Abstract: The differences in the aroma components produced in buckwheat and wheat during fermentation by different starter cultures were analyzed by head space solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The aroma compounds were identified based on their retention indices and mass spectra. A total of 38 aroma compounds were identified in unfermented buckwheat dough, and 80 and 63 aroma compounds in buckwheat dough fermented by yeast and lactic acid bacteria, respectively. A total of 11 aroma compounds were found to be present in unfermented wheat dough, and 42 and 17 aroma compounds in wheat dough fermented by yeast and lactic?acid bacteria, respectively. Accordingly, new aroma compounds were formed during the fermentation of both wheat and buckwheat dough and buckwheat dough contained a larger number of aroma compounds than wheat dough. Hydrocarbons (monoterpenoids and sesquiterpenes) and esters were the main aroma components in buckwheat dough both before and after fermentation by yeast, whereas esters were the main aroma components in buckwheat dough both before and after fermentation by lactic?acid bacteria. Hydrocarbon, esters, alcohols, acids, aldehydes and ethers were produced as the main aroma compounds during the fermentation of wheat dough by yeast, while a smaller number of aroma components including hydrocarbon, esters, aldehydes and ethers were produced during fermentation by lactic?acid?bacteria. Fermented buckwheat dough contained more aroma components. Both buckwheat and wheat dough showed a significant change in aroma composition after fermentation by yeast or lactic acid bacteria. Furthermore, the aroma composition changed with fermentation time.

Key words: fermentation, aroma components, buckwheat, wheat, head space solid-phase microextraction (HS-SPME), gas chromatography-mass spectrometry (GC-MS)