Skins - Red Onions
Skins - Red Onions
Mechotech designs and manufactures turnkey natural colour extraction plants for red onion skins. In the Mechotech catalogue, Skins - Red Onions is listed in the Green Colour group alongside Flowers - Tea Tree / Yarrow / Black Eyed Susans, Leaves - Spinach / Chamomile / Nettle and Plant - Larkspur / Dyer’s Broom. No Mechotech article, case study or legacy page describes red onion skins or a green shade from them: the pigment, the shade and the extraction route are not stated in any source, so they are confirmed with the client before the plant is configured. Mechotech’s articles on brown onion skins describe quercetin flavonoids in the skins of Allium cepa and a yellow to orange range; they do not describe red onion skins. This page is separate from the brown onion skin page.
Mechotech’s Skins - Red Onions plant is configured around the raw material and the target colour extract. It is built in SS 316L with integrated solvent recovery, automation and full documentation, and is delivered as a commissioned turnkey system. Because no Mechotech source describes red onion skin pigments or a green colour route, the line is specified generically for solid-liquid extraction, filtration, vacuum concentration and standardisation, and the solvent system, extraction conditions and pH are established during process development and pilot validation on the client’s skins.
Technical Specifications
| Product | Skins - Red Onions Natural Colour Extraction Plant |
|---|---|
| Raw Material | Red onion skins (catalogue name: Skins - Red Onions) |
| Botanical Name | Not stated for red onion in any Mechotech source; Mechotech’s brown onion skin articles name Allium cepa |
| Plant Part / Feed Form | Skins, as named in the catalogue; cleaned and screened before extraction; exact feed form confirmed with the client |
| Colour Group | Green Colour (see the Green Colour page) |
| Colour-forming Components | Not stated in any Mechotech source; the pigment and the target shade are confirmed with the client and established during process development |
| Process Category | Natural Colour Extraction Plants |
| Extract Type | Natural colour extract (liquid concentrate or dried powder, per specification) |
| Extraction Method | Closed jacketed SS 316L extraction at controlled temperature; solvent system (water, alcohol / aqueous or other) and conditions confirmed during process development |
| Product-contact Material | SS 316L |
| Filtration System | Plate-and-frame filter press with cartridge polish filters |
| Concentration System | Falling-film / vacuum evaporator with solvent recovery where a solvent is used |
| Drying System | Spray or vacuum dryer, where a powder is required |
| Automation | PLC-based |
| Plant Capacity | Configured to requirement |
| Utility Requirements | Steam, chilled/cooling water, compressed air and power (project-specific) |
| Compliance | GMP hygienic design; full documentation for qualification |
| Final Product Form | Natural colour extract (green colour group) |
Plant Capacities
| Plant Scale | Raw Material Throughput | Typical Use |
|---|---|---|
| Pilot | Configured to your feedstock and trial plan | Product development, parameter validation |
| Semi-Commercial | Configured between pilot and commercial scale | Scale-up trials, contract manufacturing |
| Commercial | Configured to raw-material supply and confirmed buyer volume | Commercial production |
Capacity is configured to raw-material supply, confirmed buyer volume and investment timeline; a pilot plant is recommended to validate parameters before scaling.
Manufacturing Process
Raw Material Preparation
Red onion skins are collected, screened to remove soil and onion flesh, cleaned, tested for moisture and, where required, size-reduced so the extraction liquor can reach the tissue; the feed form is set during process development.
Extraction
The prepared skins are extracted in closed jacketed SS 316L vessels at controlled temperature over several cycles. The solvent system, temperature and pH are not described by any Mechotech source for red onion skins and are set during process development.
Filtration
The extract is separated from the spent skins and clarified through a plate-and-frame filter press followed by cartridge polish filters.
Concentration & Solvent Recovery
The extract is concentrated in a falling-film / vacuum evaporator, with solvent recovered through the condenser return system where a solvent is used.
Standardisation
The concentrate is assayed and adjusted to the declared target colour specification, such as shade and colour strength. The shade and pigment strength are established in trials.
Drying & Quality Control
The standardised extract is supplied as a liquid concentrate or spray- or vacuum-dried to a powder, per specification, then released after assay, residual-solvent (where a solvent is used), heavy-metal, microbial and moisture testing.
Major Plant Equipment
- Raw material cleaning, authentication and moisture testing
- Size-reduction system
- Closed jacketed SS 316L extraction vessels
- Solvent storage tanks
- Plate-and-frame filter press
- Cartridge polish filtration
- Falling-film / vacuum evaporator
- Solvent recovery unit and condensers
- Standardisation / blending vessel
- Spray or vacuum dryer
- CIP system
- Automation and instrumentation
Plant Output
Applications
- Natural colour and dye ingredient supply
- Cosmetic and personal-care colour applications (subject to the shade obtained)
- Food colour applications (subject to approval of the specific colour in each market)
Key Features
SS 316L Construction
Electropolished SS 316L product-contact surfaces with CIP operation between batches.
Route Set on the Client’s Skins
No source describes red onion skin pigments, so solvent, conditions and shade are established on pilot runs with the client’s material rather than assumed.
Closed-Loop Solvent Recovery
Where a solvent is used, integrated condenser-return recovery reuses solvent between batches and reduces solvent loss.
Standardised to Specification
In-process and batch-release assay are used to check the finished extract against the agreed target specification, such as shade and colour strength.
Scalable Batch Capacity
Plants are configured to requirement from pilot scale upward, with modular expansion.
Frequently Asked Questions
Does Mechotech supply the complete machinery for Skins - Red Onions?
What specification can the Skins - Red Onions plant achieve?
What production capacities are available for the Skins - Red Onions plant?
Which industries use the Skins - Red Onions plant?
Which pigment and which shade does this page cover?
Is this the same as the brown onion skin page?
Why is a red onion entry in the Green Colour group?
How is the extraction route chosen without a source?
Where does this page sit in the Green Colour range?
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