical model between variables and response values, the impact of the interactions between variables on the quality of the processed medicinal slices can be visually presented, accurately determining the optimal pressing process parameters for Daqingye (Isatis tinctoria) processed medicinal slices. Compared to traditional single-variable optimization, RSM can more comprehensively examine the synergistic effects between variables, and the resulting optimal process parameters are more in line with actual production needs, effectively ensuring the stability and uniformity of the processed medicinal slices' quality.

[0036] 5. The optimal result obtained from the response surface methodology of the optimization method for pressing Daqingye (Isatis tinctoria) slices is close to the predicted value obtained from actual operation, indicating that the optimization method of the present invention has good predictive ability and the process is stable and feasible. It effectively solves the drawbacks of leafy medicinal materials in production, transportation and application, and provides technical support for the pressing process of Daqingye slices. It can not only directly guide actual production and solve problems such as fuzzy process parameters and large fluctuations in slice quality, but also provide key technical references for the standardization of the pressing process of Daqingye slices, and has practical application and promotion value. IV. Description of the attached drawings

[0037] Figure 1This is a three-dimensional response surface plot showing the relationship between baking temperature and baking time and overall score in this invention.

[0038] Figure 2 This is a three-dimensional response surface plot showing the relationship between baking temperature and pressing time and overall score in this invention.

[0039] Figure 3 This is a three-dimensional response surface plot showing the relationship between the baking time, pressing time, and overall score of this invention. V. Detailed Implementation Methods

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1

[0042] In its specific implementation, this invention includes the following steps:

[0043] S1. After removing impurities from the dried Isatis tinctoria leaves, spray them with moisture. When they can be clumped together by hand but crumble when released, cut them into pieces.

[0044] S2. The cutting range of Daqingye was analyzed by considering its formability, yield, and ease of demolding. Finally, the cutting range of Daqingye slices was determined to be 5-7 mm.

[0045] S3. Based on the preliminary determination of the cutting range of Daqingye, the weight coefficients of each evaluation index are determined by AHP and entropy weight method, respectively, using indirubin, isovitexin, tryptophan, and water-soluble extract as comprehensive evaluation indicators. The weight coefficients determined by AHP and entropy weight method are combined to calculate the comprehensive weight of each evaluation index. The comprehensive score calculation formula is obtained through the comprehensive weight result. The method for determining the comprehensive weight and score is as follows: the weight coefficients determined by AHP method and entropy weight method are combined, and the comprehensive weight is calculated by formula (5). The comprehensive score is calculated by formula (6) in combination with the indicators of the evaluated object.

[0046]

[0047] Among them, W i For the weights of each indicator determined by AHP, W j The weights of each indicator determined by the entropy weight method;

[0048] S4. Using pressure, pressing time, drying temperature, and drying time as single-factor variables, the evaluation indicators of Daqingye under different pressures, pressing times, drying temperatures, and drying times are comprehensively scored using a comprehensive scoring formula.

[0049] S5. Based on the comprehensive scoring results, determine the indicators for the response surface methodology (RSM) optimization experiment. Using pressing time, drying temperature, and drying time as indicators, and the comprehensive score as the response value, conduct the RSM optimization experiment to determine the optimal pressing process for Daqingye (Isatis indigotica) slices. The RSM optimization experiment utilizes Design-Expert 13.0 software and follows the central composite design principle to obtain the quadratic multiple regression equation Y = 92.34 + 3.02A + 0.7973B + 4.35C + 3.15AB - 3.29AC - 2.04BC - 3.20A. 2 -6.51B 2 -0.9684C 2 Where A represents the drying temperature, B represents the drying time, and C represents the pressing time; the optimal pressing process for the Daqingye (Isatis tinctoria) sliced ​​medicinal material is: pressure 4 MPa, drying temperature 58.538℃, drying time 4.140h, and pressing time 77.108s. Based on actual production, the parameters are adjusted as follows: for every 100g of medicinal material, after moistening, cut into 5-7mm pieces, press at 4 MPa for 60s, and then dry at 60℃ for 4h.

[0050] This invention analyzes the characteristics and pressing effects of Isatis indigotica leaf segments of 1-3mm, 5-7mm, and 9-11mm. Based on the results, the cutting range of Isatis indigotica leaves is initially determined. Using indigo carmine, tryptophan, isovitexin, and water-soluble extracts as evaluation indicators, the weight coefficients of each indicator are determined using the Analytic Hierarchy Process (AHP) and entropy weight method. The weight coefficients determined by AHP and entropy weight method are combined to calculate the comprehensive weight of each evaluation indicator. A comprehensive score calculation method is obtained based on the comprehensive weight result. Pressing time, pressure, drying temperature, and drying time are used as single-factor variables. The comprehensive score calculation formula obtained by the AHP-entropy weight method is used to comprehensively score the evaluation indicators of Isatis indigotica leaves under different pressing times, pressures, drying temperatures, and drying times. Based on the comprehensive score results, the indicators for response surface methodology (RSM) optimization experiments are determined. Using pressing time, drying temperature, and drying time as indicators, and the comprehensive score as the response value, RSM optimization experiments are conducted to determine the optimal pressing process for Isatis indigotica leaf slices. Relevant experimental data are as follows:

[0051] It should be noted that all technical terms used in this invention are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments can be purchased from the market or prepared by existing methods.

[0052] 1. Instruments

[0053] FA2140B electronic balance (Shanghai Yueping Scientific Instruments (Suzhou) Manufacturing Co., Ltd.); ZNHW intelligent constant temperature electric heating mantle (Gongyi Yuhua Instrument Co., Ltd.); UPR-Ⅱ-10TNZP UPU series ultrapure water system (Sichuan UPU Ultrapure Technology Co., Ltd.); pneumatic press (Yueqing Minxiang Electric Co., Ltd.); DHG-9030A forced-air drying oven (Shanghai Yiheng Scientific Instrument Co., Ltd.); HH-6 digital display constant temperature water bath (Shanghai Lichen Bangxi Instrument Technology Co., Ltd.); constant temperature drying oven (Tianjin Laipolite Instrument Equipment Co., Ltd.); 4-hole tableting mold with a diameter of 18.00mm and a depth of 13.80mm (pharmaceutical tableting machine direct sales store); evaporating dish.

[0054] 2. Medicinal materials and reagents

[0055] The Daqingye (Shangqiu, Henan) was identified by Professor Li Kai of Henan University of Traditional Chinese Medicine as the dried leaves of Isatis indigoti ca Fort., a plant of the Brassicaceae family, and its quality meets the quality standards of the 2020 edition of the Chinese Pharmacopoeia after quality inspection.

[0056] Isovitin (batch number A29HB193210), tryptophan (batch number M18HS179375), and indirubin (batch number J19A10T95563), all with a mass fraction ≥97%, were purchased from Shanghai Yuanye Biotechnology Co., Ltd.; methanol was chromatographic grade (Tianjin Fuyu Fine Chemical Co., Ltd.); acetonitrile was chromatographic grade (Anhui Tiandi High Purity Co., Ltd.); formic acid (chromatographic grade, Thermo Fisher Scientific (China) Co., Ltd.); the remaining reagents were analytical grade; and double-distilled water was used in the experiments.

[0057] The optimization method is as follows:

[0058] (1) The Isatis tinctoria leaf was moistened and then cut into strips of three sizes: 1-3 mm, 5-7 mm, and 9-11 mm. The degree of fragmentation of Isatis tinctoria leaf was analyzed based on its formability, yield, and ease of demolding. The preliminary cutting range of Isatis tinctoria leaf was determined based on the results. An examination of different sizes of Isatis tinctoria leaf fragments revealed the following problems during the pressing and drying process: the 9-11 mm fragments were easily squeezed into the mold, making demolding difficult; the formability was poor, with approximately 60% of the sliced ​​pieces scattering after standing for a period of time; after drying, 62.5% of the 9-11 mm sliced ​​pieces broke into two parts, resulting in significant loss. The 1-3 mm fragmented pieces exhibited the following problems during the pressing and drying process: they were easily scattered after pressing, resulting in greater loss; the yield after drying was lower than that of the 5-7 mm fragmented pieces. In the study of water-soluble extracts, the average yield of extract from 1-3mm slices was 33.68%, and the average yield from 5-7mm slices was 33.15%, showing little difference. Therefore, 5-7mm was selected as the cutting size for Isatis indigotica leaf slices.

[0059] (2) Based on the preliminary determination of the cutting range of Daqingye, the content of indigo, tryptophan, isovitexin and water-soluble extracts are used as evaluation indicators. The weight coefficients of each evaluation indicator are determined by AHP and entropy weight method respectively. The weight coefficients determined by AHP and entropy weight method are combined to calculate the comprehensive weight of each evaluation indicator. The comprehensive score calculation formula is obtained through the comprehensive weight result.

[0060] 3. Chromatographic conditions

[0061] The chromatographic column was an Ecosil C18 (250 mm × 4.6 mm, 5 μm). Methanol was used as mobile phase A, and 0.1% formic acid as mobile phase B. Gradient elution conditions were: 0–5 min, 10% A; 5–10 min, 10%–20% A; 10–20 min, 20%–30% A; 20–45 min, 30%–40% A; 45–60 min, 40%–45% A; 60–90 min, 45%–75% A; 90–110 min, 75%–80% A; flow rate: 0.4 mL / min. -1 The column temperature was 35℃, and the detection wavelength was 289nm. The injection volume was 10μL.

[0062] 4. Preparation of the test solution

[0063] Weigh 1.0g of Daqingye (Isatis tinctoria) powder (passed through a No. 5 sieve), place it in a stoppered conical flask, accurately add 30mL of 65% methanol, seal tightly, weigh, sonicate for 30 minutes, remove, cool, weigh again, replenish the lost mass with 65% methanol, shake well, filter, and take the filtrate, filter through a 0.45μm microporous membrane to obtain the final product.

[0064] 5. Preparation of reference solution

[0065] Accurately weigh appropriate amounts of isovitexin, indirubin, and tryptophan reference standards, dissolve them in methanol, and dilute them in 10 mL volumetric flasks to obtain mass concentrations of 0.365, 0.250, and 0.238 mg / mL, respectively. -1 Prepare single reference standard solutions at concentrations of (mg / mL), and accurately measure appropriate amounts of each single reference standard solution into 1mL volumetric flasks to obtain mixed reference standard stock solutions with mass concentrations of 0.1825, 0.0625, and 0.0595 mg / mL, respectively. -1 .

[0066] 6. Examination of linear relationships

[0067] Take an appropriate amount of the mixed reference standard stock solution and dilute it by 2, 4, 8, 16 and 32 times respectively. Perform the determination according to the above chromatographic conditions. Plot a standard curve with the concentration of the reference standard as the abscissa and the peak area as the ordinate. The results are shown in Table 1.

[0068] Table 1. Linear regression equations and regression coefficients of the main components of Isatis indigotica.

[0069] Element Linear equations Correlation coefficient (r) <![CDATA[Linear range (μg·mL -1 )]]> Isovitilione Y = 42040X + 121621 0.999 1 5.703～182.500 Indigo Red Y = 114308X - 71238 0.999 1 1.953～62.500 tryptophan Y = 39795X + 31260 0.999 8 1.850～74.000

[0070] 7. Determination of water-soluble extractives

[0071] Take Daqingye (Isatis leaf) Place approximately 10g of the prepared slices in a flat-bottomed flask, precisely add 15 times the amount of pure water (150mL), and soak until the leaves are fully steeped. The herbal extracts were chewed until disintegrated, then extracted by reflux for 15 minutes. After cooling, the extract was filtered. Ten times the volume of water (100 mL) was added, and the extract was refluxed for 10 minutes. After cooling, the extract was filtered again. The filtrates were combined, and 10 mL of the filtrate was accurately measured and placed in an evaporating dish (M1) dried to constant weight. The dish was then evaporated to dryness in a water bath and placed in an oven at 105°C for 3 hours. After drying, the dish was placed in a desiccator and cooled for 30 minutes. The mass was determined using a 0.01% balance (M2), and the extract yield was calculated. Water-soluble extract (%) = (M2 - M1) ÷ (10 × M) × V × 100%. Where M is the total mass of the herbal material, and V is the volume of the decoction.

[0072] 8. Subjective Weight Calculation in AHP: The Analytic Hierarchy Process (AHP) is a subjective weighting method that constructs hierarchical relationships based on the content of the experimental research and assigns weights to indicators according to their importance. (Note: The last sentence appears to be unrelated and likely refers to a different topic: "Daqingye" which translates to "Indigo Leaf".) The pressing process of the processed medicinal slices was evaluated using the contents of water-soluble extract, indirubin, isovitexin, and tryptophan as indicators. Indirubin, listed as an indicator component under the section on Isatis indigotica in the 2020 edition of the Chinese Pharmacopoeia, possesses anti-inflammatory, antibacterial, and immunomodulatory effects, and was ranked first. Tryptophan, with its antitumor, antibacterial, anti-inflammatory, antiviral, and cardiovascular protective effects, was ranked second. Isovitexin, with its antihypertensive and lipid-regulating pharmacological effects, was ranked third. Water-soluble extract, reflecting the overall content level of the medicinal slices, was ranked last. A priority matrix for pairwise comparison of the evaluation indicators was constructed using the consistent matrix method, and the weight coefficient (Wi) of each indicator was calculated. The results are shown in Table 3.

[0073] A consistency test is performed on the judgment matrix. The consistency ratio factor (CR) = consistency test factor (CI) / average random consistency index (RI). The larger the consistency ratio factor, the worse the consistency of the matrix. When the consistency ratio factor < 0.1, it indicates that the judgment matrix meets the consistency test, and the obtained weight coefficients are valid. The consistency ratio of this judgment matrix is ​​0.0454 < 0.1, that is, the weight coefficients are valid. The weight results are shown in Table 2.

[0074] Table 2 Judgment Matrix and AHP Weights of Each Indicator

[0075]

[0076] 9. Entropy weight method for calculating weights: The entropy weight method is a subjective weighting method that determines the weights of indicators based on the data measured for each indicator component. The original data of the indicator components are normalized according to formula (1); then the information entropy is calculated according to formulas (2) and (3), where m refers to the number of objects being evaluated and n refers to the number of evaluation indicators; finally, the objective weight Wj of each indicator component is calculated according to formula (4).

[0077]

[0078] 10. Determination of comprehensive weight and score: Combine the weight coefficients determined by the AHP method and the entropy weight method, use formula (5) to calculate the comprehensive weight, and combine the indicators of the evaluated object to calculate the comprehensive score using formula (6).

[0079]

[0080] Pressure, pressing time, drying temperature, and drying time were used as single-factor variables, and the comprehensive scoring formula obtained by the AHP-entropy weight method was used to comprehensively score the evaluation index of Daqingye granulated slices under different pressures, pressing times, drying temperatures, and drying times. The comprehensive score was used as the evaluation index for single-factor experiments, and the results are shown in Table 3.

[0081] The AHP-entropy weight method was used to comprehensively score the index components of Daqingye (Isatis tinctoria) slices under different pressures. The effects of pressures of 3 MPa, 4 MPa, and 5 MPa on the comprehensive score were investigated with fixed pressing time, drying temperature, and drying time. The results showed that the comprehensive score was highest at a pressure of 4 MPa.

[0082] The AHP-entropy weight method was used to comprehensively score the index components of Daqingye (Isatis tinctoria) slices under different pressing times. The effects of pressing times of 30s, 40s, 50s, 60s, 70s, 80s, and 90s on the comprehensive score were investigated with fixed pressure, drying temperature, and drying time. The results showed that the comprehensive score was highest when the pressing time was 60s.

[0083] The AHP-entropy weight method was used to comprehensively score the index components of Daqingye (Isatis tinctoria) slices at different drying temperatures. The effects of drying temperatures of 30℃, 40℃, 50℃, 60℃, 70℃, and 80℃ on the comprehensive score were investigated with fixed pressure, pressing time, and drying time. The results showed that the comprehensive score was highest at a drying temperature of 60℃.

[0084] The AHP-entropy weight method was used to comprehensively score the index components of Daqingye (Isatis tinctoria) slices under different drying times. The effects of drying times of 2.5h, 3h, 4h, and 5h on the comprehensive score were investigated with fixed pressure, pressing time, and drying temperature. The results showed that the comprehensive score was highest when the drying time was 4h.

[0085] Table 3. Overall scoring results of single-factor experiments

[0086]

[0087] Based on the comprehensive scoring results, the indicators for response surface optimization experiments were determined. The indicators were pressing time, drying temperature, and drying time, and the comprehensive score was used as the response value to conduct response surface optimization experiments to determine the optimal processing technology for Daqingye (Isatis indigotica) sliced ​​medicinal pieces.

[0088] Based on the results of the single-factor experiments above, and using Design Expert 13.0 software according to the central composite design principle, an optimization experiment was conducted with the factors affecting the pressing time, drying temperature, and drying time of Daqingye (Isatis tinctoria) slices as indicators, and the comprehensive score as the response value (Y). The optimal pressing process for Daqingye slices was determined, and the results are as follows: Figures 1-3 As shown, the quadratic multiple regression equation is obtained as Y = 92.34 + 3.02A + 0.7973B + 4.35C + 3.15AB - 3.29AC - 2.04BC - 3.20A. 2 -6.51B 2 -0.9684C 2P = 0.0194 < 0.05, indicating that the factor and the response value are significantly correlated. The lack-of-fit term P = 0.0643 > 0.05, indicating that the model is in line with the expected value. The comprehensive score results of the response surface are shown in Table 4.

[0089] Table 4. Response Surface Comprehensive Scoring Results

[0090]

[0091]

[0092] A three-dimensional response surface plot of processing factors and comprehensive score was drawn using Design Expert 13.0 software. The results are shown in [Figure Number]. Figures 1-3 The optimal pressing process for Daqingye (Isatis tinctoria) slices was determined to be: pressure 4 MPa, drying temperature 58.538℃, drying time 4.140 h, and pressing time 77.108 s. Based on actual production, the parameters were adjusted to be: for every 100 g of medicinal material, after moistening, cut into 5-7 mm pieces, press at 4 MPa for 60 s, and then dry at 60℃ for 4 h.

[0093] 11. Verification of process results

[0094] Based on the optimal results obtained from the response surface methodology and combined with actual operation, the parameters were adjusted as follows: for every 100g of medicinal material, after moistening, the material was cut into 5-7mm pieces, pressed at 4MPa for 60s, and then dried at 60℃ for 4h. Three parallel experiments were conducted for verification. The average comprehensive score obtained was 94.12%, and the RSD value was 1.27%. The results were close to the model predictions (see Table 5), indicating that the established model had good predictive ability and the process was stable and feasible.

[0095] Table 5. Verification Results of the Compression Process of Daqingye (Isatis indigotica) Slices

[0096]

[0097] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

Claims

1. An optimized method for pressing Isatis tinctoria leaf slices into medicinal slices, characterized in that, Includes the following steps: S1. After removing impurities from the dried Isatis tinctoria leaves, spray them with moisture. When they can be clumped together by hand but crumble when released, cut them into pieces. S2. The cutting range of Daqingye was analyzed by considering its formability, yield, and demolding difficulty. Based on the results, the cutting range of Daqingye was initially obtained, and the cutting range with good formability and the highest yield was identified as the optimal cutting range. S3. Based on the preliminary determination of the cutting range of Daqingye, the weight coefficients of each evaluation index are determined by AHP and entropy weight method, respectively, using indirubin, isovitexin, tryptophan, and water-soluble extract as comprehensive evaluation indicators. The comprehensive weight of each evaluation index is calculated by combining the weight coefficients determined by AHP and entropy weight method, and the comprehensive score calculation formula is obtained through the comprehensive weight result. S4. Using pressure, pressing time, drying temperature, and drying time as single-factor variables, the evaluation indicators of Daqingye under different pressures, pressing times, drying temperatures, and drying times are comprehensively scored using a comprehensive scoring formula. S5. Based on the comprehensive scoring results, determine the indicators for the response surface optimization experiment. Using pressing time, drying temperature, and drying time as indicators, and the comprehensive score as the response value, conduct the response surface optimization experiment to determine the optimal pressing process for Daqingye (Isatis indigotica) sliced ​​medicinal pieces.

2. The optimized pressing process of Daqingye (Isatis leaf) sliced ​​medicinal materials according to claim 1, characterized in that, In S2, the cutting range of the Daqingye (Isatis tinctoria) slices is 5-7 mm.

3. The optimized pressing process of Daqingye (Isatis leaf) sliced ​​medicinal materials according to claim 1, characterized in that, In S3, the method for calculating the weighting coefficients using AHP is as follows: based on the main active indicator components and extracts reflecting the overall level in Isatis indigotica leaves, the evaluation indicators are ranked as follows: indigo > tryptamine > isovitexin > water-soluble extracts.

4. The optimized pressing process of Daqingye (Isatis leaf) sliced ​​medicinal materials according to claim 1, characterized in that, In the S3 described above, the method for calculating the weight coefficients using the entropy weight method is as follows: the original data of the index components are normalized according to formula (1); then the information entropy is calculated according to formulas (2) and (3), where m refers to the number of objects being evaluated and n refers to the number of evaluation indicators; finally, the objective weight Wj of each index component is calculated according to formula (4). The meanings of each letter are as follows: d ij y: The standardized value of the i-th sample under the j-th indicator (the value after range standardization); ij : The original data of the j-th indicator of the i-th sample; y ijmax The maximum value of the j-th indicator among all samples; y ijmin The minimum value of the j-th indicator among all samples; e j The entropy value of the j-th index; m: Number of samples; p ij The standardized value of the j-th indicator in the i-th sample is the proportion of the total standardized values ​​of all samples of that indicator. w j The weight of the j-th indicator; n: The number of indicators.

5. The optimized pressing process of Daqingye (Isatis leaf) sliced ​​medicinal materials according to claim 1, characterized in that, In the S3 above, the method for determining the comprehensive weight and score is as follows: combine the weight coefficients determined by the AHP method and the entropy weight method, use formula (5) to calculate the comprehensive weight, and combine the indicators of the evaluated object to calculate the comprehensive score using formula (6). Among them, W i For the weights of each indicator determined by AHP, W j The weights of each index determined by the entropy weight method. β j The overall weight of the j-th indicator, OD ijP : The comprehensive score of the j-th indicator for the i-th sample.

6. The optimized pressing process of Daqingye (Isatis leaf) sliced ​​medicinal materials according to claim 1, characterized in that, In S5, the response surface optimization experiment, using Design-Expert 13.0 software and following the central composite design principle, yielded the quadratic multiple regression equation Y = 92.34 + 3.02A + 0.7973B + 4.35C + 3.15AB - 3.29AC - 2.04BC - 3.20A. 2 -6.51B 2 -0.9684C 2 Where A represents baking temperature, B represents baking time, and C represents pressing time.

7. The optimized pressing process of Daqingye (Isatis leaf) sliced ​​medicinal materials according to claim 1, characterized in that, In S5, the optimal pressing process for Daqingye (Isatis tinctoria) slices is as follows: pressure 4 MPa, drying temperature 58.538℃, drying time 4.140 h, and pressing time 77.108 s. Based on actual production, the parameters are adjusted to be: for every 100 g of medicinal material, after moistening, cut into 5-7 mm pieces, press at 4 MPa for 60 s, and then dry at 60℃ for 4 h.

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