The industrial production of erythritol mainly adopts microbial fermentation method, rather than directly extracting from natural plants. This is because erythritol has a low content in nature, and direct extraction is costly and inefficient. The following are the core processes and technical points for industrial production of erythritol:

Mainstream production method: Microbial fermentation method
Selection of bacterial strains

Core strains: High producing erythritol yeast (such as Moniliella pollinis, Yarrowia lipolytica) or mold (such as Trichosporonoides megachiliensis).
Genetic engineering optimization: Modern technology enhances the sugar alcohol conversion rate and high osmotic pressure resistance of bacterial strains through genetic modification.
Raw material processing

Carbon source: Use glucose or sucrose solution (with a concentration of up to 30-35%, creating a high osmotic environment to promote erythritol synthesis).
Pre treatment: Cheap raw materials such as corn starch need to be converted into glucose through enzymatic hydrolysis (α - amylase+amylase).
Fermentation process

Oxygen controlled fermentation: Conduct deep aeration fermentation in large fermentation tanks, strictly control pH (5.0-6.0), temperature (28-34 ℃), and dissolved oxygen level.
High osmotic pressure induction: Under high glucose concentration, microorganisms convert some glucose into erythritol to balance cell osmotic pressure.
Key steps for separation and purification

Technical details of steps
Sterilization filtration, microfiltration or centrifugation to remove bacterial cells and large molecular impurities
Decolorization desalination activated carbon adsorbs pigments, ion exchange resin removes inorganic salts
Concentrated crystallization vacuum evaporation concentration to supersaturation → cooling crystallization (controlling seed addition and cooling rate)
Centrifugal drying, centrifugal separation of crystals → fluidized bed drying to obtain white crystals with purity greater than 99.5%
Natural presence and minimal scale extraction (non industrial)
Although industrial production relies on fermentation, erythritol naturally exists in:

Fruits: grapes, pears, watermelon (content about 0.005-0.1%)
Fermented foods: soy sauce, sake
Extraction experimental method (for scientific research purposes only):
mermaid
Copy Code
graph LR
A [Sample Grinding] -->B [Hot Water Extraction]
B -->C [Ethanol precipitation polysaccharides]
C -->D [ion exchange chromatography purification]
D -->E [HPLC separation of erythritol]
Disadvantages: Extremely low yield (<0.02%), high cost, and inability to commercialize.
Comparative advantages with other sugar alcohol production
Characteristic erythritol xylitol/sorbitol
Fermentation substrate glucose/sucrose hemicellulose hydrolysate (xylose)
Crystallization difficulty: Easy to crystallize (solubility of 37g/100g at 25 ℃). Sorbitol needs to crystallize slowly to prevent clumping
Metabolic pathway: The human body does not metabolize (<10% absorbed) xylitol partially metabolizes (insulin participates)
Technological progress
Waste utilization: Attempt to replace refined glucose with lignocellulose hydrolysate to reduce raw material costs by more than 30%.
Continuous fermentation: The new membrane bioreactor achieves continuous production, shortening the fermentation cycle to 48 hours.
Green crystallization: Ultrasonic assisted crystallization technology improves crystal purity (>99.9%) and reduces energy consumption.
Conclusion
The "extraction" of erythritol actually refers to the industrial fermentation separation process, and natural extraction only has theoretical significance. Modern technology uses genetically engineered strains, high concentration fermentation, and multiple refining techniques to achieve low-cost production of millions of tons per year, meeting the demand for zero sugar food. If specific process parameters or strain patent information are required, further literature support can be provided.