Lysozyme
The short version
An egg-derived antimicrobial enzyme — used in cheese rinds and wine. Egg allergen.
It's permitted and generally considered safe, but there are a few reasons to be mindful — like sensitivities in some people, debated studies, or intake limits. The Safety section below explains the specifics.
Where it comes from
Discovered by Alexander Fleming in 1922, lysozyme is a natural antimicrobial enzyme found in tears, saliva, and especially hen egg whites (where it is industrially extracted). Cleaves the peptidoglycan layer of Gram-positive bacterial cell walls, lysing the cell.
How it's used
Added to hard cheeses (Grana Padano, Provolone, Gouda, Edam) to prevent late blowing by Clostridium tyrobutyricum — a defect that causes cracks and off-flavors. Also used in wine to control malolactic fermentation timing. Permitted in some markets in infant formula. Typical use 250–500 mg/kg in cheese.
Safety profile
ADI not specified — considered safe enzymatically. The primary concern is allergenicity: as a hen-egg protein, lysozyme can trigger reactions in egg-allergic individuals at trace levels. EU and most jurisdictions require declaration as an egg-derived ingredient.
Physical & chemical properties
White to off-white powder, soluble in water. Optimal activity at pH 6–9. Heat-labile above 70°C — denatured by cheese-cooking but stable in cold ageing.
Regulation worldwide
Permitted in the EU and globally with mandatory egg-allergen declaration. Not permitted in some organic-certification programs.
Educational information only. Not medical or dietary advice.