The present invention in a first aspect relates to novel flavour modulating substances according to formula (I) or formula (II) or edible salts thereof or both: R.sup.1--CR.sup.2(OR.sup.3)--CO--NR.sup.4--CHR.sup.5R.sup.6 (I). It was found that substances represented by formula (I) or formula (II) can advantageously be used to impart desirable flavour, especially taste attributes to foodstuffs, beverages, pharmaceutics, tobacco products and oral care products they are incorporated in. In addition these substances are capable of modulating and complementing the sensory impact of other, flavour imparting, substances. Thus, the present flavour modulating substances are advantageously applied in flavour compositions, foodstuffs, beverages, pharmaceutics and oral care products. Typical examples of flavour modulating substances according to the present invention include N-lactoyl glucosamine, N-lactoyl glucosaminic acid, N-gluconyl glucosamine, N-gluconyl glucosaminic acid, hemiacetals or lactones thereof, edible salts thereof and mixtures thereof.