Alkanals as carriers of rancid flavour of fat-containing foods were stored in mixtures with nonlipidic substances. The intensity of odour due to alkanals decreased with increasing time of storage, the changes being more pronounced in case of casein than in that of cellulose. Results of sensory tests did not depend on the molecular mass of aldehyde. The water content affected the sensory evaluation only slightly. The formation of aldolization products or polymers and of gluey flavour compounds modified the character of flavour and confused less experienced judges. Both the binding of alkanals and the aldolization reactions were enhanced by presence of primary amino groups.