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

Abstract

The present invention relates to a preparation process for extracting high-content chlorogenic acid from broken green coffee beans. In the process, a non-organic solvent method is used, and by means of steps such as raw material pretreatment, low-temperature ultrasonic enzymatic extraction, column chromatography, concentration and spray drying, a low-caffeine green coffee bean extract is obtained, which is enriched with active ingredients such as chlorogenic acid and various caffeoylquinic acid substances. In the preparation process of the present invention, a protective agent is used for preventing the degradation of chlorogenic acid caused by heating and exposure to air, a resin step-gradient separation method is used to enrich chlorogenic acids and remove caffeine, and a UPLC technique is used to achieve the simultaneous quantitative detection of various caffeoylquinic acid components. The preparation process of the present invention has no organic solvent residue, a high content of active ingredients and high separation efficiency, is safe and environmentally friendly, and is suitable for large-scale production. The final product not only contains a high chlorogenic acid content and a low caffeine content, but is also rich in active ingredients such as caffeoylquinic acid substances. Compared to a market-available product, the final product has a superior flavor and less application difficulties in the food and beverage industry.

Description

Preparation process for extracting high content of chlorogenic acid from green coffee chaff TECHNICAL FIELD

[0001] The present application relates to the field of plant extract preparation, in particular to a preparation process for extracting high content of chlorogenic acid from green coffee chaff. BACKGROUND

[0002] Green coffee chaff is the ground powder of unroasted coffee beans, which contains rich minerals, proteins, fats, carbohydrates, vitamins and various bioactive ingredients. Green coffee extract is rich in active ingredients such as chlorogenic acid, polyphenol, natural caffeine, caffeoyl quinic acid and other active ingredients, and has antibacterial, antiviral, blood pressure lowering, free radical scavenging and other effects, and is widely used in medicine, daily chemical industry and food industry. In the traditional extraction process, organic solvents such as methanol or chloroform are often used to extract coffee beans, which not only has the risk of residue, but also cannot effectively retain the sensitive components 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, sugar-lowering and other functions, which is beneficial to human health. Active ingredient caffeine stimulates the central nervous system through the cerebral cortex, has an excitatory effect on the central nervous system, can invigorate the spirit, but high caffeine can stimulate the central nervous system or heart, or stimulate the digestive organs such as stomach and intestines, and people with strong sensitivity to these stimuli or people with high health consciousness have an aversion to it. The content ratio of each component in coffee extract, especially the effective content of caffeine and chlorogenic acid, has a major impact on product acidity and bitterness. At present, environmentally friendly, safe and efficient extraction methods are attracting attention, and there is great room for development in the improvement process of green coffee extract product flavor. SUMMARY

[0003] The purpose of the present application is to provide a preparation process for extracting high content of chlorogenic acid from green coffee chaff, which meets the characteristics of high chlorogenic acid and low caffeine of green coffee extract and has excellent product flavor. The above technical purpose of the present application is realized by the following technical scheme:

[0004] A preparation process for extracting high content of chlorogenic acid from green coffee chaff, comprising the following steps:

[0005] A raw material pretreatment: selecting high-quality green coffee chaff, drying to a moisture content of 8-10% at 55-65°C through a concentration device for green coffee extract preparation, to obtain treated green coffee chaff raw material;

[0006] B extraction: adding green coffee chaff raw material into deionized water and adding 0.05-0.5% VC, and extracting at 60-95°C for 6-10 hours;

[0007] C extract solution treatment: the extract solution is cooled to room temperature, and the pH value is adjusted to 2.0-5.0, and then soaked overnight;

[0008] D column chromatography separation and enrichment: the extract solution is separated using cation exchange resin, and the eluent is 70-90% ethanol aqueous solution;

[0009] E concentration and drying: the eluent is concentrated to 1 / 5-1 / 3 of the original volume at 40-50℃ by a rotary evaporator, and the concentrated solution is treated by spray drying or freeze drying to obtain chlorogenic acid powder;

[0010] F detection and analysis: UPLC system is used to detect active ingredients such as caffeine, chlorogenic acid, 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, 3.5-diCQA, and evaluate the flavor of the product.

[0011] The present application optimizes the processes of raw material treatment, extraction, separation and enrichment, concentration and drying, and adopts UPLC technology for quality control, to prepare green coffee bean extract with high purity. The process has the advantages of no organic solvent residue, protection of active ingredients, high separation efficiency, low cost, safety and economy, and is suitable for large-scale production.

[0012] As preferred, high-quality unroasted green coffee chaff is selected in the A raw material treatment step, which is dried to a water content of 8%-10% in an oven at 60℃ by a raw material treatment high-efficiency concentration device for green coffee bean extract preparation, to obtain the treated green coffee chaff raw material. Among the effective components of coffee bean extract, chlorogenic acid plays a significant representative role. As an important natural antioxidant, chlorogenic acid has functions of antibacterial, antiviral, lipid-lowering, sugar-lowering and the like, and is 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 an excellent and economical raw material source for chlorogenic acid extraction.

[0013] As preferred, non-organic solvent method is adopted in the B extraction step, and water is used as the extraction solvent, with a solid-liquid ratio of 1:10-1:5, i.e. 1000-500 mL of deionized water is added to 100 g of green coffee chaff powder, soaked overnight, and then 0.05%-0.5% of ascorbic acid (VC) is added, and extracted for 3 times at 60-95℃, with the time being 3 hours, 3 hours and 2 hours respectively, wherein the last 2 hours of extraction uses ultrasonic-assisted extraction method, with an ultrasonic power of 200-400 W, and constant temperature stirring is maintained during the extraction process to ensure sufficient contact and uniform extraction. After the extraction is completed, the solid impurities are removed by double-layer gauze filtration. The active ingredients in green coffee chaff are extracted by water extraction method, which avoids the use of traditional organic solvents such as methanol and chloroform, eliminates the risk of organic solvent residue, and ensures the safety of the extract.

[0014] Further, the protective agent added in the extraction process is 0.05% VC to prevent the degradation of active ingredients such as chlorogenic acid. VC has strong antioxidant capacity and can stabilize sensitive ingredients such as chlorogenic acid as a protective agent. After analyzing the data of the experimental group without protective agent and the experimental group with VC as protective agent, it is found that the chlorogenic acid content of the product obtained in the group with VC is significantly improved, and the peak value is obtained when the VC content is 0.05%. However, 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 improved. This operation realizes the economic advantage of low cost and high purification, improves the efficiency and reduces waste.

[0015] Further, the extraction temperature is kept at 85°C, and the extraction time is 3 hours, 3 hours, and 2 hours, respectively. The last 2 hours of extraction uses ultrasonic assisted extraction method with ultrasonic power of 300W. The UPLC detection data shows that the content of chlorogenic acid and caffeoyl quinic acid extracted under the condition of ultrasonic assistance is higher, and the flavor is obviously improved, which shows that ultrasonic assisted extraction is helpful for the dissolution of active ingredients, and the separation and dispersion effect is achieved in ultrasonic oscillation, which is beneficial to the adjustment of product acidity and bitterness. In terms of extraction temperature control, experimental data shows that low temperature will increase the bitterness of coffee bean extract, and high temperature will increase the yield of green coffee broken rice, but at the same time, it cannot avoid the increase of impurities dissolved and interfere with the amount. When the extraction temperature is 85°C, the effective components of the extract and the flavor of the product reach the best value.

[0016] As a preferred embodiment, the extraction liquid is cooled to room temperature in the extraction liquid treatment step, and then 1M hydrochloric acid is used to adjust the pH value to 2.0-5.0, and then soaked overnight to ensure complete release of the ingredients.

[0017] Further, the extraction liquid treatment step uses 1M hydrochloric acid to adjust the pH value to 3.0 and then soaks overnight. Under acidic conditions, the active ingredients in coffee bean extract are released. When the pH value is 3.0, the effective components of green coffee bean extract achieve the effect of low caffeine and high chlorogenic acid at the same time. There is no research in the same file that shows the synergistic effect of the two in coffee bean extract.

[0018] As preferred, the D column chromatography separation and enrichment of the extract is performed using 250 mL #40 cation exchange resin. After the resin is adsorbed, 5 times the column volume of deionized water is used for washing, followed by 3 times the column volume of 80% ethanol aqueous solution for elution, with an elution rate controlled at 1-3 mL / 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 impurities in the product, but also ensures 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 different chlorogenic acid content extracts can be produced according to different needs to meet the diversified needs of the market

[0019] As preferred, the E concentration and drying of the eluate is concentrated to 1 / 5 to 1 / 3 of the original volume at 40-50°C by a rotary evaporator, with a vacuum degree of 0.08-0.10 MPa to avoid degradation of heat-sensitive components. The concentrated liquid is dried using a spray dryer, with an inlet temperature of 50-70°C and an outlet temperature of 50-60°C. The moisture content of the dried powder product is less than 5%, and coarse particles are removed by screening to obtain uniform green coffee bean extract powder.

[0020] Further, the eluate in the concentration and drying step is concentrated to 1 / 5 of the original volume at 45°C by a rotary evaporator to retain the activity of chlorogenic acid. The concentrated liquid is dried using a spray dryer, with an inlet temperature of 70°C and an outlet temperature of 60°C. 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 ingredients fine and flavor better.

[0021] As preferred, in the F detection and analysis, ultra-high performance liquid chromatography (UPLC) is used to detect the final product to ensure that the chlorogenic acid content in the product reaches the highest, while detecting the content of other caffeoyl quinic acid substances such as caffeine, 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, 3.5-diCQA, etc. to evaluate the flavor and active ingredient quality of the extract, and ensure the stability of the product composition and product quality.

[0022] As preferred, the green coffee bean extract product prepared by the preparation process of extracting high content of chlorogenic acid from green coffee broken rice has high content of chlorogenic acid and low content of caffeine, 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 bitterness, good flavor. In the same kind of coffee bean extract product, the product extracted from green coffee broken rice as raw material, which meets the low caffeine and high chlorogenic acid at the same time, has no relevant literature information to clearly explain. The present application provides a preparation process of extracting high content of chlorogenic acid from green coffee broken rice on the basis of low caffeine product, so that the bitterness and acidity of the finished coffee bean extract product reach the best taste.

[0023] As preferred, the present application uses a concentration device for green coffee bean extract preparation in the A raw material processing step.

[0024] As preferred, the concentration device for green coffee bean extract preparation includes a RO reverse osmosis membrane concentration box, a crushing barrel and a crushing stirring device. A guide pipe is installed on the bottom wall of the crushing barrel. The output end of the guide pipe is connected with the RO reverse osmosis membrane concentration box. A discharge pipe is installed on the side wall of the end of the RO reverse osmosis membrane concentration box away from the crushing barrel. The crushing device includes a first motor, a crushing blade, a notch, a rotating shaft, a stirring shaft and a stirring rod. A screen is installed in the middle of the crushing box. The first motor is installed on the top end of the crushing barrel. The output end of the first motor penetrates the top wall of the crushing barrel and is installed with the rotating shaft. The outer wall of the rotating shaft is annularly installed with the crushing blade. The side wall of the crushing blade is provided with a plurality of notches. The bottom end of the rotating shaft is installed with the stirring shaft through a speed reducer. The outer wall of the stirring shaft is installed with the stirring rod. A water tank is installed on one side of the top wall of the crushing barrel. A water pipe is installed on the side wall of the water tank. The output end of the water pipe penetrates the lower side wall of the crushing barrel and extends in the inner cavity thereof. A crushing box is installed on the end of the top wall of the crushing barrel away from the water tank. An inlet is provided on the top end of the crushing box. Two groups of crushing rollers are symmetrically installed in the crushing box. The outer walls of the two groups of crushing rollers are each installed with a plurality of protrusions. A driving device is installed on the side wall of the crushing box.

[0025] In order to facilitate the driving of the two groups of crushing rollers to run at the same time, the utility model improves 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 penetrates the side wall of the crushing box and is respectively sleeved with a driving wheel and the driven wheel. The driving wheel and the driven wheel are connected through the conveyor belt. The driving wheel is installed with the second motor at the end away from the crushing box.

[0026] In order to protect the driving wheel and the driven wheel, the utility model improves, the outer wall of the smashing box is equipped with a protection box.

[0027] In order to facilitate feeding, the utility model improves, a feeding hopper is installed on the feeding port.

[0028] In order to guarantee the support stability of the smashing barrel, the utility model improves, support legs are installed at the bottom of the four corners of the smashing barrel.

[0029] In order to guarantee the stability and accuracy of the operation of the first motor and the second motor, the utility model improves, the first motor and the second motor are all servo motors.

[0030] In order to facilitate the control of the material guiding condition of the material guiding pipe, the utility model improves, an electromagnetic valve is installed on the material guiding pipe.

[0031] In order to facilitate the concentration of the green coffee bean extract, the utility model improves, a plurality of filter membrane assemblies are installed in the RO reverse osmosis membrane concentration box.

[0032] 1、The active ingredient in the green coffee bean extract is extracted by using a non-organic solvent method, and water extraction method is used to avoid the use of traditional organic solvents such as methanol and chloroform, eliminate the risk of organic solvent residue, ensure the safety of the extract, green and environmentally friendly, comply with current environmental protection regulations, reduce environmental pollution, and reduce the health risk to the operator.

[0033] 2、The application uses VC as a protective agent to protect the active ingredients such as chlorogenic acid from degradation during the extraction process, significantly improves the content of chlorogenic acid in the green coffee bean extract, and uses resin method to separate and enrich chlorogenic acid, which not only improves the extraction efficiency, but also ensures the high purity of the final product.

[0034] 3、The application uses low-temperature concentration and spray drying process conditions, effectively retains the activity of chlorogenic acid, and has high production efficiency; compared with the traditional process, the application reduces equipment investment and production cost, and the preparation process is simple and easy to operate, which is suitable for large-scale industrial production and provides an economical and practical production method.

[0035] 4. By optimizing the extraction process, the present application can produce extracts with different contents of chlorogenic acid according to different needs, meeting the diversified needs in the market; the present application provides a preparation process for extracting high-content chlorogenic acid from green coffee chaff on the basis of low-caffeine products, using green coffee chaff as raw material 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 product reach the best taste.

[0036] 5. The high-content chlorogenic acid low-caffeine product produced by the present application achieves a balance in the unique acidity and bitterness ratio of coffee beans, resulting in excellent flavor of the finished product.

[0037] 6. The present application applies a concentration device for green coffee extract preparation, which preliminarily crushes the green coffee chaff through two sets of symmetrically installed crushing rollers, the protrusions on the outer wall of the crushing rollers increase the contact area with the coffee chaff, making the crushing process more efficient, and the preliminary crushing can break larger coffee chaff particles into smaller ones, providing a good foundation for subsequent fine crushing, thereby ensuring that the green coffee chaff powder obtained finally has uniform particle size; the device, through the setting of the crushing and stirring device, the crushing blades in the crushing and stirring device finely crush the preliminarily crushed green coffee chaff under the drive of the first motor, ensuring the fineness and uniformity of the coffee chaff powder, the slot design on the side wall of the crushing blade helps to reduce the resistance in the crushing process, making the crushing process smoother and further improving the crushing efficiency, through fine crushing and stirring of the stirring rod, the effective components in the green coffee chaff can be more fully released, improving the quality and purity of the extract; the device, through the setting of multiple filter membrane assemblies, the parallel work of multiple filter membrane assemblies can significantly increase the processing area, thereby improving the processing capacity and concentration efficiency per unit time, not only shortening the production cycle, but also improving the production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a schematic diagram of the overall structure of the concentration device for green coffee extract preparation;

[0039] Figure 2 is a schematic diagram of the half-section structure of the crushing barrel of the concentration device for green coffee extract preparation;

[0040] Figure 3 is a schematic diagram of the half-section structure of the RO reverse osmosis membrane concentration box of the concentration device for green coffee extract preparation;

[0041] Figure 4 is a schematic diagram of the half-section structure of the crushing box of the concentration device for green coffee extract preparation.

[0042] In the figure: 1, RO reverse osmosis membrane concentration tank; 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, speed reducer motor; 13, water tank; 14, water pipe; 15, crushing box; 16, feed inlet; 17, crushing roller; 18, protrusion; 19, driving wheel; 20, driven wheel; 21, conveyor belt; 22, second motor; 23, protection box; 24, feed hopper; 25, supporting leg; 26, electromagnetic valve; 27, filter membrane assembly. DETAILED DESCRIPTION

[0043] The specific embodiments are only an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

[0044] Example 1: Preparation process of high chlorogenic acid and low caffeine

[0045] A raw material treatment: high-quality unroasted green coffee broken rice is selected, a concentration device for green coffee bean extract preparation is used, and the green coffee broken rice is dried in an oven at 60°C to a moisture content of 8-10% to obtain the treated green coffee broken rice raw material;

[0046] As shown in FIGS. 1-4, the concentration device for green coffee bean extract preparation includes a RO reverse osmosis membrane concentration box 1, a crushing barrel 2, and a crushing stirring device, a guide pipe 3 is installed on the bottom wall of the crushing barrel 2, the output end of the guide pipe 3 is connected with the RO reverse osmosis membrane concentration box 1, 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, the crushing device includes 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 barrel 2, the first motor 5 is installed on the top end of the crushing barrel 2, the output end of the first motor 5 penetrates through the top wall of the crushing barrel 2 and is installed with the rotating shaft 8, the outer wall of the rotating shaft 8 is annularly installed with the crushing blade 6, a plurality of notches 7 are formed on the side wall of the crushing blade 6, the bottom end of the rotating shaft 8 is installed with the stirring shaft 9 through a speed reducer 12, the outer wall of the stirring shaft 9 is installed with the stirring rod 10, a water tank 13 is installed on one side of the top wall of the crushing barrel 2, a water pipe 14 is installed on the side wall of the water tank 13, the output end of the water pipe 14 penetrates through the lower side wall of the crushing barrel 2 and extends into the inner cavity thereof, a crushing box 15 is installed on the top wall of the crushing barrel 2 away from the water tank 13, an inlet 16 is formed on the top end of the crushing box 15, two groups of crushing rollers 17 are symmetrically installed in the crushing box 15, the outer walls of the two groups of crushing rollers 17 are both installed with a plurality of protrusions 18, and a driving device is installed on the side wall of the crushing box 15, in use, green coffee grains are sent into the crushing box 15 through the inlet 16 on the top end of the crushing box 15, the two groups of crushing rollers 17 symmetrically installed in the crushing box 15 start to preliminarily crush the green coffee grains through the driving device, the outer walls of the two groups of crushing rollers 17 are both installed with a plurality of protrusions 18, the protrusions 18 can increase the contact area with the coffee grains and improve the crushing efficiency, with the rotation of the crushing rollers 17, the green coffee grains are gradually broken into smaller particles, the preliminarily crushed green coffee grain particles fall into the crushing barrel 2, here, the first motor 5 drives the rotating shaft 8 to rotate, the crushing blade 6 on the rotating shaft 8 further finely crushes the green coffee grains, at the same time, the notches 7 formed on the side wall of the crushing blade 6 help to reduce the crushing resistance and improve the crushing efficiency, the screen 11 installed in the middle of the crushing barrel 2 can filter out the larger particles that are not sufficiently crushed, so as to ensure that the green coffee grain powder entering the subsequent process has a uniform particle size, the water in the water tank 13 enters the crushing barrel 2 through the water pipe 14 and is mixed with the crushed coffee grain powder, the stirring shaft 9 at the bottom end of the rotating shaft 8 rotates under the drive of the speed reducer 12, the stirring shaft 9 drives the stirring rod 10 to rotate at a uniform speed, stirs the green coffee grains in the barrel, and ensures uniform crushing, this process helps to soften the green coffee grain powder and prepares for the subsequent reverse osmosis membrane concentration, the mixed material enters the RO reverse osmosis membrane concentration box 1 through the guide pipe 3, here, the water and soluble substances are separated by the filtering effect of the reverse osmosis membrane,Concentration of green coffee bean extract is achieved, and the concentrated material can be finally discharged through the discharge pipe 4.

[0047] In actual use, further facilitate the drive two sets of crushing roller 17 run simultaneously, in this embodiment, the drive device includes driving wheel 19, driven wheel 20, conveyor belt 21 and second motor 22, two sets of the crushing roller 17 one end through the side wall of the crushing box 15 is set with driving wheel 19 and the driven wheel 20 respectively, the driving wheel 19 and the driven wheel 20 through the conveyor belt 21 between the connection, the driving wheel 19 away from the crushing box 15 one end is installed with the second motor 22, second motor 22 as power source, start second motor 22, through the driving wheel 19 power transmission to the conveyor belt 21, again by the conveyor belt 21 to the driven wheel 20, finally drive two sets of crushing roller 17 rotation, this power transmission mode is efficient and reliable, can ensure that the crushing roller 17 when needed to obtain sufficient power support.

[0048] In actual use, further to the driving wheel 19 and the driven wheel 20 protection, in this embodiment, the outer wall of the crushing box 15 is installed with the protection box 23, protection box 23 can effectively prevent the driving wheel 19 and the driven wheel 20 from being impacted, scratched or corroded by external objects, thereby prolonging its service life, reducing downtime and maintenance costs caused by failure.

[0049] In actual use, further facilitate feeding, in this embodiment, the feeding port 16 is installed with feeding hopper 24, feeding hopper 24 forms a certain space above the feeding port 16, plays a buffering role, which can slow down the speed of material entering, avoid the impact and damage of material to the equipment, at the same time, also helps to stabilize the material flow in the production process.

[0050] In actual use, further ensure the support stability of the crushing barrel 2, in this embodiment, the bottom corner of the crushing barrel 2 is installed with support leg 25, the design of support leg 25 makes the crushing barrel 2 can be stably placed on the ground, reduces the shaking or tilting caused by vibration or improper operation, this stability is very important for keeping the machine running smoothly during the crushing process, helps to reduce the influence of noise and vibration on the surrounding environment, at the same time, protects the internal parts of the crushing barrel 2 from damage.

[0051] In actual use, further ensure the stability and accuracy of the first motor 5 and the second motor 22 operation, in this embodiment, the first motor 5 and the second motor 22 are both servo motors, servo motor can control position, speed and torque with very high precision, servo motor adopts closed loop control, has good stability, can avoid stall, vibration and other problems, ensure the stability and accuracy of the first motor 5 and the second motor 22 operation.

[0052] In actual use, it is further convenient to control the material guiding of the material guiding pipe 3. In this embodiment, an electromagnetic valve 26 is installed on the material guiding pipe 3. The electromagnetic valve 26 can accurately control the flow, direction, pressure and other parameters of the medium through an electrical signal, so as to realize accurate control of the material guiding process.

[0053] In actual use, it is further convenient to concentrate the green coffee bean extract. In this embodiment, a plurality of filter membrane assemblies 27 are installed in the RO reverse osmosis membrane concentration tank 1. The parallel operation of the plurality of filter membrane assemblies 27 can significantly increase the processing area, thereby improving the processing capacity and concentration efficiency per unit time. This is particularly important for large-scale production of green coffee bean extract, can shorten the production cycle, and improve the production efficiency.

[0054] B extraction: the material liquid ratio is 1:10, that is, 1000 mL of deionized water is added to 100 g of green coffee broken rice raw material after soaking overnight, 0.05% (50 parts per million) of VC is added as a protective agent, and 3 times of extraction is carried out at 85°C, the time is 3 hours, 3 hours and 2 hours respectively, and the last 2 hours of extraction uses ultrasonic assisted extraction method, the ultrasonic power is 300W, the extraction process is kept constant temperature stirring to ensure sufficient contact and uniform extraction, after the extraction is completed, the solid impurities are removed by double-layer gauze filtration;

[0055] C treatment of extraction liquid: the extraction liquid is cooled to room temperature, and then 1M hydrochloric acid is used to adjust the pH value to 3.0, and then soaked overnight to ensure complete release of ingredients;

[0056] D column chromatography separation and enrichment: the extraction liquid is enriched using 250 mL #40 cation exchange resin, after the resin adsorption, first use 5 times the column volume of deionized water to clean, then use 3 times the column volume of 80% ethanol aqueous solution to elute, and the elution speed is controlled at 2 mL / min;

[0057] E concentration and drying: the eluate is concentrated to 1 / 5 of the original volume by a rotary evaporator at 45°C, and the vacuum degree is kept at 0.08 MPa to avoid degradation of heat-sensitive components. The concentrated liquid is dried by a spray dryer, the feeding temperature is 70°C, and the discharging temperature is 60°C. The moisture content of the dried powder product is less than 5%, and coarse particles are removed by screening to obtain uniform green coffee bean extract powder;

[0058] F Detection and analysis: UPLC (ultra performance liquid chromatography) is used to detect the final product to ensure that the product is low in caffeine and the content of chlorogenic acid in the product reaches the highest, while the contents of other caffeoylquinic acid substances such as 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, 3.5-diCQA, etc. are detected to evaluate the quality of active ingredients and flavor of the extract; the flavor test method is: 10 evaluators are selected to evaluate and score the product and its 1:100 aqueous solution from acidity, bitterness, and overall flavor, with a score of 10 points, 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.

[0059] Example 2: Extraction process with high material-to-liquid ratio

[0060] B In the extraction step, the material-to-liquid ratio is 1:5, that is, 100 g of green coffee broken rice raw material is soaked overnight with 500 mL of deionized water; other conditions are the same as in Example 1.

[0061] Example 3: Extraction process with high VC

[0062] B In the extraction step, 0.5% (5 thousandths) of VC is added as a protective agent; other conditions are the same as in Example 1.

[0063] Example 4: Extraction process with low temperature extraction

[0064] B In the extraction step, 0.05% of VC is added as a protective agent, and 3 extractions are carried out at 60°C, with times of 3 hours, 3 hours, and 2 hours, respectively; other conditions are the same as in Example 1.

[0065] Example 5: Extraction process with high temperature extraction

[0066] B In the extraction step, 0.05% of VC is added as a protective agent, and 3 extractions are carried out at 95°C, with times of 3 hours, 3 hours, and 2 hours, respectively; other conditions are the same as in Example 1.

[0067] Example 6: Extraction process without ultrasonic assistance

[0068] B In the extraction step, 0.05% of VC is added as a protective agent, and 3 extractions are carried out at 85°C, with times of 3 hours, 3 hours, and 2 hours, respectively, without using ultrasonic assistance in the extraction process; other conditions are the same as in Example 1.

[0069] Example 7: Extraction liquid treatment process with low pH

[0070] C In the extraction liquid treatment step, the extraction liquid is cooled to room temperature, and 1M hydrochloric acid is used to adjust the pH value to 2.0; other conditions are the same as in Example 1.

[0071] Example 8: High pH extract treatment process

[0072] C The extract was cooled to room temperature in the extract treatment step, and the pH was adjusted to 5.0 using 1 M hydrochloric acid; other conditions were the same as in Example 1.

[0073] Comparative Example 1: Conventional raw material treatment extraction method

[0074] A High-quality unroasted green coffee chaff was selected for the raw material treatment, and was directly dried in an oven at 60°C until the water content reached 9%. The dried green coffee chaff was ground into a powder of 60 mesh to obtain a green coffee chaff raw material product; other conditions were the same as in Example 1.

[0075] Comparative Example 2: Organic solvent extraction method

[0076] B 80% methanol was used as the solvent in the extraction step without a protective agent, and the extraction conditions were 85°C for 8 hours; other conditions were the same as in Example 1.

[0077] Comparative Example 3: No protective agent extraction method

[0078] B No protective agent was added in the extraction step; other conditions were the same as in Example 1.

[0079] Comparative Example 4: Conventional elution process

[0080] D The extract was enriched using ordinary ion exchange resin in the column chromatography separation and enrichment, and after the resin was adsorbed, it was 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; other conditions were the same as in Example 1.

[0081] The results showed that:

[0082] The product yield, content of caffeine, chlorogenic acid and caffeoylquinic acid, and bitterness, acidity and overall flavor of the green coffee bean extract products prepared in Examples 1-8 and Comparative Examples 1-4 were tested, and the results are shown in Table 1. Data analysis showed that the yield of Examples 1-8 was higher than that of Comparative Examples 1-4, indicating that the green coffee bean extract preparation process of the present application has great advantages, and the production cost of the same quality product is low; the content of caffeine in Examples 1-8 is lower than that of Comparative Examples 1-4, and is within 1%-2%, meeting the quality requirements of low caffeine; the content of chlorogenic acid in Examples 1-8 is higher than that of Comparative Examples 1-4, indicating that the product prepared by the preparation process of the present application has high purity, good quality and high content of effective components, meeting the quality requirements of high content of chlorogenic acid; the total content of 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, 3.5-diCQA and other caffeoylquinic acid substances in Examples 1-8 is higher than that of Comparative Examples 1-4, indicating that the content of active ingredients of the product of Examples 1-8 is high; 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 embodiment, which meets: among all the examples, the yield of Example 1 is the highest, which is 28.79%; the content of caffeine is the lowest, which is 1.27%; the content of chlorogenic acid is the highest, which is 64.95%; the total content of caffeoylquinic acid substances is the highest, which is 58.71%; the product flavor is excellent, and the bitterness and acidity are the best taste, and the overall flavor is good.

[0083] Table 1 Comparison of index components and flavor evaluation of green coffee bean extract products prepared by different processes

[0084] ​

Claims

1. A process for the preparation of high content of chlorogenic acids extracted from green coffee grains, characterized by, The method comprises the following steps: A raw material pretreatment: select high-quality green coffee broken rice, dry at 55-65℃ to a moisture content of 8-10%, to obtain the pretreated green coffee broken rice raw material; B extraction: add the green coffee broken rice raw material to deionized water, and add 0.05-0.5% VC as a protective agent, extract at 60-95℃ for 6-10 hours; C treatment of the extract: cool the extract to room temperature, adjust the pH to 2.0-5.0, and soak overnight; D column chromatography separation and enrichment: separate the extract using a cation exchange resin, and the eluent is 70-90% ethanol aqueous solution; E concentration and drying: concentrate the eluent to 1 / 5-1 / 3 of the original volume at 40-50℃ using a rotary evaporator, and spray dry or freeze dry the concentrated solution to obtain a chlorogenic acid powder; F detection and analysis: use an UPLC system to detect the contents of caffeine, chlorogenic acid, 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, 3.5-diCQA active ingredients and evaluate the flavor of the product.

2. The process for the preparation of high content chlorogenic acids from green coffee cherry according to claim 1, characterized in that, A raw material treatment step: select high-quality unroasted green coffee broken rice, dry in a 60℃ oven to a moisture content of 8%-10% using a concentration device for green coffee bean extract preparation, to obtain the pretreated green coffee broken rice raw material.

3. The process for the preparation of high content of chlorogenic acids from green coffee cherry according to claim 1 or 2, characterized in that, A raw material processing step uses a concentration device for green coffee bean extract preparation, including a RO reverse osmosis membrane concentration tank (1), a crushing barrel (2) and a crushing stirring device, the bottom wall of the crushing barrel (2) is provided with a material guide pipe (3), the output end of the material guide pipe (3) is connected with the RO reverse osmosis membrane concentration tank (1), the end wall of the RO reverse osmosis membrane concentration tank (1) away from the crushing barrel (2) is provided with a discharge pipe (4), the crushing device includes 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 top end of the crushing barrel (2) is provided with the first motor (5), the output end of the first motor (5) penetrates the top wall of the crushing barrel (2) and is provided with the rotating shaft (8), the outer wall of the rotating shaft (8) is annularly provided with the crushing blade (6), a plurality of notches (7) are formed in the side wall of the crushing blade (6), the bottom end of the rotating shaft (8) is provided with the stirring shaft (9) through a speed reducer (12), the outer wall of the stirring shaft (9) is provided with the stirring rod (10), a water tank (13) is installed on one side of the top wall of the crushing barrel (2), a water pipe (14) is installed 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 the inner cavity thereof, a crushing box (15) is installed on the top wall of the crushing barrel (2) away from the water tank (13), an inlet (16) is formed in the top end of the crushing box (15), two groups of crushing rollers (17) are symmetrically installed in the crushing box (15), a plurality of protrusions (18) are installed on the outer wall of each of the two groups of crushing rollers (17), and a driving device is installed on the side wall of the crushing box (15).

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

5. The process as claimed in claims 1-3, wherein the process for the extraction of high content of chlorogenic acid from green coffee cherries is characterized by, 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 time is 3 hours, 3 hours and 2 hours respectively. The last 2 hours of extraction uses ultrasonic assisted extraction method, with ultrasonic power of 300W.

6. The process for the preparation of high content chlorogenic acids from green coffee cherry according to claim 1, characterized in that, In the extraction liquid treatment step, the extraction liquid 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.

7. The process as claimed in claim 1, wherein the process for the extraction of high content chlorogenic acid from green coffee cherries is characterized by, D column chromatography separation and enrichment in the extraction of 250 mL # 40 cation exchange resin for enrichment, resin adsorption, first with 5 times the column volume of deionized water washing, followed by 3 times the column volume of 80% ethanol elution, elution rate control at 1-3 mL / min flow rate.

8. The process for the preparation of high content chlorogenic acids from green coffee cherry according to claim 1, characterized in that, E concentration and drying in the eluate by rotary evaporator at 40-50 ℃ low temperature concentration to the original volume of 1 / 5 to 1 / 3, vacuum degree is maintained at 0.08-0.10 MPa, to avoid the degradation of heat sensitive ingredients, the liquid after concentration using spray dryer drying, feed temperature is 50-70 ℃, the discharge temperature is 50-60 ℃, the moisture content of the dried powder product is less than 5%, and through the screening to remove coarse particles, get uniform green coffee extract powder.

9. The process for the preparation of high content chlorogenic acids extracted from green coffee grains according to claim 1, characterized in that, F detection and analysis of the use of ultra performance liquid chromatography (UPLC) for final product testing, to ensure that the product in the content of chlorogenic acid to the highest, while detecting caffeine, 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, 3.5-diCQA and other caffeoyl quinic acid content, evaluation of the flavor and active ingredient quality of the extract.

10. A green coffee extract prepared according to the process of any one of claims 1 to 9, characterized in that, The product meets the low caffeine and high chlorogenic acid, 3-CQA, 5-CQA, 4-CQA, 5-FQA, 3.4-diCQA, 3.5-diCQA, 3.5-diCQA and other caffeoyl quinic acid content rich, no organic solvent residue, low acid and low bitter, good flavor.

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