Production of Dairy-Based, Natural Sulphur Flavor Concentrate by Yeast Fermentation

Abstract

Production of sulphur flavor concentrate by yeast fermentation was investigated using dairy media (milk and cream) spiked with L-methionine. The yeasts studied included so-called dairy yeasts Candida kefyr, Kluyveromyces marxianus, Debaryomyces hansenii, Geotrichum candidum, and Yarrowia lipolytica as well as wine yeasts Saccharomyces cerevisiae and Saccharomyces bayanus. Methionol was produced as the predominant volatile sulphur flavor compound. Other volatile sulphur flavor compounds produced were dimethyl disulphide, S-methyl thioacetate, 3-methylthio-1-propanoic acid, methional, 3-methylthio-1-propene, and ethyl 3-methylthio-1-propanoate. In addition, numerous other volatile flavor compounds were produced, including ethanol, branched-chain alcohols, aromatic alcohol, ethyl esters, branched-chain esters, branched-chain fatty acids, and branched-chain aldehydes. The sensory attribute of a methionol sulphur flavor concentrate in cream is concentration-dependent, ranging from a savory-slight potato note to a strong potato-savory note to a cooked cheese-potato note.