The present invention relates to a composition in the form of an oil-in-water emulsion, preferably a mayonnaise-type emulsion, containing ground white or yellow mustard seed. This way the amount of oil in the emulsion can be reduced, while keeping the structure of full-fat mayo, without using large amounts of thickeners or water-structurants. Moreover the invention relates to the use of ground white or yellow mustard seed as an ingredient of the emulsion to reduce the concentration of oil in the emulsion.