What is pullulan?
Pullulan is a natural polysaccharide formed by the fungus Aureobasidium pullulans when it ferments starch, for example from tapioca. It is used as a vegan capsule shell and is authorised in the EU as the additive E 1204.
What is pullulan made of and how is it produced?
Pullulan consists of maltotriose units (three glucose molecules joined by α-1,4 glycosidic bonds), and these units are linked to each other by α-1,6 glycosidic bonds. It is produced by fermentation: the fungus Aureobasidium pullulans converts starch-containing raw materials, often tapioca, into pullulan, which is then purified and dried. It is therefore plant-and-microbe derived, with no animal components.
On food labels it carries the number E 1204.
Pullulan capsules compared
Capsule shells for supplements are usually made from one of three materials:
Capsule materials compared
Typical properties, simplified.
| Material | Origin | Vegan | Notable feature |
|---|---|---|---|
| Material Gelatine | Origin animal (bovine, porcine) | Vegan no | Notable feature classic, inexpensive |
| Material HPMC (hypromellose) | Origin plant cellulose, chemically modified | Vegan yes | Notable feature common vegan shell |
| Material Pullulan | Origin starch, via fungal fermentation | Vegan yes | Notable feature regarded as a good oxygen barrier |
Why does the capsule shell matter?
The shell protects the contents from moisture and oxygen until the capsule dissolves in the digestive tract. Pullulan is regarded as a good oxygen barrier, which can be an advantage for sensitive ingredients. It does not make any health promise: the capsule is an excipient, not an active ingredient.
Curcumin+ from 2 Kapseln Bitte uses a pullulan capsule. Apart from the shell, the capsule contains only the curcumin–γ-cyclodextrin complex. Cyclodextrin is also derived from starch.