Rosemary Solvent Extraction Plant
Spices Oleoresin Extraction Plants

Rosemary Solvent Extraction Plant

Rosemary Solvent Extraction Plant

Rosemary Solvent Extraction Plant

Mechotech designs and manufactures industrial rosemary solvent extraction plants for production of standardised rosemary antioxidant extract from Salvia rosmarinus (formerly Rosmarinus officinalis). Rosemary extract — standardised for carnosic acid (2–5%), rosmarinic acid, carnosol, and ursolic acid — is one of the most commercially important natural antioxidants globally, used for food preservation, cosmetic anti-aging formulations, nutraceuticals, and pharmaceutical applications. Our ethanol-based extraction plants are available in batch capacities from 100 kg to 5,000 kg dry rosemary herb per cycle, with GMP construction and FSSAI, EU, and FDA-compliant process design.

Rosemary antioxidant extract (RAE) works by two distinct mechanisms: the lipophilic diterpenoids (carnosic acid and carnosol) act as hydrogen-atom-transfer antioxidants in fat-phase applications such as edible oils and meat products; rosmarinic acid and other phenolic acids provide complementary aqueous-phase antioxidant activity for water-containing applications. Mechotech's extraction plants use ethanol as the primary solvent for broad-spectrum extraction of both lipophilic and hydrophilic antioxidant fractions, followed by concentration and standardisation to defined carnosic acid content. For specialised lipophilic antioxidant applications (meat and oil preservation), optional hexane defatting or winterisation steps are included. All plants are designed to food-safety and pharmaceutical GMP standards.

Manufacturing Process

1

Plant Material Preparation & Standardisation

Dried rosemary leaves and flowering tops (Salvia rosmarinus) are sourced, inspected for origin, freedom from mould, pesticide residues (EUREPGAP or organic certification preferred), and carnosic acid content by HPLC (commercial dried rosemary typically contains 1.5–3.5% carnosic acid, 0.5–2.0% carnosol, and 0.5–1.5% rosmarinic acid on a dry weight basis). Material is milled to 1–3 mm particle size. Batch weight is standardised based on carnosic acid assay, targeting a consistent carnosic acid input per extraction cycle.

2

Acid Extraction — Ethanol-Based Extraction

Milled rosemary is loaded into jacketed SS 316L extraction vessels and extracted with 60–96% food-grade ethanol at 50–65°C for 2–3 hours under agitation at a 6:1 to 10:1 solvent-to-herb ratio (v/w). Higher ethanol concentration (90–96%) preferentially extracts the lipophilic carnosic acid and carnosol; lower concentration (60–70% ethanol) also co-extracts rosmarinic acid and other polar phenolics. Two or three extraction stages with fresh solvent maximise total antioxidant extraction efficiency to greater than 80% of theoretical content. Combined extracts are filtered through a leaf filter and cartridge polishing filters.

3

Basification — Not Required; Decolouration

Rosemary extraction does not require acid-base treatment (carnosic acid is a neutral diterpene phenol, not a basic amine). Instead, the filtered ethanol extract undergoes activated carbon treatment (1–3% w/v) at 50°C for 30 minutes to remove chlorophylls, carotenoids, and other coloured pigments that would produce a dark green-brown finished extract unacceptable for food-use applications. After hot filtration through a polishing cartridge, the clear, pale yellow to light amber ethanol extract proceeds to evaporation.

4

Solvent Extraction — Liquid-Liquid Fractionation (Optional)

For specialised lipophilic rosemary antioxidant (for use in oils and fats), the concentrated ethanol extract is optionally partitioned against hexane to selectively transfer carnosic acid and carnosol into the hexane phase while leaving more polar phenolics in the ethanol-water phase. The hexane phase is evaporated to yield a concentrated, lipophilic rosemary extract standardised for carnosic acid. For general-purpose rosemary antioxidant (combining both lipophilic and hydrophilic antioxidants), this fractionation step is omitted and the ethanol extract is directly concentrated.

5

Evaporation & Standardisation

Filtered (and optionally fractionated) ethanol extract is concentrated in a falling-film vacuum evaporator at 45–50°C and 60–80 mbar to recover ethanol (>95%) and produce a concentrated rosemary extract paste. The paste is assayed by HPLC for carnosic acid content. Standardisation to the target specification — typically 2% or 5% carnosic acid for commercial food-grade antioxidant, or 10–20% for cosmetic-grade antioxidant — is achieved by blending the concentrated extract with excipients (sunflower oil, maltodextrin, or silica) to achieve the target assay before spray drying.

6

Spray Drying (Optional) & QC

For dry powdered rosemary extract (for capsule, tablet, and dry food application), the standardised extract concentrate is spray-dried with a maltodextrin or silica carrier. For oil-dispersible rosemary antioxidant (for edible oil and meat applications), the concentrated extract is dissolved in sunflower or soybean oil at the target concentration and filled into drums. QC testing covers HPLC assay for carnosic acid (target 2–20% depending on grade), rosmarinic acid, carnosol; DPPH radical scavenging activity (antioxidant capacity, EC50 value); colour (Gardner scale for oil solutions); heavy metals by ICP-MS; pesticide residues; and microbial counts.

Applications

  • Natural food antioxidant — rosemary extract approved under EU Regulation (EU) No 1129/2011 (E392), FSSAI, and FDA (GRAS) as a food additive for prevention of oxidative rancidity in edible oils, meat products, poultry, fish, snacks, and butter at 0.02–0.1% concentration
  • Edible oil stabilisation — rosemary antioxidant mixed into refined vegetable oils (sunflower, corn, soybean) to extend shelf life by inhibiting lipid peroxidation and off-flavour development during storage and cooking
  • Meat and processed food preservation — rosemary extract used in sausages, cured meats, ground beef, and poultry to replace synthetic antioxidants (BHA, BHT) with a clean-label natural alternative
  • Cosmetic anti-aging formulations — carnosic acid and rosmarinic acid used in anti-aging serums, face oils, and sunscreens for their UV-protective, anti-inflammatory, and free radical scavenging properties at 0.1–1%
  • Nutraceuticals and dietary supplements — rosemary extract standardised for carnosic acid marketed for cognitive health (Bacopa-like memory-enhancement claims), anti-inflammatory, and antioxidant supplement use
  • Pharmaceutical research — rosemary diterpenes investigated for neuroprotective, anticancer, and antimicrobial activities in academic and industrial pharmacological research
  • Hair care and personal care — rosmarinic acid-rich rosemary extract used in hair growth serums, anti-dandruff shampoos, and scalp treatments for its documented DHT-inhibiting and blood circulation-promoting properties

Key Features

  • Carnosic Acid-Optimised Extraction Conditions

    Carnosic acid is the primary commercial marker of rosemary antioxidant extract quality and is sensitive to oxidation and thermal isomerisation to carnosol above 60°C. Mechotech's extraction conditions — ethanol concentration at 90–96%, temperature controlled at 50–65°C, and sub-50°C vacuum evaporation — are specifically optimised to maximise carnosic acid extraction and minimise its conversion to carnosol or other oxidation products during processing.

  • Activated Carbon Decolouration for Food-Grade Clarity

    Crude rosemary ethanol extract is dark green from co-extracted chlorophylls — unacceptable for food antioxidant applications where the product is added to light-coloured oils and food products. Mechotech's activated carbon decolouration system (batch treatment with hot filtration) removes chlorophylls, pheophytins, and other coloured pigments to produce a pale to light amber extract that complies with food additive colour specifications.

  • GMP SS 316L Construction for Food and Pharma

    All product-contact equipment is fabricated in SS 316L with electro-polished surfaces, food-grade gaskets, and CIP cleaning systems. The plant meets FSSAI food processing GMP standards, EU Food Safety norms for E392 rosemary extract manufacture, and ISO 22000 food safety management requirements, enabling export of rosemary antioxidant to European and US food ingredient markets.

  • Closed-Loop Ethanol Recovery (>95%)

    Food-grade ethanol is the most expensive input in rosemary extraction. Mechotech's falling-film evaporation system recovers greater than 95% of ethanol per batch, tested for concentration (target 94–96% v/v) before recycling. This recovery efficiency directly determines the operating economics of the plant and is a key differentiator in Mechotech's design.

  • Lipophilic and Hydrophilic Grade Production from Single Plant

    The same extraction plant can produce both lipophilic rosemary antioxidant (high carnosic acid, for oil-phase food applications, using anhydrous ethanol extraction with optional hexane fractionation) and hydrophilic rosemary antioxidant (higher rosmarinic acid, for aqueous food and cosmetic applications, using 60–70% aqueous ethanol without fractionation) by adjusting solvent composition and the optional liquid-liquid fractionation step.

Frequently Asked Questions

What is carnosic acid and why is it the key quality marker for rosemary antioxidant extract?
Carnosic acid (C20H28O4) is a diterpene phenol and the primary lipophilic antioxidant compound in rosemary (Salvia rosmarinus), typically constituting 1.5–3.5% of dried rosemary herb weight. It has exceptionally high DPPH radical scavenging capacity and, uniquely, acts as a suicide substrate antioxidant — it neutralises free radicals and reactive oxygen species at the cost of its own oxidation to carnosol and other quinones, progressively bleaching colour while preserving the fat or food product. Carnosic acid content is the commercial specification marker for rosemary antioxidant extract because it has the highest antioxidant potency, is specific to rosemary (unlike rosmarinic acid, which is found in many Lamiaceae herbs), and its concentration is directly correlated with antioxidant performance in edible oil shelf-life tests.
What EU and FSSAI regulations govern rosemary extract as a food additive?
In the European Union, rosemary extracts are approved as food additive E392 under EU Regulation (EC) No 1333/2008 and Commission Regulation (EU) No 1129/2011 for use in a wide range of food categories at specified maximum use levels (e.g., 100–400 mg/kg as carnosic acid in fats and oils; 50–200 mg/kg in meat products). In India, rosemary extract is permitted under FSSAI Food Safety and Standards (Food Products Standards and Food Additives) Regulations and is classified as a natural antioxidant. GRAS status in the USA (FDA 21 CFR 182.20) applies to rosemary oleoresin for antioxidant use. Mechotech's QC documentation supports compliance with all three regulatory frameworks for food antioxidant applications.
What is the expected carnosic acid yield from a kilogram of dried rosemary?
Commercial dried rosemary herb typically contains 1.5–3.5% carnosic acid (15–35 g per kg of dried herb). With Mechotech's extraction system achieving 80–85% extraction efficiency: from 1 kg dried rosemary at 2.5% carnosic acid, expect approximately 20–21 g of carnosic acid in the extract. To produce a standardised 5% carnosic acid dry extract powder, with spray-drying excipient at 1:1 ratio (extract:carrier), the yield from 1 kg rosemary would be approximately 400–420 g of standardised 5% carnosic acid powder. Actual yields depend on raw material quality, extraction efficiency, and carbon decolouration losses.
Can Mechotech's rosemary extraction plant be certified organic and what does that require?
Yes, the same plant can produce organic-certified rosemary extract, provided: (1) the raw rosemary herb is organically certified (NPOP, EU Organic, or USDA NOP, depending on target market); (2) the extraction solvent is food-grade ethanol from organic sources or approved solvents under the applicable organic standard (EU Organic permits ethanol and CO2 as processing solvents for organic extracts; water and ethanol are the primary permitted solvents); and (3) the facility has a valid organic processing certification from an accredited body (APEDA-recognised certification body for NPOP in India). Mechotech's plant design uses only ethanol and water as process solvents, making it fully compatible with organic processing certification requirements.

Ready to discuss your project?

Get a free quote and technical consultation from our engineering team.

Get A Free Quote
★Review Us