Anthocyanins
Also written anthocyanin
Quick answer
The red-to-purple-to-blue pigment family, and the only colour in this catalogue that changes with acidity — which is why a shiso pickle turns scarlet and a red cabbage turns blue.
What it does
Anthocyanins are a family rather than a single compound, and the record is named in the plural deliberately: cyanidin, delphinidin and their relatives differ, and the spices here do not distinguish between them. What they share is the property that makes them worth a page — their colour depends on pH. In acid they are red, at neutral they are purple, in alkaline conditions they shift towards blue and green. They also carry a mild astringency, which is part of why the fruits that hold them taste as they do.
How it behaves when cooked
Four properties of the molecule, and what they mean at the stove.
- Volatility
- low
- Fat solubility
- low
- Water solubility
- high
- Heat stability
- low
Two properties govern everything: they are water-soluble and their colour answers to acid. Being water-soluble, they leach — a sumac or a barberry simmered in a stock colours the stock rather than the dish, which is why both are usually scattered on at the end. Being pH-sensitive, they are the one pigment a cook can deliberately steer: red shiso leaves packed with salt and umeboshi turn a vivid scarlet because the plum brine is acidic, and the same leaf in a neutral dish stays a dull purple. That is a technique rather than an accident, and it is the mechanism behind the colour of Japanese pickles. They also degrade with sustained heat, so a long-cooked anthocyanin dish goes brown — the reason barberries are added to a rice dish near the end rather than cooked through it.
Spices that carry it
Recorded on the compound rather than on each spice, so the two cannot disagree.
- BarberryPrincipal component
The jewel red of zereshk polo, which is lost if the berries are cooked through the rice rather than added late.
- ShisoPrincipal component
Red shiso is the clearest culinary demonstration of the pH effect anywhere: the leaf is dull purple until it meets the acid of umeboshi brine, and then it is scarlet.
- SumacPrincipal component
The deep red, and the reason sumac is scattered over a finished dish rather than cooked into it.
- KokumMajor component
Not to be confused with
Compounds a reader is likely to take for this one, and why they differ.
Capsanthin
The other red in this catalogue, and the opposite in every practical respect: capsanthin is a fat-soluble carotenoid indifferent to pH, anthocyanins are water-soluble and answer to acid. Substituting one red spice for another without knowing which pigment is involved is how a dish ends up the wrong colour.
Betalains
The pigment of beetroot, frequently assumed to be an anthocyanin and chemically unrelated. It is not pH-responsive in the same way, which is why beetroot does not do the shiso trick.
Questions this page answers
- what is anthocyanins
- what does anthocyanins do
- which spices contain anthocyanins