Fennel Oleoresin Extraction Plant
Fennel Oleoresin Extraction Plant
Mechotech designs and manufactures industrial solvent extraction plants for Fennel Oleoresin, derived from Foeniculum vulgare seeds. The oleoresin is characterised by trans-anethole (60–80%), fenchone, and estragole (methyl chavicol), providing the characteristic sweet-anise aroma and flavour used extensively in food, confectionery, liqueur, and digestive supplement industries. Our plants deliver high trans-anethole yields with low-temperature processing that prevents isomerisation to the less desirable cis-anethole.
Mechotech's Fennel Oleoresin extraction plants use food-grade ethanol or hexane percolation at 35–50°C to co-extract the aromatic volatile oil fraction and the non-volatile fixed oil (petroselinic acid-rich) from ground fennel seeds. Strict temperature control below 55°C during evaporation prevents trans-to-cis anethole isomerisation and estragole decomposition. All systems comply with ATEX Zone 1, WHO-GMP, and FSSAI standards, and include GC-based quality control for trans-anethole specification.
Manufacturing Process
Raw Material Preparation
Dried fennel seeds (Foeniculum vulgare, moisture ≤10%) are cleaned using a vibratory de-stoner and air classifier to remove foreign matter. Seeds are cracked to 10–20 mesh to maximise anethole exposure to solvent while generating minimal ultra-fine meal that clogs filtration systems.
Solvent Extraction
Cracked fennel seed is loaded into SS 316L percolators and extracted with food-grade ethanol (95%) or hexane at 35–50°C. The miscella accumulates trans-anethole, fenchone, estragole, and petroselinic acid-rich fixed oil over 3–5 counter-current extraction stages. Total extraction cycle is 4–6 hours with continuous miscella recirculation.
Miscella Filtration
The pale-yellow aromatic miscella is filtered through a horizontal sparkler filter and then polished through 2-micron cartridge filters under nitrogen pressure. Filtration under nitrogen prevents anethole oxidation during the filtration hold period and maintains product colour in the finished oleoresin.
Evaporation & Concentration
Filtered miscella is concentrated in a falling-film evaporator operating at 45–55°C under vacuum (−0.08 MPa). A wiped-film evaporator completes solvent stripping to below 25 ppm residual. Temperature is strictly capped at 55°C to prevent trans-anethole isomerisation. Recovered solvent is condensed and recycled at >95% efficiency.
Standardization
Concentrated oleoresin is analysed by GC-FID for trans-anethole content, fenchone level, and estragole concentration. HPLC quantifies fixed oil fraction. Batches are blended to customer-specified trans-anethole content (60–80%) and adjusted for viscosity. GC isomer ratio (trans:cis anethole) is verified to meet EU flavouring specification limits.
Packing & Storage
Finished fennel oleoresin is filled into food-grade aluminium tins or HDPE drums under nitrogen blanketing. Anethole can crystallise at low temperatures (melting point 22°C), so storage at 15–25°C is recommended. Each container is labelled with batch number, GC profile, and COA reference for complete traceability.
Applications
- Food flavouring in breads, biscuits, sausages, fish products, and confectionery — the primary commercial application of fennel oleoresin globally
- Liqueur and spirits industry — anethole is the key flavour compound in anise-flavoured spirits including ouzo, pastis, arak, and sambuca
- Digestive aid and carminative supplement formulations in capsule, syrup, and infant gripe water preparations
- Confectionery flavouring in anise candies, liquorice-flavour products, and chewing gum base formulations
- Pharmaceutical flavour masking in oral liquid medicines and syrups where the sweet anise note improves palatability
- Personal care products including toothpaste, mouthwash, and breath fresheners leveraging anethole's antimicrobial properties
- Fragrance industry as a natural anise note ingredient in oriental and gourmand perfume compositions
- Functional food and herbal tea formulations for digestive comfort, lactation support, and antispasmodic benefit
Key Features
Trans-Anethole Integrity
Extraction and evaporation temperatures are kept below 55°C throughout the process to prevent isomerisation of the desirable trans-anethole to the less flavourful and potentially toxic cis-anethole. GC isomer ratio analysis of every batch verifies compliance with EU flavouring regulation limits for cis-anethole.
Explosion-Proof Design
All electrical installations in solvent-handling zones are ATEX Zone 1 / IECEx certified. Enclosed extraction vessels with nitrogen padding and continuous LEL monitoring at extraction, filtration, and evaporation areas ensure safe processing with ethanol or hexane.
Solvent Recovery System
A multi-effect falling-film evaporator with refrigerated condenser bank recovers over 95% of solvent per batch. A dedicated molecular sieve desiccant column maintains recovered ethanol purity at ≥95%, enabling direct reuse in subsequent extraction batches.
GMP Compliant Construction
SS 316L product-contact surfaces, hygienic tri-clamp fittings, and CIP spray assemblies support WHO-GMP, FSSAI Schedule 3, and EU GMP compliance. The plant layout provides a dedicated packing area with positive-pressure HEPA filtration to meet food-grade oleoresin standards.
Multi-Spice Platform
The extraction system handles sweet fennel, bitter fennel, anise seed, and star anise with minimal changeover — all anethole-rich spice sources processed on a common platform. CIP cleaning and percolator bed reconfiguration enable changeover within one production shift.
Frequently Asked Questions
What oleoresin yield can be expected from fennel seeds?
What is the permitted level of estragole in fennel oleoresin for food use?
Can the plant produce fennel oleoresin from both seeds and herb (leaf/stalk)?
What is the minimum order of plant capacity for fennel oleoresin production?
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