Exploring the role of lactic acid bacteria involved in bread fermentation in improving flavor via intelligent sensory technologies and GC×GC-ToF-MS

The effect of individually mixing Lactobacillus paracasei C5 and Lactobacillus pentosus D1 with yeast as starter cultures on bread flavor was investigated via electronic-nose, electronic-tongue, and GC × GC-ToF-MS methods The electronic-nose results showed that the bread smell could be completely distinguished. Electronic-tongue analysis revealed that the taste of mixed-fermented bread was positively correlated with sourness, sweetness, saltiness, and umami, while the taste of yeast-fermented bread was positively correlated with bitterness and astringency. GC × GC-TOF-MS was used to further detect volatile organic compounds, from which 15 (L. paracasei bread) and 18 (L. pentosus bread) major contributing aroma compounds were screened (ROAV ≥1 and VIP >1). Additionally, Lactobacillus was found to be positively correlated with 35 flavor substances and positively regulated the aroma profile of the bread, especially sweet-caramel, coffee-like, and roasted aromas. In conclusion, LAB involved in fermentation can improve the flavor of bread. •The composition of the dough bacterial community was different.•The flavor of the bread improved with the addition of LAB sourdough.•Lactobacillus were positively correlated with a variety of bread flavor substances.•Lactic acid bacteria positively modulated the bread typical baking flavor profiles.