Lisozim

Detailed information

What it is & how it is made

The EU specification defines lysozyme as 'a linear polypeptide obtained from hens' egg whites consisting of 129 amino acids'. It can hydrolyse the beta(1-4) linkages between N-acetylmuramic acid and N-acetylglucosamine in the outer membranes of bacteria, is particularly effective against gram-positive organisms and is usually obtained as the hydrochloride. Its content is not less than 950 mg/g on the anhydrous basis and its molecular weight about 14,000 (Commission Regulation (EU) No 231/2012, E 1105).

Where it is used

It belongs to the preservative functional class. EFSA's 2023 food-enzyme evaluation reports that lysozyme produced from hens' eggs is used in brewing, in milk processing for cheese production and in wine production (EFSA Journal 2023;21(4):7918). Its main purpose is to limit the growth of gram-positive bacteria that cause the late-blowing defect in ripened cheeses.

Health note

Eggs are among the substances requiring mandatory allergen declaration in Annex II to EU Regulation (EU) No 1169/2011, and lysozyme obtained from eggs is subject to that declaration requirement. EFSA assessed a request for a permanent labelling exemption for hen egg lysozyme used in wine and did not support it, concluding that sensitisation to lysozyme is common among people allergic to egg (EFSA Journal 2011;9(9):2386).

Halal assessment

The source of this additive is explicitly defined in the legislation: hens' egg white. Egg is a source that requires no slaughter of an animal and is regarded as halal, which distinguishes lysozyme from animal-derived additives of uncertain origin. Even so, the halal certification of the individual product and the processing aids used in the production chain should be checked separately.