100L stevia extraction machine

Process flow of ultrasonic assisted extraction of stevia glycosides
1、 Basic preprocessing stage
Raw material cleaning and drying: Rinse the stevia leaves with clean water to remove impurities. Some processes involve soaking them in anhydrous ethanol for 30-100 minutes and then drying them at 60-70 ℃ to a moisture content of 5-10%.
Crushing and sieving: Grind the dried stevia leaves to 40-80 mesh to increase cell fragmentation rate and improve extraction efficiency.
2、 Ultrasonic extraction stage
Extract parameter control:
Material to liquid ratio: 1:8-1:15 (mass ratio of steviol powder to extract).
Temperature: 60-80 ℃ (to avoid high temperature damaging the activity of stevia glycosides).
Power: 200-3000W (depending on equipment specifications).
Time: 60-80 minutes, extract twice and combine the filtrate.
Operation process: Mix the preprocessed stevia powder with water (or ethanol) in proportion, place it in an ultrasonic extraction tank, perform ultrasonic extraction under set parameters, and filter to obtain the extraction solution.
3、 Purification and post-processing stage
Alcohol precipitation for impurity removal: Concentrate the extract to 300mL, add 95% ethanol dropwise at a rate of 15mL/min to the concentrate, let it stand for 2.5 hours, centrifuge, wash the precipitate and combine the filtrate, and concentrate to 250mL.
Resin purification:
Macroporous resin adsorption: AB-8 resin is selected, first soaked in 95% ethanol for 24 hours, then rinsed with deionized water until colorless, and the extract is adsorbed on the column, washed with 70% ethanol until the effluent has no sweet taste.
Ion exchange resin desalination: The eluent is passed through a cation exchange resin column to remove inorganic salt impurities.
Discoloration and deodorization: Add activated carbon to heat up and reflux for decolorization, filter while hot; Some processes will further remove odors through deodorizing resin.
Concentration and drying: reduce the pressure of the purified extract to 30% -40% of the solid content, and then dry it by spray (inlet air temperature 180-200 ℃, outlet air temperature 80-90 ℃) to obtain white powder stevioside products.
4、 Process optimization direction
Enzyme assisted extraction: adding cellulase (0.15% dosage) before ultrasonic extraction to destroy the cell wall can increase the extraction rate by 2.90%, while reducing the extraction temperature.
Membrane separation technology: ceramic membranes (pore size 30-50nm) and ultrafiltration membranes (molecular weight cut-off 1000-5000) are used to filter the extraction solution, achieving efficient impurity removal and improving product purity.
5、 Technological advantages
High extraction efficiency: The ultrasonic assisted extraction of stevia glycosides can achieve an extraction rate of 12% -15%, which is 14.6% -2.9% higher than the traditional water extraction method.
Short time: The single extraction time only takes 60-80 minutes, which is more than 50% shorter than traditional methods.
Environmental protection and energy conservation: The BOD of wastewater is below 100, supporting recycled water and meeting the requirements of green production

Working principle of Ultrasonic assisted extraction of stevia glycosides

The core principle of ultrasound assisted extraction is to utilize the cavitation, mechanical, and thermal effects of ultrasound to accelerate the release of steviol glycosides from cells
Cavitation effect: Ultrasonic waves generate tiny bubbles in liquid, which release energy when the bubbles burst, damaging the cell wall of stevia and causing rapid dissolution of steviol glycosides.
Mechanical effect: The shear force generated by ultrasonic vibration further breaks down the cell structure and expands the extraction contact area.
Thermal effect: Ultrasonic local heating promotes the diffusion of steviol glycosides, but temperature control is necessary to avoid degradation of active ingredients.
Equipment structure (inferred based on process flow)
Ultrasonic assisted extraction equipment typically includes the following core modules:
Ultrasonic Generation System: Composed of an ultrasonic generator and transducer, it converts electrical energy into high-frequency mechanical vibration (common power of 200-3000W, frequency of 20-40kHz).
Extraction tank: made of corrosion-resistant stainless steel material, with built-in ultrasonic transducer, supporting material to liquid ratio adjustment (commonly 1:8-1:15) and temperature control (60-80 ℃).
Crushing and pretreatment module: Equipped with a grinder, the dried leaves of Stevia rebaudiana are crushed to 60-80 mesh, increasing the cell fragmentation rate.
Filtration and concentration system: including plate and frame filters, vacuum concentration tanks, used for separating residues and concentrating extraction liquids.

Control system: integrates temperature, time, and power regulation functions to achieve automated operation.

Equipment type and composition
Stevia extract machine belongs to plant extraction equipment, usually a multifunctional extraction and concentration unit, mainly including the following core components:
Extraction tank: supports static or dynamic extraction, with various volume specifications (50L, 100L, 200L, 300L, etc.), and users can choose according to their production needs

1.Ultrasonic Generation System
Composed of an ultrasonic generator (which converts electrical energy into high-frequency electrical signals) and a transducer (which converts electrical signals into mechanical vibrations), with a common power of 2000-3000W and a frequency of 20-40kHz, it breaks down the cell wall of Stevia rebaudiana through cavitation effect.
2.extraction tank
Corrosion resistant 304/316L stainless steel material, built-in ultrasonic transducer, supports material to liquid ratio adjustment (1:8-1:15) and temperature control (60-80 ℃), and some equipment is equipped with a stirring system to improve extraction uniformity.
3.Crushing and pre-processing module
The supporting crusher crushes the dried leaves of sweet chrysanthemum to 40-80 mesh, increasing the cell fragmentation rate and improving the extraction efficiency.
4.Filtration and concentration system
It includes plate and frame filter (to separate residue), vacuum concentration tank (to concentrate the extract to 30% -40% solid content), and some equipment integrates spray drying function.
5.intelligent control system
Integrated temperature, time, and power regulation functions, supporting automated operations and reducing manual intervention.

6.Auxiliary systems: condenser, condensate collection tank, oil-water separator, filter, feed liquid transfer pump, vacuum pump, electronic control system, etc

Technical parameters and characteristics
Material and Safety: The equipment is made of 304 or 316L stainless steel, with finely polished inner and outer surfaces that are corrosion-resistant, easy to clean, and meet food/pharmaceutical grade production standards
Heating method: Supports steam heating or electric heating, can be used without the need for a boiler heat source, and is evenly heated
Function integration: integrates extraction, concentration, and solvent recovery, suitable for the extraction process of various materials such as stevia and traditional Chinese medicine
Convenient operation: Equipped with a stainless steel control cabinet to achieve automatic temperature control and display. The internal pipelines of the system have been connected, and users only need to connect water and electricity to use it

Application scenarios and advantages
Industrial production: suitable for large-scale extraction of stevia glycosides, with an extraction rate of 12% -15% (14.6% -2.9% higher than traditional water extraction), and an extraction time shortened to 60-80 minutes.
Laboratory research: used for analysis of steviol glycoside content and optimization of process parameters (such as liquid to material ratio, ultrasound power, temperature).
Environmental advantages: reducing the use of organic solvents, wastewater BOD below 100, supporting recycled water, in line with green living standards

Do you need to know specific equipment recommendations or pricing information? Or would you like to further explore the optimization direction of stevia glycoside extraction process? Welcome to visit us or email via info@bioland-china.com