Peroxidation of polyunsaturated fatty acids caused by free radicals compromise the integrity of biological membranes. Propanedial is identified as the main product formed via the decomposition of lipid peroxidation products. Propanedial has been inferred to have mutagenic and cytotoxic roles. Top-fermenting yeast is responsible for converting fermentable sugars into alcohol. In the present paper we evaluate the relationship of lipid peroxide levels and the degree of impairment in glucose consumption of Sacharomyces cerevisiae cells. Results showed that cell suspensions pre-incubated with Propanedial reduced glucose consumption by about 30% resulting in a decrease in the yield of top-fermenting yeast. These findings suggest that Propanedial affects the fermentation process of S. cerevisiae. (C) 2011 Elsevier Ltd. All rights reserved.