Preparation process for extracting high-content chlorogenic acid from green coffee broken rice

Abstract

The invention relates to a preparation process for extracting high-content chlorogenic acid from green coffee broken rice. According to the process, a non-organic solvent method is adopted, the low-caffeine green coffee bean extract is prepared through the steps of raw material pretreatment, low-temperature ultrasonic enzymolysis extraction, column chromatography, concentration, spray drying and the like, and active ingredients of various caffeoylquinic acid substances such as chlorogenic acid are enriched. In the preparation process, a protective agent is used for avoiding attenuation of chlorogenic acid in heating and air, a resin gradient separation method is used for enriching chlorogenic acid to remove caffeine, and a UPLC technology is used for realizing simultaneous quantitative detection of various caffeoylquinic acid components. The preparation process has the advantages of no organic solvent residue, high effective component content, high separation efficiency, safety, environmental protection, and suitableness for large-scale production. The final product not only contains high chlorogenic acid and low caffeine, but also is rich in caffeoylquinic acid substances and other active ingredients, has better flavor than market products, and is lower in application difficulty in the food and beverage industry.

Description

Technical Field

[0001] The invention relates to the field of preparation of plant extracts, and in particular to a preparation process for extracting high-content chlorogenic acid from broken green coffee rice. Background Art

[0002] Green coffee broken rice is the powder made by grinding unroasted coffee beans. It is rich in minerals, proteins, fats, carbohydrates, vitamins and various biologically active ingredients. Green coffee bean extract is rich in active ingredients such as chlorogenic acid, polyphenols, natural caffeine, caffeoylquinic acid substances, etc. It has antibacterial, antiviral, blood pressure lowering, free radical scavenging and other effects. It is widely used in medicine, daily chemical industry and food industries. In traditional extraction processes, organic solvents such as methanol or chloroform are often used to extract coffee beans, which not only has residual risks, but also fails to effectively retain sensitive ingredients such as chlorogenic acid in coffee beans. Chlorogenic acid is an important phenolic acid compound with multiple biological activities. As an important natural antioxidant, chlorogenic acid has antibacterial, antiviral, lipid-lowering, and blood sugar-lowering functions, which is beneficial to human health. The active ingredient caffeine has an excitatory effect on the central nervous system through the cerebral cortex and can cheer up the spirit, but high caffeine can stimulate the central nervous system or heart, or stimulate digestive organs such as the gastrointestinal tract. People who are highly sensitive to these stimuli or have a high health consciousness tend to avoid them. The content ratio of each component in coffee bean extract, especially the effective content of caffeine and chlorogenic acid, has a major impact on the acidity and bitterness of the product. At present, environmentally friendly, safe and efficient extraction methods have attracted much attention, and there is great room for the development of technology to enhance the flavor of green coffee bean extract products. Summary of the invention

[0003] The purpose of the present invention is to provide a preparation process for extracting high-content chlorogenic acid from broken green coffee rice, which satisfies the high chlorogenic acid and low caffeine characteristics of green coffee bean extract and has excellent product flavor. The above technical objectives of the present invention are achieved through the following technical solutions: A preparation process for extracting high-content chlorogenic acid from broken green coffee rice, comprising the following steps: A. Raw material pretreatment: Select high-quality green coffee broken rice, pass it through a concentration device for preparing green coffee bean extract, dry it at 55-65°C to a moisture content of 8-10%, and obtain the treated green coffee broken rice raw material; B Extraction: Add green coffee rice raw materials into deionized water, add 0.05-0.5% VC, and extract at 60-95℃ for 6-10 hours; C. Extraction solution treatment: Cool the extract solution to room temperature, adjust the pH value to 2.0-5.0, and soak overnight; D column chromatography separation and enrichment: the extract is separated using a cation exchange resin, and the eluent is a 70-90% ethanol aqueous solution; E. Concentration and drying: The eluate is concentrated to 1 / 5-1 / 3 of the original volume by a rotary evaporator at 40-50°C, and the concentrate is spray-dried or freeze-dried to obtain chlorogenic acid powder; F Detection and analysis: Use the UPLC system to detect active ingredients such as caffeine, chlorogenic acid, 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, and 3.5-diCQA, and evaluate product flavor.

[0004] The present invention obtains high-purity green coffee bean extract by optimizing the processes of raw material processing, extraction, separation and enrichment, concentration and drying, and adopting UPLC technology for quality control. The process has the advantages of no organic solvent residue, protection of effective ingredients, high separation efficiency, low cost, safety and economy, and is suitable for large-scale production.

[0005] Preferably, in the raw material processing step A, high-quality unroasted green coffee broken rice is selected, and a raw material processing and high-efficiency concentration device for the preparation of green coffee bean extract is used to dry it in an oven at 60°C until the moisture content reaches 8%-10%, thereby obtaining the treated green coffee broken rice raw material. Among the active ingredients in coffee bean extracts, chlorogenic acid has a significant representative role. As an important natural antioxidant, chlorogenic acid has antibacterial, antiviral, lipid-lowering, and blood sugar-lowering functions, which are beneficial to human health. Compared with ordinary coffee beans of the same quality, green coffee beans retain chlorogenic acid to a greater extent and are a high-quality economic raw material source for chlorogenic acid extraction.

[0006] Preferably, in step B, a non-organic solvent method is used, water is used as the extraction solvent, and the solid-liquid ratio is 1:10-1:5, that is, for every 100g of green coffee broken rice powder, 1000-500mL of deionized water is added and soaked overnight, and then 0.05%-0.5% ascorbic acid (VC) is added, and extraction is performed 3 times at 60-95°C, for 3 hours, 3 hours, and 2 hours respectively, wherein the last 2 hours of extraction use ultrasonic assisted extraction method, ultrasonic power 200-400W, and constant temperature stirring is maintained during the extraction process to ensure full contact and uniform extraction. After the extraction is completed, solid impurities are removed by filtering through double-layer gauze. The water extraction method is used to extract the active ingredients in green coffee broken rice, avoiding the use of traditional organic solvents such as methanol, chloroform, etc., eliminating the risk of organic solvent residues, and ensuring the safety of the extract.

[0007] Furthermore, the protective agent added during the extraction process is 0.05% VC to prevent the degradation of active ingredients such as chlorogenic acid. VC has a strong antioxidant capacity and can stabilize the sensitive ingredient chlorogenic acid as a protective agent. After analyzing the data of the experimental groups without protective agents and with VC as a protective agent, it can be seen that the chlorogenic acid content of the product obtained in the group with VC added is significantly increased, and a peak value is obtained when 0.05% VC is added. A high content of VC will affect the flavor of the extract and increase the acidity of the final product; by adding an appropriate amount of VC protective agent, the content of the active ingredient chlorogenic acid can be effectively increased. This operation achieves the economic advantage of low cost and high purification, improves the lifting efficiency, and reduces waste.

[0008] Furthermore, the temperature during the extraction process was maintained at 85°C, and the extraction times were 3 hours, 3 hours, and 2 hours, respectively. The last 2 hours of extraction used ultrasonic-assisted extraction with an ultrasonic power of 300W. The UPLC test data results showed that the chlorogenic acid and caffeoylquinic acid contents extracted under ultrasonic-assisted conditions were both high, and the flavor was significantly improved, indicating that ultrasonic-assisted extraction is helpful for the dissolution of effective ingredients, and achieves separation and dispersion effects during ultrasonic oscillation, which has a beneficial effect on the adjustment of product acidity and bitterness. In terms of extraction temperature control, experimental data show that low temperatures will increase the bitterness of coffee bean extracts, and high temperatures will increase the yield of green coffee broken rice, but at the same time, it is also impossible to avoid the increase in the amount of interference from impurities dissolving. When the extraction temperature is 85°C, both the effective ingredients of the extract and the product flavor reach optimal values.

[0009] Preferably, in the C extract solution treatment step, the extract solution is cooled to room temperature, the pH value is adjusted to 2.0-5.0 using 1M hydrochloric acid, and then soaked overnight to ensure complete release of the components.

[0010] Furthermore, the extract treatment step uses 1M hydrochloric acid to adjust the pH value to 3.0 and then soak overnight. Under acidic conditions, the active ingredients in the coffee bean extract are analyzed. At a pH of 3.0, the active ingredients in the green coffee bean extract simultaneously achieve the effects of low caffeine and high chlorogenic acid. No research in the comparable documents shows the synergistic existence of the two in coffee bean extract.

[0011] Preferably, the extract is enriched using 250mL#40 cation exchange resin for separation and enrichment by D column chromatography. After resin adsorption, it is first washed with 5 times the column volume of deionized water, and then eluted with 3 times the column volume of 80% ethanol aqueous solution. The elution rate is controlled at a flow rate of 1-3mL / min. During the elution process, the resin method is used to separate and enrich chlorogenic acid, which not only improves the extraction efficiency during column chromatography, reduces product impurities, but also ensures the high purity of the final product. During the elution process, the elution effect can be controlled by adjusting the elution solvent and flow rate, and extracts with different chlorogenic acid contents can be produced according to different needs to meet the diverse needs on the market. Preferably, in E concentration and drying, the eluent is low-temperature concentrated to 1 / 5 to 1 / 3 of the original volume by a rotary evaporator at 40-50°C, and the vacuum degree is maintained at 0.08-0.10 MPa to avoid degradation of heat-sensitive components. The concentrated liquid is dried using a spray dryer, the feed temperature is 50-70°C, and the discharge temperature is 50-60°C. The moisture content of the dried powder product is less than 5%, and the coarse particles are removed by screening to obtain a uniform green coffee bean extract powder.

[0012] Furthermore, in the concentration and drying step, the eluent is low-temperature concentrated to 1 / 5 of the original volume by a rotary evaporator at 45°C to retain the activity of chlorogenic acid, and the concentrated liquid is dried using a spray dryer, the feed temperature is 70°C, the discharge temperature is 60°C, and the moisture content of the dried powder product is less than 5%. The process conditions of low-temperature concentration and spray drying effectively retain the activity of chlorogenic acid, improve production efficiency and extract quality, and make the finished product delicate and have a better flavor.

[0013] Preferably, ultra-high performance liquid chromatography (UPLC) is used in F detection and analysis to detect the final product to ensure the highest chlorogenic acid content in the product, and at the same time, the content of other caffeoylquinic acid substances such as caffeine, 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, 3.5-diCQA, etc. is detected to evaluate the flavor and active ingredient quality of the extract, and ensure the ratio of product ingredients and the stability of product quality.

[0014] Preferably, the green coffee bean extract product obtained by the preparation process for extracting high-content chlorogenic acid from green coffee broken rice has both high chlorogenic acid content and low caffeine content, rich content of caffeoylquinic acid substances such as 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, 3.5-diCQA, no organic solvent residue, low acidity and low bitterness, and good flavor. Among similar coffee bean extract products, there are few products extracted from green coffee broken rice as raw materials, and there is no clear description in relevant literature on green coffee bean extract products that meet the requirements of low caffeine and high chlorogenic acid. The present invention provides a preparation process for extracting high-content chlorogenic acid from green coffee broken rice on the basis of low caffeine in the product, so that the bitterness and acidity of the finished coffee bean extract reach the best taste.

[0015] Preferably, the present invention uses a concentration device for preparing green coffee bean extract in the raw material processing step A.

[0016] Preferably, the concentration device for preparing green coffee bean extract comprises an RO reverse osmosis membrane concentration box, a crushing barrel and a crushing and stirring device, the bottom wall of the crushing barrel is provided with a material guide pipe, the output end of the material guide pipe is connected to the RO reverse osmosis membrane concentration box, the side wall of the RO reverse osmosis membrane concentration box away from the crushing barrel is provided with a discharge pipe, the crushing device comprises a first motor, a crushing blade, a notch, a rotating shaft, a stirring shaft and a stirring rod, a screen is provided in the middle of the crushing box, the first motor is provided at the top of the crushing barrel, the output end of the first motor passes through the top wall of the crushing barrel and is provided with the rotating shaft, and the outer wall of the rotating shaft The crushing blade is installed in a ring shape, and the side wall of the crushing blade is provided with multiple groups of the notches. The bottom end of the rotating shaft is provided with the stirring shaft through a reduction motor, and the outer wall of the stirring shaft is provided with the stirring rod. A water tank is installed on one side of the top wall of the crushing barrel, and a water pipe is installed on the side wall of the water tank. The output end of the water pipe passes through the lower side wall of the crushing barrel and extends its inner cavity. A crushing box is installed on the end of the top wall of the crushing barrel away from the water tank, and a feed port is provided on the top of the crushing box. Two groups of crushing rollers are symmetrically installed in the crushing box, and the outer walls of the two groups of crushing rollers are provided with a plurality of protrusions, and a driving device is installed on the side wall of the crushing box.

[0017] In order to facilitate driving the two groups of crushing rollers to run simultaneously, the present invention is improved in that the driving device includes a driving wheel, a driven wheel, a conveyor belt and a second motor, one end of the two groups of crushing rollers passes through the side wall of the crushing box and is respectively provided with a driving wheel and the driven wheel, the driving wheel and the driven wheel are connected by the conveyor belt, and the second motor is installed at the end of the driving wheel away from the crushing box.

[0018] In order to protect the driving wheel and the driven wheel, the present invention is improved in that a protection box is installed on the outer wall of the crushing box.

[0019] In order to facilitate feeding, the present invention is improved in that a feeding hopper is installed on the feeding port.

[0020] In order to ensure the stable support of the crushing barrel, the present invention is improved in that support legs are installed at the four corners of the bottom end of the crushing barrel.

[0021] In order to ensure the stability and accuracy of the operation of the first motor and the second motor, the present invention is improved in that both the first motor and the second motor are servo motors.

[0022] In order to facilitate the control of the material guiding condition of the material guiding pipe, the present invention is improved in that a solenoid valve is installed on the material guiding pipe.

[0023] In order to facilitate the concentration of green coffee bean extract, the present invention is improved in that a plurality of filter membrane components are installed in the RO reverse osmosis membrane concentration box. In summary, the present invention has the following beneficial effects: 1. The present invention adopts a non-organic solvent method to extract the active ingredients in the broken green coffee rice, and uses a water extraction method to extract, avoiding the use of traditional organic solvents such as methanol, chloroform, etc., eliminating the risk of organic solvent residues, ensuring the safety of the extract, being green and environmentally friendly, complying with current environmental protection laws and regulations, reducing environmental pollution, and reducing the health risks to operators; 2. The present invention uses VC as a protective agent to protect active ingredients such as chlorogenic acid from degradation during the extraction process, thereby significantly increasing the content of chlorogenic acid in green coffee bean extract; the resin method is used to separate and enrich chlorogenic acid, which not only improves the extraction efficiency but also ensures the high purity of the final product; the application of UPLC technology enables the simultaneous detection and quantitative control of multiple caffeoylquinic acid substances in the product, ensuring the consistency and stability of product quality; 3. The present invention adopts the process conditions of low-temperature concentration and spray drying, which effectively retains the activity of chlorogenic acid and has high production efficiency. Compared with the traditional process, the present invention reduces equipment investment and production costs, and the preparation process is simple and easy, which is suitable for large-scale industrial production and provides an economical and affordable production method. 4. By optimizing the extraction process, the present invention can produce extracts with different chlorogenic acid contents according to different needs to meet the diverse needs in the market; the present invention provides a preparation process for extracting high-content chlorogenic acid from green coffee broken rice on the basis of low-caffeine products, and uses green coffee broken rice as raw materials to obtain a green coffee bean extract product that meets both low caffeine and high chlorogenic acid requirements, so that the bitterness and acidity of the finished coffee bean extract reach the best taste; 5. The high-content chlorogenic acid low-caffeine product produced by the present invention achieves a balance between the acidity and bitterness ratio unique to coffee beans, and the finished product has an excellent flavor; 6. The present invention applies a concentrating device for preparing green coffee bean extract, which uses a crushing roller to preliminarily crush green coffee beans through two groups of symmetrically installed crushing rollers. The convex design of the outer walls of these crushing rollers increases the contact area with the coffee beans, making the crushing process more efficient. The preliminary crushing can crush larger coffee beans into smaller particles, providing a good foundation for subsequent fine crushing, thereby ensuring that the final green coffee beans powder has a uniform particle size; the device, through the crushing and stirring device, the crushing blades in the crushing and stirring device are driven by the first motor to crush the preliminary powder. The crushed green coffee rice is finely ground to ensure the fineness and uniformity of the coffee rice powder. The slot design on the side wall of the crushing blade helps to reduce the resistance during the crushing process, making the crushing process smoother and further improving the crushing efficiency. Through fine crushing and stirring by the stirring rod, the active ingredients in the green coffee rice can be more fully released, thereby improving the quality and purity of the extract. The device, by setting up multiple sets of filter membrane components, can significantly increase the processing area by working in parallel with multiple sets of filter membrane components, thereby increasing the processing volume and concentration efficiency per unit time, which not only shortens the production cycle but also improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure is a schematic diagram of the overall structure of a concentration device for preparing green coffee bean extract; Figure 2 A schematic diagram of a half-cutaway three-dimensional structure of a grinding barrel of a concentration device for preparing green coffee bean extract; Figure 3 It is a schematic diagram of a half-cut three-dimensional structure of a RO reverse osmosis membrane concentration box of a concentration device for preparing green coffee bean extract; Figure 4 This is a schematic diagram of the half-cutaway three-dimensional structure of a grinding box of a concentration device for preparing green coffee bean extract.

[0025] In the figure: 1. RO reverse osmosis membrane concentration box; 2. crushing barrel; 3. material guide pipe; 4. discharge pipe; 5. first motor; 6. crushing blade; 7. notch; 8. rotating shaft; 9. stirring shaft; 10. stirring rod; 11. screen; 12. reduction motor; 13. water tank; 14. water pipe; 15. crushing box; 16. feed port; 17. crushing roller; 18. protrusion; 19. driving wheel; 20. driven wheel; 21. conveyor belt; 22. second motor; 23. protective box; 24. feed hopper; 25. support leg; 26. solenoid valve; 27. membrane assembly. DETAILED DESCRIPTION

[0026] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0027] Example 1: Preparation process of high chlorogenic acid and low caffeine A. Raw material processing: Select high-quality unroasted green coffee broken rice, pass it through a concentration device for preparing green coffee bean extract, and dry it in an oven at 60°C to a moisture content of 8-10%, thereby obtaining the processed green coffee broken rice raw material; Among them, Figure 1-4As shown, a concentration device for preparing green coffee bean extract comprises an RO reverse osmosis membrane concentration box 1, a crushing barrel 2 and a crushing and stirring device, wherein a guide pipe 3 is installed on the bottom wall of the crushing barrel 2, and the output end of the guide pipe 3 is connected to the RO reverse osmosis membrane concentration box 1, and a discharge pipe 4 is installed on the side wall of the end of the RO reverse osmosis membrane concentration box 1 away from the crushing barrel 2, and the crushing device comprises a first motor 5, a crushing blade 6, a notch 7, a rotating shaft 8, a stirring shaft 9 and a stirring rod 10, a screen 11 is installed in the middle of the crushing box 15, the first motor 5 is installed on the top of the crushing barrel 2, the output end of the first motor 5 penetrates the top wall of the crushing barrel 2 and is installed with the rotating shaft 8, and the outer wall of the rotating shaft 8 is annularly installed with the crushing The grinding blade 6 has a plurality of notches 7 on its side wall, the bottom end of the rotating shaft 8 is provided with the stirring shaft 9 via a reduction motor 12, the outer wall of the stirring shaft 9 is provided with the stirring rod 10, a water tank 13 is provided on one side of the top wall of the grinding barrel 2, a water pipe 14 is provided on the side wall of the water tank 13, the output end of the water pipe 14 passes through the lower side wall of the grinding barrel 2 and extends its inner cavity, a grinding box 15 is provided on the end of the top wall of the grinding barrel 2 away from the water tank 13, a feeding port 16 is provided on the top of the grinding box 15, two groups of grinding rollers 17 are symmetrically provided in the grinding box 15, a plurality of protrusions 18 are provided on the outer walls of the two groups of grinding rollers 17, a driving device is provided on the side wall of the grinding box 15, and the grinding rollers 17 are provided with a plurality of protrusions 18 on their outer walls. In the embodiment, when in use, the green coffee broken rice is fed into the grinding box 15 through the feed port 16 at the top of the grinding box 15. In the grinding box 15, two groups of symmetrically installed grinding rollers 17 start to perform preliminary grinding of the green coffee broken rice through the driving device. The outer walls of the two groups of grinding rollers 17 are both installed with a plurality of protrusions 18. These protrusions 18 can increase the contact area with the coffee broken rice and improve the grinding efficiency. As the grinding rollers 17 rotate, the green coffee broken rice is gradually broken into smaller particles. The green coffee broken rice particles that have been initially ground fall into the grinding barrel 2. Here, the first motor 5 drives the rotating shaft 8 to rotate, and the grinding blade 6 on the rotating shaft 8 further finely grinds the green coffee broken rice. At the same time, the notch 7 opened on the side wall of the grinding blade 6 helps to reduce the grinding resistance. The grinding barrel 2 is provided with a screen 11 which is installed in the middle of the grinding barrel 2 to filter out the larger particles which are not fully ground, so as to ensure that the green coffee rice powder entering the subsequent process has a uniform particle size. The water in the water tank 13 enters the grinding barrel 2 through the water pipe 14 and mixes with the ground coffee rice powder. The stirring shaft 9 at the bottom of the rotating shaft 8 rotates under the drive of the reduction motor 12. The stirring shaft 9 drives the stirring rod 10 to rotate at a uniform speed to stir the green coffee rice in the barrel to ensure uniform grinding. This process helps to soften the green coffee rice powder and prepare for the subsequent reverse osmosis membrane concentration. The mixed materials enter the RO reverse osmosis membrane concentration tank 1 through the guide pipe 3. Here, the water and soluble substances are separated by the filtering effect of the reverse osmosis membrane.The green coffee bean extract is concentrated, and the concentrated material can be discharged through the discharge pipe 4.

[0028] In actual use, it is further convenient to drive the two groups of crushing rollers 17 to run simultaneously. In this embodiment, the driving device includes a driving wheel 19, a driven wheel 20, a conveyor belt 21 and a second motor 22. One end of the two groups of crushing rollers 17 passes through the side wall of the crushing box 15 and is respectively provided with a driving wheel 19 and a driven wheel 20. The driving wheel 19 and the driven wheel 20 are connected by the conveyor belt 21. The second motor 22 is installed at the end of the driving wheel 19 away from the crushing box 15. The second motor 22 serves as a power source. The second motor 22 is started, and the power is transmitted to the conveyor belt 21 through the driving wheel 19, and then transmitted to the driven wheel 20 by the conveyor belt 21, so as to finally drive the two groups of crushing rollers 17 to rotate. This power transmission method is efficient and reliable, and can ensure that the crushing rollers 17 obtain sufficient power support when needed.

[0029] In actual use, the driving wheel 19 and the driven wheel 20 are further protected. In this embodiment, a protective box 23 is installed on the outer wall of the crushing box 15. The protective box 23 can effectively prevent the driving wheel 19 and the driven wheel 20 from being hit, scratched or corroded by external objects, thereby extending their service life and reducing downtime and maintenance costs caused by failures.

[0030] In actual use, in order to further facilitate feeding, in the present embodiment, a feed hopper 24 is installed on the feed port 16. The feed hopper 24 forms a certain space above the feed port 16, which acts as a buffer. This can slow down the speed at which materials enter, avoid impact and damage to the equipment caused by materials, and also help to stabilize the material flow in the production process.

[0031] In actual use, the support stability of the crushing barrel 2 is further ensured. In this embodiment, support legs 25 are installed at the four corners of the bottom end of the crushing barrel 2. The design of the support legs 25 enables the crushing barrel 2 to be firmly placed on the ground, reducing shaking or tilting caused by vibration or improper operation. This stability is essential for maintaining smooth operation of the machine during the crushing process, helps to reduce the impact of noise and vibration on the surrounding environment, and protects the internal components of the crushing barrel 2 from damage.

[0032] In actual use, the stability and accuracy of the operation of the first motor 5 and the second motor 22 are further guaranteed. In this embodiment, the first motor 5 and the second motor 22 are both servo motors. The servo motor can control the position, speed and torque with high precision. The servo motor adopts closed-loop control and has good stability. It can avoid problems such as stalling and vibration, thereby ensuring the stability and accuracy of the operation of the first motor 5 and the second motor 22.

[0033] In actual use, it is further convenient to control the material guiding condition of the material guiding pipe 3. In this embodiment, a solenoid valve 26 is installed on the material guiding pipe 3. The solenoid valve 26 can accurately control the flow, direction, pressure and other parameters of the medium through electrical signals, thereby realizing precise control of the material guiding process.

[0034] In actual use, it is further convenient to concentrate the green coffee bean extract. In this embodiment, multiple groups of filter membrane components 27 are installed in the RO reverse osmosis membrane concentration box 1. The parallel operation of multiple groups of filter membrane components 27 can significantly increase the processing area, thereby improving the processing volume and concentration efficiency per unit time. This is particularly important for large-scale production of green coffee bean extract, which can shorten the production cycle and improve production efficiency.

[0035] B extraction: the material-liquid ratio is 1:10, that is, for every 100g of green coffee rice raw material, add 1000mL of deionized water and soak overnight, then add 0.05% (0.05 ten thousandths) of VC as a protective agent, and perform extraction three times at 85°C, for 3 hours, 3 hours, and 2 hours respectively. The last 2 hours of extraction use ultrasonic assisted extraction method with ultrasonic power of 300W. During the extraction process, keep constant temperature and stirring to ensure full contact and uniform extraction. After the extraction, filter through double-layer gauze to remove solid impurities; C Extract treatment: The extract was cooled to room temperature, the pH value was adjusted to 3.0 with 1M hydrochloric acid, and then soaked overnight to ensure complete release of the components; D column chromatography separation and enrichment: The extract was enriched using 250 mL #40 cation exchange resin. After the resin was adsorbed, it was first washed with 5 column volumes of deionized water, and then eluted with 3 column volumes of 80% ethanol aqueous solution. The elution rate was controlled at 2 mL / min. E. Concentration and drying: The eluent is concentrated to 1 / 5 of the original volume at 45°C by a rotary evaporator, and the vacuum degree is maintained at 0.08 MPa to avoid degradation of heat-sensitive components. The concentrated liquid is dried by a spray dryer, and the feed temperature is 70°C and the discharge temperature is 60°C. The moisture content of the dried powder product is less than 5%, and the coarse particles are removed by screening to obtain a uniform green coffee bean extract powder; F. Testing and analysis: UPLC (ultra-high performance liquid chromatography) was used to test the final product to ensure that the product was low in caffeine and that the chlorogenic acid content in the product reached the highest level. At the same time, the content of other caffeoylquinic acid substances such as 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, and 3.5-diCQA was tested to evaluate the quality of the active ingredients and flavor of the extract; the flavor test method was: 10 reviewers were selected to score the product and its 1:100 aqueous solution in terms of acidity, bitterness, and overall flavor. The score was based on a 10-point system, with 6 points or more being qualified, 5-6 points being acceptable, and 7 points or more being excellent. The results are shown in Table 1.

[0036] Example 2: Extraction process with high solid-liquid ratio

[0037] In the extraction step B, the material-liquid ratio is 1:5, that is, for every 100 g of green coffee broken rice raw material, 500 mL of deionized water is added and soaked overnight; other conditions are the same as in Example 1.

[0038] Example 3: Extraction process of high VC

[0039] In step B, 0.5% (0.5%) VC was added as a protective agent; other conditions were the same as those in Example 1.

[0040] Example 4: Low temperature extraction process

[0041] In the extraction step B, 0.05% VC was added as a protective agent, and extraction was performed three times at 60° C. for 3 hours, 3 hours, and 2 hours respectively; other conditions were the same as in Example 1.

[0042] Example 5: High temperature extraction process

[0043] In the extraction step B, 0.05% VC was added as a protective agent, and extraction was performed three times at 95° C. for 3 hours, 3 hours, and 2 hours respectively; other conditions were the same as in Example 1.

[0044] Example 6: Extraction process without ultrasound assistance

[0045] In the extraction step B, 0.05% VC was added as a protective agent, and extraction was performed three times at 85° C. for 3 hours, 3 hours, and 2 hours respectively. The extraction process did not use ultrasonic assisted extraction; other conditions were the same as in Example 1.

[0046] Example 7: Low pH Extraction Solution Treatment Process

[0047] In the extract treatment step C, the extract is cooled to room temperature and the pH value is adjusted to 2.0 using 1 M hydrochloric acid; other conditions are the same as in Example 1.

[0048] Example 8: High pH Extraction Solution Treatment Process

[0049] In the extract treatment step C, the extract is cooled to room temperature and the pH value is adjusted to 5.0 using 1 M hydrochloric acid; other conditions are the same as in Example 1.

[0050] Comparative Example 1: Traditional Raw Material Processing and Extraction Method In the raw material processing A, high-quality unroasted green coffee broken rice is selected and directly dried in an oven at 60° C. until the moisture content reaches 9%. The dried green coffee broken rice is crushed into 60-mesh powder to obtain a green coffee broken rice raw material product; other conditions are the same as in Example 1.

[0051] Comparative Example 2: Organic solvent extraction method In the extraction step B, 80% methanol was used as the solvent, no protective agent was used, and the extraction conditions were 85° C. for 8 hours; other conditions were the same as in Example 1.

[0052] Comparative Example 3: Extraction without protective agent No protective agent was added in the B extraction step; other conditions were the same as in Example 1.

[0053] Comparative Example 4: Traditional Elution Process The extract was enriched by using a common ion exchange resin for separation and enrichment by D column chromatography. After adsorption by the resin, it was first washed with 5 column volumes of deionized water and then eluted with 3 column volumes of 80% ethanol aqueous solution. Other conditions were the same as those in Example 1.

[0054] The results show: The yield, caffeine, chlorogenic acid and caffeoylquinic acid content, bitterness, acidity and overall flavor of the green coffee bean extract products prepared in Examples 1-8 and Comparative Examples 1-4 were tested respectively. The results are shown in Table 1. Data analysis shows that: the yields of Examples 1-8 of the present invention are greater than those of Comparative Examples 1-4, indicating that the preparation process of the green coffee bean extract of the present invention has great advantages, and the production cost of products of the same quality is low; the caffeine content of Examples 1-8 is lower than that of Comparative Examples 1-4, and all are 1%-2%, which meets the quality requirements of low caffeine; the chlorogenic acid content of each product in Examples 1-8 is greater than that of Comparative Examples 1-4, indicating that the product purity of the preparation process of the present invention is high, the effective ingredients are high, and the quality requirements of high-content chlorogenic acid are met; the total content of caffeoylquinic acid substances such as 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, and 3.5-diCQA in Examples 1-8 is greater than that in Comparative Examples 1-4, indicating that the product of Examples 1-8 has a high content of active ingredients; the bitterness, acidity and overall flavor scores of the products of Examples 1-8 are higher than those of Comparative Examples 1-4, indicating that the products of Examples 1-8 have good flavor and good taste. Among them, Example 1 is the best example, which satisfies the following requirements: among all the examples, Example 1 has the highest yield of 28.79%; the lowest caffeine content of 1.27%; the highest chlorogenic acid content of 64.95%; the highest total content of caffeoylquinic acid substances of 58.71%; the product has an excellent flavor, with the best bitterness and acidity, and a good overall flavor.

[0055] Table 1 Comparison of index components and flavor evaluation of green coffee rice extract products prepared by different processes

Claims

1. A preparation process for extracting high-content chlorogenic acid from broken green coffee rice, characterized in that: The following steps are involved: A. Raw material pretreatment: Select high-quality green coffee broken rice, dry it at 55-65℃ to a moisture content of 8-10%, and obtain the treated green coffee broken rice raw material; B Extraction: Add the green coffee rice raw materials into deionized water, add 0.05-0.5% VC as a protective agent, and extract at 60-95℃ for 6-10 hours; C. Extraction solution treatment: Cool the extract solution to room temperature, adjust the pH value to 2.0-5.0, and soak overnight; D column chromatography separation and enrichment: the extract is separated using a cation exchange resin, and the eluent is a 70-90% ethanol aqueous solution; E. Concentration and drying: The eluate is concentrated to 1 / 5-1 / 3 of the original volume by a rotary evaporator at 40-50°C, and the concentrate is spray-dried or freeze-dried to obtain chlorogenic acid powder; F Detection and analysis: Use the UPLC system to detect the active ingredient content of caffeine, chlorogenic acid, 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, and 3.5-diCQA and evaluate the product flavor.

2. A preparation process for extracting high-content chlorogenic acid from broken green coffee rice according to claim 1, characterized in that: In the raw material processing step A, high-quality unroasted green coffee broken rice is selected, and is dried in an oven at 60° C. until the moisture content reaches 8%-10% by a concentration device for preparing green coffee bean extract, thereby obtaining the processed green coffee broken rice raw material.

3. A preparation process for extracting high-content chlorogenic acid from broken green coffee rice according to claim 1 or 2, characterized in that: A raw material processing step uses a concentration device for preparing green coffee bean extract, comprising an RO reverse osmosis membrane concentration box (1), a crushing barrel (2) and a crushing and stirring device, wherein a guide pipe (3) is installed on the bottom wall of the crushing barrel (2), and the output end of the guide pipe (3) is connected to the RO reverse osmosis membrane concentration box (1), and a discharge pipe (4) is installed on the side wall of the RO reverse osmosis membrane concentration box (1) away from the crushing barrel (2). The crushing device comprises a first motor (5), a crushing blade (6), a notch (7), a rotating shaft (8), a stirring shaft (9) and a stirring rod (10), a screen (11) is installed in the middle of the crushing box (15), the first motor (5) is installed at the top of the crushing barrel (2), the output end of the first motor (5) penetrates the top wall of the crushing barrel (2) and is installed with the rotating shaft (8), and the outer wall of the rotating shaft (8) is annularly installed. The crushing blade (6) is provided with a plurality of groups of notches (7) on the side wall of the crushing blade (6); the stirring shaft (9) is mounted on the bottom end of the rotating shaft (8) via a reduction motor (12); the stirring rod (10) is mounted on the outer wall of the stirring shaft (9); a water tank (13) is mounted on one side of the top wall of the crushing barrel (2); a water pipe (14) is mounted on the side wall of the water tank (13); the output end of the water pipe (14) penetrates the lower side wall of the crushing barrel (2) and extends into its inner cavity; a crushing box (15) is mounted on the end of the top wall of the crushing barrel (2) away from the water tank (13); a feed port (16) is mounted on the top of the crushing box (15); two groups of crushing rollers (17) are symmetrically mounted in the crushing box (15); a plurality of protrusions (18) are mounted on the outer walls of the two groups of crushing rollers (17); and a driving device is mounted on the side wall of the crushing box (15).

4. The process for extracting high-content chlorogenic acid from broken green coffee rice according to claim 1, characterized in that: In the B extraction step, a non-organic solvent method is used, and water is used as the extraction solvent. The solid-liquid ratio is 1:10-1:5, that is, for every 100g of green coffee broken rice raw material, 1000-500mL of deionized water is added and soaked overnight, and then 0.05%-0.5% ascorbic acid (VC) is added. The extraction is carried out three times at 60-95°C, and the time is 3 hours, 3 hours, and 2 hours respectively. The last 2 hours of extraction use ultrasonic assisted extraction method with ultrasonic power of 200-400W. Constant temperature stirring is maintained during the extraction process to ensure full contact and uniform extraction. After the extraction, solid impurities are removed by filtering through double-layer gauze.

5. A preparation process for extracting high-content chlorogenic acid from broken green coffee rice according to claims 1-3, characterized in that: The protective agent added during the extraction process is 0.05% VC to prevent the degradation of active ingredients such as chlorogenic acid; the temperature during the extraction process is maintained at 85°C, and the extraction times are 3 hours, 3 hours, and 2 hours, respectively, wherein the last 2 hours of extraction use ultrasonic-assisted extraction with an ultrasonic power of 300W.

6. The preparation process for extracting high-content chlorogenic acid from broken green coffee rice according to claim 1, characterized in that: In the C extract treatment step, the extract is cooled to room temperature, adjusted to a pH value of 2.0-5.0 using 1 M hydrochloric acid, and then soaked overnight to ensure complete release of the components.

7. The process for extracting high-content chlorogenic acid from broken green coffee rice according to claim 1, characterized in that: The extract was enriched using 250 mL #40 cation exchange resin for D column chromatography separation and enrichment. After resin adsorption, it was first washed with 5 column volumes of deionized water, and then eluted with 3 column volumes of 80% ethanol aqueous solution. The elution rate was controlled at a flow rate of 1-3 mL / min.

8. The process for extracting high-content chlorogenic acid from broken green coffee rice according to claim 1, characterized in that: E. In the concentration and drying process, the eluent is concentrated to 1 / 5 to 1 / 3 of the original volume at 40-50°C by a rotary evaporator, and the vacuum degree is maintained at 0.08-0.10 MPa to avoid degradation of heat-sensitive components. The concentrated liquid is dried using a spray dryer, and the feed temperature is 50-70°C and the discharge temperature is 50-60°C. The moisture content of the dried powder product is less than 5%, and the coarse particles are removed by screening to obtain a uniform green coffee bean extract powder.

9. The process for extracting high-content chlorogenic acid from broken green coffee rice according to claim 1, characterized in that: In F testing and analysis, ultra-high performance liquid chromatography (UPLC) is used to test the final product to ensure the highest chlorogenic acid content in the product. At the same time, the content of other caffeoylquinic acid substances such as caffeine, 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, and 3.5-diCQA are tested to evaluate the flavor and active ingredient quality of the extract.

10. The green coffee bean extract prepared by the process for extracting high-content chlorogenic acid from broken green coffee beans according to any one of claims 1 to 9, characterized in that: The product simultaneously meets the requirements of low caffeine and high chlorogenic acid, is rich in caffeoylquinic acid substances such as 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, and 3.5-diCQA, has no organic solvent residue, is low in acid and bitterness, and has a good flavor.

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