Hovenia Dulcis Dihydromyricetin: Value, Production Process and Application Prospects

Core Active Ingredient: Value and Properties of Dihydromyricetin

Hovenia dulcis, also known as Japanese raisin tree or honey tree, is a traditional medicinal and edible material in China. Its core active ingredient, Dihydromyricetin (DMY), is a flavonoid compound. It has been studied in published research for antioxidant, alcohol-metabolism, hepatic, anti-inflammatory, lipid-related, and metabolic activity, and is widely used as a raw material in natural health foods, dietary supplements, and high-end cosmetics.

The original content of DMY in dried natural Hovenia dulcis seeds is only 0.05%–0.6%, and can reach nearly 1% in high-quality producing areas. Direct consumption is ineffective; professional extraction and purification are required to enrich DMY to 8%–98% to meet industrial application demands, which is the key to high-value utilization of Hovenia dulcis resources.

Compared with other flavonoids, DMY has stable physicochemical properties and good biocompatibility. In published research it has been studied for free-radical scavenging, cellular oxidative-stress, acetaldehyde (alcohol-metabolite) decomposition, and hepatic-cell endpoints, supporting its broad application potential as a functional ingredient.

Industrial Extraction Process: Efficient Enrichment, Green & Controllable

Ethanol thermal reflux extraction is the preferred industrial process due to recyclable solvent, controllable cost, high efficiency, compliance with food and drug safety standards, and environmental friendliness. The detailed workflow and core parameters are as follows:

Raw Material Pretreatment

Select mature, impurity-free, mold-free Hovenia dulcis seeds, dry to moisture < 10% to prevent degradation. Crush to 20–40 mesh for sufficient solid-liquid contact while avoiding filter clogging or incomplete extraction.

Ethanol Thermal Reflux Extraction

Use 50%–70% food-grade ethanol as solvent (high selectivity, low impurity leaching). Solid-liquid ratio: 1:8–1:12. Extract twice at 70–80 °C: first for 2 h, second for 1.5 h. Combine extracts.

Filtration and Vacuum Concentration

Remove residue via plate-and-frame filtration or high-speed centrifugation. Concentrate under vacuum at 55–65 °C, vacuum -0.07 to -0.09 MPa, adjust concentrate specific gravity to 1.05–1.10. Low temperature prevents degradation; recycled ethanol reduces cost.

Gradient Purification Process: Graded Customization for Diverse Scenarios

Three purity grades balance efficiency and quality to meet client needs:

General Food Grade (8%–20%)

For functional foods and beverages. Simplest, lowest cost: spray-dry or vacuum-dry crude concentrate directly without further purification. Suitable for large-scale production.

Mid-to-High-End Supplement Grade (30%–50%)

For supplements positioned in the alcohol-metabolism, liver-health, and antioxidant formulation categories. Core: macroporous resin purification (D101, AB-8).

• Load at 1–2 BV/h

• Wash with 2–3 BV pure water to remove sugars, pigments, polysaccharides, proteins

• Elute with 30%–50% ethanol

• Concentrate and dry to obtain high-activity extract

Pharmaceutical / High-End Cosmetic Grade (90%–98%)

For pharmaceuticals, anti-aging cosmetics, and research reagents. Add crystallization-recrystallization after resin purification:

• Dissolve in 80%–90% ethanol

• Decolorize with 1%–2% food-grade activated carbon at 60 °C for 30 min

• Cool slowly to 10–20 °C, hold 8–12 h for crude crystals

• Recrystallize 1–2 times in ethanol-water system

• Vacuum dry: purity ≥98%

Precise Quality Detection: Authoritative & Compliant

Two standard methods ensure accuracy:

High-Performance Liquid Chromatography (HPLC)

Gold standard for third-party testing, registration, and export.

• C18 column

• Mobile phase: methanol:water = 45:55

• Detection wavelength: 292 nm

• External standard method

• High precision, repeatable, officially recognized.

Ultraviolet Spectrophotometry (UV)

For in-process control and rapid screening. Simple, fast, low-cost. Measure absorbance at 292 nm, quantify via standard curve for real-time monitoring.

Key Process Control Points

1. Ethanol concentration strictly 50%–70% to ensure extraction rate.

2. Thorough water washing in resin purification to avoid pigment/polysaccharide residue.

3. Slow cooling in crystallization; no rapid chilling to prevent impurity inclusion.

4. Processing temperature ≤80 °C. Store finished products light-proof, sealed, dry.

Industrial Prospects & Technical Outlook

Demand for high-purity DMY is rising rapidly with the natural health industry. Hovenia dulcis as a premium natural source has growing industrial value.

Future trends:

• Ultrasound- and microwave-assisted extraction for higher efficiency

• Solvent-free green purification

• Full-component comprehensive utilization for zero waste and high-value development

• Promoting sustainable growth of the plant extract industry