Typical aroma compounds of fermented milk drinks are: acetaldehyde, diacetyl, lactic acid, acetic acid, acetoin, and others. The content of the above mentioned compounds determines the required and acceptable flavour and taste qualities of fermented milk drinks. The composition of soymilk is different from the composition of cow’s milk; therefore, the soymilk is characterized by different taste and flavour characteristics than the cow’s milk. The objective of this paper was to assess the aroma stability of soy yoghurts during the 4 weeks of cold storage. In order to enhance the detailed interpretation of the research results on the aroma stabilization, the viability of yoghurt bacteria was determined, as were changes in pH of soy yoghurts during their storage. A chromatographic analysis GC-MS using a SPME technique performed showed that there were no significant changes in the profile of volatile compounds contained in soy yoghurts during the 4 weeks of cold storage. The glucose added had no significant effect on the intensification of changes in the aroma profile of yoghurts during their storage. In the composition of volatile compounds, the following compounds were identified: ethanol, 1-heksanol, acetoin, 2,3-butanedione (diacetyl), 2,3-pentanedione, hexanal, nonanal, butanoic acid, and acetic acid.
soy yoghurt, storage, volatile compounds, aroma, SPME