Fermentation effects on antioxidant activity of Choerospondias axillaris beverage

Domesticated bacteria( Streptococcus thermophilus and Lactobacillus bulgaricus) were utilized to ferment Choerospondias axillaris to produce functional Lactobacillus beverages of Choerospondias axillaris. The free phenolic and flavonoid compounds of beverages of fermentation and unfermentation were determined by the method of Folin- Ciocaileu and Al( NO₃)_3- Na NO₂. Three antioxidant model were used to study the change of antioxidant activity of the beverages after fermention of Choerospondias axillaris. The results showed that the content of the free phenolic and flavonoid compounds were increased to 1.3 times,1.1 times respectively after fermentation compared to that of unfermented one. It was found that the antioxidant activity of the beverage was enhanced obviously.The IC₅₀ of DPPH radical- scavenging activity of fermented and unfermented beverages were0.137,0.185 m L / m L,respectively. The IC₅₀ of ABTS radical- scavenging activity of fermented and unfermented beverages were 0.012,0.015 m L / m L,respectively. The antioxidant activity was increased to 1.1~1.4 times,and the ferric reducing / antioxidant ability was increased to 1.4~1.7 times by fermentation.Besides,all the changes showed significant difference( p < 0.05).