Effects of lactic acid bacteria on antioxidant activity in vitro and aroma component of Eucommia ulmoides tea

Eucommia ulmoides tea is a popular functional health drink in Asian countries, but its unique herbal aroma is difficult for consumers to accept. The effects of four lactic acid bacteria strains ( Lactobacillus plantarium , Lactobacillus bulgaricus , Lactobacillus acidophilus and Streptococcus thermophilus ) fermentation on the physicochemical property, antioxidant activity in vitro and aroma component of E. ulmoides leaves were studied. Within the four strains, the sample by L. bulgaricus fermentation showed the higher concentrations of chlorogenic acid, geniposidic acid and stronger antioxidant activity in vitro. Moreover, the sample by L. bulgaricus fermentation produced a stronger fruity and floral flavor. These results suggested that L. bulgaricus was the best strain for fermentation E. ulmoides tea. The differences between different strains should be considered when selecting lactic acid bacteria for raw material fermentation of fruits and vegetables.