Determination of sourdough microbial floras that are used in artisan breads and characterization of volatile profiles with sensory properties

The objective of this study is to isolate LAB and yeast strains from local bakery which is production of sourdough methods in İzmir, to identificate the isolated strains by biochemical and molecular techniques, to develope a starter culture by using identified strains, to produce sourdough with starter culture and compare the volatile profiles of local sourdough breads and the starter culture breads and to evaluate the effects of volatile profiles on bread quality parameters. In this study, 8 LAB and 4 yeasts strains were isolated from 10 different sourdoughs samples collected in İzmir and they were identified as biochemically. The high frequency strains L. mesenteroides and D. hansenii were phylogenetically identified via molecular techniques. Then volatile profiles were analyzed via SPME/GC-MS for the breads which were prepared with starter culture as well as local sourdoughs. In the analysis of volatile profiles, 57 molecules were determined within the breads produced from starter culture bread whereas 61 compounds were detected within the breads produced from local sourdough. 46 of them were determined as mutual volatile compounds. These compounds were evaluated by means of principal component analysis to determine the similarities and the differences. 9 of the principal compounds were found to be enough for explaining 97.5% of total variance in characterization of volatiles and 9 sub-groups were obtained via hierarchal cluster analysis. Besides, the similarity between the volatile profile of L5N7 coded bread and starter culture bread was proved via statistically. The sensory features of bread samples (colour, tissue, flavor, pore and whole impression) were evaluated by the panelists by using scoring test method. Statistical analysis showed that the odor, taste and overall evaluation were the distinctive features of L1N1 coded bread at 95% confidence level.