Method for clean and efficient large-scale preparation of blueberry leaf extract

Abstract

The invention discloses a method for clean and efficient large-scale preparation of a blueberry leaf extract. The method comprises the following steps: (1) pretreatment; (2) cell wall breaking: adopting one or more wall breaking modes of steam explosion wall breaking, microwave freeze thawing wall breaking and wet fine grinding wall breaking; (3) extracting, roughly filtering, concentrating and precisely filtering; (4) separating, purifying, concentrating and powdering; (5) post-treatment; and (6) clean production. The safe, clean, intelligent and industrial production of the blueberry leaf extract is achieved, the total polyphenol content of the product is larger than or equal to 35%, and zero emission of three wastes is achieved in the production process.

Description

Technical Field

[0001] The invention relates to the technical field of biological extraction, and in particular to a method for clean, efficient and large-scale preparation of a blueberry leaf extract. Background Art

[0002] Blueberries are highly praised for their unique flavor, rich in polyphenols, and various health benefits. As the area of ​​blueberry cultivation continues to expand, the number of branches and leaves produced by pruning is also increasing each year. As a byproduct of the blueberry cultivation process, blueberry leaves have a high content of polyphenols. Studies have shown that blueberry leaf polyphenols have antioxidant, antiviral, anti-tumor, blood pressure lowering, blood lipid lowering and diabetes treatment functions. Therefore, it is of great application value to establish a clean and efficient large-scale production process of blueberry leaf extract using blueberry leaves as raw materials.

[0003] However, in current production, blueberry leaves are mostly treated as waste and not effectively utilized, resulting in a huge waste of resources. Therefore, in-depth research on the extraction and purification process of blueberry leaves is of positive significance for the development of new food raw materials, health foods and natural medicines of blueberry leaves and the comprehensive utilization of blueberry leaf resources. Summary of the invention

[0004] Blueberry leaf extract is rich in polyphenols. The present invention provides a method for preparing blueberry leaf extract in a clean, efficient and large-scale manner. The extract has high polyphenol content, high purity, few impurities, high extraction efficiency, low cost and little environmental pollution, and is particularly suitable for large-scale production.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for clean, efficient and large-scale preparation of blueberry leaf extract, comprising the following steps:

[0006] (1) Pretreatment: fresh blueberry leaves are picked and washed by bubbling, drained, air-dried, quick-frozen, and stored in a frozen state;

[0007] (2) Cell wall disruption:

[0008] a) Steam explosion: placing the frozen blueberry leaves obtained in step (1) into the material bin of a steam explosion reactor, pressurizing with steam, maintaining the pressure, and releasing the pressure to complete the wall breaking;

[0009] b) Microwave freeze-thaw cell wall breaking: the frozen blueberry leaves obtained in step (1) are placed in a tunnel-type microwave oven and heated by microwaves for 6 to 15 minutes until the center temperature of the blueberry leaves at the tunnel outlet is 50±10° C., and cell wall breaking is completed;

[0010] c) Wet grinding and cell wall breaking: the frozen blueberry leaves obtained in step (1) are added with hot water and mixed, and pumped into a vertical precision wet grinding machine for 4 to 8 minutes to complete cell wall breaking;

[0011] One or more of the above are used to break the cell wall;

[0012] (3) Extraction, coarse filtration, concentration, and precision filtration: The cell-wall-broken blueberry leaves obtained in step (2) are successively subjected to acid water or acidified edible alcohol extraction, filtration, concentration, and precision filtration to obtain an extract concentrate and a filter residue, respectively;

[0013] (4) separation, purification, concentration, and powder making: the extracted concentrated solution obtained in step (3) is pumped into an adsorption resin chromatographic column at a constant flow rate for adsorption, and the column is first washed with water at room temperature for desorption, and then washed with aqueous edible alcohol for desorption; the edible alcohol washing column effluent is then concentrated at a constant temperature and reduced pressure; the concentrated solution is spray-dried, and sterilization and powder making are performed simultaneously, so as to achieve one-step completion of sterilization and powder making;

[0014] (5) Post-processing: the blueberry leaf extract powder obtained in step (4) is batch mixed, crushed, and sieved, and then the metal foreign matter is removed by an iron remover, and finally the product is packaged by an automatic powder packaging machine;

[0015] (6) Clean production: The filter residue obtained in step (3) is recycled as a natural fertilizer for organic blueberry cultivation or a raw material for pet food; the alcohol fraction produced by evaporation in the concentration process of steps (3) and (4) is distilled in a high-speed centrifugal distillation machine and then put into the next batch of production for recycling.

[0016] Preferably, in step (1), the blueberry leaves are washed and dried continuously by a bubbling washing + draining + air drying machine; the quick freezing is performed by a tunnel quick freezer or a quick freezing warehouse, the quick freezing temperature is -40 to 35°C, and the quick freezing speed is 1.0 ton of blueberry leaves / hour; the blueberry leaves are stored in a freezer, the storage temperature is -20 to -18°C, and the storage humidity is 85% to 95%.

[0017] Preferably, the steam explosion wall breaking in step (2) a) adopts a steam explosion machine, the explosion steam pressure is 1.0 MPa (180-190° C.), the pressure holding time is 90 s, and the wall breaking rate is close to 100%.

[0018] Preferably, the microwave freeze-thaw wall breaking in step (2) b) adopts a tunnel type microwave machine, the microwave power is 2.5-5Kw / section, the microwave frequency is 2300-2600MHz, the conveying speed of blueberry leaves is 300-1000Kg / h, the total stroke is 6-15min, the central temperature of the blueberry leaves at the tunnel outlet is 50±10°C, and the wall breaking rate is 90%.

[0019] Preferably, the wet fine grinding and wall breaking in step (2) c) adopts a vertical precision wet grinding and cutting machine, the material-liquid ratio of blueberry leaves to hot water is 1:2 (W / V), the rotating disk speed is 6000-9000 rpm / min, the grinding time is 4-8 min, and the wall breaking rate is 80%.

[0020] The above three wall breaking methods can ensure continuous feeding and discharging, with a large processing capacity, and realize industrial-scale production.

[0021] Preferably, the extraction solvent in step (3) is water containing 0.5-3% glacial acetic acid or edible alcohol containing 0.5-3% glacial acetic acid and having an ethanol volume fraction of 50-80%, the extraction material-liquid ratio is 1:10-1:40 (W / V), the hot reflux extraction temperature is 40-60° C., and the extraction time is 3-9 hours;

[0022] Use a rotary drum filter for coarse filtration with a filtration mesh of 50 to 70 meshes;

[0023] A centrifugal scraper film evaporator or an external circulation single-effect or multiple-effect evaporator is used for constant temperature and reduced pressure concentration, the concentration temperature is 40 to 60° C., the vacuum degree is -0.04 to -0.095 MPa, and the concentration end point is when the ethanol concentration of the concentrated liquid is ≤1% (W / V) under online monitoring;

[0024] Use open-flow or dark-flow plate and frame filter press for precision filtration, use P450 filter cloth, and the filtration pressure is 0.4-0.6MPa.

[0025] Preferably, the adsorption resin used for separation and purification in step (4) is a gel resin or macroporous resin having a single functional group of carboxyl, ester or hydroxyl, or a bifunctional group of hydroxyl and ester, hydroxyl and amide or ester and amide; the diameter-to-height ratio of the chromatographic column is 1:6-1:7, the polyphenol loading ratio of the adsorption resin filled is 9.0-25.0 mg / g, and the flow linear velocity of the loading liquid is 2-9 cm / min; the column is desorbed by washing with 2-6 column volumes of water at room temperature, and then the column is washed with 4-12 column volumes of edible alcohol at room temperature with an ethanol volume fraction of 20-80%; the flow linear velocity of the water and alcohol desorption washing liquids is 2-9 cm / min;

[0026] The concentration in step (4) is carried out by constant temperature and reduced pressure concentration using a centrifugal scraper thin film evaporator, the concentration temperature is 55 to 65°C, the vacuum degree is -0.04 to -0.095MPa, and the concentration end point is when the volume fraction of ethanol in the concentrate reaches ≤1% (V / V); for the centrifugal scraper thin film evaporator, the material is centrifugally distributed to form a thin film liquid layer on the inner wall of the evaporator, the heat transfer coefficient is high, and low-temperature rapid evaporation is achieved. At the same time, the scraper in the evaporator rotates to scrape the wall, avoiding the loss of high-viscosity material from gelatinization, thereby increasing the yield of blueberry leaf extract and ensuring that the product's ethanol residue, bulk density and other indicators are qualified;

[0027] In the step (4), the powder is prepared by spray drying, the spray drying inlet air temperature is 140-180°C, the exhaust air temperature is 80-95°C, the exhaust air is fully opened, and the inlet air volume is adjusted so that the pressure in the spray tower is -50 to -100 Pa.

[0028] Preferably, when desorption is carried out by washing the column at room temperature in step (4), the effluent from the washing column is discharged into a sewage treatment station and used as nutrients for microorganisms.

[0029] Furthermore, in the step (4), the volume of the water washing column is 5 times the column volume; the desorption liquid is edible alcohol with an ethanol volume fraction of 70%, and the volume of the desorption liquid is 6 times the column volume; the desorption is carried out at a flow linear velocity of 4.4 cm / min, and the total polyphenol content of the obtained blueberry leaf extract powder is ≥35%.

[0030] Preferably, the batch mixing in step (5) is carried out using a square cone IBC barrel tumbling mixer with a tumbling frequency of 50 Hz and a mixing time of 3 hours;

[0031] Use ultra-fine pulverizer for crushing, close the air valve to discharge;

[0032] Ultrasonic vibrating screen is used for screening;

[0033] The iron remover adopts a four-layer drawer-type iron remover with a magnetic force of each magnetic rod ≥ 10,000 Gauss;

[0034] The product packaging adopts servo motor spiral feeding quantitative packaging machine with a quantitative accuracy of +0.5 grams;

[0035] In step (5), the material transmission is carried out in a closed pipeline by a vacuum feeder to achieve dust-free operation. Finally, a blueberry leaf extract powder product is obtained, and the total polyphenol content is ≥35%.

[0036] By adopting the above method, leaf waste generated by blueberry planting and pruning is used to produce nutritious food raw materials rich in polyphenols, the aqueous alcohol generated in the production process is recycled, the filter residue solid waste is recycled, and the powder production process is dust-free. This is a clean production that fully utilizes resources, saves energy, and is environmentally friendly.

[0037] The present invention effectively utilizes the byproducts generated during the blueberry planting process, namely blueberry leaves, thereby reducing resource waste; the blueberry leaf extract of the present invention has high polyphenol purity, and the total polyphenol content is ≥35%, which greatly retains its functional activity and improves its utilization value. In addition, the present invention realizes the large-scale production of blueberry leaf extract, which has promotion value. DETAILED DESCRIPTION

[0038] Example 1

[0039] Step (1) Pretreatment:

[0040] Fresh blueberry leaves are picked, washed by bubbling, drained, air-dried, and quick-frozen at a temperature of -40 to -35°C and a speed of 1.0 ton of blueberry leaves per hour. They are then stored in a freezer at a temperature of -20 to -18°C and a humidity of 85% to 95%.

[0041] Step (2) Steam explosion:

[0042] 125 kg of frozen blueberry leaves (artificially grown Blue Beauty No. 1 blueberry leaves, with a polyphenol content of 12.84%) were put into the material bin of the steam explosion reactor. The explosion steam pressure of the reactor was set to 1.0 MPa (180-190° C.), the pressure was maintained for 90 seconds, and the pressure was released to complete cell wall disruption.

[0043] Step (3) extraction, coarse filtration, concentration, and fine filtration:

[0044] The blueberry leaves after cell wall breaking are put into a continuous countercurrent extraction unit, and the blueberry leaves after cell wall breaking are extracted by a continuous countercurrent extraction process and 1% acid water. Among them, the acid water is an aqueous solution of glacial acetic acid, the feed rate is 18Kg / h, the liquid feed rate is 475L / h, the extraction temperature is 40°C, and the time is 9h. Then, a 60-mesh rotary filter is used for online filtration, and the filter residue is squeezed and collected for standby use. The filtrate is pumped into a single-effect three-stage scraper concentrator for concentration, the concentration temperature is 40-60°C, the vacuum degree is -0.04-0.095Mpa, and the ethanol concentration of the concentrated solution is monitored online until ≤1% (W / V) is the concentration end point. Subsequently, the concentrated solution is pumped into an open flow or dark flow plate frame, and the plate frame filter press is used for impurity removal, using a P450 filter cloth and a filtration pressure of 0.4-0.6MPa.

[0045] Step (4) separation, purification, concentration and powder making:

[0046] The extracted concentrated solution was pumped into a LYD-801 food industry adsorption resin (resin bed layer is 40cm diameter x 240cm high, each column resin amount is 196kg) for adsorption, and the flow line velocity of the leaf residue treatment liquid is 6.6cm / min. Then, 5 column volumes of pure water with a pH of 5.3 were used to wash the column at a flow line velocity of 4.4cm / min, and the washing column liquid was collected at the same time. Subsequently, 6 column volumes of alcohol with an ethanol volume fraction of 70% were used for desorption at a flow line velocity of 4.4cm / min. Then, a centrifugal scraper film evaporator was used for constant temperature and reduced pressure concentration, the concentration temperature was 55-65°C, the vacuum degree was -0.04-0.095MPa, and the concentration end point was when the ethanol volume fraction of the concentrated solution was ≤1% (V / V) by online monitoring, and the alcohol was recovered at the same time. Next, spray drying was performed, with an inlet air temperature of 140 to 180° C., an exhaust air temperature of 80 to 95° C., and the exhaust air was fully opened, and the inlet air volume was adjusted so that the pressure in the spray tower was -50 to -100 Pa, thereby obtaining a blueberry leaf extract powder, wherein the blueberry leaf extract powder weighed 12.62 kg and had a total polyphenol content of 38.15%.

[0047] Step (5) post-processing:

[0048] The blueberry leaf extract powder obtained in step (4) is put into a square cone IBC barrel tumbling mixer for batch mixing, with a tumbling frequency of 50 Hz and a mixing time of 3 hours; it is crushed by an ultrafine grinder, sieved by an ultrasonic vibrating screen, and then the metal foreign matter is removed by a four-layer drawer-type iron remover with a magnetic force of ≥10,000 Gauss for each magnetic rod, and finally a servo motor spiral feeding quantitative packaging machine is used with a quantitative accuracy of +0.5 grams. During this period, the transmission of materials in each step is carried out by a vacuum feeder pipeline closed operation to achieve dust-free operation, and finally 12.39 kg of blueberry leaf extract powder product is obtained.

[0049] Step (6) Clean production:

[0050] The filter residue obtained in step (3) is recycled as a natural fertilizer for organic blueberry cultivation or a raw material for pet food; the alcohol fraction produced by evaporation in the concentration process of steps (3) and (4) is distilled in a high-speed centrifugal distillation machine and then recycled into the next batch of production processes.

[0051] Example 2

[0052] Step (1) Pretreatment:

[0053] Fresh blueberry leaves are picked, washed by bubbling, drained, air-dried, and quick-frozen at a temperature of -40 to -35°C and a speed of 1.0 ton of blueberry leaves per hour. They are then stored in a freezer at a temperature of -20 to -18°C and a humidity of 85% to 95%.

[0054] (2) Microwave freeze-thaw cell breaking:

[0055] 125kg of frozen blueberry leaves (artificially grown Blue Beauty No. 1 blueberry leaves, with a polyphenol content of 11.28%) were spread on a conveyor belt using a vibrating distributor and transported at a speed of 300kg / h, and then subjected to microwave treatment using a three-section nine-section tunnel type microwave unit, with a total travel time of 15min. The microwave frequency of the tunnel type microwave unit was 2450MHz, the first section was a preheating section, with a microwave power of 2.5kW / section, the second section was a thawing section, with a microwave power of 3.5kW / section, the third section was a heating section, with a microwave power of 5kW / section, and only the preheating section and the thawing section were subjected to synchronous dehumidification treatment by a dehumidifying fan. The central temperature of the blueberry leaves at the tunnel exit was 55°C, and thawed blueberry leaves were obtained.

[0056] (3) Extraction, coarse filtration, concentration, and fine filtration:

[0057] The blueberry leaves after cell wall breaking are put into a continuous countercurrent extraction unit, and the blueberry leaves after cell wall breaking are extracted by a continuous countercurrent extraction process and 1% acid water. Among them, the acid water is an aqueous solution of glacial acetic acid, the feed rate is 18Kg / h, the liquid feed rate is 475L / h, the extraction temperature is 40°C, and the time is 9h. Then, a 60-mesh rotary filter is used for online filtration, and the filter residue is squeezed and collected for standby use. The filtrate is pumped into a single-effect three-stage scraper concentrator for concentration, the concentration temperature is 40-60°C, the vacuum degree is -0.04-0.095Mpa, and the ethanol concentration of the concentrated solution is monitored online until ≤1% (W / V) is the concentration end point. Subsequently, the concentrated solution is pumped into an open flow or dark flow plate frame, and the plate frame filter press is used for impurity removal, using a P450 filter cloth and a filtration pressure of 0.4-0.6MPa.

[0058] Step (4) separation, purification, concentration and powder making:

[0059] The extracted concentrated solution was pumped into a LYD-801 food industry adsorption resin (resin bed layer is 40cm diameter x 240cm high, each column resin amount is 196kg) for adsorption, and the flow line velocity of the leaf residue treatment liquid is 6.6cm / min. Then, 5 column volumes of pure water with a pH of 5.3 were used to wash the column at a flow line velocity of 4.4cm / min, and the washing column liquid was collected at the same time. Subsequently, 6 column volumes of alcohol with an ethanol volume fraction of 70% were used for desorption at a flow line velocity of 4.4cm / min. Then, a centrifugal scraper film evaporator was used for constant temperature and reduced pressure concentration, the concentration temperature was 55-65°C, the vacuum degree was -0.04-0.095MPa, and the concentration end point was when the ethanol volume fraction of the concentrated solution was ≤1% (V / V) by online monitoring, and the alcohol was recovered at the same time. Next, spray drying was performed, with an inlet air temperature of 140 to 180° C., an exhaust air temperature of 80 to 95° C., and the exhaust air was fully opened. The inlet air volume was adjusted so that the pressure in the spray tower was -50 to -100 Pa, and a blueberry leaf extract powder was obtained. The blueberry leaf extract powder weighed 9.39 kg and had a total polyphenol content of 37.51%.

[0060] Step (5) post-processing:

[0061] The blueberry leaf extract powder obtained in step (4) is put into a square cone IBC barrel tumbling mixer for batch mixing, with a tumbling frequency of 50 Hz and a mixing time of 3 hours; it is crushed by an ultrafine grinder, sieved by an ultrasonic vibrating screen, and then the metal foreign matter is removed by a four-layer drawer-type iron remover with a magnetic force of ≥10,000 Gauss per magnetic rod, and finally a servo motor spiral feeding quantitative packaging machine is used with a quantitative accuracy of +0.5 grams. During this period, the transmission of materials in each step is carried out by a vacuum feeder pipeline closed operation to achieve dust-free operation, and finally 9.15 kg of blueberry leaf extract powder product is obtained.

[0062] Step (6) Clean production:

[0063] The filter residue obtained in step (3) is recycled as a natural fertilizer for organic blueberry cultivation or a raw material for pet food; the alcohol fraction produced by evaporation in the concentration process of steps (3) and (4) is distilled in a high-speed centrifugal distillation machine and then recycled into the next batch of production processes.

[0064] Example 3

[0065] Step (1) Pretreatment:

[0066] Fresh blueberry leaves are picked, washed by bubbling, drained, air-dried, and quick-frozen at a temperature of -40 to -35°C and a speed of 1.0 ton of blueberry leaves per hour. They are then stored in a freezer at a temperature of -20 to -18°C and a humidity of 85% to 95%.

[0067] Step (2) wet grinding and wall breaking:

[0068] 125 kg of frozen blueberry leaves (artificially grown Blue Beauty No. 1 blueberry leaves, with a polyphenol content of 12.31%) were added to 60°C hot water and mixed by high-speed shearing and stirring, and then pumped into a vertical precision wet grinder for cyclic grinding and cutting to complete cell wall breaking. The material-liquid ratio of blueberry leaves to hot water was 1:2 (W / V), the rotating disk speed was 6000-9000 rpm / min, the grinding time was 4-8 minutes, and the cell wall breaking was completed.

[0069] Step (3) extraction, coarse filtration, concentration, and fine filtration:

[0070] The blueberry leaves after cell wall breaking are put into a continuous countercurrent extraction unit, and the blueberry leaves after cell wall breaking are extracted by a continuous countercurrent extraction process and 1% acid water. Among them, the acid water is an aqueous solution of glacial acetic acid, the feed rate is 18Kg / h, the liquid feed rate is 475L / h, the extraction temperature is 40°C, and the time is 9h. Then, a 60-mesh rotary filter is used for online filtration, and the filter residue is squeezed and collected for standby use. The filtrate is pumped into a single-effect three-stage scraper concentrator for concentration, the concentration temperature is 40-60°C, the vacuum degree is -0.04-0.095Mpa, and the ethanol concentration of the concentrated solution is monitored online until ≤1% (W / V) is the concentration end point. Subsequently, the concentrated solution is pumped into an open flow or dark flow plate frame, and the plate frame filter press is used for impurity removal, using a P450 filter cloth and a filtration pressure of 0.4-0.6MPa.

[0071] Step (4) separation, purification, concentration and powder making:

[0072] The extracted concentrated solution was pumped into a LYD-801 food industry adsorption resin (resin bed layer is 40cm diameter x 240cm high, each column resin amount is 196kg) for adsorption, and the flow line velocity of the leaf residue treatment liquid is 6.6cm / min. Then, 5 column volumes of pure water with a pH of 5.3 were used to wash the column at a flow line velocity of 4.4cm / min, and the washing column liquid was collected at the same time. Subsequently, 6 column volumes of alcohol with an ethanol volume fraction of 70% were used for desorption at a flow line velocity of 4.4cm / min. Then, a centrifugal scraper film evaporator was used for constant temperature and reduced pressure concentration, the concentration temperature was 55-65°C, the vacuum degree was -0.04-0.095MPa, and the concentration end point was when the ethanol volume fraction of the concentrated solution was ≤1% (V / V) by online monitoring, and the alcohol was recovered at the same time. Next, spray drying was performed, with an inlet air temperature of 140 to 180° C., an exhaust air temperature of 80 to 95° C., and the exhaust air was fully opened. The inlet air volume was adjusted so that the pressure in the spray tower was -50 to -100 Pa, and a blueberry leaf extract powder was obtained. The blueberry leaf extract powder weighed 10.23 kg and had a total polyphenol content of 37.62%.

[0073] Step (5) post-processing:

[0074] The blueberry leaf extract powder obtained in step (4) is put into a square cone IBC barrel tumbling mixer for batch mixing, with a tumbling frequency of 50 Hz and a mixing time of 3 hours; it is crushed by an ultrafine grinder, sieved by an ultrasonic vibrating screen, and then the metal foreign matter is removed by a four-layer drawer-type iron remover with a magnetic force of ≥10,000 Gauss per magnetic rod, and finally a servo motor spiral feeding quantitative packaging machine is used with a quantitative accuracy of +0.5 grams. During this period, the transmission of materials in each step is carried out by a vacuum feeder pipeline closed operation to achieve dust-free operation, and finally 9.91 kg of blueberry leaf extract powder product is obtained.

[0075] Step (6) Clean production:

[0076] The filter residue obtained in step (3) is recycled as a natural fertilizer for organic blueberry cultivation or a raw material for pet food; the alcohol fraction produced by evaporation in the concentration process of steps (3) and (4) is distilled in a high-speed centrifugal distillation machine and then recycled into the next batch of production processes.

[0077] Example 4

[0078] Step (1) Pretreatment:

[0079] Fresh blueberry leaves are picked, washed by bubbling, drained, air-dried, and quick-frozen at a temperature of -40 to -35°C and a speed of 1.0 ton of blueberry leaves per hour. They are then stored in a freezer at a temperature of -20 to -18°C and a humidity of 85% to 95%.

[0080] Step (2) Steam explosion:

[0081] 125 kg of frozen blueberry leaves (artificially grown Blue Beauty No. 1 blueberry leaves, with a polyphenol content of 13.12%) were put into the material bin of the steam explosion reactor. The explosion steam pressure of the reactor was set to 1.0 MPa (180-190° C.), the pressure was maintained for 90 seconds, and the pressure was released to complete cell wall disruption.

[0082] Step (3) extraction, coarse filtration, concentration, and fine filtration:

[0083] The blueberry leaves after cell wall breaking are put into a continuous countercurrent extraction unit, and the blueberry leaves after cell wall breaking are extracted by a continuous countercurrent extraction process and 1% acid water. Among them, the acid water is an aqueous solution of glacial acetic acid, the feed rate is 18Kg / h, the liquid feed rate is 475L / h, the extraction temperature is 40°C, and the time is 9h. Then, a 60-mesh rotary filter is used for online filtration, and the filter residue is squeezed and collected for standby use. The filtrate is pumped into a single-effect three-stage scraper concentrator for concentration, the concentration temperature is 40-60°C, the vacuum degree is -0.04-0.095Mpa, and the ethanol concentration of the concentrated solution is monitored online until ≤1% (W / V) is the concentration end point. Subsequently, the concentrated solution is pumped into an open flow or dark flow plate frame, and the plate frame filter press is used for impurity removal, using a P450 filter cloth and a filtration pressure of 0.4-0.6MPa.

[0084] Step (4) separation, purification, concentration and powder making:

[0085] The extracted concentrated solution was pumped into a LYD-801 food industry adsorption resin (resin bed layer is 40cm diameter x 240cm high, each column resin amount is 196kg) for adsorption, and the flow line velocity of the leaf residue treatment liquid is 6.6cm / min. Then, 5 column volumes of pure water with a pH of 5.3 were used to wash the column at a flow line velocity of 4.4cm / min, and the washing column liquid was collected at the same time. Subsequently, 6 column volumes of alcohol with an ethanol volume fraction of 70% were used for desorption at a flow line velocity of 4.4cm / min. Then, a centrifugal scraper film evaporator was used for constant temperature and reduced pressure concentration, the concentration temperature was 55-65°C, the vacuum degree was -0.04-0.095MPa, and the concentration end point was when the ethanol volume fraction of the concentrated solution was ≤1% (V / V) by online monitoring, and the alcohol was recovered at the same time. Next, spray drying was performed, with an inlet air temperature of 140 to 180° C., an exhaust air temperature of 80 to 95° C., and the exhaust air was fully opened. The inlet air volume was adjusted so that the pressure in the spray tower was -50 to -100 Pa, and a blueberry leaf extract powder was obtained. The blueberry leaf extract powder weighed 19.12 kg and had a total polyphenol content of 42.89%.

[0086] Step (5) post-processing:

[0087] The blueberry leaf extract powder obtained in step (4) is put into a square cone IBC barrel tumbling mixer for batch mixing, with a tumbling frequency of 50 Hz and a mixing time of 3 hours; it is crushed by an ultrafine grinder, sieved by an ultrasonic vibrating screen, and then the metal foreign matter is removed by a four-layer drawer-type iron remover with a magnetic force of ≥10,000 Gauss for each magnetic rod, and finally a servo motor spiral feeding quantitative packaging machine is used with a quantitative accuracy of +0.5 grams. During this period, the transmission of materials in each step is carried out by a vacuum feeder pipeline closed operation to achieve dust-free operation, and finally 18.93 kg of blueberry leaf extract powder product is obtained.

[0088] Step (6) Clean production:

[0089] The filter residue obtained in step (3) is recycled as a natural fertilizer for organic blueberry cultivation or a raw material for pet food; the alcohol fraction produced by evaporation in the concentration process of steps (3) and (4) is distilled in a high-speed centrifugal distillation machine and then recycled into the next batch of production processes.

[0090] Example 5

[0091] Step (1) Pretreatment:

[0092] Fresh blueberry leaves are picked, washed by bubbling, drained, air-dried, and quick-frozen at a temperature of -40 to -35°C and a speed of 1.0 ton of blueberry leaves per hour. They are then stored in a freezer at a temperature of -20 to -18°C and a humidity of 85% to 95%.

[0093] Step (2) Microwave freeze-thaw cell breaking:

[0094] 125kg of frozen blueberry leaves (artificially grown Blue Beauty No. 1 blueberry leaves, with a polyphenol content of 12.52%) were spread on a conveyor belt using a vibrating distributor and transported at a speed of 300kg / h, and then subjected to microwave treatment using a three-section, nine-section tunnel-type microwave unit, with a total travel time of 15 minutes. The microwave frequency of the tunnel-type microwave unit was 2450MHz, the first section was a preheating section, with a microwave power of 2.5kW / section, the second section was a thawing section, with a microwave power of 3.5kW / section, the third section was a heating section, with a microwave power of 5kW / section, and only the preheating section and the thawing section were subjected to synchronous dehumidification treatment by a dehumidifying fan. The central temperature of the blueberry leaves at the tunnel exit was 55°C, and thawed blueberry leaves were obtained.

[0095] Step (3) extraction, coarse filtration, concentration, and fine filtration:

[0096] The blueberry leaves after cell wall breaking are put into a continuous countercurrent extraction unit, and the blueberry leaves after cell wall breaking are extracted by using a continuous countercurrent extraction process and edible alcohol with an ethanol volume fraction of 70%. Among them, the feed rate is 18Kg / h, the liquid feed rate is 475L / h, the extraction temperature is 40℃, and the time is 9h. Then, a 60-mesh rotary filter is used for online filtration, and the filter residue is squeezed and collected for standby use. The filtrate is pumped into a single-effect three-stage scraper concentrator for concentration, the concentration temperature is 40-60℃, the vacuum degree is -0.04-0.095Mpa, and the ethanol concentration of the concentrate is monitored online until ≤1% (W / V) is the concentration end point. Subsequently, the concentrate is pumped into an open flow or dark flow plate frame, and impurities are removed by plate and frame filter pressing, using P450 filter cloth and a filtration pressure of 0.4-0.6MPa.

[0097] Step (4) separation, purification, concentration and powder making:

[0098] The extracted concentrated solution was pumped into a LYD-801 food industry adsorption resin (resin bed layer is 40cm diameter x 240cm high, each column resin amount is 196kg) for adsorption, and the flow line velocity of the leaf residue treatment liquid is 6.6cm / min. Then, 5 column volumes of pure water with a pH of 5.3 were used to wash the column at a flow line velocity of 4.4cm / min, and the washing column liquid was collected at the same time. Subsequently, 6 column volumes of alcohol with an ethanol volume fraction of 70% were used for desorption at a flow line velocity of 4.4cm / min. Then, a centrifugal scraper film evaporator was used for constant temperature and reduced pressure concentration, the concentration temperature was 55-65°C, the vacuum degree was -0.04-0.095MPa, and the concentration end point was when the ethanol volume fraction of the concentrated solution was ≤1% (V / V) by online monitoring, and the alcohol was recovered at the same time. Next, spray drying was performed, with an inlet air temperature of 140 to 180° C., an exhaust air temperature of 80 to 95° C., and the exhaust air was fully opened. The inlet air volume was adjusted so that the pressure in the spray tower was -50 to -100 Pa, and a blueberry leaf extract powder was obtained. The blueberry leaf extract powder weighed 15.69 kg and had a total polyphenol content of 39.89%.

[0099] Step (5) post-processing:

[0100] The blueberry leaf extract powder obtained in step (4) is put into a square cone IBC barrel tumbling mixer for batch mixing, with a tumbling frequency of 50 Hz and a mixing time of 3 hours; it is crushed by an ultrafine grinder, sieved by an ultrasonic vibrating screen, and then the metal foreign matter is removed by a four-layer drawer-type iron remover with a magnetic force of ≥10,000 Gauss for each magnetic rod, and finally a servo motor spiral feeding quantitative packaging machine is used with a quantitative accuracy of +0.5 grams. During this period, the transmission of materials in each step is carried out by a vacuum feeder pipeline closed operation to achieve dust-free operation, and finally 15.46 kg of blueberry leaf extract powder product is obtained.

[0101] Step (6) Clean production:

[0102] The filter residue obtained in step (3) is recycled as a natural fertilizer for organic blueberry cultivation or a raw material for pet food; the alcohol fraction produced by evaporation in the concentration process of steps (3) and (4) is distilled in a high-speed centrifugal distillation machine and then recycled into the next batch of production processes.

[0103] Example 6

[0104] Step (1) Pretreatment:

[0105] Fresh blueberry leaves are picked, washed by bubbling, drained, air-dried, and quick-frozen at a temperature of -40 to -35°C and a speed of 1.0 ton of blueberry leaves per hour. They are then stored in a freezer at a temperature of -20 to -18°C and a humidity of 85% to 95%.

[0106] Step (2) wet grinding and wall breaking:

[0107] 125 kg of frozen blueberry leaves (artificially grown Blue Beauty No. 1 blueberry leaves, with a polyphenol content of 12.01%) were added to 60°C hot water and mixed by high-speed shearing and stirring, and then pumped into a vertical precision wet grinder for cyclic grinding and cutting to complete cell wall breaking. The material-liquid ratio of blueberry leaves to hot water was 1:2 (W / V), the rotating disk speed was 6000-9000 rpm / min, the grinding time was 4-8 minutes, and the cell wall breaking was completed.

[0108] Step (3) extraction, coarse filtration, concentration, and fine filtration:

[0109] The blueberry leaves after cell wall breaking are put into a continuous countercurrent extraction unit, and the blueberry leaves after cell wall breaking are extracted by using a continuous countercurrent extraction process and edible alcohol with an ethanol volume fraction of 70%. Among them, the feed rate is 18Kg / h, the liquid feed rate is 475L / h, the extraction temperature is 40℃, and the time is 9h. Then, a 60-mesh rotary filter is used for online filtration, and the filter residue is squeezed and collected for standby use. The filtrate is pumped into a single-effect three-stage scraper concentrator for concentration, the concentration temperature is 40-60℃, the vacuum degree is -0.04-0.095Mpa, and the ethanol concentration of the concentrate is monitored online until ≤1% (W / V) is the concentration end point. Subsequently, the concentrate is pumped into an open flow or dark flow plate frame, and impurities are removed by plate and frame filter pressing, using P450 filter cloth and a filtration pressure of 0.4-0.6MPa.

[0110] Step (4) separation, purification, concentration and powder making:

[0111] The extracted concentrated solution was pumped into a LYD-801 food industry adsorption resin (resin bed layer is 40cm diameter x 240cm high, each column resin amount is 196kg) for adsorption, and the flow line velocity of the leaf residue treatment liquid is 6.6cm / min. Then, 5 column volumes of pure water with a pH of 5.3 were used to wash the column at a flow line velocity of 4.4cm / min, and the washing column liquid was collected at the same time. Subsequently, 6 column volumes of alcohol with an ethanol volume fraction of 70% were used for desorption at a flow line velocity of 4.4cm / min. Then, a centrifugal scraper film evaporator was used for constant temperature and reduced pressure concentration, the concentration temperature was 55-65°C, the vacuum degree was -0.04-0.095MPa, and the concentration end point was when the ethanol volume fraction of the concentrated solution was ≤1% (V / V) by online monitoring, and the alcohol was recovered at the same time. Next, spray drying was performed, with an inlet air temperature of 140 to 180° C., an exhaust air temperature of 80 to 95° C., and the exhaust air was fully opened. The inlet air volume was adjusted so that the pressure in the spray tower was -50 to -100 Pa, and a blueberry leaf extract powder was obtained. The blueberry leaf extract powder weighed 15.44 kg and had a total polyphenol content of 38.89%.

[0112] Step (5) post-processing:

[0113] The blueberry leaf extract powder obtained in step (4) is put into a square cone IBC barrel tumbling mixer for batch mixing, with a tumbling frequency of 50 Hz and a mixing time of 3 hours; it is crushed by an ultrafine grinder, sieved by an ultrasonic vibrating screen, and then the metal foreign matter is removed by a four-layer drawer-type iron remover with a magnetic force of ≥10,000 Gauss for each magnetic rod, and finally a servo motor spiral feeding quantitative packaging machine is used with a quantitative accuracy of +0.5 grams. During this period, the transmission of materials in each step is carried out by a vacuum feeder pipeline closed operation to achieve dust-free operation, and finally 15.22 kg of blueberry leaf extract powder product is obtained.

[0114] Step (6) Clean production:

[0115] The filter residue obtained in step (3) is recycled as a natural fertilizer for organic blueberry cultivation or a raw material for pet food; the alcohol fraction produced by evaporation in the concentration process of steps (3) and (4) is distilled in a high-speed centrifugal distillation machine and then recycled into the next batch of production processes.

Claims

1. A method for clean, efficient and large-scale preparation of blueberry leaf extract, characterized in that: The steps include: (1) Pretreatment: fresh blueberry leaves are picked and washed by bubbling, drained, air-dried, quick-frozen, and stored in a frozen state; (2) Cell wall disruption: a) Steam explosion: placing the frozen blueberry leaves obtained in step (1) into the material bin of a steam explosion reactor, pressurizing with steam, maintaining the pressure, and releasing the pressure to complete the wall breaking; b) Microwave freeze-thaw cell wall breaking: the frozen blueberry leaves obtained in step (1) are placed in a tunnel-type microwave oven and heated by microwaves for 6 to 15 minutes until the center temperature of the blueberry leaves at the tunnel outlet is 50±10° C., thus completing cell wall breaking; c) Wet grinding and cell wall breaking: the frozen blueberry leaves obtained in step (1) are added with hot water and mixed, and pumped into a vertical precision wet grinding machine for 4 to 8 minutes to complete cell wall breaking; One or more of the above are used to break the cell wall; (3) Extraction, coarse filtration, concentration, and precision filtration: The cell-wall-broken blueberry leaves obtained in step (2) are successively subjected to acid water or acidified edible alcohol extraction, filtration, concentration, and precision filtration to obtain an extract concentrate and a filter residue, respectively; (4) separation, purification, concentration and powder making: the extract concentrate obtained in step (3) is pumped into an adsorption resin chromatographic column at a constant flow rate for adsorption, and the column is first desorbed by washing the column with water at room temperature, and then desorbed by washing the column with aqueous edible alcohol; the edible alcohol washing column effluent is then concentrated at a constant temperature and reduced pressure; the concentrate is spray dried, and sterilization and powder making are performed simultaneously; (5) Post-processing: the blueberry leaf extract powder obtained in step (4) is batch mixed, crushed, and sieved, and then the metal foreign matter is removed by an iron remover, and finally the product is packaged by an automatic powder packaging machine; (6) Clean production: The filter residue obtained in step (3) is recycled as a natural fertilizer for organic blueberry cultivation or a raw material for pet food; the alcohol fraction produced by evaporation in the concentration process of steps (3) and (4) is distilled in a high-speed centrifugal distillation machine and then put into the next batch of production for recycling.

2. A method for clean, efficient and large-scale preparation of blueberry leaf extract according to claim 1, characterized in that: In the step (1), the blueberry leaves are washed and dried continuously by a bubbling washing + draining + air drying integrated machine; the quick freezing is performed by a tunnel quick freezer or a quick freezing warehouse, the quick freezing temperature is -40 to 35°C, and the quick freezing speed is 1.0 ton of blueberry leaves / hour; the blueberry leaves are stored in a freezer, the storage temperature is -20 to -18°C, and the storage humidity is 85% to 95%.

3. The method for clean, efficient and large-scale preparation of blueberry leaf extract according to claim 1, characterized in that: The steam explosion wall breaking in step (2) a) adopts a steam explosion machine, the explosion steam pressure is 1.0 MPa (180-190° C.), and the pressure holding time is 90 seconds.

4. The method for clean, efficient and large-scale preparation of blueberry leaf extract according to claim 1, characterized in that: The microwave freeze-thaw wall breaking in step (2) b) adopts a tunnel-type microwave machine, the microwave power is 2.5-5Kw / section, the microwave frequency is 2300-2600MHz, the conveying speed of blueberry leaves is 300-1000Kg / h, the total stroke is 6-15min, and the center temperature of the blueberry leaves at the tunnel outlet is 50±10°C.

5. The method for clean, efficient and large-scale preparation of blueberry leaf extract according to claim 1, characterized in that: The wet fine grinding and wall breaking in step (2) c) adopts a vertical precision wet grinding and cutting machine, the material-liquid ratio of blueberry leaves to hot water is 1:2 (W / V), the rotating disk speed is 6000-9000 rpm / min, and the grinding time is 4-8 min.

6. The method for clean, efficient and large-scale preparation of blueberry leaf extract according to claim 1, characterized in that: The extraction solvent in step (3) is water containing 0.5-3% glacial acetic acid or edible alcohol containing 0.5-3% glacial acetic acid and having an ethanol volume fraction of 50-80%, the extraction material-liquid ratio is 1:10-1:40 (W / V), the hot reflux extraction temperature is 40-60° C., and the extraction time is 3-9 hours; Use a rotary drum filter for coarse filtration with a filtration mesh of 50 to 70 meshes; A centrifugal scraper film evaporator or an external circulation single-effect or multiple-effect evaporator is used for constant temperature and reduced pressure concentration, the concentration temperature is 40 to 60° C., the vacuum degree is -0.04 to -0.095 MPa, and the concentration end point is when the ethanol concentration of the concentrated liquid is ≤1% (W / V) under online monitoring; Use open-flow or dark-flow plate and frame filter press for precision filtration, use P450 filter cloth, and the filtration pressure is 0.4-0.6MPa.

7. The method for clean, efficient and large-scale preparation of blueberry leaf extract according to claim 1, characterized in that: The adsorption resin used for separation and purification in step (4) is a single functional group having a carboxyl group, an ester group or a hydroxyl group, or a gel resin or a macroporous resin having a bifunctional group having both a hydroxyl group and an ester group, both a hydroxyl group and an amide group, or both an ester group and an amide group; the diameter-to-height ratio of the chromatographic column is 1:6-1:7, the specific loading amount in terms of polyphenols is 9.0-25.0 mg / g, and the flow linear velocity of the loading liquid is 2-9 cm / min; the column is washed with 2-6 column volumes of water at room temperature for desorption, and then the column is washed with 4-12 column volumes of edible alcohol at room temperature with an ethanol volume fraction of 20-80%; the flow linear velocity of the water and alcohol desorption washing liquids is 2-9 cm / min; The concentration in step (4) is carried out by a centrifugal scraper thin film evaporator at a constant temperature and reduced pressure, the concentration temperature is 55 to 65° C., the vacuum degree is -0.04 to -0.095 MPa, and the concentration end point is when the volume fraction of ethanol in the concentrated solution reaches ≤1% (V / V); In the step (4), the powder is prepared by spray drying, the spray drying inlet air temperature is 140-180°C, the exhaust air temperature is 80-95°C, the exhaust air is fully opened, and the inlet air volume is adjusted so that the pressure in the spray tower is -50 to -100 Pa.

8. The method for clean, efficient and large-scale preparation of blueberry leaf extract according to claim 7, characterized in that: When desorption is carried out by washing the column with water at room temperature in step (4), the effluent from the washing column is discharged into a sewage treatment station and used as nutrients for microorganisms.

9. The method for clean, efficient and large-scale preparation of blueberry leaf extract according to claim 7, characterized in that: In the step (4), the volume of the water-washed column is 5 times the column volume; the desorption liquid is edible alcohol with an ethanol volume fraction of 70%, and the volume of the desorption liquid is 6 times the column volume; and the desorption is performed at a flow linear velocity of 4.4 cm / min.

10. The method for clean, efficient and large-scale preparation of blueberry leaf extract according to claim 1, characterized in that: The batch mixing in step (5) is carried out using a square cone IBC barrel tumbling mixer with a tumbling frequency of 50 Hz and a mixing time of 3 hours; Use ultra-fine pulverizer for crushing, and close the air valve to discharge the material; Ultrasonic vibrating screen is used for screening; The iron remover adopts a four-layer drawer-type iron remover with a magnetic force of each magnetic rod ≥ 10,000 Gauss; The product packaging adopts servo motor spiral feeding quantitative packaging machine with a quantitative accuracy of +0.5 grams; In the above steps, the material transmission is carried out in a closed pipeline by a vacuum feeder.