The Pigment Family: Chlorophyll a, Chlorophyll b, and What They Become

Healthy young wheatgrass owes its colour to two closely related pigments. Chlorophyll a is the dominant form — blue-green, the primary photosynthetic pigment — with chlorophyll b alongside, yellower-green, in a ratio of roughly 3:1 in healthy young grass. Both are built around a porphyrin ring holding a single magnesium ion at its centre, and that magnesium is the part of the structure that matters to a buyer, because it is the part that gets lost.

Pheophytin — chlorophyll after the damage

Under heat or acid, the magnesium ion is displaced by hydrogen and chlorophyll becomes pheophytin — the same molecule minus its centre, and grey-brown instead of green. Anyone who has overcooked green vegetables has watched this reaction. It is effectively irreversible in a food material, and it is the reason a wheatgrass powder's colour is a legitimate analytical statement: bright green means intact chlorophyll, which means young grass gently dried; olive or khaki means pheophytin, which means heat, age, or both.

The key insight: chlorophyll sits on a one-way degradation pathway, exactly as gingerols do in ginger — heat moves material along it and nothing moves it back. The chlorophyll figure on a wheatgrass CoA is therefore a permanent record of harvest stage and processing temperature, which is why it is the single number worth insisting on for a material that otherwise has no marker.

How Total Chlorophyll Is Measured

The standard method is UV-Vis spectrophotometry: the pigments are extracted into a suitable solvent and absorbance is read at the red-region maxima of chlorophyll a and b — around 663 nm and 645 nm respectively — with established equations converting the two readings into chlorophyll a, chlorophyll b and total chlorophyll. The method is fast, inexpensive and reproducible, which is why it is the industry's working assay for cereal-grass materials.

Its limitation is worth knowing: a simple total-absorbance reading does not by itself distinguish natural chlorophyll from added green colourants. A competent laboratory closes that gap by reading the full spectrum — natural chlorophyll shows the characteristic twin-peak a/b profile, while copper chlorophyllin, the common colour adulterant, shows a shifted spectrum — and, decisively, by checking copper by ICP-MS, since chlorophyllin carries copper where natural chlorophyll carries magnesium. An elevated copper line on a suspiciously vivid powder is a finished argument.

What Chlorophyll Levels Should You Expect?

The figure is format-dependent, which is precisely why it discriminates between formats:

MaterialTypical total chlorophyllWhy
Whole-grass powderNLT 0.5% w/wPigment diluted by the full fibre fraction
Cold-processed juice powderNLT 1.0% w/wFibre removed; solubles and pigments concentrate
High-chlorophyll gradeNLT 2.0% w/wSelected material, chlorophyll-forward processing
Mature / over-aged grassBelow young-grass figuresChlorophyll declines after jointing as stem and fibre build
Heat-abused materialLow, with olive-brown castChlorophyll converted to pheophytin

Read as a table, the assay does three jobs at once. A "juice powder" assaying at 0.5% is whole-grass powder wearing the wrong label. A whole-grass powder assaying well below 0.5% was cut late or dried hot. And a powder assaying implausibly high for its format and price deserves the copper check before applause.

Writing a Specification That Cannot Be Gamed

A wheatgrass specification that just says "green powder, rich in chlorophyll" leaves every door open. Close them like this:

  1. Name the format. "Cold-processed juice powder of Triticum aestivum young grass, fibre removed" — or whole-grass powder, stated as such. The format claim is the price claim.
  2. Set the chlorophyll minimum with its method. "Total chlorophyll NLT 1.0% w/w on dry basis, by UV-Vis." Without the method clause the number is unanchored.
  3. Require the harvest-stage declaration. Pre-jointing. The assay corroborates it; the declaration makes it contractual.
  4. Add a copper limit or copper-reported line. The cheapest chlorophyllin-spiking control available.
  5. State the dry basis and require carriers declared. Standard anti-dilution hygiene, as for any botanical powder.

Chlorophyll Keeps Degrading After Manufacture

The magnesium-loss reaction does not stop at the factory gate; it continues slowly at ambient temperature and accelerates with light exposure, which bleaches chlorophyll directly. A wheatgrass lot that assayed comfortably at release can drift downward through a hot, bright warehouse season. If you hold stock against a chlorophyll specification: below 25°C, dark, sealed with the liner intact — and re-assay before use if a lot has sat through a summer in an uncooled facility. The same logic applies inside your own process: hot-fill steps, gummy depositing and aggressive spray-drying all take a visible toll, so assay the finished product, not only the incoming powder.

SV Botanica declares total chlorophyll by UV-Vis on every wheatgrass grade, verifies the a/b spectral profile for identity, and monitors copper by ICP-MS. See the wheatgrass extract product specification for the full parameter list, or the wheatgrass buyer's guide for how the format taxonomy shapes the purchase.