The invention relates to the use of a propenylphenyl glycoside of formula (I) wherein R is (1E)-prop-1-enyl, (1Z)-prop-1-enyl or prop-2-enyl; and Glc is an .alpha.- or .beta.-glycosidically bonded mono- or oligo-saccharide,for enhancing the sweet taste of a sweet-tasting substance or the sweet odour impression of a flavouring that produces a sweet odour impression.