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Coriander Processing PLANT

Coriander is India’s most widely consumed spice powder — and one of the most technically underestimated to process correctly. The seed carries 0.2–1.5% volatile oil containing linalool, geranyl acetate and terpinene — the compounds responsible for its characteristic aroma. Every stage of the processing line from cleaning through to packing either retains or depletes these compounds. MillNest designs coriander processing lines around aroma retention, fineness specification and the specific seed variety being processed.

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All Process Solutions

Volatile oil retention

Low-heat aroma-protective grinding

Fineness from coarse to 80 mesh

coriender
CHILLI VARIETIES WE can help you PROCESS
Different seeds, different processing requirements
Indian coriander varieties differ in seed size, oil content, aroma profile and moisture behaviour — all of which affect how the grinding line needs to be configured. The same rotor speed and screen aperture will give different results on Eagle 65 versus CO-4.

Eagle 65 (Rajasthan)

Large bold seed, high volatile oil content. Premium aroma grade. Primary export variety. Processed for whole seed, coarse powder and fine powder.

Rajendra Swati (UP/MP)

Medium seed, moderate oil. High-yield variety suited to large-scale commercial powder production. Good aroma-to-yield balance.

CO-4 (Tamil Nadu)

Small round seed, lower oil content than northern varieties. Suited for domestic powder use. Requires different grinding configuration due to smaller seed diameter.

Hisar Sugandh (Haryana)

High volatile oil content, distinctive aroma. Developed for oil extraction and premium powder. Lower yielding but higher value per tonne.

Split Dhaniya (Roasted)

Pre-roasted split seed for sambar and curry powder blends. Roasting changes the grinding character significantly — requires post-roast trial before mill configuration.

Export Blended Grades

Multi-variety blends to hit buyer specifications for volatile oil content, colour value (L*a*b*) and fineness. Standard for export powder contracts.

Dhani (Himachal)

Small, thin-walled. High volatile oil content. Processed for local powders and pickles. Low throughput applications.

Blended Grades

Multi-variety blends to hit target ASTA, moisture and capsaicin specifications. Common in export and branded powder lines.

HOW IT WORKS
The coriander processing line, stage by stage

Volatile oil loss is cumulative — each stage where heat, friction or prolonged exposure occurs reduces the aroma value of the finished powder. The line design must manage temperature at every transfer point, not just in the mill itself.

STEP 1
Intake & Cleaning
Stones, dust, stems and light impurities removed
STEP 2
Aspiration & Grading
Air separation of lightweight material and sizing by seed diameter
STEP 3
Destoning
Gravity table removes stones that protect mill screens
STEP 4
Moisture Conditioning
Seed moisture adjusted to target before milling
STEP 5
Primary Milling
Coarse reduction — seed cracked to coarse powder
STEP 6
Secondary Milling
Intermediate reduction to target fineness
STEP 7
Sifting
On-spec powder separated — oversize returns to mill
STEP 8
Blending
Variety blending for aroma and colour specification
STEP 9
Metal Detection & Packing
Metal detector, auto-weigher, fill-seal or bulk bag
KEY QUALITY PARAMETERS
What buyers actually measure
Coriander powder is traded on aroma, fineness, colour and moisture. The processing line determines the outcome on all four — not the raw material alone.

Volatile Oil Content

Target: 0.3–1.0 ml/100g for premium grades
The single most important quality parameter for export and industrial coriander powder. Volatile oil is measured by steam distillation. High oil content commands a price premium. Hammer mill grinding generates more heat than pin mill grinding, which can reduce volatile oil content — equipment selection and cooling configuration both affect the final oil yield in the powder.

Colour Value (L*a*b*)

Specification: L* 60–75, positive a* and b*
Coriander powder colour ranges from pale yellowish-green in fresh, well-processed powder to brownish-beige in over-milled or poorly stored material. Excessive heat during grinding increases the browning index measurably. Moisture content at the time of milling, rotor speed and the number of passes through the mill all affect final colour. Export buyers specify L*, a* and b* colour values for premium grades.

Fineness (Mesh / Particle Size)

Common grades: 30, 40, 60, 80 mesh
Fineness specification is set by the end application — 30–40 mesh for household powder, 60 mesh for branded spice blends, 80 mesh for masala premix use. Coriander's relatively hard seed hull means it requires more grinding energy per unit output than soft spices. Screen wear is a consistent problem on high-throughput coriander lines — particle size monitoring at regular intervals is essential to catch drift before it reaches the buyer.

Moisture Content

Specification: typically 10% max (AGMARK)
Moisture in the incoming seed directly affects grinding behaviour and volatile oil retention. Seeds above 12% moisture grind poorly — they smear rather than fracture — and the milling temperatures are higher for the same output. Seeds below 8% are brittle but generate excessive fines. Moisture conditioning to the target range before the mill is one of the most controllable steps for protecting volatile oil and achieving consistent fineness output.

Foreign Matter & Extraneous Material

AGMARK: ≤1% total extraneous matter
Stones that reach the mill damage screens and generate metallic contamination. Stems and foreign seeds reduce aroma quality per unit weight and introduce colour variation. Effective cleaning — aspiration, destoning, magnetic separation — before the grinding stage protects mill internals and improves the uniformity of the ground powder. Cleaning quality also directly affects compliance with AGMARK and FSSAI standards for exported coriander powder.

Microbial Load

EU/US import: TPC typically <10⁵ CFU/g
Field-dried coriander seed carries microbial contamination from soil contact, open storage and handling. Export markets — particularly EU and US — apply microbial limits to imported coriander powder and will reject shipments without validated treatment records. Natural steam pasteurization at temperatures below 100°C treats coriander with lower risk to volatile oil than full sterilization, preserving aroma compounds while meeting export microbial requirements.

EQUIPMENT BY PROCESS STAGE
Machines MillNest deploys on this line
Each stage of a coriander processing line has a specific equipment requirement. The complete line integrates all stages — each configured around the specific seed variety and output specification.Each row below pairs a process solution with the specific equipment used in fertilizer powder applications. Click either side to go deeper.
Stage 1 — Cleaning & Pre-Treatment

Stone removal, aspiration and moisture conditioning

Coriander arrives from farm with stones, dust, stems, weed seeds and variable moisture. Stones reaching the mill damage screens and generate metallic contamination in the product — destoning before the grinding section is mandatory, not optional. Aspiration removes lightweight material and improves the consistency of what enters the mill. Moisture conditioning to 8–11% before milling balances volatile oil retention against grinding energy: too dry and brittle seeds generate excessive fines; too moist and the material smears on screens and loses aroma to heat faster.
View Material Handling Solutions
Equipment at this stage
BELT

Belt Conveyor & Bucket Elevator

Seed intake, elevation to cleaning section — continuous controlled feed rate to the processing line

ASPIR

Aspirator & Cyclone

Air separation of dust, stems and lightweight foreign material before seed reaches the grinding section

Stage 2 — Two-Stage Milling

Aroma-protective size reduction with controlled heat

Coriander seed has a hard outer hull that requires meaningful impact energy to fracture, but the volatile oil it carries begins evaporating the moment the seed breaks open. This makes grinding temperature management the central design challenge on a coriander line. MillNest configures two-stage hammer milling — primary coarse reduction, secondary fine reduction — with pneumatic inter-stage transfer that dissipates heat between passes. Rotor speed, screen aperture and air-to-material ratio are all set from trial data on the specific seed batch. For premium export grades or oleoresin extraction material, inter-stage cooling can be added to keep powder temperature below 40°C through the full milling sequence.
View MHAM Hammer Mill
Equipment at this stage
MHAM

Hammer Mill (×2 stages)

Primary and secondary size reduction — low-heat rotor configuration, interchangeable screens for fineness grades

MUNI

Universal Mill

Alternative for fine or export grades — multi-mode milling allows impact vs shear selection to optimise volatile oil retention

PNEU

Pneumatic Inter-Stage Transfer

Heat dissipation between milling stages — prevents cumulative temperature build-up across the grinding sequence

Stage 3 — Microbial Treatment (Export Lines)

Low-temperature pasteurization for volatile oil preservation

For export-grade coriander powder destined for EU, US and Middle East markets, documented microbial treatment is a procurement requirement. Coriander, unlike chilli, is heat-sensitive enough that full HTST sterilization at 102–122°C risks meaningful volatile oil loss. MillNest deploys TEMA Process B.V. pasteurization at temperatures below 100°C — sufficient to meet export microbial specifications while preserving a greater proportion of the volatile oil fraction. The specific temperature and treatment time are determined from the incoming microbial count of the raw material, not set as a standard programme.
View Pasteurization Solution
Equipment at this stage
PAST

Natural Steam Pasteurizer

Below 100°C treatment — pathogen reduction with lower volatile oil loss than full sterilization temperatures

FBD

Fluid Bed Dryer

Post-pasteurization moisture removal — controlled drying to target moisture before milling or packing

Stage 4 — Sifting, Blending & Packing

Specification control and variety blending for consistent aroma grade

Sifting after the final milling stage ensures only on-specification material proceeds — oversize is returned to the secondary mill rather than diluting the fineness of the finished batch. For lines producing multiple mesh grades from a single seed source, the sifter deck configuration is changed between runs. Ribbon blending combines different seed varieties or production batches to hit a specified volatile oil content or colour value for branded and export coriander powder contracts — similar to chilli blending for ASTA specification. Prompt sealed packing after blending is the final step in protecting volatile oil from evaporation loss before the product reaches the consumer.

View MRBL Ribbon Blender
Equipment at this stage
SIFT

Rotary Sifter

Particle size separation — on-spec powder to blending, oversize returned to secondary mill

MRBL

Ribbon Blender

Variety blending to volatile oil and colour specification — load cell weighing, sealed discharge to packing

Protect aroma. Achieve consistent fineness.
Tell us your processing goals.

Coriander’s essential oils are sensitive to excessive grinding temperatures. Share your product specifications and production targets, and MillNest will design a processing line that helps retain aroma while delivering the particle size your market demands.

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