Abstract: In this paper, a Lactobacillus ferment was studied. After further fermentation, the optimal cultural conditions were brought about: sucrose 1.5%、peptone 1%、tomato juice 20%、carrot Juice 2%、tween 20 0.5%、KH 2 PO 4 0.02%、 NaCl 0.3%、MgSO 4 •7H 2 O 0.2% pH6.5 and temperature 37℃, 72h. After being used in fermented carrot juice, the flavor compounds in the fermented juice and raw material juice were compared. The results showed that there were some new substances in fermented carrot juice which affected the final fermented product flavor.

Key words: Lactobacillus, fermentation, flavor