Nisin and glutathione in meat and a model protein system
What it found
In lab tests, nisin lost activity when it reacted with glutathione, and this reaction did not need enzymes.
Cooked meat kept more nisin activity because cooking used up free sulfhydryl groups.
What they found
Animal and lab studies
Adduct forms without enzymes
The nisin-glutathione adduct does form, but the reaction is not enzyme mediated.
Cooking and sulfhydryl groups
Cooked meat kept more nisin activity because free sulfhydryl groups were lost during cooking. This happened as glutathione reacted with proteins, not because enzymes were inactivated.
Microbial enzymes not involved
Microbial enzymes did not appear to play a role. Similar losses were seen in raw and cooked meat extracts, and both had undetectable levels of microorganisms.
What the authors conclude
“Formation of the nisin-glutathione adduct has been confirmed but is shown not to be enzyme mediated.”
Also in their conclusions
- They conclude that formation of the nisin-glutathione adduct is not enzyme mediated.
- They conclude that retention of activity in cooked meat is due to the loss of free sulfhydryl groups during cooking, as glutathione reacts with proteins, and not to inactivation of endogenous enzymes.
- They conclude that microbial enzymes do not appear to play a role.
How it was done
Loss of nisin activity in meat has been partly blamed on a nisin-glutathione adduct forming. Activity is lost faster in raw meat than cooked meat, which was taken as evidence the reaction is enzyme mediated.
They studied nisin with glutathione in a model protein system and in meat. They compared raw and cooked meat extracts, both of which had undetectable levels of microorganisms.
What it can’t tell you
- We summarised it from the abstract only.
- These are lab tests on a model protein system and meat extracts, not studies in people.
- They can't show how nisin behaves in the human gut or in the body.
Who paid
- Authors work at
- University of Surrey, United Kingdom
The paper
- Title
- Interactions of nisin with glutathione in a model protein system and meat
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Abstract only
- Cite
- Stergiou VA, Thomas LV, Adams MR (2006). Interactions of nisin with glutathione in a model protein system and meat. Journal of food protection. doi:10.4315/0362-028x-69.4.951PubMed 16629047DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error