摘要
While soy yogurts offer health benefits,their wide market acceptance is limited by the less desirable flavor.This study investigated the generation of yogurt flavor volatiles and the metabolic pathways in the soymilk lactic acid bacteria(LAB)fermentation system,using dairy milk as a reference,through comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry(GC×GC-TOFMS)and liquid chromatography-electrospray ionization-tandem mass spectrometry(LC-ESI-MS/MS)-based flavoromics and metabolomics.The results revealed that soy yogurts exhibited higher total volatile concentrations,but dairy yogurts demonstrated higher odor activity values(OAVs).Ten key metabolic pathways in soy-based fermentation,but 9 pathways in dairy-based system were identified.The pyruvate metabolism module served as a key node for the generation of yogurt flavor compounds in both systems;amino acid metabolic pathways were more active in soy than in dairy,while different carbohydrate metabolic pathways existed in soy-based and dairy-based systems.Expression levels of key enzymes for yogurt flavor formation were affected synergistically,antagonistically,or independently by the soy and dairy milk components.This work provides experimental evidence to solidify the theoretical framework of soymilk LAB fermentation.
基金
supported by the National Natural Science Foundation of China(32272243 and 32072164)
the Key Research and Development Program of Shandong Province(2022CXGC010603)
the China Postdoctoral Science Foundation(2020M671342).
