Green is one of the hardest colours to hold onto naturally. Cooked spinach turns olive-brown, matcha drinks fade to a dull khaki within weeks, and mint-flavoured confectionery loses its vivid shade long before it loses its taste. Natural chlorophyll food colour exists to solve exactly this problem, and the way it does so involves one of the more elegant pieces of food chemistry in the colour additive world: swapping a single metal atom.
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Why Plain Chlorophyll Doesn’t Hold Up
Chlorophyll is the pigment behind photosynthesis in every green plant, extracted commercially from sources like nettles, alfalfa, spinach, and grass. In its natural state, the chlorophyll molecule holds a magnesium atom at its centre - and that magnesium is precisely what makes the colour unstable. Heat and acid both strip it out during processing, which is why cooked or acidified green vegetables so reliably turn a duller olive-brown. A colourant made from unmodified chlorophyll inherits the same weakness.
E140: The Direct Extract
E140 is produced by direct solvent extraction of chlorophyll from plant material, and comes in two forms depending on the target application:
- E140(i) - chlorophylls, the oil-soluble, waxy form suited to fat-based products.
- E140(ii) - chlorophyllins, produced by saponifying the solvent-extracted chlorophyll, yielding a water-soluble powder for aqueous formulations.[1]
E140 delivers an authentically “natural” green shade, but it remains vulnerable to the same heat and acid instability as chlorophyll in its native plant form - a real limitation for processed foods that go through pasteurisation, baking, or long shelf-stable storage.
E141: The Stabilised Copper Complex
E141 solves the stability problem directly by replacing chlorophyll’s central magnesium atom with a copper ion. The resulting copper-chlorophyll complex holds its green colour dramatically better through heat, light, and acidic conditions than the unmodified pigment - which is why E141, not E140, is the form most processed food and beverage manufacturers actually reach for when colour stability through a full production and shelf-life cycle matters.[2] Like E140, it splits into two subtypes:
Designation | Form | Solubility |
E141(i) | Copper complexes of chlorophylls | Oil-soluble |
E141(ii) | Copper complexes of chlorophyllins | Water-soluble (commonly sold as sodium or potassium copper chlorophyllin) |
Regulatory Status
Both E140 and E141 are authorised food colours in the EU under Regulation (EC) No 1333/2008, with permitted use levels varying by food category as set out in Annex II of that regulation.[3] The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has set an acceptable daily intake for copper chlorophylls of 0–15 mg per kg body weight, a threshold unlikely to be approached under normal dietary use given the low inclusion rates typical in finished products.[4] In the US, sodium copper chlorophyllin is permitted for specific applications under FDA regulations, though the exact approved use categories differ from the EU’s broader Annex II authorisation, so manufacturers exporting across both markets need separate compliance checks rather than assuming one approval covers the other.
Choosing Between E140 and E141
The decision usually comes down to how much processing stress the final product will undergo:
- Fresh, minimally processed, or short shelf-life products - E140 often suffices, and appeals more directly to formulators avoiding any metal-complexed additive on the label.
- Pasteurised, baked, or long-shelf-life products - E141’s copper stabilisation earns its place, holding a consistent green through conditions that would fade E140 within days or weeks.
- Acidic beverages (fruit-flavoured drinks, some functional beverages) - E141 again, since acid is one of the fastest ways to strip magnesium from unmodified chlorophyll.
Manufacturers building a broader natural colour portfolio typically pair chlorophyll-based greens with other pigment systems - food colourants in the orange-yellow range, for instance - to cover a full shade spectrum without reaching for synthetic dyes.
Extraction and Sourcing Considerations
Because chlorophyll content and stability vary by source plant, harvest timing, and post-harvest handling, manufacturers sourcing chlorophyll colour extracts should confirm the plant source (spinach, alfalfa, and nettle yield slightly different shade characteristics), the extraction solvent used, and - critically for E141 - the copper content per batch, since this must stay within regulatory limits per serving, not just per raw ingredient. Suppliers running broader CO2 extraction and polyphenol extraction operations across multiple plant colourants tend to offer more consistent batch documentation than single-ingredient specialty suppliers.
Applications Beyond Straight Colouring
Chlorophyll-based colours extend into supplement and functional food formulations too, where “green superfood” positioning adds marketing value alongside colouring - overlapping with broader fortified foods formulation work. Beverage manufacturers have driven much of the recent growth in E141 demand, as matcha, tea extracts, mint, and “green juice” drinks all need a colour that survives bottling, pasteurisation, and shelf life without fading toward brown.
Why Buffalo Extraction Systems Fits In
Chlorophyll’s biggest processing risk is heat: too much of it during extraction, and the pigment starts degrading before it even reaches the copper-stabilisation step used to produce E141. Buffalo Extraction Systems’ CO2 extraction platforms are designed to run at controlled, comparatively low temperatures with precise pressure regulation, which matters directly for chlorophyll processors trying to preserve pigment integrity through extraction rather than relying entirely on downstream stabilisation to compensate for a rougher processing method. Their CO2 recirculation systems also support the kind of consistent, cost-managed operation that colour manufacturers need when running high extraction volumes for beverage-scale demand.
Frequently Asked Questions
What’s the difference between E140 and E141 chlorophyll colours? E140 is direct chlorophyll extract, retaining the natural magnesium centre and remaining vulnerable to heat and acid fading. E141 replaces that magnesium with copper, producing a far more heat- and acid-stable green.
Is copper chlorophyllin (E141) safe to consume? Regulatory bodies including EFSA and JECFA have assessed it as safe within established intake limits, and typical food and beverage inclusion levels sit well below the acceptable daily intake threshold.
Why does cooked spinach turn brown instead of staying green? Heat and acid strip the magnesium atom from natural chlorophyll, degrading the pigment. This is the exact instability problem E141’s copper substitution is designed to prevent in processed foods.
Which chlorophyll colour form should I use for a beverage application? For most beverages, the water-soluble forms - E140(ii) chlorophyllins or, for better stability through pasteurisation and shelf life, E141(ii) copper chlorophyllins - are the standard choice.
The Takeaway
Chlorophyll gives food and beverage manufacturers a genuinely natural route to green, but the choice between E140 and E141 - and between the oil- and water-soluble subtypes of each - is what determines whether that green actually survives to the point of sale. Match the form to the processing conditions and target shelf life, and natural chlorophyll colour performs reliably; get the mismatch wrong, and even the best-sourced extract fades faster than the product it’s meant to colour.
