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CN-121974966-A - Method for extracting rubusoside from golden sweet tea and preparing high-concentration syrup

CN121974966ACN 121974966 ACN121974966 ACN 121974966ACN-121974966-A

Abstract

The invention relates to a method for extracting rubusoside from golden-xiu sweet tea and preparing high-concentration syrup, which belongs to the technical field of natural product extraction and food processing, and comprises the steps of carrying out explosion-proof crushing on raw materials, and obtaining refined liquid through countercurrent extraction and membrane filtration; the method comprises the steps of enriching rubusoside by adopting a chromatography process of serial adsorption-parallel analysis, debitterizing by using special resin, preparing high-purity syrup by using a double-effect flash evaporation concentration system under low-temperature vacuum, and integrating ethanol condensation, recycling and reusing. The invention realizes continuous and explosion-proof production, and has the characteristics of high extraction efficiency, high product purity, low energy consumption, recyclable solvent and safe and controllable production process.

Inventors

  • HUANG YUYUAN
  • WEI YULIN

Assignees

  • 黑马当先(金秀)绿色农业科技有限公司

Dates

Publication Date
20260505
Application Date
20260129

Claims (10)

  1. 1. A method for extracting rubusoside from sweet tea and preparing high-concentration syrup, which is characterized by comprising the following steps: S1, raw material pretreatment, namely selecting Jin Xiu sweet tea mature leaves, removing impurities, crushing to 80-100 meshes by using a 500kg/h explosion-proof crusher, controlling the temperature of a crushing cavity to be less than or equal to 35 ℃, conveying crushed materials to a 1m3 explosion-proof storage bin by using a 500kg/h vacuum feeder, and controlling the vacuum degree to be-0.06 to-0.08 MPa; S2, collaborative extraction, namely feeding bin materials into a 5m3 explosion-proof mixing pump at a rate of 50-60kg/h, introducing 40-45 ℃ purified water according to a solid-to-liquid ratio of 1:12, mixing slurry, performing series operation on the slurry through 2 sets of PFRphi 600 x 3500 plug flow extractors, controlling the first temperature to be 55-60 ℃ and stay for 30min, controlling the second temperature to be 60-65 ℃ and stay for 25min, pre-extracting, entering a phi 800 x 15000 countercurrent extraction unit, controlling the extraction temperature to be 65-70 ℃ and the extraction time to be 60min, and performing reflux extraction on slag materials after squeezing to obtain an extraction solution; S3, multistage filtration, namely centrifuging the extracting solution by a 5M3/H spiral centrifuge to remove impurities, controlling the rotating speed to be 3000-3500r/min and the feeding speed to be 4-5M3/H, separating the centrifugate by a DTSX-80 butterfly separator, and controlling the separation factor to be 5000-5500 to obtain centrifugate with the light transmittance of more than or equal to 90 percent, refining the centrifugate by a 3M3/H membrane filter, adopting a 100M2 ceramic ultrafiltration membrane with the molecular weight cutoff of 5000Da, and controlling the operating pressure to be 0.2-0.3MPa, the temperature to be 40-45 ℃ and the flow speed to be 1.5-2.0M3/H to obtain refined filtrate; S4, chromatographic enrichment, namely adsorbing the refined filtrate by using 6 sets of 1m3 chromatographic column systems, arranging AB-8 macroporous adsorption resin in the chromatographic column, controlling the flow rate of the upper column to be 1.5-2.0BV/h and the temperature to be 30-35 ℃, eluting impurities by using purified water after adsorption saturation, then resolving by using 60-65% ethanol solution, controlling the resolving flow rate to be 1.0-1.2BV/h and the temperature to be 40-45 ℃, and collecting resolved liquid; S5, debitterizing and optimizing, namely debitterizing the analysis solution through 3 sets of 1m3 debitterizing column systems, wherein D101 resin is filled in the debitterizing columns, the debitterizing flow rate is controlled to be 1.2-1.5BV/h, the temperature is controlled to be 35-40 ℃, and the removal rate of bitter components is ensured to be more than or equal to 85 percent, and the retention rate of rubusoside is ensured to be more than or equal to 95 percent; S6, double-effect concentration, namely primarily concentrating the debitterizing solution through a 3M3/h double-effect flash evaporation concentration evaporator, controlling the first-effect evaporation temperature to be 75-80 ℃ and the vacuum degree to be 0.06MPa, controlling the second-effect evaporation temperature to be 60-65 ℃ and the vacuum degree to be 0.08MPa, concentrating to the concentration of rubusoside to be 25-30mg/mL, deeply concentrating through a 1.5M3/h double-effect flash evaporation concentration evaporator, controlling the first-effect temperature to be 70-75 ℃ and the vacuum degree to be 0.07MPa, controlling the second-effect temperature to be 55-60 ℃ and the vacuum degree to be 0.09MPa, concentrating to the concentration of syrup to be 65-70Brix, and obtaining the high-concentration syrup with the rubusoside purity of more than or equal to 98%; and S7, recovering the solvent, namely condensing and recovering ethanol vapor generated in the concentration process through a 25M3 first-stage plate type condenser and a 5M3 second-stage plate type condenser, wherein the concentration of recovered ethanol is more than or equal to 85 percent, the recovery rate is more than or equal to 90 percent, and the ethanol content of tail gas after the tail gas is treated by a tower washing is less than or equal to 50mg/M < 3 >.
  2. 2. The method according to claim 1, wherein the feeding rate of the explosion-proof pulverizer in the step S1 is controlled to be 200-250kg/h, and the explosion-proof bin is provided with a 1.1KW metering screw and arch breaking device, and the micro negative pressure is kept in the bin to be-0.02 MPa.
  3. 3. The method of claim 1, wherein in the step S2, the single-machine frequency conversion of the plug flow extractor is 7.5KW, the temperature fluctuation is less than or equal to 2 ℃ in the extraction process, the counter flow extractor comprises a spiral slag extractor and a slag extruder, the pressing pressure is 0.8-1.0MPa, and the extracting solution is preliminarily filtered by a 80-mesh filter screen.
  4. 4. The method according to claim 1, wherein in step S3, when the membrane flux of the membrane filter is reduced to 80% of the initial value, an online backwash is performed with 0.1% naoh solution for 15min.
  5. 5. The method according to claim 1, wherein in the step S4, the 6 sets of chromatographic columns are divided into two groups, 3 chromatographic columns are connected in series, a series adsorption and parallel analysis mode is adopted, the adsorption end point is based on that the concentration of the rubusoside in effluent is more than or equal to 0.05mg/mL, and 2BV purified water is used for eluting impurities at a flow rate of 2.0BV/h before analysis.
  6. 6. The method according to claim 1, wherein the debittering effect in step S5 is verified by sensory evaluation and high performance liquid chromatography detection, and the bitterness score in the sensory evaluation is less than or equal to 1 point.
  7. 7. The method of claim 1, wherein the double-effect concentration evaporator in the step S6 is provided with a defoaming device, the concentration of the rubusoside after primary concentration is 25-30mg/mL, the water content of the syrup after deep concentration is less than or equal to 15%, and the secondary steam in the concentration process is used for preheating the feed liquid.
  8. 8. The method of claim 1, wherein the whole process adopts an explosion-proof electrical control system, uses a Siemens CPU as a core controller, is provided with an AI/AO module, an explosion-proof touch screen operation box and an emergency stop operation column, and automatically alarms and triggers equipment interlocking protection when technological parameters are out of limits.
  9. 9. A device system for implementing the method of any one of claims 1-8, comprising: the explosion-proof pretreatment unit comprises 500kg/h explosion-proof pulverizer, 500kg/h vacuum feeder and 1m3 explosion-proof bin; The explosion-proof extraction unit comprises a 5m3 explosion-proof mixing pump, 2 sets of PFR phi 600 multiplied by 3500 plug flow extractors, a phi 800 multiplied by 15000 countercurrent extraction unit and a 5m3 variable-frequency relay screw pump; The explosion-proof filter unit comprises a 5M3/H spiral centrifuge, DTSX-80 butterfly separators, a 3M3/H membrane filter, a centrifugate buffer tank, a filtrate storage tank and a matched explosion-proof pump; the explosion-proof chromatographic unit comprises 6 sets of 1m3 chromatographic column systems, a pneumatic diaphragm pump, an analytical liquid tank and a PP filter; the explosion-proof debittering unit is composed of 3 sets of 1m3 debittering column systems, a decoloring column material pump and a debittering liquid tank; the explosion-proof concentration unit comprises a 3M3/h double-effect flash evaporation concentration evaporator, a 1.5M3/h double-effect flash evaporation concentration evaporator, a concentrated solution storage tank and a concentrated solution tank; The explosion-proof recovery unit comprises a 25M3 primary plate type condenser, a 5M3 secondary plate type condenser, a vapor-liquid separator, a condensation recovery tank and an alcohol tank; the explosion-proof control system comprises an explosion-proof power distribution cabinet, a field valve island box, a touch screen operation box, a remote module, a PLC module and a sensor.
  10. 10. The equipment system according to claim 9, wherein the materials of the extraction unit, the filtering unit and the concentration unit are 304 stainless steel, the materials of the chromatography unit and the debitterizing unit are 316 stainless steel, and all motors, pumps and power distribution cabinets accord with GB3836.1-2010 explosion-proof standards, and the system grounding resistance is less than or equal to 4Ω.

Description

Method for extracting rubusoside from golden sweet tea and preparing high-concentration syrup Technical Field The invention relates to the technical field of natural product extraction and food processing, in particular to a method for extracting rubusoside from golden sweet tea and preparing high-concentration syrup. Background Jin Xiutian tea (Rubus suavissimus S. Lee) is a special medicinal and edible plant in Guangxi, the leaves of which are rich in rubusoside (Rubusoside), the sweetness of which is about 200-300 times that of sucrose, and the sweet taste is pure and the after-bitter taste is weak, so that the natural high-power sweetener with great development value is provided. Along with popularization of healthy diet concept and pursuit of clean label products in the market, the demand of natural sweetener is growing, jin Xiutian tea is used as a source of high-quality sweet substances, and high-value development and utilization of the natural sweetener are widely focused. At present, the method for extracting rubusoside from Jin Xiu sweet tea mainly comprises the traditional water extraction method, the alcohol extraction method and a process combining preliminary purification on the basis. Although the traditional water extraction method is simple to operate, the extraction efficiency is low, the energy consumption is high, the impurities in the extracting solution are more, and the subsequent purification difficulty is high. Although the extraction efficiency of the alcohol extraction method is improved, the alcohol extraction method has the advantages of high solvent consumption, high cost and solvent residue risk, and is not beneficial to food safety and environmental protection. In terms of purification, the conventional method mostly adopts a single resin adsorption, precipitation or conventional concentration process, and has the problems of low purification efficiency, low product purity (usually lower than 95%), incomplete removal of bitter and astringent taste and the like, so that the requirements of high-end food ingredients on flavor and purity are difficult to meet. In the existing large-scale production process, the technical bottlenecks are common, namely, the production process is relatively independent in units, the system integration and continuous design are lacked, the production efficiency is low, the labor intensity is high, the extraction and concentration processes are mainly operated at normal pressure and high temperature, heat-sensitive components such as rubusoside are easily decomposed, the activity and yield of products are influenced, the solvent recovery system is imperfect, the consumption and the emission of organic solvents such as ethanol are high, the production cost and the environmental protection pressure are outstanding, and the special anti-explosion equipment system aiming at the characteristics of raw materials and the requirements of products is lacked, so that the production safety and the automation degree are required to be improved. Therefore, the method and the matched equipment for industrially preparing the rubusoside high-concentration syrup, which can realize efficient extraction, deep purification, low-temperature concentration, solvent circulation, continuous production and safety and controllability, are developed, and have important significance for improving the utilization rate of Jin Xiu rubus suavissimus resources, reducing the production cost, guaranteeing the product quality and promoting the industrial upgrading of natural sweeteners. Disclosure of Invention The invention provides a method for extracting rubusoside from sweet tea and preparing high-concentration syrup, which aims to solve the problems in the prior art. In order to solve the technical problems, the invention is realized by the following technical scheme that in the first aspect, the method for extracting rubusoside from the golden sweet tea and preparing high-concentration syrup comprises the following steps: S1, raw material pretreatment, namely selecting Jin Xiu sweet tea mature leaves, removing impurities, crushing to 80-100 meshes by using a 500kg/h explosion-proof crusher, controlling the temperature of a crushing cavity to be less than or equal to 35 ℃, conveying crushed materials to a 1m3 explosion-proof storage bin by using a 500kg/h vacuum feeder, and controlling the vacuum degree to be-0.06 to-0.08 MPa; S2, collaborative extraction, namely feeding bin materials into a 5m3 explosion-proof mixing pump at a rate of 50-60kg/h, introducing 40-45 ℃ purified water according to a solid-to-liquid ratio of 1:12, mixing slurry, performing series operation on the slurry through 2 sets of PFRphi 600 x 3500 plug flow extractors, controlling the first temperature to be 55-60 ℃ and stay for 30min, controlling the second temperature to be 60-65 ℃ and stay for 25min, pre-extracting, entering a phi 800 x 15000 countercurrent extraction unit, controlling the extraction temperat