Analysis of volatile flavor components and characteristics of dough fermented with flavor fermentation liquid

Objective: This study aimed to investigate the varieties and contents of volatile components in fermented dough with flavor fermentation broth at different fermentation time. Methods: Headspace solid phase microextraction-gas chromatography (HS-SPME-GC-MS) was used to determine the volatile flavor substances in the dough of the flavor ferment at 12, 24, 36, 48 and 72 h. Also, sensory evaluation of the odor and determination of pH value, total acidity (TAA) and rheological properties of the dough were measured. Results: The strength of eight odors (frankincense, cheese, flower, fruit sweet, wine, malt, grass and sour) showed different performance, depending on the types and contents of the flavour substances produced during the different fermentation periods. The pH value of the dough gradually decreases with the time of fermentation, while TTA was the opposite. The tensile resistance, stretch ratio and tensile area of dough increased first but decreased with the extension of fermentation time, while the elongation of dough decreased first then increased. These results indicated that moderate fermentation (36 h) was beneficial to the formation and stability of the gluten network. A total of 92 volatile substances were detected in the dough with 5 fermentation times, including 22 alcohols, 27 esters, 12 aldehydes, 14 ketones, 10 alkanes, and 7 acids. A total of 27, 43, 38, 41 and 37 volatile flavor components were detected from the dough fermented for 12, 24, 36, 48 and 72 h, respectively. The contents of acids and esters increased first then decreased with the prolongation of fermentation time and reaching the highest at 48 h (47.31% and 20.96%, respectively). On the other hand, the contents of aldehydes, ketones and acids all gradually decreased. Conclusion: The volatile substances of different fermentation times were alcohols mainly, and the total flavor substances and the relative content of alcohols and esters reached the highest at 48 h, indicating that alcohols and esters might be the major contributors to the flavor of dough during fermentation.