By Thin-Film Evaporation and Short-Path Molecular Distillation
How ANVORE's gentle, oxygen-free physical separation platform refines crude fish oil into clear, low-odor, high-purity EPA/DHA omega-3 concentrates — in seconds of thermal exposure instead of the hours demanded by conventional deodorization.
| 0.1-1 Pa | Seconds | 120-250 °C | 0 solvent |
|---|---|---|---|
| Molecular still operating pressure | Thermal residence time | Evaporation window, tuned per oil form | Purely physical separation |
1. Application Overview
Fish oil is the primary commercial source of the long-chain omega-3 fatty acids EPA and DHA, widely used in dietary supplements, functional foods, infant nutrition and clinical nutrition. Crude fish oil, however, arrives as a complex and fragile matrix: triglycerides mixed with free fatty acids, cholesterol, waxes, pigments, protein residues, volatile odor compounds and environmental contaminants — while EPA and DHA themselves are highly unsaturated and easily oxidized, isomerized or polymerized by heat and oxygen.
Conventional refining — long-path high-temperature deodorization and steam stripping — exposes the oil to 200 °C and above for extended periods, consuming natural antioxidants, darkening the oil and leaving fishy off-odors. ANVORE replaces this with a two-stage wiped-film physical separation platform: thin-film evaporation first strips the light burden, then short-path molecular distillation concentrates EPA/DHA under deep vacuum within seconds of exposure.
2. ANVORE Solution
ANVORE sequences two complementary wiped-film technologies so each operates in its optimum window, with the whole train running closed and oxygen-free:
1. Thin-film evaporation stage —the pre-treated oil is spread into a thin falling film; residual free fatty acids, cholesterol, moisture and volatile odor compounds are stripped overhead at moderate vacuum, de-burdening the refining stage.
2. Short-path molecular distillation stage —at 0.1-1 Pa the omega-3 esters vaporize at survivable temperatures and cross the mean-free-path distance to the built-in internal condenser; heavy pigments, polymers and contaminants never evaporate. Multi-stage operation cascades the assay upward.
3. Hermetic, oxygen-free operation —fully closed equipment with nitrogen blanket option — the oil never contacts air, protecting color, flavor and oxidative stability.
4. Seconds of thermal exposure —high-speed wiper blades continuously renew the liquid film; the oil spends seconds on the hot surface instead of the long hold-up of batch deodorization, with tight, hotspot-free temperature control.
3. Complete Purification Process Flow
The purification campaign runs continuously; each stage below maps to the flow diagram in Figure 3:
Step 1 · Degumming & Deacidification —Crude fish oil is treated with phosphoric acid to hydrate and remove phospholipids and gums, then alkali-refined to neutralize free fatty acids.
Step 2 · Bleaching & Filtration —Adsorbent bleaching removes pigments and oxidation products; filter pressing clarifies the oil and protects downstream equipment.
Step 3 · Ethyl Esterification —For high-concentration omega-3 grades, the triglycerides are converted to fatty-acid ethyl esters, sharply lowering the boiling points for gentler distillation. Triglyceride-form products skip this step and run at higher temperature.
Step 4 · Degassing & Drying —Under moderate vacuum the oil is degassed to strip moisture, dissolved oxygen and volatile odor compounds — the first act of product protection.
Step 5 · Thin-Film Evaporation —The wiped-film evaporator removes remaining free fatty acids, cholesterol and light-end impurities overhead; the omega-3-rich stream continues forward.
Step 6 · Molecular Distillation —In the short-path still at 0.1-1 Pa, EPA/DHA esters vaporize from the wiped film within seconds and condense instantly on the internal condenser. Stage by stage, the omega-3 content is stepped up to the target concentration.
Step 7 · Collection & Residue Discharge —Refined omega-3 distillate is discharged to sealed, nitrogen-blanketed receivers; heavy residue — polymers, pigments and contaminants — is drained continuously.
4. Key Parameters & Process Advantages
| Parameter | Typical range / description |
|---|---|
| Feed | Crude or semi-refined fish oil; ethyl-ester or triglyceride form |
| Molecular still pressure | 0.1-1 Pa, high-vacuum train |
| Evaporation temperature | 120-250 °C — lower for ethyl esters, higher for triglycerides |
| Wiper speed | 100-400 rpm, uniform thin film |
| Residence time | Seconds on the heated surface |
| Product handling | Sealed receivers, nitrogen blanket, antioxidant-protected |
Compared with conventional high-temperature deodorization, the ANVORE route consistently delivers:
- Higher EPA/DHA retention — gentle, seconds-long exposure prevents oxidation, isomerization and polymerization losses.Cleaner sensory profile — volatile odor compounds and free fatty acids are physically stripped, yielding light-colored, low-odor oil.Flexible concentration — single or multi-stage cascades step omega-3 content up from feed level to the target specification.Solvent-free and scalable — purely physical continuous operation, from bench verification to full production lines.
5. Conclusion & One-Stop Support
Fish oil purification is a race against heat, oxygen and time. The ANVORE two-stage platform wins that race by design: thin-film evaporation removes the light burden, and short-path molecular distillation refines the omega-3 fraction at 0.1-1 Pa within seconds — preserving the potency, color and flavor that conventional routes surrender.
ANVORE provides free bench testing with your fish oil, customized process design, complete equipment supply and on-site commissioning — scaling smoothly from laboratory glass units to stainless-steel production systems.
Send us your fish oil sample for free verification. Contact ANVORE for tailored process design and equipment selection. ANVORE — Gentle Separation, Purer Omega-3.
