Lutein Extraction Process

I. Basics and Raw Materials

Raw Material: Marigold (highest lutein ester content, approximately 1.5–2.5 g/100g dried flowers)

Main Component: Lutein esters, which can be saponified into free lutein after extraction.

Applications: Food/feed additives, health products, pharmaceuticals, cosmetics

II. Raw Material Pretreatment (Critical)

1. Fermentation: Ferment fresh flowers in the dark for 3–15 days (or with a fermenting agent for 2–3 days) to improve extraction rate.

2. Drying: Low-temperature drying at 40–45℃, moisture content ≤8% (to prevent degradation/mold).

3. Grinding: 20–40 mesh (industrial) or 50–100μm (ultrafine), low-temperature grinding to prevent oxidation.

III. Mainstream Extraction Processes (by Industrialization Level)

Organic Solvent Extraction (Traditional mainstream, low cost)

Solvents: No. 6 solvent oil/petroleum ether (preferred), 95% ethanol, acetone Material-to-liquid ratio: 1:6–1:10 (w/v)

Temperature: 40–60℃, stirring extraction for 1–2 h, 2–3 times

Post-processing: Filtration → Concentration → Solvent removal → Crude oil extract (lutein ester 15–30%)

Yield: 85–92%

IV. Purification and Refining (Oil extract → High purity)

1. Saponification: 5–10% KOH ethanol solution, 60–70℃, 1–2 h, ester → Free lutein

2. Extraction: n-hexane/ethyl acetate, washing with water to remove alkali

3. Concentration/Solvent removal: Vacuum low temperature (≤50℃)

4. Refining:

Column chromatography (silica gel, n-hexane:ethyl acetate = 8:2)

Freezing crystallization (-10℃) → Crystals with a purity of ≥95%

Membrane separation (ceramic membrane + reverse osmosis) → Room temperature concentration, no heat loss

V. Industrial Production Line Configuration (Marigold)

Pretreatment: Fermentation tank → Low-temperature dryer → Crusher → Sieving

Extraction: Subcritical extraction unit/Multi-functional extraction tank

Separation: Plate and frame filter/Centrifuge → Ceramic membrane filtration

Concentration: Vacuum reduced pressure concentration (≤50℃)

Desolventizing: Thin-film evaporation/Stripping

Refining: Saponification tank → Extraction tower → Crystallization Reactor

Solvent Recovery: Recovery rate ≥95%

Material: SS304/316L, explosion-proof design

VI. Key Parameters and Yields

Dried Marigold: Lutein Ester 1.5–2.5%

Crude Oil: 15–35%, yield 85–97%

Free Lutein: ≥90% (food grade), ≥95% (pharmaceutical grade)

Total Yield: 80–90% (raw material → finished product)

VIII. Safety and Compliance

Solvents: No. 6 solvent, butane are flammable and explosive, requiring explosion-proof design.

Residue: Food grade ≤50ppm, pharmaceutical grade ≤10ppm

Regulations: Complies with GB 2760, USP, and EP standards.