In commercial mayonnaise the percentage of free fatty acids, mono- di- and triacylglycerols fractions were determined. In fractions of triacylglycerols fatty acids composition was determined. Sizes of particles were measured and particles distributions were set in the emulsions after storage samples for a month and four months, at 20°C and 2°C. The laser diffraction method was applied to investigate the effect of storage temperature and time on the emulsions stability. It has been found that generally rapeseed oil was used in the production of mayonnaise, which is available in polish market. In low fat and regular mayonnaise the higher amounts of mono- and diacylglycerols fractions were determined. Mono- and diacylglycerols as emulsifiers assured high stability of these products. In most cases, at the storage conditions the aggregation of dispersed phase particles and crystallisation of acylglycerols at the low temperature have been proceeded. These processes resulted in the separation of oil phases and destabilisation of the emulsions. The emulsions characterised by the lower droplet size were not destabilised at the storage conditions.