Peptone
Safe protein extract; vegans should verify the source.
- Category
- Emulsifiers
- Vegan
- maybe
- Vegetarian
- maybe
What it is
A mixture of polypeptides and amino acids formed by the partial hydrolysis of proteins.
How it is used in food
Peptone is protein broken down by enzymes or acid into short peptides and amino acids, used in food as a foaming and emulsifying aid and as a nitrogen source for fermentation — it feeds the yeasts and bacteria that make bread, beer, yoghurt and vinegar. Because it is already partly digested, it is also readily absorbed, which is why peptide-based protein hydrolysates are used in clinical and hypoallergenic nutrition.
Commonly found in- Nutrient media
- Specialty foods
Health and safety
Safe for consumption, as it is just partially digested protein.
Peptones from food-grade sources are regarded as safe and are not subject to an ADI; the underlying material is ordinary protein, and hydrolysis is what happens in the gut anyway. Two practical caveats are well documented. First, source matters: peptone may be made from casein, meat, gelatine, soy or yeast, so vegans, vegetarians and people avoiding specific allergens need to know the origin, which is rarely stated on labels. Second, hydrolysates carry free glutamate and can contribute savoury 'umami' flavour, and enzymatic hydrolysis of allergenic proteins does not reliably remove allergenicity unless extensively performed and verified.
Regulatory status
| Region | Status | Notes |
|---|---|---|
| Australia & New Zealand FSANZ |
Permitted | Permitted under the FSANZ Food Standards Code. |
| European Union EFSA / European Commission |
Not approved | Not on the EU authorised list of food additives (Annex II). |
| United States FDA (Food and Drug Administration) |
Permitted | Authorised for food use by the FDA (often GRAS for standard additives). |
Identification on labels
- E-number
- E429
Worth knowing
Peptone is the workhorse of microbiology laboratories worldwide: nutrient agar, tryptone soy broth and most standard growth media are built on it, and food-safety testing for Salmonella or Listeria almost always starts by reviving the sample in buffered peptone water. The name dates to 1880s German physiology, from the Greek for 'to digest'.
Conclusion
Safe protein extract; vegans should verify the source.
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Open the appEntry last reviewed 2026-07-28.
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