Metabolization of Free and Peptide-Bound Oxidized Methionine Derivatives by in a Model System.

In the brewing process, methionine is a decisive amino acid for (off-)flavor formation. A significant part of methionine is oxidized to methionine sulfoxide (MetSO) in malt. We hypothesized that MetSO and MetSO are metabolized to volatile compounds during yeast fermentation and examined whether the yeast is able to catabolize l-MetSO and l-MetSO in free and dipeptide-bound forms.